Neurological manifestations of hemorrhagic fever with renal syndrome caused by Puumala virus: review of 811 cases.

Eight-hundred eleven case records of patients with hemorrhagic fever with renal syndrome (HFRS) caused by Puumala virus were reviewed, and particular attention was given to data regarding severe neurological manifestations. The most common symptoms were headache (97%), blurred vision (40%), and vomiting (31%); 27% of the patients had all three. Nine patients (1%) had severe neurological manifestations: meningism and cerebral hemorrhage occurred during the first week of illness, whereas epileptiform seizures and urinary bladder paralysis developed during the second week. In terms of the severity of renal failure, as evidenced by maximum serum creatinine levels, there was no difference between patients with or without severe neurological conditions. There was one fatal case due to cerebral hemorrhage; the other patients with severe neurological manifestations clinically recovered and did not have any neurological signs during 6 months of follow-up. HERS caused by Puumala virus, or a variant of it, may be associated with severe, potentially life-threatening neurological complications.