Extent of pontine pyramidal tract Wallerian degeneration and outcome after supratentorial hemorrhagic stroke.

BACKGROUND AND PURPOSE: Pyramidal tract Wallerian degeneration has been detected on magnetic resonance imaging (MRI) as T2-weighted high-intensity areas. We analyzed the relation between the extent of brain stem Wallerian degeneration and activities of daily living (ADL) after supratentorial hemorrhagic stroke.

METHODS

Twenty-six patients with supratentorial hemorrhage were examined on the coronal T2-weighted image of the pons 3 months or later after stroke, and the percentage of Wallerian degeneration in the pons was calculated. The patients were divided into three groups. In group A (n = 6), MR films were taken 3 to 6 months from the onset, and the ADL assessment was done within 2 months from the MRI. In group B (n = 11), MR films were taken 3 to 6 months from the onset, and the ADL assessment was done within 10 months from the MRI (mean, 15.5 months from the onset). In group C (n = 9), MR films were taken after 10 to 17 months (mean, 12.0 months) from the ictus, and the ADL assessment was done simultaneously. Barthel Index score was used for quantitative ADL assessment.

RESULTS

All patients showed various degrees of pontine pyramidal tract Wallerian degeneration associated with capsular involvement by the hematoma. In group A, the percentage of degeneration did not correlate with the Barthel Index score (r = .2101, P = .6895). An inverse relation between percentage of degeneration and Barthel Index score was seen in groups B (r = .7354, P = .0099) and C (r = .888, P = .0014). In groups B and C, Wallerian degeneration was higher in patients with Barthel scores less than 60 (P = .005).

CONCLUSIONS

The extent of pontine Wallerian degeneration on MRI 3 months or later after the stroke correlated with the patient's Barthel Index score 1 year after the stroke.