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Biomedical subjects

R T Katz

Publications and source records attributed to R T Katz.

29 records · Page 2Linked to original sources
PubMed1989

Spastic hypertonia: mechanisms and measurement.

Spastic hypertonia has been defined as a motor disorder characterized by a velocity-dependent increase in tonic stretch reflexes (muscle tone) with exaggerated tendon jerks, resulting from hyperexcitability of the stretch reflex, as one component of the upper motor neuron syndrome. Heightened muscle tone may be the result of changes intrinsic to the muscle or to altered reflex properties. Increased motoneuronal excitability and/or enhanced stretch-evoked synaptic excitation of motoneurons are mechanisms that might enhance stretch reflexes. Two distinct parameters may be altered in the pathologic stretch reflex--the "set point," or angular threshold of the stretch reflex, and the reflex "gain," or the amount of force required to extend the limb in proportion to the increasing joint angle. Earlier studies fail to dissociate the contributions of reflex threshold and reflex gain. Recent investigations suggest that spastic hypertonia may be the result of a decrease in stretch reflex threshold without significant increase in reflex gain, as was previously believed. Various clinical scales, biomechanical paradigms, pendulum models, and electrophysiologic studies have been used to quantify spastic hypertonia. Biomechanical methods seem to correlate most closely with the clinical state. Spastic hypertonia is but one component of the upper motor neuron syndrome, whose features also include loss of dexterity, weakness, fatigability, and various reflex release phenomena. These other features of the upper motor neuron syndrome may well be more disabling to the patient than changes in muscle tone.

Humans↗
PubMed1988

Rehabilitation outcomes in complete C5 quadriplegia.

Establishment of rehabilitation goals for spinal cord injury patients generally has been based on the degree of residual motor function. Despite extensive clinical experience with spinal cord injury rehabilitation, there have been no reports of the ability of C5 quadriplegic patients to perform self-care and mobility skills before and after rehabilitation. This study was designed to examine the rehabilitation outcomes of 63 patients with C5 complete quadriplegia, who completed an interdisciplinary inpatient rehabilitation program, using the 100-point modified Barthel Index as a means of rating functional status. There were statistically significant increases in the mean modified Barthel index scores from 7.1 on admission to 28.9 on discharge for the entire group of patients. The self-care subscore increased significantly from 6.5 on admission to 20.0 on discharge and the mobility subscore increased significantly from 0.5 on admission to 8.9 on discharge. Ability to perform self-care and mobility subscore tasks is described. This study documented significant improvements in function during comprehensive rehabilitation among patients with C5 spinal cord injury.

Activities of Daily Living↗
PubMed1988

Management of spasticity.

The functional impairment due to spasticity must be carefully assessed before any treatment is considered. Therapeutic intervention is best individualized to a particular patient. Basic principles of treatment to ameliorate spastic hypertonia are: 1) avoid noxious stimuli and 2) provide frequent range of motion. Therapeutic exercise, cold or topical anesthesia may decrease reflex activity for short periods of time in order to facilitate minimal motor function. Casting and splinting techniques are extremely valuable to extend joint range diminished by hypertonicity. Baclofen, diazepam and dantrolene remain the three most commonly used pharmacologic agents in the treatment of spastic hypertonia. Baclofen is generally the drug of choice for spinal cord types of spasticity, while sodium dantrolene is the only agent which acts directly on muscle tissue. Phenytoin with chlorpromazine may be potentially useful if sedation does not limit their use. Tizanidine and ketazolam, not yet available in the United States, may be significant additions to the pharmacologic armamentarium. Intrathecal administration of antispastic medications allows high concentrations of drug near the site of action, which limits side effects. This form of treatment is the most exciting recent development in the treatment of spastic hypertonia. Peripheral electrical stimulation may have limited use in diminishing tone and facilitating paretic muscles. Dorsal column stimulation via electrodes within the spinal column was initially hailed as a therapeutic advance, but has subsequently been shown to be minimally effective. Phenol injections provide a valuable transition between short-term and long-term treatments and offer remediation of hypertonia in selected muscle groups. Tenotomies and tendon transfers offer significant benefit in carefully chosen patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Baclofen↗
PubMed1987

Benefits of rehabilitation for traumatic spinal cord injury. Multivariate analysis in 711 patients.

The functional outcomes of 711 patients with traumatic spinal cord injuries who were admitted to a rehabilitation hospital during an eight-year period were studied. The modified Barthel index, a 100-point scale, was used to assess ability to perform self-care and mobility skills at rehabilitation admission and discharge. There were statistically significant improvements in self-care and mobility subscores of the modified Barthel index. Mean total modified Barthel index scores increased from 13.8 at admission to 46.1 at discharge for patients with quadriplegia, and from 37.7 to 74.4 for patients with paraplegia. Functional gains made by patients with incomplete spinal lesions were greater than those made by patients with complete lesions. This study documents improvement in ability to perform self-care and mobility skills among patients with spinal cord injuries who participate in comprehensive rehabilitation.

Adult↗
PubMed1987

Mortality and complications of the locked-in syndrome.

The locked-in syndrome is a severe disability consisting of quadriplegia and anarthria with preserved consciousness. No large series of cases have been reported and very few cases of long-term survival have been described. We present a follow-up of 27 patients "locked-in" for more than one year. Twenty-four were still alive up to 12.5 years after onset, with a mean survival of 4.9 years. Significant recovery was noted in only a few patients. Seventeen patients lived at home at the time of study. Eight were never hospitalized after the initial event. Gastrostomy and tracheostomy tubes and indwelling catheters were eventually removed from many patients. Electronic devices were used by ten patients to facilitate communication. We conclude that rehabilitation and medical care must be planned carefully, given the length of survival shown in this group.

Adult↗
PubMed1987

Functional electric stimulation to enhance systemic fibrinolytic activity in spinal cord injury patients.

Functional electric stimulation (FES) of muscle has been used to decrease the incidence of postoperative deep vein thrombosis (DVT) in neurologically intact individuals. This study was undertaken in order to determine whether a large-scale trial should be initiated using FES to prevent DVT in spinal cord injury (SCI) patients. The goals of this pilot study were to demonstrate the value of FES of calf musculature in (1) increasing plasma fibrinolytic activity and (2) promoting venous blood flow in the lower extremities. Plasma fibrinolytic activity was monitored in ten SCI patients before, immediately after, and 100 minutes after 60 minutes of calf FES. A significant increase in plasma fibrinolytic activity was noted using whole blood and platelet-rich plasma clot lysis assays. Continuous photoplethysmographic and Doppler ultrasound monitoring of venous flow was attempted during FES in four spinal cord patients, and a mild to moderate increase in flow was achieved. FES was not as successful as manual compression in promoting venous emptying of the lower extremity. FES may be a useful tool in the prevention of DVT in SCI patients due to a significant increase in fibrinolytic activity and a mild to moderate increase in venous blood flow. FES merits full-scale clinical evaluation for this purpose.

Electric Stimulation Therapy↗
PubMed1986

Seizures secondary to autonomic dysreflexia.

Seizures are a little-recognized component of the syndrome of autonomic dysreflexia. Three patients who exhibited seizures during episodes of dysreflexia independent of intracerebral pathology are described. The presence of seizures in patients with traumatic myelopathy T-6 should alert the physician to a possible dysreflexic episode, and measures should be taken to avert such an episode.

Adult↗
PubMed1985

Glucose oxidase sticks and cerebrospinal fluid rhinorrhea.

The recognition of cerebrospinal leakage from a fistula is an important consideration for any physician caring for a head-injured population. Several procedures including radiographic, intrathecal dye, nuclear medicine tracer studies, computerized tomography with metrizamide injection, and immunological fixation have been reported to help in the diagnosis. Introduction of glucose oxidase test sticks has been traditionally touted to be a reliable bedside indicator of CSF rhinorrhea; this case study demonstrates a falsely negative result from glucose oxidase sticks.

Adult↗
PubMedDate not supplied

Functional improvement in severe head injury after readmission for rehabilitation.

Early rehabilitation has been shown to minimize complications and optimize functional outcomes in head-injured patients. Although cognitive, behavioural and vocational issues continue for years after injury, many investigations maintain that physical improvement is limited after 6 months. At 12 months after injury, expectations for physical improvement are generally limited. In addition, although repeated inpatient admissions for rehabilitation are common, gains in self-care and mobility skills during readmissions for rehabilitation have not been specifically investigated. In this retrospective study the records of 49 severely head-injured patients were evaluated. All were readmitted to an inpatient rehabilitation facility more than 12 months after injury. Barthel Index scores were obtained to evaluate physical function. Although previous studies would predict few improvements, in this study 53% (26 patients) showed improvement, and the difference between readmission and discharge Barthel scores was statistically significant (p = 0.0001). Gains were highly correlated with length of readmission, but not with age of patient, age at time of injury, length of coma, time since injury, or duration of previous rehabilitation. Patients with mid-range admission Barthel scores (21-85) demonstrated the largest gains, with 79% showing improvement. Gains averaged 11.2 points on the Barthel Index. Severely head-injured patients may show clinically significant improvement in physical function well after current standards predict a plateau.

Activities of Daily Living↗
PubMedDate not supplied

Impairment and disability rating in low back pain.

This "how-to" guide for the examination of impairment and disability resulting from low back pain examines Workers' Compensation, Social Security, The Americans with Disabilities Act, and the American Medical Association's Guides to the Evaluation of Permanent Impairment. The medicolegal interface is addressed, and specific recommendations are made to assist the physician involved in an independent medical evaluation.

Back Injuries↗