1/667. Disorders in cerebellar ocular motor control. II. Macrosaccadic oscillation. An oculographic, control system and clinico-anatomical analysis.A distinctive cerebellar ocular motor disorder, macrosaccadic oscillation, evolved simultaneously with an acute cerebellar syndrome in 4 patients, 2 with haemorrhagic metastatic melanoma deep in the vermis, a third with a presumed cerebellar haematoma and a fourth with focal demyelinating disease. Ocular oscillations were conjugate, horizontal, symmetrical, occurred in bursts of several seconds duration, had amplitudes of 30 degrees to 50 degrees, and were evoked whenever the patient attempted to shift visual fixation or pursue a moving target. Photo-electric recordings in one patient with tumour defined features of this disorder of saccadic eye movement: (i) oscillation was composed of saccades, (ii) frequency was 2 Hz, (iii) bursts occurred with amplitude first increasing and then decreasing, (iv) intervals between beginnings of saccades averaged 260 ms and (v) eye position did not exhibit systematic drift during the intersaccadic period. These features documented the inreased gain and instability of the visually guided saccadic system. By using increased feed-forward gain in a sampled-data control model we simulated the pattern of macrosaccadic oscillation. We belive that the acute loss of the calibrator function of the cerebellum accounts for the gain abnormality underlying macrosaccadic oscillation.- - - - - - - - - - ranking = 1keywords = b (Clic here for more details about this article) |
2/667. Neuro-ophthalmic, radiographic, and pathologic manifestations of adult-onset alexander disease.A 61-year-old woman had a 3-year history of imbalance. Eye movement studies revealed square-wave jerks, gaze paretic nystagmus, rebound nystagmus, impaired smooth pursuit, impaired optokinetic nystagmus, and abnormal fixation suppression of vestibular nystagmus. A brain magnetic resonance imaging study showed extensive areas of increased signal from the middle cerebellar peduncles and dentate nuclei, which enhanced with gadolinium. Histopathological analysis of a needle biopsy specimen of the left cerebellar peduncle revealed diffuse gliosis in the presence of symmetrically distributed areas of demyelination. There were associated Rosenthal fibers. Clinicopathologic correlation supported a diagnosis of alexander disease. An adult patient with a history of progressive imbalance, ocular motility abnormalities consistent with cerebellar and/or brainstem dysfunction, and diffuse, symmetric hyperintense magnetic resonance imaging signals in brainstem and cerebellar white matter should suggest a diagnosis of adult-onset alexander disease.- - - - - - - - - - ranking = 0.94117647058824keywords = b (Clic here for more details about this article) |
3/667. Hypotonia, congenital nystagmus, ataxia, and abnormal auditory brainstem responses: a report on the first white patient.A white Italian boy, aged 5 years and 8 months, is reported with failure to thrive, hypotonia, truncal ataxia, psychomotor retardation, and congenital horizontal pendular nystagmus with only waves I and II on auditory brainstem responses. Our patient's clinical picture resembles that previously reported in 10 male Oriental patients. He did not manifest spastic diplegia by the age of 2 years, as did the subjects reported in the literature, but knee-jerk hyperreflexia was evident at the most recent clinical reevaluation. Serial brain MRI studies revealed a cystic brain lesion and peritrigonal hyperintensities with no brainstem abnormalities. To date, no other child with a similar syndrome has been described either in europe or in America. The clinical features of this condition are consistent and characteristic. A definitive diagnosis is achieved by demonstrating the absence of all waves following wave I or wave II on auditory brainstem responses as early as 3 months of age. Due to the predominance of males, the occurrence in siblings, the early age at onset, the non-progressive course, and the characteristic auditory brainstem response findings, the syndrome may have a genetic origin and be attributable to a dysgenetic brainstem lesion.- - - - - - - - - - ranking = 1.7058823529412keywords = b (Clic here for more details about this article) |
4/667. A case of the subacute brainstem encephalitis.A case of brainstem encephalitis of undetermined etiology is reported in 66-year-old woman who had a sudden onset of illness with left abducens palsy, nystagmus and ataxia. The symptoms progressed to complete paralysis of eye movements, dysphagia and left hemiparesis with generalized hyperreflexia. Examination of CSF, CT scan and MRI of the brain were normal. The patient died 4 months after onset of disease. Neuropathologic study disclosed in the brainstem numerous perivascular and nodular inflammatory cell infiltrations composed predominantly of lymphocytes T and B. Most intensive inflammation concerned midbrain and pontine tegmentum and to a lesser degree medulla oblongata, pontine nuclei and cerebellar nuclei. basal ganglia, cerebral and cerebellar cortex were unaffected. Neuropathological finding was reminiscent of brainstem encephalitides related to viral infection or to paraneoplastic syndrome. However, HSV-1, EBV, and CMV antigens were not detected by immunohistochemistry, as well as evidences of malignancy were not present in this case.- - - - - - - - - - ranking = 1.1176470588235keywords = b (Clic here for more details about this article) |
5/667. Downbeat nystagmus caused by thiamine deficiency: an unusual presentation of CNS localization of large cell anaplastic CD 30-positive non-Hodgkin's lymphoma.A 24-year-old woman with a large cell anaplastic CD 30-positive T-cell non-Hodgkin's lymphoma (NHL) developed downbeat nystagmus, anisocoria, and oscillopsia. Prior to overt cerebral invasion by NHL, she had a thiamine deficiency with very low thiamine concentrations in the CSF, probably caused by protracted vomiting and increased vitamin B1 consumption by intrathecal tumor cells. We believe that her neurologic symptoms were caused -- at least partly -- by thiamine deficiency, as she reacted well to thiamine supplementation at the beginning of treatment.- - - - - - - - - - ranking = 133.12848472722keywords = deficiency, vitamin, b (Clic here for more details about this article) |
6/667. Acquired convergence-evoked pendular nystagmus in multiple sclerosis.Nystagmus seen only with convergence is unusual. We describe four cases of acquired convergence-evoked pendular nystagmus in patients with multiple sclerosis. The nystagmus was horizontal and asymmetric in all patients. Eye movement recordings in one subject showed a conjugate rather than a convergent-divergent relationship of the phase of movement between the two eyes. All patients had evidence of optic neuropathy and cerebellar dysfunction. Occlusion of either eye during fixation of near targets led to divergent drift of the covered eye and a decrease in nystagmus. Intravenous scopolamine reduced nystagmus in one patient. Base-in prisms alleviated symptoms of oscillopsia at near and improving reading visual acuity. Convergence-evoked pendular nystagmus may be more common than currently appreciated, particularly among patients with multiple sclerosis.- - - - - - - - - - ranking = 0.29411764705882keywords = b (Clic here for more details about this article) |
7/667. Anticonvulsant-induced dyskinesias: a comparison with dyskinesias induced by neuroleptics.anticonvulsants cause dyskinesias more commonly than has been appreciated. Diphenylhydantoin (DPH), carbamazepine, primidone, and phenobarbitone may cause asterixis. DPH, but not other anticonvulsants, may cause orofacial dyskinesias, limb chorea, and dystonia in intoxicated patients. These dyskinesias are similar to those caused by neuroleptic drugs and may be related to dopamine antagonistic properties possessed by DPH.- - - - - - - - - - ranking = 0.76470588235294keywords = b (Clic here for more details about this article) |
8/667. Voluntary nystagmus associated with accommodation spasms.BACKGROUND: Voluntary nystagmus has been recognized as a pendular, rapid, conjugate, primarily horizontal, benign eye movement initiated and maintained by voluntary effort. CASE: A 10-year-old Japanese girl presented with voluntary nystagmus associated with accommodation spasms. Her chief complaints, intermittent blurred vision, headache, and soreness of the eyes, were thought to be related to the voluntary nystagmus and accommodation spasms. FINDINGS: The waveform of the nystagmus appeared pendular, the frequency was 13-15 Hz, and the amplitude was 3-5 degrees. Scanning laser ophthalmoscopic video images clearly demonstrated vertical and torsional components in addition to the horizontal eye movements. Her refraction was unstable, varying between -0.5 diopters (D) and -5.5 D, and the recording of the accommodometer increased to -12.0 D when nystagmus was initiated. CONCLUSIONS: This may be a unique form of voluntary nystagmus that consists of horizontal, vertical, and rotational components associated with accommodation spasms. observation of this patient continues, without any further treatment or examination.- - - - - - - - - - ranking = 0.52941176470588keywords = b (Clic here for more details about this article) |
9/667. Vestibulo-ocular reflex pathways in internuclear ophthalmoplegia.We measured the vestibulo-ocular reflex (VOR) during head impulses in a patient with right-sided internuclear ophthalmoplegia. Head impulses are rapid, passive, high-acceleration, low-amplitude head rotations in the direction of a particular semicircular canal (SCC). Adduction of the right eye was abnormally slow during right lateral SCC head impulses. The VOR during left posterior SCC impulses was severely deficient in both eyes, but the VOR during left anterior SCC impulses was only slightly deficient. We suggest that the vertical vestibulo-ocular pathways in humans are connected in SCC-plane coordinates, not the traditional roll and pitch coordinates, and that anterior SCC signals do not travel exclusively in the medial longitudinal fasciculus.- - - - - - - - - - ranking = 0.52941176470588keywords = b (Clic here for more details about this article) |
10/667. Acute cerebellar ataxia with human parvovirus B19 infection.A 2 year old boy developed acute cerebellar ataxia in association with erythema infectiosum. During the disease, genomic dna and antibodies against human parvovirus B19 were detected in serum but not in cerebrospinal fluid. parvovirus B19 associated acute cerebellar ataxia might occur due to transient vascular reaction in the cerebellum during infection.- - - - - - - - - - ranking = 0.64705882352941keywords = b (Clic here for more details about this article) |
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