[Treatment of spasticity with intrathecal baclofen]

Severe spasticity, according to Lance's definition, is a manifestation of superior motoneurone injury syndrome which is characterized by increased stretching tonic reflexes, osteotendinous hyperreflexia, and release of propioceptive reflexes. Baclofen (a beta-4 chlorophenyl derived from gamma-amino-butyric acid) was firstly administered by intradural route in humans by Penn and Kroin in 1985 for the treatment of severe spasticity of muscular and central origin.

We report the results obtained in eleven patients with severe spastic picture, six of medullar origin and five of central origin who were treated with intradural administration of baclofen using an implanted programmable continuous perfusion system (Synchromed 8611H). The age of patients ranged from 12 up to 58 years. Six were males and five females. The duration of the treatment ranged from a maximal period of 36 months to a minimal period of 12 months. The initial dose of baclofen varied from 50 micrograms/day to 144 micrograms/day.

The better results were obtained in patients with spasticity of medullar origin. The most marked beneficial effects were the reduction of spasms elicited, or not, by external stimuli. In all cases the doses of baclofen had to be progressively increased, leading to a mean final dose of 235.6 micrograms/day, with a maximal dose of 480 micrograms/day and a minimal dose of 144 micrograms/day.

Baclofen administered by intradural route is more effective than administered by orally and the required doses were lower. Intradural administration was effective even though the oral route was unsuccessful.