Evaluation of the lower motor neuron integrity of upper extremity muscles in high level spinal cord injury

PURPOSE

To evaluate the lower motor neuron (LMN) integrity of upper extremity muscles of persons with high tetraplegia (C1-C4) in order to determine muscles available for stimulation.

METHODS

Fourteen subjects (23 arms) were evaluated for LMN integrity. Muscles that elicited a functional response (grade 3 or better) to surface electrical stimulation were considered to have intact LMN and good candidates for FES. Strength-duration (S-D) curves were generated on muscles that showed weak (less than grade 3) or no response to surface stimulation. Muscles were considered denervated if S-D curves were discontinuous or depicted steep, increasing amplitude for pulse durations greater than 1 m.

RESULTS

Muscles for grasp and release had intact LMN in 19 of 23 (83%) arms. The wrist extensors and flexors and pronator were excitable in 17 (74%), 20 (87%) and 19 (83%) arms, respectively. The supinator demonstrated LMN lesion in 80% of the arms. Over 90% of the biceps muscles were unresponsive to electrical stimulation and 85% and 87% of the deltoid and supraspinatus muscles, respectively, were not electrically excitable. The latissimus dorsi and triceps muscles were typically innervated (78% and 91%, respectively) and slightly more than half (52%) of the pectoralis major muscles were excitable.

CONCLUSION

These data suggest that application of FES in high tetraplegia for hand and arm function would require augmentation because of the inability to stimulate the elbow flexors, deltoid and rotator cuff muscles. These data also show that several paralyzed proximal muscles with intact LMN that have been historically transferred to address shoulder paralysis in other patient populations are available for transfer and stimulation in the population with high level spinal injuries.

A prospective evaluation of upper extremity tendon transfers in children with cervical spinal cord injury

Three children (five hands) between 6 and 11 years of age with cervical level spinal cord injuries underwent tendon transfers to restore voluntary lateral pinch. Repeated measures of pinch force and the Grasp and Release Test (GRT) were obtained before surgery and at regular intervals after tendon transfers. The Functional Independence Measure (FIM) was administered before surgery and at 12 months after surgery. Responses to open-ended questions were used to supplement the FIM data at 1 year after surgery. Before surgery, no measurable force was obtained in any hand; after tendon transfers, pinch and finger flexion forces increased throughout the follow-up period. On the GRT, manipulation of the heavy objects was possible only after tendon transfers. Improvements were realized in feeding, grooming, bladder management, play, and school tasks. Each child requested surgery to restore pinch in the nondominant hand. Two hands required tenolysis procedures. Despite capsulotomies and aggressive therapy, three hands continued to have range limitations at the metacarpophalangeal joints.

A study of shoulder motions as a control source for adolescents with C4 level SCI

This study quantitatively examined and compared the shoulder motions of C4 level spinal cord injury (SCI), C5 level SCI, and able-bodied persons as a command source. The study was motivated by both the success of shoulder control in functional electrical stimulation (FES) systems designed for C5 level SCI people and the lack of quantitative information on the shoulder motion of persons with C4 level SCI. A dual-axis transducer was used to monitor the elevation/depression and protraction/retraction angles of each subject's shoulder while they performed three experimental sections which examined: the range of active shoulder motion; the ability to move incrementally to discrete positions with the aid of visual feedback; and the ability to hold discrete shoulder positions for an extended period without visual feedback. Results indicated that each group had the largest average shoulder displacements (abled = 23 degrees +/- 4 degrees, C5's = 14 degrees +/- 3 degrees, and C4's = 9 degrees +/- 3 degrees) while attempting to elevate and that on average the C4 group had the smallest range of active shoulder motion. No statistically significant differences between the groups were found in either the accuracy or stability of reaching discrete positions with the aid of visual feedback or in the accuracy of holding discrete shoulder positions for an extended period without visual feedback. The results suggest that within their limited range of motion the individuals with C4 level SCI retained shoulder control sufficient for use as an neuroprosthetic command interface.

Self-reported use of an implanted FES hand system by adolescents with tetraplegia

The Freehand System, an eight-channel functional electrical stimulation (FES) system, was implanted in five adolescents with C-5 or C-6 tetraplegia to provide stimulated lateral pinch and palmar grasp. Following completion of inpatient training on how to use the Freehand System for predefined and self-selected activities of daily living (ADL), the adolescents were discharged to use their Freehand systems at home and school. A telephone survey was administered on a weekly basis to obtain information on the type of ADL performed with the Freehand System, reasons for not using the Freehand System, and perceived barriers and motivators to FES use. Twenty surveys were obtained on each adolescent, resulting in a total of 100 surveys. The most common type of activity performed with the Freehand System was self-care, which included tasks such as eating, grooming, and brushing teeth. The Freehand System was also used for productivity activities defined as writing, socialization, and manipulation of school and household objects. Motivators to Freehand System use included perceived need and importance to perform an ADL in an independent fashion, physical ease of using the Freehand System, and availability of social supports that facilitated Freehand System use. While there were several reported barriers to Freehand System use, incompatibility with multiple transfers to and from the wheelchair and lack of physical assistance during morning care to don the system were perceived as two of the more common reasons for nonuse.

Magnetic resonance imaging data in the evaluation of effects of functional electrical stimulation on knee joints of adolescents with spinal cord injury

Diagnostic imaging, consisting of roentgenograms and magnetic resonance images (MRIs), was performed as part of an evaluation of the effects of a functional electrical stimulation (FES) program on the knee joints of 29 adolescents with spinal cord injuries following implantation of fine-wire intramuscular electrodes in their lower extremity muscles. The subjects underwent a regimen consisting of stimulated exercise, standing and/or walking. The effects of FES on knee joints were prospectively studied by reviewing diagnostic imaging data. Evaluation of MRIs and plain radiographs showed no evidence of knee joint pathology secondary to FES exercise or weight bearing. In fact, based on follow-up of MRI scan, many of the joints improved following participation in the program. The MRI data supported the clinical examination of the knee joints of these children. Clinical examination appears adequate for screening for potential knee joint problems.

Implanted functional electrical stimulation hand system in adolescents with spinal injuries: an evaluation

OBJECTIVE

To study the utility and functional benefits of an implanted functional electrical stimulation (FES) system for hand grasp and release in adolescents with tetraplegia secondary to spinal cord injuries.

DESIGN

Intervention study with before-after trial measurement with each subject as his or her own control.

SETTING

Nonprofit pediatric orthopedic rehabilitation facility specializing in spinal cord injury.

PARTICIPANTS

A convenience sample of five adolescents between 16 and 18 years of age with C5 or C6 level tetraplegia at least 1 year after traumatic spinal cord injury. Key muscles for palmar and lateral grasp and release were excitable by electrical stimulation.

INTERVENTIONS

A multichannel stimulator/receiver and eight electrodes were surgically implanted to provide stimulated palmar and lateral grasp and release. In conjunction with implantation of the FES hand system, surgical reconstruction in the form of tendon transfers, tendon lengthenings and releases, and joint arthrodeses was performed to augment stimulated hand function. Rehabilitation of the tendon transfers and training in the use of the FES hand system were provided.

MAIN OUTCOME MEASURES

Measurements of pinch and grasp force, the Grasp and Release Test (GRT), and an assessment of six activities of daily living (ADL) were administered before implantation of the FES hand system and at regular follow-up intervals. Results of the stimulated response of individual muscles and surgical reconstruction were evaluated using standard and stimulated muscle testing techniques and standard assessment of joint range of motion. All subjects completed followup testing.

RESULTS

Lateral and palmar forces were significantly greater than baseline forces (p = .043). Heavy objects on the GRT could only be manipulated with FES, and FES increased the level of independence in 25 of 30 ADL comparisons (5 subjects, 6 activities) as compared to baseline. After training, FES was preferred in 21 of 30 comparisons over the typical means of task completion. Of the 40 electrodes implanted, 37 continue to provide excellent stimulated responses and all of the implanted stimulators have functioned without problems. The surgical reconstruction procedures greatly enhanced FES hand function by either expanding the workspace in which to utilize FES (deltoid to triceps transfer), stabilizing the wrist (brachioradialis to wrist extensor transfer), or stabilizing joints (intrinsic tenodesis transfer, FPL split transfer).

CONCLUSION

For five adolescents with tetraplegia, the combination of FES and surgical reconstruction provided active palmar and lateral grasp and release. Laboratory-based assessments demonstrated that the FES system increased pinch force, improved the manipulation of objects, and typically increased independence in six standard ADL as compared to pre-FES hand function. The study also showed that the five adolescents generally preferred FES for most of the ADL tested. Data on the benefits of the implanted FES hand system outside of the laboratory are needed to understand the full potential of FES.

Menstruation and pediatric spinal cord injury

Menstrual characteristics were studied in young women who sustained spinal cord injuries (SCI) prior to puberty or in early adolescence. Subjects were 37 females who were injured prior to age 16 years and who were at least 10 years old at the time of interview; 22 were injured prior to menarche and 15 after menarche. Average age of menarche for females injured before puberty was 12.3 years which is similar to their mothers (mean 12.6 years) and to patients injured after menarche (mean 12.0 years). Of 15 females injured after menarche, seven reported no interruption in menses while eight had interruptions ranging from one to seven months. No significant menstrual problems were noted in either group. This information about menstruation should be included in sexuality teaching of parents and patients when an SCI occurs to a child or adolescent.

Development of an upper extremity FES system for individuals with C4 tetraplegia

The application of functional electrical stimulation (FES) to provide upper extremity function for individuals with C4 tetraplegia is under investigation. In this study, a FES system was designed that allowed one individual with complete C4 tetraplegia to coordinate stimulated lateral or palmar prehension with stimulated arm movements using contralateral shoulder position. The system consisted of percutaneous intramuscular electrodes implanted to muscles for hand grasp and release, supination, elbow flexion, and extension and arm adduction. Due to peripheral denervation, transposition and subsequent stimulation of the paralyzed latissimus dorsi muscle provided elbow flexion and transfer and stimulation of the paralyzed extensor carpi ulnaris muscle provided forearm supination. A suspended sling provided shoulder joint stability. The subject controlled stimulation proportionally using contralateral shoulder motion sensed by a position transducer. Control of stimulated hand grasp and release were coupled with stimulated arm motions so that hand-to-mouth activities could be accomplished with one motion of the contralateral shoulder. With this system, the subject was able to grasp a milk carton placed in the hand and lift and lower it from his mouth to drink from a short straw. He could also scoop a semisolid substance with an adapted spoon and lift and lower it from the work surface to his mouth to eat. The subject required assistance to place the milk carton or spoon in his hand and position the plate for scooping. Further investigation is needed to generate the necessary arm movements to make completion of these tasks possible without assistance and to expand the range of activities possible with the FES system.

Quantitative comparison of grasp and release abilities with and without functional neuromuscular stimulation in adolescents with tetraplegia

In this study, a functional neuromuscular stimulation (FNS) hand system designed by Case Western Reserve University (CWRU) was implemented in 5 adolescents with C5 tetraplegia and hand function with FNS was evaluated and compared to tenodesis abilities using a grasp and release test designed specifically for this purpose. The test involved the unilateral acquisition, movement and release of 6 objects of various sizes and weights. During a single test session, five 30-second trials were performed with each object with and without the FNS system where the number of completions and failures were recorded for each trial. At least 4 and as many as 8 test sessions were conducted with each subject over periods of 1.5 to 3 years. For each subject, test performance with FNS was compared statistically to tenodesis performance and session-to-session consistency was analyzed. Of 30 comparisons (5 subjects and 6 test objects), FNS was more effective in 23 cases (77%), tenodesis was better in 5 instances (17%) and in 2 cases (6%) there was no difference. Subjects were able to manipulate the 3 heaviest test objects only with FNS and in 60% of all cases involving the 3 lighter test objects there were significantly more trials in which there were more completions or fewer failures with FNS. Performance with FNS and tenodesis was generally inconsistent across sessions; possible reasons for these variations are discussed. Overall, the results of this study support those of the only previous investigation that used the grasp and release test to evaluate hand function with FNS in C5 and C6 tetraplegia.

Outcomes of tendon transfer surgery and occupational therapy in a child with tetraplegia secondary to spinal cord injury

OBJECTIVE

Tendon transfer surgery to augment hand function lost to spinal cord injury (SCI) has gained acceptance as a rehabilitation option for adults but has yet to be fully explored in children. In this study, hand function and performance of activities of daily living in an 11-year-old child with an SCI were evaluated before and after surgical transfers of the brachioradialis to the flexor pollices longus and the extensor carpi radialis longus to the flexor digitorum profundus.

METHOD

With the use of a single-subject AB design, repeated measures of pinch force, the Jebsen Test of Hand Function for Children and the Grasp and Release Test were obtained before tendon transfer surgery and at 2 1/2 6, and 12 months after surgery. Activities of daily living were assessed with the Functional Independence Measure (FIM) and the Common Object Test (COT) before surgery and 12 months after surgery.

RESULTS

Each assessment revealed a significant improvement in hand function after surgery. Pinch force was measurable only after tendon transfers and increased throughout the first year. By two standard deviation analyses, after surgery there were significantly more task completions for all Grasp and Release Test objects, and task completion times were shorter for the light and heavy objects of the Jebsen Test of Hand Function for Children. FIM results showed that self-catheterization and cutting food were possible only after surgery, and results of the COT revealed new unilateral and bilateral abilities that facilitated the client's independence in writing, eating, applying toothpaste, and brushing teeth.

CONCLUSION

This single-subject study demonstrates the benefits of tendon transfers for active grasp in a child with an SCI.

Application of functional neuromuscular stimulation to children with spinal cord injuries: candidate selection for upper and lower extremity research

This paper summarizes the results of screening for participation in research programs involving functional neuromuscular stimulation (FNS). It examines the characteristics of a group of children and teenagers with spinal cord injuries (SCI) identified as potential candidates for FNS as defined by the rigorous inclusion criteria of the research studies. One hundred and thirteen children and teenagers under the age of 20 with cervical, thoracic or lumbar level spinal cord injuries were examined for inclusion in an experimental program of FNS to provide standing, walking, or prehension. Although biased towards adolescents with complete midthoracic and midcervical injuries, the age, sex, injury level, etiology, and neurological status of the sample coincided with previously published reports and consisted predominantly of teenage males injured in motor vehicle or sports related accidents. Approximately half of the individuals examined were physically appropriate for research participation without preparatory intervention. Treatment options to prepare individuals for FNS were identified in 25% of those considered inappropriate at the initial evaluation, indicating that the potential user population of clinical systems may be larger than estimates obtained from research applications. Peripheral denervation was the single most prevalent physical impediment to the application of FNS. Although the incidence of lower motor neuron (LMN) involvement was similar in subjects with tetraplegia and paraplegia, those with cervical lesions more frequently exhibited other medical complications that interfered with the application of FNS. Surgical procedures involving transfer of paralyzed but excitable muscles were identified in almost one third of the candidates with tetraplegia who were excluded due to denervation. Of those physically appropriate, psychological factors eliminated several candidates from consideration. Such concerns may also be addressed with suitable intervention in preparation for the clinical application of FNS. Almost 50% of those appropriate for FNS research elected to participate in the programs, with those declining citing the hospitalization, time and travel commitments as the primary factors influencing their decisions. Results suggest that FNS for standing, walking and hand grasp may be an option for a significant percentage of the pediatric SCI population.

Reliability of percutaneous intramuscular electrodes for upper extremity functional neuromuscular stimulation in adolescents with C5 tetraplegia

Chronically indwelling percutaneous intramuscular electrodes were implanted in the upper extremity muscles of five adolescents with C5 or C5-6 tetraplegia in an effort to provide lateral and palmar prehension using the neuroprosthetic system designed by Case Western Reserve University. The responses from 177 electrodes were evaluated at 3-month intervals and included measurements of electrical impedance and an assessment of recruitment properties. Electrode failures were categorized as breakage, an altered stimulated response or adverse sensation during stimulation. Survival probabilities were generated for all electrodes, each muscle group, the volar and dorsal exit sites, intrinsic and extrinsic muscles, and according to the subjects' time postinjury. The overall probability of an electrode surviving to 6 months was 0.75 and the 1 year survival probability was 0.56. Among muscle groups, the finger extensor and thumb adductor electrodes had the highest proportion of failures and the poorest survival likelihoods within the first year after implant. According to the Breslow test, significantly smaller survival chances were predicted for electrodes exiting dorsally and for the newly-injured adolescents (< 1 year postinjury). The cumulative survival likelihoods of this study are smaller than those reported in adult applications using the same electrode design. Factors that may account for the disparate results are discussed.

Functional neuromuscular stimulation: outcomes in young people with tetraplegia

Percutaneous intramuscular functional neuromuscular stimulation (FNS) systems were fitted to the forearms of five adolescents with tetraplegia in an effort to provide active grasp and release. Two assessments designed at Case Western Reserve University to evaluate functional outcomes of FNS in adults were employed. The common object test (COT) was used to assess hand function during five activities of daily living (ADLs): eating, drinking, writing, brushing teeth and applying toothpaste. A usage survey provided information on the frequency of FNS use in environments outside of the laboratory. In addition, interviews were employed using open-ended questions to gain a deeper understanding of the perceptions of FNS in the adolescents' own environments. Based on the COT results, each adolescent was able to perform ADLs with and without FNS. However, FNS allowed unilateral function so that the extremity without FNS was freed to assist in balance or participate in bilateral tasks. Also, FNS reduced the need for multiple devices, providing users with the potential to perform activities in a variety of environments without transporting adaptive equipment. Those who reported using FNS most often obtained hard-bound school books, held pens during classroom and homework assignments, engaged in leisure activities and performed hygiene tasks. FNS was also used as a means to communicate and socialize through hand gestures. Well-known factors that influence the independence of people with tetraplegia also appeared to affect FNS use.

Bipolar latissimus dorsi transposition and functional neuromuscular stimulation to restore elbow flexion in an individual with C4 quadriplegia and C5 denervation

A bipolar latissimus dorsi transposition was performed on a 17-year-old male patient with a C4 spinal cord injury and complete peripheral denervation at C5. Electrical stimulation of the paralyzed but excitable latissimus dorsi provided elbow flexion that could not be achieved with the paralyzed and denervated elbow flexors. The muscle was attached from the coracoid to the ulna allowing the elbow to be flexed with the forearm and wrist maintained in the neutral position. Following a 6-week immobilization period, the transposed muscle was exercised daily with intramuscular stimulation to increase both strength and endurance. By the fourth month after surgery, the subject could control elbow flexion proportionally with contralateral shoulder elevation using a shoulder position transducer. Functionally, the subject was able to use the neuroprosthetic system to bring his hand to his mouth and feed himself with the aid of a universal cuff and a support to stabilize the shoulder.

The application of a modified neuroprosthetic hand system in a child with a C7 spinal cord injury. Case report

A neuroprosthetic hand system developed at Case Western Reserve University has been modified for use by an 8 year old child with an incomplete C7 spinal cord injury. This system has been adapted to accommodate voluntary thumb and finger extension, and provides stimulated finger flexion and thumb position for lateral and palmar prehension. Three months were required to develop grasp with sufficient strength and coordination for functional use. This period consisted of: implantation and immobilization of percutaneous intramuscular electrodes; stimulated exercise of the muscles of the hand and forearm; programming grasp patterns; and system training. Functional assessments show that the neuroprosthetic hand system allows the subject to perform unilateral and bilateral tasks that were otherwise impossible or were previously performed bimanually. The ability to perform activities of daily living with one hand frees the contralateral upper extremity to be used either for balance which increases the work area, or to stabilize an object allowing manipulation with the instrumented hand. Telephone interviews suggest that the hand system is used on a consistent basis at home and school. This single subject application indicates that a stimulation system designed for adults with C5-6 spinal cord injuries can enhance hand function and facilitate independence in a child with a low level cervical lesion.

Returning to school after a spinal cord injury: perspectives from four adolescents

A phenomenological approach was used to explore the experience of returning to school following a spinal cord injury. Four adolescents who sustained spinal cord injuries and returned to premorbid school environments were interviewed concerning their perceptions, feelings, and experiences of returning to school. The responses were coded into six themes: people, role change, self-image, coping strategies, accessibility, and feelings. The themes were discussed as to their relevance on returning to school following a spinal cord injury. The research participants' suggestions on ways to ease the transition from the rehabilitation environment to the school environment and implications of the study are included.