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Query: UMLS:C0015672 (fatigue)
 51,768 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two men with T7 and T12 complete traumatic lesions have received implants to stimulate the femoral nerves and (in the T7 case) the inferior and superior gluteal nerves. By using these continuously at 13 pulses/sec they can stand and walk, as other paraplegics do with calipers. Regular stimulation at 11 or 13 pulses/sec greatly increases the force exerted by the quadriceps femoris muscles and their resistance to fatigue, and this improvement is not lost during 2 months without stimulation.
Paraplegia 1979 Feb
PMID:Electrical splinting of the knee in paraplegia. 31 10

When performing forward trunk flexion, cervical cord injured (CCI) patients exhibit continuous and high EMG activity in the diaphragm and elevated abdominal pressures. This study addressed the question whether the trunk flexion manoeuvres cause such a high force development in the diaphragm that this muscle shows EMG signs of fatigue. Six patients with complete cervical cord lesions were tested sitting in their own wheelchairs. The tension-time indices obtained when patients were sitting in a relaxed position were moderately to markedly higher than in normal subjects. The force developed during trunk flexion averaged 30% of the maximal transdiaphragmatic pressure and was accompanied by clear EMG findings of diaphragmatic fatigue in all patients except one. The acute diaphragmatic load in certain CCI patients may well produce ischaemia and increase the risk of tissue impairment. Therefore, there appears to be a need for differing strategies in the short and in the long term treatment of CCI patients; longitudinal evaluation of main diaphragmatic function may be useful for an adequate amount of respiratory muscle training.
Paraplegia 1992 Sep
PMID:Electromyographic registration of diaphragmatic fatigue during sustained trunk flexion in cervical cord injured patients. 140 45

In order to assess the effects of FES on muscle output, chronic electrical stimulation of the quadriceps muscle was applied for half an hour twice a day for 2 months, in 10 thoracic level traumatic paraplegic patients. Results concerning torque (at 6 different muscle lengths) and fatigue were measured using a strain gauge transducer in isometric condition, and compared with the findings in 15 paraplegic patients who had not received electrical stimulation, and with 10 able bodied subjects with normal motor functions. With training, muscle strength was very significantly improved whilst fatigue resistance remained at a low level. The peak torque was not found to be of the same muscle length when comparing paraplegics and control subjects; it seemed to demonstrate that length-tension relationship of the muscular actuator was changing when it was electrically activated. Moreover, the force recorded in paraplegics remained markedly lower than in able bodied people.
Paraplegia 1992 Jul
PMID:Effects of functional electrical stimulation (FES) on evoked muscular output in paraplegic quadriceps muscle. 150 60

Seasonal Affective Disorder (SAD) has received formal research attention only within the last eight years. Diagnostic criteria for SAD include many characteristics typical of depression: sadness, low self-esteem, lack of energy, social withdrawal, and suicide ideation, and features of atypical depression: carbohydrate craving, overeating, weight gain, and hypersomnia. Differential diagnosis of the disorder depends on an onset in fall/winter and remission in spring/summer. It was hypothesized that spinal cord injury (SCI) patients would have a higher incidence of the disorder in the northern latitudes because of decreased outdoor activities in winter and because of such light-depriving winter survival tactics as installing opaque plastic for storm windows. SCI patient responded to a postal survey which included Rosenthal's Seasonal Pattern Assessment Questionnaire (SPAQ) and the Beck Depression Inventory (BDI). Results showed a substantially higher rate of SAD among SCI patients than in the normative sample.
J Am Paraplegia Soc 1992 Apr
PMID:Seasonal affective disorder in a spinal cord injury population. 158 5

In 1984, researchers analyzed data on 231 18-45 year old women with a spinal cord injury who underwent initial rehabilitation at Craig Hospital in Englewood, Colorado to examine sexual issues. More than 50% of the women reported that health workers did not provide them sufficient sexuality information during rehabilitation, but those who underwent rehabilitation after 1977 were more satisfied with it than those before 1977. They tended to be satisfied with the care they received from their physicians after the injury. Most women were comfortable talking about sexuality with family, friends, and/or other women with spinal cord injuries. Some women were concerned with increases in vaginal discharges (53%) and perspiration (27%) after the injury. Clinicians must realize that the needs of women with spinal cord injuries are different than those of men. Spasticity during sexual relations, pregnancy, childbirth, and the postpartum period troubled some women, e.g., it interfered with sexual intercourse in 21% of the women. Yet 2 newborns were addicted to valium which is used to control spasticity. Other issues were self-confidence and lack of spontaneity. Nevertheless 69% of all women were satisfied with sexual experiences. 60% of the women had amenorrhea after their injury and the mean time for menses resumption was 5 months. The preinjury pregnancy rate was 1.3/person compared with only .34 after the injury. Women with incomplete paraplegia had a higher postinjury pregnancy rate than those with complete quadriplegia (.63 vs. .15; p.001). 50% of the 47 women who had full-term infants delivered vaginally. 49% did not use any anesthesia. Pregnancy complications and complications during labor and delivery were bladder and bowel problems, autonomic hyperreflexia, decubitus ulcers, urinary tract infections, edema, anemia, spotting, fatigue, cardiac irregularity, and preeclampsia.
Paraplegia 1992 Mar
PMID:Sexual issues of women with spinal cord injuries. 163 Aug 47

This study describes the responses of 20 paraplegic athletes (mean age: 26.8 +/- 1.6 years) to a continuous incremental workload test until exhaustion on an arm cranking ergometer (ACE) and on a wheelchair ergometer (WCE). Both ergometers used the same electromagnetic braking device allowing a fair comparison between results. Tests were conducted at a 24 hour interval at the same time of the day. Oxygen uptake (VO2), heart rate (HR), workload (W), blood pressure (BP), Borg index, and mechanical efficiency (ME) were measured at every minute during the effort and the cool down periods of both tests. The purpose of this study was to analyse the different responses obtained on ACE and on WCE during maximal effort by paraplegics, and also to determine which ergometer permits the higher ME. Results indicate that paraplegics reached the same max HR on ACE and on WCE (97% of the predicted max HR). The lack of significant difference (p less than 0.05) between ACE and WCE in terms of maximal values of VO2, VE and HR suggests that the subjects reached their maximal capacity on each test regardless of the type of ergometer. Nevertheless, W max (in Watts) was 26% higher on ACE than on WCE. Maximal ME values were respectively 16% and 11.6% on ACE and WCE. Results suggest that ergometers and protocol used in this study are appropriate to measure physiological responses of paraplegic athletes during arm cranking and wheelchair exercise without excessive or early arm fatigue.
Paraplegia 1991 Sep
PMID:Physiological responses to maximal exercise on arm cranking and wheelchair ergometer with paraplegics. 178 11

This study examined the test-retest reliability of peak physiological responses during wheelchair ergometry (WE) in individuals with spinal cord injury (SCI). Seven wheelchair dependent subjects, two with paraplegia (T10-11 and T11-12 lesions) and five with quadriplegia (all with C6-7 lesions), were given two incremental exercise tests to volitional fatigue on separate occasions within a one-week period. Each subject wheeled his or her personal wheelchair, which was mounted on a set of frictionless rollers with side-mounted flywheels. Metabolic and cardiorespiratory responses were continuously monitored by means of an automated metabolic measurement cart interfaced with an electrocardiograph. Statistical analysis revealed no significant differences (p greater than .05) between the mean values of the two test trials for six peak values. Reliability coefficients (p less than .01) were: oxygen uptake (0.98), heart rate (0.97), ventilation volume (0.96), respiratory exchange ratio (0.91), oxygen pulse (0.96), and ventilatory equivalent for oxygen (0.88). The investigators concluded that these six physiological responses in subjects with SCI undergoing WE are highly reliable, and that these variables can be used in the objective prescription, monitoring, and evaluation of exercise rehabilitation programs for individuals with SCI.
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PMID:Reliability of peak physiological responses during wheelchair ergometry in persons with spinal cord injury. 205 32

The purposes of this study were three-fold: (a) to determine acute physiologic responses of spinal cord injured (SCI) subjects to peak levels of leg cycle ergometry utilizing functional neuromuscular stimulation (FNS) of paralyzed leg muscles, (b) to determine the relative contributions of passive and active components of FNS cycling to the peak physiologic responses, and (c) to compare these physiologic responses between persons who have quadriplegia and those who have paraplegia. Thirty SCI subjects (17 quadriplegics and 13 paraplegics) performed a discontinuous graded FNS exercise test from rest to fatigue on an ERGYS 1 ergometer. Steady-state physiologic responses were determined by open-circuit spirometry, impedance cardiography with ECG, and auscultation. In the combined statistics of both groups, it was noted that peak FNS cycling significantly increased (from rest levels) mean oxygen uptake by 255%, arteriovenous O2 difference VO2 and VE, Q and a-vO2 and VCO by 69%, and stroke volume by 45%, while total peripheral vascular resistance decreased by 43%. Mean peak power output for paraplegics (15 W) was significantly higher than for quadriplegics (9 W), eliciting higher peak levels of pulmonary ventilation and sympathetically mediated hemodynamic responses such as cardiac output, heart rate, and systolic and diastolic arterial blood pressure. Passive cycling without FNS produced no statistically significant increases in physiologic responses above the resting level in either group.
J Am Paraplegia Soc 1990 Jul
PMID:Physiologic responses of paraplegics and quadriplegics to passive and active leg cycle ergometry. 223 Jul 94

Single extracellular action potentials have been recorded at 2 sites from human S4 ventral nerve roots, and their amplitude, duration and conduction time measured. Conduction velocity frequency distribution histograms have been constructed. Three classes of a-motoneurons could be identified, which had mean conduction velocity values of 61.5 (a1), 49 (a2) and 37.5 m/sec (a3) for a young adult at about 37 degrees C. The conduction velocity of single motor fibres has been correlated with its action potential amplitude and duration. The action potential amplitude increased and the duration decreased with the conduction velocity. Touch-stimulated and other afferences have been identified in these motor roots. The fastest afferents had about the same conduction velocity as the a1-motoneurons and the touch-stimulated afferents had conduction velocities of between 20 and 41 m/sec at about 34 degrees C. Also the amplitude of the afferent single unit potentials increased and the duration decreased with the conduction velocity. The electrophysiologically measured roots have been removed and morphologically analysed with the light and electron microscope. Nerve fibre diameter frequency distribution histograms have been constructed with respect to 4 myelin sheath thickness ranges. In the diameter histograms 3 a-motoneuron peaks with mean values of about 12.5 (a1), 10.3 (a2) and 8.3 microns (a3) and 1 peak of touch stimulated afferences with a mean value of 11.2 microns could be identified for myelin sheath thicknesses between 1.8 and 2.3 microns. A teased fibre dissection gave a factor of 100 between the internode length and the nerve fibre diameter. The electrophysiologic parameters have been correlated with the morphologic parameters. Approximate factors between the mean conduction velocities and the mean nerve fibre diameters of the a-motoneuron classes were 5.1 (a1), 4.85 (a2) and 4.4 m/sec/microns (a3) at about 37 degrees C. Comparable approximate conversion factors for group I and fastest touch-stimulated ventral root afferents were 4.5 (gr. I) and 3.5 m/sec/microns (touch). By comparing the number of nerve fibres of each class of motoneurons with the number of spontaneously occurring action potentials, it was found that the a3-motoneurons, most likely supplying the slow fatigue resistant muscle fibres, had the highest activation at rest. The existance of ventral root afferents has been discussed with respect to pain treatments by deafferentation and ventral root stimulation to improve the bladder function in paraplegia.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Efferent and afferent fibres in human sacral ventral nerve roots: basic research and clinical implications. 264 71

Single extracellular nerve action potentials from afferent fibres with various functions were recorded from human sacral nerve roots. It was shown that the potentials from these fibres can have different wave forms (amplitude, duration) and conduction velocities. The smaller potentials with longer durations have lower cut-off frequencies for certain identification than the larger potentials of shorter duration. The conduction velocity diagnosis covers a range of velocities with a factor of about 10. The slowest measured conduction velocities were between 4 and 10 m/sec. The identification of the functions of afferents in nerve roots is possible by calculating conduction velocities and stimulated activity increase measurements. Besides touch and pain fibres from the skin, afferents from mechano-receptors of the urinary bladder and the anal canal could be detected in dorsal sacral roots. There is evidence of motoneurons in the dorsal sacral roots supplying fatigue resistant muscle fibres. Sacral nerve root electrodiagnosis can be used in operations to identify physiologically-stimulated afferents and reflex activated motoneurons and, therefore, possibly will be useful in nerve anastomoses and nerve root stimulations in paraplegia.
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PMID:Electrodiagnosis of human dorsal sacral nerve roots by recording afferent and efferent extracellular action potentials. 281 54


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