Related Experiment Videos
Abnormalities in hippocampi remote from the seizure focus: a T2 relaxometry study
Rod C Scott1, J Helen Cross, David G Gadian
1Neurosciences Unit, Institute of Child Health, University College London, and Great Ormond Street Hospital for Children NHS Trust, UK. rscott@ich.ucl.ac.uk
Brain : a Journal of Neurology
|June 14, 2003
Summary
Hippocampal abnormalities are linked to partial epilepsy, even outside the seizure focus. T2 relaxometry reveals prolonged T2 relaxation times in hippocampi remote from the seizure focus, suggesting ongoing seizure activity causes these changes.
Area of Science:
- Neurology
- Neuroimaging
- Epilepsy Research
Background:
- Partial epilepsy affects children and young adults.
- Hippocampal abnormalities can occur even when the hippocampus is not the primary seizure focus.
- T2 relaxometry is a sensitive MRI technique for detecting subtle hippocampal abnormalities.
Purpose of the Study:
- To investigate hippocampal abnormalities in patients with partial epilepsy using T2 relaxometry.
- To determine if hippocampi not serving as the primary seizure focus exhibit abnormalities.
- To explore the relationship between seizure focus location and hippocampal changes.
Main Methods:
- Utilized T2 relaxometry on MRI scans of 96 children and young adults with partial epilepsy and 27 controls.
- Classified epilepsy patients into three groups: mesial temporal sclerosis with temporal lobe epilepsy (MTS-TLE), lesional temporal lobe epilepsy (l-TLE), and extratemporal epilepsy (ETE).
- Compared T2 relaxation times in hippocampi across patient groups and controls, adjusting for age.
Main Results:
- Significantly prolonged T2 relaxation times were observed in hippocampi remote from the seizure focus in all epilepsy patient groups compared to controls.
- Specific mean T2 prolongation values were: 3.3 ms in non-sclerotic hippocampi of MTS-TLE patients, 4.3 ms in l-TLE patients, and 3.7 ms in ETE patients.
- Sclerotic hippocampi in MTS-TLE patients showed a substantial mean T2 prolongation of 19 ms.
Conclusions:
- Hippocampal abnormalities, indicated by prolonged T2 relaxation times, are present in partial epilepsy, even in regions not initiating seizures.
- The findings suggest that ongoing seizure activity, rather than the specific cause or location of the seizure focus, is likely responsible for these remote hippocampal changes.
- T2 relaxometry is a valuable tool for identifying these subtle, widespread hippocampal abnormalities in epilepsy.