Very early research suggested a link between HPS and reduced memory or cognitive impairment. Researchers at the time thought that hantavirus might damage your brain directly.
Recent research suggests that the Puumala virus may affect your central nervous system (CNS). Researchers found that people who developed a mild form of HFRS experienced CNS symptoms such as headache, insomnia, and vertigo. This may be due to the virus damaging people's blood-brain barrier, but this isn't clearly understood.