Neurolytic blockade of the obturator nerve for intractable spasticity of adductor thigh muscles.

Neurolytic blockade is one of the therapeutic possibilities to treat spasticity of various muscles. In patients with spasticity of the adductor thigh muscles, a percutaneous approach to the obturator nerve is often difficult. We describe a new approach to the obturator nerve and we examine its feasibility. The second objective was to assess the efficacy of obturator neurolysis for the management of adductor thigh muscle pain and spasticity associated with hemiplegia or paraplegia. Nerve blocks were performed via a combined approach using fluoroscopy and nerve stimulation to identify the obturator nerve. Neurolysis was performed by injection of 65% ethanol. We performed 27 blocks in 23 patients. Technical evaluation was achieved in terms of number of attempted needle insertions, time to accurate location of the nerve and success rate. The efficacy of the block was assessed using four scores: degree of alleviation of muscle spasm and triple flexion of the lower limb, improvement of gait and facilitation of hygienic care. Success rate of the technique was 100% with a time to accurate nerve location of 130+/-35 s. Compared with scores measured immediately before the block, all studied parameters were significantly improved. Efficiency was significant on adductor muscle spasticity (p<0.001 at 1 day and p<0.01 at 60 and 120 months). Triple flexion was also significantly improved (p<0.05 from 1 to 120 days), as well as gait (p<0.02) and hygiene (p<0.01) scores. No complications occurred. The combined approach of the obturator nerve represents a new technique which proved to be accurate, fast, simple, highly successful and reproducible. Obturator neurolysis was confirmed as an efficient and cost-effective technique to reduce adductor muscle spasm and related pain and to improve gait and hygienic care in patients with neurological sequelae of stroke, head trauma or any lesion of the motor neurone. Copyright 2002 European Federation of Chapters of the International Association for the Study of Pain.