Phenol is believed to reduce spasticity via direct neurolysis causing damage to the alpha motor fibers of the nerve(s) affected. Phenol neurolysis is not specific for the motor fibers and therefore can cause secondary sensory nerve damage and complications such as painful neuropathy (On et al. 1999).
Phenol blocks have been used to successfully treat spasticity in a number of conditions including stroke, SCI, multiple sclerosis and cerebral palsy (Uchikawa et al. 2009; Albert et al. 2002; On et al. 1999; Kirazli et al. 1998; Yadav et al. 1994; Wassef et al. 1993). Only two studies were identified that met our criteria for the treatment of spasticity in spinal cord injury.
Uchikawa et al. (2009) examined the use of phenol blocks for the management of painful shoulder girdle spasticity in persons with cervical level spinal cord injury. In an open label, case series, seven individuals with cervical level spinal cord injury with shoulder pain and limited range of motion were treated with phenol motor point blocks to the subscapularis muscle. They observed significant improvements in passive ROM in flexion (23.71), abduction (19.41)and external rotation (16.81; P<0.05) and decreases in the visual analog scale for shoulder pain which was reduced from 6.0 to 3.4 (P<0.05). They did not however observe any significant change in the modified Ashworth scale for shoulder spasticity. The eating Functional Independence Measure item score improved significantly (P<0.05).
In another case series, Yasar et al. (2010) also examined the efficacy of a phenol block on the obturator nerve for the reduction of hip adductor spasticity. The authors reported a statistically significant decrease in spasticity post-treatment.
Alcohol neurolysis works in a manner similar to phenol. It has been studied in the management of spasticity in hemiplegia and in focal dystonias, all with some success. Our literature search failed to reveal any studies in managing spasticity in SCI.
Based on 1 case series study, there is level 4 evidence that phenol neurolysis reduces hip adductor spasticity in individuals with paraplegia and tetraplegia in SCI.
There is no literature to support the use of focal neurolysis with alcohol in the management of spasticity in spinal cord injury.
Phenol block may improve pain, range of motion and function related to shoulder spasticity in individuals with tetraplegia.
Phenol block may reduce hip adductor spasticity in individuals with paraplegia and tetraplegia.