Botulinum toxin type-A treatment in spastic paraparesis: a neurophysiological study.

Abstract

OBJECTIVE:

The aim of this study was to verify the action of Botulinum toxin type-A (BoNT-A) by means of neurophysiological techniques, in patients presenting lower limb spasticity and requiring BoNT-A injections in the calf muscles, due to the poor response to medical antispastic treatment.

SUBJECTS AND METHOD:

Patients presenting paraparesis were enrolled. They underwent clinical evaluation for spasticity according to the Ashworth scale and neurophysiological recordings including: motor evoked potentials (MEPs) to transcranial magnetic stimulation (TMS) of the leg area; compound motor action potential (cMAP) to tibial nerve stimulation, F-wave, and H-reflex before the treatment and 24 h, 2 weeks and 1 month after the injection of BoNT-A. In all patients, gastrocnemius was treated and in some cases soleus or tibialis posterior muscles were also injected.

RESULTS:

In all patients, BoNT-A injections induced a clear clinical improvement as showed by the reduced spasticity values of the Ashworth scale. A significant increment of MEP latency and central conduction time (CCT) duration were observed 2 weeks after the treatment only in the injected muscles.

CONCLUSIONS:

Prolonged MEP latencies and CCT after BoNT-A injections is probably due to a central alteration in responsiveness of spinal motor neurons to descending impulses from the corticospinal tracts. Such changes represent objective parameters heralding clinical efficacy of treatment.

• Authors: F Pauri, L Boffa, E Cassetta, P Pasqualetti, P M Rossini
• Journal: Journal of the neurological sciences (J Neurol Sci) Vol. 181 Issue 1-2 Pg. 89-97 (Dec 01 2000) ISSN: 0022-510X [Print] Netherlands
• PMID: 11099717 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Botulinum Toxins, Type A

Topics

• Adult
• Botulinum Toxins, Type A (administration & dosage, adverse effects)
• Electric Stimulation
• Evoked Potentials, Motor (drug effects, physiology)
• Female
• Functional Laterality (drug effects, physiology)
• H-Reflex (drug effects, physiology)
• Humans
• Magnetics
• Male
• Middle Aged
• Motor Neurons (drug effects, physiology)
• Muscle, Skeletal (drug effects, physiopathology)
• Neural Conduction (drug effects, physiology)
• Paraparesis, Spastic (drug therapy, physiopathology)
• Peripheral Nerves (drug effects, physiopathology)
• Pyramidal Tracts (drug effects, physiopathology)
• Reaction Time (drug effects, physiology)
• Spinal Cord (drug effects, physiopathology)