There is a rare medical condition called Hair Brushing Syndrome.
(The syndrome means that sufferers have to avoid static electricity, which can shut down their brain. As a result people with this condition cannot wear polyester, or play with balloons or, of course, brush their hair – hence the name. I guess they have to avoid going shopping in department stores too. I don’t know if it’s just me, but I’m always getting little shocks when I take the escalator or grab hold of a handrail, and sometimes I even pass the shock on to innocent passers-by.)