Epilepsy is a chronic neurological disorder characterized by recurrent seizures caused by excessive electrical discharges in the brain. There are two main types - generalized seizures affecting the whole brain, and partial seizures affecting only one area. Diagnostic imaging aims to identify any underlying structural abnormalities in the brain that may be causing the seizures, such as hippocampal sclerosis which is the most common epileptogenic substrate seen. Hippocampal sclerosis involves neuronal loss and scarring in the hippocampus and can be diagnosed on MRI using both qualitative and quantitative analysis.

2. • Epilepsy is a chronic, neurologic disorder
characterized by spontaneous, recurrent
seizures.

3. • Seizures are caused by excessive and
abnormal electrical discharges from the
cortical neurons.

4. • Generalized.
• Partial.

5. • Identify underlying structural
abnormalities that require specific
treatment.

8. HippocampusHippocampus

9. HippocampusHippocampus

10. HippocampusHippocampus

11. HippocampusHippocampus

12. HippocampusHippocampus

13. HippocampusHippocampus

14. HippocampusHippocampus

15. HippocampusHippocampus

16. HippocampusHippocampus

17. HippocampusHippocampus

18. HippocampusHippocampus
The Hippocampal Formation Consists
Of The Hippocampus, The Dentate
Gyrus and The Subiculum.

19. HippocampusHippocampus
1. Essential Role In The Formation Of New
Memories.
2. Storing And Processing Spatial Information.

21. • Hippocampal sclerosis is the most
common epileptogenic substrate
seen.

22. • Initial precipitating injury, usually
before the age of 5 years.

23. • Hippocampal sclerosis is characterized
by neuronal loss and gliosis.

24. • Hippocampal Sclerosis.
• Mesial Temporal Sclerosis.

25. 1. Unilateral Diffuse Hippocampal Sclerosis.
2. Unilateral Anterior Hippocampal
Sclerosis.
3. Bilateral Diffuse Hippocampal Sclerosis.

26. 1. FLAIR.
2. T1W-IR.
3. T2W.
CORONAL
1-3 mm. Slice Thickness

27. CORONALAXIAL

28. 1. Qualitative.
2. Quantitative.

29. Qualitative
• Direct: Atrophy (Decreased Size) and abnormal signal.
• Indirect: Loss of internal architecture, loss of hippocampal head
interdigitations, atrophy of ipsilateral mammilary body and fornix,
dilatation of the ipsilateral temporal horn, volume loss of the
temporal lobe, atrophy of the collateral white matter between the
hippocampus and collateral sulcus and dilatation of the “crab’s
claw” of the Perihippocampal Fissures.

30. Qualitative

31. Qualitative
Atrophy And
Abnormal T2 Signal

32. Qualitative

33. Qualitative

34. Qualitative

35. Qualitative

36. Qualitative

37. Quantitativ
e
1. Hippocampal Volumetry.
2. HCT2 Measurement.
3. Diffusion-weighted Imaging (DWI)

38. Quantitativ
e
1. Hippocampal Volumetry.
2. HCT2 Measurement.
3. Diffusion-weighted Imaging (DWI)

39. Quantitativ
e
1. Hippocampal Volumetry.

40. Quantitativ
e
1. Hippocampal Volumetry.

41. Quantitativ
e
2. Hippocampal (HC) T2 Mapping.

42. Quantitativ
e
3. Diffusion-Weighted Imaging (DWI)

43. SPECT

46. 1. Diffuse.
2. Focal Cortical Dysplasia (FCD).

48. Focal developmental anomalies of cortical structureFocal developmental anomalies of cortical structure
characterized histologically by cortical dyslaminationcharacterized histologically by cortical dyslamination
and the presence of abnormal giant neurons throughoutand the presence of abnormal giant neurons throughout
the affected cortex and adjacent white matter,the affected cortex and adjacent white matter,
accompanied in many cases by grotesquely shapedaccompanied in many cases by grotesquely shaped
balloon cells of uncertain lineage.balloon cells of uncertain lineage.

49. 1.1. Disorganization of cortical layers.Disorganization of cortical layers.
2.2. Heterotpoic cortical cell within the adjacent whiteHeterotpoic cortical cell within the adjacent white
matter.matter.
3.3. Myelination defects in the related nerve fibres.Myelination defects in the related nerve fibres.

50. Classification
Classification Characteristics
• Architectural dysplasia oHeterotopic neurons in white matter
oDerangement of cortical lamination
• Cytoarchitectural dysplasia oHeterotopic neurons in white matter
oDerangement of cortical lamination
oGiant neurons
• Taylor’s FCD
 Without balloon cells oHeterotopic neurons in white matter
oDerangement of cortical lamination
oGiant neurons
oDysmorphic neurons
 With balloon cells oHeterotopic neurons in white matter
oDerangement of cortical lamination
oGiant neurons
oDysmorphic neurons
oBalloon cells

51. MR Imaging
Best Sequences:
 3D T1 IR
 3D T2 SE
 FLAIR
1-2 mm slice-1-2 mm slice-
thicknessthickness

52. MR Imaging

57. MR Imaging
Focal
thickening
of the
cortex.
Blurring of
the gray
matter–
white
matter
junction.
Signal
intensity
changes.

58. MR Imaging

59. MR Imaging

60. Merci