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Use of electrophysiologic tests to measure disease progression in ALS therapeutic trials
Author(s) -
Kelly John J.,
Thibodeau Linda,
Andres Patricia L.,
Finison Lorenz J.
Publication year - 1990
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.880130602
Subject(s) - isometric exercise , medicine , physical medicine and rehabilitation , spasticity , physical therapy , weakness , correlation , clinical trial , surgery , mathematics , geometry
A battery of electrophysiologic tests was developed to assess the relative degree of lower and upper motor neuron (spasticity) deficit in a group of ALS patients enrolled in a therapeutic trial. Test results were correlated with strength in the tibialis anterior muscle as determined by measurement of maximum voluntary isometric contraction (MVIC), using strain gauge tensiometers, and were also correlated with a clinical spasticity rating scale. Patients were tested every 6 to 8 weeks over more than 1 year. Compound muscle action potential amplitude (CMAPa) from tibialis anterior correlated best with MVIC and also showed a strong linear correlation with time, as did MVIC. Other tests correlated poorly with MVIC on the average, although individual patients did show high correlations. In those patients where correlation between CMAPa and MVIC was low, MVIC did not show a high linear correlation with time and was also highly variable. This study suggests that the addition of CMAPa should be considered in ALS therapeutic trials if MVIC is not available. In addition, CMAPa can be useful in study samples where MVIC deterioration is not linear over time or is highly variable.