MRI IN JAPANESE ENCEPHALITIS

We document the MRI features in seven patients with Japanese encephali tis, MRI was carried out on a 1.5 T system within 10-60 days of onset, In all the patients MRI revealed bilateral thalamic lesions, haemorrh agic in five, Signal changes were present in the cerebrum in four pati ents, the midbrain and cerebellum in three each, the pens in two and t he basal ganglia in one. The lesions were haemorrhagic in three of the four patients with lesions in the cortex, two of the three with lesio ns in the midbrain and cerebellum, but the pontine lesions were haemor rhagic in both patients. Spinal cord involvement was seen in one of th e three patients who underwent MRI, In two patients MRI was repeated 3 years after the onset, showing marked reduction in abnormal signal; a nd all the lesions gave low signal on both T1- and T2- weighted images . Bilateral thalamic involvement, especially haemorrhagic, may be cons idered characteristic of Japanese encephalitis, especially in endemic areas.