Site and size of lesion predict post-stroke spasticity: A retrospective magnetic resonance imaging study

Clinical parameters for prediction of post-stroke spasticity are well established. This report introduces 2 brain magnetic resonance imaging (MRI) parameters (infarct volume and topographic distribution) as post-stroke spasticity predictors.

Topographic and volumetric data from brain MRI for 98 patients with ischaemic stroke with spasticity, prevalent within the first 5 days after stroke and 6 months after stroke, were retrospectively correlated using Chris Rorden's MRIcron software.

Lesions within the supply territory of the middle cerebral artery involving the pyramidal tract were more frequently associated with spasticity than without spasticity (30.8% vs 5.1%). Middle cerebral artery lesions not affecting the pyramidal tract were found more often in patients without spasticity (49.2% vs 10.3%). Spasticity showed a significantly higher association with middle cerebral artery+pyramidal tract/internal capsule lesions than did "no spasticity" (97.5% vs 18.7%, p < 0.01), and lesion volumes were significantly larger in patients with spasticity than in those without spasticity (p < 0.01).

Large stroke volumes might predict post-stroke spasticity if the lesion is > 3 cm3 in size and if the lesion is located within the middle cerebral artery territory with involvement of the pyramidal tract and/or internal capsule. Lesion size ≤ 2 cm3 outside the middle cerebral artery territory is associated with lower risk of post-stroke spasticity.