A widower is campaigning to warn women of the dangers of visiting hairdressers after his wife suffered a stroke as she had her hair shampooed.

Malcolm Crabb's wife Pamela was struck down by beauty parlour stroke syndrome after her head was pushed backwards into a sink in September 2000.

Her speech became slurred and her hands became claw-like. Tests revealed that the 51-year-old teacher had suffered a minor stroke.

She never fully recovered, and last week she suffered another stroke and died.

Research suggests that when the head is pushed back it can restrict bloodflow in the neck.

"As she was having her hair washed I could see her face had gone very red," said Mr Crabb, 49, an estate agent. "When she got up she wasn't speaking normally.

"The doctors asked if she had had any neck injuries, but we couldn't think of any. Then they asked if she had had her hair done recently. Now I want to alert others to the dangers. There should be warnings in hairdressing salons about it."

Two British doctors reported in the medical journal The Lancet in 1997 that a 42-year-old woman suffered a stroke after a shampoo. They recommended that the neck be supported with a cushion and not over-extended.

Research on 500 female stroke victims in Japan showed that 30 fell ill after a beauty parlour visit.