Faculty Bibliography

A 57-year-old awake man developed central neurogenic hyperventilation associated with a pontine mass. Serum pH reached as high as 7.72 with serum carbon dioxide of 6 torr. Examination of CSF during overbreathing showed that CSF pH was markedly alkaline. Pathologic study showed a well-differentiated pontine astrocytoma. The combination of alkaline CSF and an infiltrating pontine lesion supports a structural, rather than chemical, mechanism for central hyperventilation.

We report three patients who exhibited ophthalmoparesis as an early manifestation of progressive paraneoplastic brainstem encephalitis. In two patients, anti-Hu antibodies were detected, whereas in a third, found at postmortem to have thyroid cancer, no antibodies were identified. Postmortem examination of two patients disclosed extensive gliosis, perivascular inflammation, and cell loss in the midbrain and pontine tegmentum. In one of these patients, there was selective neuronal loss within the third, fourth, and sixth nerve nuclei. We conclude that supranuclear or nuclear ophthalmoparesis may be the initial manifestation of paraneoplastic brainstem encephalitis. Our pathologic data suggest that the ophthalmoparesis may result from selective neuronal death within the brainstem tegmentum and ocular motor nuclei.

Neuroimaging with nuclear medicine techniques permits assessment of brain function by measurement of metabolism or blood flow. Such studies complement the anatomic information derived from computed tomography (CT) or magnetic resonance imaging (MRI). We describe two patients with occipital lesions who were initially diagnosed with functional visual loss. Neither CT scan nor MRI adequately demonstrated the source of visual dysfunction; however, single proton emission tomography (SPECT) scanning in a patient with carbon monoxide poisoning and positron emission tomography (PET) scanning in a patient with post-hypoxic delayed encephalopathy were helpful in confirming the organic substrate of their visual impairment. Functional imaging techniques such as SPECT and PET should be considered in patients with suspected cortical visual loss and normal CT or MR scans.

This article reviews the diagnostic testing used in the evaluation of several common neuro-ophthalmologic entities including optic nerve disease, pseudotumor cerebri, anisocoria, ptosis, and ocular motor palsies. Emphasis is placed on these bedside tests that help to establish the diagnosis of these common clinical problems. The utility of the cocaine and Tensilon (edrophonium chloride) tests as well as the role of neuroimaging in these conditions are reviewed.

OBJECTIVE: Lyme disease (LD) is a tick-borne spirochetal infection with a wide range of neurologic and non-neurologic manifestations. The clinical diversity of LD and limitations in serologic diagnosis often make it difficult to document the diagnosis of neuroborreliosis with certainty. METHODS: We reviewed clinical manifestations in 97 seropositive children with particular attention to neurologic manifestations. Diagnostic criteria used in other case surveys were applied to determine how often a definitive diagnosis of neuroborreliosis could be made in children. RESULTS: Of 69 children who met criteria for LD, 32% (22) had new neurologic signs, 73% (16) of which were accounted for by facial palsy and aseptic meningitis. Five of those with neurologic findings also had erythema migrans (EM), and one had both EM and arthritis. Among those with neurologic involvement, boys outnumbered girls two to one. Neurologic abnormalities resolved spontaneously in five children before their serologic results were known. CONCLUSION: In our series, only 27% of children with neurologic abnormalities due to LD had a history of EM or arthritis. Seropositivity commonly constituted the primary basis for diagnosis of LD. Despite its nonspecificity, seropositivity for LD in children with neurologic symptoms usually signifies active neuroborreliosis.

The ophthalmic, neurologic, and neuro-ophthalmic literature over the past year have included a wide variety of interesting case reports, patient series, and reviews involving eye movement abnormalities. This review highlights some of the more important articles and how they contribute to our understanding, diagnosis, and treatment of these disorders. A few topics will receive particular emphasis. In patients with sixth nerve palsies, botulinum toxin injection of the ipsilateral medial rectus muscle has been advocated. Recent results suggest that this treatment has no beneficial effect in acute sixth nerve palsies, but it may have a role in chronic cases. Two groups of authors, each supplying retrobulbar botulinum toxin injection for patients with acquired nystagmus and debilitating oscillopsia, obtained mixed results. One group of patients was moderately satisfied, whereas in the other group, no patients elected to repeat the treatment because of side effects such as ptosis, diplopia, or discomfort from keratitis. Finally, skew deviation is becoming a more recognized cause of vertical double vision from a central or peripheral basis. Articles published recently showed that cyclodeviation may be seen in skew deviation, and that binocular cyclotorsion distinguishes this motility abnormality from a fourth nerve palsy, which exhibits monocular excyclotorsion.

PURPOSE: To determine if diabetic papillopathy may be associated with optic disk neovascularization and visual loss. METHODS: We examined two young adults with bilateral diabetic papillopathy who had permanent loss of vision associated with rapidly progressive posterior segment neovascularization. RESULTS: Within three months both patients developed florid optic disk neovascularization. This neovascularization was slow to regress despite full panretinal photocoagulation. One patient developed a macular tractional retinal detachment. CONCLUSIONS: Diabetic papillopathy may be associated with rapid progression of diabetic retinopathy and, in particular, optic disk neovascularization. Patients should be monitored for this possibility

Ross' syndrome is a rare peripheral nervous system disorder defined by Adie's tonic pupil, hyporeflexia, and segmental anhidrosis. Injury to postganglionic cholinergic fibers is believed to account for the tonic pupil and sweating disturbance. We report a 47-year-old man found to have Ross' syndrome in combination with a complete postganglionic Horner's syndrome. Pharmacologic and sudomotor tests in this unique patient provide further evidence that Ross' syndrome results from injury to sympathetic and parasympathetic ganglion cells or to their postganglionic projections.