Rasmussen encephalitis

Case contributed by Dr Nadun Madushanka Vithanage


Break through seizures of known patient who had seizure episodes. Patient was treated for meningoencephalitis at 2 years.

Patient Data

Age: 5 years
Gender: Male

MRI BRAIN done at 5 years

There is unilateral cortical atrophy of the right cerebral hemisphere with exvacuo dilatation of the ipsilateral lateral ventricle.

Juxta cortical and periventricular T2 and FLAIR hyper intensities are seen in the affected hemisphere. 

And also there are left periventricular T2 and FLAIR hyper intensities

No diffusion restriction

No gyral enhancement 

No blooming on SWI to suggest calcification

No significant calvarial thickening 


MRI BRAIN images at 2 years (In the initial presentation with meningoencephalitis)

There are FLAIR hyper-intensities at the right frontal, parietal and occipital lobes with involvement of both grey and white matter. Changes are not confined to a vascular territory. Diffusion restriction is evident. There is mass effect evidenced by sulcal effacement and compression of right lateral ventricle and mild midline shift to left.

There are FLAIR hyper-intensities in the left periventricular white matter. No diffusion restriction.

MRA is normal.




Case Discussion

Unilateral cortical atrophy, hyper intense areas in the affected hemisphere without gyral enhancement is key feature in this case. And history of meningo-encephalitis , age of the patient  supports Rasmussen encephalitis. And these features are compatible with Rasmussen encephalitis(chronic focal encephalitis)

How ever left periventricular T2 and FLAIR hyper intensities are rare finding in Rasmussen encephalitis. And these changes are there in the previous MRI done at 2 years of age. This is probably complications of meningo encephalitis . Because secondary CNS vasculitis is a known complication of meningoencephalitis. 

EEG shows sleep background showed asymmetrical and slightly disorganized theca and delta rhythm. Intermittent focal sharp waves were seen in right centro-temporal region. Impression was abnormal background and epileptogenic zone in R/ Centro temporal region.

Main differential diagnosis of this case Dyke-Davidoff-Masson syndrome. However in this patient there is no significant calvarial thickening, dilatation of mastoid air cells or elevation of petrous ridge to support Dyke-Davidoff-Masson syndrome.

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Case information

rID: 80193
Published: 23rd Jul 2020
Last edited: 24th Jul 2020
Inclusion in quiz mode: Included
Institution: National Hospital Kandy, Sri Lanka.

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