Classical type of superficial hemosiderosis presenting with temporal lobe epilepsy

Classical type of superficial hemosiderosis (SH) is subpial hemosiderin deposition mainly affecting the cerebellum, brainstem, and spinal cord, which generally presents with cerebellar ataxia and sensorineural hearing disturbance. We here report a rare case of the classical type of SH presenting with temporal lobe epilepsy and perform a literature review on similar cases.

A 63-year-old man with four episodes of impaired awareness and confusion lasting for around 5 minutes after feeling vague uneasiness, suggesting focal impaired awareness seizure, visited a neurosurgical clinic. T2*-weighted magnetic resonance imaging (MRI) showed hemosiderin deposition on the surface of the cerebellum, brainstem, upper spinal cord, and bases of bilateral frontal and temporal lobes. Neurological examination found mild gait ataxia and anosmia. Audiogram showed sensorineural high-frequency hearing loss. Electroencephalogram showed rhythmic theta activities accompanied by intermittent sharp waves over the right fronto-temporal region during a subclinical seizure episode, which led to the diagnosis of temporal lobe epilepsy. Up-dosing of levetiracetam to 1,500 mg/day brought about a seizure-free status. Gait disturbance, however, gradually deteriorated over the following 6 months. Spinal MRI and myelogram found a dural defect at the T3 level. The 4 mm long defect was surgically closed, which led to the gradual improvement of the gait ataxia.

In this case of the classical type of SH due to a dural defect, temporal lobe epilepsy is presumably caused by the neurotoxicity of decomposed products of hemoglobin impregnated in the temporal lobes.