Optimal time of duration of a long-term video-EEG monitoring in paroxysmal events - A retrospective analysis of 282 sessions in 202 patients.

PURPOSE: To find the optimal duration of the long-term video-EEG (LTM) and assess diagnostics utility of LTM in patients with epilepsy and other paroxysmal events in terms of future diagnosis and management.

METHODS: Retrospective analysis of 282 LTMs performed in the last 5 years in our Epilepsy Monitoring Unit (EMU), in 202 consecutive patients. The analysis included demographic data, monitoring time, number and type of paroxysmal events, the time until their onset, influence of LTM result on the diagnosis and future management.

RESULTS: There were 117 women and 85 men, mean age 34.2 years. Mean duration of LTM was 5 days (3-9), with 447 paroxysmal events recorded in 131 (65%) patients. Epileptic seizures were recorded in 82% cases (in 11% associated with PNES). The remaining 18% had either PNES (psychogenic non-epileptic seizures) - 11%, or parasomnias - 7%. Only 15% of epileptic seizures took place within the first 24h of the LTM (53% and 32% on the 2nd and 3rd day, respectively), whereas as many as 62% of PNES did (while only 28% and 10% on the 2nd and 3rd day, respectively). The LTM results changed the diagnosis in 36% of the patients, most frequently in PNES (from 2% to 14%). Altogether, it changed the management in 64% of the patients - particularly with PNES and those who underwent epilepsy surgery.

CONCLUSIONS: LTM should last at least 72h in patients with refractory epilepsy. Most of cases with PNES could be diagnosed after 48h.