Poststroke Hypertonicity: Upper Limb Assessment and Treatment

Abstract

Hypertonicity is common in patients with upper limb dysfunction following hemiplegic stroke and is associated with greater impairment, worse function, and lower health-related quality of life. In addition to increased rest activity, abnormal patterns of muscle activation, such as spastic co-contraction, may contribute to disability. In the upper limb, flexor muscles are more commonly involved distally, and at the shoulder, spasticity of adductors, flexors, and internal rotators is most often observed. Prior to interventions, a history regarding prior interventions, comorbid diagnoses, and limitations imposed by abnormal tone should be elicited. Commonly used scales to assess hypertonicity include the Modified Ashworth, the Modified Tardieu, the Spasm Frequency, the Disability Assessment, the Fugl-Meyer, and the Motor Assessment Scales. Treatment interventions for upper limb hypertonicity include stretching, splinting, strengthening of antagonist muscles, oral medications, and focal injections (phenol or botulinum toxins). Intrathecal baclofen may also impact upper limb tone. For focal injections, correct identification of muscles contributing to problematic tone is evaluated by eliciting resistance to movement at rest and observation of patterns of tightness as the limb is used functionally. The botulinum toxins have been shown to decrease tone in stroke survivors and improve active and passive functioning. Because secondary changes such as contractures and weakness may occur with prolonged hypertonicity, therapy to improve range of motion, strengthen weakened muscles, and incorporate use of the limb should be considered following focal injections, oral medications, or intrathecal pump placement.