The connectivity-based architecture of the human piriform cortex.

The anatomy of the human piriform cortex (PC) is poorly understood. We used a bimodal connectivity-based-parcellation approach to investigate subregions of the PC and its connectional differentiation from the amygdala. One hundred (55 % female) genetically unrelated subjects from the Human Connectome Project were included. A region of interest (ROI) was delineated bilaterally covering PC and amygdala, and functional and structural connectivity of this ROI with the whole gray matter was computed. Spectral clustering was performed to obtain bilateral parcellations at granularities of k = 2-10 clusters and combined bimodal parcellations were computed. Validity of parcellations was assessed via their mean individual-to-group similarity per adjusted rand index (ARI). Individual-to-group similarity was higher than chance in both modalities and in all clustering solutions. The amygdala was clearly distinguished from PC in structural parcellations, and olfactory amygdala was connectionally more similar to amygdala than to PC. At higher granularities, an anterior and ventrotemporal and a posterior frontal cluster emerged within PC, as well as an additional temporal cluster at their boundary. Functional parcellations also showed a frontal piriform cluster, and similar temporal clusters were observed with less consistency. Results from bimodal parcellations were similar to the structural parcellations. Consistent results were obtained in a validation cohort. Distinction of the human PC from the amygdala, including its olfactory subregions, is possible based on its structural connectivity alone. The canonical fronto-temporal boundary within PC was reproduced in both modalities and with consistency. All obtained parcellations are freely available.

Stiripentol in the treatment of adults with focal epilepsy- a retrospective analysis.

OBJECTIVES: The aim of the present study was to evaluate the safety and efficacy of the add-on treatment of stiripentol (STP) in adult patients with severely pharmacoresistant focal or multifocal epilepsy. METHODS: Data on adult patients treated with STP from March 2007 to July 2020 and with at least one clinical follow-up (FU) were retrospectively reviewed. Data on tolerability, efficacy and concomitant medication were evaluated at baseline, 6 months (5.5 ± 1.6 months (mean ± SD)) and 12 months (13.1 ± 3.9 months (mean ± SD)). RESULTS: Data of 22 patients (54.5% male, mean age 34.4 ± 17.79 years (mean ± SD), including mean duration of epilepsy 17.6 ± 25.5 years (mean ± SD), median seizure frequency 30 ± 20 (median ± MAD) per month, and 63.6% being severely intellectually disabled, with 3 to 18 previous anti-seizure-drugs (ASD), were collected. After 6 months, 72.7% of the patients were still taking STP, and 31% of the patients were responders, including 13% who were seizure-free. The 12-month retention rate was 54.4 %, the response rate was 36.4% and 13.6% of patients were seizure-free at the 12-month FU. Reasons for discontinuation were increased seizure frequency, hyperammonaemia and encephalopathy. CONCLUSION: STP seems to be a useful option in the treatment of patients with severely pharmacoresistant epilepsy. Prospective trials are necessary to examine the efficacy of STP in adult patients with pharmacoresistant focal epilepsy.