Long-term prognosis of poststroke aphasia studied with positron emission tomography.

OBJECTIVE

To evaluate positron emission tomography with the use of fludeoxyglucose F 18 as a predictor of the long-term outcome of poststroke aphasia.

BACKGROUND

Positron emission tomography shows functional deficits after stroke even in morphologically intact brain regions. The regional metabolic impairment can be related to the clinical deficit. Little is known about whether regional hypometabolism early after stroke predicts the long-term prognosis of stroke sequelae.

PATIENTS AND METHODS

Twenty-two patients with language disturbance caused by a single lesion in the territory of the left middle cerebral artery were studied with fludeoxyglucose positron emission tomography and with a neuropsychological test battery that included a test of receptive language (Token Test) and a test of word fluency (/f/, /a/, /s/ test). The neuropsychological test was readministered about 2 years after the initial test.

RESULTS

Regional cerebral metabolic rates of glucose measured early after stroke showed a highly significant correlation with the results of the 2-year follow-up test. The receptive language disorder best correlated with cerebral metabolic rates of glucose in the left superior temporal cortex, and word fluency correlated with cerebral metabolic rates of glucose in the left prefrontal cortex.

CONCLUSION

Cerebral metabolic rates of glucose in speech-relevant brain regions measured early after stroke are a predictor of the eventual outcome of aphasia.