What are the treatment options for muscle spasms caused by Central Nervous System (CNS) disorders?

Treatment of Muscle Spasms Caused by CNS Disorders

For muscle spasms caused by CNS disorders, baclofen is the first-line pharmacological treatment, particularly for spasticity from multiple sclerosis and spinal cord injuries, with oral dosing starting low and titrating upward, or intrathecal delivery for refractory cases. 1, 2

First-Line Pharmacological Management

Oral Baclofen

• Baclofen is FDA-approved and indicated specifically for spasticity from multiple sclerosis and spinal cord diseases, providing relief of flexor spasms, concomitant pain, clonus, and muscular rigidity 1
• Start with low doses and titrate gradually to minimize adverse effects (sedation, weakness, dizziness, mental confusion) which typically occur at doses >60 mg/day 2
• Approximately 25-30% of patients with spinal cord injury or MS fail to respond to oral baclofen, and 4-27% discontinue due to intolerable side effects 2
• Baclofen is NOT indicated for skeletal muscle spasm from rheumatic disorders, and efficacy has not been established for stroke, cerebral palsy, or Parkinson's disease 1

Tizanidine as Alternative

• Tizanidine is an alternative oral antispasticity agent that can be titrated up to maximally tolerated doses (up to 36 mg daily in divided doses) 3
• Produces statistically significant reduction in muscle tone (measured by Ashworth scale) at 1-3 hours post-dose in multiple sclerosis patients 3
• Use with caution in elderly patients with renal insufficiency (creatinine clearance <25 mL/min) as clearance is reduced by >50% 3
• Women on oral contraceptives have 50% lower clearance and may require dose adjustment 3

Second-Line: Intrathecal Baclofen

Indications for Intrathecal Delivery

• Reserve intrathecal baclofen (ITB) for patients with intractable spasticity uncontrolled by oral medications or those experiencing intolerable side effects from oral baclofen 2, 4
• ITB delivers drug directly to cerebrospinal fluid at concentrations less than one-hundredth of oral doses, minimizing central side effects like drowsiness and confusion 2
• Level 2 evidence supports short-term effectiveness; Level 3 evidence supports long-term effectiveness for severe spasticity 2

ITB Dosing and Outcomes

• Average 1-year ITB dose for MS-related spasticity is approximately 192 μg/day, substantially lower than doses needed for other spasticity origins 4
• Programmable infusion allows dose variation throughout the day (lower during day for ambulation, higher at night for sleep quality) 2
• Significant reduction in spasm frequency and improved quality of life reported in MS patients 4
• Most complications are surgical rather than pharmacological 4

Condition-Specific Considerations

Multiple Sclerosis

• Baclofen (oral or intrathecal) is the most frequently prescribed drug for MS-related spasticity 2
• ITB shows particular effectiveness with significant spasm frequency reduction and quality of life improvements 4

Spinal Cord Injury

• Both oral baclofen and tizanidine have demonstrated efficacy in controlled trials 1, 3
• ITB is effective for long-term management when oral medications fail 2

Conditions Where Baclofen is NOT Recommended

• Stroke, cerebral palsy, and Parkinson's disease: efficacy not established 1
• Rheumatic disorders causing skeletal muscle spasm 1

Non-Pharmacological Approaches for Functional Neurological Disorders

For Functional Dystonia

• Encourage optimal postural alignment with 24-hour management approach 5
• Promote even weight distribution in sitting, transfers, standing, and walking to normalize movement patterns 5
• Avoid prolonged positioning at end-of-range joint positions 5
• Use muscle relaxation strategies and support affected limbs at rest with pillows or furniture 5
• Avoid splinting as it may increase attention to the area, exacerbate symptoms, increase accessory muscle use, and lead to muscle deconditioning 5

For Functional Tremor

• Entrain tremor to stillness using new rhythms (tapping, hand opening/closing) or music 5
• Control tremor at rest before progressing to activity 5
• Use gross rather than fine movements to reduce concentration demands 5
• Discourage cocontraction or muscle tensing as a suppression method, as this is not a helpful long-term strategy 5

Critical Safety Warnings

Baclofen Withdrawal Precautions

• Withdraw baclofen gradually over several weeks to allow receptor sensitivity to return to normal levels 6
• Abrupt discontinuation can lead to serious complications in patients with pre-existing neuropsychiatric conditions 6

Drug Interactions

• Use baclofen with extreme caution in patients with neuropsychiatric problems or bipolar disorder, as it can worsen depression and interact with antipsychotics 6
• Baclofen alters receptor sensitivity and can cause paradoxical reactions when combined with dopamine antagonists 6

Contraindications for ITB

• Anticoagulant therapy, coagulopathy, local or systemic infection, or anatomical spinal abnormalities preclude intrathecal catheter insertion 2

Treatment Algorithm

1. Confirm CNS etiology: Baclofen is indicated for MS and spinal cord diseases, NOT for stroke, cerebral palsy, Parkinson's, or rheumatic disorders 1

2. Start oral baclofen: Begin with low dose, titrate gradually, monitor for adverse effects at doses >60 mg/day 2

3. Consider tizanidine: If baclofen fails or is not tolerated, trial tizanidine with appropriate dose adjustments for renal function and oral contraceptive use 3

4. Escalate to ITB: If 25-30% of patients who fail oral therapy or experience intolerable side effects, proceed to intrathecal baclofen after appropriate screening 2, 4

5. Integrate non-pharmacological strategies: For functional components, employ movement retraining, postural optimization, and avoid counterproductive interventions like splinting 5