Is baclofen effective in treating spasm in paraplegia?

Baclofen for Spasticity in Paraplegia

Baclofen is useful for the treatment of spasticity in paraplegia, particularly for relieving flexor spasms, concomitant pain, clonus, and muscular rigidity in patients with spinal cord injuries. 1

Mechanism and Effectiveness

• Baclofen is a GABAB agonist that effectively reduces spasticity of spinal origin, which is common in spinal cord injury patients 2
• In clinical studies, oral baclofen improved spasticity in 70-87% of patients and reduced spasms in 75-96% of patients with spinal spasticity 2
• Baclofen is particularly effective for the relief of flexor spasms, pain, clonus, and muscular rigidity in patients with spinal cord injuries 1

Administration Options

Oral Baclofen

• Typical dosing range for oral baclofen is 30-80 mg/day, divided into 3-4 doses 3
• Oral baclofen can be effective in many patients with spasticity regardless of severity, and is comparable with other antispasmodic agents 4
• Common side effects include sedation, excessive weakness, vertigo, and psychological disturbances, affecting between 25-75% of patients 2
• Withdrawal symptoms can include seizures, psychic symptoms, and hyperthermia, which improve after reintroduction of baclofen 2

Intrathecal Baclofen

• Intrathecal baclofen is indicated for patients with spasticity of spinal origin who are unresponsive to maximum doses of oral baclofen 2
• Intrathecal administration allows for direct delivery to the cerebrospinal fluid, bypassing the blood-brain barrier and optimizing efficacy while minimizing side effects 4
• Studies show >80% of patients have improvement in muscle tone and >65% have improvement in spasms with intrathecal baclofen 2
• In a randomized double-blind crossover study, muscle tone decreased significantly in all 20 patients with spinal spasticity (mean Ashworth score from 4.0 to 1.2) 5

Treatment Algorithm for Spasticity in Paraplegia

1. First-line approaches:

   • Antispastic positioning, range of motion exercises, stretching, splinting, and serial casting 6, 3

2. Pharmacological options:

   • Oral baclofen starting at low doses (5-10 mg/day) and titrating slowly to minimize side effects 3
   • Alternative oral agents include tizanidine and dantrolene for generalized spasticity 6
   • Botulinum toxin for focal spasticity 6

3. Advanced options for severe or refractory cases:

   • Intrathecal baclofen for severe spastic hypertonia that does not respond to other interventions 6
   • Neurosurgical procedures such as selective dorsal rhizotomy or dorsal root entry zone lesion as last resort options 6

Important Considerations and Precautions

• Baclofen should not be abruptly discontinued due to risk of withdrawal symptoms 2
• Caution is advised in patients with renal disease as they may be at higher risk for toxicity 2
• Intrathecal baclofen risks include symptoms related to overdose or withdrawal; the latter can be severe and potentially fatal but responds to rapid treatment 2
• Regular follow-up is essential to monitor efficacy and adjust dosing as needed 7
• In addition to reducing spasticity, baclofen may improve quality of life by reducing pain related to contractures 7