Upbeat Nystagmus

The patient, a 36 year old Italian, presented in October 1967, at the age of 27, with acute dizziness and ataxia. He was evaluated in Rome. A pneumoencephalogram showed hydrocephalus, attributed to arachnoiditis, and a ventriculo-atrial shunt was placed. Three months post shunt placement he had a return of dizziness and ataxia accompanied by daily bi-occipital headache, diplopia, clumsiness and weakness of the left arm. In January 1968, he was readmitted and a large tumor of the left cerebellar hemisphere with invasion of the vermis was biopsied. A diagnosis of glioblastoma multiforme was made. He was treated with radiation therapy. Post operatively his major deficits were ocular dysmetria, left limb and gait ataxia. In 1970 he immigrated to the US. In 1971 he was referred to Dr. William Sweet, Chief of Neurosurgery at the Massachusetts General Hospital (MGH) with increasing gait ataxia and oscillopsia. Neurological examination: Cranial nerves intact (apart from the eye movements) Motor strength normal Decreased tone in the left extremities Reflexes 2+ throughout with flexor/plantar responses. Coordination: ataxia left extremities Gait ataxia, Romberg negative. Sensory examination normal. Neuro-ophthalmological examination: Visual acuity 20/20 OU Visual fields and pupils normal Fundus exam showed bilateral optic disc drusen Eye movements: •Upbeat nystagmus in primary gaze, increased on up gaze •Square wave jerks •Horizontal gaze evoked nystagmus left > right •Full vertical gaze •Upbeat nystagmus on upgaze •No nystagmus on downgaze •Pursuit, (horizontal and vertical) smooth to a very slow target, markedly saccadic to a fast target •Convergence normal •Marked saccadic hypermetria Right gaze to center overshoot (hypermetria) taking the eyes almost fully to the left Left gaze to center hypermetria taking the eyes almost fully to the right Upgaze to center hypermetria Downgaze to center hypermetria CT scan: In the region of the vermis and the medial portion of the left hemisphere there was an area of high absorption with contrast enhancement involving the cerebellar vermis and medial left cerebellar hemisphere with an apparent associated cystic component consistent with recurrent tumor. Cerebral Arteriogram: A cerebral arteriogram confirmed a highly vascular tumor of the inferior portion of the midline of the cerebellum, bulging into the fourth ventricle. Pathology: The slides from the original biopsy were obtained from Rome and reviewed by Dr E. P. Richardson, Chief of Neuropathology at the MGH. Diagnosis: A high-grade astrocytoma grade 3-4. Surgical procedure: A posterior fossa craniotomy was performed. To access the tumor, the most inferior aspect of the vermis was split to reach the roof of the 4th ventricle. In so doing, a well demarcated tumor nodule was found extending to both sides of the cerebellum, mostly to the left side. It was possible to separate the superior most aspect of the tumor easily from the 4th ventricle. Several small branches of the posterior inferior cerebellar arteries had to be divided to devascularize the tumor which was then gently dissected away from the floor of the 4th ventricle. At the end, the surgeon felt he had as close to a grossly total removal of the tumor as was possible and no visible tumor was left behind. Post operative status: The patient made a good post-operative recovery and was able to walk with an elbow crutch. He continued to be followed by neurosurgery until he was 66 years of age. During that time he had required a shunt revision on two occasions and therapy for an episode of meningitis/cerebritis. See also: http://content.lib.utah.edu/cdm/ref/collection/ehsl-shw/id/289