July 29, 2005

Right-brain strokes harder to diagnose

NEW YORK (Reuters Health) - The findings from a study in
Germany suggest that because of differences in symptoms,
strokes affecting the right side of the brain may be
underdiagnosed compared with to those affecting the left side.

Because of the way the brain and body interact, strokes on
the left side of the brain can cause movement problems on the
right side of the body and visa-versa. Still, these signs might
not be obvious, so doctors look for other symptoms as well.

With a left-brain stroke, patients may have difficulty
understanding words or speaking themselves. By contrast, the
symptoms of a right-brain stroke are much more subtle.

"Our study suggests differences in medical attention and
subsequent management between patients with right and left
(brain) stroke," lead author Dr. Christian Foerch, from Johann
Wolfgang Goethe University in Frankfurt, and colleagues note.
Correctly identifying the symptoms of right-brain stroke is
critical for optimal treatment, they add.

One factor that may help explain the difference in stroke
recognition is the symptom scoring sheets doctors use to
evaluate stroke patients. Many of these sheets are simply
better suited to detecting the symptoms of a left-brain stroke
rather than a right-brain one.

The study findings, which appear in The Lancet, are based
on an analysis of data from a large hospital-based stroke
registry in Germany. Data from more than 20,000 patients were
included in the analysis.

Fifty-six percent of patients had left brain strokes, while
44 percent had right brain strokes. The authors believe a
diagnostic bias may have been involved because age, stroke
severity, and the period from symptom onset to hospital
admission were all significantly linked to left-brain stroke.

In a related editorial, Dr. John N. Fink, from Christchurch
School of Medicine and Health Sciences in New Zealand, comments
that contrary to what might be believed, stroke diagnosis is
not simple.

He adds that it is "up to physicians who assess patients
with stroke to train other physicians, and organize stroke
services to improve our standard of (diagnostic) performance."

SOURCE: The Lancet, July 30, 2005.