A jolt from a stun gun can cause a seizure if the gun is aimed at the head, warns a new report in the Canadian Medical Association Journal.
The case report describes an incident in which an unnamed Ontario police officer was chasing a suspected robber. The officer's partner fired his Taser and accidentally hit the officer.
Two barbs hit the cop in the upper back and head. Within seconds, he collapsed and lost consciousness and fell into a seizure. His eyes rolled upward, he foamed at the mouth and his arms and legs jerked for about one minute.
The officer did not regain full consciousness until he was taken to hospital, where he then felt dazed for several hours. He was later diagnosed with a mild traumatic brain injury and post-concussion syndrome.
It's not clear whether the brain injuries are related to the impact from the Taser shot or the fall to the ground during the seizure.
Until the incident, the officer, in his 30s, had never had a seizure, and had no history of neurological or psychiatric conditions. His medical history was normal and he was not on any medication.
The officer still suffers headaches, anxiety and irritability and has difficulty concentrating 18 months later, although he has not had any seizures since.
Dr. Richard Wennberg and the report's coauthors from Toronto Western Hospital and the University of Toronto say they believe that the Taser current passed to the officer's brain from the dart to the head and probably provoked the seizure directly, "with a mechanism akin to that of seizures induced by electroconvulsive therapy."
The authors say the incident appears to be the first report of a stun gun causing "brain-specific complications."
"Until now, most reports of Taser-related adverse events have understandably concentrated on cardiac complications associated with shots to the chest," write the authors. "[Our report] suggests that seizure should be added to the list of Taser-related adverse events."
Taser International Inc. specifically warns that stun guns should not target the head.
More than 20 Canadians have died after being Tasered. The most prominent recent case involved Polish immigrant Robert Dziekanski, who died in October, 2007, after RCMP officers repeatedly zapped him. His death is now the subject of an inquiry in B.C.
