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Kolmančič K, Zupančič NK, Trošt M, Flisar D, Kramberger MG, Pirtošek Z, Kojović M. Continuous Dopaminergic Stimulation Improves Cortical Maladaptive Changes in Advanced Parkinson's Disease. Mov Disord 2022; 37:1465-1473. [PMID: 35436354 DOI: 10.1002/mds.29028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 03/10/2022] [Accepted: 03/27/2022] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND With the progression of Parkinson's disease (PD), pulsatile treatment with oral levodopa causes maladaptive changes within basal ganglia-thalamo-cortical circuits, which are clinically expressed as motor fluctuations and dyskinesias. At the level of the motor cortex, these changes may be detected using transcranial magnetic stimulation (TMS), as abnormal corticospinal and intracortical excitability and absent response to plasticity protocols. OBJECTIVE We investigated the effect of continuous dopaminergic stimulation on cortical maladaptive changes related to oral levodopa treatment. METHODS Twenty patients with advanced PD were tested using TMS within 1 week before and again 6 months after the introduction of levodopa-carbidopa intestinal gel. We measured resting and active motor thresholds, input/output curve, short interval intracortical inhibition curve, cortical silent period, and response to intermittent theta burst stimulation. Patients were clinically assessed with Part III and Part IV of the Movement Disorders Society Unified Parkinson's Disease Rating Scale. RESULTS Six months after the introduction of levodopa-carbidopa intestinal gel, motor fluctuations scores (P = 0.001) and dyskinesias scores (P < 0.001) were reduced. Resting and active motor threshold (P = 0.012 and P = 0.015) and x-intercept of input/output curve (P = 0.005) were also decreased, while short-interval intracortical inhibition and response to intermittent theta bust stimulation were improved (P = 0.026 and P = 0.031, respectively). Changes in these parameters correlated with clinical improvement. CONCLUSIONS In patients with advanced PD, switching from intermittent to continuous levodopa delivery increased corticospinal excitability and improved deficient intracortical inhibition and abnormal motor cortex plasticity, along with amelioration of motor fluctuations and dyskinesias. Continuous dopaminergic stimulation ameliorates maladaptive changes inflicted by chronic pulsatile dopaminergic stimulation. © 2022 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Kaja Kolmančič
- Department of Nuclear Medicine, University Clinical Centre, Ljubljana, Slovenia.,Department of Neurology, University Clinical Centre, Ljubljana, Slovenia
| | - Nina K Zupančič
- Department of Neurology, University Clinical Centre, Ljubljana, Slovenia
| | - Maja Trošt
- Department of Neurology, University Clinical Centre, Ljubljana, Slovenia.,Medical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Dušan Flisar
- Department of Neurology, University Clinical Centre, Ljubljana, Slovenia
| | - Milica G Kramberger
- Department of Neurology, University Clinical Centre, Ljubljana, Slovenia.,Medical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Zvezdan Pirtošek
- Department of Neurology, University Clinical Centre, Ljubljana, Slovenia.,Medical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Maja Kojović
- Department of Neurology, University Clinical Centre, Ljubljana, Slovenia
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Khedr EM, Mohamed KO, Ali AM, Hasan AM. The effect of repetitive transcranial magnetic stimulation on cognitive impairment in Parkinson's disease with dementia: Pilot study. Restor Neurol Neurosci 2021; 38:55-66. [PMID: 31815705 DOI: 10.3233/rnn-190956] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND The exact mechanism of cognitive impairment in PD is not known. Repetitive transcranial magnetic stimulation (rTMS) has been proposed as a possible treatment for cognitive impairment and to treat the motor symptoms in Parkinson's disease (PD) where its effects seem additive to those of dopaminergic medications. OBJECTIVE In this pilot study we investigated whether repeated sessions of rTMS have an effect on measures of cognitive impairment in patients with PD dementia. METHODS 33 patients with PD dementia were randomly assigned sham or real rTMS (2000 pulses; 20 Hz; 90% RMT; 10 trains of 10 s with 25 s between each train) over the hand area of each motor cortex (5 min between hemispheres) for 10 days (5 days/week) followed by 5 booster sessions every month for 3 months. Assessments included the Unified Parkinson's Disease Rating Scale part III (UPDRS), Montreal Cognitive Assessment (MoCA); Mini Mental State Examination (MMSE), Clinical Dementia Rating Scale (CDR); Memory and Executive Screening (MES) and Instrumental activity of Daily Living (IADL). Event related potentials (P300) and cortical excitability were measured before treatment and after the last session. RESULTS There were no significant differences in the effects of rTMS between groups. Although rTMS improved motor function in the active group it had only a minor effect on two of the dementia rating scores (the MMSE and MoCA) but not the others (CDR and MES). There was also a reduction in the latency of the P300 in the active group. CONCLUSIONS rTMS over M1 is useful for motor function and may have a small positive effect on cognition. However, better approaches for the latter are necessary, may be require multisite rTMS to target both motor and frontal cortical region.
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Affiliation(s)
- Eman M Khedr
- Department of Neuropsychiatry, Assiut University Hospital, Assiut, Egypt
| | - Khaled O Mohamed
- Department of Neuropsychiatry, Assiut University Hospital, Assiut, Egypt
| | - Anwar M Ali
- Department of Neuropsychiatry, Assiut University Hospital, Assiut, Egypt
| | - Asmaa M Hasan
- Department of Neuropsychiatry, Assiut University Hospital, Assiut, Egypt
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Khedr EM, Ahmed OG, Sayed HM, Abo-Elfetoh N, Ali AM, Gomaa AM. Electrophysiological differences in cortical excitability in different forms of dementia: A transcranial magnetic stimulation and laboratory biomarkers study. Neurophysiol Clin 2020; 50:185-193. [PMID: 32591186 DOI: 10.1016/j.neucli.2020.05.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 05/17/2020] [Accepted: 05/17/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The aim of the present study was to identify neurophysiologic markers to differentiate between Alzheimer dementia (AD), Vascular dementia (VaD), and Parkinson's disease dementia (PDD), and to examine their relationship to levels of transforming growth factor β1 (TGFβ1). METHODS The study included 15 patients with each type of dementia (AD, VaD, PDD) and 25 control subjects. Dementia patients were diagnosed according to the DiagnosticandStatisticalManualofMentalDisorders4thedition-revised(DSM-IV-R). Modified Mini Mental State Examination (MMMSE), motor cortex excitability including resting and active motor thresholds (rMT, aMT), input-output (I/O) curve, contralateral and ipsilateral silent periods (cSP, iSP), short-interval intracortical inhibition (SICI) at 1,2 and 4ms, and serum levels of TGFβ1 were examined. RESULTS There were no significant differences between groups with regards to age, sex, education or socioeconomic level. There was significant neuronal hyperexcitability in the form of reduced rMT and aMT and a shallower I/O curve in all three groups of dementia compared with the control group. The durations of cSP and iSP were longer in AD and PDD groups compared with the control group, whereas there were no significant differences in VaD. SICI was less effective in the three dementia groups than in the control group at intervals of 4ms. Serum levels of TGFβ1 were significantly elevated in all dementia groups in comparison with the control group. There was a significant negative correlation between serum level of TGFβ1 and cSP, iSP, and SICI across all patients and a significant negative correlation between serum level of TGFβ1 and iSP duration in AD. CONCLUSION Although motor thresholds were reduced in all patients, measures of SICI, cSP and iSP could distinguish between dementia groups. Serum level of TGFβ1 negatively correlated with iSP specifically in the AD group. This suggests that levels of TGFβ1 may relate to GABAergic dysfunction in dementia.
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Affiliation(s)
- Eman M Khedr
- Neurology and psychiatry department, Assiut university hospital, Assiut, Egypt.
| | - Omyma G Ahmed
- Medical physiology department, faculty of medicine, Assiut university, Assiut, Egypt
| | - Hanaa Mm Sayed
- Medical physiology department, faculty of medicine, Assiut university, Assiut, Egypt
| | - Noha Abo-Elfetoh
- Neurology and psychiatry department, Assiut university hospital, Assiut, Egypt
| | - Anwar M Ali
- Neurology and psychiatry department, Assiut university hospital, Assiut, Egypt
| | - Asmaa Ms Gomaa
- Medical physiology department, faculty of medicine, Assiut university, Assiut, Egypt
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Khedr EM, El Fawal B, Abdelwarith A, Nasreldein A, Rothwell JC, Saber M. TMS excitability study in essential tremor: Absence of gabaergic changes assessed by silent period recordings. Neurophysiol Clin 2019; 49:309-315. [DOI: 10.1016/j.neucli.2019.05.065] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 05/15/2019] [Accepted: 05/15/2019] [Indexed: 10/26/2022] Open
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Changes in recruitment of motor cortex excitation and inhibition in patients with drug-induced tardive syndromes. Neurophysiol Clin 2018; 49:33-40. [PMID: 30366858 DOI: 10.1016/j.neucli.2018.10.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 09/22/2018] [Accepted: 10/03/2018] [Indexed: 11/20/2022] Open
Abstract
OBJECTIVES It has recently been suggested that drug-induced tardive syndromes (TS) might be due to maladaptive plasticity, which increases motor excitability in cerebral cortex and basal ganglia. In order to test this hypothesis, we performed the first measurements of cortical excitability in TS. METHODS Motor cortex excitability was examined using transcranial magnetic stimulation (TMS) in 22 TS patients and compared with that in 20 age and sex-matched healthy individuals. Resting and active motor threshold (RMT, AMT) and input-output curves (I/O curves) assessed corticospinal excitability. The duration of the contralateral silent period (cSP) at a range of stimulation intensities and ipsilateral silent period (iSP) were used as measures of inhibition. RESULTS There were no significant differences in RMT and AMT between patients and controls, although the input-output curves were significantly steeper in patients. The cSP (at different stimulus intensities) and iSP were both longer in the patients compared to the control group. However, most of this difference could be accounted for by increased recruitment of motor evoked potentials (MEPs) in patients. CONCLUSION TS is characterized by hyperexcitability of corticospinal output that might contribute to the lack of selectivity in muscle recruitment and contribute to excess involuntary movement. The findings are opposite to those in naturally-occurring hyperkinesia such as Sydenham's and Huntington's chorea, suggesting a fundamental difference in the pathophysiology.
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Abstract
PURPOSE OF REVIEW To demonstrate how neurophysiological tools have advanced our understanding of the pathophysiology of paediatric movement disorders, and of neuroplasticity in the developing brain. RECENT FINDINGS Delineation of corticospinal tract connectivity using transcranial magnetic stimulation (TMS) is being investigated as a potential biomarker for response to therapy. TMS measures of cortical excitability and neuroplasticity are also being used to investigate the effects of therapy, demonstrating neuroplastic changes that relate to functional improvements. Analyses of evoked potentials and event-related changes in the electroencephalogaphy spectral activity provide growing evidence for the important role of aberrant sensory processing in the pathophysiology of many different movement disorders. Neurophysiological findings demonstrate that children with clinically similar phenotypes may have differing underlying pathophysiology, which in turn may explain differential response to therapy. Neurophysiological parameters can act as biomarkers, providing a means to stratify individuals, and are well suited to provide biofeedback. They therefore have enormous potential to facilitate improvements to therapy. SUMMARY Although currently a small field, the role of neurophysiology in paediatric movement disorders is poised to expand, both fuelled by and contributing to the rapidly growing fields of neuro-rehabilitation and neuromodulation and the move towards a more individualized therapeutic approach.
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Abstract
INTRODUCTION Chorea is defined as jerk-like movements that move randomly from one body part to another. It is due to a variety of disorders and although current symptomatic therapy is quite effective there are few etiology- or pathogenesis-targeted therapies. The aim of this review is to summarize our own experience and published evidence in the treatment of chorea. Areas covered: After evaluating current guidelines and clinical practices for chorea of all etiologies, PubMed was searched for the most recent clinical trials and reviews using the term 'chorea' cross referenced with specific drug names. Expert commentary: Inhibitors of presynaptic vesicular monoamine transporter type 2 (VMAT2) that cause striatal dopamine depletion, such as tetrabenazine, deutetrabenazine, and valbenazine, are considered the treatment of choice in patients with chorea. Some clinicians also use dopamine receptor blockers (e.g. antipsychotics) and other drugs, including anti-epileptics and anti-glutamatargics. 'Dopamine stabilizers' such as pridopidine and other experimental drugs are currently being investigated in the treatment of chorea. Deep brain stimulation is usually reserved for patients with disabling chorea despite optimal medical therapy.
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Affiliation(s)
- H Bashir
- a Parkinson's Disease Center and Movement Disorders Clinic, Department of Neurology , Baylor College of Medicine , Houston , TX , USA
| | - J Jankovic
- a Parkinson's Disease Center and Movement Disorders Clinic, Department of Neurology , Baylor College of Medicine , Houston , TX , USA
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Singer HS. Autoantibody-Associated Movement Disorders in Children: Proven and Proposed. Semin Pediatr Neurol 2017; 24:168-179. [PMID: 29103424 DOI: 10.1016/j.spen.2017.08.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Movement disorders secondary to autoantibodies in children represent a rapidly expanding group of conditions. Once considered to be limited to poststreptococcal Sydenham's chorea or rare cases of childhood systemic lupus erythematosus, a variety of antibody-related movement abnormalities are now seen as part of noninfectious autoimmune encephalitis or within an expanding list of postinfectious disorders. In this article, several proposed autoantibody-mediated movement disorders in children are reviewed. In each one, there is a hypothesized antibody biomarker that is believed to be pathogenic and cause the clinical symptoms. As will be discussed, in some, such as anti-NMDA receptor encephalitis, the strength of supporting evidence is strong. In others, antibodies have been identified, but their role as the pathophysiological mechanism remains undetermined. Lastly, there are proposed disorders, such as PANDAS, that are controversial on both a clinical and autoimmune basis.
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Affiliation(s)
- Harvey S Singer
- Departments of Neurology and Pediatrics, Johns Hopkins University, Baltimore MD.
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Khedr EM, Gabra RH, Noaman M, Abo Elfetoh N, Farghaly HSM. Cortical excitability in tramadol dependent patients: A transcranial magnetic stimulation study. Drug Alcohol Depend 2016; 169:110-116. [PMID: 27810653 DOI: 10.1016/j.drugalcdep.2016.09.027] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Revised: 09/04/2016] [Accepted: 09/20/2016] [Indexed: 12/01/2022]
Abstract
BACKGROUND Addiction to tramadol, a widely used analgesic, is becoming increasingly common. Tramadol can also induce seizures even after a single clinical dose. We tested whether the epileptogenicity of tramadol was associated with any changes in cortical excitability and inhibitory transmission using transcranial magnetic stimulation (TMS). METHODS The study included 16 tramadol dependent patients and 15 age and sex matched healthy volunteers. Clinical evaluation was conducted using an addiction severity index. TMS assessment of excitability was conducted on the motor cortex since the response to each TMS pulse at that site is easily measured in terms of the amplitude of the twitches it evokes in contralateral muscles. Measures included resting and active motor threshold (RMT and AMT respectively), motor evoked potential (MEP) amplitude, cortical silent period (CSP) duration, transcallosal inhibition (TCI), and short interval intracortical inhibition and facilitation (SICI and ICF respectively). Urinary level of tramadol was measured immediately before assessing cortical excitability in each patient. RESULTS RMT and AMT were significantly lower, the duration of the CSP was shorter and SICI was reduced in patients compared with the control group. These findings are suggestive of increased neural excitability and reduced GABAergic inhibition following exposure to tramadol. Also there were negative correlations between the severity of tramadol dependence and a number of cortical excitability parameters (AMT, RMT, and CSP with P=0.002, 0.005, and 0.04 respectively). CONCLUSIONS The results provide evidence for hyperexcitability of the motor cortex coupled with inhibitory deficits in tramadol dependent patients.
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Affiliation(s)
- Eman M Khedr
- Neuropsychiatry Department, Assiut University Hospital, Assiut, Egypt.
| | - Romany H Gabra
- Neuropsychiatry Department, Assiut University Hospital, Assiut, Egypt
| | - Mostafa Noaman
- Neuropsychiatry Department, Assiut University Hospital, Assiut, Egypt
| | - Noha Abo Elfetoh
- Neuropsychiatry Department, Assiut University Hospital, Assiut, Egypt
| | - Hanan S M Farghaly
- Pharmacology Department, Faculty of Medicine, Assiut University, Assiut, Egypt
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Weissbach A, Bäumer T, Brüggemann N, Tadic V, Zittel S, Cheng B, Thomalla G, Klein C, Münchau A. Premotor-motor excitability is altered in dopa-responsive dystonia. Mov Disord 2015; 30:1705-9. [DOI: 10.1002/mds.26365] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Revised: 07/09/2015] [Accepted: 07/13/2015] [Indexed: 12/17/2022] Open
Affiliation(s)
- Anne Weissbach
- Institute of Neurogenetics; University of Luebeck; Germany
- Department of Neurology; University of Luebeck; Germany
| | - Tobias Bäumer
- Institute of Neurogenetics; University of Luebeck; Germany
| | - Norbert Brüggemann
- Institute of Neurogenetics; University of Luebeck; Germany
- Department of Neurology; University of Luebeck; Germany
| | - Vera Tadic
- Institute of Neurogenetics; University of Luebeck; Germany
- Department of Neurology; University of Luebeck; Germany
| | - Simone Zittel
- Institute of Neurogenetics; University of Luebeck; Germany
| | - Bastian Cheng
- Department of Neurology; University Medical Center Hamburg-Eppendorf; Hamburg Germany
| | - Götz Thomalla
- Department of Neurology; University Medical Center Hamburg-Eppendorf; Hamburg Germany
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