Seizure, Vol. 9, No. 5. (July 2000), pp. 323-327.
Near infrared spectroscopy (NIRS) is a noninvasive method for bedside measurement of cerebral oxygenation (SaO2). The purpose of this study was to establish differences inSaO2 for complex partial seizures (CPS) and rapidly secondarily generalized CPS (RCPS). We studied eight adults with medically refractory epilepsy undergoing evaluation for temporal lobectomy. We continually measured cerebral SaO2via a Somanetic Invos 3100a cerebral oximeter, pre-ictal (5 minutes), ictal, immediate (30 seconds) post-ictal, and late post-ictal (5 minutes after ictus). Seventeen seizures (12 CPS, four RCPS and one subclinical) were recorded in eight patients. The percentage change in cerebral SaO2from pre-ictal to ictal periods was derived. Cerebral SaO2increased (percentage change, mean: 16.6, SD: 13.9) for CPS and decreased (percentage change, mean: 51.1, SD: 18.1) for RCPS. No change in cerebral oximetry was recorded for the subclinical seizure. Post-ictal (immediate and late) increase in cerebral SaO2was seen for 11 of the 17 seizures (nine CPS and two RCPS). Peripheral SaO2rose greater than 93% for all CPS and the subclinical seizure, but decreased between 78 and 84% during RCPS. These results suggest NIRS distinguishes cerebral SaO2patterns between CPS and RCPS. The decrease in peripheral SaO2, however, may account for the decrease in cerebral SaO2seen in generalized seizures.
