How is spasticity treated in amyotrophic lateral sclerosis (ALS)?

Updated: Jul 27, 2021
  • Author: Divakara Kedlaya, MBBS; Chief Editor: Ryan O Stephenson, DO  more...
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Spasticity occurs in ALS patients from loss of inhibition from upper motor neurons. The development of spasticity in people with ALS adds significantly to their functional decline and to the reduction in quality of life for the individual. Nonpharmacological treatments should be tried first before adding medications; these include regular stretching and other types of exercises. A Cochrane review found only one randomized controlled trial in the world literature that looked at the treatment of spasticity in motor neuron disease, which implies there is a huge gap in our knowledge of this area. [26]

Baclofen acts as a gamma-amino butyric acid (GABA) agonist and is the drug of choice for the treatment of spasticity in patients with ALS. Alpha2-adrenergic agonists, such as tizanidine and clonidine, also may be effective, but hypotension is a potential adverse effect that may limit their use.

Dantrolene interferes with excitation-contraction coupling and usually is used as an adjunct agent. Dantrolene does have potential for hepatotoxicity; therefore, monitor liver function tests closely in patients treated with this medication. Benzodiazepines facilitate GABA in the central nervous system (CNS) and are effective in the treatment of spasticity.

Use these medications with extreme caution in patients with ALS because of their adverse effect of respiratory depression. Patients may already be compromised from a respiratory standpoint, and this class of medications may worsen residual respiratory function. Carefully monitor the use of antispasticity agents, because they can cause sedation, dizziness, increased weakness, or other adverse effects that may be potentially harmful to the patient.

In severe cases, an intrathecal baclofen pump can be considered. In a case series by McClelland et al, 8 patients with ALS with severe spasticity and pain were treated with intrathecal baclofen pump. Following intrathecal baclofen pump placement, the average reduction of pain was 54%. Six patients (75%) experienced pain score reduction, 3 of whom had complete pain relief. [27]

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