Obturator nerve block with aqueous phenol reduces hip adductor spasticity

Abstract

Spasticity is a cardinal symptom of the upper motor neuron syndrome. It affects the different individuals differently. Hip adductor spasticity can be very painful and result in postural abnormalities that interfere with walking, transferring and hygiene. Phenol block of the obturator nerve results in neurolysis reducing the hip adductor spasticity. Patients with known spasticity in the lower limbs who had been assessed suitable for phenol nerve block had Modified Ashworth Scale (MAS) and intercondylar distances recorded before the phenol nerve block, the at 6 weeks and 6 month's post phenol nerve block. Non-parametric Friedman test of differences among repeated measures was conducted from data at 0, 6 and 24 weeks. Fifty-two obturator nerves were blocked using 5% phenol. The procedure was bilateral in 38 patients and unilateral in 14 patients. There were 34 females and 18 males. Minimum age was 18 years and maximum age was 78 years with a mean age of 50.6 years. Majority of patients (28.8%) had a diagnosis of multiple sclerosis. There was statistically significant difference between the pre-injections MAS and intercondylar distance at 6 weeks and 6 months. Spasticity of the lower limb, especially adductor muscle spasm, is a major source of long-standing disability and pain in neurological patients. It is a cost-effective procedure that leads to improved personal hygiene. It is operator dependent and needs skills and training to inject phenol without complications.