Donal Munro Lecture: Functional and neurologic recovery following acute SCI.

Patient management in the current health care environment requires the provider to make reliable and valid clinical decisions regarding patient care, decisions that are cost effective and will lead to optimal functional improvement. Neurologic examination, according to the Standards for Neurological and Functional Classification of Spinal Injury developed by the American Spinal Injury Association, provides every clinician with simple clinical tools that are highly predictive of functional recovery following a spinal cord injury. The ability to predict motor recovery provides a rational basis to help support the provider's recommendation for the patient's goals and care planning, as well as differentiates care that is essential for improving functional outcomes from care that is not.

Motor recovery following spinal cord injury associated with cervical spondylosis: a collaborative study.

A prospective multicenter study was conducted within the National Model Spinal Cord Injury System program to examine neurological deficits and recovery patterns following spinal cord injury (SCI) in individuals with cervical spondylosis and without a spinal fracture. Nineteen patients were evaluated. Sixty-eight percent presented initially with motor incomplete lesions. Of those who presented with motor incomplete injuries at their initial examination, 69 percent had less deficit in the lower than in the upper extremities, indicative of a central cord syndrome. At follow-up, 12 subjects were unable to ambulate, four required assistance and three were able to ambulate independently. On the average, subjects doubled their initial Asia Motor Score (AMS) scores by one year following injury. Residual upper extremity weakness, however, limited the ability to ambulate. Recovery of motor strength in this group is comparable to that of individuals with incomplete tetraplegia in general but the proportion who regain ambulatory function is less.

Effect of surgery on motor recovery following traumatic spinal cord injury.

The influence of spine surgery on motor recovery between 1 month and 1 year was assessed prospectively in a group of 269 patients following traumatic spinal cord injury (SCI) using the classification system originally developed by the American Spinal Injury Association. The Allen classification was used to categorize cervical vertebral pathology and the Denis system was used for injuries to the thoracic and lumbar spine. Gunshot injuries were classified based upon the bullet trajectory and location relative to the spinal canal. Individuals undergoing surgery were divided into various subgroups depending on the type of surgery performed: anterior decompression with or without spine fusion and instrumentation, posterior decompression/laminectomy with or without spine fusion and instrumentation and spine fusion with instrumentation. Motor score recovery between 1 month and 1 year after injury was highly dependent (P < or = 0.001) on the level and completeness of injury averaging 0.7 +/- 2.7 for complete paraplegics, 7.8 +/- 4.8 for complete tetraplegics, 11.8 +/- 8.3, for incomplete paraplegics and 22.2 +/- 10.9 for incomplete tetraplegics. Motor recovery did not significantly differ between patients categorized in various surgical subgroups or between those having surgery and those treated non-operatively. Additionally, although the sample size was small, motor recovery among tetraplegic individuals did not depend on whether unilateral and bilateral facet dislocations were reduced and in patients with incomplete lesions, those with reductions actually had a poorer outcome than those who were left in a dislocated position.

Injury pattern effect on motor recovery after traumatic spinal cord injury.

OBJECTIVE: To determine whether type of fracture or gunshot injury correlated with extent of motor impairment at 1 month and/or with the amount of motor recovery between 1 month and 1 year. DESIGN: Prospective neurological examinations were performed longitudinally after the recommendations of the American Spinal Injury Association (ASIA). Fractures were classified by the Allen system (cervical spine) or the Denis system (thoracic and lumbar spine). Gunshot injuries were classified based on trajectory and bullet location. SETTING: Subjects were examined at a community medical center. PATIENTS: There were 278 patients with traumatic spinal cord injury who were admitted between 1985 and 1990. MAIN OUTCOME MEASURES: The ASIA motor score was the primary outcome measure. RESULTS: There were no significant differences in motor recovery based on type of injury (penetrating vs nonpenetrating), type of fracture, or bullet location. CONCLUSIONS: Injuries severely disruptive of the spinal canal were more likely to result in complete SCI. Flexion-rotation injuries in the thoracic and lumbar spine, bilateral facet dislocations in the cervical spine, and gunshot wounds in which the bullet passed through the canal were more likely to be complete. Incomplete injuries were more common among patients with preexisting cervical spondylosis who had fallen and patients with gunshot wounds in which the bullet did not penetrate the spinal canal. The primary determinant of motor recovery was completeness of injury at 1 month.

Motor recovery following spinal cord injury caused by stab wounds: a multicenter study.

A prospective multicenter study was conducted by centers participating in the National Model Spinal Cord Injury System program to examine neurological deficit and recovery patterns following spinal cord injury (SCI) resulting from stab wounds. Thirty two patients were evaluated. Sixty three percent presented with motor incomplete lesions on initial examination. In addition, four of seven who initially presented with motor complete paraplegia were motor incomplete at follow-up. Furthermore, 50% of those with motor incomplete lesions had asymmetrical motor patterns indicative of a Brown-Séquard Syndrome. Although the percentage of patients sustaining an incomplete SCI injury following a stab injury to the spine is higher than the percentage of incomplete lesions associated with other etiologies, the amount of motor recovery when controlling for level and completeness of injury is no greater than previously reported for other etiologies.

Prediction of ambulatory performance based on motor scores derived from standards of the American Spinal Injury Association.

Assessment of strength using motor scores derived from the standards of the American Spinal Injury Association (ASIA) was compared with assessment using motor scores based on biomechanical aspects of walking in the prediction of ambulatory performance. Measurements of strength, gait performance, and the energy expenditure were performed in 36 spinal cord injured patients. The ASIA scoring system compared favorably with the biomechanical scoring system. The ASIA score strongly correlated with the percent increase in the rate of O2 consumption above normal (p < .0005), O2 cost per meter (p < .0006), peak axial load exerted by the arms on crutches (p < .0001), velocity (p < .0001), and cadence (p < .0001). Patients with lower extremity ASIA scores < or = 20 were limited ambulators with slower average velocities at higher heart rates, greater energy expenditure, and greater peak axial load exerted on assistive devices than patients with lower extremity ASIA scores > or = 30 who were community ambulators. We conclude the ASIA motor score is a simple clinical measure that strongly correlates with walking ability.

Motor and sensory recovery following incomplete tetraplegia.

Fifty individuals with incomplete tetraplegia due to trauma underwent serial prospective examinations to quantify motor and sensory recovery. None of 5 patients who were motor complete with the presence of sacral (S4-S5) sharp/dull touch sensation unilaterally recovered any lower extremity motor function. However, in 8 motor complete subjects having bilateral sacral sharp/dull sensation present, the mean lower extremity motor score increased to 12.1 +/- 7.8 at 1 year. In 3 of the 8 cases, functional (> or = 3/5) recovery was seen in some muscles at 1 year. Though mean upper and lower extremity ASIA Motor Scores increased significantly (p < .001) between 1 month and 1 year for the entire sample, the annualized rate of motor recovery rapidly declined in the first 6 months and then subsequently approached plateau. Eighty-seven percent (20 of 23) of patients having a lower extremity motor score > or = 10 at 1 month were community ambulators using crutches and orthoses at 1 year follow-up.

Motor and sensory recovery following incomplete paraplegia.

Fifty-four individuals admitted for rehabilitation with a diagnosis of incomplete paraplegia due to trauma underwent serial prospective examinations to quantify motor and sensory recovery. Motor and sensory scoring guidelines recommended by the American Spinal Injury Association were used to assess changes. Lower extremity motor scores (LEMS) differed significantly (p < .03) between groups of patients partitioned by category of initial neurologic level of injury (NLI) with the following averages at 1 month after injury: 6.8 +/- 11.3 above T12, 15.0 +/- 8.2 at T12 and 18.3 +/- 11.4 below T12. However, the amount of motor recovery was independent of the NLI with the differences between the NLI groups remaining essentially constant from 1 month to 2 years. While the LEMS increased significantly (p < .001) an average of 11.9 +/- 8.7 points between 1 month and 1 year, the annualized rate of motor recovery rapidly declined in the first 6 months and then subsequently plateaued. All patients having a 1-month LEMS greater than 10 points (28 cases) with hip flexion or knee extension strength > or = 2/5 were able to ambulate in the community with a reciprocal gait pattern using crutches and orthoses at 1-year follow-up.

Recovery following ischemic myelopathy.

Motor and sensory recovery were determined in five patients with ischemic myelopathy associated with traumatic laceration or surgical manipulation of the thoracic aorta. The neurologic level of injury was between T-2 and T-10. All patients had an anterior spinal artery pattern of incomplete spinal cord injury consisting of relatively greater loss of motor function than sensation and preservation of sacral sensation. None of the three patients with zero lower extremity motor function at 30 regained any motor function at 1 year. Two patients with partial motor function 1 month after infarction had further motor recovery at 1 year. One of these two individuals was able to ambulate independently with a reciprocal gait using orthoses.

Motor and sensory recovery following complete tetraplegia.

Sixty-one individuals admitted for rehabilitation with a diagnosis of complete tetraplegia due to traumatic spinal cord injury underwent prospective examinations for motor and sensory recovery. The amount of motor, light touch and sharp/dull (pin prick) sensory recovery was independent of the initial neurologic level of injury between C4 and C8. In the interval between one month and one year following injury, the American Spinal Injury Association Motor Score increased an average of 8.6 +/- 4.7. However, the rate of motor recovery rapidly declined in the first six months and then approached plateau. Ninety-seven percent of muscles with Grade 1/5 ("Trace") or 2/5 ("Poor") strength one month after injury recovered to > or = 3/5 ("Fair") strength by the time of first annual follow-up. Muscles with 0/5 strength one month after injury and located one neurological level below the most caudal level having motor function regained > or = 3/5 strength in only 27 percent of cases at one year follow-up and at two levels below in only 1% of cases.

Gait performance after spinal cord injury.

Physiologic and mechanical gait parameters were measured in 36 spinal cord injury (SCI) patients to quantify gait impairment. Average age of the 30 males and six females was 29.0 +/- 10.1 years. Patients were tested at the time of discharge from initial rehabilitation (mean, 0.5 +/- 0.7 years postinjury). Compared with able-bodied subjects tested in the same laboratory, the SCI patients walked 52% slower (41.1 m/minute versus 79.8 m/minute, respectively), the rate of oxygen consumption was 23% higher (14.9 ml/kg.minute versus 12.1 ml/kg.minute), and the oxygen cost per meter was 240% higher (0.52 ml/kg.m versus 0.15 ml/kg.m). Peak axial load on upper extremity walking aids averaged 21.7% of body weight, and the ambulatory motor index (AMI), derived from lower limb strength grades, was 52% of normal strength. The AMI closely correlated with the peak axial load and the percent increase in the oxygen rate above normal. Differences in the AMI among patients accounted for changes in physiologic parameters; therefore, the AMI can be used as a clinical predictor of functional mobility. Annual follow-up studies were performed on ten of the 36 patients. Compared with the initial testing, these patients walked faster (59.9 m/minute versus 40.4 m/minute), more efficiently (0.26 ml/kg.m versus 0.40 ml/kg.m), with slower heart rates (115 beats/minute versus 133 beats/minute), and the peak axial load was less (18% of body weight versus 26% of body weight).

Recovery following complete paraplegia.

Motor and sensory recovery were quantified by serial examinations prospectively performed on 148 persons with paraplegia. Of the 142 patients who remained complete injuries at follow-up, none with an initial neurologic level of injury (NLI) above T9 regained any lower extremity motor function at follow-up. Thirty-eight percent of patients with an initial NLI at or below T9 had some return of lower extremity motor function, primarily in the hip flexors and knee initial NLI at or below T9 had some return of lower extremity motor function, primarily in the hip flexors and knee extensors. Twenty percent of the patients with an initial NLI at or below T12 regained sufficient hip flexor and knee extensor strength to reciprocally ambulate using conventional orthoses and crutches. Unlike motor function, recovery of light touch and sharp-dull discrimination was independent of the initial NLI. Six (4%) of the 148 patients demonstrated "late" conversion (more than 4 months after injury) from complete to incomplete spinal cord injury (SCI) status. Two of the 6 patients with an initial NLI at T12 and subsequent annual NLI at L1 and L2 reciprocally ambulated, and three of the 6 patients regained voluntary bladder/bowel control.

Definition of complete spinal cord injury.

Prospective serial neurological examinations were performed on 445 consecutive traumatic spinal cord injury (SCI) patients admitted for rehabilitation on an average of 22.8 +/- 15.6 days after injury. Patients were categorized by both the ASIA and Sacral Sparing (SS) definitions of complete SCI, in order to compare the definitions in terms of consistency and prognostic ability. Recovery during follow-up was determined by sensory scores for light touch, sharp/dull discrimination, proprioception, and the ASIA Motor Index Score. Change in complete status was unidirectional using the SS definition and bidirectional using the ASIA definition. Twelve patients with SS complete injuries on initial examination converted to SS incomplete injuries at follow-up. No patients converted from SS incomplete to SS complete injury. Twenty three patients with ASIA complete injuries upon admission converted to ASIA incomplete status and 6 converted from ASIA incomplete status on admission to ASIA complete status at follow-up. For quadriplegics, the average motor recovery for patients changing complete status according to the ASIA definition was 11.7 +/- 10.3, which was significantly less (p less than .05) than the average recovery using the SS definition (group 1), 17.9 +/- 9.3. For paraplegics, the average motor recovery using the ASIA definition, 8.3 +/- 6.7, did not differ significantly from the value using the SS definition, 6.8 +/- 4.0.

Profiles of spinal cord injury and recovery after gunshot injury.

Prospective motor and sensory examinations were conducted on 135 patients with neurologic deficits caused by spinal cord injuries resulting from gunshot wounds. Annual follow-up motor and sensory examinations were conducted for 67 patients. The neurologic data (motor and sensory neurologic levels of injury, zone of injury, and completeness of lesion) were assessed in terms of the vertebral level of injury, region of injury, bullet caliber, direction of bullet entry, and whether the bullet penetrated the spinal canal, completely traversed the spinal canal, or entered and remained lodged in the spinal canal. Seventy-seven of the patients sustained complete lesions and 58 sustained incomplete lesions. Anatomically, 19.3% of the injuries were in the cervical region, 51.8% in the thoracic, and 28.9% in the thoracolumbar. In 93 cases, the neurologic level was at least one level higher than vertebral level of injury. Although twice as many individuals were shot from the back as from the front and from the left as from the right, the point of bullet entry did not appear to be related to the severity of the injury. At the annual follow-up examinations, 66.7% of the patients with complete lesions and 64.0% of the patients with incomplete lesions had no improvement in the neurologic level of injury. Nevertheless, there was a significant (p less than 0.0001) improvement in the American Spinal Injury Association motor index scores one year after injury.

Changes in ambulation parameters in spinal cord injury individuals following rehabilitation.

The energy cost and gait parameters of 10 spinal cord injury patients (mean age = 21.7 +/- 2.3 years) were measured at discharge from initial rehabilitation and at 1 year follow-up. At follow-up testing patients walked faster (59.5 m/minute vs 40.4 m/minutes; p less than 0.001), more efficiently (0.26 ml O2/kg.m vs 0.40 ml O2/kg.m; p less than 0.05) had slower heart rates (115 beats/minute vs 133 beats/minute; p less than 0.01), and required decreased axial load on upper extremity assistive devices (18% body weight vs 26% body weight; p less than 0.03). At follow-up testing, those patients with remaining weakness in the lower limbs had greater conditioning effects (increased rate of oxygen consumption and oxygen pulse) than those patients with relatively stronger limbs. These findings indicate that clinicians can expect significant improvements in functional ambulation performance in the first year following initial rehabilitation due to improved strength and conditioning.

Determinants of gait performance following spinal cord injury.

Measurement of lower extremity muscle strength and the energy expenditure during walking was taken in 36 spinal cord injury patients to assess functional mobility. Patients were categorized according to the type of orthotic prescription (knee-ankle-foot orthosis [KAFO] or ankle-foot orthosis [AFO]) or upper extremity assistive device (cane, crutches, or walker) used during gait. The rates of O2 consumption per minute, O2 cost per meter, heart rate, respiratory quotient, velocity, cadence, and peak axial load exerted by the arms on upper extremity assistive devices were measured. The Ambulatory Motor Index (AMI), derived from the manual muscle grades of both lower limbs, was used as the indicator of the degree of paralysis. The AMI was strongly correlated with the percentage increase in the rate of O2 consumption above normal (p less than .0001), O2 cost per meter (p less than .0001), peak axial load (p less than .0001), velocity (p less than .0001), and cadence (p less than .0001). Differences in these parameters among patient groups categorized according to the type of orthotic prescription (no KAFO, one KAFO, two KAFOs) or upper extremity assistive device (no device, cane or one crutch, two crutches, or walker) were attributable to differences in the AMI. The AMI, therefore, could be used as a reliable clinical indicator of functional mobility after spinal cord injury.