Hyperacute Seizure 05 - Clinical Case Summary
Hyperacute Seizure 05 - Clinical Case Summary
Hyperacute Seizure 05 - Clinical Case Summary
SummaryHistory
41 yo female with episodes of "weird feelings," staring, unresponsiveness and observed oral automatisms.
Exams Performed
MR T1-w post contrast only; MR Coronal T2-w spin echo and MR FLAIR; MR diffusion
Prior available imaging reports
CT Head is not available
MR T1-w post contrast only
1. Negative post contrast T1 weighted MR for foreign tissue lesion nor post seizure hyperemia.
2. There is asymmetric size (volume) of the hippocampi with the right side appearing larger than normal, and the left side appearing normal or less than normal volume.
MR Coronal T2-w spin echo and MR FLAIR
1. There is increase volume of the right hippocampus without apparent persistent T2-w signal increase consistent with either a mild hyperacute seizure or a seizure in alater acute or subacute post seizure timeframe. These changes are evident mainly in the body, the body-tail transition zone and tail portions of the right hippocampus.
2. There is also abnormality of the left hippocampus. However, it exhibits reduced size and actual focal tissue loss within the hilum. The myelinated tracts (both internal and external) are preserved. These changes in the left hippocampus are consistent with mesial temporal sclerosis (MTS) from concurrent epilepsy. Thus, this case represents the chronic effects from prior repetitive eizures on the left, and evidence of a recent but not hyperacute seizure event affecting the right hippocampus.
3. The MR flair sequence demonstrates isointense signal in the enlarged right hippocampus, but increased hyperintensity in the smaller than normal left hippocampus. The left hippocampus hyperintensity represents gliosis associated with chronic MTS rather than edema.
4. The remainder of the brain is within normal limits.
MR Diffusion (DWI)
1. There is signal increase in both hippocampi on MR diffusion. However, this represents chronic gliosis on the left side associatd with tissue loss from prior seizure events (likely epilepsy) and residual, low grade, tissue edema on the right side. The Bo sequence was positive on both sides, confirming T2-w shine-through, but the basis for these changes are different.
MR Susceptibility (SWI) is not available
MR T1-w post contrast only
1. Negative post contrast T1 weighted MR for foreign tissue lesion nor post seizure hyperemia.
2. There is asymmetric size (volume) of the hippocampi with the right side appearing larger than normal, and the left side appearing normal or less than normal volume.
MR Coronal T2-w spin echo and MR FLAIR
1. There is increase volume of the right hippocampus without apparent persistent T2-w signal increase consistent with either a mild hyperacute seizure or a seizure in alater acute or subacute post seizure timeframe. These changes are evident mainly in the body, the body-tail transition zone and tail portions of the right hippocampus.
2. There is also abnormality of the left hippocampus. However, it exhibits reduced size and actual focal tissue loss within the hilum. The myelinated tracts (both internal and external) are preserved. These changes in the left hippocampus are consistent with mesial temporal sclerosis (MTS) from concurrent epilepsy. Thus, this case represents the chronic effects from prior repetitive eizures on the left, and evidence of a recent but not hyperacute seizure event affecting the right hippocampus.
3. The MR flair sequence demonstrates isointense signal in the enlarged right hippocampus, but increased hyperintensity in the smaller than normal left hippocampus. The left hippocampus hyperintensity represents gliosis associated with chronic MTS rather than edema.
4. The remainder of the brain is within normal limits.
MR Diffusion (DWI)
1. There is signal increase in both hippocampi on MR diffusion. However, this represents chronic gliosis on the left side associatd with tissue loss from prior seizure events (likely epilepsy) and residual, low grade, tissue edema on the right side. The Bo sequence was positive on both sides, confirming T2-w shine-through, but the basis for these changes are different.
MR Susceptibility (SWI) is not available
Overall impression
1. There are bilateral hippocampal abnormalities. On the right there are features of a recent, but not hyperacute, seizure event. The right hippocampus has effacement of all the internal white matter tracts. Although the right hippocampus is larger than expected, the degree of cytogenic edema is minimal. The left hippocampus demonstrates all the features of mesial temporal sclerosis with a contracted, small volume hippocampus with sclerotic increase in MR flair signal. Thus, there is evidence of both prior and recent seizure activity in a patient without a history of epilepsy.
Lessons to be Learned
New seizure activity does not mean that there has not been prior subclinical seizure activity or prior hippocampal damage from prior non seizure event, like Herpes II infection or trauma. Hence, there can be evidence of both acute and subacute or chronic damage in different hippocampi on the same imaging study.