Summary: Purpose: Positron emission tomography (PET) has proven useful in epilepsy surgery for its ability to identify unilateral temporal hypometabolism (UTH), which is predictive of good surgical outcome. The significance of bilateral temporal hypometabolism (BTH) is not known.Methods: We identified all patients who had marked bilateral reduction in temporal lobe metabolism relative to the cerebellar hemispheres and compared their clinical features and treatment outcomes with those of control patients with UTH.Results: BTH was evident in 10% of PET scans for epilepsy at our institution. We compared these patients with agematched controls with UTH. The BTH patients had a higher percentage of generalized seizures; were more likely to have bilateral, diffuse or extratemporal seizure onsets; and had bilateral or diffuse magnetic resonance imaging (MRI) findings. UTH patients were more likely to have unilateral mesial temporal atrophy on MFU. Even when electrical seizure onsets were well localized, surgical outcomes were markedly worse in these patients than in controls. Medical treatment was also less successful. Social and cognitive functioning was worse in the BTH group. The only death occurred in the group with BTH.Conclusions: Patients with BTH have features distinct from those with UTH and have a worse prognosis for seizure remission after surgery.

Isolated angiitis of the central nervous system (IACNS) is a rare form of vasculitis restricted to the CNS. We report serial MRI findings in a biopsy-proven case of IACNS. MRI showed extensive white matter and subcortical disease. Before specific treatment, neuroimaging showed the development of new lesions corresponding with an overall progressive clinical course of the illness; the post-treatment MRI showed improvement.

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Contiguous spread along perineural and endoneural spaces, that is, perineural tumor extension, in cutaneous squamous cell carcinoma is fairly common. Infrequently, these tumors spread and involve intracranial structures. One consequence of this complication is meningeal carcinomatosis which is underrecognized. Herein described is a patient with recurrent cutaneous squamous cell carcinoma with perineural invasion along the maxillary nerve that was subsequently shown by magnetic resonance imaging to the trigeminal root. The patient initially presented with a cavernous sinus syndrome but despite aggressive treatment, extensive meningeal carcinomatosis and cauda equina dysfunction developed. Awareness of perineural invasion and proper evaluation are crucial. Perineural spread intracranially worsens the prognosis and limits treatment options to palliation.