Electrophysiological signs of peripheral nerve dysfunction in progressive myoclonus epilepsy (original) (raw)
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The Egyptian Journal of Neurology, Psychiatry and Neurosurgery
Background Electrophysiological techniques have been used for discriminating myoclonus from other hyperkinetic movement disorders and for classifying the myoclonus subtype. This study was carried out on patients with different subtypes of myoclonus to determine the electrophysiological characteristics and the anatomical classification of myoclonus of different etiologies. This study included 20 patients with different subtypes of myoclonus compared with 30 control participants. Electrophysiological study was carried out for all patients by somatosensory evoked potential (SSEP) and electroencephalography (EEG) while the control group underwent SSEP. SSEP was evaluated in patients and control groups by stimulation of right and left median nerves. Results This study included 50 cases with myoclonus of different causes with mean age of 39.3 ± 15.7 and consisted of 23 males and 27 females. Twenty-nine (58%) of the patients were epileptics, while 21 (42%) were non-epileptics. Cases were c...
Neurophysiology of myoclonus and progressive myoclonus epilepsies
Epileptic disorders : international epilepsy journal with videotape, 2016
The high temporal resolution of neurophysiological recordings makes them particularly suited to faithfully describing the time course of rapid events such as myoclonus and to precisely measure its time relationship with other related activities. In progressive myoclonus epilepsies (PMEs) polygraphy with simultaneous EMG-EEG recordings is a crucial tool for defining the characteristic of myoclonic jerks their topography over different muscles (namely antagonists), their time course and relationship with vigilance muscle activation and stimulations. Moreover on polygraphic recordings it is possible to detect EEG activities associated to myoclonic jerks and define their time relationship with myoclonus thus differentiating cortical types of myoclonus from subcorticallly generated ones. Tanks to the back averaging technique non obvious time-locked EEG potentials can be detected on polygraphy , furthermore in stimulus sensitive myoclonus the analysis can include the potential evoked by t...
Cortical reactivity in progressive myoclonus epilepsy
Electroencephalography and Clinical Neurophysiology, 1994
We studied 4 patients with progressive myoclonus epilepsy (Unverricht-Lundborg disease; ULD). Somatosensory evoked fields (SEFs), auditory evoked fields (AEFs), and spontaneous activity over the somatomotor cortex were recorded with a 24-channel SQUID gradiometer. All patients had "giant" 20-45 msec median nerve SEFs at the first somatomotor cortex, with 2-6 times larger amplitudes than the healthy control subjects. Later deflections were not similarly enhanced. The dependence of SEF amplitudes on interstimulus interval (0.2-4 sec) and on successive ulnar-median nerve stimulation (stimulus interval 40 msec) was comparable to that in controls. Cortical AEFs were attenuated and delayed. In 3 patients, the spontaneous activity consisted of 6-8 Hz mu rhythm, which originated within 2 cm from the sources of SEFs and was abolished by clenching of the contralateral fist. Control subjects had major spectral peaks around 10 and 20 Hz. The SEF amplitudes and the strength of the 6-10 Hz mu correlated strongly, suggesting that some components of evoked and spontaneous activity obtain contributions from overlapping neuronal populations. The results imply that ULD is associated with thalamo-cortical hyperreactivity in the sensorimotor but not in the auditory system.
Journal of Neurology, Neurosurgery & Psychiatry, 1986
A patient is described who had a combination of stimulus-sensitive cortical myoclonus, epilepsia partialis continua, and Jacksonian motor epilepsy. He eventually required surgery because of the severity of his seizures. Electrophysiological recordings made before and during surgery, and PET scans performed before surgery identified an abnormal area of cerebral cortex in the postcentral parietal region. It is suggested that the stimulus-sensitive myoclonus arose because input into this region from peripheral sensory afferents produced an abnormal discharge which was fed forwards via cortico-cortical connections to the precentral motor cortex, to produce a reflex muscle jerk. The epilepsia partialis continua may have been caused by spontaneous discharges arising in the same region of parietal cortex. Both forms of jerking disappeared after resection of this part of the
Clinical study of myoclonic epileptic syndromes
International Journal of Advances in Medicine, 2016
Background: Incidence of different myoclonic epileptic syndromes is variable in different regions. Here in as there is very few literature available internationally being inclusive of all myoclonic epilepsies together. Very few studies are available which describe all characteristics in a given study population. The aim of the study was to find incidence of different types of myoclonic epilepsies among patients presenting with myoclonic seizures their characteristics and to study all myoclonic epilepsies and juvenile myoclonic epilepsy in the study population. Methods: In this study conducted in neurological unit at Ruby hall clinic, a total of 188 case of epileptic disorder were enrolled irrespective of age and sex, among 136 were new case of epileptic disorder were classified based on seizure pattern, 23 were new cases of myoclonic epilepsy, these 23 new case of myoclonic epilepsy along with 52 old cases of myoclonic epilepsy attending to neurological unit were clubbed, a total of 75 cases myoclonic epilepsy were studied. All cases of myoclonic epilepsy and juvenile myoclonic epilepsy were studied with respect to age of onset different seizures, relation with family history, response to treatment, EEG findings. Results: Out of 136 cases 23 were new cases of myoclonic epilepsy, these 23 newly diagnosed cases of myoclonic epilepsies along with 52 already diagnosed myoclonic epilepsy are clubbed together, total of 75 cases were further studied. Incidence of myoclonic epilepsy among epileptic patients found to be 16.9%. Incidence of JME among myoclonic epilepsies is 75-80%, in all myoclonic epilepsies and JME association with GTCS, family history, EEG abnormalities were common finding, valproate and leviteracetam are good therapeutic options, carbamazepine aggravated myoclonus. Conclusions: For diagnosis of myoclonic epilepsy proper clinical history stress laid to ask history of myoclonic jerk in case of all seizure disorder, diagnosis basically depends on proper knowledge of myoclonic epileptic syndrome, eliciting history, EEG as an ancillary testing when in doubt always expert opinion is required as misdiagnosis of the myoclonus as partial seizure leads to wrong prescription of carbamazepine which exacerbates the myoclonus.
Perioral Reflex Myoclonias: A Controlled Study in Patients with JME and Focal Epilepsies
Epilepsia, 2006
Purpose: Perioral reflex myoclonias (PORM) are obvious, frequent, but often unobserved focal seizures in different epileptic syndromes and the leading seizure type in reading epilepsy. PORMs remain often undiagnosed because the patients are not aware that these are epileptic seizures and fail to report them. Their semiology is not fundamentally different in various epileptic syndromes.
Generalised electrographic seizures presenting as perioral myoclonia
Epileptic disorders : international epilepsy journal with videotape, 2014
A 41-year-old man, during a neurological consultation, reported "chin twitching" over a period of a week, which was diagnosed as intermittent perioral myoclonia. With only one tonic-clonic seizure seven years before, he had mentioned several episodes of chin twitching over the years. In the clinic, there were intermittent chin movements without apparent confusion, as he was able to provide a complete history and was fully oriented with intact memory. His video-EEG showed paroxysms of polyspike and slow-wave activity, with the longest burst-free interval being 20 seconds. Discharges were maximal over the fronto-central regions, correlating with the chin myoclonus. He was able to tap his hand continuously, and remained alert. The case represents an atypical presentation of idiopathic generalised epilepsy without manifestation of absence or limb myoclonus. Although juvenile myoclonic epilepsy and other idiopathic epilepsies are rarely associated with perioral myoclonia, this ...