What are the statistics on spasticity (muscle stiffness) prevalence?

From the Guidelines

Spasticity occurs in approximately 35% of stroke survivors, and if left untreated, it can lead to contracture, activity limitations, and participation restrictions. The prevalence of spasticity varies across different conditions, with about 65-78% of people with multiple sclerosis experiencing spasticity, while 40-60% of stroke survivors develop it [ 1 ]. In cerebral palsy, spasticity occurs in 70-80% of cases, and in spinal cord injuries, it affects 65-78% of patients [ 1 ].

Key Statistics

• Spasticity affects approximately 12 million people worldwide
• 65-78% of people with multiple sclerosis experience spasticity
• 40-60% of stroke survivors develop spasticity
• 70-80% of cerebral palsy cases involve spasticity
• 65-78% of spinal cord injury patients experience spasticity
• 25-43% of traumatic brain injury patients develop spasticity

Treatment and Management

Treatment often involves a combination of physical therapy, oral medications (such as baclofen 10-25mg three to four times daily, tizanidine 2-8mg three times daily, or dantrolene 25-100mg three to four times daily), and interventional approaches like botulinum toxin injections (50-400 units depending on the affected muscles) or intrathecal baclofen therapy [ 1 ]. Early intervention is crucial as untreated spasticity can lead to contractures, pain, and decreased functional independence. The economic burden of spasticity is substantial, with annual costs for treating spasticity in the United States estimated at $4-6 billion [ 1 ].

Prevention and Complications

Spasticity develops due to damage to the upper motor neurons that normally inhibit muscle tone, leading to hyperexcitability of the stretch reflex and increased muscle resistance to passive movement [ 1 ]. If left untreated, spasticity can result in significant pain and functional disturbances, including contractures, skin hygiene problems, and decreased functional independence [ 1 ]. It is essential to treat spasticity if it causes pain or affects mobility, ADLs, or sleep. Indirect management of spasticity involves addressing conditions that may exacerbate spasticity, such as urinary tract infections, fecal impaction, or pressure sores [ 1 ].

From the Research

Spasticity Statistics

• Spasticity occurs in about 50% of patients affected by spinal cord injury and multiple sclerosis 2
• Approximately 25-30% of spinal cord injury and multiple sclerosis patients fail to respond to oral baclofen 3
• The incidence of adverse effects of oral baclofen is reported to range from 10% to 75% 2, 3
• The rate of treatment discontinuation due to intolerable adverse effects of oral baclofen has generally been reported to range from 4% to 27% 3
• More than 80% and more than 65% of patients have improvement in tone and spasms, respectively, with intrathecal baclofen infusion 2, 3
• Level 2 evidence supports the effectiveness of intrathecal baclofen infusion for the short-term reduction of severe spasticity in patients who are unresponsive or cannot tolerate oral baclofen 3
• Level 3 evidence supports the effectiveness of intrathecal baclofen for the long-term reduction of severe spasticity in patients who are unresponsive or cannot tolerate oral baclofen 3
• Spasticity can cause significant pain and limited mobility, leading to decreased quality of life and difficulty maintaining personal care 4
• Spasticity is a common clinical sign in people with neurological diseases, affecting mobility and causing serious complications such as pain, joint limitation, muscular contractions, and bed sores 5

Treatment Outcomes

• Oral medications such as baclofen, tizanidine, and dantrolene are effective in reducing spasticity, but may have adverse effects such as sedation, excessive weakness, and dizziness 4, 2, 6
• Intrathecal baclofen infusion is effective in reducing severe spasticity in patients who are unresponsive or cannot tolerate oral baclofen, with advantages including direct drug administration to the cerebrospinal fluid and minimized central side effects 2, 3
• Focal injection of botulinum toxin, alcohol, or phenol, and surgical resection of selected dorsal roots of the spinal cord are also treatment options for spasticity 4, 6

Epidemiology

• Spasticity is common in many neurological disorders, such as stroke, multiple sclerosis, and spinal cord injury 4, 6, 5
• The impact of spasticity varies from subtle neurological signs to severe spasticity causing pain and contractures 6
• External factors such as constipation, urinary tract infections, or pressure ulcers can worsen existing spasticity 6