Inter-Rater Reliability of a Spasticity Diagnosis Algorithm

Spasticity is defined as a velocity-dependent increase in stretch reflex with muscle overactivity, and is associated with involuntary limb movements or spasms which can often be painful. Active function (such as walking, driving, writing, or sexual activity) can be adversely affected by spasticity. For patients with significant disability requiring a caregiver, passive function (such as facilitation of bathing, dressing, and undergarment change) can also become very difficult, especially when spasticity is left untreated. Finally, persistent involuntary motion or spasms may negatively impact an individual's mood or self image, making social situations more difficult and sometimes overwhelming.

Spasticity is especially undertreated in vulnerable populations; population surveys in individuals with intellectual disability and nursing home residents have shown that less than 20% of affected individuals are treated. There are severe negative consequences of leaving spasticity untreated, like muscle shortening and tendon and soft tissue contractures. Once developed, contractures are very difficult to treat and can hinder personal hygiene and dressing, and well as the ability to sit or lie properly. Bad hygiene and immobility can lead, in turn, to urinary tract infections, pressure ulcers and skin breakdown. Furthermore, spasticity can stunt muscle growth and cause abnormal bone growth and formation, especially in children.

Spasticity is diagnosed based upon a physician's clinical impression; there is currently no biomarker to facilitate an objective diagnosis. The two instruments most commonly used to document severity are the Modified Ashworth Scale and Range of Motion Assessment. Both assessments are based upon a clinician's assessment of muscle tone, but there is no widely-accepted protocol to determine the presence of spasticity. We therefore hypothesize one reason spasticity is widely undertreated is the challenge faced by physicians when attempting to make a diagnosis. In the absence of a biomarker, a more standardized method of clinical diagnosis is necessary, both for future research and for advocacy efforts. The treatment of spasticity could increase quality of life by allowing an individual to participate more independently in activities of daily living, and by making assistance easier for caregivers.