LETTERS TO THE EDITOR In vivo cerebral proton MRS in a case of subacute sclerosing panencephalitis Subacute sclerosing panencephalitis

Subacute sclerosing panencephalitis (SSPE) is a rare encephalopathy caused by persistent defective measles virus in the CNS. Brain lesions may involve all regions of the CNS. The pathophysiological events associated with the disease are characterised by a perivascular infiltration by monocytes and astrocytic proliferation, neuronal degeneration, and demyelination. The exploration of SSPE by brain proton magnetic resonance spectroscopy (MRS) might be of interest to evaluate the extent of the metabolic lesions across the brain. We report here cerebral MRS findings in a 17 year old boy with SSPE. The first symptoms—diYculties at school—appeared at the age of 16. Six months later, abnormal movements occurred. The symptoms progressed rapidly over the next 2 months with myoclonic jerks and behavioural changes. On admission to the neurological pædiatric unit, the patient presented an inappropriate gelastic aVect with tangential speech but without any temporospatial desorientation. An EEG was characterised by high amplitude slow waves recurring periodically every 4–6 seconds. The patient had had a severe measles infection at the age of 6 months and had been vaccinated against measles at the age of 2. A slight increase in protein concentration (0.51 g/l) was found in his CSF. Immunoelectrophoresis of CSF showed an inflammatory process with oligoclonal bands. The diagnosis was confirmed by a considerable increase of specific antimeasles virus antibody in serum and CSF. A decline in clinical status was seen during the 3 weeks in hospital with a vegetative state, decerebrate