Prognostic value of subacute crossed cerebellar diaschisis: single-photon emission CT study in patients with middle cerebral artery territory infarct

Abstract

Background and purpose: Although chronic-stage crossed cerebellar diaschisis (CCD) is reported to be associated with the neurologic state or clinical improvement after infarct, the prognostic value of early-stage CCD remains controversial. Our aim was to determine whether measurements of CCD in the acute and subacute stages obtained at single-photon emission CT (SPECT) facilitate the prediction of stroke outcome.

Methods: The pattern of cerebral blood flow changes after the occurrence of acute middle cerebral artery ischemia with severe cortical symptoms was examined by using technetium 99m-hexamethylpropyleneamine oxime ((99m)Tc-HMPAO) SPECT. Fifteen patients (mean age, 73 years +/- 8 [SD]) with unilateral ischemia were examined in the early subacute stage (10 days +/- 5). In 11 patients, SPECT was performed in both the acute (16 hours +/- 10) and subacute stages. From the total counts obtained from each cerebellar hemisphere, the asymmetry index (AI) was calculated as follows: [(value in unaffected hemisphere--value in affected hemisphere)/value in unaffected hemisphere] x 100. Clinical outcome (at 60 days) was assessed by means of the Scandinavian Stroke Scale (SSS) and Barthel Index (BI).

Results: AIs in the acute stage and clinical outcome (ie, SSS and BI scores) showed no significant correlation, but the severity of AI in the early subacute stage correlated significantly with both the final SSS (r = -0.69; P <.01) and BI scores (r = -0.82; P <.01).

Conclusion: Cerebellar hypoperfusion detected at (99m)Tc-HMPAO SPECT in the early subacute stage in patients with supratentorial infarct indicates a worse clinical outcome.

Fig 1.

ROIs on a SPECT image of the cerebellum.

Fig 2.

SPECT images obtained in patient 1 show severe cerebellar hypoperfusion (arrows) in both the acute (top row) and subacute (middle row) stages. This patient had SSS scores of 13 at admission and 38 at 60 days after onset. MR images (bottom row) obtained at 32 days show a large infarct in the left hemisphere.

Fig 3.

SPECT images obtained in patient 13 show cerebellar hypoperfusion (arrows) in both the acute (top row) and subacute (middle row) stages. This patient had SSS scores of 22 at admission and 55 at 60 days after onset. MR images (bottom row) obtained at 58 days show an infarct in the right basal ganglia and frontal lobe.

Fig 4.

Relationships between the AI in the subacute stage and neurologic state. No significant (N.S.) correlations between the AI in the subacute stage and SSS score at admission were found (top left). AI in the subacute stage was significantly associated with the final SSS score at 60 days (top right), the final BI score at 60 days (bottom left), and the RI (bottom right), as the results of the nonparametric Spearman rank test indicate.