Clinico-pathological factors influencing surgical outcome in drug resistant epilepsy secondary to mesial temporal sclerosis.
BACKGROUND
Mesial temporal sclerosis (MTS) is the most common cause of drug resistant epilepsy amenable for surgical treatment and seizure control.


METHODS
This study analyzed the outcome of patients with MTS following anterior temporal lobectomy and amygdalohippocampectomy (ATL-AH) over 10 years and correlated the electrophysiological and radiological factors with the post operative seizure outcome.


RESULTS
Eighty seven patients were included in the study. Sixty seven (77.2%) patients had an Engel Class 1 outcome, 9 (11.4%) had Class 2 outcome. Engel's class 1 outcome was achieved in 89.9% at 1 year, while it reduced slightly to 81.9% at 2 years and 76.2% at 5 year follow up. Seventy seven (88.5%) patients had evidence of hippocampal sclerosis on histopathology. Dual pathology was observed in 19 of 77 specimens with hippocampal sclerosis, but did not influence the outcome. Factors associated with an unfavorable outcome included male gender (p=0.04), and a higher frequency of pre-operative seizures (p=0.005), whereas the presence of febrile seizures (p=0.048) and loss of hippocampal neurons in CA4 region on histopathology (p=0.040) were associated with favorable outcome. The effect of CA4 loss on outcome is probably influenced by neuronal loss in other subfields as well since isolated CA4 loss was rare. Abnormal post operative EEG at the end of 1 week was found to be a significant factor predicting unfavorable outcome (p=0.005). On multivariate analysis, the pre-operative seizure frequency was the only significant factor affecting outcome.


CONCLUSIONS
The present study observed excellent seizure free outcome in a carefully selected cohort of patients with MTS with refractory epilepsy. The presence of dual pathology did not influence the outcome.
Department of Neurosurgery, NIMHANS, Bengaluru, India.
B V
BV
Savitr Sastri
Department of Neurosurgery, NIMHANS, Bengaluru, India.
A
A
Arivazhagan
Department of Neurology, NIMHANS, Bengaluru, India.
Sanjib
S
Sinha
Department of Neuropathology, NIMHANS, Bengaluru, India.
Anita
A
Mahadevan
Department of Neuroimaging and Interventional Radiology, NIMHANS, Bengaluru, India.
R D
RD
Bharath
Department of Neuroimaging and Interventional Radiology, NIMHANS, Bengaluru, India.
J
J
Saini
Department of Clinical Psychology, NIMHANS, Bangalore, India.
R
R
Jamuna
Department of Clinical Psychology, NIMHANS, Bangalore, India.
J Keshav
JK
Kumar
Department of Clinical Psychology, NIMHANS, Bangalore, India.
S L
SL
Rao
Department of Neurosurgery, NIMHANS, Bengaluru, India.
B A
BA
Chandramouli
Department of Neuropathology, NIMHANS, Bengaluru, India.
S K
SK
Shankar
Department of Neurology, NIMHANS, Bengaluru, India. Electronic address: drpsatishchandra@yahoo.com.
P
P
Satishchandra
D000293:Adolescent; D000328:Adult; D038481:Anterior Temporal Lobectomy / Q000379:methods*; D002648:Child; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000150:complications / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D007382:Intermediate Filaments / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D012189:Retrospective Studies; D016708:Synaptophysin / Q000378:metabolism; D016896:Treatment Outcome; D014402:Tuberous Sclerosis / Q000150:complications; D055815:Young Adult
D016708:Synaptophysin; D010751:Phosphopyruvate Hydratase
Dual pathology; Epilepsy surgery; Hippocampal sclerosis; Outcome; Pathology; Temporal lobe epilepsy