Effect of sleep quality on memory, executive function, and language performance in patients with refractory focal epilepsy and controlled epilepsy versus healthy controls - A prospective study.

We aimed to evaluate the effect of sleep quality on memory, executive function, and language performance in patients with refractory focal epilepsy and controlled epilepsy and compare these with healthy individuals. We prospectively enrolled 37 adolescent and adult patients with refractory focal epilepsy (Group 1) and controlled epilepsy (Group 2) in each group. History pertaining to epilepsy and sleep were recorded, and all patients underwent overnight polysomnography. Language, memory, and executive function assessments were done using Western Aphasia Battery, Post Graduate Institute (PGI) memory scale, and battery of four executive function tests (Trail Making Test A & B, Digit symbol test, Stroop Task, and Verbal Fluency Test), respectively. Forty age- and sex-matched controls were also included in the study. Significant differences were noted in both objective and subjective sleep parameters among all the groups. On polysomnography, parameters like total sleep time, sleep efficiency, sleep latency, and rapid eye movement (REM) latency were found to be significantly worse in Group 1 as compared with Group 2. Cognitive and executive parameters were significantly impaired in Group 1. Shorter total sleep time, poorer sleep efficiency, and prolonged sleep latencies were observed to be associated with poor memory and executive function in patients with refractory epilepsy. Our study strongly suggests that sleep disturbances, mainly shorter total sleep time, poor sleep efficiency, and prolonged sleep latencies, are associated with impaired memory and executive function in patients with refractory focal epilepsy and to a lesser extent, among those with medically controlled epilepsy.

Evaluation of the diagnostic yield of ARQIP: A new restless legs syndrome diagnostic questionnaire and validation of its Hindi translation.

BACKGROUND: Restless legs syndrome (RLS) is misdiagnosed due to a variety of clinical presentations and lack of a diagnostic biomarker. Sociocultural differences in patients' reporting of symptoms further contribute to this under diagnosis. We developed an expanded diagnostic tool for RLS, incorporating all International RLS Study Group (IRLSSG) diagnostic criteria with a number of additional questions mainly focusing on specific sociocultural influences in RLS symptom reporting among Indians. The purpose of this study was to examine the change in the diagnostic yield of RLS, if any, through administration of this expanded questionnaire. MATERIALS AND METHODS: The AIIMS RLS questionnaire for Indian patients (ARQIP) was developed in English language, and then translated into Hindi. All consecutive patients attending Neurology and sleep disorders clinic with complaints of leg discomfort were recruited in the study. Two examiners evaluated all patients with complaints of leg discomfort seen by a senior Sleep Medicine expert, one using only IRLSSG diagnostic criteria and the other using the ARQIP. Patients were categorized as RLS or "no-RLS" by the expert, and this was considered as the "standard" for analysis. RESULTS: A total of 155 participants (78 males, 50.3%) with a mean age of 44.1 ± 14.5 years were enrolled. A total of 105 patients were diagnosed as having RLS (group 1) and the rest as having "non-RLS" (group 2). The ARQIP was found to have a much higher sensitivity (100% vs 73%), specificity (44% vs 32.7%), negative predictive value (100% vs 36.4%), and positive predictive value (79% vs 70%) compared to the standard questionnaire. The diagnostic yield of this tool was 26.7% (Confidence interval = 100-73.3). CONCLUSIONS: The ARQIP for RLS diagnosis, validated in this study, has been observed to have a high sensitivity and a negative predictive value with a high diagnostic accuracy.

Evidence of mutations in RIC3 acetylcholine receptor chaperone as a novel cause of autosomal-dominant Parkinson's disease with non-motor phenotypes.

BACKGROUND: The known genetic determinants of Parkinson's disease (PD) do not explain all cases investigated to date. Contemporary sequencing technologies hold promise for enhanced causal variant discovery. We attempted to identify the putative causal variant in an Indian PD family by whole exome sequencing (WES). METHODS: WES data generated for two affected cousins from a 14-member PD family with some non-motor phenotypes were analysed. Variants prioritised were checked for segregation with disease by targeted sequencing. An independent PD cohort (n=280) was screened for additional mutations in the prioritised gene. Variants were functionally validated in PC12 cells differentiated into neurons. RESULTS: A heterozygous mutation c.169C>A, p.P57T in RIC3 acetylcholine receptor chaperone (11p15) segregated with disease in the family confirming an autosomal-dominant mode of inheritance. Another heterozygous mutation c.502G>C, p.V168L was detected in an unrelated PD case. Both mutations were absent in 144 healthy control and in 74 non-PD WES data available in-house and in 186 age and sex-matched controls screened by PCR sequencing. RIC3 is a known chaperone of neuronal nicotinic acetylcholine receptor subunit α-7 (CHRNA7). Dominant negative effect of RIC3 mutants in transfected PC12 cells was reflected by the reduced levels of endogenous CHRNA7 in the membrane fractions in western blots and lower colocalisation profiles in confocal micrographs. CONCLUSION: The novel demonstration of a chaperone-mediated receptor density alteration due to RIC3 mutants provides strong evidence for the role of cholinergic pathway for the first time in PD aetiology. This may also be insightful for some non-motor symptoms and personalised treatment.

Discovery of a frameshift mutation in podocalyxin-like (PODXL) gene, coding for a neural adhesion molecule, as causal for autosomal-recessive juvenile Parkinsonism.

BACKGROUND: Mutations in known genes for inherited forms of Parkinson's disease (PD) account for <30% of familial PD (FPD) implying that more causal gene(s) remain to be identified. We attempted to discover the putative causal variant in an Indian family with autosomal-recessive juvenile Parkinsonism (ARJP), tested negative for mutations in PARK2, PINK1 and DJ1. METHODS: Whole exomes of two affected siblings were sequenced. Variants prioritised were screened for segregation with disease in the family by targeted sequencing. Gene thus identified was screened for index/additional exonic mutations, if any, in an independent PD cohort by PCR sequencing. Variants observed were functionally validated in differentiated PC12 cells. RESULTS: A novel homozygous frameshift mutation, c.89_90insGTCGCCCC in exon 1 of podocalyxin-like gene (PODXL, 7q32-33), resulting in loss of protein, segregated with disease in the family. Mutant allele was absent in 186 healthy controls screened by PCR sequencing and in control exomes available in the laboratory and public databases. Screening of additional 212 sporadic and 68 FPD cases identified three novel heterozygous missense variants namely c.1285C>A, c.1118G>A and c.881G>A in three unrelated cases. Significant differences in neurite branching and length (p<0.0001) were observed in PC12 cells with wild-type and mutant constructs. CONCLUSIONS: Based on the genetic and functional evidence in this study and literature support on the role of PODXL in neural development, a novel frameshift mutation in PODXL seems to be the likely cause of ARJP in this family. This is the first report suggesting the possible role of a neurodevelopmental pathway in PD aetiology.

Remission And relapse of myasthenia gravis on long-term azathioprine: An ambispective study.

INTRODUCTION: Azathioprine (AZA) is commonly used in myasthenia gravis (MG). Treatment may be prolonged, entailing significant risks and avoidable costs. METHODS: We reviewed remission, relapse, and side-effect profiles in MG patients on AZA during treatment and after tapering off. We conducted an ambispective study and analyzed remission, relapse rates, and side-effect profiles in 117 MG patients on AZA. RESULTS: Thirty-nine patients (33.3%) achieved remission, and 36 (30.8%) achieved complete stable remission (CSR), with a 33% relapse rate. No AZA side effects were seen in 95 (81%) patients. Only duration of disease of >10 years (odds ratio 9.5, 95% confidence interval 2.4-36.9, P = 0.001) was significantly associated with remission. CONCLUSIONS: AZA is well tolerated by MG patients, and about 30% go into CSR on long-term AZA. Muscle Nerve, 2016 Muscle Nerve 54: 405-412, 2016.

Spinocerebellar ataxia 7 (SCA7) in Indian population: predilection of ATXN7-CAG expansion mutation in an ethnic population.

BACKGROUND & OBJECTIVES: Spinocerebellar ataxia 7 (SCA7) is a rare form of neurodegenerative disorder with the clinical manifestation of cerebellar ataxia and retinal degeneration. In this study we describe the clinico-genetic characteristics of nine SCA7 families of Indian origin and cross compare these with other available worldwide studies. METHODS: Thirty five individuals from nine SCA7 families were clinico-genetically characterized and CAG repeat distribution analysis was carried out in 382 control DNA samples from healthy controls (derived from 21 diverse Indian populations based on ethnic and linguistic and geographical location). RESULTS: Of the nine families studied, 22 affected individuals and one asymptomatic carrier were identified. The average age at disease onset was 23.4±12.6 yr. The length of expanded CAG ranged from 40-94 with mean value of 53.2±13.9. The main clinical findings in affecteds individuals included cerebellar ataxia, and retinal degeneration along with hyper-reflexia (95%), slow saccades (85%) and spasticity (45%). Analysis of the association of number of CAG repeats with disease onset revealed that <49 repeats were associated with earlier age at onset in South East Asians compared to European populations. Further analysis of CAG repeats from 21 diverse Indian populations showed pre-mutable repeats (28-34) alleles in the IE-N-LP2 population. Six of the nine families identified in this study belonged to the same ethnic population. INTERPRETATIONS & CONCLUSION: Our results show that presenece of SCA7 is relatively rare and confined to one ethnic group from Haryana region of India. We observed a homogeneous phenotypic expression of SCA7 mutation as described earlier and an earlier age of onset in our patients with CAG <49. The identification of pre-mutable allele in IE-N-LP2 suggests this population to be at the risk of SCA7.

Correlation Between Structural and Functional Retinal Changes in Parkinson Disease.

BACKGROUND: To evaluate structural changes in the retina and correlate those with visual function measurements in patients with Parkinson disease (PD). METHODS: A cross-sectional comparative study of 20 patients with PD and 20 age-matched healthy controls was conducted. Visual acuity, color vision, contrast sensitivity, visual fields, pattern visual-evoked response (VER), and multifocal electroretinogram were recorded to determine functional change, whereas structural changes were evaluated with retinal nerve fiber layer (RNFL) thickness, macular thickness, macular volume, and ganglion cell-inner plexiform layer complex (GCL-IPL) thickness using spectral domain ocular coherence tomography (SD-OCT). RESULTS: PD patients ranged from Stage 1-3, with median Stage 2 (Hoehn and Yahr Classification) with mean Unified Parkinson Disease Rating Scale III score of 19 ± 10.42, and average disease duration of 5.8 ± 2.78 years. Visual acuity, color vision, and visual fields were unaffected but contrast sensitivity was significantly worse than controls (P < 0.001). Multifocal electroretinogram values in the central 2° field revealed decreased foveal electrical activity, with increased pattern VER amplitude and latency. Significant RNFL thinning was observed in the average RNFL (P = 0.033), superior (P = 0.018), and temporal (P = 0.036) quadrants. Significant ganglion cell layer loss was captured on SD-OCT with average, minimum GCL-IPL, and all 6 sectors showing thinning (P ≤ 0.003). The functional changes correlated significantly with structural changes, disease duration, and severity. There was no correlation between structural changes in the retina and disease duration or severity. CONCLUSIONS: Subclinical visual dysfunction was observed in patients with PD with good structural-functional correlation. GCL-IPL thinning may be a more reliable parameter than RNFL thickness for structural alterations of the retina in patients with PD.

Parkinsonian syndromes presenting with circadian rhythm sleep disorder- advanced sleep-phase type.

BACKGROUND: Circadian rhythm sleep disorder-advanced sleep-phase type is a relatively uncommon disorder, mostly seen among the elderly population. Impaired circadian rhythms have been reported in neurodegenerative conditions; however, there are no reports of any circadian rhythm sleep disorder among patients with Parkinsonian syndromes. We report two patients who presented with this circadian rhythm disorder, and were then diagnosed with a Parkinsonian syndrome. The cases. A 65-year-old retired man presented with history of abrupt change in sleep schedules, sleeping around 6.30-7 p.m. and waking up around 3-4 a.m. for the last 2 months. On detailed examination, the patient was observed to have symmetrical bradykinesia and cogwheel rigidity of limbs. A diagnosis of multiple system atrophy was made, supported by MRI findings and evidence of autonomic dysfunction. Symptoms of change in sleep-wake cycles resolved over the next 1 year, while the patient was treated with dopaminergic therapy. A 47-year-old man, who was being evaluated for presurgical investigation for refractory temporal lobe epilepsy, presented with complaints suggestive of dysarthria, bradykinesia of limbs and frequent falls for 5 months. Simultaneously, he began to sleep around 7 p.m. and wake up at about 2-3 a.m. Examination revealed severe axial rigidity, restricted vertical gaze and bradykinesia of limbs. A diagnosis of progressive supranuclear palsy was made. CONCLUSION: This is the first report of Parkinson's plus syndromes presenting with a circadian rhythm sleep disorder-advanced sleep-phase type. More prospective assessment for circadian sleep disorders may introduce useful insights into similar associations.

Queuing of concurrent movement plans by basal ganglia.

How the brain converts parallel representations of movement goals into sequential movements is not known. We tested the role of basal ganglia (BG) in the temporal control of movement sequences by a convergent approach involving inactivation of the BG by muscimol injections into the caudate nucleus of monkeys and assessing behavior of Parkinson's disease patients, performing a modified double-step saccade task. We tested a critical prediction of a class of competitive queuing models that explains serial behavior as the outcome of a selection of concurrently activated goals. In congruence with these models, we found that inactivation or impairment of the BG unmasked the parallel nature of goal representations such that a significantly greater extent of averaged saccades, curved saccades, and saccade sequence errors were observed. These results suggest that the BG perform a form of competitive queuing, holding the second movement plan in abeyance while the first movement is being executed, allowing the proper temporal control of movement sequences.

Fibroblast Growth Factor-2 alone as an efficient inducer for differentiation of human bone marrow mesenchymal stem cells into dopaminergic neurons.

BACKGROUND: The reported efficiency of differentiation of human bone marrow derived Mesenchymal Stem Cells (hBM MSC) into dopaminergic neurons with different inducers is found to vary. Thus, in the current study we have investigated the response of hBM MSC to some of the neuronal inducers and their combinations. Neuronal differentiation inducing agents Fibroblastic Growth Factor 2 (FGF2), Sonic Hedge Hog (Shh), Fibroblastic Growth Factor 8 (FGF8) & All Trans Retinoic Acid (ATRA) were used either singly or in varied combinations. RESULTS: The differentiated and undifferentiated hBM MSC were characterized in terms of morphology, expression of cell markers at transcriptional and translational levels, amount of dopamine secreted by the cells in the media and changes in cell membrane potential by calcium ions imaging. Induced hBM MSC revealed neuron like morphology and expressed cellular markers suggesting neuronal differentiation with all the inducing agents. However, upon quantitative analysis through qPCR, cells induced with FGF2 were found to show maximum expression of tyrosine hydroxylase (TH) by 47.5 folds. Immunofluorescence analysis of differentiated and undifferentiated cells also revealed expression of nestin, neurofilament, microtubule associated protein- 2, beta tubulin III and TH in differentiated cells, at translational level. This data was supported by immunoblotting analysis. Further, ELISA study also supported the release of dopamine by cultures induced with FGF2. When the cells were depolarised with KCl solution, those induced with Shh & FGF8 showed maximum calcium ion trafficking, followed by the cells induced with FGF2 only. CONCLUSIONS: We conclude that hBM MSC can be coaxed to differentiate efficiently into dopaminergic neurons in the presence of a very simple media cocktail containing only one main inducer like FGF2 and thus contribute towards cellular therapy in Parkinson's and other related disorders. These dopaminergic neurons are also functionally active, as shown by calcium ion trafficking.

Changes in psychiatric comorbidity during early postsurgical period in patients operated for medically refractory epilepsy--a MINI-based follow-up study.

PURPOSE: The purpose of this study was to assess axis-I DSM-IV psychiatric disorders in patients at baseline and 3 months after surgery for medically refractory temporal lobe epilepsy. METHOD: The Mini International Neuropsychiatric Interview (MINI) and Quality of Life in Epilepsy Inventory-10 (QOLIE-10) were evaluated before and 3 months after surgery in 50 consecutive patients (21 females, 29 males) with medically refractory temporal lobe epilepsy (persistent seizures>2/month, despite treatment with ≥2 appropriate drugs in adequate doses for ≥2 years) who underwent surgery [anterior temporal lobectomy with amygdalo-hippocampectomy (for mesial temporal sclerosis in 40), electrocorticography-guided lesionectomy (for other lesions in 10)]. RESULTS: Twenty-six patients (52%) had an axis-I psychiatric disorder [26% depressive disorder, 28% anxiety disorder] at baseline, while 30 (60%) patients had an axis-I psychiatric disorder [28% depressive disorder, 28% anxiety disorder] at 3 months after surgery. Twenty percent developed a new psychiatric disorder, while 12% showed improvement postsurgery. Mean QOLIE-10 scores improved from 23.78 to 17.80 [24 (48%) patients showed ≥5-point improvement]. Thirty-four (68%) patients had no seizure, 6 (12%) had non-disabling seizures, while 2 (4%) had disabling seizures after surgery. High frequency of seizures prior to surgery (p<0.038) and seizure occurrence after surgery (p<0.055) predicted the presence of psychiatric disorders after surgery. No clinical characteristic could predict development of new psychiatric disorder after surgery. CONCLUSION: Psychiatric dysfunction in the early postsurgery period is seen in nearly half of patients undergoing surgery for temporal lobe epilepsy, is mild in nature, and does not adversely affect quality of life but may cause significant clinical problems when it arises de novo postsurgery.

Screening of the GPX3 gene identifies the "T" allele of the SNP -861A/T as a risk for ischemic stroke in young Asian Indians.

BACKGROUND: Deficiency of plasma glutathione peroxidase (GPx-3) has been associated with platelet-dependent thrombosis. Single-nucleotide polymorphisms (SNPs) in the promoter region of GPX3 gene have been found associated with the risk for ischemic stroke in Caucasian populations. The aim of our present study was to evaluate the impact of genetic variations in the GPX3 gene and plasma GPx-3 antigen levels on ischemic stroke in young Asian Indians. METHODS: One hundred patients with ischemic stroke and 200 age- and sex-matched controls were studied. Genetic analysis for the study population was done by a combination of variant screening using single-stranded conformation polymorphism and final genotyping by polymerase chain reaction-restriction fragment length polymorphism and allele-specific polymerase chain reactions. Plasma GPx-3 antigen levels were evaluated using commercial kits. Data were analyzed using genetic analysis software and statistical tools. RESULTS: Significantly higher GPx-3 levels were observed in controls compared with patients (controls 26.37 ± 3.66 µg/mL and patients 22.83 ± 4.57 µg/mL, P < .001). Only the SNP -861A/T was found associated with stroke phenotype (P < .0001). The SNP -568T/C was observed to significantly influence plasma GPx-3 levels (P < .05). The haplotype carrying the risk "T" allele of SNP -861A/T was significantly over-represented in patients with stroke (P < .0001). CONCLUSIONS: The T allele of -861A/T is a risk allele for the ischemic stroke phenotype. The -861A/T and -568T/C SNPs may show a statistically significant association with both plasma GPx-3 antigen levels and the stroke phenotype in a larger sample size.

Role of platelets in neurodegenerative diseases: a universal pathophysiology.

Platelets play an important role in a variety of disorders, namely, cardiovascular, psychosomatic, psychiatric, thrombosis, HIV/AIDS in addition to various neurodegenerative diseases (NDDs). Recent evidence indicates that platelet react to diverse stressors, thereby offering an interesting vantage point for understanding their potential role in contemporary medical research. This review addresses the possible role of platelets as a systemic probe in various NDDs, such as amyotrophic lateral sclerosis, Parkinson's disease, Huntington's disease, Alzheimer's disease, multiple sclerosis, etc. The current review based on published literature, describes a probable link between platelets and pathophysiology of various NDDs. It also discusses how platelets epitomize ultrastructural, morphological, biochemical and molecular changes, highlighting their emerging role as systemic tools in different NDDs.

Use of Indian smell identification test for evaluating olfaction in idiopathic Parkinson's disease patients in India.

BACKGROUND: Olfactory dysfunction in Parkinson's Disease (PD) has been recognized for a long time and a number of studies have been performed in various parts of the world, using culturally appropriate smell identification tests. OBJECTIVE: In this study, for the first time, olfactory function has been assessed in the Indian Idiopathic Parkinson's Disease (IPD) patients using an indigenously developed smell test. MATERIALS AND METHODS: Olfaction was assessed in 53 IPD patients and 50 healthy controls using SniffIn-sticks ® test and Indian Smell Identification test (INSIT). In both these tests, the subjects were asked to identify the smell from a set of choices and were scored out of 10 and 12 for INSIT and SniffIn-sticks ® test, respectively. RESULTS: Both SniffIn-sticks ® test and INSIT showed significant impairment in olfaction in IPD patients (P < 0.001). There was no significant correlation of the scores of both tests with Hoehn and Yahr (H and Y) stage, duration of illness and Levodopa Equivalent Daily Dose (LEDD). The tests had a high correlation, r = 0.75 (P < 0.001) and the area under the Receiver Operating Characteristic (ROC) curves did not differ significantly. Using a cut off value of 4 (values ≤ 4 indicating disease), INSIT showed a sensitivity of 79.2% and specificity of 78%. CONCLUSION: INSIT, being cheap, convenient and more acceptable in the Indian population, can be considered as a better alternative for SniffIn-sticks ® test in the evaluation of olfaction in Indian PD subjects.

Exposure to extremely low-frequency magnetic field restores spinal cord injury-induced tonic pain and its related neurotransmitter concentration in the brain.

Spinal cord injury (SCI) is unequivocally reported to produce hyperalgesia to phasic stimuli, while both hyper- and hypoalgesia to tonic stimuli. The former is spinally mediated and the latter centrally. Besides, its management is unsatisfactory. We report the effect of magnetic field (MF; 17.96 µT, 50 Hz) on tonic pain behavior and related neurotransmitters in the brain of complete thoracic (T13) SCI rats at week 8. Adult male Wistar rats were divided into Sham, SCI and SCI+MF groups. Formalin-pain behavior was compared utilizing 5 min block pain rating (PR), 60 min session-PR, time spent in various categories of increasing pain (T0-T3) and flinch incidences. Serotonin (5-HT), dopamine (DA), norepinepherine (NE), gamma-aminobutyric acid (GABA), glutamate and glycine were estimated in brain tissue by liquid chromatography-mass spectrometry. Session-PR, block-PR and number of flinches were significantly lower, while time spent in categories 0-1 was higher in the SCI versus Sham group. These parameters were comparable in the SCI+MF versus Sham group. 5-HT concentration in cortex, remaining forebrain areas and brain stem (BS), was lower while GABA and NE were higher in BS of SCI, which were comparable with Sham in the SCI+MF group. The concentration of DA, glutamate and glycine was comparable amongst the groups. The data indicate significant hypoalgesia in formalin pain while increased in GABA, NE and decreased in 5-HT post-SCI, which were restored in the SCI+MF group. We suggest beneficial effect of chronic (2 h/day × 8 weeks) exposure to MF (50 Hz, 17.96 µT) on tonic pain that is mediated by 5-HT, GABA and NE in complete SCI rats.

Presynaptic membrane receptor in human brain.

Myasthenia gravis (MG) is an autoimmune disease that results from antibody mediated damage of Acetylcholine receptor (AChR) at the neuromuscular junction. The autoimmune character of MG and pathogenic role of AChR antibodies have been established by several workers i.e., the demonstration of anti-AChR antibodies in about 90 % of MG patients. It has been demonstrated that patients with MG also have antibodies against a second protein named presynaptic membrane receptor (PsmR), which is identified by utilizing ß-Bgtx, a ligand which binds to PsmR. Using ß-Bgtx Sepharose 4B affinity matrix, the PsmR was purified from different regions of human cadaver brain by affinity chromatography. Purified receptor was characterized both by biochemical and immunological procedures. PsmR purified from different regions of the brain shows a specific activity of 0.37 ± 0.01, 0.39 ± 0.02 and 0.43 ± 0.005 nM/ µg of protein in Parietal lobe, Occipital lobe and Frontal lobe respectively. The affinity purified PsmR from the brain of 87 and 68 kd (parietal lobe, occipital lobe and frontal lobe) shows immunoreactivity with myasthenic sera. These findings suggest that PsmR from brain is another antigen against which autoantibodies are developed in Myasthenia gravis patients. Upon treatment with various enzymes we concluded that PsmR from brain is a glycoprotein in which the immunoreactivity resides in the carbohydrate as well as the peptide epitopes. In conclusion the PsmR is another antigen against which autoantibodies are formed in different regions of brain. These can be used as a diagnostic tool for detecting antibodies in the sera or cerebrospinal fluid of MG patients.

Effect of rTMS at SMA on task-based connectivity in PD.

BACKGROUND: Transcranial magnetic stimulation (TMS) can aid in alleviating clinical symptoms in Parkinson's disease (PD). To better understand the neural mechanism of the intervention, neuroimaging modalities have been used to assess the effects of rTMS. OBJECTIVE: To study the changes in cortical connectivity and motor performance with rTMS at supplementary motor area (SMA) in PD using clinical assessment tools and task-based functional MRI. METHODOLOGY: 3000 pulses at 5 Hz TMS were delivered at the left SMA once a week for a total of 8 consecutive weeks in 4 sham sessions (week 1-4) and 4 real sessions (week 5 to week 8) in 16 subjects with PD. The outcomes were assessed with UPDRS, PDQ 39 and task-based fMRI at baseline, after sham sessions at week 4, and after real sessions at week 8. Visuo-spatial functional MRI task along with T1 weighted scans (at 3 Tesla) were used to evaluate the effects of rTMS intervention. Multivariate pattern analysis (MVPA) was used to analyse task-based fMRI using Conn toolbox. RESULTS: Improvements (p < 0.05) were observed in UPDRS II, III, Mobility and ADL of PDQ39 after real sessions of rTMS. MVPA of task-based connectivity revealed clusters of activation in right hemispheric precentral area, superior frontal gyrus, middle frontal gyrus, thalamus and cerebellum (cluster threshold pFDR=0.001). CONCLUSIONS: Weekly rTMS sessions at SMA incurred clinical motor benefits as revealed by an improvement in clinical scales and dexterity performance. These benefits could be attributed to changes in connectivity remote brain regions in the motor network.

Mechanisms of 1 Hz Inhibitory and 5 Hz Excitatory Repetitive Transcranial Magnetic Stimulations in Parkinson's Disease: A Functional Magnetic Resonance Imaging Study.

Background: Parkinson's disease (PD) is a progressive disorder with alterations in cortical functional activity. Transcranial magnetic stimulation is known to incur motor benefits in PD by inducing motor activity through cortical connectivity, although the mechanisms are unclear. Objective: The effects of repetitive transcranial magnetic stimulation (rTMS) (at three cortical sites) on functional and structural plasticity were studied in PD to understand inhibitory or excitatory rTMS-induced motor improvement. Methodology: The study was a single blind, randomized, sham-controlled type involving three groups. Three thousand rTMS pulses of frequency 1 Hz were given at primary motor area (in 13 patients of Group A) or premotor area (in Group B, n = 18) and a frequency 5 Hz at supplementary motor area in Group C (n = 19). Clinical rating scores (Unified Parkinson's Disease Rating Scale [UPDRS], Parkinson's Disease Questionaire-39 [PDQ-39]) and motor dexterity were assessed at baseline, after sham and real rTMS sessions. Visuospatial functional magnetic resonance imaging task along with T1-weighted scans (at three Tesla) were used to evaluate the motor execution and planning post rTMS intervention. Results: Improvements (p < 0.05) in UPDRS II, III, Mobility, and activities of daily living of PDQ-39, Purdue Pegboard were observed. Increased blood oxygen level-dependent (BOLD) activations (family-wise error [FWE]-corrected P-value [pFWE] <0.01) were observed in motor cortices, parietal association areas, and cerebellum in groups C and decrease in group A and B after real TMS as compared with sham. Conclusions: Repetitive TMS at motor (1 Hz) and supplementary motor (5 Hz) areas resulted in significant clinical benefits by inducing cortical plasticity. Impact statement TMS daily protocols have been commonly employed to modulate cortical connectivity in Parkinson's disease (PD). This study uses functional magnetic resonance imaging to assess rTMS-related effects in PD. Repetitive TMS protocol at higher pulses (3000/session) in primary and supplementary motor cortices administered weekly was clinically effective and safe. The results revealed functional restoration along with cortical plasticity mechanisms of externally generated movement in PD in response to noninvasive brain stimulation.