1/717. bismuth encephalopathy. bismuth encephalopathy, characterized by the constant association of acute confusion, myoclonus, severe ataxia and dysarthia has reached "epidemic" proportion since its first description in 1974. The clinical aspects the pathogenic hypothesis, the diagnostic criteria as well as the report of a typical case are described by the authors, who stress the similarities with encephalopathies induced by other metals. ( info) |
2/717. Facial dyskinesia induced by auditory stimulation: a report of four cases. INTRODUCTION: The Vibroacoustic disease (VAD) is an occupational pathology induced by long-term (>10 yr) exposure to large pressure amplitude (> or = 90 dB SPL) and low frequency (< or = 500 Hz) noise. During studies contributing to the characterization of VAD, abnormal facial movements induced by repetitive auditory stimuli were observed in one individual employed as an aeronautical mechanic. The goal of this study was to investigate the existence of movement disorders triggered by auditory stimuli in a group of VAD-diagnosed patients. methods: Sixty VAD patients received auditory and median nerve stimulation. Simultaneously, EEG monitoring was performed. RESULTS: Abnormal myoclonus movements were triggered by auditory stimuli in four patients. EEG recordings were normal in all 60 patients. Stimulation of the median nerves did not trigger any abnormal movements. CONCLUSION: These data suggest that this facial dyskinesia has a subcortical origin. ( info) |
| The author recently encountered a patient with hiccups, intermittently accompanied by apparent focal rhythmic diaphragmatic myoclonus after hydrocodone administration. review of the literature disclosed a paucity of previous reports of hiccup, but many reports of myoclonus after opiate administration. A wide variety of opiates and routes of administration have been implicated, but high doses and the presence of other agents (antipsychotics, antiemetics, nonsteroidal antiinflammatory agents, antidepressants) may pose special risks. review of the literature suggests three types of opiate-related myoclonus. Opiate-induced myoclonus (OIM) is often generalized and is either periodic or associated with rigidity. Opiate-induced myoclonus frequently occurs in the context of underlying medical conditions, D2 antagonist coadministration, or other drugs (nonsteroidal anti-inflammatory agents, antidepressants), and usually responds to either naloxone or benzodiazepines. Intrathecal OIM has not been linked to D2 antagonist coadministration or benzodiazepine responsiveness but may be associated with non-steroidal antiinflammatory agents. Opiate withdrawal myoclonus may be stimulus-sensitive, associated with D2 antagonist coadministration, and responsive to benzodiazepines and unresponsive to naloxone. There are several problems in interpreting the literature, and more study is needed. Opiatergic, serotonergic, dopaminergic, and other mechanisms are considered. ( info) |
4/717. Bulbar myoclonus without palatal myoclonus. A hypothesis on pathophysiology. A 40-year-old woman with myoclonic contractions bilaterally in the infrahyoid neck muscles, especially in the left cricothyroid muscle, was presented and successfully treated with botulinum toxin injections. The patient had a wide, aberrant vessel curving into the left dorsolateral reticular formation of the medulla oblongata. Based on our observations, we propose that symptomatic bulbar and palatal myoclonus is caused by pathology in the dorsolateral reticular formation, and not by inferior olivary dysfunction as is currently thought. ( info) |
5/717. Paraneoplastic opsoclonus-myoclonus secondary to malignant melanoma. Opsoclonus-myoclonus is a well-described paraneoplastic syndrome that most often occurs in association with small cell carcinoma of the lung and breast carcinoma. To the best of our knowledge, we describe the first reported case of paraneoplastic opsoclonus-myoclonus occurring is association with malignant melanoma. Antineuronal antibodies were not identified despite repeated testing. No therapeutic benefit was observed following corticosteroid administration. ( info) |
6/717. Idiopathic cortical myoclonus restricted to the lower limbs: correlation between MEPs and 99mTc-ECD single photon emission computed tomography activation study. We report a 63-year-old woman with cortical reflex myoclonus restricted to the bilateral lower limbs. Somatosensory evoked cortical potentials to posterior tibial nerve stimulation were enlarged with C-responses. Jerk-locked back averaging of the EEG identified a cortical spike related to myoclonic jerks. Motor evoked potentials recorded from the abductor hallucis muscle showed an exaggerated late response. These findings suggest hyperexcitability of the sensorimotor cortex. 99mTc-ECD single photon emission computed tomography (SPECT) after stimulation of the posterior tibial nerve showed increased perfusion in the contralateral peri-Rolandic area which corresponded to the hyperexcitable region. A SPECT activation study as well as MEPs therefore can be employed to determine the hyperexcitable region in cortical myoclonus. ( info) |
7/717. Palatal myoclonus as a cause of objective tinnitus: a report of six cases and a review of the literature. We describe 6 new cases of palatal myoclonus (PM), a rare disorder that is characterized by involuntary rhythmic contraction of the palatal musculature. Although it has been reported that PM is a lifelong condition, one of our patients experienced a complete resolution of PM, which casts doubt on the accepted beliefs about the persistence of PM. Included in this report is the first published case of voluntary PM with objective tinnitus. ( info) |
8/717. Myoclonic disorders of spinal origin. Data in the literature on spinal myoclonic disorders are still scanty; little has been done to ensure an adequate classification; little is known about the pathophysiology of these disorders. Three patients with spinal myoclonic jerks are described, with detailed reference to electromyographic findings. On the basis of the case reports so far available, a classification into five subgroups is suggested of spinal myoclonic jerks: 1) after cord injuries; 2) associated with intramedullary cord tumours; 3) associated with intramedullary or extramedullary cysts; 4) associated with radiculomyelitis or myelopathy; 5) associated with affections of the alpha motoneurons. A number of hypotheses on the pathogenesis of this disorder are briefly discussed: peripheral or intraspinal sprouting, degeneration of alpha motoneurons or interneurons, reduction of the dendritic tree size, and involvement of the gamma system. ( info) |
9/717. melatonin treatment of non-epileptic myoclonus in children. Oral melatonin (MLT) has been used by our Vancouver research group in the treatment of paediatric sleep disorders since 1991; slightly over 200 children, mainly with multiple disabilities, who frequently had seizures, have been treated. Three children with markedly delayed sleep onset due to recurring myoclonus were also referred for MLT treatment: two had non-epileptic, and one had epileptic and non-epileptic myoclonus. Low doses of oral MLT (3 to 5 mg) unexpectedly abolished their myoclonus and allowed them to sleep. There were no adverse effects. It appears that certain types of myoclonus, which might be resistant to conventional anticonvulsant medications, may respond to MLT but the mechanism of action is unclear. Further research on this novel treatment is urgently needed. ( info) |
10/717. A case of epileptic negative myoclonus: therapeutic considerations. This study presents a patient with epileptic negative myoclonus who showed interictal focal epileptic discharges in the centrotemporal region. The patient's seizures were exacerbated by carbamazepine, zonisamide, and valproate, but completely controlled by ethosuximide, and were suggested to have some relation with thalamocortical oscillation mechanisms. ethosuximide is supposed to be a drug of worth to try to use in epileptic negative myoclonus patients with centrotemporal spike foci. ( info) |