How Different Are the Patients With Bilateral Hippocampal Sclerosis From the Unilateral Ones Clinically?
OBJECTIVE
There is a lack of knowledge on consecutive patients with epilepsy associated with bilateral hippocampal sclerosis (BHS). We aimed to investigate the differentiating features of BHS in comparison with unilateral HS (UHS).


METHODS
We investigated our database for patients with epilepsy fulfilling the major magnetic resonance imaging criteria for BHS; namely, presence of bilateral atrophy and high signal changes on T2 and FLAIR series in the hippocampi. UHS patients seen in past 2 years were included as the control group. Clinical, EEG, and other laboratory findings, data on treatment response and epilepsy surgery were investigated from their files.


RESULTS
A total of 124 patients (31 with BHS and 93 with UHS; 49 right-sided and 44 left-sided) were included. We found that 16.1% of the BHS and 18.3% of the UHS groups were not drug-refractory. A binary logistic regression analysis performed with significant clinical features disclosed that history of febrile status epilepticus, mental retardation, and status epilepticus were statistically more common in BHS group. Moreover, diagnosis of psychosis established by an experienced psychiatrist and slowing of the EEG background activity were both found significantly more frequent in BHS. 66.67% of the operated BHS patients showed benefit from epilepsy surgery.


CONCLUSIONS
BHS is a heterogeneous group, showing significant differences such as increased frequencies of mental retardation, status epilepticus, febrile status epilepticus and psychosis, in comparison to UHS. In all, 16.1% of the BHS cases showed a benign course similar to the UHS group and some patients with drug-resistant epilepsy may show benefit from epilepsy surgery.
1 Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.|2 School of Medicine, Department of Neurology, Koç University, Istanbul, Turkey.
Ebru Nur
EN
Vanli-Yavuz
1 Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.
Betul
B
Baykan
3 Department of Neuroradiology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.
Serra
S
Sencer
4 Department of Neurosurgery, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.
Altay
A
Sencer
5 Department of Psychiatry, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.
Isin
I
Baral-Kulaksizoglu
1 Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.
Nerses
N
Bebek
1 Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.
Candan
C
Gurses
1 Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.
Aysen
A
Gokyigit
D000328:Adult; D004569:Electroencephalography / Q000379:methods; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis / Q000503:physiopathology*; D006624:Hippocampus / Q000503:physiopathology*; D006801:Humans; D008607:Intellectual Disability / Q000175:diagnosis / Q000503:physiopathology; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D013226:Status Epilepticus / Q000175:diagnosis / Q000503:physiopathology*
bilateral hippocampal sclerosis; epileptic psychosis; febrile status epilepticus; mental retardation; mesial temporal sclerosis; status epilepticus