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Post-encephalitis gliosis

Case contributed by Dr Azza Elgendy


Headache and menstrual irregularities. At the age of 10 years, patient had encephalitis and since then suffering from chronic seizures. No focal neurologic deficits.

Patient Data

Age: 3rd decade

Unilateral predominantly, frontal, insular and parietal cortical and subcortical atrophy. There is abnormal bright signals involving the frontal and parietal lobes consistent with encephalomalacia and gliosis. Ex-vacuo dilation of the right ventricular system is also seen. 

Extensive gliosis involving the temporal lobe including the hippocampus with resultant ex-vacuo dilation of the temporal horn of lateral ventricle. The void signals of the right MCA is intact. The right temporal lobe including the hippocampus is atrophied and there is compensatory calvarial thickening, most pronounced at the supraorbital region. 

There is a large intrasellar cystic lesion, inseparable from the pituitary gland. The bright spot is seen.

Case Discussion

The patient doesn't have any prior imaging. She doesn't have any focal neurologic symptoms and absence of the Wallerian degeneration or the crossed cerebellar diaschisis. She has chronic seizures (the right hippocampus and almost all the temporal lobe are replaced by extensive encephalomalacia and gliosis). The anatomical distribution could mimic post-herpetic encephalitis, Rasmussen encephalitis and Dyke-Davidoff-Masson syndrome (DDMS). DDMS is excluded because the patient had the encephalitis at the age of 10 and DDMS is a congenital occlusion of the MCA, here MCA is patent (intact flow void) and the patient doesn't have hemiplegia. Rasmussen encephalitis is a very rare unilateral encephalitis, predominately involving frontal, insular and parietal regions with contralateral cerebellar volume loss (crossed cerebellar diaschisis). Herpetic encephalitis can affect any age group, classically involve limbic system, insula, sub frontal area, and cingulate gyrus. The case was read as post encephalitis gliosis as per patient history. The cystic lesion in the pituitary is not fully assessed due to the lack of contrast and the proper protocol to differentiate Rathke's cleft cyst from different cystic sellar lesions.

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Case information

rID: 34040
Published: 16th Feb 2015
Last edited: 14th Aug 2019
Inclusion in quiz mode: Included

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