Frontal lobe syndromes

Association of severe hyposmia and frontal lobe dysfunction in patients with Parkinson's disease

BACKGROUNDS AND OBJECTIVES

Severe hyposmia (SH) is a prodromal symptom of dementia associated with Parkinson's disease (PD) caused by Lewy bodies deposited in the limbic regions that connect the frontal and temporal lobes. We aimed to clarify the association between hyposmia and frontal lobe dysfunction (FLD) among patients with PD.

METHODS

Patients with PD and Hoehn & Yahr stage 1-3 at on-periods without apparent dementia were screened. FLD was defined as a score of ≤14 on the Frontal Assessment Battery (FAB). SH was defined as an average recognition threshold >4 in the T&T Olfactometer. For each subscore, a recognition score of ≥4 was defined as SH. We examined whether SH and its subscores were associated with FLD and evaluated which FAB subscore might be lower in PD patients with SH using Poisson regression analysis with a robust variance estimator.

RESULTS

We included 189 patients (median age, 68 years; 107 [57 %] male). FLD was observed in 53 (28 %) patients. Multivariable analysis showed that SH (PR 1.789, 95 % confidence intervals (CI) 1.115-2.872, p = 0.016) was associated with FLD. Regarding odor domains, only SH for fruity smells was associated with FLD (PR 1.970, 95 % CI 1.306-2.972, p = 0.001). Patients with SH had a higher subscore only for FAB-1 (similarity [conceptualization], p = 0.030), indicating linguistically mediated executive dysfunction.

CONCLUSION

In patients with PD, SH is associated with FLD, especially with linguistically mediated executive dysfunction. Particularly, SH for fruity smells may be a sensitive indicator of FLD.

Neuropsychological profile of a patient with multiple sclerosis and psychiatric symptoms that masked and delayed the diagnosis. A case report using teleneuropsychology

Objective: Multiple sclerosis (MS) may include not only severe neurological signs and symptoms, but also cognitive and psychiatric disturbances. When psychiatric symptoms precede or are comorbid with MS, it poses a clinical challenge, because it may lead to a mistaken diagnosis of MS as a psychiatric disorder, delaying proper treatment. We describe the neuropsychological profile of a female patient with MS whose diagnosis was delayed due to neuropsychiatric symptoms. Method: A comprehensive analysis of the medical history and the results of a teleneuropsychological assessment of a 36-year-old Mexican woman with a diagnosis of relapsing--remitting MS (RRMS) was performed. Results: The patient indicates a long history of psychotic, anxious, and depressive features years before the first neurological symptom that led to MS going unnoticed for several years. Language, attentional, perceptual, motor, and learning skills were found to be preserved. Short-term memory and spatial orientation problems were identified, with decreased processing speed and executive dysfunction, including working memory and planning deficits. Conclusions: The patient has a non-typical presentation of neuropsychological alterations with cognitive and behavioral symptoms that resemble dorsolateral frontal lobe syndrome. This case study highlights the importance of considering MS in differential diagnosis of patients with psychiatric symptoms, even in the absence of obvious neurological signs.

Neurocognition and brain functional connectivity in a non-clinical population-based sample with psychotic experiences

We characterized the neurocognitive profile of communed-based individuals and unaffected siblings of patients with psychosis from Brazil reporting psychotic experiences (PEs). We also analyzed associations between PEs and the intra and inter-functional connectivity (FC) in the Default Mode Network (DMN), the Fronto-Parietal Network (FPN) and the Salience Network (SN) measured by functional magnetic resonance imaging. The combined sample of communed-based individuals and unaffected siblings of patients with psychosis comprised 417 (neurocognition) and 85 (FC) volunteers who were divided as having low (<75th percentile) and high (≥75th percentile) PEs (positive, negative, and depressive dimensions) assessed by the Community Assessment of Psychic Experiences. The neurocognitive profile and the estimated current brief intellectual quotient (IQ) were assessed using the digit symbol (processing speed), arithmetic (working memory), block design (visual learning) and information (verbal learning) subtests of Wechsler Adult Intelligence Scale-third edition. Logistic regression models were performed for neurocognitive analysis. For neuroimaging, we used the CONN toolbox to assess FC between the specified regions, and ROI-to-ROI analysis. In the combined sample, high PEs (all dimensions) were related to lower processing speed performance. High negative PEs were related to poor visual learning performance and lower IQ, while high depressive PEs were associated with poor working memory performance. Those with high negative PEs presented FPN hypoconnectivity between the right and left lateral prefrontal cortex. There were no associations between PEs and the DMN and SN FC. Brazilian individuals with high PEs showed neurocognitive impairments like those living in wealthier countries. Hypoconnectivity in the FPN in a community sample with high PEs is coherent with the hypothesis of functional dysconnectivity in schizophrenia.

Development of a generic version of the multiple errands test for severe acquired brain injuries

BACKGROUND

Impairment of executive functions is a frequent and disabling consequence of brain injury. In 1991, Shallice and Burgess elaborated the Multiple Errand Test (MET) to assess everyday troubles associated with this impairment.

OBJECTIVE

Our first aim was to create a generic version of MET (MET-G) readily adaptable to different settings and for retesting. The second aim was to validate the revised version to detect executive impairment in individuals with severe ABI.

METHODS

An inter-professional team of experts in neurorehabilitation created a revised version of MET. Twenty-one patients with sABI (severe Acquired Brain Injury) and a control group of 20 neurologically healthy subjects, took part in the testing of MET-G.

RESULTS

MET-G clearly distinguished people with sABI from healthy controls based on Total error score, task completion, and rule breaking. The test showed good inter-rater reliability and internal consistency.

CONCLUSIONS

The new, generic version of MET was able to differentiate adults with sABI from controls and proved to be a good tool for evaluating executive functions in these patients in daily-life contexts. Indications on how to adapt the test to different contexts and different scoring modalities are provided.

Automation at the service of the study of executive functions in preclinical models

Cognitive flexibility involves the capability to switch between different perspectives and implement novel strategies upon changed circumstances. The Wisconsin Card Sorting Test (in humans) and the Attentional Set-Shifting Task (ASST, in rodents) evaluate individual capability to acquire a reward-associated rule and subsequently disregard it in favour of a new one. Both tasks entail consecutive stages wherein subjects discriminate between: two stimuli of a given category (simple discrimination, SD); the stimuli of SD confounded by an irrelevant stimulus of a different category (compound discrimination, CD); different stimuli belonging to the SD category (intradimensional shift, IDS); and two stimuli of the confounding category (extradimensional shift, EDS). The ASST is labour intensive, not sufficiently standardised, and prone to experimental error. Here, we tested the validity of a new, commercially available, automated version of ASST (OPERON) in two independent experiments conducted in: different mouse strains (C57BL/6 and CD1 mice) to confirm their differential cognitive capabilities (Experiment 1); and an experimental model of chronic stress (administration of corticosterone in the drinking water; Experiment 2). In both experiments, OPERON confirmed the findings obtained through the manual version. Just as in Experiment 1 both versions captured the deficit of C57BL/6 mice on the reversal of the CD (CDR), so also in Experiment 2 they provided analogous evidence that corticosterone treated mice have a remarkable impairment in the IDS. Thus, OPERON capitalises upon automated phenotyping to overcome the limitation of the manual version of the ASST while providing comparable results.

Tourette syndrome and obsessive-compulsive disorder: A comprehensive review of structural alterations and neurological mechanisms

Currently, it is possible to study the pathogenesis of Tourette's syndrome (TS) in more detail, due to more advanced methods of neuroimaging. However, medical and surgical treatment options are limited by a lack of understanding of the nature of the disorder and its relationship to some psychiatric disorders, the most common of which is obsessive-compulsive disorder (OCD). It is believed that the origin of chronic tic disorders is based on an imbalance of excitatory and inhibitory influences in the Cortico-Striato-Thalamo-Cortical circuits (CSTC). The main CSTCs involved in the pathological process have been identified by studying structural and neurotransmitter disturbances in the interaction between the cortex and the basal ganglia. A neurotransmitter deficiency in CSTC has been demonstrated by immunohistochemical and genetic methods, but it is still not known whether it arises as a consequence of genetically determined disturbances of neuronal migration during ontogenesis or as a consequence of altered production of proteins involved in neurotransmitter production. The aim of this review is to describe current ideas about the comorbidity of TS with OCD, the involvement of CSTC in the pathogenesis of both disorders and the background of structural and neurotransmitter changes in CSTC that may serve as targets for drug and neuromodulatory treatments.

Persistent dysexecutive syndrome after pneumococcal meningitis complicated by recurrent ischemic strokes: A case report

BACKGROUND

Meningitis is a possible complication of pneumococcal infection concerning acute otitis media and sinusitis. It might compromise cognitive function, both for the infection itself and the vascular events that sometimes follow the acute phase.

CASE SUMMARY

Here we describe the case of a 32-year-old female patient admitted to the emergency room due to extensive pneumococcal meningitis as a consequence of sinus outbreak. She presented with extensive laminar ischemic damage in the acute phase, resulting in severe cognitive and behavioural impairment. Four years of follow-up, through neuropsychological assessments and neuroradiological investigations, demonstrated the presence of subsequent vascular events, 3 months and 2 years after onset.

CONCLUSION

The case is discussed in light of scientific knowledge of the long-term outcomes of this pathology in order to potentially improve diagnosis and promote better outcomes.

The effect of oral medications on fMRI brain activation: A randomized, double blind, controlled pilot trial of older women with overactive bladder

INTRODUCTION AND AIM

Observational studies have associated oral anticholinergic medications for overactive bladder (OAB) with cognitive impairment. This is the first pilot trial to compare the effects of two classes of OAB medications on brain activity in women. We evaluated the effect of anticholinergic versus non-anticholinergic (Non-Ach) interventions on regional brain activation during a cognitive task.

METHODS

Twelve cognitively normal women seeking OAB therapy were recruited to a randomized, double-blind, parallel, controlled pilot trial. Whole-brain regional activity at baseline and 29 ± 1 days postintervention was assessed with functional magnetic resonance imaging during a working memory task. Average activation strength by region was compared after anticholinergic, beta-3 agonist, or placebo. Two-way ANOVA compared effects of group and time on average activation strength in anticholinergic versus Non-Ach (beta-3 agonists or placebo) groups.

RESULTS

The mean (SD) age and body mass index of 12 women were 61 (7) years and 36 (7) kg/m². Baseline depression and learning scores differed in the anticholinergic group (n = 3) versus the Non-Ach group (n = 9). Right mamillary body activation postintervention was higher after Non-Ach exposure (F 4.9, p < 0.04). In the full sample of participants at follow-up, there was less activation of the right middle frontal gyrus (p = 0.02), superior frontal gyrus (p < 0.01), and supramarginal (p < 0.01) gyrus.

CONCLUSION

Activation strength in brain regions underlying working memory was lower over time, and recognition scores improved. A powered trial is needed to adequately evaluate for differential effects of OAB oral medications on regional brain activation.

Neural mechanisms underlying the processing of emotional stimuli in individuals with depression: An ALE meta-analysis study

Depression is the leading cause of physiological problems and suicide. Previous studies have indicated that individuals with depression show abnormal processing of both positive and negative emotional stimuli. However, the common and distinct patterns of brain activity during the processing of positive and negative emotional stimuli in individuals with depression remain controversial. The current meta-analysis study used the activation likelihood estimation method to investigate these issues across 21 functional magnetic resonance imaging studies. Results revealed that, compared with individuals without depression, individuals with depression showed higher activation in the anterior cingulate gyrus, insula, and middle frontal gyrus (MFG) for positive emotional stimuli and higher activation in the MFG, inferior frontal gyrus, and insula for negative emotional stimuli. Moreover, we identified that the MFG was consistently activated in individuals with depression regardless of the type of emotional stimuli. However, we did not find distinct patterns of brain activity between positive and negative emotional stimuli in individuals with depression. Our results demonstrated that both positive and negative emotional stimuli processing shares the same cognitive control-related brain regions in individuals with depression.

The associations between area-level residential instability and gray matter volumes from the North American Prodrome Longitudinal Study (NAPLS) consortium

INTRODUCTION

Area-level residential instability (ARI), an index of social fragmentation, has been shown to explain the association between urbanicity and psychosis. Urban upbringing has been shown to be associated with reduced gray matter volumes (GMV)s of brain regions corresponding to the right caudal middle frontal gyrus (CMFG) and rostral anterior cingulate cortex (rACC). We hypothesize that greater ARI will be associated with reduced right CMFG and rACC GMVs.

METHODS

Data were collected at baseline as part of the North American Prodrome Longitudinal Study Phase 2. Counties where participants resided during childhood were geographically coded using the US Census to area-level factors. ARI was defined as the percentage of residents living in a different house 5 years ago. Generalized linear mixed models tested associations between ARI and GMVs.

RESULTS

This study included 29 healthy controls (HC)s and 64 clinical high risk for psychosis (CHR-P) individuals who were aged 12 to 24 years, had remained in their baseline residential area, and had magnetic resonance imaging scans. ARI was associated with reduced right CMFG (adjusted β = -0.258; 95% CI = -0.502 to -0.015) and right rACC volumes (adjusted β = -0.318; 95% CI = -0.612 to -0.023). The interaction term (ARI-by-diagnostic group) in the prediction of both brain regions was not significant, indicating that the relationships between ARI and regional brain volumes held for both CHR-P and HCs.

CONCLUSIONS

ARI may adversely impact similar brain regions as urban upbringing. Further investigation into the potential mechanisms of the relationship between ARI and neurobiology, including social stress, is needed.

Sex-specific cognitive effects of mild traumatic brain injury to the frontal and temporal lobes

BACKGROUND

Cognitive deficits are the most enduring and debilitating sequelae of mild traumatic brain injury (mTBI). However, relatively little is known about whether the cognitive effects of mTBI vary with respect to time post-injury, biological sex, and injury location.

OBJECTIVES

The aim of this study was to assess the effect of the side and site of mTBI and to determine whether these effects are sexually dimorphic.

METHODS

Male and female ICR mice were subjected to either a sham procedure or mTBI to the temporal lobes (right-sided or left-sided) or to the frontal lobes (bilateral) using a weight-drop model. After recovery, mice underwent a battery of behavioral tests at two post-injury time points.

RESULTS

Different mTBI impact locations produced dissociable patterns of memory deficits; the extent of these deficits varied across sexes, time points, and memory domains. In both sexes, frontal mTBI mice exhibited a delayed onset of spatial memory deficits. Additionally, the performance of the frontal and left temporal injured males and females was more variable than that of controls. Interestingly, only in females does the effect of mTBI on visual recognition memory depend on the time post-injury. Moreover, only in females does spatial recognition memory remain relatively intact after mTBI to the left temporal lobe.

CONCLUSION

This study showed that different mTBI impact sites produce dissociable and sex-specific patterns of cognitive deficits in mice. The results emphasize the importance of considering the injury site/side and biological sex when evaluating the cognitive sequelae of mTBI.

Does positive feeling lead to more impulsiveness? - Implication of previous rewarded experience on location-dependent motoric impulsivity

Positive feeling or rewarding experience is crucial for individuals to operative their cognitive activities via an outcome evaluation of incentive reinforcement. For a long time, rewarding process or outcome evaluation is assumed greatly influenced by neuronal construct that holds individuals' impulsiveness, a capacity to inhibit unwanted behaviors provoked in a given situation. In the present study, we proposed that the outcome evaluation or rewarding experience can influence the occurrence of impulsiveness too. We hypothesized that animals would be more likely to deliver impulsive action in the place where it was previously associated with reinforcing process, in which central dopamine may play an important role. By employing five-choice serial reaction time task (5-CSRTT), we examined whether one of the five holes where rats made a correct response to get the reward would gain a higher probability to deliver premature or perseverative activities than other holes in the next trial of 5-CSRTT under baseline or longer waiting period condition. The effects of D1 receptor antagonist SCH23390 were also evaluated in the above paradigm. We demonstrated that (i) the influence on motoric impulsive response from previous rewarded experience can be described in a behavioral paradigm such as the 5-CSRTT, (ii) both prematures and perseverations at the hole associated with previous rewarding were about one-fifth of probability, however were statistically not correlated unless the interventions of inter-trial interval = 7 plus SCH23390, and (iii) the hole associated with the positive reinforcement of the 5-CSRTT appears more likely for rats to carry out an intuitive impetus under SCH23390 in a longer waiting condition. Our results may shed some insight toward the role of rewarding process in impulsive behavior.

The Apathy Evaluation Scale (AES-C): Psychometric Properties and Invariance of Italian Version in Mild Cognitive Impairment and Alzheimer's Disease

Apathy is a neuropsychiatric symptom observed in different neurological and psychiatric disorders. Although apathy is considered a symptom, it has been recently reconsidered as a syndrome characterised by three dimensions: cognitive symptoms, affective symptoms and behavioural symptoms. Recent studies have shown that apathy can be considered as a prodromal symptom of Alzheimer's disease (AD), but also an indicator of the transition from mild cognitive impairment to AD. According to this scenario, an early detection of apathy in subjects with Mild Cognitive Impairment (MCI) and Mild AD can be a valid psychometric strategy to improve an early diagnosis and promote a prompt intervention. The Apathy Evaluation Scale is a validated tool composed of 18 items that assess and quantify emotional, behavioural and cognitive aspects of apathy. The aim of this study is to assess the specific reliability and validity of the Italian version of the Apathy Evaluation Scale-Clinician Version (AES-C) to detect apathy both in amnestic MCI and mild AD patients. In the present paper, we therefore examined the psychometric properties and the invariance of the Italian Version of the AES-C conducted on a sample composed of an experimental group of amnestic MCI and AD patients (N = 107) and a control group (N = 107) constituted by Age- and Sex-matched healthy controls. Results confirm the goodness of the scale. Confirmatory factory analysis confirmed that the AES-C Italian Version presents the same stability of one second-order factor and three first-order factors identified in the original version, and all items are predicted by a single general factor. Moreover, the scale was found to be invariant across both populations. Moreover, reliability and discriminant analysis showed good values. We found in the experimental group a negative correlation between the AES-C and Frontal Assessment Battery (FAB) (rs = -0.21, p < 0.001) and Mini Mental State Examination (MMSE) (rs = -0.04, p < 0.001), while a positive correlation was found between the AES-C and Hamilton psychiatric Rating scale for Depression (HAM-D) scores (rs = 0.58, p < 0.001) Overall, our data demonstrated the validity of the Italian version of the AES-C for the assessment of apathy both in MCI and in AD patients.

Degeneration of core neural tracts for emotional regulation in a patient with traumatic brain injury: A case report

RATIONALE

Several brain structures, including the orbital prefrontal cortex, ventrolateral prefrontal cortex, dorsolateral prefrontal cortex, amygdala, and anterior cingulate cortex, are considered key structures in the neural circuitry underlying emotion regulation. We report on a patient showing behavior changes and degeneration of core neural tracts for emotional regulation following traumatic brain injury (TBI).

PATIENT CONCERNS

A 51-year-old male patient suffered an in-car accident. The patient lost consciousness for approximately 30 days, and his Glasgow Coma Scale score was 3. He underwent stereotactic drainage for traumatic intraventricular and intracerebral hemorrhages. At approximately 6.5-year after onset, he began to show disinhibition behaviors such as shouting with anger, which worsened over time. At approximately 8-year after onset, he showed severe depression signs and disinhibition, including violence.

DIAGNOSES

The patient who showed delayed-onset behavioral changes (disinhibition and depression).

INTERVENTIONS

Diffusion tensor imaging data were acquired at 3 months and 8 years after TBI onset.

OUTCOMES

The patient showed degeneration of core neural tracts for emotional regulation that was associated with delayed behavioral changes following TBI. On both 3-month and 8-year diffusion tensor tractographies (DTTs), the right dorsolateral prefronto-thalamic tract, ventrolateral prefronto-thalamic tract, orbital prefronto-thalamic tract, uncinate fasciculus, and both cinguli were reconstructed whereas other neural tracts were not reconstructed. Compared with the 3-month DTT, all reconstructed neural tracts on the 8-year DTT were narrow, except for the left cingulum, which showed new transcallosal fibers between both anterior cingula. The fractional anisotropy and tract volume of all reconstructed neural tracts were lower on the 8-year DTT than the 3-month DTT, except for the tract volume of left cingulum.

LESSONS

The evaluation of dorsolateral, ventrolateral, and orbital prefronto-thalamic tract, uncinate fasciculus, and cingulum using follow-up DTTs is useful when a patient with TBI shows delayed-onset behavioral problems.

The Frontal Behavioral Battery: A Measure of Frontal Lobe Symptoms in Brain Aging and Neurodegenerative Disease

BACKGROUND

Approximately 90%of persons living with dementia experience behavioral symptoms, including frontal lobe features involving motivation, planning, social behavior, language, personality, mood, swallowing, and gait.

OBJECTIVE

We conducted a two-stage study with a development sample (n = 586) and validation sample (n = 274) to evaluate a brief informant-rated measure of non-cognitive features of frontal lobe dysfunction: the Frontal Behavioral Battery (FBB).

METHODS

In the development sample, internal consistency, principal factor analysis, and correlations between the FBB and outcomes were evaluated. In the validation sample, we examined (a) FBB scores by diagnosis, (b) known-group validity by demographics, subjective complaints, and dementia staging, and (c) correlation between FBB and MRI volumes. Receiver operator characteristic curves assessed the ability of the FBB to discriminate individuals with frontal lobe features due to a neurodegenerative disease.

RESULTS

The FBB characterized 11 distinct frontal lobe features. Individuals with dementia with Lewy bodies and frontotemporal degeneration had the greatest number of frontal lobe features. Premorbid personality traits of extroversion, agreeableness, and openness were associated with fewer frontal lobe behavioral symptoms, while subjective cognitive complaints were associated with greater symptoms. The FBB provided very good discrimination between individuals with and without cognitive impairment (diagnostic odds ratio: 13.1) and between individuals with and without prominent frontal lobe symptoms (diagnostic odds ratio: 84.8).

CONCLUSION

The FBB may serve as an effective and efficient method to assess the presence of non-cognitive symptoms associated with frontal lobe dysfunction, but in a brief fashion that could facilitate its use in clinical care and research.