FLAVIVIRUS MENINGO-ENCEPHALO-MYELO-RADICU LITIS - RESPIRATORY-FAILUREAND BI-BRACHIAL AMYOTROPHY

3 patients developed rapid onset of fever and nuchal stiffness. Paresi s of brachial muscles occurred within 4 days and all patients had resp iratory failure that needed mechanical ventilation. At the peak of the disease there were bilateral asymmetrical severe atrophy of brachial, shoulder and neck muscles, cranial nerve pareses and absent or weak d eep reflexes in the upper extremities. CSF analyses showed sterile lym phocytic pleocytosis. In 2 cases the patients suffered a tick bite in Switzerland and the third was probably bitten by an insect while openi ng a package received from Indonesia. Patients had rapid defervescence and serological tests were found to be highly positive for IgM and th en IgG ELISA FSME (Fruhsommer-Menin-goenzephalitis). The patients were ventilated for 2 to 5 weeks before a progressive improvement was seen . However, on follow-up at 12, 18 and 30 months respectively, proximal muscles were still atrophied and quite weak. Our cases underline that : (1) FSME-ELISA results may cross-react with the Japanese and Central European encephalitis virus species; (2) Flaviviruses do induce unusu al and preferential long-term paralysis of the upper extremities simul ating poliomyelitis; (3) in the 2 patients studied electrophysiologica lly, there were signs of axonal reinnervation not seen in lower motor neuron syndrome which were important for reinnervation to permit progr essive, but late, motor improvement; (4) there is no evidence of exten sion of the endemic foci of tickborne encephalitis in Switzerland.