Upper limb spasticity is a neurological condition where arm and hand muscles become stiff and overactive. This significantly impacts daily tasks like dressing, eating, or hygiene, making voluntary movements difficult and leading to uncomfortable limb positions.
Understanding Upper Limb Spasticity
Upper limb spasticity involves increased muscle tone. This tone often manifests as stiffness, muscle contractions, and exaggerated reflexes. Affected muscles may remain in abnormal, often flexed, positions.
Individuals with upper limb spasticity might experience involuntary twitches or spasms. These can range from mild tightness to severe contractions that limit range of motion. Unlike general muscle stiffness after exercise, spasticity is velocity-dependent, meaning resistance increases with faster movements.
The condition can lead to specific postures, such as a flexed elbow, pronated forearm, or a clenched fist. Over time, if not managed, these sustained contractions can cause soft tissue changes and fixed deformities known as contractures.
Causes of Upper Limb Spasticity
Upper limb spasticity primarily arises from central nervous system damage. This damage disrupts the normal signaling pathways between the brain and muscles, leading to an imbalance of signals that causes muscles to become overactive.
Several neurological conditions often cause upper limb spasticity. Stroke is a frequent cause, where interrupted blood flow. Traumatic brain injury (TBI) can also result in spasticity.
Other conditions include multiple sclerosis (MS) and cerebral palsy (CP). Spinal cord injuries (SCI) can also lead to spasticity by disrupting communication below the injury site.
Diagnosing and Assessing Upper Limb Spasticity
Medical professionals identify upper limb spasticity through a clinical evaluation, which involves reviewing a patient’s medical history. The examination focuses on observing muscle tone, evaluating reflexes, and assessing the affected limb’s range of motion.
During the physical examination, the doctor will passively move the patient’s arm or hand to feel the resistance in the muscles, noting how this resistance changes with the speed of movement. Healthcare providers may use the Modified Ashworth Scale (MAS) to assign a grade based on the muscle’s resistance to passive movement and track changes.
While scales like the MAS provide a measurable assessment, the diagnosis of upper limb spasticity is primarily clinical. It relies on the healthcare professional’s observations and findings from the physical examination, combined with the patient’s reported symptoms.
Management Approaches for Upper Limb Spasticity
Managing upper limb spasticity requires a comprehensive, individualized approach. Physical therapy is a primary non-pharmacological treatment, focusing on stretching exercises to improve flexibility. Occupational therapy complements this by helping individuals adapt to daily activities, often through the use of adaptive equipment and training to enhance fine motor skills and coordination.
Splinting and bracing are also used to maintain proper limb positioning, provide a sustained stretch to spastic muscles, and prevent the development of contractures. These devices help to improve range of motion and support functional movements.
Pharmacological treatments include oral medications to reduce overall muscle tone. Baclofen and tizanidine are common examples, inhibiting muscle overactivity. While effective, these medications can sometimes cause side effects like drowsiness or dizziness, and their dosages are carefully adjusted.
For more localized spasticity, botulinum toxin injections are a targeted treatment option. These injections are administered directly into specific overactive muscles, temporarily blocking nerve signals that cause muscle contraction. This leads to muscle relaxation, reducing stiffness and spasms, with effects typically lasting several months before repeat injections are needed.
In severe cases where other treatments have not been sufficient, surgical options may be considered. These can include procedures like tendon lengthening or transfers, which modify the affected muscles or tendons. Selective dorsal rhizotomy, another surgical approach, involves cutting specific nerve roots to reduce spasticity.