Faculty Bibliography

Two patients with thalamic infarctions presented with vertical gaze palsies. Magnetic resonance imaging (MRI) demonstrated extension of the lesions into the upper midbrain. A common vascular supply to both areas, and the inability of computed tomography (CT) scans to adequately assess posterior fossa structures, necessitate MRI of the mesencephalon in the assessment of all patients with vertical gaze dysfunction. These cases shed further doubt regarding a specific role of the thalamus in control of vertical eye movements.

We report 2 patients who had eyelid retraction and eyelid lag with minimal impairment of vertical gaze. In both patients, magnetic resonance imaging demonstrated a circumscribed unilateral lesion immediately rostral and dorsal to the red nucleus involving the lateral periaqueductal gray area. Our clinical and radiological findings support the existence of a premotor eyelid control center in the region of the nucleus of the posterior commissure.

The ocular tilt reaction (OTR) is a triad of head-eye synkinesis composed of head tilt, conjugate ocular torsion in the direction of head tilt, and skew deviation. The OTR represents a normal compensatory response to lateral head tilts and is produced by activation of the utricle of the lowermost ear. A pathological OTR results when otolith activity is unopposed as the result of injury to the opposite utricle or its nerve. Vertical diplopia may be the only symptom of OTR in patients who have undergone surgery involving the vestibuloacoustic nerve. We report a series of patients with OTR after surgery for acoustic neuroma or Meniere's disease. In each patient, the manifesting symptom was vertical diplopia. Bedside neuro-ophthalmological testing readily excluded a brain stem cause for the double vision. We conclude that OTR after vestibuloacoustic surgery is a benign condition with spontaneous resolution of symptoms within several months

OBJECTIVE: A retrospective study was performed to delineate the clinical characteristics of symptomatic unruptured aneurysms. DESIGN: Patient histories, operative reports, and angiograms in 111 patients with 132 unruptured aneurysms were reviewed. SETTING: Tertiary care university hospital. PATIENTS: One hundred eleven patients with 132 unruptured intracranial aneurysms were studied. There were 85 women and 26 men, with a mean age of 51.2 years (age range, 11 to 77 years). Many patients were referred by community neurologists and neurosurgeons for further evaluation and neurosurgical management. RESULTS: Fifty-four symptomatic patients were identified. Group 1 (n = 19; mean aneurysm diameter, 2.1 cm) had acute symptoms: ischemia (n = 7), headache (n = 7), seizure (n = 3), and cranial neuropathy (n = 2). Group 2 (n = 35; mean aneurysm diameter, 2.2 cm) had chronic symptoms attributed to mass effect: headache (n = 18), visual loss (n = 10), pyramidal tract dysfunction (n = 4), and facial pain (n = 3). Group 3 (n = 57; mean aneurysm diameter, 1.1 cm) had asymptomatic aneurysms. CONCLUSIONS: Acute severe headache, comparable to subarachnoid hemorrhage headache, but without nuchal rigidity, was associated with the following mechanisms: aneurysm thrombosis, localized meningeal inflammation, and unexplained. Unruptured aneurysms may be misdiagnosed as optic neuritis or migraine, or serve as a nidus for cerebral thromboembolic events. Internal carotid artery and posterior circulation aneurysms were more likely to cause focal symptoms from mass effect than were anterior cerebral artery and middle cerebral artery aneurysms. Weeks to years may elapse before their diagnosis. The absence of subarachnoid blood does not exclude an aneurysm as a cause for acute or chronic neurologic symptoms.

Over a 2-year period, we treated 4 postpartum patients with acute neurologic problems appearing 4 to 9 days after delivery. Three patients either had no proteinuria or edema and therefore did not meet all accepted clinical criteria for the diagnosis of eclampsia. Magnetic resonance imaging (MRI) of the brain in all patients demonstrated high-signal foci most prominent in the parieto-occipital regions and the subcortical white matter. Cerebral angiogram in 2 patients revealed diffuse vasospasm. In 3 patients, MRI abnormalities resolved. MRI and angiographic abnormalities in our patients are identical to those of patients meeting accepted criteria for eclampsia. Our experience suggests that the current criteria for the diagnosis of eclampsia are too stringent, both in terms of clinical picture and days postpartum to cerebral manifestations.

The authors describe a 41-year-old woman with herpes zoster ophthalmicus and extensive intracranial and orbital involvement as documented by MR and pathologically. MR showed all of the lesions that led to the ophthalmoplegia and pseudotumor syndrome, the periaxial infarct of the distal optic nerve, pontine infarcts, and granulomatous angiitis of the meningeal vessels. MR is useful in both detection and monitoring of the disease.

We report a patient who rapidly developed unilateral proptosis and complete ophthalmoplegia following blunt trauma to the orbit. Computed tomography (CT) scan revealed a mass involving the sinuses and orbit with erosion of the cribriform plate. Biopsy of this suspected neoplasm revealed features consistent with allergic Aspergillus sinusitis, but cultures later grew a Bipolaris species. Our review of the literature suggests that when allergic fungal sinusitis involves the orbit, Bipolaris is a more commonly isolated organism than Aspergillus. Additionally, extraocular motility impairment and proptosis occur more frequently than visual loss. Treatment is controversial, but surgical drainage followed by corticosteroids is the most often recommended therapy.

We report on a patient with spontaneous remission of a third-nerve palsy who was subsequently found to have meningeal lymphoma. Initial magnetic resonance images (MRI) showed bilateral enhancement of the third nerves. Follow-up MRI 7 months later, without treatment, showed complete resolution. One year after initial presentation, the patient developed multiple lumbosacral radiculopathies and examination of a nerve root biopsy specimen disclosed a B-cell lymphoma. Serial cerebrospinal fluid analyses over the previous year showed occasional atypical cells, later found to resemble closely the biopsy cell type. We conclude that meningeal lymphoma may have a protracted course, with spontaneous remission of both clinical and neuroimaging findings.

We reviewed the incidence of neurologic complications in 200 consecutive patients with aortic aneurysm or aortic dissection. In this 2-year period, neurologic impairment developed in 18.5% of these patients, and in 10 patients neurologic dysfunction heralded aortic rupture or dissection. Those patients with abnormal neurologic examinations at presentation frequently had aneurysm rupture or dissection and a mortality rate of 54%. Patients with thoracic or thoracoabdominal aneurysms were more likely to have neurologic complications than those with abdominal aneurysms. The most common complications were focal central nervous system ischemia, followed by disorders of consciousness and peripheral nerve complications. In patients who had elective aneurysm resection, female sex, aneurysm location, and intraoperative hypotension were risk factors for focal central nervous system ischemia. We conclude that neurologic complications depend on aneurysmal location, occur at various levels of the nervous system, and frequently develop when the intraoperative mean arterial pressure falls below 55 mm Hg.