A Retrospective Study of Magnetic Resonance Imaging Findings in Acute Encephalitis Syndrome.

Abstract

Introduction: MRI is the imaging modality of choice to investigate acute encephalitis and is recommended in all patients as soon as possible in whom diagnosis is uncertain. This study aimed to study the pattern of brain involvement in MRI in patients with acute encephalitis syndrome and to correlate the findings with clinical and laboratory data.

Methods: The study was a retrospective hospital record based review conducted at Tribhuvan University Teaching Hospital. MRI and records of patients undergoing MRI for acute encephalitis syndrome during two years duration was studied. Data analysis was done using IBM SPSS 20.0.

Results: A total of 47 MRI were studied among which 11(23.40%) were pediatric and 36(76.59%) were adult population. Edema was the commonest manifestation. Cerebral hemisphere (temporal lobe) was the commonest location involved 34(72.3%). Basal ganglia and thalamus involvement was also fairly common.

Five (26.31%) out of 19 patients had positive Japanese encephalitis, 5(26.31%) had HSV antigen positive serology and in 8(42.10%) no etiology could be found. Posterior fossa and basal ganglia involvement was the most predominant findings in Japanese encephalitis and involvement of medial temporal lobe was seen in all cases of Herpes encephalitis. Fifteen patients had good prognosis: complete recovery or minimal residual deficit, while four patients were either dead or left against medical advice.

Conclusion: Medial temporal lobe involvement was seen in all cases of Herpes encephalitis; and thalamus and basal ganglia involvement was predominant pattern in Japanese encephalitis. Posterior fossa involvement was common probably due to a non-conventional etiological agent.