1/16. 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.- - - - - - - - - - ranking = 1keywords = median nerve, median (Clic here for more details about this article) |
2/16. 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 = 0.5keywords = median nerve, median (Clic here for more details about this article) |
3/16. Benign segmental myoclonus: electrophysiological evidence of transient dysfunction in the brainstem.We present a 66-year-old patient with segmental myoclonus evoked by a brainstem infarction. The myoclonus appeared soon after a cerebrovascular accident and it was evident in the soft palate, jaw, neck, shoulders and upper limbs. brain MRI showed infarction in the left pons and left cerebellum. Small amounts of orally administered clonazepam were remarkably effective. Electroencephalogram (EEG) and auditory brainstem response (ABR) were normal. Somatosensory evoked potential (SSEP) revealed delays in P 14 and N19 recorded at C3 by right median nerve stimulation. These findings were normalized in 4 days. Seg-mental myoclonus is thought to be evoked by olivary hypertrophy following cerebrovascular accident in the brainstem and is said to be resistant to medication. The limited involvement of the brainstem in our patient may account for the transient segmental myoclonus. The prognosis for this type of segmental myoclonus is excellent.- - - - - - - - - - ranking = 0.5keywords = median nerve, median (Clic here for more details about this article) |
4/16. Disinhibition of somatosensory and motor cortex in mitochondriopathy without myoclonus.OBJECTIVE: To test electrophysiologically, if patients with mitochondriopathy but without evidence of myocloni have subclinical signs of disinhibition in motor and somatosensory cortices. methods: Two patients were studied and compared with age-matched control groups. RESULTS: In both patients, giant somatosensory evoked potentials after median nerve stimulation and a reduced intracortical inhibition tested by transcranial magnetic stimulation in a paired pulse paradigm indicated a dysfunction of inhibitory circuits in the motor as well as the somatosensory cortex. In addition, the somatosensory evoked 600 Hz activity recorded by magnetoencephalography was abolished. CONCLUSIONS: patients with mitochondriopathy may suffer from a subclinical disturbance of inhibition in the sensorimotor cortex. The loss of 600 Hz activity indicates that these high-frequency oscillations could reflect the activity of inhibitory neurons in the somatosensory cortex.- - - - - - - - - - ranking = 0.5keywords = median nerve, median (Clic here for more details about this article) |
5/16. Complex movement disorders following bilateral paramedian thalamic and bilateral cerebellar infarcts.Complex movement disorders (CMD; including tremor, dystonias, choreoatheosis, and myoclonus) following infarcts in the posterior and posterolateral thalamic nuclei have been reported. This case of a 59-year-old man who developed CMD following bilateral paramedian and bilateral cerebellar infarcts illustrates the lack of anatomic specificity and the diverse pathophysiology which may underlie CMD.- - - - - - - - - - ranking = 0.014959349118808keywords = median (Clic here for more details about this article) |
6/16. myoclonus of peripheral origin: case secondary to a digital nerve lesion.We present a patient with myoclonus of the left hand appearing 1 month after surgical correction of a stenosing tenosynovitis of the thumb. An extensive fibrosis of the external palmar digital nerve was shown, and the successful liberation of this median nerve terminal branch completely and rapidly eliminated the movement disorder.- - - - - - - - - - ranking = 0.5keywords = median nerve, median (Clic here for more details about this article) |
7/16. Unusual CT and MRI findings in palatal myoclonus.A 23-year-old man suffered from palatal myoclonus for 2 years. It had appeared one week after a minor head trauma. MRI and basal cisternography revealed a localized atrophy of the left paramedian part of the medulla, encroached upon the left vertebral artery. clonazepam treatment was beneficial. This particular case is discussed in relation to etiopathogenesis and other causes of palatal myoclonus.- - - - - - - - - - ranking = 0.0029918698237615keywords = median (Clic here for more details about this article) |
8/16. Cortical mechanisms mediating asterixis.We describe a patient with chronic renal failure who suffered multifocal action-induced jerks. electromyography (EMG) recorded the typical silence of asterixis. back-averaging the EEG activity preceding the EMG silent periods in the forearm showed a biphasic wave antedating the asterixis by 23 ms. Somatosensory evoked potentials (SEPs) after median nerve stimulation were pathologically enlarged on both hemispheres. brain-mapping of the biphasic wave preceding asterixis and the giant SEPs indicated a common origin in the sensorimotor cortex. This observation provides further documentation of a cortical origin for some types of asterixis in humans.- - - - - - - - - - ranking = 0.5keywords = median nerve, median (Clic here for more details about this article) |
9/16. Caudal paramedian midbrain syndrome.BACKGROUND: Caudal midbrain lesions involving the entire decussation of the superior cerebellar peduncles have a distinctive clinical picture: bilateral cerebellar ataxia, eye-movement disorders, and palatal myoclonus. Occasionally, unilateral lesions may produce a similar neurologic picture. OBJECTIVE: To define the clinical and radiologic picture of patients with unilateral lower midbrain ischemic lesions of the decussation of the brachium conjunctivum. methods: Five patients with MRI evidence of unilateral paramedian caudal midbrain infarction were investigated, after the acute stage. RESULTS: All patients had bilateral cerebellar dysfunction characterized by dysarthric speech, truncal and gait ataxia, and dysmetric movements of the limbs, which were more pronounced on one side. Ocular movement abnormalities were observed in three cases. A constant MRI finding was a bilateral inferior olivary degeneration, but only one patient displayed a delayed palatal tremor. CONCLUSIONS: A single strategically placed unilateral lesion can cause bilateral dysfunction. In addition, a bilateral cerebellar syndrome can occur with unilateral lesions in the lower midbrain with a wide range of other clinical features.- - - - - - - - - - ranking = 0.014959349118808keywords = median (Clic here for more details about this article) |
10/16. Neuropathologic findings in idiopathic opsoclonus and myoclonus. Their similarity to those in paraneoplastic cerebellar cortical degeneration.The neuropathologic findings in an idiopathic case of the opsoclonus/myoclonus syndrome are reported. Although neurologic dysfunction may have been more widespread, structural lesions were limited to the cerebellum and inferior olives. Severe depletion of purkinje cells with preservation of granular cells was evident throughout the neo- and paleocerebellum; however, groups of Purkinje cells were preserved in the archicerebellum. No abnormalities were evident in the paramedian pontine reticular formation of the caudal pons. inflammation and evidence of anoxic damage were absent. These changes are very similar to those described in paraneoplastic cerebellar cortical degeneration.- - - - - - - - - - ranking = 0.0029918698237615keywords = median (Clic here for more details about this article) |
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