Seizures and breathing: lessons from peri-ictal respiratory disturbances

Breathing can be disrupted by pathological neurological conditions, such as seizures. Ictal respiratory changes comprise central or obstructive apnea, tachypnea, bradypnea, hypoventilation, and hypoxemia. Ictal central apnea (ICA) has been described in association with focal seizures, especially of temporal origin, occurring in 36%-40% of ictal events. Longer ICA duration typically produces hypoxemia, being observed in 33-41% of cases. PCCA (post-convulsive central apnea) has been described in relation to generalized seizures, suggesting brainstem dysfunction following a generalized tonic-clonic seizure (GTC). Growing interest in peri-ictal respiratory disturbances stems from their potential association with sudden unexpected death in epilepsy (SUDEP), the leading cause of mortality in people with epilepsy (PWE). Recent research has highlighted peri-ictal respiratory symptoms as a key factor in SUDEP risk. Given the expanding body of evidence, a comprehensive review is needed to synthesize findings from experimental and clinical studies. Recent intracranial EEG and neuroimaging research has provided new insights into the neurophysiological, structural, and functional correlates of ICA and PCCA, as well as their possible link with SUDEP. This narrative review explores the electroclinical features and pathophysiology of peri-ictal respiratory disturbances, summarizes current neuroimaging data, and discusses their implications for SUDEP risk and potential treatment strategies.