Article

Sporadic cases of recovery from persistent vegetative state (PVS) after
administration of intrathecal baclofen (ITB) have been reported without giving
any possible explanation for its paradoxical effect. We summarize our recent
findings on 5 patients with PVS treated with ITB and make some speculations on
the mechanisms responsible for the observed clinical improvement. The patients
developed spasticity and were judged eligible for ITB therapy. Two weeks after
pump implantation, patients began to show a clinical improvement that, at the end
of the 6 months' follow-up, was stable in all but 1 patient, ranging from a mere
increased alertness to a full recovery of consciousness, as revealed by changes
of the Coma Recovery Scale-Revised (CRS-R) score. Our findings suggest that ITB
might favor a variable degree of clinical improvement. A proposal for a
pharmacodynamic explanation of this effect has not been formally put forward. We
hypothesize 2 possible mechanisms: first, a modulation confined to spinal cord
segmental activities and to neuronal centripetal outputs reaching the cortex; and
second, a modulation of sleep-wake cycles that, although present, may be
dysregulated and interfere with alertness and awareness. Although our research is
confined to a few subjects, it provides follow-up information by means of the
CRS-R that is a validated standardized neurobehavioral instrument expressly
designed for use in patients with PVS. Our observations indicate that further
systematic investigation of the mechanisms and the putative clinical applications
of ITB should be undertaken.

Langue : ANGLAIS