Biomedical subjects

A A Rodriquez

Publications and source records attributed to A A Rodriquez.

41 records · Page 3Linked to original sources

PubMedDate not supplied

Electromyographic assessment of spasmodic dysphonia patients prior to botulinum toxin injection.

Electromyographic (EMG) evidence of inappropriate muscle activity (IMA) in the cricothyroid (CT) and vocalis (V) (thyroarytenoid) muscles was correlated with clinical voice measures in 32 patients with spasmodic dysphonia (SD). Subjective voice rating and quantified fluency and laryngeal diadochokinesis measures were obtained prior to botulinum toxin (Botox) injection into the V muscles. Pre-Botox EMG was performed using a monopolar needle electrode. Each muscle was sequentially examined at rest, during vocal click, scale, sustained "E" at different pitches, and repeated "E" voicings for brief periods. A three point EMG severity scale was used to grade the amount of IMA seen in each muscle. EMG evaluation showed no evidence of lower motor neuron involvement but did reveal IMA in 81.3% of the subjects. There were no significant correlations for the patients between different EMG-based IMA severity scales and the measures of voice quality and sound production. EMG did discriminate between predominantly adductor and abductor SD pattern types, but could not correctly differentiate a mixed SD group. Those patients with adductor SD displayed IMA in the V and CT muscles, while those with abductor SD displayed more IMA in the CT than the V muscles. Sequential EMG assessment of CT and V IMA in SD did not predict clinical severity or outcome following Botox injection into the V muscles.

Adult↗

PubMedDate not supplied

Close-proximity concentric and modified single fiber electromyographic recordings using revised techniques with a paired wire electrode.

Using a combined concentric (CN) and modified single fiber (MSF) electromyographic needle electrode with both recording surfaces at the tip approximately 25 microns apart, 24 motor unit potentials (MUPs) were recorded from one extensor digitorum communis muscle, triggering from either the CN or MSF channel in equal numbers and averaging both CN and MSF recordings. Filter settings were 20-10,000 Hz. Correlations of MUP amplitude, phases, turns, negative turns (NTs), and main spike duration, but not rise time or duration, between the CN and MSF recordings were statistically significant (P < 0.05). Mean +/- SD numbers of estimated single fiber potentials (ESFPs) and NTs for the MSF recordings were 1.17 +/- 0.38 and 1.54 +/- 0.72. Correlations between numbers of ESFPs and turns, NTs and phases, NTs and turns, and NT and main spike duration for the MSF and CN MUP recordings, respectively, were statistically significant (P < 0.05). The study findings using these techniques continue to support evidence that one or a few muscle fibers contribute to the main spike component of the MUP.

Action Potentials↗

PubMedDate not supplied

Median nerve electrophysiologic parameters and psychomotor performance in carpal tunnel syndrome.

Psychomotor performance (PMP) involving a repeated, rapid pinch and release task was correlated with median nerve electrophysiologic parameters for control subjects (16 hands) and subjects with carpal tunnel syndrome (CTS) (14 hands). The psychomotor task was used because of its functional resemblance to many work related activities. A strain gauge dynamometer was repeatedly pinched to a predetermined force level using the index finger and thumb and then released as rapidly as possible, while measuring the actual isometric force exerted. Discrete visual and auditory feedback was provided. Median and ulnar nerve motor latencies and amplitudes, as well as median antidromic sensory latencies and amplitudes, and transcarpal latencies and amplitudes were obtained. CTS subjects had longer median motor and sensory latencies and were weaker than controls, however median motor and sensory amplitudes were not statistically different. A strong relationship was observed between electrophysiologic variables and PMP, which could not be accounted for by age differences alone. It is unclear whether the measured differences in PMP are related to sensory or motor deficits.

Adult↗

PubMedDate not supplied

A comparison of close proximity concentric and modified single fiber electromyographic recordings from extensor digitorum communis.

Using a combined concentric (CN) and modified single fiber (MSF) electromyography (EMG) needle electrode with both recording surfaces at the tip approximately 25 microns apart, 30 motor unit action potentials (MUAP) were recorded from one extensor digitorum communis (EDC) muscle, triggering from the CN and averaging both the CN and MSF recordings. Correlations of MUAP amplitude (r = 0.767), number of turns (r = 0.839), and number of negative-going-positive-going turn (NT) (r = 0.737) between the CN and MSF recordings were statistically significant (p < 0.001). For NTs common to both recordings, correlations of rise time (r = 0.866), amplitude (r = 0.816), and interpeak interval (IPI) (r = 0.999) were statistically significant (p < 0.001). Mean +/- SD single fiber potentials (SFP), approximate SFP with rise times less than 500 microseconds, and NTs for the MSF recordings and NTs for the CN recordings were 0.73 +/- 0.69, 1.20 +/- 0.48, 1.83 +/- 0.87, and 1.93 +/- 0.78, respectively. This study supports evidence that one or a few SFP contribute to the spike component of the MUAP.

Action Potentials↗

PubMedDate not supplied

Subjective recovery time after exhausting muscular activity in postpolio and control subjects.

The purpose of this study was to determine whether the time to subjectively fully recover after the performance of exhausting muscular exercise was greater in unstable postpolio as compared with stable postpolio or control subjects. Twenty-five unstable (those complaining of declining muscle strength) postpolio, 16 stable (those denying declining muscle strength) postpolio, and 25 control subjects performed an isometric contraction of the knee extensor (quadriceps femoris) musculature at 40% of maximal torque until they were no longer able to do so. Five-second maximal effort contractions were made every 30 s through 2 min after the time of failure was reached and then at 1-min intervals through 10 min after failure was reached. Subjects reported the duration of time required to subjectively fully recover from this activity. Choices of "less than 1 day," "1 day," "2 days," etc., up to "greater than 2 wk" were given to the subjects for their response. Analysis was by nonparametric ANOVA and appropriate post hoc comparison procedures. Unstable postpolio subjects reported a greater recovery time than either the stable postpolio or control subjects (mean +/- SD of 2.6 +/- 3.0 days, 0.6 +/- 1.0 days, and 0.7 +/- 1.1 days, respectively, P < 0.05). Thus, the reported recovery time from exhausting isometric muscular exercise was found to be greater in unstable postpolio subjects than stable postpolio or control subjects. The cause for this finding is unknown and requires further investigation.

Adult↗