In the US, the Pacific Northwest and Rocky Mountain states account for most cases although it has been documented in the southeast. Children are affected more than adults and girls twice as often as boys likely due to hair length. Men are affected more often in adults probably from occupational and recreational exposure. Lower extremity weakness develops 5-6 days after exposure beginning with restlessness, irritability and tingling or numbness of the hands and feet. After 24-48 hours an ascending, bilateral paralysis develops with loss of reflexes.
Severe weakness follows with eventual respiratory paralysis and possible death.
Resolution of symptoms after removal of the tick helps make the diagnosis. Recovery occurs over hours with complete resolution of symptoms within days. Once tick-borne paralysis is suspected it is a simple matter of finding and removing the tick. Ticks as Vectors Ticks act as reservoirs or amplifiers for microorganisms. In the amplifier system, the reservoir is a vertebrate such as a mouse or deer and a tick transmits or amplifies the disease.