Faculty Bibliography

Neurosurgical practice requires a solid foundation in the principles and interpretation of the neuro-ophthalmologic examination. In this article, the techniques used in the neuro-ophthalmologic examination to assess visual acuity, ocular motility, visual fields, the pupils, the eyelids, and the fundus are reviewed. An emphasis is placed on those techniques most relevant to neurosurgical practice.

A 36-year-old man presented with spinal myoclonus, ataxia, hearing loss, and unilateral pupillary dilation. MRI demonstrated hemosiderin deposition along the superficial surfaces of the brain, brainstem, cerebellum, and spine. The pupillary changes were localized to the preganglionic oculomotor nerve. In contrast to vasculopathic oculomotor nerve palsies, superficial siderosis may cause selective involvement of the superficially located pupillary fibers

The authors describe five patients with trochlear nerve palsy and MS to characterize this rare association. In two patients, trochlear nerve palsy was the initial clinical manifestation of MS. In the other three patients, this sign occurred after previous neurologic events. MRI did not identify a lesion of the fourth nerve nucleus or fascicle. Ophthalmoplegia resolved within 2 months in four of the five patients. A reason this association is rare is that the fascicular course of the trochlear nerve is exposed to little myelin.

BACKGROUND AND PURPOSE: Magnetization transfer imaging provides information about the structural integrity of macromolecular substances, such as myelin. Our objective was to use this imaging technique and contour plotting to characterize and to define the extent of white matter lesions in multiple sclerosis and traumatic brain injury. METHODS: Magnetization transfer imaging was performed of 30 multiple sclerosis plaques and 10 traumatic white matter lesions. Magnetization transfer ratios (MTRs) were calculated for the lesions, for the normal- or abnormal-appearing surrounding white matter, and for remote normal-appearing white matter. MTR contour plots were constructed about these lesions. RESULTS: The contour plot appearance of MS plaques differed from that of traumatic white matter lesions. There was a gradual increase in MTR values at points at increasing distances from the center of the MS plaques; this was true for those lesions with and without surrounding T2 signal abnormality (halos). In contrast, there was an abrupt transition in MTR values between traumatic lesions and normal-appearing surrounding white matter. Additionally, the size of the MTR abnormality exceeded the size of the T2 signal abnormality for the MS plaques. CONCLUSION: MTR contour plots permit characterization and border definition of white matter lesions. Analysis of the contour plots suggests that MS is a centrifugal process with the lowest MTR within the center of the lesion. In contrast, traumatic white matter injuries are discrete lesions with abrupt transitions between the abnormal lesion and normal brain

Extracorporeal photopheresis is a safe therapy for cutaneous T-cell lymphoma and may have efficacy in certain autoimmune disorders. We performed a randomized, double-blinded, placebo-controlled trial of monthly photopheresis therapy in 16 patients with clinically definite multiple sclerosis (MS). All patients had progressed during the preceding year with entry Expanded Disability Status Scale (EDSS) scores between 3.0 and 7.0. Patients received photopheresis or sham therapy for 1 year and were followed for an additional 6 to 12 months. Patients were clinically evaluated by three disability scales: (1) EDSS; (2) Ambulation index and (3) Scripp's quantitative neurologic assessment. No serious side effects occurred in either group. There were no differences between the photopheresis and sham therapy groups by the disability measures. Additionally, there were no differences in progression of MRI plaque burden or evoked potential latencies. In this limited study, photopheresis was found to be safe but did not significantly alter the course of chronic progressive MS

The relation between obesity and age in children with idiopathic intracranial hypertension (pseudotumor cerebri) has remained uncertain. The authors reviewed the records of 45 consecutive children with newly diagnosed idiopathic intracranial hypertension seen at two medical centers. Forty-three percent of patients aged 3 to 11 years were obese, whereas 81% of those in the 12- to 14-year age group and 91% of those in the 15- to 17-year age group met criteria for obesity (p = 0.01). Younger children with idiopathic intracranial hypertension are less likely to be obese than are older children or adults.

The authors report two patients with testicular cancer who exhibited supranuclear gaze disorders as a manifestation of a paraneoplastic brainstem encephalomyelitis. In the first patient, neuro-ophthalmic dysfunction was accompanied by a prominent limbic encephalitis whereas in the second patient, an unusual, mixed pendular and jerk nystagmus was manifested. Neuroimaging revealed an enhancing hypothalamic mass in the first patient and was negative in the second. Blood from both patients contained an antibody previously reported in a patient with limbic encephalitis and testicular cancer.

We report the MR findings in two patients with clinically and histologically proved Dejerine-Sottas disease. One patient had spinal involvement with multiple thickened and clumped nerve roots of the cauda equina; the second had multiple enlarged and enhancing cranial nerves. Although these findings are not specific for Dejerine-Sottas disease, they are suggestive of the diagnosis, which is further corroborated with history and confirmed with sural nerve biopsy and laboratory studies.