Human autonomic and respiratory responses to direct cortical electrical stimulation

• Autores: Nuria Lacuey
• Directores de la Tesis: Samden D Lhatoo (dir. tes.), José Álvarez Sabin (tut. tes.)
• Lectura: En la Universitat Autònoma de Barcelona ( España ) en 2018
• Idioma: español
• Tribunal Calificador de la Tesis: Albert Selva O'Callaghan (presid.), Philippe Kahane (secret.), Rodrigo Rocamora Zúñiga (voc.)
• Programa de doctorado: Programa de Doctorado en Medicina por la Universidad Autónoma de Barcelona
• Materias:
  • Ciencias médicas
    • Medicina interna
• Enlaces
  • Tesis en acceso abierto en: TDX
• Resumen

  • Patients with epilepsy are well known to be at increased risk of sudden unexpected death. The risk of Sudden Unexpected Death in Epilepsy Patients (SUDEP) ranges from 0.35 to 2.3 per 1000 people per year in community-based populations, to 6.3 to 9.3 in epilepsy surgery candidates. SUDEP’s precise agonal mechanisms are unknown, although recent evidence from the Mortality in Epilepsy Monitoring Units Study (MORTEMUS) points to combined respiratory and cardiovascular collapse driving the fatal event.

    Adverse autonomic nervous system signs are prominent during seizures. Cardiac arrhythmias (bradycardia, asystole, tachyarrhythmias) in approximately 72% of epilepsy patients, post-ictal hypotension, impaired baroreflex sensitivity (potentially compromising cerebral blood flow), enhanced sympathetic outflow, expressed as increased sweating and decreased inter-ictal nocturnal heart rate variability (HRV) are common. Severe alteration of breathing is typically seen in generalized tonic clonic seizures (GTCS). Electroencephalogram (EEG) characteristics, including post-ictal generalized EEG suppression (PGES), are suggestive of high SUDEP-risk, strongly correlate with increased sweating and decreased HRV, and may be accompanied by profound hypotension. Neural mechanisms underlying these patterns need to be defined.

    Epilepsy is a prototypic cortical disorder, where most of the symptoms are produced by the activation or inhibition of specific regions in the cortex. Epileptiform discharges involving a specific area in the brain may induce symptoms related with that area’s functionality. In a similar manner, electrical brain stimulation can be used to map brain functions.

    Although several studies using brain electrical stimulation have suggested the possible role of cortical structures in respiration and autonomic control, reports from some investigators have indicated mixed findings, such that there is no consensus on the precise areas of cortex concerned.

    We aimed to identify cortical sites with roles in respiratory and/or autonomic control and to correlate seizure induced activation or inhibition of these structures to particular peri-ictal autonomic and breathing patterns recognized as potential indices of risk for death. This study describes the role of several limbic/paralimbic structures in respiration and human blood pressure control, and pathomechanisms of breathing and autonomic responses during epileptic seizures, providing insights into mechanisms of failure in SUDEP.