Oxygen desaturations triggered by partial seizures: Implications for cardiopulmonary instability in epilepsy
Blum AS, Ives JR, Goldberger AL, Al-Aweel IC, Krishnamurthy KB, Drislane FW, and Schomer DL (2000) Oxygen desaturations triggered by partial seizures: Implications for cardiopulmonary instability in epilepsy. Epilepsia 41:5 536–41.
Abstract: PURPOSE: The occurrence of hypoxemia in adults with partial seizures has not been systematically explored. Our aim was to study in detail the temporal dynamics of this specific type of ictal-associated hypoxemia. METHODS: During long-term video/EEG monitoring (LTM), patients underwent monitoring of oxygen saturation using a digital Spo2 (pulse oximeter) transducer. Six patients (nine seizures) were identified with oxygen desaturations after the onset of partial seizure activity. RESULTS: Complex partial seizures originated from both left and right temporal lobes. Mean seizure duration (+/-SD) was 73 +/- 18 s. Mean Spo2 desaturation duration was 76 +/- 19 s. The onset of oxygen desaturation followed seizure onset with a mean delay of 43 +/- 16 s. Mean (+/-SD) Spo2 nadir was 83 +/- 5% (range, 77-91%), occurring an average of 35 +/- 12 s after the onset of the desaturation. One seizure was associated with prolonged and recurrent Spo2 desaturations. CONCLUSIONS: Partial seizures may be associated with prominent oxygen desaturations. The comparable duration of each seizure and its subsequent desaturation suggests a close mechanistic (possibly causal) relation. Spo2 monitoring provides an added means for seizure detection that may increase LTM yield. These observations also raise the possibility that ictal ventilatory dysfunction could play a role in certain cases of sudden unexpected death in epilepsy in adults with partial seizures.
Keywords: Partial epilepsy, Hypoxemia, Autonomic nervous system, Oxygen desaturation, Sudden death
Context
- Study reporting desaturation during 9 complex partial seizures in 6 patients with pulse oximetry during EEG monitoring. In these TLE patients, desaturation began on average 43 seconds after seizure onset, whereas in Seyal and Bateman a mean delay of 58 s was seen. Mean lowest saturation was 83%. Study was relatively early and did not report on the relation between secondary generalization of a partial seizure and apnea, cf. Bateman et al. and Seyal and Bateman. There was no motor abnormality in the seizures presented, indicating that this is not necessary for the apnea. Waxing and waning pattern of return to stable respiratory pattern is seen after serizures. Heart rate increases were seen in most cases, but EKG abnormalities were not discussed. Apnea-inducing complex partial seizures began in either lobe.