Idiopathic chronic temporal lobe herniation with associated epilepsy

Herniation of parahippocampal gyrus is usually caused by pressure differentials intracranially, and herniation without known risk factors is extremely rare. We describe a patient with a long history of seizures and a remote status epilepticus event. On magnetic resonance imaging, a presumed left temporal lobe tumor was observed. On neurosurgical consultation, the lesion was identified as a chronic mesial temporal lobe herniation. The patient lacked history that would suggest risk of cerebral herniation. Accurately identifying the patient's chronic temporal lobe herniation radiographically likely saved this patient from unnecessary surgery or biopsy and allowed the patient to receive appropriate conservative care.

Automated summary

Herniation of the parahippocampal gyrus is rare without known risk factors and is usually caused by intracranial pressure differentials. This case report discusses a patient with a long history of seizures who was found to have chronic mesial temporal lobe herniation on MRI, despite lacking risk factors for cerebral herniation. Accurate radiographic identification of the condition likely prevented unnecessary surgery or biopsy, allowing the patient to receive appropriate conservative care.