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Biomedical subjects

J F Ditunno

Publications and source records attributed to J F Ditunno.

At least 19 recordsLinked to original sources

Incomplete spinal cord injury: neuronal mechanisms of motor recovery and hyperreflexia.

OBJECTIVE: To understand neuronal mechanisms of motor recovery and hyperreflexia after incomplete spinal cord injury (SCI), and their role in rehabilitation. DESIGN: Reviewed and compared clinical, neurophysiologic, and neuropathologic data from human SCI patients with behavioral, neurophysiologic, and neuroanatomic data from animals to postulate underlying neuronal mechanisms. OUTCOME: A postulation that two neuronal mechanisms-receptor up-regulation and synapse growth-act sequentially, to explain the gradual appearance of motor recovery after incomplete SCI. These same mechanisms may also act in spinal reflex pathways to mediate hyperreflexia caudal to SCI. RESULTS: After incomplete SCI, walking ability and hyperreflexia often develop. Initially, cord neurons are hyperpolarized and less excitable because of loss of normal descending facilitation; this is spinal shock. Then, gradually, voluntary movement recovers and hyperreflexia develops. Early (hours to days), these changes develop simultaneously, suggesting a common postsynaptic mechanism-likely, an increase in postsynaptic receptor excitability, possibly receptor up-regulation. Late (weeks to months), recovery and reflex changes occur at a slow rate, are no longer simultaneous, and are long-lasting, which suggests a presynaptic mechanism, such as local synapse growth in spared descending pathways and in reflex pathways. This presumed synapse growth is seemingly enhanced by active use of the growing pathway. Also, developing hyperreflexia appears to limit motor recovery. CONCLUSIONS: These observations suggest that rehabilitation for incomplete SCI should (1) increase activity in spared descending motor pathways, (2) initially use reflex facilitation or central nervous system stimulants to assist spared descending inputs in depolarizing cord neurons, and (3) later minimize reflex input, when spared descending inputs can depolarize cord neurons without reflex facilitation. Better understanding of neuronal mechanisms that underlie motor recovery after incomplete SCI promises better outcomes from rehabilitation.

Animals

Cost of walking and locomotor impairment.

The aim of the present study was to evaluate the importance and the necessity of metabolic measurements to quantify locomotor impairment in a clinical context. Oxygen consumption, heart rate, pulmonary ventilation and walking speed were measured during locomotion in 14 normal subjects, used as a control group, and 82 patients with different pathologies [hemiparetic, paraparetic, tetraparetic, orthopaedic and paraplegic patients, who walked using a reciprocating gait orthosis (RGO)]. The subjects were characterized on the basis of a cumulative impairment score (CIS), based on clinical scales commonly used to evaluate impairment and disability in locomotion. Appropriate indices of energy, cardiac and ventilatory costs expressed per metre walked, globally called physiological costs, were obtained. It resulted that the most comfortable speed (MCS) of normal subjects was significantly higher than that of each group of patients. Normal subjects' physiological costs were found to be significantly lower than those of patients who needed either a device or the help of a person to walk. All measured parameters correlated significantly with each other. The MCS was found to be the most correlated parameter with the CIS (r = 0.8), and therefore it must be considered the best single measurement, if only one is to be used. Measurements more precise than MCS, such as the physiological costs, may be necessary in clinical trials.

Adult

Ambulation training of neurological patients on the treadmill with a new Walking Assistance and Rehabilitation Device (WARD).

STUDY DESIGN: Patients with neurological walking impairment were rehabilitated with a new system, consisting of an apparatus to constantly relieve the body weight and a treadmill: The Walking Assistance and Rehabilitation Device (WARD). Patients were evaluated before and after rehabilitation with clinical scales and physiological measurements. OBJECTIVES: To evaluate the effectiveness of the WARD in improving walking capability in these patients. SETTING: The study was carried out in a clinical environment (IRCCS S. Lucia, Rehabilitation Hospital, Rome, Italy). METHODS: Seven patients (six with spinal cord injuries, one with brain injury) underwent a 1 - 2 month training period with the WARD. During the WARD training the body weight constant unloading (BWCU) applied to the patient through the WARD was regularly evaluated. Oxygen consumption, carbon dioxide production and heart rate were measured in order to obtain energy and cardiac costs of walking. These measurements were carried out while walking with the WARD at an appropriate treadmill speed (ATS) and in the open field at the most comfortable speed (MCS). All measurements, in addition to clinical scores related to the walking capability, were carried out at the beginning of the WARD training period (BWT) and at the end (EWT). At the EWT the patients were tested walking with the WARD observing the same BWT conditions (same ATS and BWCU), referred to as beginning conditions second measurements (BCSM). The relationships between physiological costs and ATS were described through second order polynomial regression curves and studied. RESULTS: Comparing the data obtained at the BWT and EWT, the following results were found significantly different: (1) Clinical scores improved; (2) All patients increased their ATS; (3) The BWCU was reduced; (4) The Walking Energy Cost (WEC) and the Walking Cardiac Cost (WCC) measured when walking with the WARD at the ATS improved in all patients; and (5) The WEC and WCC measured in the open field improved in all patients. The WEC vs ATS curve found at the EWT in the BCSM was found significantly different from the BWT curve, demonstrating a major improvement due to the WARD training. CONCLUSION: Despite some limitations due to sample size and functional ambulation scale, this study has demonstrated that the WARD training is effective in improving the walking capability and efficiency of the patients.

Adult

A test of the 1992 International Standards for Neurological and Functional Classification of Spinal Cord Injury.

This study was designed to test the 1992 International Standards for Neurological and Functional Classification of Spinal Cord Injury. One hundred and six professionals in the field of spinal cord injury attending an instructional course at the 1994 ASIA Meeting participated in the test. Participants completed a pretest and posttest in which they classified two patients who had a spinal cord injury (one with complete tetraplegia and one with incomplete paraplegia) by sensory and motor levels, zone of partial preservation (ZPP), ASIA Impairment Scale and completeness of injury. Between tests, three members of the ASIA Standards Executive Committee gave presentations on the neurological assessment, scoring, scaling and classification of spinal cord injury and a video of the actual examinations of the two cases was viewed. Percent 'correct' (as defined by the ASIA Standards Committee) was calculated for sensory and motor levels, ZPP, ASIA Impairment and completeness. Overall, the analyses showed that participants had very little difficulty in correctly classifying the patient with complete tetraplegia. Pretests scores ranged from 72% (left motor level) to 96% (complete injury), posttest scores from 73% (left motor level) to 100% correct (complete injury). For the patient with incomplete paraplegia (Case 2), scores were considerably lower. Pretest scores ranged from 16% (right motor level) to 95% correct (incomplete injury); posttest scores from 21% (right motor level) to 97% correct (incomplete injury). The results showed that further revisions of the 1992 Standards and more training is needed to ensure accurate classification of spinal cord injury.

Chi-Square Distribution

Recovery of ambulation in motor-incomplete tetraplegia.

OBJECTIVE: To determine the effect of age and initial neurologic status on recovery of ambulation in patients with motor-incomplete tetraplegia. STUDY DESIGN: Inception cohort study. SETTING: Urban, tertiary care hospital with Regional Spinal Cord Injury Center. PATIENTS: One hundred five patients with American Spinal Injury Association (ASIA) C or D tetraplegia at admission or within 72 hours of injury. MAIN OUTCOME MEASURE: Ambulatory status at time of discharge from inpatient rehabilitation. RESULTS: Ninety-one percent (30/33) of ASIA C patients younger than 50 years of age became ambulatory by discharge, versus 42% (13/31) ASIA C patients age 50 or older (p < .0001). All (41/41) patients initially classified as ASIA D became ambulatory by discharge. CONCLUSION: For patients with ASIA D tetraplegia, prognosis for recovery of independent ambulation is excellent. For patients with ASIA C tetraplegia, recovery of ambulation is significantly less likely if age is 50 years or older.

Age Factors

Neurological issues.

The case histories of two patients who had had a spinal cord injury (SCI) were selected by the senior author and sent to four experts in the field of SCI. Based on the 1992 American Spinal Injury Association (ASIA) and International Medical Society of Paraplegia (IMSOP) standards, the four participants plus the senior author recorded the motor and sensory scores, the ASIA impairment scale (AIS), the neurological level (NL) and the zone of partial preservation (ZPP). Several minor scoring errors occurred among the participants, especially with motor scores when key muscles could not be tested due to pain, or external immobilization devices. Difficulties with interpretation occurred with the motor levels and the ZPP for the patient with a complete injury. This exercise points to the need for all examiners of SCI patients to thoroughly familiarize themselves with the standards and to use the motor and sensory scores to arrive at a NL and ZPP. They also indicate a need to revise the standards to clarify the determination of sensory levels and how to score muscles whose strength is inhibited by pain.

Adult

Functional outcomes in spinal cord injury (SCI): quality care versus cost containment.

Our ability to assess functional outcomes in SCI has recently been improved by agreement with standards for neurological and functional classification of spinal cord injury. This widely accepted classification should allow uniform measures of impairment and disability and serve as the gold standard for functional outcomes. Measures of impairment allow comparison of more than 15,000 subjects with Frankel grades and severity of paralysis reported to the National Database and comparison of the disability measures, the Functional Independence Measure (FIM) in over 2,500 cases which correlates with level and severity of paralysis. These standards are currently in use in several multicenter drug trials and should yield information regarding the effects of pharmacological interventions on impairment/function in the next several years. Studies of the effects of surgery, exercise and health care systems are beginning to emerge. Some investigators suggest social roles, perceived improvement and quality of life scales will be powerful tools in shaping health care reform. More recently, cost efficiency has been added to traditional studies of safety, efficacy and effectiveness. Quality Adjusted Life Years (QALY) and value-added care are new terms introduced into health care. Cost containment proponents are cautioned that improved value and added quality care may result in greater cost efficiency, but not reduced costs. Spinal cord injury care in the future must be cost efficient and, in addition, improve the health status and satisfy the consumer.

Cost Control

Prognostic significance of the delayed plantar reflex following spinal cord injury.

The delayed plantar reflex (DPR) is a pathologic flexor variant which requires unusually strong stimulation of the sole of the foot and is characterized by a prolonged interval between the stimulus and the response, slow and protracted plantarflexion of the great toe and/or other toes and slow return to the neutral position. The purpose of this study was to evaluate prospectively the functional outcome of spinal cord injury (SCI) patients based on the presence or absence of a DPR immediately following injury. Thirty-six subjects were evaluated within one week of injury. A complete neurological evaluation following American Spinal Injury Association (ASIA) standards was performed and the presence or absence of a DPR was noted on admission. Ambulation status and ASIA Impairment Scales were recorded at discharge from the rehabilitation unit and the data were analyzed by the Chi-square method with Yates' correction for continuity. The data demonstrated a high correlation of the DPR with motor complete injuries (p < 0.01) and a poor prognosis for recovery of ambulation (p < 0.01). Clinicians should recognize this abnormal reflex, which may be used in conjunction with a complete neurological examination, to help prognosticate future function in the acute SCI patient.

Adolescent

Neurological assessment in spinal cord injury.

Precise and reliable neurologic assessment is a necessary tool for determining the extent and pattern of recovery after SCI. Recently agreed upon international standards establish a uniform neurologic classification to measure clinical outcomes. They are currently in use in three multicenter studies in more than 40 SCI centers in the United States. The Model System SCI centers report the use of these measures, such as impairment grades and neurologic levels, in almost 15,000 cases over the past 20 years and, more recently, motor scores in 3,500 patients. The NASCIS II multicenter trial on methylprednisolone used motor and sensory scores as endpoints in close to 500 patients, but have incorporated the international standards, which include a disability measure, in NASCIS III. The study of ganglioside effectiveness also is using these measures in many patients. In more focused studies, neurologic assessment soon after injury can predict walking in motor complete injuries based on pin prick sensation, and in motor incomplete injuries based on impairment grade and age. Eventual upper extremity function can be estimated based on the motor examination within 72 hours of injury. Both the motor score and motor level are more reliable in predicting upper extremity function than the single sensory level. This presumably reflects the greater importance of motor recovery on functional outcome. The proximal muscles of the lower extremities caudal to the lesion site recover before distal muscles, and this may be mediated by axons descending in the ventral tracts, which control primarily proximal rather than distal muscles. These axons may be preferentially spared and/or have greater capacity to compensate than those present in the lateral columns. In conclusion, standard neurologic assessment in SCI is extremely valuable in monitoring recovery in order to prognosticate functional outcome, evaluate effectiveness of drug interventions, and provide valuable clues to possible underlying mechanisms of recovery. The elucidation of these mechanisms will aid in the refinement of current treatments and development of new strategies to enhance neurologic recovery and functional outcome.

Humans

Spinal cord injury and bladder recovery.

OBJECTIVE: To investigate whether spinothalamic tract preservation and posterior column sparing are predictors of neurogenic recovery of bladder function after spinal cord injury (SCI). DESIGNS AND PARTICIPANTS: In a retrospective review, the initial perianal pinprick sensation (S4.5 dermatomes) and position sense of the great toes were examined and correlated with bladder function at 1 year after SCI in 19 consecutive spinal cord injured patients (age 18 to 68 years), Frankel A-D, with spinal injury (level C-4-T-12). All patients were admitted to the Regional Spinal Cord Injury Center of Delaware Valley (RSCIDDV) within 72 hours of injury between July 1990 and June 1991 and were available for a 1-year follow-up evaluation. MAIN OUTCOME MEASURES: The correlation of initial perianal pinprick and great toe position sensation with bladder management approximately 1 year after SCI. RESULTS: During the initial 72 hours, 10 of the 19 patients had positive perianal pinprick sensation and 9 did not feel the pin. Eight patients had positive great toe position sense, and 11 had no proprioception. At the 1-year follow-up visit, 7 of the 10 patients with initial preserved perianal pinprick were voiding volitionally, whereas none of the 9 patients who did not have pinprick voided volitionally at 1-year after SCI. Six of the 8 with initial preserved great toe position sense were voiding volitionally at 1 year, but only 1 of the original 11 without initial toe position sense was voiding volitionally. CONCLUSIONS: Both perianal pinprick sensation and toe position sense are sensitive in predicting return of bladder function. Although both tests have positive predictive value, their negative predictive values are much more noteworthy. A patient without initial position sense of the great toes will likely not regain volitional voiding, whereas a patient without initial perianal pinprick sensation will definitely not regain volitional voiding.

Adolescent

Strength post-spinal cord injury: myometer vs manual muscle test.

This study was designed to compare changes in strength after spinal cord injury (SCI) with the use of a hand held myometer to the manual muscle test (MMT). Eighty-eight C4-C8 Frankel A-D tetraplegic subjects were tested at various times up to 2 years post-SCI. Elbow flexor strength on successive examinations were grouped according to their early and later MMT scores (3.5 with no change in MMT. 3.5 to 4.0, and 3.5 to 4.5; 4.0 with no change in MMT, 4.0 to 4.5, and 4.0 to 5.0; 4.5 with no change in MMT, and 4.5 to 5.0). For each group, later myometric measurements (MYO) were expressed as percents of their earlier MYO and were analyzed using paired Student t-tests. Later MYO were 116, 205, 232% (P > 0.05, P < 0.002, P < 0.05) of their earlier MYO for groups 3.5 with no change in the MMT, 3.5 to 4.0, and 3.5 to 4.5 respectively. Later MYO were 140, 139, 191% (P < 0.05, P < 0.02, P < 0.0001) of their earlier MYO for groups 4.0 with no change in MMT, 4.0 to 4.5, and 4.0 to 5.0 respectively. Later MYO were 127 and 126% (P < 0.01, P < 0.02) of their earlier MYO for groups 4.5 with no change in MMT and 4.5 to 5.0 respectively. In conclusion the hand held myometer detected changes in muscle strength not detected by the MMT.

Adolescent

Esophageal sensation in spinal cord-injured patients: balloon distension and cerebral evoked potential recording.

We sought to determine the esophageal sensory function in patients with a C6 or C7 spinal cord injury. A balloon was repetitively distended 10 cm above the lower esophageal sphincter in five patients and nine normal control subjects. Sensation was reported on a scale from 0 to 2 with progressive distension to pain threshold (level 2). Cortical responses were recorded from midline scalp electrodes. Blinded determinations of quality and reproducibility of the potentials were performed. All subjects experienced sensation with esophageal balloon distension. Volumes to sensation showed a trend toward a higher sensory threshold in patients but were significant only for first sensation, not pain. In all subjects, a triphasic evoked potential response consisting of a negative-positive-negative complex was noted with distension but not with sham distension. Characteristics (amplitude, latency, reproducibility, and quality) of the evoked potentials were not different in patient and control groups. These data suggest sensory pathways from the distal esophagus are intact in patients with a C6 or C7 spinal cord injury.

Adult

Future ambulation prognosis as predicted by somatosensory evoked potentials in motor complete and incomplete quadriplegia.

OBJECTIVE: The purpose of this prospective study was to determine the efficacy of tibial somatosensory evoked potentials (SEPs) in predicting ambulation in tetraplegic individuals. DESIGN: This was a prospective study of a cohort of cervical spinal cord-injured patients who had SEPs recorded within 72 hours to 2 weeks post-SCI and whose ambulation outcome was followed up to 2 years post-SCI. SETTING: Regional Spinal Cord Injury (SCI) Center. PATIENTS: All male and female subjects admitted to the center from 1988 to 1991 between the ages of 15 and 60 years who demonstrated C4 through T1 complete and incomplete acute SCIs were asked to participate in this study. MEASUREMENTS: The tibial nerve cortical SEPs were graded as either present or absent. The waveforms were also graded as less than 0.5 microV or > or = 0.5 microV. Quadriceps strength plus touch and pin sensation were tested within 72 hours to 2 weeks post-SCI. Ambulation was rated as absent, exercise, household, or community. The ambulatory and clinical status were assessed monthly for 3 months, and then at 6, 12, 18, and 24 months post-SCI. Statistical analysis using the two-tailed Fisher's exact test was performed relating the initial clinical and SEP data to ambulation outcome up to 24 months post-SCI. RESULTS: All 13 subjects with a right and/or left quadriceps manual muscle test (MMT) greater than 0/5 became ambulatory. Of the 9 subjects with an initial bilateral quadriceps MMT = 0/5, only 1 recovered enough lower limb function to ambulate (p = .0001). One of the 7 subjects with absent touch sensation in the lower limbs became ambulatory, whereas 14 of the 15 subjects with touch sensation present became ambulatory (p = .002). All 7 subjects with absent pin sensation in the lower limbs were nonambulatory, and 14 of 15 subjects with pin sensation present became ambulatory (p < .0001). Of the 9 subjects with bilaterally absent cortical SEP waveforms, 2 became ambulatory. Twelve of the 13 subjects with a cortical SEP wave present became ambulatory (p = .0015). Of the 10 subjects with a cortical SEP wave amplitude less than 0.5 microV, only two became ambulatory, whereas all 12 subjects with an amplitude > or = 0.5 microV became ambulatory (p = .00014). In no subject did the SEP predict future ambulation where the clinical examination did not also predict recovery of ambulation. CONCLUSION: Both the early postinjury clinical evaluation and the SEP predicted ambulation outcome to a significant degree, but the SEP offered no additional prognostic accuracy over that provided by the clinical examination.

Adolescent

Superiority of motor level over single neurological level in categorizing tetraplegia.

The purpose of this paper is to demonstrate the superiority of the American Spinal Injury Association motor level (ML) and upper extremity motor score (UEMS) to the neurological level (NL) in determining self care function in motor complete tetraplegia. Fifty subjects with traumatic motor complete tetraplegia, NL C4-C8, were evaluated at admission and 12 months post injury. At both time periods NL, ML, and UEMS were determined. At 12 months, reported ability to perform six feeding activities of the Quadriplegia Index of Function (QIF) were documented. Spearman correlations of the NL, BML, WML, UEMS, and feeding QIF scores were conducted, and results were compared with t tests for significant differences. Both the best and worst ML were more highly correlated to the UEMS than was the NL (0.96 and 0.96 vs 0.66, P < 0.001). The best and worst ML were more highly correlated to the QIF feeding score than was the NL (0.74 and 0.72 vs 0.56, P < 0.05). The UEMS had the highest correlation to the QIF feeding score, 0.78. These results suggest that the NL is an imprecise descriptor of the impairment in SCI, and is therefore a poor predictor of the resultant disability. The ML and the UEMS better reflect the severity of impairment and disability after motor complete tetraplegia.

Activities of Daily Living

Wrist strength measured by myometry as an indicator of functional independence.

The purpose of this study was to show that independence of self care activities of motor complete quadriplegic patients related better to the force of contraction of the wrist extensor (WE) muscles measured by a hand held myometer than to the manual muscle test (MMT) for grades 3 to 5. The patients (n = 24), identified by having unilaterally or bilaterally functional WE muscle (MMT > or = 3/5) with bilateral elbow extensor (EE) muscles < 3/5, were evaluated at 2 to 6 months after injury for four feeding activities utilizing the Quadriplegia Index of Function (QIF). We found 54% were independent drinking from a cup, 58% using a spoon or fork, 13% cutting food, and 23% pouring liquids. Comparisons were made between right, left, and bilateral mean myometry scores and median MMT scores for each of the QIF activities. The independent group of patients had myometry scores 54 to 140% greater (p < 0.05) than those patients dependent in the self care activity except when the right or left WE myometric score was analyzed for cutting food (p = 0.1). MMT comparisons showed no significant median score differences in any activity performed. There were no patients with only one WE muscle > or = 3/5 (n = 9) who were able to cut food or pour liquids independently. In conclusion, myometry appeared to be a better indicator than the MMT for some self care activities evaluated utilizing the Quadriplegia Index of Function.

Activities of Daily Living