Case history
Case history
A 62-year-old man presents with pyrexia (37.6°C) and his vital signs are otherwise normal. He is drowsy and disoriented with slurred speech and a Glasgow Coma Scale score of 13. He has weakness of his arm abductor muscles, more pronounced on the right. Kernig's and Brudzinski's signs are both positive. Routine blood testing shows a WBC of 14.6 x 10⁹/L, a CRP of 4 mg/L, a normal erythrocyte sedimentation rate and slightly raised serum transaminases. He had been on a 2-week tour of Eastern European countries with his wife in their camper van. He had not received any pre-travel immunisations. They mostly visited rural areas where, on most evenings, he foraged in nearby woods for mushrooms, while his wife prepared their evening meal. While undressing at night, he twice found a tick attached to his right forearm; he removed it carefully with tweezers. On the day following their return to the UK, he developed an abrupt-onset flu-like illness. He had muscle and joint pains and a temperature of 37.4ºC. He was fatigued and nauseous, but did not vomit. He consulted his doctor and was advised to drink fluids and take over-the-counter analgesia. His initial symptoms persisted for about 5 days. He was then asymptomatic for a week. Over a 12-hour period he had progressive speech disturbance and a declining level of consciousness. He is admitted to hospital where a presumptive diagnosis is made of infective meningoencephalitis. He is started on empirical intravenous antibiotics and aciclovir. CT brain scan on day 2 shows no mass lesion or hydrocephalus. A lumbar puncture is performed. Cerebrospinal fluid (CSF) pressure is raised but the CSF appearance is clear. Analysis reveals moderate pleocytosis with 80 leukocytes/microlitre, a moderately increased protein level of 0.6 g/L, and a glucose level of 2.1 mmol/L. The diagnosis is revised to viral encephalitis. Antibiotics are discontinued. The patient does not experience a significant improvement and, based on the history given by his wife, an IgM-capture ELISA is performed on a stored CSF sample for tick-borne encephalitis-specific IgM antibodies. The test is positive. Aciclovir is stopped and after 8 days of supportive care, the patient improves and is transferred from ICU to a general ward. He is discharged 5 days later, fully conscious and oriented. At outpatients review a month later, he has no physical, psychological, or cognitive sequelae.
Other presentations
Infections with the Far Eastern subtype virus are often monophasic, and generally run a more abrupt course than infections with the Western/European virus subtype.[6] In Far Eastern virus infection, the encephalitic syndrome commonly follows on directly from the fever-myalgia phase, without an intervening period of apparent remission, and with more severe manifestations. The lethality rate is high (20% to 40%), and major sequelae (notably, lower motor neuron paralyses of the proximal muscles of the extremities, trunk, and neck) develop in approximately one half of patients.[6] The European subtype is associated with milder disease.[7]
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