Music can be reconstructed from human auditory cortex activity using nonlinear decoding models.

Music is core to human experience, yet the precise neural dynamics underlying music perception remain unknown. We analyzed a unique intracranial electroencephalography (iEEG) dataset of 29 patients who listened to a Pink Floyd song and applied a stimulus reconstruction approach previously used in the speech domain. We successfully reconstructed a recognizable song from direct neural recordings and quantified the impact of different factors on decoding accuracy. Combining encoding and decoding analyses, we found a right-hemisphere dominance for music perception with a primary role of the superior temporal gyrus (STG), evidenced a new STG subregion tuned to musical rhythm, and defined an anterior-posterior STG organization exhibiting sustained and onset responses to musical elements. Our findings show the feasibility of applying predictive modeling on short datasets acquired in single patients, paving the way for adding musical elements to brain-computer interface (BCI) applications.

Clinical, biochemical, and molecular insights into Cerebrotendinous Xanthomatosis: A nationwide study of 100 Turkish individuals.

OBJECTIVE: Cerebrotendinous xanthomatosis (CTX) is an inherited metabolic disorder characterized by progressive neurologic and extraneurologic findings. The aim of this retrospective, descriptive study was to explore the time of presentation and diagnosis, and to expand the phenotype and genotype of CTX, based on a nationwide and comprehensive series of patients in Turkey. METHODS: The demographic, clinical, biochemical and genotypic characteristics of the CTX patients were reviewed. Data on molecular analysis, age of onset and diagnosis, diagnostic delay, neurologic and extraneurologic symptomatology, results of plasma cholestanol levels, brain magnetic resonance imaging and electromyography at the time of diagnosis were reviewed. RESULTS: 100 confirmed CTX patients from 72 families were included. The mean age at diagnosis was 28.16 ± 14.28 years, and diagnostic delay was 18.39 ± 13.71 years. 36 patients were diagnosed in childhood. Frequency of intention tremor (p = 0.069), peripheral neuropathy (p = 0.234) and psychiatric manifestations (p = 0.396) did not differ between two groups, demonstrating the high rate in pediatric patients. Three adult patients showed a milder phenotype without neurologic involvement. Seven patients had normal plasma cholestanol levels despite neurological impairment. Sequencing of the CYP27A1 gene revealed 25 different variants, with a novel c.671_672del variant not previously described in literature. CONCLUSION: Based on the observations of this Turkish CTX cohort, it is emphasized that the true prevalence of CTX is probably underestimated and that it has a wide spectrum of clinical phenotypes even without neurological impairment. In children, abnormal cerebellar findings, peripheral neuropathy and psychiatric findings associated with intellectual disability have been suggested as warning signs to avoid diagnostic delay. In cases of clinical suspicion, molecular analysis is recommended despite normal plasma cholestanol levels, as severe neurologic involvement may occur in CTX patients without elevated cholestanol levels.

Responsive Versus Continuous Deep Brain Stimulation for Speech in Essential Tremor: A Pilot Study.

BACKGROUND: Responsive deep brain stimulation (rDBS) uses physiological signals to deliver stimulation when needed. rDBS is hypothesized to reduce stimulation-induced speech effects associated with continuous DBS (cDBS) in patients with essential tremor (ET). OBJECTIVE: To determine if rDBS reduces cDBS speech-related side effects while maintaining tremor suppression. METHODS: Eight ET participants with thalamic DBS underwent unilateral rDBS. Both speech evaluations and tremor severity were assessed across three conditions (DBS OFF, cDBS ON, and rDBS ON). Speech was analyzed using intelligibility ratings. Tremor severity was scored using the Fahn-Tolosa-Marin Tremor Rating Scale (TRS). RESULTS: During unilateral cDBS, participants experienced reduced speech intelligibility (P = 0.025) compared to DBS OFF. rDBS was not associated with a deterioration of intelligibility. Both rDBS (P = 0.026) and cDBS (P = 0.038) improved the contralateral TRS score compared to DBS OFF. CONCLUSIONS: rDBS maintained speech intelligibility without loss of tremor suppression. A larger prospective chronic study of rDBS in ET is justified. © 2024 International Parkinson and Movement Disorder Society.

Electrodiagnostic methods to verify Guillain-Barré syndrome subtypes in Istanbul: A prospective multicenter study.

BACKGROUND AND AIMS: This study aimed to identify the clinical characteristics and electrodiagnostic subtypes of Guillain-Barré syndrome (GBS) in Istanbul. METHODS: Patients with GBS were prospectively recruited between April 2019 and March 2022 and two electrodiagnostic examinations were performed on each patient. The criteria of Ho et al., Hadden et al., Rajabally et al., and Uncini et al. were compared for the differentiation of demyelinating and axonal subtypes, and their relations with anti-ganglioside antibodies were analyzed. RESULTS: One hundred seventy-seven patients were included, 69 before the coronavirus disease 2019 pandemic (April 2019-February 2020) and 108 during the pandemic (March 2020-March 2022), without substantial changes in monthly frequencies. As compared with the criteria of Uncini et al., demyelinating GBS subtype diagnosis was more frequent according to the Ho et al. and Hadden et al. criteria (95/162, 58.6% vs. 110/174, 63.2% and 121/174, 69.5%, respectively), and less frequent according to Rajabally et al.'s criteria (76/174, 43.7%). Fourteen patients' diagnoses made using Rajabally et al.'s criteria were shifted to the other subtype with the second electrodiagnostic examination. Of the 106 analyzed patients, 22 had immunoglobulin G anti-ganglioside antibodies (14 with the axonal subtype). They had less frequent sensory symptoms (54.5% vs. 83.1%, p = 0.009), a more frequent history of previous gastroenteritis (54.5% vs. 22.9%, p = 0.007), and a more severe disease as compared with those without antibodies. INTERPRETATION: Serial electrodiagnostic examinations are more helpful for accurate subtype diagnosis of GBS because of the dynamic pathophysiology of the disease. We observed no significant increase in GBS frequency during the pandemic in this metropolis.

Impulse control disorders in Parkinson's disease: a retrospective analysis of 1824 patients in a 12-year period.

OBJECTIVE: This study aims to clinically evaluate the impulse control disorders (ICDs) encountered in treating Parkinson's disease. METHOD: This is a retrospective analysis between 2010 and 2022. We retrieved the medical records of all patients diagnosed with idiopathic Parkinson's disease. The demographic and clinical findings were recorded. ICDs constituted a specific item in the examination, and each one (compulsive shopping, compulsive eating, pathological gambling, hypersexuality, punding, dopamine dysregulation syndrome, and hobbyism) was noted separately. RESULTS: In the study period, we identified 1824 patients (56.2% men, n = 1025). The mean age was 70.5 ± 11.9 years. In the cohort, 128 (7%) patients with Parkinson's disease had one or more ICDs. The ICDs were compulsive shopping, punding/hobbyism, compulsive eating, hypersexuality, pathological gambling, and dopamine dysregulation syndrome. When we compared patients with and without ICDs, patients with ICDs were younger (p ≤ 0.001), and the men/women ratio was higher in this group with ICDs. Although the mean daily pramipexole dose was higher in patients with ICDs, mean daily long-acting pramipexole dose was only 1.4 ± 0.92 mg/day. CONCLUSION: The significant findings in this study were (i) the lower frequency of ICDs (7%); (ii) the common occurrence of compulsive shopping, punding/hobbyism, and compulsive eating; and (iii) the development of ICDs under relatively lower doses of pramipexole. We suggest that ICDs in Parkinson's disease should be associated with a personal trait with dopamine agonists, and potential electrophysiological or genetic markers of this trait warrant further analysis to avoid treatment in these patients.

Perspectives of Implementation of Closed-Loop Deep Brain Stimulation: From Neurological to Psychiatric Disorders.

BACKGROUND: Deep brain stimulation (DBS) is a highly efficient, evidence-based therapy to alleviate symptoms and improve quality of life in movement disorders such as Parkinson's disease, essential tremor, and dystonia, which is also being applied in several psychiatric disorders, such as obsessive-compulsive disorder and depression, when they are otherwise resistant to therapy. SUMMARY: At present, DBS is clinically applied in the so-called open-loop approach, with fixed stimulation parameters, irrespective of the patients' clinical state(s). This approach ignores the brain states or feedback from the central nervous system or peripheral recordings, thus potentially limiting its efficacy and inducing side effects by stimulation of the targeted networks below or above the therapeutic level. KEY MESSAGES: The currently emerging closed-loop (CL) approaches are designed to adapt stimulation parameters to the electrophysiological surrogates of disease symptoms and states. CL-DBS paves the way for adaptive personalized DBS protocols. This review elaborates on the perspectives of the CL technology and discusses its opportunities as well as its potential pitfalls for both clinical and research use in neuropsychiatric disorders.

A comparative transcranial magnetic stimulation study: Assessing cortical excitability and plasticity in Alzheimer's disease, dementia with Lewy bodies and Frontotemporal dementia.

BACKGROUND: Here, we aimed to investigate the roles of long-term potentiation-like (LTP-like) plasticity using intermittent theta burst (iTBS) protocol and resting motor threshold (rMT) in the differential diagnosis of Alzheimer's disease (AD), diffuse dementia with Lewy bodies (DLB) and frontotemporal dementia (FTD). METHOD: We enrolled 21 subjects with AD, 28 subjects with DLB, 14 subjects with FTD, and 33 elderly subjects with normal cognitive functions into the study. We recorded rMT and percentage amplitude change of motor evoked potentials (MEPs) after the iTBS protocol in each group. RESULTS: In patients with AD and DLB, the percentage amplitude change of MEPs, and rMTs were significantly lower than in healthy subjects. However, no significant difference was observed in individuals with FTD. CONCLUSION: Our findings showed that transcranial magnetic stimulation measures, particularly rMTs and LTP-like plasticity, may be potential biomarkers to distinguish between different dementia subtypes. Impaired motor cortical excitability and synaptic plasticity were more prominent in AD and DLB than in FTD. This aligns with the evidence that cortical motor networks are usually spared in FTDs in early-to-middle stages.

Identification and classification of pathology and artifacts for human intracranial cognitive research.

Intracranial electroencephalography (iEEG) presents a unique opportunity to extend human neuroscientific understanding. However, typically iEEG is collected from patients diagnosed with focal drug-resistant epilepsy (DRE) and contains transient bursts of pathological activity. This activity disrupts performances on cognitive tasks and can distort findings from human neurophysiology studies. In addition to manual marking by a trained expert, numerous IED detectors have been developed to identify these pathological events. Even so, the versatility and usefulness of these detectors is limited by training on small datasets, incomplete performance metrics, and lack of generalizability to iEEG. Here, we employed a large annotated public iEEG dataset from two institutions to train a random forest classifier (RFC) to distinguish data segments as either 'non-cerebral artifact' (n = 73,902), 'pathological activity' (n = 67,797), or 'physiological activity' (n = 151,290). We found our model performed with an accuracy of 0.941, specificity of 0.950, sensitivity of 0.908, precision of 0.911, and F1 score of 0.910, averaged across all three event types. We extended the generalizability of our model to continuous bipolar data collected in a task-state at a different institution with a lower sampling rate and found our model performed with an accuracy of 0.789, specificity of 0.806, and sensitivity of 0.742, averaged across all three event types. Additionally, we created a custom graphical user interface to implement our classifier and enhance usability.

Ataxia in a Movement Disorders Outpatient Clinic: a Single-Center Experience in Turkey.

The etiology may not be determined in patients with ataxia despite detailed evaluations. The aim of this study was to investigate the clinical and laboratory characteristics of a large cohort of patients with adult-onset ataxia of different etiologies, particularly, undetermined etiologies despite extensive clinical, genetic, laboratory, electrophysiological, and imaging investigations. The medical records of all patients diagnosed with ataxia of subacute-chronic onset between January 2011 and March 2021 were reviewed retrospectively. The records of patients with symptom onset after 16 years of age were included in the study. In all patients, clinical and demographic findings were noted. Etiologies were classified as acquired, hereditary, degenerative (multiple system atrophy-cerebellar, MSA-C), functional, and undetermined. During the study period, we determined 74 patients with ataxia and 59 (35 males) patients met the study criteria. The age range was 22-87 years. The etiologies were hereditary (n = 19), acquired (n = 14), MSA-C (n = 9), functional (n = 2), and undetermined (n = 15). The patients with hereditary etiologies and undetermined causes were significantly younger at admission and at symptom onset (p = 0.001 and p = 0.000). There was a significant delay until diagnosis in patients with hereditary etiologies compared to other etiologies. In acquired etiologies, axial findings (71.4%) were more prominent whereas extremity and axial findings were more common in patients with hereditary etiologies (83.3%, p = 0.030). There were systemic and radiological indicators such as hearing loss, juvenile cataract, or dentate hyperintensity in certain disorders. Hereditary etiologies are as common as acquired or degenerative etiologies in adults. However, they have an earlier onset and delayed diagnosis. Therefore, we should recognize the extracerebellar neurological, systemic, and neuroimaging findings.

Segmental Reflex, Long Latency Reflex, and Mixed Nerve Silent Period in Dystonia.

We hypothesized that "long latency reflexes" (LLRs), associated segmental reflex (SR), and mixed nerve silent periods (MnSPs) recorded on the distal upper extremity muscles would behave differently in patients with cervical dystonia and focal hand dystonia. We enrolled patients with cervical dystonia, generalized dystonia, focal hand dystonia, and healthy individuals. We recorded SR, LLRs, and MnSPs. The mean amplitude of SR on the affected side of focal hand dystonia was significantly lower (p = 0.010). The parameters related to LLRs and MnSPs were not different between groups. We suggest, using SR, LLRs, and MnSPs, we could not show an electrophysiological signature specific to dystonia.

Nociceptive flexion reflex in small fibers neuropathy and pain assessments†.

BACKGROUND: The nociceptive flexion reflex (NFR) is a polysynaptic and multisegmental spinal reflex that develops in response to a noxious stimulus and is characterized by the withdrawal of the affected body part. The NFR possesses two excitatory components: early RII and late RIII. Late RIII is derived from high-threshold cutaneous afferent A-delta fibers, which are prone to injury early in the course of diabetes mellitus (DM) and may lead to neuropathic pain. We investigated NFR in patients with DM with different types of polyneuropathies to analyze the role of NFR in small fiber neuropathy (SFN). METHODS: We included 37 patients with DM and 20 healthy participants of similar age and sex. We performed the Composite Autonomic Neuropathy Scale-31, modified Toronto Neuropathy Scale, and routine nerve conduction studies. We grouped the patients into large fiber neuropathy (LFN), SFN, and no overt neurological symptom/sign groups. In all participants, NFR was recorded on anterior tibial (AT) and biceps femoris (BF) muscles after train stimuli on the sole of the foot, and NFR-RIII findings were compared. RESULTS: We identified 11 patients with LFN, 15 with SFN, and 11 with no overt neurological symptoms or signs. The RIII response on the AT was absent in 22 (60%) patients with DM and 8 (40%) healthy participants. The RIII response on the BF was absent in 31 (73.8%) patients and 7 (35%) healthy participants (P = .001). In DM, the latency of RIII was prolonged, and the magnitude was reduced. Abnormal findings were seen in all subgroups; however, they were more prominent in patients with LFN compared to other groups. CONCLUSIONS: The NFR-RIII was abnormal in patients with DM even before the emergence of the neuropathic symptoms. The pattern of involvement before neuropathic symptoms was possibly related to an earlier loss of A-delta fibers.

Cutaneous silent period modulation by tooth clenching, tonic and phasic limb movements in healthy subjects.

OBJECTIVE: We aimed to examine the modulation of the cutaneous silent period (CSP) by tooth clenching and contralateral tonic dorsiflexion of lower limb and phasic voluntary movements of upper limb. METHODS: In 18 healthy subjects, we recorded CSP on right thenar muscle after painful stimulation of index finger during mild contraction at six conditions: baseline, maximum tooth clenching, contralateral tonic dorsiflexion of foot, as well as at the beginning (RT1), in the middle (RT2) and at last part (RT3) of the contralateral phasic wrist extension. We measured latency and duration and calculated suppression indices. RESULTS: During tooth clenching, the suppression index of second inhibitory phase (I2) was significantly higher than that at baseline condition. The suppression index of first inhibitory phase (I1) was reduced in tonic dorsiflexion. The I2 durations in RT2 and RT3 were longer than that at baseline. The I2 suppression indices during RT1, RT2, and RT3 were significantly higher than that at baseline condition (p < 0.05). CONCLUSION: The tooth clenching has an inhibitory effect on CSP. The contralateral phasic hand movements caused higher suppression index. The CSP is modulated by remote influences differently depending on the type of muscle contraction (tonic vs. phasic) and/or where it is realized (tooth, upper or lower limb).

Treatment of multiple sclerosis-related trigeminal neuralgia with onabotulinumtoxinA.

BACKGROUND: The effectiveness of onabotulinumtoxinA (BTX-A) has been established in primary trigeminal neuralgia (TN). However, to the best of our knowledge, the efficacy of BTX-A in secondary TN has not yet been studied. OBJECTIVE: This study aimed to investigate the efficacy of BTX-A treatment in patients with multiple sclerosis-related trigeminal neuralgia (TN-MS) and compare the efficacy of BTX-A treatment between patients with primary trigeminal neuralgia (TN-P) and patients with TN-MS. METHODS: This was a retrospective medical record-review study. Demographic and clinical features and severity and frequency of pain before and 2 weeks after the BTX-A administration were extracted from the patient files. BTX-A was injected into the painful area subcutaneously and/or submucosally. BTX-A injections were performed by the same physician using the same methods. A reduction in severity and/or frequency of pain ≥50% was considered therapeutic efficacy. RESULTS: Fifty-three patients were included in this study. We classified 22 (42%) as TN-P and 31 (58%) as TN-MS. Treatment with BTX-A was effective in 16 of 31 (52%) patients with TN-MS and 10 of 22 (45%) with TN-P. BTX-A treatment was less effective in patients with a history of interventional treatments and more effective in patients with concomitant continuous pain (p = 0.007; odds ratio [OR]: 0.020-0.53 and p = 0.047; OR: 0.046-0.98, respectively). CONCLUSION: The BTX-A treatment was found to be effective in at least half of our cohort with TN-MS. Concomitant continuous pain and history of interventional treatments to the trigeminal nerve or ganglion might be predictive factors for the efficacy of BTX-A treatment.

ADCY5 gene mutation: a case report.

BACKGROUND: ADCY5 mutation is a clinical condition that has been described in limited numbers in the literature, causing hyperkinetic movement disorder, and may be sporadic or familial. PATIENT DESCRIPTION: This report looks at the involuntary movements that started early in life in a 5-year-old girl. RESULTS: Patient's electroensephalogram and cranial magnetic resonance imaging were normal. Metabolic scans were normal. ADCY5 mutation was found in whole exome sequencing of the patient who did not have a similar family history. CONCLUSION: Some features such as the worsening of involuntary movements after sleep and the presence of hypotonia in our patient suggested this mutation. Our patient is resistant to more than one drug. With this report, we aimed to pave the way for better understanding of the gene and the discovery of different treatment options.

Postural tremor in L-2-hydroxyglutaric aciduria is associated with cerebellar atrophy.

OBJECTIVE: In this study, we performed analysis of brainstem reflexes and movement disorders using surface polymyogram in L-2-hydroxyglutaric aciduria (L2HGA). We also reviewed all cases in the literature with detailed clinical and radiological description to analyze the anatomical correlates of involuntary movements. PATIENTS AND METHOD: We performed surface electromyography of appropriate muscles, long-loop reflexes, and somatosensory evoked potentials and analyzed the neuroimaging findings in patients with L2HGA and recorded blink reflex (BR), auditory startle response (ASR), and startle response after somatosensory stimuli (SSS) in patients and healthy subjects. We also performed a systematic literature search to identify the association of neuroimaging findings and movements disorders in previous patients with L2HGA. RESULTS: Thirteen patients were enrolled in the study. Among them, ten had low-amplitude postural tremor with a frequency between 4 and 7 Hz. The tremor was predominant on distal parts of the upper extremities. Postural tremor was accompanied by negative myoclonus in one-third. The BR, ASR, and SSS, all, were hypoactive. There was a close association of postural tremor with cerebellar atrophy in patients who participated in this study and by the analysis of the previously reported patients. CONCLUSIONS: Low-amplitude postural tremor is common in L2HGA. It is related with cerebellar atrophy. Although the neuroimaging shows no overt lesions at the brainstem, there is a functional inhibition at this level.

Autonomic and neuropathic complaints of long-COVID objectified: an investigation from electrophysiological perspective.

PURPOSE: Here , we aimed to assess the frequency and phenomenology of autonomic and neuropathic complaints of long-COVID and to evaluate them by means of electrophysiology. METHODS: Step 1. Patients with prior COVID-19 infection were screened by COMPASS-31 and mTORONTO to create the target population for further evaluation. Step 2. Patients with high scores were invited for a detailed history of their complaints and electrophysiological analysis, which included nerve conduction studies, cutaneous silent period (CSP), and sympathetic skin response (SSR). We also constituted a control group composed of healthy subjects of similar age and sex for electrophysiological analysis. RESULTS: There were 106 patients, who matched the study criteria. Among them, thirty-eight patients (%35.8) had neuropathic or autonomic complaints or both. Fatigue and headache were significantly more frequent in patients with autonomic and neuropathic complaints. Detailed examination and electrophysiological evaluation were performed in 14 of 38 patients. Neuropathic complaints were patchy and proximally located in the majority. The entire CSP suppression index was higher in the patients (p = 0.002). There was no difference in palmar and plantar SSR between patients and healthy subjects. mTORONTO scores were negatively correlated with palmar and plantar SSR amplitudes, and the correlation was moderate. CONCLUSION: Neuropathic or autonomic complaints were seen in more than one-third of patients with long-COVID. Neuropathic complaints were generally patchy, proximally predominant, asymmetric, or diffuse. The CSP suppression index was abnormal whereas SSRs were normal.

Long latency trigemino-cervical reflex in restless legs syndrome.

OBJECTIVE: The trigemino-cervical complex (TCC) seems under dopaminergic inhibitory control and the abnormalities of trigemino-cervical reflex (TCR) have been reported in disorders associated with the dopaminergic system and various pain disorders. If the inhibitory response in TCC is likely dopaminergic, we hypothesized that TCR, which has never been evaluated in restless legs syndrome (RLS) patients before, would be also abnormal. METHODS: TCR was recorded from bilateral sternocleidomastoid and splenius capitis muscles in consecutive 15 drug-naive RLS patients and 16 age- and sex-matched healthy subjects. The right and left infraorbital branches of the trigeminal nerve were stimulated by percutaneous electrical stimulation separately. The presence rates, onset latencies, amplitudes, and durations of responses were measured and compared between patients with RLS and controls. RESULTS: The presence rates, onset latencies and amplitudes of TCR responses were similar between RLS patients and controls, however, the durations of responses were bilaterally longer in RLS patients compared to healthy volunteers. CONCLUSIONS: Hyperexcitability of TCR suggests defective sensory processing in the brainstem probably due to impairment of descending inhibitory dopaminergic system in RLS. The sensitization of TCC in RLS patients may also be a possible factor that might explain the association of RLS and pain disorders.

Genetic variants of vitamin D metabolism-related DHCR7/NADSYN1 locus and CYP2R1 gene are associated with clinical features of Parkinson's disease.

PURPOSE/AIM OF THE STUDY: Parkinson's disease (PD) is the second most common neurodegenerative disorder. Vitamin D deficiency is suggested to be related to PD. A genome-wide association study indicated that genes involved in vitamin D metabolism affect vitamin D levels. Among these genes, single nucleotide polymorphisms (SNPs) of the vitamin D receptor (VDR) and vitamin D binding protein (VDBP/GC) genes have also been demonstrated to be associated with PD risk. Our aim was to investigate the relevance of SNPs within the 7-dehydrocholesterol reductase/nicotinamide adenine dinucleotide synthetase 1 (DHCR7/NADSYN1) locus and vitamin D 25-hydroxylase (CYP2R1) gene, which encode important enzymes that play a role in the vitamin D synthesis pathway, with PD and its clinical features. MATERIALS AND METHODS: Genotypes of 382 PD patients and 240 cognitively healthy individuals were evaluated by a LightSNiP assay for a total of 10 SNPs within the DHCR7/NADSYN1 locus and CYP2R1 gene. RESULTS: There were no significant differences in the allele and genotype distributions of any of the SNPs between any patient groups and healthy subjects. However, our results indicated that all of the SNPs within the DHCR7/NADSYN1 locus and CYP2R1 gene, except rs1993116, were associated with clinical motor features of PD including initial predominant symptom, freezing of gait (FoG) and falls as well as disease stage and duration of the disease. CONCLUSIONS: In conclusion, genetic variants of the DHCR7/NADSYN1 locus and the CYP2R1 gene might be related to the inefficient utilization of vitamin D independent from vitamin D levels, and it might result in differences in the clinical features of PD patients.

Hand Pronation-Supination Movement as a Proxy for Remotely Monitoring Gait and Posture Stability in Parkinson's Disease.

The Unified Parkinson's Disease Rating Scale (UPDRS) is a subjective Parkinson's Disease (PD) physician scoring/monitoring system. To date, there is no single upper limb wearable/non-contact system that can be used objectively to assess all UPDRS-III motor system subgroups (i.e., tremor (T), rigidity (R), bradykinesia (B), gait and posture (GP), and bulbar anomalies (BA)). We evaluated the use of a non-contact hand motion tracking system for potential extraction of GP information using forearm pronation-supination (P/S) motion parameters (speed, acceleration, and frequency). Twenty-four patients with idiopathic PD participated, and their UPDRS data were recorded bilaterally by physicians. Pearson's correlation, regression analyses, and Monte Carlo validation was conducted for all combinations of UPDRS subgroups versus motion parameters. In the 262,125 regression models that were trained and tested, the models within 1% of the lowest error showed that the frequency of P/S contributes to approximately one third of all models; while speed and acceleration also contribute significantly to the prediction of GP from the left-hand motion of right handed patients. In short, the P/S better indicated GP when performed with the non-dominant hand. There was also a significant negative correlation (with medium to large effect size, range: 0.3-0.58) between the P/S speed and the single BA score for both forearms and combined UPDRS score for the dominant hand. This study highlights the potential use of wearable or non-contact systems for forearm P/S to remotely monitor and predict the GP information in PD.

[Comparison of long-latency reflex and mixed nerve silent period responses in various hypokinetic movement disorders]. / A hosszú latenciájú reflexválaszoknak és a kevert idegek csendes periódusainak összehasonlítása különbözo hipokinetikus mozgási rendellenességekben.

Background and purpose: Long-latency reflex and mixed nerve silent period responses are electrophysiological methods to study the sensorimotor functions of the central nervous system. Here we aimed to study long-latency reflexes and mixed nerve silent period responses in different types of hypokinetic movement disorders in order to find an electrophysiological landmark to distinguish them. Methods: We included 39 patients with idiopathic Parkinson's disease (IPD), 12 patients with multiple system atrophy (MSA), 10 patients with corticobasal syndrome (CBS), 5 patients with progressive supranuclear palsy (PSP) and 26 healthy participants. We recorded the segmental reflex, the long-latency reflexes and the mixed nerve silent period responses for each participant. Results: C reflex, long-latency reflex-I and long-latency reflex-III responses were not obtained in any patients with PSP. Long-latency reflex amplitude/ F amplitude ratio was significantly lower in patients with IPD and PSP compared to healthy individuals (p=0.036, p=0.006 respectively). The mixed nerve silent period end latencies were significantly longer in IPD, MSA, CBS groups compared to the healthy individuals (p=0.026, p=0.050, p=0.008 respectively). Conclusion: We suggest that recording long-latency reflex, particularly C reflex responses may provide promising results in distinction of CBS and MSA from PSP. Prospective studies with clinical findings and brainstem reflexes may offer more information.