Epilepsy

Epilepsy is a brain disorder in which clusters of cells in the brain fire abnormally, leading to seizures. It affects approximately 30 million people worldwide. Temporal lobe epilepsy (TLE) is a form of epilepsy characterised by seizures that arise from specific regions at the sides of the brain; typically leading to seizures that may impair the patient’s consciousness and occasionally spread to both sides of the brain;  leading to convulsions. Approximately 75% of TLE remains uncontrolled by drug therapy; while 30% of patients fail to have their seizures controlled by surgery. This therapeutic issue may be explained by an ambivalence in the classification of TLE itself - currently separated between cases associated with damage to a specific, ’hippocampal’ region within the brain’s lower side (TLE-MTS) and cases presenting no evidence of such compromise (non-lesional TLE). While the standard magnetic resonance imaging technique employed to diagnose such brain damage has been criticised for its lack of sensitivity, new techniques such as diffusion tensor imaging may very well detect underlying damages previously overlooked in ‘non-lesional’ TLE. In accordance with this necessity for new diagnostic and therapeutic innovations for the disease, our PhD project aims to:

  1. Apply novel diffusion tensor imaging (DTI) techniques in order to compare and contrast the integrity and connectivity of brain fibres running through regions of cortical thinning, reduced white matter integrity, and other morphometric impairment in nl-TLE patients compared to TLE-MTS patients and healthy controls,
  2. Utilize resting-state fMRI (rfMRI) to assess possible differences in the functional brain networks of each participant group;
  3. Use SPECT analysis in order to ascertain potentially divergent levels of brain metabolites in nl-TLE patients compared to TLE-MTS patients and healthy controls,
  4. Employ deterministric tractography in order to assess the neural underpinnings of secondarily-generalized tonic seizures; exploring possible damage to regions of the corpus callosum and other major connectors of the brain’s hemispheres in TLE patients who suffer from such secondary generalization compared to those who do not; and
  5. Apply DTI to assess the potential immediate and long-term neurotoxic effects of seizures upon brain fibres in TLE, with the ultimate aim of contributing significant improvements to the diagnosis, potential prognosis and treatment of an extremely debilitating disorder.


TLE1

This image contrasts the white matter tracts of the uncinate fasciculus (i) a neurologically healthy individual, (i) a seizure-free temporal lobe epilepsy patient and (iii) a temporal lobe epilepsy patient suffering from secondarily-generalized tonic-clonic seizures.

Cortical Thickness

This image show areas of reduced cortical thickness in the superior frontal and pre central gyri in non-lesional temporal lobe epilepsy compared to healthy controls.

White Mater Integrity

This image demonstrates regions of reduced fractional anisotropy (white matter integrity) in non-lesional TLE compared to healthy controls, including:
( A ): The temporal fusiform cortex
( B ): The inferior fronto-occipital fasciculus
( C ): Middle & inferior temporal gyri
( D ): Inferior longitudinal fasciculus.