Semiology of the Rare Seizure Subtype Piloerection

Objective: To report piloerection and vasomotor instability as a sole manifestation of partial seizures. Design: Case report. Setting: Inpatient tertiary care center. Patient: A 72-year-old man with acute onset of repetitive autonomic events. Main Outcome Measures: Extensive cardiovascular evaluation, electroencephalographic testing, radiology, laboratory assessment, and frequency of clinical events (seizures). Results: We characterize an uncommon manifestation of right temporal lobe partial seizures, initially thought to be cardiovascular in origin, as pilomotor seizures accompanied by other autonomic phenomena. The ictal electroencephalogram recordings established the diagnosis of right temporal lobe seizures, and head magnetic resonance imaging demonstrated right mesial temporal T2 signal change, enhancement, and subsequent atrophy. The underlying etiology was not uncovered despite an extensive laboratory and radiological evaluation. However, given the history and imaging findings, an infectious or secondary immunological etiology was suspected. Conclusions: Pilomotor events with other transient autonomic features, such as tachycardia and blood pressure fluctuations, may represent localization-related epilepsy. The acute onset of these events accompanied by other autonomic phenomena in the setting of focal magnetic resonance imaging abnormalities within the hippocampal region raises questions concerning pilomotor seizures as well as the differential diagnosis of acute seizure activity in the setting of neuroimaging findings characteristic for limbic encephalitis.