Younger adults arriving in hospital emergency rooms after a stroke are sometimes misdiagnosed with a range of conditions including vertigo and migraine headaches, researchers said on Wednesday.

Because the typical stroke victim is age 55 or older, an emergency room's staff may not suspect a stroke when a patient under 45 arrives with telltale symptoms, the researchers said.

They urged doctors to be vigilant for signs of a stroke even if the patient is young, noting the importance of quick treatment to prevent lasting damage.

"Accurate diagnosis of stroke on initial presentation in young adults can reduce the number of patients who have continued paralysis and continued speech problems," Dr. Seemant Chaturvedi of Wayne State University in Detroit, one of the researchers, said in a statement.

"We have seen several young patients who were presented to emergency rooms with stroke-like symptoms within three to six hours of symptom onset, and these patients did not get proper treatment due to misdiagnosis. The first hours are really critical," Chaturvedi added.

As part of a study on misdiagnosis of stroke in younger patients, the researchers focused on how medical teams handled 57 U.S. stroke patients ages 16 to 50.

Of these, eight were incorrectly diagnosed with conditions including vertigo, the sensation of unsteadiness and that one's surroundings are moving. Others were diagnosed with migraine, alcohol intoxication, seizure, an inner ear disorder or other conditions.

Stroke symptoms include sudden numbness or weakness in the face, arms or legs, difficulties with speech or sight, dizziness and loss of balance or coordination, and severe headache.

The misdiagnosed patients were discharged from the hospital only later to be correctly diagnosed with a stroke, the researchers told an American Stroke Association conference.

The clot-busting drug tissue plasminogen activator, or tPA, is the only U.S. government-approved treatment for acute stroke, and must be given within three hours of the onset of symptoms to reduce permanent disability caused by stroke.

Stroke is the No. 3 cause of death and a leading cause of disability in the United States.

"Our study indicates that there is an increasing need for 'young stroke awareness' among emergency room personnel," the researchers wrote.