ORIGINAL ARTICLES   Free access

Europa Medicophysica 1999 March;35(1):27-34

Copyright © 1999 EDIZIONI MINERVA MEDICA

Prognostic value of multimodal evoked potentials in patients in a persistent vegetative state

Monitillo V. ¹, Margari L. ³, Nardulli R. ¹, Franchino G. ¹, Calabrese S. ¹, Multari V. ¹, Colucci F. ¹, Losurdo M. ³, De Iaco M. ³, Megna M. ¹, Megna G. ²

¹ Division of Neurology, “Salvatore Maugeri” Foundation, IRCCS, Rehabilitation Institute of Cassano Murge, Italy; ² Department of Physical Medicine and Rehabilitation, University of Bari, Italy; ³ I Neurological Clinic

BACKGROUND: Numerous stud­ies ­have dem­on­strat­ed the use­ful­ness of neu­ro­phys­io­log­i­cal inves­ti­ga­tions ­with somat­o­sen­so­ri­al, brain­steim audi­to­ry and vis­u­al ­evoked poten­tials (SEPs, BAEPs, VEPs) for com­plet­ing the clin­i­cal exam­ina­tion and eval­u­a­tion of ­coma ­patients. Recently, new non­in­va­sive tech­niques for trans­cra­ni­al stim­u­la­tion of the ­motor cor­tex ­have ­been util­ised ­with electri­cal or mag­net­ic stim­u­la­tion, ­which ­allow the record­ing of ­motor ­evoked poten­tials (MEPs) in the cor­re­spond­ing mus­cles of the stim­u­lat­ed ­area. This pro­vides infor­ma­tion on the integ­rity of the cor­ti­co-spi­nal ­motor path­ways. Few neu­ro­phys­io­log­i­cal stud­ies ­have ­been car­ried out in ­patients in a per­sis­tent veg­e­ta­tive ­state (PVS).
METHODS: A per­spec­tive neu­ro­phys­io­log­i­cal ­study was per­formed in 8 ­patients in a per­sis­tent veg­e­ta­tive ­state (PVS). The clin­i­cal pat­tern was eval­u­at­ed ­using the Glasgow Outcome Scale at 4, 7 and 10 ­months ­after the path­o­log­i­cal ­event. Neurophysiological inves­ti­ga­tions includ­ing brain­stem audi­to­ry ­evoked poten­tials (BAEPs), ­median ­nerve som­a­tos­en­so­ry ­evoked poten­tials (MN-SEPs) and ­motor ­evoked poten­tials (MEPs) ­were car­ried out at 4 ­months, ­with fol­low-up at 7 ­months.
RESULTS: At the ­first assess­ment and fol­low-up, BAEPs ­were nor­mal in all but one of the ­patients (mono­lat­er­al ­absence of all ­waves due to a periph­er­al ­lesion). SEPs ­were nor­mal in ­only 1 ­patient in ­whom the clin­i­cal sit­u­a­tion ­evolved to ­severe dis­abil­ity; in the remain­ing ­patients SEPs ­revealed dif­fer­ent ­degrees of alter­a­tion. At fol­low-up, SEP record­ings had ­improved in 3 ­patients: 2 ­evolved to ­severe dis­abil­ity and 1 to mod­er­ate dis­abil­ity.
CONCLUSIONS: Our ­study sug­gests ­that SEPs ­could ­have a prog­nos­tic val­ue for the clin­i­cal evo­lu­tion of ­patients in a PVS.