Dopaminergic medication unrelated myoclonus is less related to tremor in idiopathic Parkinson's disease

Myoclonus in Parkinson's disease (PD) may be related or unrelated to dopaminergic medication and may share some features of cortical myoclonus. The aim of this study was to analyze clinical and electrophysiological correlates of the dopaminergic treatment unrelated myoclonus in PD patients. We included 17 PD patients with the end-of-dose myoclonus and 16 PD patients without myoclonus between January 2010 and June 2011. Surface electromyography of upper extremity muscles and long latency reflexes (LLRs) were performed. Positive or negative myoclonus with a duration of 35-100 ms was observed. Rest tremor was less frequent in the group with myoclonus. Only one PD patient with myoclonus had C reflex. Mean LLR amplitude was significantly high in PD with myoclonus compared to the group without myoclonus (p = 0.024). Dopaminergic treatment unrelated myoclonus is less related to rest tremor in PD, may be positive or negative, and exhibits similar features to cortical myoclonus

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 különböző 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 longlatency 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. = Háttér és cél – A hosszú latenciájú reflexválaszoknak és a kevert idegek csendes periódusainak elektrofiziológiai módszerekkel való vizsgálata lehetôvé teszi a központi ideg rendszer szenzomotoros funkcióinak tanulmányozását. Jelen vizsgálatunk célja a hosszú latenciájú reflexválaszok és a kevert idegek csendes periódusainak összehasonlí - tása volt különbözô hipokinetikus mozgási rendelle nes sé - gekben, annak érdekében, hogy olyan elektrofiziológiai jeleket ta lál junk, amelyek alkalmasak megkülönböz te - tésükre. Módszerek – 39 idiopathiás Parkinson-kórban (IPD), 12 mul tiszisztémás atrófiában (MSA), 10 corticobasalis szind - rómában (CBS), 5 progresszív szupranukleáris paresisben (PSP) szenvedô beteget és 26 egészséges kontrollszemélyt vontunk be a vizsgálatba. Min den résztvevô esetében rögzítettük a szegmentális reflexet, a hosszú latenciájú reflexeket és a kevert idegek csendes periódusait. Eredmények – C-reflex-, hosszú latenciájú reflex-I- és hosszú latenciájú reflex-III-válaszokat nem kaptunk PSPben szenvedô betegeknél. A hosszú latenciájú reflex - amplitúdó/F-amplitúdó arány szignifikánsan alacsonyabb volt az IPD- és a PSP-bete geknél, mint az egészséges kont - rollszemélyek nél (p=0,036, p=0,006). A kevert idegek csendes perió du sának végén je lent kezô latenciák szignifikánsan hosszabbak voltak az IPD-, az MSA- és a CBScsoportokban, mint az egészséges kont roll személyeknél (p=0,026, p=0,050, p=0,008). Következtetés – Véleményünk szerint a hosszú latenciájú ref lexválaszok, különösen a C-reflex-válaszok rögzítése ígé retes eszköz lehet a CBS és az MSA PSP-tôl való megkülönböztetésében. A klinikai leleteket és az agytörzsi reflex válaszokat egyaránt tartalmazó, prospektív vizsgálatok további információt nyújthatnak

Auditory startle reflex and startle reflex to somatosensory inputs in generalized dystonia

Objective: Startle reflex is a generalized defense reaction after unexpected auditory, visual, or tactile stimuli. Auditory startle reflex (ASR) and startle reflex to somatosensory inputs (SSS) have never been studied in generalized dystonia. Here, we aimed to study the characteristics and changes of ASR and SSS in this group

Myoclonus in the elderly: A retrospective analysis of clinical and electrophysiological characteristics of patients referred to an electrophysiology laboratory

Background and objective: Late-onset myoclonus in the elderly is mainly related to dementia or systemic disease. In this report, we aimed to investigate the clinical and electrophysiological features of patients with late-onset myoclonus

Cortical Relay Time Shortens in Parkinson's Disease with Apraxia

Cortical relay time (CRT) is a neurophysiologic method that measures transmission between sensory and motor cortices. In this study, we calculated CRT to evaluate intrahemispheric transmission in idiopathic Parkinson's disease (PD). We recorded the following parameters: 1) long latency reflexes (LLRs), 2) motor-evoked potentials (MEPs), and 3) somatosensory-evoked potentials (SEPs) according to previously published reports, and cortical relay time was calculated using the following formula: Latency of LLR II - (onset latency of MEP response + latency of N20 response of SEP). CRT was shorter in patients with apraxia compared with patients without apraxia. The findings may raise the possibility of intrahemispheric aberrant conduction or abnormal synaptic reorganization in the presence of apraxia in PD

Electrophysiological Investigations in Orthostatic Myoclonus: Preliminary Findings

We report the clinical and electrophysiological findings in seven patients with orthostatic myoclonus (OM) associated with gait initiation failure and falls. OM is one of the causes of unsteadiness of stance and gait, and it may develop as a symptom of neurodegenerative disorders. Both positive myoclonic bursts and negative myoclonus may be seen in electrophysiological recordings, and electrophysiological analysis suggests a subcortical origin for OM

Neuroacanthocytosis in a psychiatry clinic: a case report

Neuroacanthocytosis (NA) syndromes are a group of genetically defined diseases characterized by peripheral blood acanthocytes, central nervous system as well as neuromuscular symptoms. The clinical presentation of neuroacanthocytosis typically includes chorea and dystonia. Psychiatric and cognitive symptoms may be significant including obsessive-compulsive disorder, depression and schizophrenia-like psychosis. Here, we aim to discuss a case presented with psychiatric symptoms and orofacial dyskinesia with the diagnosis of neuroacanthocytosis. A 25 year-old man was admitted to our outpatient clinic with depression, tongue biting and a speech disorder alleviated. His symptoms began after the death of his mother one year ago. Psychiatric examination showed that he had depression childish speaking as well as behavioral abnormalities. His history revealed dependent personality disorder. Neurological examination showed chorea, tics in his face and arms and hypotonia in all extremities. His cranial magnetic resonance imaging was normal, muscle enzymes were elevated, peripheral blood smear showed increased number of acanthocytes. The differential diagnosis was made between chorea-acanthocytosis, McLeod's syndrome and Huntington's disease. The gene analysis for Huntington's disease was negative, his lipid profile was normal. Symptomatic treatment was commenced