Hemiencephalitic presentation of neurosarcoidosis: A case report

Background

Neurosarcoidosis is well recognized as a great imitator, however cerebral neurosarcoidosis is usually characterized by a limited spectrum of radiological features which does not include unilateral encephalitis. Truly unilateral encephalitides have a limited differential diagnosis. Most classically there are the infectious causes, predominantly HSV encephalitis, and the inflammatory causes. Rasmussen's syndrome, more common in children, is reported with presentation in adulthood and anti-MOG antibodies have been reported to cause a unilateral cortical inflammation too. However, most of these present acutely, in contrast to our patient who had a subacute presentation.

Case

We present a case of atypical neurosarcoidosis presenting with a hemiencephalitis. A subacute history of clinical and radiological deterioration is seen. Because the clinico-radiological picture was atypical for neurosarcoidosis a brain biopsy was performed which revealed granulomatous inflammation of the cortex without clear involvement of the meninges or vasculitis. Subsequent treatment included steroids, methotrexate and infliximab.

Conclusions

In conslusion, neurosarcoidosis is a challenging diagnosis because clinical manifestations and imaging findings can be resembled by several other diseases. This case highlights further variation in it's presentation.