Fig 1.
Vestibular-evoked myogenic potential triggered by galvanic vestibular stimulation procedure.
The standing position of the patient (barefoot on a hard flat surface with eyes closed, feet close together and body leaning forward in order to cause the gastrocnemius muscle contraction); the equipment used for stimulus generation (a); the electrode positions for GVS (b); the electrode position for electromyography on the gastrocnemius muscle (c); the equipment for signal processing (d); and the laptop (e) connected to (a) and (d).
Fig 2.
Normal, delayed, and abnormal response patterns in vestibular-evoked myogenic potential triggered by galvanic vestibular stimulation (galvanic-VEMP).
(A) Normal electromyographic (EMG) response recorded from the gastrocnemius muscle. The black line indicates the trace with the cathode on the right and the anode on the left, whereas the gray line indicates the opposite stimulation polarity. SL (~50 ms) and ML (~100 ms). (B) Delayed EMG responses. SL ~80 ms and ML ~150 ms. (C) Absent EMG response, no SL and no ML.
Table 1.
Galvanic-VEMP variables (SL and ML): Comparison between groups.
Table 2.
Intrarater (test-retest) and interrater agreement and reliability measures of galvanic-VEMP variables (SL and ML) in the total sample (n = 96).
Table 3.
Intrarater (test-retest) and interrater agreement and reliability measures of galvanic-VEMP variables (SL and ML) in HTLV-1 negative controls (n = 45).
Table 4.
Intrarater (test-retest) and interrater agreement and reliability measures of galvanic-VEMP variables (SL and ML) in HTLV-1 asymptomatic carriers (n = 27).
Table 5.
Intrarater (test-retest) and interrater agreement and reliability measures of galvanic-VEMP variables (SL and ML) in individuals with HAM (n = 24).