Mapping of cognitive functions in chronic intractable epilepsy: Role of fMRI.
BACKGROUND
Functional magnetic resonance imaging (fMRI), a non-invasive technique with high spatial resolution and blood oxygen level dependent (BOLD) contrast, has been applied to localize and map cognitive functions in the clinical condition of chronic intractable epilepsy.


OBJECTIVE
fMRI was used to map the language and memory network in patients of chronic intractable epilepsy pre- and post-surgery.


METHODS
After obtaining approval from the institutional ethics committee, six patients with intractable epilepsy with an equal number of age-matched controls were recruited in the study. A 1.5 T MR scanner with 12-channel head coil, integrated with audio-visual fMRI accessories was used. Echo planar imaging sequence was used for BOLD studies. There were two sessions in TLE (pre- and post-surgery).


RESULTS
In TLE patients, BOLD activation increased post-surgery in comparison of pre-surgery in inferior frontal gyrus (IFG), middle frontal gyrus (MFG), and superior temporal gyrus (STG), during semantic lexical, judgment, comprehension, and semantic memory tasks.


CONCLUSIONS
Functional MRI is useful to study the basic concepts related to language and memory lateralization in TLE and guide surgeons for preservation of important brain areas during ATLR. This will help in understanding future directions for the diagnosis and treatment of such disease.
Department of Neurology, All India Institute of Medical Sciences, New Delhi, India.
Kapil
K
Chaudhary
Department of Nuclear Magnetic Resonance, All India Institute of Medical Sciences, New Delhi, India.
S Senthil
SS
Kumaran
Department of Neuro-Surgery, All India Institute of Medical Sciences, New Delhi, India.
Sarat P
SP
Chandra
Department of Clinical Neuro Psychology, All India Institute of Medical Sciences, New Delhi, India.
Ashima Nehra
AN
Wadhawan
Department of Neurology, All India Institute of Medical Sciences, New Delhi, India.
Manjari
M
Tripathi
Cognition; functional magnetic resonance imaging; intractable epilepsy