Faculty Bibliography

Two patients developed unilateral occipitotemporal infarcts that produced inferior quadrantic achromatopsia and an accompanying superior quadrantanopia. Magnetic resonance imaging and single-photon emission computed tomographic studies of both patients supported the current view that color vision is encoded in the lingual and fusiform gyri. Although the quadrantic defect in color processing was profound, neither patient was aware of it. Simple bedside testing of patients with superior quadrantanopia may disclose an unrecognized quadrantic achromatopsia.

We examined four patients with dorsolateral pontomedullary lesions and skew deviation, with ocular torsion of varying symmetry. In three patients, the hypotropic eye was excyclodeviated relative to the fellow eye. Observations of these patients, combined with recent evidence, suggest that cyclodeviation is a frequent component of skew deviation and may result from variable involvement of utricular, semicircular canal, and cerebelloocular pathways. Although cyclodeviation is a feature of trochlear-nerve palsies, its presence does not exclude skew deviation and underlying brainstem lesions.

Pregnancy may exacerbate underlying neurologic illness or may precipitate an acute neurologic emergency such as pituitary apoplexy. Care is directed to both mother and fetus in a manner designed to optimize the physiologic stability of both. A 'team approach' is often needed

Spontaneous regression of hematologic malignancies is not uncommon and occurs in a wide variety of lymphomas and leukemias. In contrast, spontaneous remission of neurologic symptoms produced by these tumors is exceedingly rare. We report a patient with central nervous system acute lymphoblastic leukemia who experienced at least one spontaneous remission of papilledema and sixth nerve palsy. This represents, to our knowledge, the first case of spontaneous remission of neuro-ophthalmologic signs in a patient with acute leukemia. We conclude that meningeal leukemia may have a protracted course, and that spontaneous remission of neuro-ophthalmologic findings should not be so readily ascribed to a benign process in a patient with preexisting leukemia.

We present four patients with sarcoidosis of the anterior visual pathways. The first patient presented with unilateral visual loss, a mass lesion at the optic nerve head, and an enlarged orbital optic nerve. The second patient presented with bilateral progressive painless visual loss, associated with optic nerve pallor and visual field loss. In these two patients, optic nerve biopsy was diagnostic of sarcoidosis. The third patient developed optic nerve and chiasmal involvement after sarcoidosis was established by lacrimal gland biopsy. The fourth patient had optic nerve, pulmonary, and lymph node involvement with sarcoidosis. A conjunctival and lung biopsy were diagnostic. Computed tomography and magnetic resonance imaging have greatly facilitated diagnosis of sarcoidosis of the anterior visual pathways. Sarcoidosis of the anterior visual pathways may occur alone or in association with other ocular or systemic manifestations. A conjunctival or lacrimal gland biopsy may be preferable as the initial diagnostic approach. Treatment of patients with this condition may require systemic immunosuppression, in addition to corticosteroids, to prevent permanent visual loss.

A patient with Lyme disease developed an isolated sixth nerve palsy at the end of a 1 month course of oral antibiotics. Magnetic resonance imaging disclosed high-signal abnormality at the left pontomedullary junction, implicating involvement of the distal sixth nerve fascicle. Although facial numbness ensued during a subsequent course of intravenous antibiotics, corticosteroid therapy was associated with prompt improvement of neurologic signs, suggesting an immunologic mechanism for the central nervous system dysfunction.

We report a patient with a third nerve palsy and contralateral eyelid retraction from a thalamic-midbrain infarction. Magnetic resonance imaging confirms that this unusual clinical combination, previously termed 'the plus-minus lid syndrome,' results from a lesion in the region of the nucleus of the posterior commissure with extension to the third nerve fascicle

The authors report a 32-year-old woman who had undergone repair of an occipital encephalocele in infancy and who experienced a 20-year history of progressive hearing loss and intermittent vertigo. After parturition, she developed a rapidly progressive quadriparesis and brain-stem dysfunction associated with persistent intraventricular and subarachnoid hemorrhage. Serial magnetic resonance (MR) images showed progressive deposition of hemosiderin along the surface of the brain, brain stem, and spinal cord, and enhanced thickened membranes at the site of the original encephalocele repair. Posterior fossa exploration disclosed hemorrhagic membranes, which were resected; despite removal of this tissue, the patient deteriorated and died. Postmortem examination confirmed iron-containing pigment along the meninges, cerebral hemispheres, brain stem, spinal cord, and cranial nerves accompanied by atrophy of the superficial cerebellar cortex. It is concluded that superficial siderosis may accompany encephalocele repair. This is believed to be the first report in the literature of superficial siderosis of the central nervous system to correlate in vivo MR images with autopsy results

Single-photon emission computed tomography (SPECT) with 99mTc-hexamethylpropyleneamine oxime (HMPAO) was used to investigate changes in cerebral blood flow in seven patients with cortical visual impairment. Traumatic brain injury (TBI) was the cause of cortical damage in two patients, cerebral ischemia in two patients and carbon monoxide (CO) poisoning, status epilepticus and Alzheimer's Disease (AD) each in three separate patients. The SPECT scans of the seven patients were compared to T2-weighted magnetic resonance image (MRI) scans of the brain to determine the correlation between functional and anatomical findings. In six of the seven patients, the qualitative interpretation of the SPECT studies supported the clinical findings (i.e., the visual field defect) by revealing altered regional cerebral blood flow (rCBF) in the appropriate regions of the visual pathway. MR scans in all of the patients, on the other hand, were either normal or disclosed smaller lesions than those detected by SPECT. We conclude that SPECT may reveal altered rCBF in patients with cortical visual impairment of various etiologies, even when MRI studies are normal or nondiagnostic.