1/829. 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. ( info) |
| BACKGROUND: sarcoidosis involves the nervous system about 5% of the time and usually manifests as a granulomatous inflammation of the basal meninges and hypothalamus. Cases which are strictly isolated to the central nervous system occur infrequently; rarely, they may present as an intracranial mass. methods: We present the case of a solitary sarcoid granuloma at the cerebellopontine angle in a 42-year-old female who presented with headache, facial numbness, and hearing loss. RESULTS: A suboccipital craniectomy was performed and the lesion was noted to be grossly adherent to the lower cranial nerves and skull base. The lesion was misdiagnosed as a meningioma with preoperative magnetic resonance imaging and intraoperative histology, and perhaps additional morbidity resulted. CONCLUSION: We present this case in order to demonstrate the importance of differentiating these dural-based lesions and propose that cases of neurosarcoidosis presenting as a solitary granuloma be treated with surgical debulking and immunosuppression. ( info) |
3/829. Contralateral deafness following unilateral suboccipital brain tumor surgery in a patient with large vestibular aqueduct--case report. A 68-year-old female developed contralateral deafness following extirpation of a left cerebellopontine angle epidermoid cyst. Computed tomography showed that large vestibular aqueduct was present. This unusual complication may have been caused by an abrupt pressure change after cerebrospinal fluid release, which was transmitted through the large vestibular aqueduct and resulted in cochlear damage. ( info) |
4/829. Delayed recurrence of cerebellar abscess 20 years after excision of dermoid cyst and sinus. A patient is described who suffered a greatly delayed reappearance of a cerebellar abscess, 20 years after excision, in childhood, of a midline dermoid cyst with associated abscess formation. A similar organism was cultured on both occasions. ( info) |
5/829. Left leg paralysis in a renal transplant. The postoperative course of renal transplant patients is often complicated by opportunistic infection. Up to 4% of posttransplant infections are caused by nocardia species. We present an unusual case of a nocardial spinal cord abscess that caused left leg paralysis. ( info) |
6/829. Vascular changes in tuberculous meningoencephalitis. Our report refers two cases of tuberculous encephalomeningitis which differ in the course and pathological changes. In case 1 blood vessels showed features of peri, endo-, or panvasculites. In some vessels endothelium proliferation leading to the stenosis or obliteration of the vascular lumen was observed. necrosis was an effect of vessels occlusion. In case 2 many fewer vessel were involved in onflammation process. Vascular changes were also less extensive and were observed more rarely. Tuberculous infection often caused less tissue lesions than vascular changes. Different pathological changes probably depend on the type and virulence of Myobacterium tuberculosis and on the host immune response to the infection. ( info) |
7/829. 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. ( info) |
8/829. 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. ( info) |
9/829. Intrameatal aneurysm successfully treated by meatal loop trapping--case report. A 77-year-old female presented with a rare intrameatal aneurysm manifesting as sudden onset of headache, hearing loss, tinnitus, and vertigo associated with subarachnoid hemorrhage. Meatal loop trapping was performed. After surgery, the patient's functions recovered almost completely, probably because of the preservation of the 7th and 8th cranial nerves and the presence of effective collaterals in the area supplied by the anterior inferior cerebellar artery. ( info) |
10/829. Infantile hiv encephalopathy associated with cerebral and cerebellar telangiectases. We describe a paediatric case of hiv encephalopathy associated with cerebral and cerebellar telangiectases. Although immunohistochemistry failed to show hiv in the walls of dilated blood vessels, or in their vicinity, brain capillary telangiectases might be an additional complication indirectly related to paediatric hiv infection. ( info) |