NEURORADIOLOGY


Case 28 :
Adult with epilepsy. Diagnosis please!

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Fig 1.
Fig 2.

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MRI findings: Coronal T2W and T1W images showing hyperintensity of the left hippocampal gyrus, with evidence of mild atrophy as evidenced by mild dilatation of the ipsilateral temporal horn (on T2WI).

Diagnosis

Mesial Temporal Sclerosis

Discussion

It has been postulated that mesial temporal sclerosis may be related to a complicated delivery, febrile convulsions during childhood, and status epilepticus. These circumstances are believed to cause metabolic disturbances in neurons in the hippocampus, which may disappear and be subsequently replaced by gliosis.

The MR criteria include: increased signal in the hippocampus (which is the most consistent finding), a decreased size of the hippocampus (which is the second most common finding), atrophy of collateral white matter adjacent to the hippocampus, enlargement of the temporal horn, diminished gray-white matter demarcation in the temporal lobe, and reduction in size of the temporal lobe. Coronol T2 weighted images allow for the best visualization of the abnormality. Unilateral dilatation of the hippocampal or choroidal fissure of the temporal horn is a common noramal variant and not necessarily indicaative of hippocampal atrophy.

NetLinks
http://www.vh.org/Providers/TeachingFiles/RCW/052496/052496.html

Dr. Deepak Patkar, MRI Centre, Nanavati Hospital, Mumbai