Matteo Martinoni1, Pier Paolo Berti2, Gianluca Marucci3, Guido Rubboli4, Lilia Volpi5, Patrizia Riguzzi5, Federica Marliani6, Francesco Toni6, Francesca Bisulli7, Paolo Tinuper7, Roberto Michelucci5, Agostino Baruzzi7, Marco Giulioni2. 1. IRCCS Institute of Neurological Science of Bologna, Division of Neurosurgery, Bellaria Hospital, Bologna, Italy. Electronic address: matteo.martinoni@gmail.com. 2. IRCCS Institute of Neurological Science of Bologna, Division of Neurosurgery, Bellaria Hospital, Bologna, Italy. 3. Section of Pathology, "M. Malpighi," Bellaria Hospital, Azienda USL-IRCCS Institute of Neurological Sciences, Bologna, Italy. 4. IRCCS Institute of Neurological Science of Bologna, Division of Neurology, Bellaria Hospital, Bologna, Italy; Danish Epilepsy Centre, Dianalund, Denmark. 5. IRCCS Institute of Neurological Science of Bologna, Division of Neurology, Bellaria Hospital, Bologna, Italy. 6. IRCCS Institute of Neurological Science of Bologna, Division of Neuroradiology, Bellaria Hospital, Bologna, Italy. 7. IRCCS Institute of Neurological Science of Bologna, Division of Neurology, Bellaria Hospital, Bologna, Italy; Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.
Abstract
BACKGROUND: Hippocampal sclerosis (HS) is the most common cause of drug-resistant medial temporal lobe epilepsy (MTLE). Structural abnormalities such as HS, granule cell pathology (GCP), and focal cortical dysplasia (FCD) have been classified histopathologically, possibly allowing a more accurate assessment of prognostic seizure and neuropsychologic outcomes. We correlated seizure outcome with comprehensive temporal lobe pathologic findings, identified according to the most recent classification systems of HS, GCP, and FCD. METHODS: All the 83 patients who underwent anterior temporal lobectomy (ATL) for drug-resistant MTLE and with a proven diagnosis of HS between April 2001 and May 2014 were collected. Patients were divided in 2 main groups: 1) isolated HS with/without GCP (HS +/- GCP); and 2) HS associated with FCD with/without GCP (HS+FCD +/- GCP). Patients were followed up at least 1 year, and seizure outcome was reported in accordance with Engel classification. RESULTS: Group I: HS +/- GCP: Statistical analysis confirmed a better outcome in HS + GCP patients than in HS-no GCP (P < 0.05). Moreover, a better outcome for the patients affected by GCP type I was observed (P < 0.05). Group II: HS+FCD +/- GCP: Patients with HS variant type I presented a better seizure outcome than the patients with HS type II (Engel class IA HS type I vs. type II: 69% vs. 40%). CONCLUSIONS: A pathology-based approach to epilepsy surgery might improve the interpretation of the results, could predict which cases will enjoy a better seizure outcome, and could help to the comprehension of the causes of failures.
BACKGROUND:Hippocampal sclerosis (HS) is the most common cause of drug-resistant medial temporal lobe epilepsy (MTLE). Structural abnormalities such as HS, granule cell pathology (GCP), and focal cortical dysplasia (FCD) have been classified histopathologically, possibly allowing a more accurate assessment of prognostic seizure and neuropsychologic outcomes. We correlated seizure outcome with comprehensive temporal lobe pathologic findings, identified according to the most recent classification systems of HS, GCP, and FCD. METHODS: All the 83 patients who underwent anterior temporal lobectomy (ATL) for drug-resistant MTLE and with a proven diagnosis of HS between April 2001 and May 2014 were collected. Patients were divided in 2 main groups: 1) isolated HS with/without GCP (HS +/- GCP); and 2) HS associated with FCD with/without GCP (HS+FCD +/- GCP). Patients were followed up at least 1 year, and seizure outcome was reported in accordance with Engel classification. RESULTS: Group I: HS +/- GCP: Statistical analysis confirmed a better outcome in HS + GCP patients than in HS-no GCP (P < 0.05). Moreover, a better outcome for the patients affected by GCP type I was observed (P < 0.05). Group II: HS+FCD +/- GCP: Patients with HS variant type I presented a better seizure outcome than the patients with HS type II (Engel class IA HS type I vs. type II: 69% vs. 40%). CONCLUSIONS: A pathology-based approach to epilepsy surgery might improve the interpretation of the results, could predict which cases will enjoy a better seizure outcome, and could help to the comprehension of the causes of failures.