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Biomedical subjects

A A Rodriquez

Publications and source records attributed to A A Rodriquez.

At least 37 records · Page 2Linked to original sources
PubMed1991

Electrophysiologic study of the quadriceps muscles during fatiguing exercise and recovery: a comparison of symptomatic and asymptomatic postpolio patients and controls.

This study was performed to determine whether deficits in muscle strength, work capacity, and ability to recover strength after exhaustion in symptomatic postpolio subjects were due to central inhibition (lassitude) or other physiologic differences. We studied 34 symptomatic polio subjects, 16 asymptomatic polio subjects, and 41 control subjects. Root mean squared electromyography (RMS-EMG) and the median frequency (Fm) of the power spectrum of the quadriceps muscle was determined with surface electrodes during maximal volitional contraction (MVC) of isometric knee extension, an endurance test to exhaustion at 40% of maximal torque, and strength recovery testing that was performed at regular intervals for 10 minutes postexhaustion. Initial Fm during MVC and during the 40% MVC endurance test were similar in all three groups. The Fm decreased during the endurance test and increased during recovery similarly in all three groups. The RMS-EMG also changed in parallel fashion in all three groups during the same procedures. During recovery, a similar degree of RMS-EMG facilitation was seen in all three groups. Thus, reduction in strength, work capacity, and ability to recover from fatiguing exercise do not appear to be related to central factors (lassitude); they are probably related to other factors, such as local muscle fatigue. Each group appears to fatigue and recover in a similar manner electrophysiologically, although symptomatic polio subjects have a deficit in strength recovery, apparently due to local muscular fatigue.

Electrophysiology↗
PubMed1991

Neuromuscular function in polio survivors at one-year follow-up.

Many polio survivors complain of progressive loss of strength, work capacity, endurance, and ability to recover from fatiguing activity. These variables were measured initially and one year later in the quadriceps muscles of 28 symptomatic and 16 asymptomatic persons who had polio and 38 control individuals. Peak knee extension torque was measured isokinetically and isometrically. Endurance, or the amount of time the subject could maintain isometric torque at 40% of maximal torque, was measured. Work capacity was determined as the product of isometric torque and endurance time. Recovery of strength was measured at regular intervals for ten minutes after the endurance test. Statistical analysis was done by repeated measures ANOVA. Although the initial measures showed significant deficits in mean peak torque, work capacity, and recovery of strength in symptomatic postpolio subjects, no significant changes were found one year later in any of the variables. We conclude that symptomatic postpolio subjects do not lose significant neuromuscular function in one year.

Adult↗
PubMed1991

Physiologic parameters and perceived exertion with local muscle fatigue in postpolio subjects.

Fifty postpolio patients, 34 with and 16 without complaints of progressive loss of muscle strength, and 41 control subjects were studied to compare physiologic measures of the fatiguing process and to determine whether there is a significant interaction between the rating of perceived exertion (RPE) and physiologic measures. Statistical analyses were by ANOVA and repeated-measures ANOVA. The RPE was obtained every 20 seconds during an isometric contraction of the quadriceps at 40% of maximal torque; median frequency (Fm) of the power spectrum of the surface electromyographic signal and neuromuscular efficiency (NME) were constantly monitored. The RPE increased similarly (p greater than .05), whereas Fm and NME decreased similarly (p greater than .05) during endurance exercise at 40% of maximal torque in all three groups. A significant (p less than .05) interaction was found between RPE and both Fm and NME. We conclude that physiologic measures of the fatiguing process (Fm and NME) occur in a similar manner in postpolio and control subjects and that there is a significant interaction between subjective RPE and physiologic measures of the fatiguing process.

Electromyography↗
PubMed1990

Plasma lipid and lipoprotein concentrations in symptomatic postpolio patients.

This study reports lipid and lipoprotein concentrations in postpolio patients seen in our postpolio clinic who were evaluated for complaints of progressive weakness, fatigue, and/or pain. Concentrations of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG) were determined after an overnight fast. Sixty-four patients (24 men and 40 women) with a mean age of 48 +/- 10 years were studied. Mean (+/- SD) lipid concentrations (mg/dL) for men and women, respectively, were 220 +/- 46 and 213 +/- 43 for TC; 38.5 +/- 8.6 and 59.1 +/- 18.1 for HDL-C; 148 +/- 46 and 129 +/- 36 for LDL-C; and 205 +/- 107 and 105 +/- 55 for TG. Hyperlipidemia was found in 16 of 24 men and 10 of 40 women. In the men, mean HDL-C concentration was in the lowest decile of our hospital laboratory's reference range, whereas mean TC/HDL-C ratio was elevated above the recommended value. It is suggested that lipid and lipoprotein concentrations be evaluated in postpolio patients because a high prevalence of lipid/lipoprotein disorders was found in our subjects. Further research is needed on this topic.

Adult↗
PubMed1990

Neuromuscular function: comparison of symptomatic and asymptomatic polio subjects to control subjects.

The purpose of this study was to determine if there were any differences between symptomatic and asymptomatic polio survivors by history of acute poliomyelitis illness, electromyographic evidence of terminal motor unit reorganization, and neuromuscular function of the quadriceps femoris muscle. Thirty-four symptomatic postpolio subjects, 16 asymptomatic postpolio subjects, and 41 controls were studied. A questionnaire assessed polio history. Peak knee extension torque was measured isokinetically and isometrically. Endurance (time to exhaustion) was measured at 40% of maximal isometric torque. Work capacity was determined as the product of torque and duration. Recovery of isometric strength was measured at regular intervals for ten minutes after exhaustion. Quantitative electromyography was also performed on the quadriceps to determine motor unit action potential duration and amplitude. It was found that symptomatic subjects had evidence of more severe original polio involvement by history (documented electromyographically), were weaker and capable of performing less work than asymptomatic subjects, and recovered strength less readily than controls.

Adult↗
PubMed1990

Laryngeal electromyography in the diagnosis of laryngeal nerve injuries.

A practical technique of electromyographic (EMG) sampling of the cricothyroid and thyroarytenoid (vocalis) muscles is described. Quantitative motor unit action potential (MUAP) analysis on a group of seven healthy subjects revealed a mean amplitude of 426 microV for the vocalis and 500 microV for the cricothyroid muscle. Mean MUAP duration for the vocalis muscle was 3.5 msec and 4.4 msec for the cricothyroid. Normal activation patterns are reviewed for each muscle. The results of EMG studies in 18 consecutive patients referred to the EMG laboratory with chronic hoarseness was reviewed. There was good agreement between findings at laryngoscopy and EMG, although more widespread involvement was seen on EMG than was suspected on the basis of laryngoscopy. Vocal cord immobility (apparent paralysis) was not usually accompanied by the total absence of MUAPs. The procedure was well tolerated without local anesthesia and provides information about peripheral nerves which may be of prognostic value.

Action Potentials↗
PubMed1989

Psychologic characteristics of polio survivors: a preliminary report.

Ninety-three men and women with histories of polio were administered the Symptom Check List-90 Revised (SCL-90R), Psychosocial Adjustment to Illness Scale-Self Report (PAIS-SR), and a questionnaire about their polio histories. The SCL-90R and PAIS-SR are measures of emotional and psychosocial functioning. Two samples were used: a clinic sample (n = 71) and a postpolio support group sample (n = 22). Initial results for both on the SCL-90R and PAIS-SR indicated elevated scores on a number of subscales. SCL-90R subscale elevated scores for men included those for somatization, depression, anxiety, hostility, and phobia, whereas for women there were elevations on measures of somatization, depression, anxiety, and psychoticism. Elevations were found in the following subscales on the PAIS-SR (pooling men and women): health care orientation, social environment, and extended family relationships. Men scored slightly, but not significantly, higher than women in the SCL-90R except for the hostility subscale, in which the difference was significant (p less than 0.05). Symptom profiles indicated psychologic distress. Comparisons with variables associated with polio and its late effects (such as severity of initial polio, use of an iron lung during initial illness, number of involved limbs, etc) were not statistically significant.

Attitude to Health↗
PubMed1989

Symptoms and clinical impressions of patients seen in a postpolio clinic.

A retrospective study was performed to identify symptoms and clinical findings in postpolio patients seen in a postpolio clinic. Charts of 79 consecutive patients (28 men and 51 women) with histories and examinations compatible with the diagnosis of poliomyelitis were reviewed. The average current age of our patients was 47.3 +/- 10.4 years; the average age at onset of acute polio was 10.4 +/- 9.4 years; and the average number of years since function was first noticed to decline was 7.8 +/- 6.4 years. The most common symptoms acknowledged were progressive weakness (87%), muscle pain (86%), fatigue (86%), decreased activity level (78%), joint pain (77%), and back pain (70%). The clinical impression in most of these patients was arthritis/arthralgia (71% of the patients) or muscle overuse or myofascial pain (71%). Eleven (14%) had evidence of nerve compression, although 39% complained of sensory loss. Five patients had respiratory problems that required evaluation. Recommendations proved helpful for 78% of those seen at follow-up. These recommendations included pacing, energy conservation (planning, use of wheelchair or motorized scooter), gentle stretching or strengthening exercise, use of orthotic devices, weight loss or nutritional counseling, gentle aerobic exercise, use of a cane, and use of adaptive equipment.

Activities of Daily Living↗
PubMed1987

Somatosensory evoked potentials from dermatomal stimulation as an indicator of L5 and S1 radiculopathy.

Dermatomal somatosensory evoked potential (DSEP) results for L5 and S1 were contrasted with electromyography (EMG) results for 50 patients referred to the electrodiagnosis laboratory to document the presence of radiculopathy. Stimulation sites were over the dorsum of the foot at the distal fifth metatarsal for the S1 dermatome and at the web space of the first and second toe for the L5 dermatome. Recordings were made at PZ reference to FZ. Spinal cord or cauda responses could not be detected. Both EMG and DSEP were contrasted to myelography or lumbar computerized tomography results on 31 patients. Side-to-side amplitude differences proved too variable to be of use. Sixty-five percent of abnormal DSEP results were on the basis of side-to-side latency criterion, and 35% were on the basis of an absent unilateral response. When compared to EMG and anatomic studies DSEP showed less accuracy and sensitivity. The specificity of the two tests was similar. Using both positive EMG and anatomic studies to define radiculopathy, there were 27% false negative tests and 9% false positive tests. An 86% root level correlation was found between EMG and DSEP. Dermatomal somatosensory evoked potential studies add little to the diagnosis of radiculopathy.

Adult↗
PubMed1979

Detrusor muscle and sphincteric response to anorectal stimulation in spinal cord injury.

Twelve patients with spinal cord injuries were studied to determine whether the anal sphincter could be used as an index of urethral sphincter activity and to determine the bladder and striated sphincter response to anal and rectal stimulation. Electromyogram (emg) needle electrodes were placed in the external urethral sphincter, external anal sphincter and levator ani. The output of a cystometer was simultaneously recorded on the printout so that the relationship of the striated muscle response to distension of the bladder could be observed. The response to inserting a finger into the external anal canal, external anal sphincter stretch and rectal balloon distension was also observed. The external urethral and anal sphincter activity was closely linked during bladder contraction and anorectal stimulation. The levator ani showed divergent activity. Stretch of the external anal sphincter caused an initial period of increased striated muscle activity, then in 10 of 12 patients abrupt and often marked inhibition of both sphincters and levator ani developed with continued stretch. Ongoing bladder contractions were inhibited and a decrease in bladder tone developed in 7 of 12. Stretch of the rectum produced results similar to those with anal stretch except that bladder facilitation was seen in 4 of 12 patients.

Anal Canal↗
PubMed1978

Electromyogram-gas cystometrogram: its use in the management of neurogenic bladder of spinal cord injury.

The electromyogram (emg)-gas cystometrogram was used to study spinal-cord-injured patients with indwelling catheters before trial of voiding (TOV) to remove an indwelling catheter. Twenty-four patients were studied during 27 consecutive admissions. A coaxial needle electrode was placed in the external urethral sphincter. The output of a cystometer was simultaneously recorded on the emg printout so that the relationship of the shpincter response to distention of the bladder could be observed. Of 10 patients without bladder contractions, 7 had active urethral sphincters and 6 of these failed to achieve less than 50 ml residual thereby failing the TOV. The seventh patient succeeded in the trial and on subsequent study was found to have developed bladder contractions with a coordinated bladder-sphincter synergy. The 3 patients without bladder contractions or sphincter activity succeeded in their TOV using Credé's method. Seventeen patients with bladder contractions were divided into synergic, nonsynergic and partially synergic patterns. The 3 patients with synergic patterns succeeded in their TOV. Thirteen of 14 nonsynergic or partially synergic patients failed the TOV. The 1 nonsynergic patient who succeeded had bladder contractions of 70 cm of water compared to a mean of 28 cm of water for all other patients with bladder contraction. The emg-gas cystometrogram was helpful in selecting those patients who were successful in removing the Foley catheter. Important factors governing success in the multiple effort trial of voiding were the amplitude of the detrusor contraction, the presence of detrusor-sphincter synergy and the presence of a flaccid sphincter.

Catheters, Indwelling↗
PubMedDate not supplied

Low-intensity, alternate-day exercise improves muscle performance without apparent adverse effect in postpolio patients.

The purpose of this study was to examine the effect of a low-intensity, alternate-day, 12 wk quadriceps muscle-strengthening exercise program on muscle strength and muscle and motor unit integrity in 12 postpolio patients. Patients performed six to ten repetitions of a 5-s duration knee extension exercise with ankle weights. After completing six repetitions, patients rated the perceived exertion (RPE) in the exercised muscle. The patient continued repetitions until RPE was >/= 17 or ten repetitions were performed. The weight was increased the next exercise day whenever the RPE was < 17 after ten repetitions. Before and after the training program, median macroamplitude as well as jitter and blocking were determined electromyographically (EMG), serum creatine kinase (CK) was measured, and quadriceps muscle strength was assessed. The ankle weight lifted after 2 wk of training and at the end of the program were also recorded. Although the ankle weight lifted at the end of the program significantly (P < 0.05) increased from a mean +/- SD of 7.1 +/- 2.7 to 11.2 +/- 4.7 kg, the dynametrically determined muscle strength measures did not significantly (P > 0.05) increase. The EMG and the serum CK variables also did not significantly (P >0.05) change as a result of the exercise program. We conclude that performance was improved, as demonstrated by an increase in the amount of weight the patients lifted in the exercise program. No evidence was found to show that this program adversely affected the motor units or the muscle as the EMG and CK did not change.

Adult↗
PubMedDate not supplied

Neuromuscular and psychological characteristics in subjects with work-related forearm pain.

There are scant data available on the neuromuscular and psychological characteristics of patients with cumulative trauma disorders. We compared 16 subjects with work-related forearm and hand pain in the dominant upper limb with 9 age-matched control subjects. Pain subjects were divided into two groups based on nerve conduction studies: eight subjects were in the study group for median neuropathy at the wrist (MN, median transcarpal latency >2.3 ms), and eight were in the study group for electrodiagnostically negative pain (EN). Average pain, forearm muscle tenderness, grip strength, pinch strength, and wrist flexor and extensor strength were measured. The Health Status Questionnaire and the Beck Depression Inventory were used to measure health perception and depressive symptoms, respectively. Work satisfaction was determined by a newly devised scale. Statistical analysis was by analysis of variance and planned comparison analysis. The MN and EN groups did not significantly differ on any of the measures except median transcarpal latency. Both pain groups had significantly (P < 0.05) greater average pain, greater extensor muscle tenderness, higher Beck Depression Inventory scores, higher pain rating, and poorer physical functioning on the Health Status Questionnaire than did the normal control group. Grip strength and wrist extension force were diminished in both cumulative trauma groups compared with control subjects; however, only grip strength in the MN group and wrist extension force in the EN group differed significantly (P < 0.05) from control subjects. Only the EN group had significantly less work satisfaction than did the control group. Overall, both pain groups differed from control subjects and shared similar characteristics, with the exception of median neuropathy.

Adult↗
PubMedDate not supplied

Botulinum toxin injection of spastic finger flexors in hemiplegic patients.

OBJECTIVE: To assess the outcomes of botulinum toxin injection of spastic finger flexors followed by intensive training of finger extensors. DESIGN: Fourteen subjects with chronic hemiplegia spasticity of the upper limb had electromyographic-guided botulinum toxin injection into the long finger flexors. All patients presented with minimal active finger extension with the wrist flexed, sustained clonus of the finger flexors, functional proximal arm function, and absence of fixed contracture. Cadaver dissections directed selection of two injection sites: the flexor digitorum sublimis and the flexor digitorum profundus. Fifty mouse units of botulinum toxin were injected into each muscle. After injection, the subjects were instructed in a home program of stretching the long finger flexors, upper limb weight bearing with a weight-bearing splint, and exercise to improve finger extension control. RESULTS: Compared with preinjection measures, assessment the first week after the initial injection showed significantly reduced tone, reduced clonus, and greater active finger extension with the wrist in the neutral position. Four months later, the Ashworth scale increased to preinjection levels in the six subjects with repeated injections but was again decreased postinjection. Active finger extension with the wrist in the neutral position and clonus showed a statistically nonsignificant trend toward cumulative improvement after the second injection. CONCLUSION: The greatest change in finger extension and spasticity reduction occurred after the first injection. Continued significant improvement in finger extension was not observed.

Adult↗