Abstracts

The present study investigates the correlation between clinical characteristics of patients from video-EEG (VEEG) recorded supplementary sensory-motor area (SSMA) seizures and SISCOM analysis. We retrospectivy reviewed video-tapes from patients who had undergone SISCOM during presurgical evaluation. In patients with SSMA seizures we evaluated sequences in seizure semiology and ictal SPECT activation in the SSMA region. SISCOM analysis was performed using Analyze and home made software where interictal and ictal images were coregistered, normalized, subtracted and coregistered with MRI. The standard deviation of the ictal hyperperfusion was measured in each hemisphere and the hemisphere with the least standard deviation was used as the normal reference. Using correction for mass significance according to Bonferroni, hyperperfusions exceeding 3.5 SD were considered significant. The levels and anatomical locations of ictal hyperperfusions within the SSMA region were identified in addition to the global hyperperfusions in each case. From 45 consecutive patients who were analyzed using SISCOM, seven patients had most pronounced semiological features characteristic for SSMA activation. Only one patient had a preceding aura, no sequences in seizure evolution was seen in the remaining six patients. Two out of seven patients showed significant hyperperfusions in the SSMA region (4,0 and 4,1 SD); four patients showed hyperperfusion between 2,3 and 3.2 SD; and one patient had no detectable medial hot spot. All five patients with no, or non-significant, SSMA hotspots had hyperperfusions in other brain regions that did not correlate with SSMA seizure semiology. In two of these patients hyperperfusions in the occipital or temporo-parietal region correlated with the ictal onset zone at invasive recordings. In the patient with no detectable hyperperfusion in the SSMA region the epileptogenic zone was concordant with the occipital hotspot. The ictal onset zone in patients with SSMA seizures may be distinct from the symptomatogenic zone and even lie outside the frontal lobe. SICOM makes a substantial contribution to design subdural grid placement at invasive EEG recording in patients with SSMA seizures.[table1]