Using Voice Onset Time (VOT) in association with oral and laryngeal diadochokinesia in evaluation of the dysarthria in Amyotrophic lateral sclerosis

Abstract

Amyotrophic lateral sclerosis is a progressive degenerative disease that involves the motor neurons (upper and lower motor neurons). The presenting clinical symptoms are associated with involved areas and include speech disorders, swallowing disorders and respiratory problems. The diadochokinesia (DDK) is used to evaluate speech disorders presenting on ALS. The Voice Onset Time (VOT) analysis in association with diadochokinesia may contribute to improve analysis of speech in subjects with ALS. 10 subjects with ALS were studied (GE) and 13 subjects without neurological problems were the control group (GC). The number of ALS´ subjects in this study represents a considerable corpus as the ALS disease has a fast progression and the subjects were in an advanced state of the disease. The DDK and VOT were measured. The statistical analysis of DDK data showed differences between groups to Average Diadochokinesia Period (AVP), Average Diadochokinesia Rate (AVR), Standard Deviation of Period (SDP) and Perturbation of Diadochokinesia Period (JITT) parameters. AVP and AVR showed differences in all tasks. JITT and SDP indicated differences to /ta/ and /ka/ tasks. The VOT analysis allows a qualitative characterization of the subjects´ speech production in DDK and showed that the subjects (with bulbar symptoms) did not produce the sound production expected what turns the singular use of DDK analyzes insufficient in this cases. Associate VOT and DDK guarantees complete and qualitative analyses of speech production in ALS disease, which can present immobility of facial movements.