Case Report: Ictal Central Apnea as First and Overlooked Symptom in Temporal Lobe Seizures

Ictal respiratory changes have been mainly described following generalized tonic-clonic seizures and recently considered as a biomarker for the risk of sudden unexpected death in epilepsy (SUDEP). Nonetheless, modification of respiratory pattern can be related also to focal seizures, especially arising from the temporal lobe. Changes in cardiac function such as tachycardia or bradycardia could be often associated. We report a short case series of four patients with temporal lobe epilepsy admitted to our Epilepsy Monitoring Unit (EMU) presenting with an ictal central apnea as the first clinical manifestation of their seizures. None of the patients was aware of the occurrence of respiratory arrest. Age at onset ranged from 15 to 29 years. One patient had seizures with prolonged central apnea accompanied by a significant decrease in Oxygen Saturation. The neuroimaging studies in patient 2 and 4 showed alterations of mesial temporal lobe structures. Recent neurophysiological studies supported the existence of a cortical network involving the limbic system that modulates the downstream control of brainstem respiratory centers. Monitoring for respiratory changes occurring at the onset of focal seizures is warranted for their value in defining the epileptogenic zone and for the assessment of the risk of SUDEP in this subgroup of patients.