Excitability of the motor cortex in de novo patients with celiac disease

Motor cortex excitability in restless legs syndrome: A systematic review and insights into pathophysiology via transcranial magnetic stimulation

Restless Legs Syndrome (RLS) is a neurological disorder characterized by a complex and only partially understood pathophysiology. Numerous studies have investigated motor cortex excitability in RLS using transcranial magnetic stimulation (TMS), but a comprehensive systematic review assessing their methodological quality and synthesizing their findings is lacking. A systematic search of PubMed focused on various TMS parameters, including resting and active motor thresholds, motor evoked potential characteristics, contralateral and ipsilateral silent periods, and multiple measures of intracortical inhibition and facilitation. The quality of each study was evaluated using custom checklists and the modified Newcastle-Ottawa Quality Assessment Scale. Out of the studies screened, 21 (comprising 319 RLS patients and 278 healthy controls) met the inclusion criteria. Despite considerable variability in TMS methodologies-such as differences in the muscles tested, interstimulus intervals, testing timing, and the potential confounding effects of medications-a consistent finding was a reduction in short-interval intracortical inhibition, a key indicator of central inhibitory GABAergic activity. Additionally, altered post-exercise facilitation and delayed facilitation suggest abnormal motor plasticity in RLS patients. These findings suggest that despite the methodological heterogeneity, TMS abnormalities may play a crucial role in the pathophysiology of RLS. In this context, RLS symptoms are likely to originate at different levels within a complex neural network, ultimately leading to altered, possibly transient and circadian, excitability in a multifaceted neurophysiological system. While further rigorous research and reproducible evidence are needed, these insights may contribute to the identification of new diagnostic markers and the development of innovative therapeutic strategies for RLS.

Relationship Among Macronutrients, Dietary Components, and Objective Sleep Variables Measured by Smartphone Apps: Real-World Cross-Sectional Study

BACKGROUND

Few studies have explored the relationship between macronutrient intake and sleep outcomes using daily data from mobile apps.

OBJECTIVE

This cross-sectional study aimed to examine the associations between macronutrients, dietary components, and sleep parameters, considering their interdependencies.

METHODS

We analyzed data from 4825 users of the Pokémon Sleep and Asken smartphone apps, each used for at least 7 days to record objective sleep parameters and dietary components, respectively. Multivariable regression explored the associations between quartiles of macronutrients (protein; carbohydrate; and total fat, including saturated, monounsaturated, and polyunsaturated fats), dietary components (sodium, potassium, dietary fiber, and sodium-to-potassium ratio), and sleep variables (total sleep time [TST], sleep latency [SL], and percentage of wakefulness after sleep onset [%WASO]). The lowest intake group was the reference. Compositional data analysis accounted for macronutrient interdependencies. Models were adjusted for age, sex, and BMI.

RESULTS

Greater protein intake was associated with longer TST in the third (+0.17, 95% CI 0.09-0.26 h) and fourth (+0.18, 95% CI 0.09-0.27 h) quartiles. In contrast, greater fat intake was linked to shorter TST in the third (-0.11, 95% CI -0.20 to -0.27 h) and fourth (-0.16, 95% CI -0.25 to -0.07 h) quartiles. Greater carbohydrate intake was associated with shorter %WASO in the third (-0.82%, 95% CI -1.37% to -0.26%) and fourth (-0.57%, 95% CI -1.13% to -0.01%) quartiles, while greater fat intake was linked to longer %WASO in the fourth quartile (+0.62%, 95% CI 0.06%-1.18%). Dietary fiber intake correlated with longer TST and shorter SL. A greater sodium-to-potassium ratio was associated with shorter TST in the third (-0.11, 95% CI -0.20 to -0.02 h) and fourth (-0.19, 95% CI -0.28 to -0.10 h) quartiles; longer SL in the second (+1.03, 95% CI 0.08-1.98 min) and fourth (+1.50, 95% CI 0.53-2.47 min) quartiles; and longer %WASO in the fourth quartile (0.71%, 95% CI 0.15%-1.28%). Compositional data analysis, involving 6% changes in macronutrient proportions, showed that greater protein intake was associated with an elevated TST (+0.27, 95% CI 0.18-0.35 h), while greater monounsaturated fat intake was associated with a longer SL (+4.6, 95% CI 1.93-7.34 min) and a larger %WASO (+2.2%, 95% CI 0.63%-3.78%). In contrast, greater polyunsaturated fat intake was associated with a reduced TST (-0.22, 95% CI -0.39 to -0.05 h), a shorter SL (-4.7, 95% CI to 6.58 to -2.86 min), and a shorter %WASO (+2.0%, 95% CI -3.08% to -0.92%).

CONCLUSIONS

Greater protein and fiber intake were associated with longer TST, while greater fat intake and sodium-to-potassium ratios were linked to shorter TST and longer WASO. Increasing protein intake in place of other nutrients was associated with longer TST, while higher polyunsaturated fat intake improved SL and reduced WASO.

Ultrarare Cause of Childhood Chorea: Celiac Disease

INTRODUCTION

Chorea, a movement disorder that commonly affects children, may be caused by various diseases with metabolic, structural, pharmacologic, or autoimmune origins. Celiac disease is an autoimmune enteropathy that may rarely cause neurologic symptoms in children, primarily ataxia and peripheral neuropathy, even in the absence of gastrointestinal symptoms.

CASE REPORT

A 9-year-old male patient diagnosed with Sydenham chorea was admitted to our clinic because of valproic acid resistance. He had involuntary, brief, random, and irregular movements in his arms over the past 2 weeks. A low-dose, high-potency dopamine-2 receptor-blocking agent was added to the patient's treatment regimen. After 2 weeks, he had maculopapular rashes on their hands and arms, as well as arthritis in his left hand. Oral prednisone was prescribed, and the patient's arthritis and rashes were completely resolved. Although movement disorder symptoms persisted in the distal left upper extremity, the chorea in the right upper extremity was recovered. Extensive investigations were conducted to rule out possible metabolic, autoimmune, inflammatory, infectious, and paraneoplastic diseases, all of which yielded normal results. Brain magnetic resonance imaging (MRI) results were normal, and genetic analysis results for chorea were negative. The patient's tissue glutaminase IgG levels exceeded 200 U/mL (normal range: 0-10 U/mL) and IgA levels at 24 U/mL (normal range: 0--10 U/mL), leading to a diagnosis of celiac disease. His duodenal biopsies showed changes consistent with gluten-sensitive enteropathy. After the diagnosis of celiac disease, the patient began a gluten-free diet and remained free of chorea at the 6-month follow-up.

DISCUSSION

Chorea is a rare neurologic celiac disease manifestation that can be reversible. The celiac disease should be considered in the diagnostic workup of chorea for all ages, particularly in the treatment-resistant population, even in the absence of gastrointestinal symptoms. This report presents the first known case of chorea caused by celiac disease in a pediatric patient.

Vascular Cognitive Impairment-The Molecular Basis and Potential Influence of the Gut Microbiota on the Pathological Process

Cognitive impairment is a major healthcare challenge worldwide, with vascular cognitive impairment (VCI) being its second leading cause after Alzheimer's disease. VCI is a heterogeneous group of cognitive disorders resulting from various vascular pathologies. Therefore, it is particularly difficult to determine its underlying cause and exact molecular basis. Nevertheless, the current understanding of the pathophysiological processes underlying VCI has changed and evolved in the last decades. The aim of this narrative review is to summarize the current state of knowledge on VCI pathogenesis and to analyze the potential role of the gut microbiota in this process, considering the most recent scientific reports and in accordance with the current understanding of these processes. Chronic cerebral hypoperfusion, which results in impaired blood supply, i.e., oxygen and nutrient deficiency, is the main underlying mechanism of VCI. Furthermore, chronic cerebral hypoperfusion triggers a cascade of molecular changes, starting with an energy imbalance, leading to glutamate excitotoxicity, acidotoxicity, and oxidative stress. Also, all of the above provoke the activation of microglia and the release of pro-inflammatory cytokines that recruit systemic immune cells and lead to their infiltration into the central nervous system, resulting in neuroinflammation. Blood-brain barrier dysfunction may occur at various stages of chronic cerebral hypoperfusion, ultimately increasing its permeability and allowing potentially toxic substances to enter the brain parenchyma. Gut microbiota and their metabolites, which have been identified in numerous inflammatory conditions, may also influence the pathophysiological processes of VCI.

Celiac disease and depressive disorders as nutritional implications related to common factors - A comprehensive review

Celiac disease (CD) is an immune-mediated disease affecting the small intestine. The only treatment strategy for CD is the gluten-free diet (GFD). One of the more common mental disorders in CD patients is major depressive disorder (MDD). The influence of GFD on the occurrence of MDD symptoms in patients with CD will be evaluated. This diet often reduces nutritional deficiencies in these patients and also helps to reduce depressive symptoms. Both disease entities are often dominated by the same deficiencies of nutrients such as iron, zinc, selenium, iodine, or B and D vitamins. Deficiencies of particular components in CD can favor MDD and vice versa. Gluten can adversely affect the mental state of patients without CD. Also, intestinal microbiota may play an important role in the described process. This work aims to comprehensively assess the common factors involved in the pathomechanisms of MDD and CD, with particular emphasis on nutrient imbalances. Given the complexity of both disease entities, and the many common links, more research related to improving mental health in these patients and the implementation of a GFD would need to be conducted, but it appears to be a viable pathway to improving the quality of life and health of people struggling with CD and MDD. Therefore, probiotics, micronutrients, macronutrients, and vitamin supplements are recommended to reduce the risk of MDD, given that they may alleviate the symptoms of both these disease entities. In turn, in patients with MDD, it is worth considering testing for CD.

Clinical study on low-frequency repetitive transcranial magnetic stimulation for the treatment of walking dysfunction following stroke through three-dimensional gait analysis

BACKGROUND

The recovery of walking capacity is of great significance in stroke rehabilitation. We evaluated changes in post-stroke gait function after low-frequency repetitive transcranial magnetic stimulation (LF-rTMS) treatment.

METHODS

Stroke patients were randomly assigned to control (conventional treatment)/LF-rTMS (LF-rTMS treatment based on conventional treatment) groups. Gait spatiotemporal parameters/affected side joint motion angle/affected side dynamic parameters were analyzed by 3D gait analyses. Motor evoked potential (MEP)/central motor conduction time (CMCT) changes were detected. Correlations between MEP latency/CMCT and gait parameters after LF-rTMS were analyzed by Pearson analysis.

RESULTS

The two groups exhibited boosted stride speed/frequency/length, affected side stride length/swing phase percentage/hip/knee/ankle joint plantar flexion angle, and affected side ahead ground reaction force/ upward ground reaction force (AGRF/UGRF)/ankle joint plantar flexion moment, along with reduced affected side gait period/stance phase percentage after treatment, and the LF-rTMS group manifested better efficacy. MEP latency/CMCT of stroke patients treated with LF-rTMS was adversely linked to stride speed, affected side stride length/swing phase percentage/knee flexion angle, AGRF and UGRF, and positively correlated with affected side stance phase percentage.

CONCLUSION

LF-rTMS significantly improved gait spatiotemporal parameters/affected joint motion angles/neurophysiologic parameters (MEP latency/CMCT) in patients with post-stroke walking dysfunction. MEP latency/CMCT after LF-rTMS treatment were prominently correlated with gait parameters. Relative to the traditional scale assessment, we provided a more accurate, objective and reliable evaluation of the effects of LF-rTMS on lower limb mobility and functional recovery effects in stroke patients from the perspective of 3D gait analysis and neurophysiology, which provided more evidence to support the clinical application of LF-rTMS in post-stroke walking dysfunction treatment.

Sex-specific reference values for total, central, and peripheral latency of motor evoked potentials from a large cohort

Background

Differentiating between physiologic and altered motor evoked potentials (MEPs) to transcranial magnetic stimulation (TMS) is crucial in clinical practice. Some physical characteristics, such as height and age, introduce sources of variability unrelated to neural dysfunction. We provided new age- and height-adjusted normal values for cortical latency, central motor conduction time (CMCT), and peripheral motor conduction time (PMCT) from a large cohort of healthy subjects.

Methods

Previously reported data from 587 participants were re-analyzed. Nervous system disorders were ruled out by clinical examination and magnetic resonance imaging. MEP latency was determined as stimulus-to-response latency through stimulation with a circular coil over the "hot spot" of the First Dorsal Interosseous and Tibialis Anterior muscles, during mild tonic contraction. CMCT was estimated as the difference between MEP cortical latency and PMCT by radicular magnetic stimulation. Additionally, right-to-left differences were calculated. For each parameter, multiple linear regression models of increasing complexity were fitted using height, age, and sex as regressors.

Results

Motor evoked potential cortical latency, PMCT, and CMCT were shown to be age- and height-dependent, although age had only a small effect on CMCT. Relying on Bayesian information criterion for model selection, MEP cortical latency and PMCT were explained best by linear models indicating a positive correlation with both height and age. Also, CMCT to lower limbs positively correlated with height and age. CMCT to upper limbs positively correlated to height, but slightly inversely correlated to age, as supported by non-parametric bootstrap analysis. Males had longer cortical latencies and CMCT to lower limbs, as well as longer PMCT and cortical latencies to upper limbs, even when accounting for differences in body height. Right-to-left-differences were independent of height, age, and sex. Based on the selected regression models, sex-specific reference values were obtained for all TMS-related latencies and inter-side differences, with adjustments for height and age, where warranted.

Conclusion

A significant relationship was observed between height and age and all MEP latency values, in both upper and lower limbs. These set of reference values facilitate the evaluation of MEPs in clinical studies and research settings. Unlike previous reports, we also highlighted the contribution of sex.

Celiac Disease and Neurological Manifestations: From Gluten to Neuroinflammation

Celiac disease (CD) is a complex multi-organ disease with a high prevalence of extra-intestinal involvement, including neurological and psychiatric manifestations, such as cerebellar ataxia, peripheral neuropathy, epilepsy, headache, cognitive impairment, and depression. However, the mechanisms behind the neurological involvement in CD remain controversial. Recent evidence shows these can be related to gluten-mediated pathogenesis, including antibody cross-reaction, deposition of immune-complex, direct neurotoxicity, and in severe cases, vitamins or nutrients deficiency. Here, we have summarized new evidence related to gut microbiota and the so-called "gut-liver-brain axis" involved in CD-related neurological manifestations. Additionally, there has yet to be an agreement on whether serological or neurophysiological findings can effectively early diagnose and properly monitor CD-associated neurological involvement; notably, most of them can revert to normal with a rigorous gluten-free diet. Moving from a molecular level to a symptom-based approach, clinical, serological, and neurophysiology data might help to disentangle the many-faceted interactions between the gut and brain in CD. Eventually, the identification of multimodal biomarkers might help diagnose, monitor, and improve the quality of life of patients with "neuroCD".

A comprehensive review of transcranial magnetic stimulation in secondary dementia

Although primary degenerative diseases are the main cause of dementia, a non-negligible proportion of patients is affected by a secondary and potentially treatable cognitive disorder. Therefore, diagnostic tools able to early identify and monitor them and to predict the response to treatment are needed. Transcranial magnetic stimulation (TMS) is a non-invasive neurophysiological technique capable of evaluating in vivo and in “real time” the motor areas, the cortico-spinal tract, and the neurotransmission pathways in several neurological and neuropsychiatric disorders, including cognitive impairment and dementia. While consistent evidence has been accumulated for Alzheimer’s disease, other degenerative cognitive disorders, and vascular dementia, to date a comprehensive review of TMS studies available in other secondary dementias is lacking. These conditions include, among others, normal-pressure hydrocephalus, multiple sclerosis, celiac disease and other immunologically mediated diseases, as well as a number of inflammatory, infective, metabolic, toxic, nutritional, endocrine, sleep-related, and rare genetic disorders. Overall, we observed that, while in degenerative dementia neurophysiological alterations might mirror specific, and possibly primary, neuropathological changes (and hence be used as early biomarkers), this pathogenic link appears to be weaker for most secondary forms of dementia, in which neurotransmitter dysfunction is more likely related to a systemic or diffuse neural damage. In these cases, therefore, an effort toward the understanding of pathological mechanisms of cognitive impairment should be made, also by investigating the relationship between functional alterations of brain circuits and the specific mechanisms of neuronal damage triggered by the causative disease. Neurophysiologically, although no distinctive TMS pattern can be identified that might be used to predict the occurrence or progression of cognitive decline in a specific condition, some TMS-associated measures of cortical function and plasticity (such as the short-latency afferent inhibition, the short-interval intracortical inhibition, and the cortical silent period) might add useful information in most of secondary dementia, especially in combination with suggestive clinical features and other diagnostic tests. The possibility to detect dysfunctional cortical circuits, to monitor the disease course, to probe the response to treatment, and to design novel neuromodulatory interventions in secondary dementia still represents a gap in the literature that needs to be explored.

Cerebral hemodynamic changes to transcranial Doppler sonography in celiac disease: A pilot study

Background

Sonographic mesenteric pattern in celiac disease (CD) suggests a hyperdynamic circulation. Despite the well-known CD-related neurological involvement, no study has systematically explored the cerebral hemodynamics to transcranial Doppler sonography.

Materials and methods

Montreal Cognitive Assessment (MoCA) and 17-item Hamilton Depression Rating Scale (HDRS) were assessed in 15 newly diagnosed subjects with CD and 15 age-, sex-, and education-matched healthy controls. Cerebral blood flow (CBF) velocities and indices of resistivity (RI) and pulsatility (PI) from the middle cerebral artery (MCA), bilaterally, and the basilar artery (BA) were recorded. We also assessed cerebral vasomotor reactivity (CVR) through the breath-holding test (BHT).

Results

Worse scores of MoCA and HDRS were found in patients compared to controls. Although patients showed higher values of CBF velocity from MCA bilaterally compared to controls, both at rest and after BHT, no comparison reached a statistical significance, whereas after BHT both RI and PI from BA were significantly higher in patients. A significant negative correlation between both indices from BA and MoCA score were also noted.

Conclusion

These treatment-naïve CD patients may show some subtle CVR changes in posterior circulation, thus possibly expanding the spectrum of pathomechanisms underlying neuroceliac disease and in particular gluten ataxia. Subclinical identification of cerebrovascular pathology in CD may help adequate prevention and early management of neurological involvement.

Preserved central cholinergic functioning to transcranial magnetic stimulation in de novo patients with celiac disease

BACKGROUND

Celiac disease (CD) is now viewed as a systemic disease with multifaceted clinical manifestations. Among the extra-intestinal features, neurological and neuropsychiatric symptoms are still a diagnostic challenge, since they can precede or follow the diagnosis of CD. In particular, it is well known that some adults with CD may complain of cognitive symptoms, that improve when the gluten-free diet (GFD) is started, although they may re-appear after incidental gluten intake. Among the neurophysiological techniques, motor evoked potentials (MEPs) to transcranial magnetic stimulation (TMS) can non-invasively probe in vivo the excitation state of cortical areas and cortico-spinal conductivity, being also able to unveil preclinical impairment in several neurological and psychiatric disorders, as well as in some systemic diseases affecting the central nervous system (CNS), such as CD. We previously demonstrated an intracortical disinhibition and hyperfacilitation of MEP responses to TMS in newly diagnosed patients. However, no data are available on the central cholinergic functioning indexed by specific TMS measures, such as the short-latency afferent inhibition (SAI), which might represent the neurophysiological correlate of cognitive changes in CD patients, also at the preclinical level.

METHODS

Cognitive and depressive symptoms were screened by means of the Montreal Cognitive Assessment (MoCA) and the 17-item Hamilton Depression Rating Scale (HDRS), respectively, in 15 consecutive de novo CD patients and 15 healthy controls. All patients were on normal diet at the time of the enrolment. Brain computed tomography (CT) was performed in all patients. SAI, recorded at two interstimulus intervals (2 and 8 ms), was assessed as the percentage amplitude ratio between the conditioned and the unconditioned MEP response. Resting motor threshold, MEP amplitude and latency, and central motor conduction time were also measured.

RESULTS

The two groups were comparable for age, sex, anthropometric features, and educational level. Brain CT ruled out intracranial calcifications and clear radiological abnormalities in all patients. Scores at MoCA and HDRS were significantly worse in patients than in controls. The comparison of TMS data between the two groups revealed no statistically significant difference for all measures, including SAI at both interstimulus intervals.

CONCLUSIONS

Central cholinergic functioning explored by the SAI of the motor cortex resulted to be not affected in these de novo CD patients compared to age-matched healthy controls. Although the statistically significant difference in MoCA, an overt cognitive impairment was not clinically evident in CD patients. Coherently, to date, no study based on TMS or other diagnostic techniques has shown any involvement of the central acetylcholine or the cholinergic fibers within the CNS in CD. This finding might add support to the vascular inflammation hypothesis underlying the so-called "gluten encephalopathy", which seems to be due to an aetiology different from that of the cholinergic dysfunction. Longitudinal studies correlating clinical, TMS, and neuroimaging data, both before and after GFD, are needed.

Intracortical and Intercortical Motor Disinhibition to Transcranial Magnetic Stimulation in Newly Diagnosed Celiac Disease Patients

BACKGROUND

Celiac disease (CD) may present or be complicated by neurological and neuropsychiatric manifestations. Transcranial magnetic stimulation (TMS) probes brain excitability non-invasively, also preclinically. We previously demonstrated an intracortical motor disinhibition and hyperfacilitation in de novo CD patients, which revert back after a long-term gluten-free diet (GFD). In this cross-sectional study, we explored the interhemispheric excitability by transcallosal inhibition, which has never been investigated in CD.

METHODS

A total of 15 right-handed de novo, neurologically asymptomatic, CD patients and 15 age-matched healthy controls were screened for cognitive and depressive symptoms to the Montreal Cognitive Assessment (MoCA) and the 17-item Hamilton Depression Rating Scale (HDRS), respectively. TMS consisted of resting motor threshold, amplitude, latency, and duration of the motor evoked potentials, duration and latency of the contralateral silent period (cSP). Transcallosal inhibition was evaluated as duration and latency of the ipsilateral silent period (iSP).

RESULTS

MoCA and HDRS scored significantly worse in patients. The iSP and cSP were significantly shorter in duration in patients, with a positive correlation between the MoCA and iSP.

CONCLUSIONS

An intracortical and interhemispheric motor disinhibition was observed in CD, suggesting the involvement of GABA-mediated cortical and callosal circuitries. Further studies correlating clinical, TMS, and neuroimaging data are needed.

Intracortical and Intercortical Motor Disinhibition to Transcranial Magnetic Stimulation in Newly Diagnosed Celiac Disease Patients

BACKGROUND

Celiac disease (CD) may present or be complicated by neurological and neuropsychiatric manifestations. Transcranial magnetic stimulation (TMS) probes brain excitability non-invasively, also preclinically. We previously demonstrated an intracortical motor disinhibition and hyperfacilitation in de novo CD patients, which revert back after a long-term gluten-free diet (GFD). In this cross-sectional study, we explored the interhemispheric excitability by transcallosal inhibition, which has never been investigated in CD.

METHODS

A total of 15 right-handed de novo, neurologically asymptomatic, CD patients and 15 age-matched healthy controls were screened for cognitive and depressive symptoms to the Montreal Cognitive Assessment (MoCA) and the 17-item Hamilton Depression Rating Scale (HDRS), respectively. TMS consisted of resting motor threshold, amplitude, latency, and duration of the motor evoked potentials, duration and latency of the contralateral silent period (cSP). Transcallosal inhibition was evaluated as duration and latency of the ipsilateral silent period (iSP).

RESULTS

MoCA and HDRS scored significantly worse in patients. The iSP and cSP were significantly shorter in duration in patients, with a positive correlation between the MoCA and iSP.

CONCLUSIONS

An intracortical and interhemispheric motor disinhibition was observed in CD, suggesting the involvement of GABA-mediated cortical and callosal circuitries. Further studies correlating clinical, TMS, and neuroimaging data are needed.

Preserved central cholinergic functioning to transcranial magnetic stimulation in de novo patients with celiac disease

BACKGROUND

Celiac disease (CD) is now viewed as a systemic disease with multifaceted clinical manifestations. Among the extra-intestinal features, neurological and neuropsychiatric symptoms are still a diagnostic challenge, since they can precede or follow the diagnosis of CD. In particular, it is well known that some adults with CD may complain of cognitive symptoms, that improve when the gluten-free diet (GFD) is started, although they may re-appear after incidental gluten intake. Among the neurophysiological techniques, motor evoked potentials (MEPs) to transcranial magnetic stimulation (TMS) can non-invasively probe in vivo the excitation state of cortical areas and cortico-spinal conductivity, being also able to unveil preclinical impairment in several neurological and psychiatric disorders, as well as in some systemic diseases affecting the central nervous system (CNS), such as CD. We previously demonstrated an intracortical disinhibition and hyperfacilitation of MEP responses to TMS in newly diagnosed patients. However, no data are available on the central cholinergic functioning indexed by specific TMS measures, such as the short-latency afferent inhibition (SAI), which might represent the neurophysiological correlate of cognitive changes in CD patients, also at the preclinical level.

METHODS

Cognitive and depressive symptoms were screened by means of the Montreal Cognitive Assessment (MoCA) and the 17-item Hamilton Depression Rating Scale (HDRS), respectively, in 15 consecutive de novo CD patients and 15 healthy controls. All patients were on normal diet at the time of the enrolment. Brain computed tomography (CT) was performed in all patients. SAI, recorded at two interstimulus intervals (2 and 8 ms), was assessed as the percentage amplitude ratio between the conditioned and the unconditioned MEP response. Resting motor threshold, MEP amplitude and latency, and central motor conduction time were also measured.

RESULTS

The two groups were comparable for age, sex, anthropometric features, and educational level. Brain CT ruled out intracranial calcifications and clear radiological abnormalities in all patients. Scores at MoCA and HDRS were significantly worse in patients than in controls. The comparison of TMS data between the two groups revealed no statistically significant difference for all measures, including SAI at both interstimulus intervals.

CONCLUSIONS

Central cholinergic functioning explored by the SAI of the motor cortex resulted to be not affected in these de novo CD patients compared to age-matched healthy controls. Although the statistically significant difference in MoCA, an overt cognitive impairment was not clinically evident in CD patients. Coherently, to date, no study based on TMS or other diagnostic techniques has shown any involvement of the central acetylcholine or the cholinergic fibers within the CNS in CD. This finding might add support to the vascular inflammation hypothesis underlying the so-called "gluten encephalopathy", which seems to be due to an aetiology different from that of the cholinergic dysfunction. Longitudinal studies correlating clinical, TMS, and neuroimaging data, both before and after GFD, are needed.

A Distinct EEG Marker of Celiac Disease-Related Cortical Myoclonus

BACKGROUND

Celiac disease is associated with motor cortex hyperexcitability and neurological manifestations including cortical myoclonus. Electroencephalography abnormalities have been described, but no distinct pattern has been reported.

METHODS

We describe the neurophysiological characteristics of 3 patients with celiac-associated cortical myoclonus using electroencephalography, magnetoencephalography, and transcranial magnetic stimulation.

RESULTS

Electroencephalography in all cases demonstrated lateralized low-amplitude, electropositive beta-frequency polyspike activity over the central head region, corresponding to motor cortex contralateral to the myoclonic limb. Jerk-locked back-averaging demonstrated a preceding cortical potential; magnetoencephalography source localization revealed a cortical generator in the posterior wall of the precentral gyrus for the back-averaged potential and oscillatory abnormality. In 1 patient, cerebellar inhibition of the motor cortex was physiologically normal.

CONCLUSIONS

Central head oscillatory, low-amplitude, electropositive electroencephalography polyspike activity may be a distinct marker of celiac-related cortical myoclonus and is consistent with celiac-related motor cortex hyperexcitability, which may not necessarily result from cerebellar disinhibition. © 2020 International Parkinson and Movement Disorder Society.

TMS Correlates of Pyramidal Tract Signs and Clinical Motor Status in Patients with Cervical Spondylotic Myelopathy

BACKGROUND

While the association between motor-evoked potential (MEP) abnormalities and motor deficit is well established, few studies have reported the correlation between MEPs and signs of pyramidal tract dysfunction without motor weakness. We assessed MEPs in patients with pyramidal signs, including motor deficits, compared to patients with pyramidal signs but without weakness.

METHODS

Forty-three patients with cervical spondylotic myelopathy (CSM) were dichotomized into 21 with pyramidal signs including motor deficit (Group 1) and 22 with pyramidal signs and normal strength (Group 2), and both groups were compared to 33 healthy controls (Group 0). MEPs were bilaterally recorded from the first dorsal interosseous and tibialis anterior muscle. The central motor conduction time (CMCT) was estimated as the difference between MEP latency and peripheral latency by magnetic stimulation. Peak-to-peak MEP amplitude and right-to-left differences were also measured.

RESULTS

Participants were age-, sex-, and height-matched. MEP latency in four limbs and CMCT in the lower limbs were prolonged, and MEP amplitude in the lower limbs decreased in Group 1 compared to the others. Unlike motor deficit, pyramidal signs were not associated with MEP measures, even when considering age, sex, and height as confounding factors.

CONCLUSIONS

In CSM, isolated pyramidal signs may not be associated, at this stage, with MEP changes.

TMS Correlates of Pyramidal Tract Signs and Clinical Motor Status in Patients with Cervical Spondylotic Myelopathy

BACKGROUND

While the association between motor-evoked potential (MEP) abnormalities and motor deficit is well established, few studies have reported the correlation between MEPs and signs of pyramidal tract dysfunction without motor weakness. We assessed MEPs in patients with pyramidal signs, including motor deficits, compared to patients with pyramidal signs but without weakness.

METHODS

Forty-three patients with cervical spondylotic myelopathy (CSM) were dichotomized into 21 with pyramidal signs including motor deficit (Group 1) and 22 with pyramidal signs and normal strength (Group 2), and both groups were compared to 33 healthy controls (Group 0). MEPs were bilaterally recorded from the first dorsal interosseous and tibialis anterior muscle. The central motor conduction time (CMCT) was estimated as the difference between MEP latency and peripheral latency by magnetic stimulation. Peak-to-peak MEP amplitude and right-to-left differences were also measured.

RESULTS

Participants were age-, sex-, and height-matched. MEP latency in four limbs and CMCT in the lower limbs were prolonged, and MEP amplitude in the lower limbs decreased in Group 1 compared to the others. Unlike motor deficit, pyramidal signs were not associated with MEP measures, even when considering age, sex, and height as confounding factors.

CONCLUSIONS

In CSM, isolated pyramidal signs may not be associated, at this stage, with MEP changes.

Child and Parent Mental Health Problems in Pediatric Celiac Disease: A Prospective Study

OBJECTIVES

The aim of our study was to estimate the levels of mental health problems in children with celiac disease (CD) along with their parents' mental health status, to compare these levels with those of healthy controls and to investigate how these problems are affected by a gluten-free diet (GFD).

METHODS

Our study constituted 50 patients with CD at diagnosis before the initiation of a GFD (age 8.6 ± 3.7 years, group A), 39 patients with CD on a GFD for at least 12 months (age 10.4 ± 3.4 years, group B) and 38 healthy controls (age 7.7 ± 3.8 years, group C), as well as their parents. One of the parents of each child completed the Child Behaviour Checklist (CBCL) and the Symptom Checklist 90 (SCL-90-R) to evaluate the children's and parents' mental health problems, respectively. Twenty patients in group A were reevaluated at least 12 months after initiation of a GFD (group D).

RESULTS

At diagnosis, CD patients had higher scores in the CBCL for internalizing problems than healthy controls (55.7 ± 10.3 vs 47.9 ± 15.4, P = 0.007) and their parents demonstrated increased severity of mental health problems, including anxiety and depression, than the parents of healthy controls (0.72 ± 0.49 vs 0.54 ± 0.58, P = 0.013).

CONCLUSIONS

CD patients at diagnosis and their parents, had more mental health problems, including anxiety and depression, than healthy controls.

Motor activity and Becker's muscular dystrophy: lights and shadows

Becker's disease is an inherited muscular dystrophy caused by mutations in the gene coding for the dystrophin protein that leads to quantitative and/or qualitative protein dysfunction and consequent muscle degeneration. Studies in animal models demonstrate that, while eccentric or high-intensity training are deleterious for dystrophic muscles, low-intensity aerobic training may slowdown the disease process and progression. Based on these preclinical data, the available studies in patients with Becker's muscular dystrophy undergoing workout on a cycle ergometer or on a treadmill, at a heart rate ≤65% of their maximal oxygen uptake, showed that aerobic exercise counteracts physical deterioration and loss of functional abilities. These findings suggest an improvement of physical performance through an increase of muscle strength, fatigue resistance, and dexterity capacities, without substantial evidence of acceleration of muscular damage progression. Therefore, individually tailored mild-to-moderate intensity aerobic exercise should be considered as part of the management of these patients. However, further research is necessary to define specific and standardized guidelines for the prescription of type, intensity, frequency, and duration of motor activities. In this review, we provided a summary of the impact of physical activity both in animal models and in patients with Becker's muscular dystrophy, with the intent to identify trends and gaps in knowledge. The potential therapeutic implications and future research directions have been also highlighted.

Update on the Neurobiology of Vascular Cognitive Impairment: From Lab to Clinic

In the last years, there has been a significant growth in the literature exploring the pathophysiology of vascular cognitive impairment (VCI). As an "umbrella term" encompassing any degree of vascular-related cognitive decline, VCI is deemed to be the most common cognitive disorder in the elderly, with a significant impact on social and healthcare expenses. Interestingly, some of the molecular, biochemical, and electrophysiological abnormalities detected in VCI seem to correlate with disease process and progression, eventually promoting an adaptive plasticity in some patients and a maladaptive, dysfunctional response in others. However, the exact relationships between vascular lesion, cognition, and neuroplasticity are not completely understood. Recent findings point out also the possibility to identify a panel of markers able to predict cognitive deterioration in the so-called "brain at risk" for vascular or mixed dementia. This will be of pivotal importance when designing trials of disease-modifying drugs or non-pharmacological approaches, including non-invasive neuromodulatory techniques. Taken together, these advances could make VCI a potentially preventable cause of both vascular and degenerative dementia in late life. This review provides a timely update on the recent serological, cerebrospinal fluid, histopathological, imaging, and neurophysiological studies on this "cutting-edge" topic, including the limitations, future perspectives and translational implications in the diagnosis and management of VCI patients.

Update on the Neurobiology of Vascular Cognitive Impairment: From Lab to Clinic

In the last years, there has been a significant growth in the literature exploring the pathophysiology of vascular cognitive impairment (VCI). As an "umbrella term" encompassing any degree of vascular-related cognitive decline, VCI is deemed to be the most common cognitive disorder in the elderly, with a significant impact on social and healthcare expenses. Interestingly, some of the molecular, biochemical, and electrophysiological abnormalities detected in VCI seem to correlate with disease process and progression, eventually promoting an adaptive plasticity in some patients and a maladaptive, dysfunctional response in others. However, the exact relationships between vascular lesion, cognition, and neuroplasticity are not completely understood. Recent findings point out also the possibility to identify a panel of markers able to predict cognitive deterioration in the so-called "brain at risk" for vascular or mixed dementia. This will be of pivotal importance when designing trials of disease-modifying drugs or non-pharmacological approaches, including non-invasive neuromodulatory techniques. Taken together, these advances could make VCI a potentially preventable cause of both vascular and degenerative dementia in late life. This review provides a timely update on the recent serological, cerebrospinal fluid, histopathological, imaging, and neurophysiological studies on this "cutting-edge" topic, including the limitations, future perspectives and translational implications in the diagnosis and management of VCI patients.

Facilitatory/inhibitory intracortical imbalance in REM sleep behavior disorder: early electrophysiological marker of neurodegeneration?

STUDY OBJECTIVES

Previous studies found an early impairment of the short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF) to transcranial magnetic stimulation (TMS) in Parkinson's disease. However, very little is known on the TMS correlates of rapid eye movement (REM) sleep behavior disorder (RBD), which can precede the onset of a α-synucleinopathy.

METHODS

The following TMS measures were obtained from 14 de novo patients with isolated RBD and 14 age-matched healthy controls: resting motor threshold, cortical silent period, latency and amplitude of the motor evoked potentials, SICI, and ICF. A cognitive screening and a quantification of subjective sleepiness (Epworth Sleepiness Scale [ESS]) and depressive symptoms were also performed.

RESULTS

Neurological examination, global cognitive functioning, and mood status were normal in all participants. ESS score was higher in patients, although not suggestive of diurnal sleepiness. Compared to controls, patients exhibited a significant decrease of ICF (median 0.8, range 0.5-1.4 vs. 1.9, range 1.4-2.3; p < 0.01) and a clear trend, though not significant, towards a reduction of SICI (median 0.55, range 0.1-1.4 vs. 0.25, range 0.1-0.3), with a large effect size (Cohen's d: -0.848). REM Sleep Atonia Index significantly correlated with SICI.

CONCLUSIONS

In still asymptomatic patients for a parkinsonian syndrome or neurodegenerative disorder, changes of ICF and, to a lesser extent, SICI (which are largely mediated by glutamatergic and GABAergic transmission, respectively) might precede the onset of a future neurodegeneration. SICI was correlated with the muscle tone alteration, possibly supporting the proposed RBD model of retrograde influence on the cortex from the brainstem.

Association of oral dysbiosis with oral cancer development

Oral squamous cell carcinoma (OSCC) is the leading cause of mortality for oral cancer. Numerous risk factors mainly related to unhealthy habits and responsible for chronic inflammation and infections have been recognized as predisposing factors for oral carcinogenesis. Recently, even microbiota alterations have been associated with the development of human cancers. In particular, some specific bacterial strains have been recognized and strongly associated with oral cancer development (Capnocytophaga gingivalis, Fusobacterium spp., Streptococcus spp., Peptostreptococcus spp., Porphyromonas gingivalis and Prevotella spp.). Several hypotheses have been proposed to explain how the oral microbiota could be involved in cancer pathogenesis by mainly paying attention to chronic inflammation, microbial synthesis of cancerogenic substances, and alteration of epithelial barrier integrity. Based on knowledge of the carcinogenic effects of dysbiosis, it was recently suggested that probiotics may have anti-tumoral activity. Nevertheless, few data exist with regard to probiotic effects on oral cancer. On this basis, the association between the development of oral cancer and oral dysbiosis is discussed focusing attention on the potential benefits of probiotics administration in cancer prevention.

Update on intensive motor training in spinocerebellar ataxia: time to move a step forward?

Some evidence suggests that high-intensity motor training slows down the severity of spinocerebellar ataxia. However, whether all patients might benefit from these activities, and by which activity, and the underlying mechanisms remain unclear. We provide an update on the effect and limitations of different training programmes in patients with spinocerebellar ataxias. Overall, data converge of the finding that intensive training is still based either on conventional rehabilitation protocols or whole-body controlled videogames ("exergames"). Notwithstanding the limitations, short-term improvement is observed, which tends to be lost once the training is stopped. Exergames and virtual reality can ameliorate balance, coordination, and walking abilities, whereas the efficacy of adapted physical activity, gym, and postural exercises depends on the disease duration and severity. In conclusion, although a disease-modifying effect has not been demonstrated, constant, individually tailored, high-intensity motor training might be effective in patients with degenerative ataxia, even in those with severe disease. These approaches may enhance the remaining cerebellar circuitries or plastically induce compensatory networks. Further research is required to identify predictors of training success, such as the type and severity of ataxia and the level of residual functioning.

Principles of Electrophysiological Assessments for Movement Disorders

Electrophysiological studies can provide objective and quantifiable assessments of movement disorders. They are useful in the diagnosis of hyperkinetic movement disorders, particularly tremors and myoclonus. The most commonly used measures are surface electromyography (sEMG), electroencephalography (EEG) and accelerometry. Frequency and coherence analyses of sEMG signals may reveal the nature of tremors and the source of the tremors. The effects of voluntary tapping, ballistic movements and weighting of the limbs can help to distinguish between organic and functional tremors. The presence of Bereitschafts-potentials and beta-band desynchronization recorded by EEG before movement onset provide strong evidence for functional movement disorders. EMG burst durations, distributions and muscle recruitment orders may identify and classify myoclonus to cortical, subcortical or spinal origins and help in the diagnosis of functional myoclonus. Organic and functional cervical dystonia can potentially be distinguished by EMG power spectral analysis. Several reflex circuits, such as the long latency reflex, blink reflex and startle reflex, can be elicited with different types of external stimuli and are useful in the assessment of myoclonus, excessive startle and stiff person syndrome. However, limitations of the tests should be recognized, and the results should be interpreted together with clinical observations.

Migrainous Infarction And Cerebral Vasospasm: Case Report And Literature Review

Migrainous infarction (MI) is a rare complication of migraines that accounts for 0.5-1.5% of all ischemic strokes. Although the pathogenesis of MI is still debated, cortical spreading depression and the consequent biochemical cascade and hemodynamic changes are presumed to play an important role. Here we describe a case of MI and systematically review the literature on the complex and possibly bidirectional relationship between migraine and stroke. A 44-year-old female with history of migraine with visual aura presented at the Emergency Department due to a sudden onset of left limb paresis and hypoesthesia. Brain magnetic resonance imaging revealed right fronto-parietal ischemic stroke. Two days after hospitalization, the patient experienced a prolonged visual aura and showed ultrasound evidence of intracranial artery vasospasm. To date, there have been 33 published articles on a total 119 patients with MI, although intracranial vasospasm has rarely been reported. Sustained hyperexcitability of cortical neurons, impairment of γ-aminobutyric acid inhibitory circuitry, altered serotonergic transmission, release of vasoconstrictive molecules, and cerebral blood flow changes have been proposed as pathogenic mechanisms of MI. The present case provides insight into the pathophysiological link between stroke and migraine, thus aiding clinicians in therapeutic decision-making although additional studies are needed to clarify the clinical, neuroradiological, and ultrasound findings that link MI and stroke-related migraine.

Repetitive transcranial magnetic stimulation in stroke rehabilitation: review of the current evidence and pitfalls

Acute brain ischemia causes changes in several neural networks and related cortico-subcortical excitability, both in the affected area and in the apparently spared contralateral hemisphere. The modulation of these processes through modern techniques of noninvasive brain stimulation, namely repetitive transcranial magnetic stimulation (rTMS), has been proposed as a viable intervention that could promote post-stroke clinical recovery and functional independence. This review provides a comprehensive summary of the current evidence from the literature on the efficacy of rTMS applied to different clinical and rehabilitative aspects of stroke patients. A total of 32 meta-analyses published until July 2019 were selected, focusing on the effects on motor function, manual dexterity, walking and balance, spasticity, dysphagia, aphasia, unilateral neglect, depression, and cognitive function after a stroke. Only conventional rTMS protocols were considered in this review, and meta-analyses focusing on theta burst stimulation only were excluded. Overall, both HF-rTMS and LF-rTMS have been shown to be safe and well-tolerated. In addition, the current literature converges on the positive effect of rTMS in the rehabilitation of all clinical manifestations of stroke, except for spasticity and cognitive impairment, where definitive evidence of efficacy cannot be drawn. However, routine use of a specific paradigm of stimulation cannot be recommended yet due to a significant level of heterogeneity of the studies in terms of protocols to be set and outcome measures that have to be used. Future studies need to preliminarily evaluate the most promising protocols before going on to multicenter studies with large cohorts of patients in order to achieve a definitive translation into daily clinical practice.

Repetitive transcranial magnetic stimulation in stroke rehabilitation: review of the current evidence and pitfalls

Acute brain ischemia causes changes in several neural networks and related cortico-subcortical excitability, both in the affected area and in the apparently spared contralateral hemisphere. The modulation of these processes through modern techniques of noninvasive brain stimulation, namely repetitive transcranial magnetic stimulation (rTMS), has been proposed as a viable intervention that could promote post-stroke clinical recovery and functional independence. This review provides a comprehensive summary of the current evidence from the literature on the efficacy of rTMS applied to different clinical and rehabilitative aspects of stroke patients. A total of 32 meta-analyses published until July 2019 were selected, focusing on the effects on motor function, manual dexterity, walking and balance, spasticity, dysphagia, aphasia, unilateral neglect, depression, and cognitive function after a stroke. Only conventional rTMS protocols were considered in this review, and meta-analyses focusing on theta burst stimulation only were excluded. Overall, both HF-rTMS and LF-rTMS have been shown to be safe and well-tolerated. In addition, the current literature converges on the positive effect of rTMS in the rehabilitation of all clinical manifestations of stroke, except for spasticity and cognitive impairment, where definitive evidence of efficacy cannot be drawn. However, routine use of a specific paradigm of stimulation cannot be recommended yet due to a significant level of heterogeneity of the studies in terms of protocols to be set and outcome measures that have to be used. Future studies need to preliminarily evaluate the most promising protocols before going on to multicenter studies with large cohorts of patients in order to achieve a definitive translation into daily clinical practice.

Update on intensive motor training in spinocerebellar ataxia: time to move a step forward?

Some evidence suggests that high-intensity motor training slows down the severity of spinocerebellar ataxia. However, whether all patients might benefit from these activities, and by which activity, and the underlying mechanisms remain unclear. We provide an update on the effect and limitations of different training programmes in patients with spinocerebellar ataxias. Overall, data converge of the finding that intensive training is still based either on conventional rehabilitation protocols or whole-body controlled videogames ("exergames"). Notwithstanding the limitations, short-term improvement is observed, which tends to be lost once the training is stopped. Exergames and virtual reality can ameliorate balance, coordination, and walking abilities, whereas the efficacy of adapted physical activity, gym, and postural exercises depends on the disease duration and severity. In conclusion, although a disease-modifying effect has not been demonstrated, constant, individually tailored, high-intensity motor training might be effective in patients with degenerative ataxia, even in those with severe disease. These approaches may enhance the remaining cerebellar circuitries or plastically induce compensatory networks. Further research is required to identify predictors of training success, such as the type and severity of ataxia and the level of residual functioning.

Adjunct Diagnostic Value of Transcranial Magnetic Stimulation in Mucopolysaccharidosis-Related Cervical Myelopathy: A Pilot Study

BACKGROUND

Cervical myelopathy (CM) is a common cause of morbidity and disability in patients with mucopolysaccharidosis (MPS) and, therefore, early detection is crucial for the best surgical intervention and follow-up. Transcranial magnetic stimulation (TMS) non-invasively evaluates the conduction through the cortico-spinal tract, also allowing preclinical diagnosis and monitoring.

METHODS

Motor evoked potentials (MEPs) to TMS were recorded in a group of eight patients with MPS-related CM. Responses were obtained during mild tonic muscular activation by means of a circular coil held on the "hot spot" of the first dorsal interosseous and tibialis anterior muscles, bilaterally. The motor latency by cervical or lumbar magnetic stimulation was subtracted from the MEP cortical latency to obtain the central motor conduction time. The MEP amplitude from peak to peak to cortical stimulation and the interside difference of each measure were also calculated.

RESULTS

TMS revealed abnormal findings from both upper and lower limbs compatible with axonal damage and demyelination in six of them. Notably, a subclinical cervical spinal disease was detected before the occurrence of an overt CM in two patients, whereas TMS signs compatible with a CM of variable degree persisted despite surgery in all treated subjects.

CONCLUSIONS

TMS can be viewed as an adjunct diagnostic test pending further rigorous investigations.

Adjunct Diagnostic Value of Transcranial Magnetic Stimulation in Mucopolysaccharidosis-Related Cervical Myelopathy: A Pilot Study

BACKGROUND

Cervical myelopathy (CM) is a common cause of morbidity and disability in patients with mucopolysaccharidosis (MPS) and, therefore, early detection is crucial for the best surgical intervention and follow-up. Transcranial magnetic stimulation (TMS) non-invasively evaluates the conduction through the cortico-spinal tract, also allowing preclinical diagnosis and monitoring.

METHODS

Motor evoked potentials (MEPs) to TMS were recorded in a group of eight patients with MPS-related CM. Responses were obtained during mild tonic muscular activation by means of a circular coil held on the "hot spot" of the first dorsal interosseous and tibialis anterior muscles, bilaterally. The motor latency by cervical or lumbar magnetic stimulation was subtracted from the MEP cortical latency to obtain the central motor conduction time. The MEP amplitude from peak to peak to cortical stimulation and the interside difference of each measure were also calculated.

RESULTS

TMS revealed abnormal findings from both upper and lower limbs compatible with axonal damage and demyelination in six of them. Notably, a subclinical cervical spinal disease was detected before the occurrence of an overt CM in two patients, whereas TMS signs compatible with a CM of variable degree persisted despite surgery in all treated subjects.

CONCLUSIONS

TMS can be viewed as an adjunct diagnostic test pending further rigorous investigations.

The analysis of miRNA expression profiling datasets reveals inverse microRNA patterns in glioblastoma and Alzheimer's disease

There is recent evidence to indicate the existence of an inverse association between the incidence of neurological disorders and cancer development. Concurrently, the transcriptional pathways responsible for the onset of glioblastoma multiforme (GBM) and Alzheimer's disease (AD) have been found to be mutually exclusive between the two pathologies. Despite advancements being made concerning the knowledge of the molecular mechanisms responsible for the development of GBM and AD, little is known about the identity of the microRNA (miRNAs or miRs) involved in the development and progression of these two pathologies and their possible inverse expression patterns. On these bases, the aim of the present study was to identify a set of miRNAs significantly de-regulated in both GBM and AD, and hence to determine whether the identified miRNAs exhibit an inverse association within the two pathologies. For this purpose, miRNA expression profiling datasets derived from the Gene Expression Omnibus (GEO) DataSets and relative to GBM and AD were used. Once the miRNAs significantly de-regulated in both pathologies were identified, DIANA-mirPath pathway prediction and STRING Gene Ontology enrichment analyses were performed to establish their functional roles in each of the pathologies. The results allowed the identification of a set of miRNAs found de-regulated in both GBM and AD, whose expression levels were inversely associated in the two pathologies. In particular, a strong negative association was observed between the expression levels of miRNAs in GBM compared to AD, suggesting that although the molecular pathways behind the development of these two pathologies are the same, they appear to be inversely regulated by miRNAs. Despite the identification of this set of miRNAs which may be used for diagnostic, prognostic and therapeutic purposes, further functional in vitro and in vivo evaluations are warranted in order to validate the diagnostic and therapeutic potential of the identified miRNAs, as well as their involvement in the development of GBM and AD.

Age, Height, and Sex on Motor Evoked Potentials: Translational Data From a Large Italian Cohort in a Clinical Environment

Introduction

Motor evoked potentials (MEPs) to transcranial magnetic stimulation (TMS) are known to be susceptible to several sources of variability. However, conflicting evidences on individual characteristics in relatively small sample sizes have been reported. We investigated the effect of age, height, and sex on MEPs of the motor cortex and spinal roots in a large cohort.

Methods

A total of 587 subjects clinically and neuroradiologically intact were included. MEPs were recorded during mild tonic contraction through a circular coil applied over the "hot spot" of the first dorsal interosseous and tibialis anterior muscles (TAs), bilaterally. Central motor conduction time (CMCT) was estimated as the difference between MEP cortical latency and the peripheral motor conduction time (PMCT) by cervical or lumbar magnetic stimulation. Peak-to-peak MEP amplitude to cortical stimulation and right-to-left difference of each parameter were also measured.

Results

After Bonferroni correction, general linear (multiple) regression analysis showed that both MEP cortical latency and PMCT at four limbs positively correlated with age and height. At lower limbs, an independent effect of sex on the same measures was also observed (with females showing smaller values than males). CMCT correlated with both age (negatively) and height (positively) when analyzed by a single regression; however, with a multiple regression analysis this significance disappeared, due to the correction for the multicollinearity within the dataset.

Conclusion

Physical individual features need to be considered for a more accurate and meaningful MEPs interpretation. Both in clinical practice and in research setting, patients and controls should be matched for age, height, and sex.

The Interactive Effect of Tonic Pain and Motor Learning on Corticospinal Excitability

Prior work showed differential alterations in early somatosensory evoked potentials (SEPs) and improved motor learning while in acute tonic pain. The aim of the current study was to determine the interactive effect of acute tonic pain and early motor learning on corticospinal excitability as measured by transcranial magnetic stimulation (TMS). Two groups of twelve participants (n = 24) were randomly assigned to a control (inert lotion) or capsaicin (capsaicin cream) group. TMS input–output (IO) curves were performed at baseline, post-application, and following motor learning acquisition. Following the application of the creams, participants in both groups completed a motor tracing task (pre-test and an acquisition test) followed by a retention test (completed without capsaicin) within 24–48 h. Following an acquisition phase, there was a significant increase in the slope of the TMS IO curves for the control group (p < 0.05), and no significant change for the capsaicin group (p = 0.57). Both groups improved in accuracy following an acquisition phase (p < 0.001). The capsaicin group outperformed the control group at pre-test (p < 0.005), following an acquisition phase (p < 0.005), and following a retention test (p < 0.005). When data was normalized to the pre-test values, the learning effects were similar for both groups post-acquisition and at retention (p < 0.005), with no interactive effect of group. The acute tonic pain in this study was shown to negate the increase in IO slope observed for the control group despite the fact that motor performance improved similarly to the control group following acquisition and retention. This study highlights the need to better understand the implications of neural changes accompanying early motor learning, particularly while in pain.

Effect of Paired Associative Stimulation on Corticomotor Excitability in Chronic Smokers

Chronic smoking has been shown to have deleterious effects on brain function and is an important risk factor for ischemic stroke. Reduced cortical excitability has been shown among chronic smokers compared with non-smokers to have a long-term effect and so far no study has assessed the effect of smoking on short-term motor learning. Paired associative stimulation (PAS) is a commonly used method for inducing changes in excitability of the motor cortex (M1) in a way that simulates short-term motor learning. This study employed PAS to investigate the effect of chronic cigarette smoking on plasticity of M1. Stimulator output required to elicit a motor-evoked potential (MEP) of approximately 1 mV was similar between the groups prior to PAS. MEP response to single pulse stimuli increased in the control group and remained above baseline level for at least 30 min after the intervention, but not in the smokers who showed no significant increase in MEP size. The silent period was similar between groups at all time points of the experiment. This study suggests that chronic smoking may have a negative effect on the response to PAS and infers that chronic smoking may have a deleterious effect on the adaptability of M1.

Migrainous Infarction And Cerebral Vasospasm: Case Report And Literature Review

Migrainous infarction (MI) is a rare complication of migraines that accounts for 0.5-1.5% of all ischemic strokes. Although the pathogenesis of MI is still debated, cortical spreading depression and the consequent biochemical cascade and hemodynamic changes are presumed to play an important role. Here we describe a case of MI and systematically review the literature on the complex and possibly bidirectional relationship between migraine and stroke. A 44-year-old female with history of migraine with visual aura presented at the Emergency Department due to a sudden onset of left limb paresis and hypoesthesia. Brain magnetic resonance imaging revealed right fronto-parietal ischemic stroke. Two days after hospitalization, the patient experienced a prolonged visual aura and showed ultrasound evidence of intracranial artery vasospasm. To date, there have been 33 published articles on a total 119 patients with MI, although intracranial vasospasm has rarely been reported. Sustained hyperexcitability of cortical neurons, impairment of γ-aminobutyric acid inhibitory circuitry, altered serotonergic transmission, release of vasoconstrictive molecules, and cerebral blood flow changes have been proposed as pathogenic mechanisms of MI. The present case provides insight into the pathophysiological link between stroke and migraine, thus aiding clinicians in therapeutic decision-making although additional studies are needed to clarify the clinical, neuroradiological, and ultrasound findings that link MI and stroke-related migraine.

Age, Height, and Sex on Motor Evoked Potentials: Translational Data From a Large Italian Cohort in a Clinical Environment

INTRODUCTION

Motor evoked potentials (MEPs) to transcranial magnetic stimulation (TMS) are known to be susceptible to several sources of variability. However, conflicting evidences on individual characteristics in relatively small sample sizes have been reported. We investigated the effect of age, height, and sex on MEPs of the motor cortex and spinal roots in a large cohort.

METHODS

A total of 587 subjects clinically and neuroradiologically intact were included. MEPs were recorded during mild tonic contraction through a circular coil applied over the "hot spot" of the first dorsal interosseous and tibialis anterior muscles (TAs), bilaterally. Central motor conduction time (CMCT) was estimated as the difference between MEP cortical latency and the peripheral motor conduction time (PMCT) by cervical or lumbar magnetic stimulation. Peak-to-peak MEP amplitude to cortical stimulation and right-to-left difference of each parameter were also measured.

RESULTS

After Bonferroni correction, general linear (multiple) regression analysis showed that both MEP cortical latency and PMCT at four limbs positively correlated with age and height. At lower limbs, an independent effect of sex on the same measures was also observed (with females showing smaller values than males). CMCT correlated with both age (negatively) and height (positively) when analyzed by a single regression; however, with a multiple regression analysis this significance disappeared, due to the correction for the multicollinearity within the dataset.

CONCLUSION

Physical individual features need to be considered for a more accurate and meaningful MEPs interpretation. Both in clinical practice and in research setting, patients and controls should be matched for age, height, and sex.

Brain Ageing, Cognition and Diet: A Review of the Emerging Roles of Food-Based Nootropics in Mitigating Age-related Memory Decline

BACKGROUND

Age-related cognitive decline has been suggested to result from an increase in the brain neuron loss, which is attributable to continued derangement of the brain's oxidant/ antioxidant balance. Increased oxidative stress and a concomitant decrease in the brain's antioxidant defense system have been associated with functional senescence and organismal ageing. However, nature has configured certain foods to be rich sources of nootropic agents, with research showing that increased consumption of such foods or food ingredients may be protective against ageing-related memory decline. This knowledge is becoming increasingly valuable in an era when the boundary that separates food from medicine is becoming blurred. In this review, we examine extant literature dealing with the impact of ageing on brain structure and function, with an emphasis on the roles of oxidative stress. Secondly, we review the benefits of food-based antioxidants with nootropic effects and/or food-based nootropic agents in mitigating memory decline; with a view to improving our understanding of likely mechanisms. We also highlight some of the limitations to the use of food-based nootropics and suggest ways in which they can be better employed in the clinical management of age-related cognitive decline.

CONCLUSION

While it is known that the human brain endures diverse insults in the process of ageing, food-based nootropics are likely to go a long way in mitigating the impacts of these insults. Further research is needed before we reach a point where food-based nootropics are routinely prescribed.

Cognitive Impairment and Celiac Disease: Is Transcranial Magnetic Stimulation a Trait d'Union between Gut and Brain?

Celiac disease is a systemic disorder with multifactorial pathogenesis and multifaceted symptomatology. In response to gluten exposure, a significant part of the general population produces antibodies that have been hypothesized to be deleterious to the brain. Among the well-known neurological manifestations, adult celiac patients often complain cognitive symptoms, ranging from the so-called "brain fog" till an overt dementia. Transcranial magnetic stimulation (TMS) is a non-invasive brain stimulation technique that can contribute to the assessment and monitoring of celiac patients, even in those without a clear neurological involvement. The studies here reviewed seem to converge on an impaired central motor conductivity and a "hyperexcitable celiac brain" to TMS, which partially reverts back after a long-term gluten restriction. Notably, a clear hyperexcitability is a stably reported feature of both degenerative and vascular dementia. Therefore, given its potential neuroprotective effect, the gluten-free diet should be introduced as early as possible, although the overall response of neurological symptoms (and cognition in particular) is still controversial. Identifying new and possibly modifiable risk factors may be of crucial importance for patients, clinicians, and researchers.

Cognitive Impairment and Celiac Disease: Is Transcranial Magnetic Stimulation a Trait d'Union between Gut and Brain?

Celiac disease is a systemic disorder with multifactorial pathogenesis and multifaceted symptomatology. In response to gluten exposure, a significant part of the general population produces antibodies that have been hypothesized to be deleterious to the brain. Among the well-known neurological manifestations, adult celiac patients often complain cognitive symptoms, ranging from the so-called "brain fog" till an overt dementia. Transcranial magnetic stimulation (TMS) is a non-invasive brain stimulation technique that can contribute to the assessment and monitoring of celiac patients, even in those without a clear neurological involvement. The studies here reviewed seem to converge on an impaired central motor conductivity and a "hyperexcitable celiac brain" to TMS, which partially reverts back after a long-term gluten restriction. Notably, a clear hyperexcitability is a stably reported feature of both degenerative and vascular dementia. Therefore, given its potential neuroprotective effect, the gluten-free diet should be introduced as early as possible, although the overall response of neurological symptoms (and cognition in particular) is still controversial. Identifying new and possibly modifiable risk factors may be of crucial importance for patients, clinicians, and researchers.

Impaired short-term plasticity in restless legs syndrome: a pilot rTMS study

BACKGROUND

Previous studies showed an impairment of the LTP-like plasticity to TMS in restless legs syndrome (RLS). Clinically, repetitive TMS (rTMS) was effective in alleviating the sensory-motor complaints of patients, although the effects induced by low-frequency (inhibitory) rTMS have not yet been investigated. An impaired LTD-like mechanism of cortical plasticity has been hypothesized, which we have directly assessed in this pilot study.

METHODS

Motor evoked potentials (MEPs) from the right first dorsal interosseus muscle were recorded at the stimulus intensity of 110% of the resting motor threshold (rMT) from 13 right-handed patients and ten age-matched right-handed healthy controls. Median peak-to-peak amplitudes were calculated in all participants at baseline (T₀), after the first train of a single evening session of low-frequency (1 Hz) rTMS over the left primary motor cortex (T₁), and after the whole rTMS procedure (T₂), which consists of 20 trains with 50 stimuli per train and intertrain interval of 30 s (1000 stimuli in total).

RESULTS

No differences were found for rMT and MEPs size between the two groups at T₀. Smaller MEPs amplitudes at both T₁ and T₂ were observed in all subjects, although this was significantly more pronounced in controls than in patients.

CONCLUSIONS

Compared to normal individuals, patients exhibited an impairment of the LTD-like mechanisms induced by inhibitory rTMS, thus adding support to the involvement of GABA in RLS pathophysiology. Although future studies with a larger population are needed, TMS is confirmed to be effective in noninvasive probing of the neurophysiology and neurochemistry of RLS.

Serum brain-derived neurotrophic factor in children with coeliac disease

BACKGROUND

Brain-derived neurotrophic factor (BDNF) is a neurotrophin that has a protective role in the nervous system and is involved in neural plasticity. It is abundant in the central nervous system, but is also expressed in the gastrointestinal tract. Coeliac disease (CD), characterised by intestinal inflammation, has some comorbidity with neurologic and mental disorders. The aim of this study was to evaluate circulating BDNF concentrations in patients with CD at diagnosis or on a gluten-free diet (GFD) for longer than 1 year and in healthy controls (HC).

MATERIALS AND METHODS

Fifty newly diagnosed patients with CD (aged 8.6 ± 3.7 years, 64.0% females), thirty-nine patients on GFD for longer than 1 year (aged 10.4 ± 3.4 years, 71.8% females) and 36 HC (aged 8 ± 1.7 years, 33.3% females) were included in the study. Along with anthropometric evaluation and standard blood chemistry, serum BDNF levels were measured by a specific immunoenzymatic assay.

RESULTS

Patients at diagnosis and on GFD had significantly higher BDNF levels (26 110 ± 8204 and 28 860 ± 7992 pg/mL), respectively, than HC (19 630 ± 8093 pg/mL, P < .001 for both CD groups). Patients on GFD had significantly higher BDNF levels than those at diagnosis (P = .02).

CONCLUSIONS

Serum BDNF concentrations were higher in patients with CD than in HC, regardless of their status of gluten consumption. This could be attributed either to a potential protective response to the inflammation of the intestine or to chronic stress.

Clinical and electrophysiological impact of repetitive low-frequency transcranial magnetic stimulation on the sensory-motor network in patients with restless legs syndrome

Background

Based on the hyperexcitability and disinhibition observed in patients with restless legs syndrome (RLS) following transcranial magnetic stimulation (TMS), we conducted a study with low-frequency repetitive TMS (rTMS) over the primary motor (M1) and somatosensory cortical areas (S1) in patients with RLS.

Methods

A total of 13 right-handed patients and 10 age-matched controls were studied using clinical scales and TMS. Measurements included resting motor threshold (rMT), motor-evoked potentials (MEPs), cortical silent period (CSP), and central motor conduction time (CMCT). A single evening session of rTMS (1 Hz, 20 trains, 50 stimuli each) was administered over the left M1, left S1, and sham stimulation over M1 in a random order. Clinical and TMS measures were repeated after each stimulation modality.

Results

Baseline CSP was shorter in patients than in controls and remained shorter in patients for both motor and somatosensory stimulation. The patients reported a subjective improvement of both initiating and maintaining sleep the night after the rTMS over S1. Patients exhibited a decrease in rMT after rTMS of S1 only, although the effect was smaller than in controls. MEP latency and CMCT changed only in controls after stimulation. Sham stimulation was without effect on the observed variables.

Conclusions

rTMS on S1-M1 connectivity alleviated the sensory-motor complaints of RLS patients. The TMS indexes of excitation and inhibition indicate an intracortical and corticospinal imbalance, mainly involving gamma-aminobutyric acid (GABA)ergic and glutamatergic circuitries, as well as an impairment of the short-term mechanisms of cortical plasticity. The rTMS-induced activation of the dorsal striatum with the consequent increase of dopamine release may have contributed to the clinical and neurophysiological outcome.

Clinical and electrophysiological impact of repetitive low-frequency transcranial magnetic stimulation on the sensory-motor network in patients with restless legs syndrome

BACKGROUND

Based on the hyperexcitability and disinhibition observed in patients with restless legs syndrome (RLS) following transcranial magnetic stimulation (TMS), we conducted a study with low-frequency repetitive TMS (rTMS) over the primary motor (M1) and somatosensory cortical areas (S1) in patients with RLS.

METHODS

A total of 13 right-handed patients and 10 age-matched controls were studied using clinical scales and TMS. Measurements included resting motor threshold (rMT), motor-evoked potentials (MEPs), cortical silent period (CSP), and central motor conduction time (CMCT). A single evening session of rTMS (1 Hz, 20 trains, 50 stimuli each) was administered over the left M1, left S1, and sham stimulation over M1 in a random order. Clinical and TMS measures were repeated after each stimulation modality.

RESULTS

Baseline CSP was shorter in patients than in controls and remained shorter in patients for both motor and somatosensory stimulation. The patients reported a subjective improvement of both initiating and maintaining sleep the night after the rTMS over S1. Patients exhibited a decrease in rMT after rTMS of S1 only, although the effect was smaller than in controls. MEP latency and CMCT changed only in controls after stimulation. Sham stimulation was without effect on the observed variables.

CONCLUSIONS

rTMS on S1-M1 connectivity alleviated the sensory-motor complaints of RLS patients. The TMS indexes of excitation and inhibition indicate an intracortical and corticospinal imbalance, mainly involving gamma-aminobutyric acid (GABA)ergic and glutamatergic circuitries, as well as an impairment of the short-term mechanisms of cortical plasticity. The rTMS-induced activation of the dorsal striatum with the consequent increase of dopamine release may have contributed to the clinical and neurophysiological outcome.

Clinical and electrophysiological impact of repetitive low-frequency transcranial magnetic stimulation on the sensory-motor network in patients with restless legs syndrome

BACKGROUND

Based on the hyperexcitability and disinhibition observed in patients with restless legs syndrome (RLS) following transcranial magnetic stimulation (TMS), we conducted a study with low-frequency repetitive TMS (rTMS) over the primary motor (M1) and somatosensory cortical areas (S1) in patients with RLS.

METHODS

A total of 13 right-handed patients and 10 age-matched controls were studied using clinical scales and TMS. Measurements included resting motor threshold (rMT), motor-evoked potentials (MEPs), cortical silent period (CSP), and central motor conduction time (CMCT). A single evening session of rTMS (1 Hz, 20 trains, 50 stimuli each) was administered over the left M1, left S1, and sham stimulation over M1 in a random order. Clinical and TMS measures were repeated after each stimulation modality.

RESULTS

Baseline CSP was shorter in patients than in controls and remained shorter in patients for both motor and somatosensory stimulation. The patients reported a subjective improvement of both initiating and maintaining sleep the night after the rTMS over S1. Patients exhibited a decrease in rMT after rTMS of S1 only, although the effect was smaller than in controls. MEP latency and CMCT changed only in controls after stimulation. Sham stimulation was without effect on the observed variables.

CONCLUSIONS

rTMS on S1-M1 connectivity alleviated the sensory-motor complaints of RLS patients. The TMS indexes of excitation and inhibition indicate an intracortical and corticospinal imbalance, mainly involving gamma-aminobutyric acid (GABA)ergic and glutamatergic circuitries, as well as an impairment of the short-term mechanisms of cortical plasticity. The rTMS-induced activation of the dorsal striatum with the consequent increase of dopamine release may have contributed to the clinical and neurophysiological outcome.