Major U.S. disability and compensation systems graphically compared.

This article offers the reader a "bullet" overview of the principal systems of disability determination. The reader is referred to other sources for more in-depth coverage and a detailed historical background and overview of these systems.

Impairment and disability rating in low back pain.

LBP is one of the two most common forms of disability in Western society (mental illness is the other), and remains a thorny problem in the arena of disability evaluation. Disability evaluation after LBP differs whether the pain is work-related or not. If work-related, guidelines for disability evaluation differ by jurisdiction and type of employment (e.g., private vs. federal employee). When outside of the workplace, thresholds for disability differ between entitlement programs (Social Security Disability) and private insurance programs (long-term disability insurance). In the patient without obvious findings, the disability evaluating physician needs to be caring and compassionate and yet maintain an objective stance with the understanding that there may be significant psychosocial overlay in patients with nonobjective pain complaints. Although some would argue that objective independent medical evaluation is an oxymoron, psychiatrists have excellent training and perspective with which to do so. The patient suffering from catastrophic brain injury or spinal cord injury offers a useful contrast--on the most severe end of the disability spectrum--to the patient with persisting low back complaints but normal physical examination. As a society, we have to wisely manage the funds that comprise our social "safety net" in order to provide for persons with severe disability who cannot provide for themselves. It would then follow that patients with minor impairments/disabilities should receive minor (i.e., noninflated) ratings. Psychiatrists need to enable rather than disable their patients.

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.

Impedance plethysmography as a screening procedure for asymptomatic deep venous thrombosis in a rehabilitation hospital.

OBJECTIVE: Patients admitted for an inpatient rehabilitation treatment program almost uniformly have an elevated risk of deep venous thrombosis (DVT) and pulmonary embolism (PE). We assessed the value of impedance plethysmography (IPG) as a screening procedure for asymptomatic deep venous thrombosis in a series of patients admitted to our institution. DESIGN: Using a prospective observational study design, consecutive admissions to our facility for a period of almost one year were subjected to IPG within several days of admission. SETTING: The study site was a 60-bed hospital-based rehabilitation center. PATIENTS: Four hundred eighty-three consecutive patients were studied prospectively within several days of admission. Diagnoses included a variety of neurological disorders that resulted in significant weakness, intracranial surgery, orthopedic surgical procedures and fractures, joint replacements, and nonorthopedic postsurgical deconditioning. Three hundred eighteen patients were available for three-month follow-up. INTERVENTIONS: IPG was successfully completed in 301 patients. If IPG was positive, DVT was further assessed by duplex ultrasound (DU). When IPG and DU confirmed the presence of a DVT, administration of heparin and Coumadin was begun. MAIN OUTCOME MEASURES: Thirteen of 416 attempted IPG studies were positive for DVT, whereas DU confirmed the diagnosis in only 3 patients. RESULTS: Follow-up found that six patients developed DVT or PE before discharge from our institution; five patients developed DVT or PE after discharge. CONCLUSIONS: IPG has a poor yield as a screening tool for asymptomatic DVT on admission to an inpatient rehabilitation facility. The sensitivity and positive predictive value of IPG was too low to advocate its routine use in this setting.

Critical evaluation of clinical research.

This focused review contains a suggested core of material that will help residents or practicing physiatrists critically review research papers published in the medical literature. Before accepting the results of a clinical trial, physiatrists must critique the experimental methods and study design carefully to decide whether to include these new ideas into their clinical practice. Medical research relies on statistical methodology, and statistics pervade the medical literature. This article begins with an introduction to rudimentary statistics. Fortunately, most studies depend on a rather small body of statistical concepts. The elements of experimental design--clinical trials, randomization, single-subject design, meta-analysis, epidemiological studies--are presented in a concise review. Finally, the elements of statistics and experimental design are integrated into a step-by-step method strategy for reading the medical literature.

Carpal tunnel syndrome: a practical review.

Carpal tunnel syndrome is the most common focal entrapment syndrome. Forceful repetitive activity and vibration may be important workplace risk factors for carpal tunnel syndrome. Although systematic study has suggested that carpal tunnel syndrome is work-related, no clear "dose-response" curve has been found between the amount or severity of work and the incidence or severity of the syndrome. Nocturnal pain is a hallmark of the syndrome, and Phalen's test, the carpal compression test and the Flick test are useful indicators of the diagnosis. The most commonly used confirmatory test is the nerve conduction study, with or without electromyography. The primary care physician can treat many cases successfully with simple ergonomic modifications, splinting and steroid injections. Surgical therapy is reserved for recalcitrant cases and patients with more severe nerve impingement. In addition to traditional open procedures, carpal tunnel release may be performed endoscopically.

Sequelae of minor traumatic brain injury.

Minor traumatic brain injury is the most common type of traumatic encephalopathy, with approximately 290,000 to 325,000 new cases occurring each year. Recent research has suggested that both anatomic factors (acceleration-deceleration injury, contusions) and neurotransmitter factors (cholinergic systems) may contribute to the pathologic sequelae. Symptoms may be broadly categorized as physical, behavioral/affective, cognitive and integrative. Patients with mild brain injury may demonstrate significant attention and information-processing impairments in the absence of apparent neurologic problems. Most symptoms abate within the first few months, but a sizable subgroup of patients remain symptomatic up to one year or more. Evidence suggests that patients whose symptoms persist are not simply "neurotic." Rehabilitation efforts should focus on proper evaluation, reassurance, education, support and monitoring of progress.

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.

Long-term survival, prognosis, and life-care planning for 29 patients with chronic locked-in syndrome.

We present a life-table analysis of a cohort of 29 locked-in syndrome (LIS) patients followed for a minimum of five years, and we report on the status of the chronic LIS patient. Twenty-nine LIS patients who remained locked-in for more than one year were identified. Inpatient charts were reviewed for demographic, medical, and functional data. Telephone followup was obtained to examine medical complications after discharge, survival, neurologic recovery, care issues, and permanent disposition. A life-table analysis was performed on survival data. Cerebrovascular disease was the most common cause of LIS. Survival ranged from 2.02 to 18.15 years. Twenty of the 26 patients available for five-year followup survived; hence, five-year survival was 81%. An alternative method of communication and emotional stress for the patient's caregiver was the key issue in patient care. Most patients were cared for in their own homes. Although minimal late neurologic recovery occurs in chronic LIS, survival may, nonetheless, be prolonged with adequate supportive care. Modern computerized technology offers LIS patients the ability to interact with their environment. This information may assist physicians in making ethical and long-term care decisions with the patient rather than for the patient with LIS.

Objective quantification of spastic hypertonia: correlation with clinical findings.

To develop a reliable and objective technique for quantifying spastic hypertonia, ten chronically hemiplegic patients with varying degrees of spasticity were studied on three occasions during several weeks. The modified Ashworth scale, a clinical assessment of extremity tone, was performed before and after each of the following objective tests: (1) torque and EMG measurements during ramp and hold angular displacement about the elbow, (2) pendulum test of the lower extremity, and (3) H/M ratio studies of upper and lower extremities. Subject motor function was also quantified using the Fugl-Meyer motor assessment scale. A regression analysis was performed to determine how successfully each of the objective measures correlated with the clinical yardstick, the modified Ashworth scale. A similar correlation between the objective measures and the Fugl-Meyer motor assessment scale was performed. Temporal reproducibility of a test for a given subject was evaluated by performing an ANOVA of repeated measures for each test over the three study sessions in a given subject. We conclude that (1) both the ramp and hold threshold measurements and pendulum test offer acceptable objective measures of spastic hypertonia since they correlate closely with clinical perception, (2) the Fugl-Meyer motor assessment scale also correlates closely with the severity of spastic tone, and (3) objective measures of spastic hypertonia are often surprisingly reproducible when repeatedly applied to a selected group of chronic hemiplegic patients with long-standing spasticity.

Intraoperative monitoring of an unusual brachial plexus tumor.

This case illustrates the importance of intraoperative monitoring of neuronal function to help separate tumor tissue from neural tissue in a 54-year-old patient with left shoulder pain resulting from a desmoid tumor. Preoperative nerve conduction and electromyographic studies showed a lesion in the lateral cord of the brachial plexus, which was found to be intimately involved with the tumor mass and was splayed into a very thin effaced sheet of neural tissue. Stimulation of the tumor/nerve tissue mass proximal to the lesion was impossible due to the invasion of the brachial plexus by the tumor. The technique that was adapted for this unusual presentation was to stimulate the tumor/nerve tissue mass itself and record compound muscle action potentials distally. With the technique described, a subtotal resection of an aggressive fibromatosis enmeshed in the proximal brachial plexus was possible, and excellent relief of pain symptoms and retention of functional capabilities of the involved extremity were achieved.

Somatosensory-evoked and dermatomal-evoked potentials are not clinically useful in the prognostication of acute spinal cord injury.

This study examined the ability of somatosensory-evoked and dermatomal-evoked potentials to predict motor return after acute spinal cord injury. Fifty-seven of 102 patients who were studied with somatosensory-evoked potentials and dermatomal-evoked potentials were followed for more than 1 year, and their initial electrophysiologic studies were correlated with motor improvement. No patient with a complete spinal cord injury on initial physical evaluation ever developed motor return. An initial examination demonstrating incomplete spinal cord injury heralded a result of walking or better in 56.4% of incomplete patients with spinal cord injury. Both the initial physical examination and evoked potentials were reasonable predictors of further motor improvement. However, evoked potentials added little or no useful prognostic information to the initial physical examination in either complete or incomplete spinal cord injury patient groups.

Research in physical medicine and rehabilitation. XII. Measurement tools with application to brain injury.

There are basic principles and techniques of measurement that are relevant across biomedical disciplines. The purpose of this article is to explain some of the most important of these for medical rehabilitation, to illustrate how to use them to choose assessment instruments and to describe the nature of measurement in medical rehabilitation by examples in brain injury rehabilitation. Reliability is basic to any scientific measure. Validity, the ultimate criterion, is closely associated with the purpose of the measure. Content validity, criterion validity and construct validity are explained. Sensitivity to rehabilitative interventions and significance in patients' real lives (ecological validity) are emphasized. Measures of functional outcomes (disability) may show improvement after rehabilitation even when impairment measures do not. An extensive but selected list of measures of coma, global status, disabilities, communicative and cognitive impairments, and handicaps is presented, and their main uses are illustrated. Examples illustrate how to choose measures to study comprehensive program-level outcomes, to study learning-based interventions and to develop a general purpose database. Although there are many measures of activities of daily living and mobility, little published evidence of reliability and validity could be found even for some well-known scales. Ecologically valid and sensitive outcome measures are especially needed. Studies of the clinical utility of measures were also scarce. Many of these gaps can be spanned by clinical researchers with limited resources. Physical medicine and rehabilitation will benefit from formal studies of the reliabilities and validities of both its old and its new measurement instruments and by increased sophistication in choice of measures.

Magnetoelectric stimulation of human motor cortex: normal values and potential safety issues in spinal cord injury.

Upon magnetoelectric stimulation (MES) of the motor cortex, maximal amplitude and minimal latency of compound muscle action potentials were recorded for four limbs in 20 able-bodied volunteers after ten sequential stimulations. The ratio of maximal cortical to maximal peripheral compound muscle action potential was calculated. Standard statistical parameters were calculated for values from each limb. A paired t-test revealed a statistically significant difference in lower extremity side-to-side amplitude. Regression analysis of patient height vs upper extremity and lower extremity latency demonstrated a strong correlation: r = .720 and r = .601, respectively. A pendulum model demonstrated that a miniscule amount of energy is imparted onto metallic fixation devices by the magnetic coil, but no significant paraspinal activity could be measured in any of five volunteers upon stimulation of the motor cortex. This study has established a normal MES data base that might be useful in evaluating spinal cord injured patients. It has also demonstrated that initial safety concerns about the use of MES in this population are likely unfounded.

Focal dystonia following soft tissue injury: three case reports with long-term outcome.

Three cases of focal dystonia are described which followed upper extremity injuries. Each patient developed a dystonic posturing in that limb; two patients improved when their initial condition was addressed. Various authors have proposed that focal dystonia represents a limited form of generalized dystonia, which is believed to result from a disturbance of striatopallidal-thalamic input to the supplementary motor area (SMA)--a vital executive area for motor control. An alternative hypothesis is offered; that is, a similar dysfunction of the SMA could be the result of altered sensory information from a painful limb disturbing the crucial integration between sensory input and motor performance. The following three examples of such integration are provided: (1) the long loop or transcortical reflex, (2) input of distinctive somatosensory neurons to the SMA, and (3) the projection of proprioceptive and tactile sensory input into peripheral receptive fields of the motor cortex.

Driving safety after brain damage: follow-up of twenty-two patients with matched controls.

Driving after brain damage is a vital issue, considering the large number of patients who suffer from cerebrovascular and traumatic encephalopathy. The ability to operate a motor vehicle is an integral part of independence for most adults and so should be preserved whenever possible. The physician may estimate a patient's ability to drive safely based on his own examination, the evaluation of a neuropsychologist, and a comprehensive driving evaluation--testing, driving simulation, behind-the-wheel observation--with a driving specialist. This study sought to evaluate the ability of brain-damaged individuals to operate a motor vehicle safely at follow-up. These patients had been evaluated (by a physician, a neuropsychologist, and a driving specialist) and were judged able to operate a motor vehicle safely after their cognitive insult. Twenty-two brain-damaged patients who were evaluated at our institution were successfully followed up to five years (mean interval of 2.67 years). Patients were interviewed by telephone. Their driving safely was compared with a control group consisting of a close friend or spouse of each patient. Statistical analysis revealed no difference between patient and control groups in the type of driving, the incidence of speeding tickets, near accidents, and accidents, and the cost of vehicle damage when accidents occurred. The patient group was further divided into those who had, and those who had not experienced driving difficulties so that initial neuropsychologic testing could be compared. No significant differences were noted in any aspect of the neuropsychologic test battery. We conclude that selected brain-damaged patients who have passed a comprehensive driving assessment as outlined were as fit to drive as were their normal matched controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Updates on the diagnosis and management of posttraumatic hydrocephalus.

Posttraumatic hydrocephalus is a vital subject for the practitioner caring for patients with traumatic encephalopathy, as a large number of brain trauma patients develop ventricular enlargement. The managing physician should understand which ventriculomegalic patients are suffering from hydrocephalus, which have cerebral atrophy and which stand a reasonable chance of improvement on surgical placement of a ventricular shunt. This paper highlights this decision process in two patients, and offers the physician a practical overview of posttraumatic hydrocephalus and its management.

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.