1/148. hiccup and apparent myoclonus after hydrocodone: review of the opiate-related hiccup and myoclonus literature.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.- - - - - - - - - - ranking = 1keywords = rigidity (Clic here for more details about this article) |
2/148. 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.- - - - - - - - - - ranking = 0.002389451666202keywords = muscle (Clic here for more details about this article) |
3/148. 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.- - - - - - - - - - ranking = 0.001194725833101keywords = muscle (Clic here for more details about this article) |
4/148. Facial reflex myoclonus induced by language: a neuropsychological and neurophysiological study.We studied a 53 year old right-handed patient who presented isolated myoclonus of right facial muscles induced exclusively by language. Twitching significantly hindered speaking and reading performance. MRI and CT-scan revealed no brain lesion. Conventional EEG showed a few spike-waves predominantly in the left hemisphere. Spike-waves increased during drowsiness. An EEG-EMG polygraphic study was performed during stimulation tests which included linguistic tasks and non-verbal/non-linguistic tests. myoclonus was triggered by speaking and writing but not by non-linguistic tasks. The severity of myoclonus was dependent on the complexity of the language task. back-averaging of right facial EMG bursts failed to show a reliable EEG-EMG correlation. However, the facial reflex myoclonus might have originated from the left rolandicopercular cortex, as it was triggered by complex language activities. Findings in this case are compared with those reported for other forms of reflex seizure and myoclonus.- - - - - - - - - - ranking = 0.001194725833101keywords = muscle (Clic here for more details about this article) |
5/148. Disappearance of rhythmic involuntary movements during sleep in a case of olivopontocerebellar atrophy.We report on a 54-year-old woman with an 8 or so year history of olivopontocerebellar atrophy associated with the rhythmic involuntary movements of the left upper and lower limbs, and cervical region. Surface electromyogram of the left upper limb revealed rhythmicity (about 3 Hz) and reciprocity between antagonistic muscles, which disappeared on polysomnography at all sleep stages including rapid eye movement sleep without atonia. These were characterized by the co-existence of rhythmic skeletal myoclonus and parkinsonian tremor. These findings suggest that a disturbance of the striatonigral system as well as the dentato-rubro-olivary circuit may be involved in these movements. It also seems that their fate is dependent on the level of wakefulness and that the ascending reticular activating system also plays a role in the development of these movements.- - - - - - - - - - ranking = 0.001194725833101keywords = muscle (Clic here for more details about this article) |
6/148. Cortical reflex myoclonus studied with cortical electrodes.OBJECTIVE: To study the mechanism of cortical reflex myoclonus. methods: A patient with stimulus sensitive myoclonus of the left foot had an array of subdural electrodes placed over the right sensorimotor cortex. RESULTS: Stimulation through one of the electrodes (contact 13) facilitated leg muscles with the shortest latency and was presumed to lie over the motor cortex. tibial nerve stimulation evoked a potential with the shortest latency 1 cm further posteriorly (contacts 11-12). These contacts were presumed to lie over the sensory cortex. The potential at 11-12 was followed by a much larger potential that reversed polarity at contact 13. back averaging from spontaneous myoclonic jerks showed a cortical premovement potential which reversed polarity at contact 13. The threshold for the motor evoked potential in leg muscles evoked by transcranial magnetic stimulation was lower on the affected side. Electrical stimulation through contact 13 produced cortical potentials that could be recorded at adjacent contacts. The combination of a positive potential followed by a negative potential recurred at approximately 35-40 ms intervals, each positive potential generating a myoclonic jerk. Additional waves resembling I waves accompanied only the first positive potential. Surgical removal of the cortex under electrode 13 abolished the myoclonus. CONCLUSIONS: The myoclonic jerks arose in the motor cortex. We postulate that there is increased excitability or synchronization of the cortical neurons at that site. The spontaneous, peripherally induced and recurrent cortical potentials and myoclonic jerks can occur without participation of the circuitry of the presumed I waves.- - - - - - - - - - ranking = 0.002389451666202keywords = muscle (Clic here for more details about this article) |
7/148. Neuromyotonia, myocloni, sensory neuropathy and cerebellar symptoms in a patient with antibodies to neuronal nucleoproteins (anti-Hu-antibodies).A middle-aged patient presented with subacute muscular stiffness, myocloni of both extremity and facial muscles, gait ataxia and symmetrical distal painful paraesthesias. Electrophysiologically, neuromyotonia was confirmed. High titer anti-Hu antibodies were detected, but no other paraneoplastic antibodies were found. Small-cell lung cancer was diagnosed. Under chemotherapy tumor remission was achieved and, except for minor sensory deficits, neurological symptoms disappeared. This report shows that paraneoplastic syndromes associated with antibodies to neuronal nucleoproteins (anti-Hu antibodies) may be associated with a syndrome including neuromyotonia, sensory neuropathy, cerebellar symptoms and myocloni.- - - - - - - - - - ranking = 0.001194725833101keywords = muscle (Clic here for more details about this article) |
8/148. Localization of a gene for myoclonus-dystonia to chromosome 7q21-q31.Essential myoclonus-dystonia is a neurological condition characterized by myoclonic and dystonic muscle contractions and the absence of other neurological signs or laboratory abnormalities; it is often responsive to alcohol. The disorder may be familial with apparent autosomal dominant inheritance. We report a large kindred with essential familial myoclonus-dystonia and map a locus for the disorder to a 28-cM region of chromosome 7q21-q31.- - - - - - - - - - ranking = 0.001194725833101keywords = muscle (Clic here for more details about this article) |
9/148. Segmental facial myoclonus in moebius syndrome.Moebius syndrome is characterized by sixth and seventh nerve palsy and is usually the result of bilateral hypoplasia or aplasia of the respective brain stem nuclei. There have been no reports of involuntary facial movements associated with this malformative complex. We report on a 6-year-old boy affected by Moebius syndrome with asymmetric involvement and segmental facial myoclonus with onset at age 2 years, affecting the side with partially conserved motility. Clinical presentation included congenital peripheral palsy of the right seventh cranial nerve and left-sided rhythmic rising of the upper lip and eyebrow. Surface-electromyography (EMG) of the left levator labii and frontalis muscles showed rhythmic bursting (duration: 150-450 ms; frequency: 1-3 Hz). Electroencephalographic (EEG)-polygraphic recordings and burst-locked EEG averaging failed to show any consistent EEG activity preceding the EMG bursts. Study of the blink reflex, somatosensory and motor-evoked potentials showed findings consistent with pontine pathology. Segmental facial myoclonus, although extremely rare in children, must be differentiated from several other paroxysmal motor manifestations associated with structural lesions involving the brain stem. Segmental facial myoclonus stem-Structural lesion.- - - - - - - - - - ranking = 0.001194725833101keywords = muscle (Clic here for more details about this article) |
10/148. Postural and action myoclonus in patients with parkinsonian type multiple system atrophy.patients with a parkinsonian syndrome and features of multisystem atrophy (pMSA) may exhibit abnormal movements of the hands and fingers, which are reported in the literature either as "jerky" tremor or myoclonus. We studied clinically and electrophysiologically these movements in 11 consecutive patients with pMSA. No abnormal movements were observed when the patients were at complete rest, except for a characteristic parkinsonian "pill-rolling" tremor in one patient. Abnormal small-amplitude, nonrhythmic movements involving just one or a few fingers, or more rarely the whole hand, were observed in nine patients when holding a posture or at the beginning of an action. Accelerometric recordings showed small-amplitude irregular oscillations which, contrary to those of patients with tremor, had no predominant peak in the Fast Fourier frequency spectrum analysis. Electromyographic recordings in the forearm and hand muscles showed brief jerks of less than 100 ms duration which were synchronous in antagonist muscles of the forearm and alternated with brief periods of silence. Electrical stimulation of the digital nerves evoked consistent reflex responses in the wrist flexor and extensor muscles at a latency of 55.3 /-4.1 ms (range, 50-63 ms). Routine electroencephalographic (EEG) and somatosensory evoked potentials to median nerve stimulation were normal. back-averaging of the EEG activity time-locked to the jerks was performed in two patients with no evidence of abnormal cortical activity. Two patients had episodes of transient respiratory failure related to pneumonia. This caused a long-lasting enhancement of the abnormal hand and finger movements, which became larger and more widespread, with features of posthypoxic myoclonus. We conclude that the abnormal hand and finger movements of patients with pMSA are a form of postural and action myoclonus, and can be described as mini-polymyoclonus.- - - - - - - - - - ranking = 0.003584177499303keywords = muscle (Clic here for more details about this article) |
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