Date post: | 14-Aug-2015 |
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Health & Medicine |
Upload: | mohamed-shaaban |
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• Epilepsy is a chronic, neurologic disorder
characterized by spontaneous, recurrent
seizures.
• Seizures are caused by excessive and
abnormal electrical discharges from the
cortical neurons.
• Generalized.
• Partial.
• Identify underlying structural
abnormalities that require specific
treatment.
HippocampusHippocampus
HippocampusHippocampus
HippocampusHippocampus
HippocampusHippocampus
HippocampusHippocampus
HippocampusHippocampus
HippocampusHippocampus
HippocampusHippocampus
HippocampusHippocampus
HippocampusHippocampus
HippocampusHippocampus
The Hippocampal Formation Consists
Of The Hippocampus, The Dentate
Gyrus and The Subiculum.
HippocampusHippocampus
1. Essential Role In The Formation Of
New Memories.
2. Storing And Processing Spatial Information.
• Hippocampal sclerosis is the most
common epileptogenic substrate
seen.
• Initial precipitating injury, usually
before the age of 5 years.
• Hippocampal sclerosis is
characterized by neuronal loss and
gliosis.
• Hippocampal Sclerosis.
• Mesial Temporal Sclerosis.
1. Unilateral Diffuse Hippocampal Sclerosis.
2. Unilateral Anterior Hippocampal
Sclerosis.
3. Bilateral Diffuse Hippocampal Sclerosis.
1. FLAIR.
2. T1W-IR.
3. T2W.
CORONAL
1-3 mm. Slice Thickness
CORONAL AXIAL
1. Qualitative.
2. Quantitative.
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.
Qualitative
Qualitative
Atrophy And Abnormal T2 Signal
Qualitative
Qualitative
Qualitative
Qualitative
Qualitative
Quantitative
1. Hippocampal Volumetry.
2. HCT2 Measurement.
3. Diffusion-weighted Imaging
(DWI)
Quantitative
1. Hippocampal Volumetry.
2. HCT2 Measurement.
3. Diffusion-weighted Imaging
(DWI)
Quantitative1. Hippocampal Volumetry.
Quantitative1. Hippocampal Volumetry.
Quantitative
2. Hippocampal (HC) T2 Mapping.
Quantitative
3. Diffusion-Weighted Imaging
(DWI)
SPECT
1. Diffuse.
2. Focal Cortical Dysplasia (FCD).
Focal developmental anomalies of cortical structure Focal developmental anomalies of cortical structure
characterized histologically by cortical dyslamination characterized histologically by cortical dyslamination
and the presence of abnormal giant neurons and the presence of abnormal giant neurons
throughout the affected cortex and adjacent white throughout the affected cortex and adjacent white
matter, accompanied in many cases by grotesquely matter, accompanied in many cases by grotesquely
shaped balloon cells of uncertain lineage.shaped balloon cells of uncertain lineage.
1.1. Disorganization of cortical layers.Disorganization of cortical layers.
2.2. Heterotpoic cortical cell within the adjacent white Heterotpoic cortical cell within the adjacent white
matter.matter.
3.3. Myelination defects in the related nerve fibres.Myelination defects in the related nerve fibres.
ClassificationClassification Characteristics
• Architectural dysplasia oHeterotopic neurons in white matteroDerangement of cortical lamination
• Cytoarchitectural dysplasia oHeterotopic neurons in white matteroDerangement of cortical laminationoGiant neurons
• Taylor’s FCD
Without balloon cells oHeterotopic neurons in white matteroDerangement of cortical laminationoGiant neuronsoDysmorphic neurons
With balloon cells oHeterotopic neurons in white matteroDerangement of cortical laminationoGiant neuronsoDysmorphic neuronsoBalloon cells
MR Imaging
Best Sequences:
3D T1 IR
3D T2 SE
FLAIR
1-2 mm slice-1-2 mm slice-
thicknessthickness
MR Imaging
MR Imaging
Focal thickening of the cortex.
Blurring of the gray matter–white matter junction.Signal
intensity changes.
MR Imaging
MR Imaging
Merci