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Biomedical subjects

James J McCarthy

Publications and source records attributed to James J McCarthy.

At least 19 recordsLinked to original sources
PubMed2006

Hip disorders in children who have spinal cord injury.

Little has been written regarding the assessment and treatment of hip disorders in children who have underlying paralysis. Each year approximately 2000 people younger than 20 years of age suffer a spinal cord injury (SCI). This compares with a larger number of children who have other forms of neurologic disorders, such as myelodysplasia, which affects approximately 6000 newborns annually in the United States, and for which there is a large body of literature describing the natural history and treatment of hip disorders in children who have myelodysplasia. This article focuses on hip disorders in children who have SCI, although there is clearly commonality in hip disorders that transcends many neurologic disorders.

Child↗
PubMed2006

Scoliosis in the child with cerebral palsy.

Scoliosis is common in children with cerebral palsy. The incidence and curve pattern depend on the degree of neurologic involvement. These children carry a higher risk of complications because of the increased presence of associated medical comorbidities. Accordingly, a careful preoperative evaluation is required that should involve assessment of the patient's pulmonary, nutritional, gastrointestinal, and neurologic systems as well as a thorough evaluation of the spine and musculoskeletal system. Children with progressive curves >40 degrees to 50 degrees are candidates for spinal fusion, especially when the deformity interferes with sitting or is unresponsive to bracing. The goal of surgery is to obtain a stable, balanced, and painless spinal fusion. Although posterior spinal fusion with multisegmental fixation is the most common technique, others, such as anterior release and/or fusion or combined procedures, are now considered. In patients with significant pelvic obliquity or who are at risk of developing pelvic obliquity, instrumentation should extend to the pelvis, particularly in the nonambulatory child.

Cerebral Palsy↗
PubMed2005

Assessment of wavelet analysis of gait in children with typical development and cerebral palsy.

The objective of this study was to examine the use of the continuous wavelet transform (CWT) on surface electromyographic (sEMG) signals acquired from the lower extremity muscles during gait in children with typical development (TD) and cerebral palsy (CP). This was done to explore the possibility of developing a quantitative assessment scale of motor function based on time-frequency information. An initial study was conducted on retrospective gait data from three children, matched in gender and in anthropometric variables but with differing levels of walking ability. EMG data were extracted from five lower extremity muscles to assess the degrees of differentiation. The data were processed using the CWT to derive an average scalogram, from which the instantaneous mean frequency (IMNF) was calculated. Principal component analysis was used to assess the differences between the curves. Preliminary results indicated that for select lower extremity muscles, there was a significant deviation in the IMNF curves in the child with CP as compared to the child with TD. Furthermore, as motor impairment increased, total percent explained variance to the TD curves decreased. This suggests that it might be possible to derive a physiologically based quantitative index for assessing motor function and for assessing clinical treatments in CP using the wavelet analysis.

Algorithms↗
PubMed2005

Immediate effect of percutaneous intramuscular stimulation during gait in children with cerebral palsy: a feasibility study.

The feasibility of percutaneous intramuscular functional electrical stimulation (P-FES) in children with cerebral palsy (CP) for immediate improvement of ankle kinematics during gait has not previously been reported. Eight children with CP (six with diplegia, two with hemiplegia; mean age 9 years 1 month [SD 1 y 4 mo; range 7 y 11 mo to 11 y 10 mo]) had percutaneous intramuscular electrodes implanted into the gastrocnemius (GA) and tibialis anterior (TA) muscles of their involved limbs. Stimulation was provided during appropriate phases of the gait cycle in three conditions (GA only, TA only, and GA/TA). immediately after a week of practice for each stimulation condition, a gait analysis was performed with and without stimulation. A significant improvement in peak dorsiflexion in swing for the more affected extremity and dorsiflexion at initial contact for the less affected extremity were found in the GA/TA condition. Clinically meaningful trends were evident for improvements in dorsiflexion kinematics for the more and less affected extremities in the TA only and GA/TA conditions. The results suggest that P-FES might immediately improve ankle kinematics in children with CP.

Ankle↗
PubMed2005

Musculoskeletal infections in children: basic treatment principles and recent advancements.

Pediatric musculoskeletal infections are common disorders that can result in significant disability. Because the understanding, diagnosis, and treatment of infections of the bones, joints, and soft tissues have continued to improve over time, it is important for orthopaedic surgeons to have an understanding of the etiology, diagnosis, basic treatment principles, and recent advancements to achieve successful outcomes. Although each infectious process is unique, there are certain treatment principles that apply to all pediatric musculoskeletal infections. These include prevention, a prompt and accurate diagnosis, and timely medical and/or surgical intervention. Continued evaluations are mandatory to assure good long-term outcomes. Because the effects of infection may last beyond the acute episode in pediatric patients, long-term follow-up is needed to assess for late sequelae such as angular deformities and limb-length inequalities.

Arthritis, Infectious↗
PubMed2004

Direct effect of percutaneous electric stimulation during gait in children with hemiplegic cerebral palsy: a report of 2 cases.

The feasibility of using percutaneous intramuscular functional electric stimulation (FES) in children with cerebral palsy (CP) as a method to improve ankle kinematics and kinetics during gait was investigated. Two children with right hemiplegic CP had percutaneous intramuscular electrodes implanted into the gastrocnemius and tibialis anterior muscles of the involved limb. FES was provided during the gait cycle using force-sensing foot switches to detect gait phase transitions. The children ambulated using FES under 3 conditions (gastrocnemius on, tibialis anterior on, gastrocnemius and tibialis anterior on). For each condition, two 45-minute walking sessions were conducted per day for 1 week. Immediately after each week of practice, a gait analysis was performed at the subject's self-selected walking speed for that stimulation condition and without stimulation. Both children demonstrated improvements in ankle dorsiflexion angle at initial contact, peak dorsiflexion during swing, mean dorsiflexion during swing, and ankle work during early stance with tibialis anterior stimulation alone and combined gastrocnemius and tibialis anterior stimulation. Improvements in ankle work were found during late stance for both children with all stimulation conditions. These results suggest that percutaneous intramuscular FES was effective in improving aspects of ankle kinematics and kinetics of 2 children with hemiplegic CP.

Ankle Joint↗
PubMed2004

Incidence and degree of hip subluxation/dislocation in children with spinal cord injury.

BACKGROUND/OBJECTIVES: The purpose of this study was to verify the incidence and degree of hip subluxation/dislocation in children with spinal cord injury (SCI) and determine the association between age of injury and hip subluxation/dislocation. METHODS: All children from our SCI database with complete data through 2001, who had follow-up of > 2 years and were at least 14 years of age at follow-up, were included in the study. Hip subluxation was defined as a migration index (MI) > 20%. The medial joint space (MJS) was measured and considered abnormal if > 7 mm. The patients were divided into 2 groups: those < or = 10 years of age at the time of injury (group 1) and those > 10 years of age (group 2). There were 62 patients included in the study: 29 in group 1 and 33 in group 2. The mean age at the time of injury was 4.6 years for group 1 and 14.3 years for group 2. RESULTS AND CONCLUSION: Forty-eight percent of patients had at least one hip with subluxation/dislocation: 93% in group 1 and 9% in group 2. The mean MI (for those that were abnormal) was 44% in group 1 and 25% in group 2. The MJS was abnormal in 78% of hips in group 1 and 38% in group 2. Thirteen patients in group 1 and 1 patient in group 2 underwent surgery to better contain the hip. Numerous other radiographic hip irregularities were identified. This study demonstrates a high rate of hip subluxation/dislocation in children with SCI who had onset of injury before 10 years of age.

Adolescent↗
PubMed2004

Comparison of percutaneous and surface functional electrical stimulation during gait in a child with hemiplegic cerebral palsy.

The purpose of this brief report was to compare the immediate effects of surface functional electrical stimulation (S-FES) and percutaneous functional electrical stimulation (P-FES) of the tibialis anterior applied during gait in a child with hemiplegic cerebral palsy. A three-dimensional gait analysis was conducted while an 11-yr-old girl with right hemiplegia walked with S-FES, P-FES, and no stimulation. The results indicated that both P-FES and S-FES increased dorsiflexion at initial contact, peak dorsiflexion in swing, and mean dorsiflexion in swing compared with walking without stimulation. The increase in dorsiflexion was greater with P-FES as compared with S-FES. Ankle absorption work was improved with both types of stimulation, whereas ankle generation work increased only with P-FES. This report suggests that S-FES and P-FES may have different immediate effects on gait due to issues such as muscle contraction strength, sensory feedback, and control systems for stimulation.

Ankle↗
PubMed2003

Illustrating the coupled human-environment system for vulnerability analysis: three case studies.

The vulnerability framework of the Research and Assessment Systems for Sustainability Program explicitly recognizes the coupled human-environment system and accounts for interactions in the coupling affecting the system's responses to hazards and its vulnerability. This paper illustrates the usefulness of the vulnerability framework through three case studies: the tropical southern Yucatán, the arid Yaqui Valley of northwest Mexico, and the pan-Arctic. Together, these examples illustrate the role of external forces in reshaping the systems in question and their vulnerability to environmental hazards, as well as the different capacities of stakeholders, based on their access to social and biophysical capital, to respond to the changes and hazards. The framework proves useful in directing attention to the interacting parts of the coupled system and helps identify gaps in information and understanding relevant to reducing vulnerability in the systems as a whole.

Agriculture↗
PubMed2003

A framework for vulnerability analysis in sustainability science.

Global environmental change and sustainability science increasingly recognize the need to address the consequences of changes taking place in the structure and function of the biosphere. These changes raise questions such as: Who and what are vulnerable to the multiple environmental changes underway, and where? Research demonstrates that vulnerability is registered not by exposure to hazards (perturbations and stresses) alone but also resides in the sensitivity and resilience of the system experiencing such hazards. This recognition requires revisions and enlargements in the basic design of vulnerability assessments, including the capacity to treat coupled human-environment systems and those linkages within and without the systems that affect their vulnerability. A vulnerability framework for the assessment of coupled human-environment systems is presented.

Adaptation, Psychological↗
PubMed2003

Neural substrates of tactile imagery: a functional MRI study.

fMRI investigation on the neural substrates involved in tactile imagery is reported. Healthy subjects performed mental imagery of tactile stimulation on the dorsal aspect of the right hand. The results were compared with the regions of activation during the actual tactile stimulation. During imagery, contralateral primary and secondary somatosensory areas were activated along with activation in the left parietal lobe. Activations in left inferior frontal gyri (Brodmann's area 44), left dorsolateral prefrontal area, left precentral gyrus, left insula, and medial frontal gyrus were also observed. In the basal ganglia, activation in the left thalamus (ventral posteromedial nucleus) and putamen was found. Our results suggest that the primary and secondary somatosensory areas are recruited during tactile imagery, and have partially overlapping neural substrates for the perception of tactile stimulation.

Adult↗
PubMed2003

The effects of limb lengthening on growth.

The purpose of this study was to determine the effects of limb lengthening on the rate of growth of the lengthened limb. The rate of growth of the lengthened and control (contralateral) limb segment were determined radiographically pre- and postoperatively in 19 skeletally immature patients (20 limbs). There were 13 femoral and seven tibial lengthenings. The mean age at the time of lengthening was 9.4 years (range 4.2-12.3). The limbs were lengthened by a mean of 6.7 cm (24%). Mean follow-up was 3.6 years. No significant difference was found between the change in the rate of growth of the lengthened and control limb (P=0.59). This was true for both the femur and the tibia, when analyzed separately. This study indicates that the change in the rate of growth between the lengthened and control limbs did not vary significantly in our patient group.

Bone Lengthening↗
PubMed2002

Three-year follow-up of an implanted functional electrical stimulation system for upright mobility in a child with a thoracic level spinal cord injury.

PURPOSE: The purpose of this study was to compare the use of a functional electrical stimulation (FES) system with the use of knee-ankle-foot orthoses (KAFO) for upright mobility over a 3-year period in a child with a spinal cord injury (SCI). METHODS: A 13-year-old boy with a T8 complete SCI received a lower extremity implanted FES system. Electrodes were implanted for knee extension and for hip extension, abduction, and adduction. After training and at annual intervals, independence and timeliness in completing 7 upright mobility activities with FES and KAFO, as well as stimulated muscle strength, were assessed. RESULTS: Results have shown that FES provided independence equal to that of KAFO for all activities. Four activities were accomplished more quickly with FES, including donning the system, reaching a high object, transferring to a high surface, and walking 6 m. A floor-to-stand transfer was faster with KAFO. Functional results and stimulated muscle strength have remained stable over the 3-year period. CONCLUSION: The results indicate that FES can provide function equal to or faster than KAFO in a child with a T8 complete SCI and that performance with the FES system can remain stable for at least 3 years.

Adolescent↗
PubMedDate not supplied

Use of functional electrical stimulation to augment traditional orthopaedic surgery in children with cerebral palsy.

The purpose of this study was to compare the functional outcomes of traditional lower extremity orthopaedic surgery to more limited surgery augmented with functional electrical stimulation (FES) applied while walking. Seventeen ambulatory children with cerebral palsy participated in this prospective pretest-posttest control group study. The surgical group (nine subjects) underwent traditional orthopaedic procedures. The FES group (eight subjects) underwent placement of percutaneous intramuscular FES electrodes and limited orthopaedic surgical procedures. Postoperatively, they were provided with an FES home walking program. One year after intervention, all children (combined data) showed improvements in passive range of motion, gait spatiotemporal parameters, and gross motor function (P < 0.05). No differences were seen between groups before or after intervention. The FES group underwent 4.5 fewer ablative procedures per child than the surgical group. These results suggest that FES in combination with more limited surgery may provide similar functional gains with fewer ablative procedures than traditional orthopaedic surgery.

Cerebral Palsy↗