The response to epidural steroid injections in chronic dorsal root pain

Thirty-seven patients with long-standing post-herpetic neuralgia and 27 with post-traumatic neuralgia (PTN) were treated with three epidural injections each of methylprednisolone acetate (Depo Medrol) given at weekly intervals. Differential subarachnoid or epidural block was done in all patients and placebo responders were excluded from the study. Mean age, duration of symptoms, and pain intensity measured by visual analogue scale were similar in both groups. Visual analogue scale ratings were reduced one month after treatments from both groups. Visual analogue scale ratings were reduced one month after treatments from pretreatment values of 84.4 and 78.7 to 9.6 and 15.2 in the post-herpetic and post-traumatic groups respectively, and were further reduced to 4.6 and 11.6 respectively after one year when 89 per cent of patients in the post-herpetic group and 59 per cent of patients in the post-traumatic group were completely pain free. Side effects were minor in all cases. It is suggested that this is the treatment of choice in post-herpetic and post-traumatic neuralgia where steroid administration is not contraindicated.