Faculty Bibliography

A 68-year-old woman with a relatively acute onset of right homonymous hemianopia, Gerstmann syndrome, and global cognitive failure was found to have a lymphocytic pleocytosis and elevated protein on spinal fluid examination and displayed marked meningeal enhancement on magnetic resonance imaging and dilated cortical venules on cerebral angiography. Brain and meningeal biopsy disclosed a necrotizing granulomatous inflammation of small and medium-sized subarachnoid vessels. The brain parenchyma was normal. The angiographic presence of venous abnormalities, the lack of observable angiographic arterial involvement, and the lack of parenchymal pathology are distinctly unusual in granulomatous angiitis of the central nervous system. This case, therefore, extends the pathologic and imaging spectrum of this disorder.

PURPOSE: To elucidate the relationship between anemia and raised intracranial pressure (ICP). DESIGN: Interventional case series. METHODS: Retrospective case series and review of the literature. Only patients with documented papilledema, neuroimaging ruling out a space-occupying lesion, and anemia were included. RESULTS: Five women with confirmed idiopathic intracranial hypertension (IIH) (normal brain magnetic resonance imaging, normal cerebrospinal fluid, elevated intracranial pressure), and one man with presumed IIH (normal head computed tomography [CT], no lumbar puncture) were evaluated. All had bilateral papilledema associated with peripapillary hemorrhages. Two had retinal cotton-wool spots (CWS), and two had preretinal hemorrhages. All had severe iron deficiency anemia, which was discovered at the time of their ocular complaints in five of them. Their symptoms and signs improved dramatically after treatment of the anemia. We found 30 well-documented cases in the English and French literature. Among those, 13 were excluded from our analyses (11 had confounding disorders, and two had cerebral venous thrombosis). In the remaining 17 cases, isolated raised ICP associated with anemia was the most likely diagnosis, although in none of these cases was cerebral venous thrombosis excluded. CONCLUSIONS: Anemia may play a role in the occurrence of raised ICP and papilledema. Although only a few cases in the literature support this association, it may be more common than previously thought. Because most patients are not known to be anemic when papilledema is discovered, we suggest that a complete blood count be obtained in patients with IIH, especially in the absence of known associated factors such as obesity or medications or when treatment aimed at lowering ICP fails to improve the patient's symptoms. The underlying mechanisms remain unknown, but cerebral venous thrombosis should be carefully excluded.

A 23-year-old woman who presented with a branch retinal artery occlusion followed by encephalopathy showed, by brain magnetic resonance imaging, a nonenhancing lesion in the right parietal gray matter with normal diffusion-weighted imaging. Of 64 reported cases of cat-scratch encephalopathy with documented neuroimaging findings, only 12 (18.8%) have had abnormal imaging findings. The abnormalities have included cerebral white matter lesions, basal ganglia and thalamic lesions, and multifocal lesions in immunocompromised patients, but no gray matter lesions similar to those in this patient. The variety of neuroimaging findings supports multiple pathophysiologic mechanisms of central nervous system involvement in this disorder.

We describe unusually extensive contrast enhancement of the dura mater on MRI in a case of dural arteriovenous fistula of the cavernous sinus.