1/34. Interfacing the body's own sensing receptors into neural prosthesis devices.Functional electric stimulation (FES) is today available as a tool in muscle activation used in picking up objects, in standing and walking, in controlling bladder emptying, and for breathing. Despite substantial progress over nearly three decades of development, many challenges remain to provide a more efficient functionality of FES systems. The most important of these is an improved control of the activated muscles. Instead of artificial sensors for feedback, new developments in electrodes to do long-term and reliable recordings from peripheral nerves emphasize the use of the body's own sensors. These are already installed and optimised through millions of years of natural evolution. This paper presents recent results on a system using electrical stimulation of motor nerves to produce movement and using the natural sensors as feedback signals to control the stimulation that can replicate some of the functions of the spinal cord and its communication with the brain. We have used the nerve signal recorded from cutaneous nerves in two different human applications: (1) to replace the external heel switch of a system for correction of spastic drop foot by peroneal stimulation, and (2) to provide an FES system for restoration of hand grasp with sensory feedback from the fingertip. For the bladder function, the sacral root stimulator is a useful control tool in emptying the bladder. To decide when to stimulate, we are at present carrying out experiments on pigs and cats using cuff electrodes on the pelvic nerve and sacral roots to record the neural information from bladder afferents. This information can potentially be used to inhibit unwanted bladder contractions and to trigger the FES system and thereby bladder emptying. Future research will show whether cuffs and other types of electrodes can be used to reliably extract signals from the large number of other receptors in the body to improve and expand on the use of natural sensors in clinical FES systems.- - - - - - - - - - ranking = 1keywords = muscle (Clic here for more details about this article) |
2/34. Usefulness of gait analysis combined with motor point block in a stroke patient.This clinical note describes a typical case of dynamic varus deformity of the rear foot in a stroke patient. An overactive Tibialis Posterior muscle seemed mainly responsible for the varus deformity. However, this hypothesis was not confirmed by a motor point block of this muscle. It appeared that the Tibialis Posterior and Extensor Hallucis Longus muscles were both involved in the varus deformity. A double motor point block of both the Tibialis Posterior and Extensor Hallucis Longus muscles was performed. Kinematic and kinetic data showed improvement. This case report illustrates the usefulness of gait analysis combined with motor point block in the diagnosis and management of gait disturbance.- - - - - - - - - - ranking = 2keywords = muscle (Clic here for more details about this article) |
3/34. Intermittent falls and fecal incontinence as a manifestation of epileptic negative myoclonus in idiopathic partial epilepsy of childhood.We report two children, suffering from idiopathic partial epilepsy, who started to present, in the same period of time, with epileptic negative myoclonus (ENM) in one lower limb and fecal incontinence (FI). Polygraphic recordings showed that ENM was associated with paroxysmal activities distributed over the vertex region. Both ENM and FI disappeared when ethosuximide treatment was started. We hypothesize that, in our patients, ENM in one lower limb and FI depended on a transitory impairment, caused by epileptic activity that altered the functionality of nearby cortical areas, located in fronto-mesial regions, involved in the control of the muscular tone of the lower limbs and of the pelvic floor muscles.- - - - - - - - - - ranking = 0.5keywords = muscle (Clic here for more details about this article) |
4/34. The giant axonal neuropathy--clinical and hisotological aspects, differential diagnosis and a new case.The giant axonal neuropathy (GAN) is morphologically characterized by axonal swellings and accumulations of neurofilaments in giant axons and other cell types. Curly hair is not a constant finding. The clinical course is progressive and mostly starts in early childhood. We report the case of a boy aged 6 years at the time of sural nerve and muscle biopsy. Suralis nerve showed a reduced numerical density of myelinated fibres with a consecutive endoneural fibrosis. Morphometric investigation revealed a pronounced reduction of fibres measuring 8-12 microm in diameter. Giant axons were seen in relatively low number and were not very large with a maximum diameter of 18 microm. They had a relatively thin myelin sheet proved also by the high G ratio in the histogram. Many onion bulb formations of schwann cells were present. There are only few reports of giant axons with such low maximum diameter in cases with GAN, the lowest maximum diameters being reported in case reports on Japanese children. Up to now, this is the first report of a non-Japanese patient with a low maximum diameter of giant axons of less than 20 microm in peripheral nerve biopsy. Ultrastructurally, typical accumulations of neurofilaments and osmiophilic aggregates were found in giant axons. Other diagnoses with occurrence of giant axons could be excluded in view of the absence of specific findings. Sporadic or familial cases with giant axons are discussed. Sceletal muscle biopsy (M. quadriceps femoris) showed neurogenic affection with presence of small angulated atrophic muscle fibres.- - - - - - - - - - ranking = 1.5keywords = muscle (Clic here for more details about this article) |
5/34. Tibialis posterior insufficiency occurring in a patient without peronei: a mechanical etiology.A patient presented with a painful flatfoot deformity, which developed after the onset of a drop-foot secondary to a herniated lumbar disk. On examination, the only functioning muscles were her gastrocnemius-soleus complex and her intrinsic toe flexors. Her affected foot had taken the classic deformity seen with tibialis posterior dysfunction--a valgus heel, midfoot collapse and an abducted forefoot. Peroneus brevis was not functioning and therefore could not be implicated as part of the etiology of this patient's acquired flatfoot deformity. The mechanism in which the ground reaction force produces the foot deformity in a tibialis posterior insufficient foot will be presented.- - - - - - - - - - ranking = 0.5keywords = muscle (Clic here for more details about this article) |
6/34. spinal cord stimulation facilitates functional walking in a chronic, incomplete spinal cord injured.DESIGN: This paper describes a treatment paradigm to facilitate functional gait in a quadriplegic, asia C spinal cord injured (SCI), wheelchair-dependent subject who presented with some large fiber sensation, sub-functional motor strength in all lower limb muscles, and moderate spasticity. The study utilizes partial weight bearing therapy (PWBT) followed by epidural spinal cord stimulation (ESCS) with the assumption that both treatments would be necessary to elicit a well organized, near effortless functional gait with a walker. Function is defined in terms of accomplishing task-specific activities in the home and community. OBJECTIVES: To demonstrate the feasibility and benefits of combined PWBT and ESCS therapies aimed at promoting functional gait in a wheelchair-dependent asia C SCI subject. SETTING: The Clinical neurobiology and bioengineering research laboratories at Good Samaritan Regional Medical Center, Phoenix, arizona, USA, and the Department of bioengineering, arizona State University, Tempe, arizona, USA. methods: The study began with the application of PWBT. The subject walked on the treadmill until a plateau in gait rhythm generation was reached. Subsequently, ESCS, applied to the lumbar enlargement, was utilized to facilitate PWBT and, later, over-ground walking for a standard distance of 15 m. gait performance was analyzed by measuring average speed, stepping symmetry, sense of effort, physical work capacity, and whole body metabolic activity. RESULTS: PWBT led to improved stereotypic stepping patterns associated with markedly reduced spasticity, but was insufficient for over-ground walking in terms of safety, energy cost, and fatigue. ESCS with PWBT generated immediate improvement in the subject's gait rhythm when appropriate stimulation parameters were used. When compared to the non-stimulated condition, over-ground walking with ESCS across a 15 m distance was featured by a reduction in time and energy cost of walking, sense of effort, and a feeling of 'lightness' in the legs. After a few months of training, performance in speed, endurance, and metabolic responses gradually converged with/without ESCS at this short distance, suggesting a learned response to these conditions. However, at longer distances (eg, 50-250 m), performance with ESCS was considerably superior. The subject was able to perform multiple functional tasks within the home and community with ESCS. CONCLUSION: We propose that ESCS augments the use-dependent plasticity created by PWBT and may be a valuable adjunct to post-SCI treadmill training in asia C subjects. We also conclude that ESCS elicits greater activation of an oxidative motor unit pool, thereby reducing the subject's sense of effort and energetic cost of walking.- - - - - - - - - - ranking = 0.5keywords = muscle (Clic here for more details about this article) |
7/34. Treatment of craniocervical spine lesion with osteogenesis imperfecta: a case report.STUDY DESIGN: A case report of craniocervical spine lesions including basilar impression, atlantoaxial dislocation, and syringomyelia, with osteogenesis imperfecta is presented, and the literature is reviewed. OBJECTIVE: To discuss the problems involved in the surgical management of craniocervical spine lesion with osteogenesis imperfecta. SUMMARY OF BACKGROUND DATA: osteogenesis imperfecta is known to have various spine lesions as complications. However, few reports have described craniocervical lesions associated with osteogenesis imperfecta. methods: A 14-year-old girl with osteogenesis imperfecta, Silence classification IVB, experienced difficulty walking, with marked motor disturbance and muscle weakness in the extremities. Deep tendon reflexes were exaggerated bilaterally in the upper and lower extremities, and positive Babinski reflex and ankle clonus were observed bilaterally. Basilar impression, atlantoaxial dislocation, and syringomyelia were shown by plain radiography, tomography, three-dimensional computed tomography, and magnetic resonance imaging. RESULTS: In the reported patient, posterior fossa decompression and atlantoaxial posterior fusion could not be performed because the foramen magnum and upper cervical spine invaginated to the base of the skull. Therefore, occipitocervical spine fusion using titanium loop and wires was performed at the reduced position of the atlantoaxial dislocation, resulting in improvement of neurologic deficits. CONCLUSIONS: For patients with atlantoaxial dislocation, syringomyelia, and basilar impression without clinical symptoms or signs of brain stem compression, occipitocervical spine fusion alone at the reduction of the atlantoaxial dislocation may be indicated because these procedures improve neurologic deficits and prevent postoperative development of basilar impression and enlargement of syringomyelia.- - - - - - - - - - ranking = 0.5keywords = muscle (Clic here for more details about this article) |
8/34. Occurrence of subdural hematoma and resolution of gait disturbance in a patient treated with shunting for normal pressure hydrocephalus.A 66-year-old man with gait disturbance was diagnosed with normal pressure hydrocephalus (NPH) and treated with ventriculoperitoneal shunting using a programmable valve. The valve ultimately set at a pressure of 40 mm H(2)O after higher settings no longer relieved symptoms. However, this pressure setting was excessively low and was associated with occurrence of bilateral subdural hematomas. Paradoxically, this event was associated with stable improvement of gait. Our patient's gait disturbance was unassociated with muscle weakness, spasticity, cerebellar ataxia, or Romberg's sign, and, therefore, was consistent with a frontal gait disorder. Cerebral cortical blood flow as measured after shunting by single photon emission computed tomography (SPECT) was slightly increased from the value before shunting, possibly because of intracranial hypotension related to the valve setting. Lasting improvement of gait in our case may be a result of increased blood flow in the supplementary motor area (SMA).- - - - - - - - - - ranking = 0.5keywords = muscle (Clic here for more details about this article) |
9/34. Multimodality management of a giant cell tumor arising in the proximal sacrum: case report.STUDY DESIGN: Descriptive. OBJECTIVE: To outline a novel multimodality approach for a difficult surgical resection of a giant cell tumor in the cephalad portion of the sacrum. SUMMARY OF BACKGROUND DATA: giant cell tumors of the sacrum are rare primary bone tumors. Recent reports have demonstrated diminished giant cell tumor recurrence with cryosurgery by using a "direct pour" technique with liquid nitrogen. Although successful in decreasing tumor recurrence, this technique is accompanied by a 4%-8% rate of skin necrosis and high rates of pathologic fracture. The authors describe resection and a novel, controlled method of argon-based cryotherapy (followed by a unique pelvic reconstruction) for a large, difficult giant cell tumor of the sacrum. methods: A 29-year-old woman presented with complaints of right foot drop and decreased sensation of the right buttock, posterior thigh, posterior calf, and lateral aspect of the right foot. Radiographic evaluation revealed a mass in the right sacrum; histologic examination of CT-guided biopsy revealed a giant cell tumor. A combined anterior abdominal and posterior sacral approach was performed, the tumor was resected, and the margin of the cavity was treated with controlled argon-based cryotherapy. The combination of thermocouples, electromyographic monitoring, and rapid freeze-thaw cycles allowed a controlled ablation of the tumor margin while ensuring that surrounding structures, such as the rectal wall, sacral nerves, and gluteal muscles, were not damaged. Posterior spinal fusion L4 to sacrum, posterior spinal instrumentation L4 to pelvis, and allograft reconstruction of the right sacrum were performed. RESULTS: The patient recovered well without skin necrosis or pathologic fracture. Urinary and fecal continence were preserved. At the 20-month follow-up the patient has no evidence of local tumor recurrence and is fully ambulatory without a brace or narcotic medication. CONCLUSION: A novel multimodality approach, consisting of resection, controlled cryosurgery, and a unique lumbopelvic reconstruction, was safe and successful in managing a challenging proximal sacral giant cell tumor. Twenty months after surgery the patient has excellent bowel and bladder control, no tumor recurrence, and functional ambulation without a brace or pain.- - - - - - - - - - ranking = 0.5keywords = muscle (Clic here for more details about this article) |
10/34. gait rehabilitation in a patient affected with charcot-marie-tooth disease associated with pyramidal and cerebellar features and blindness.Charcot-Marie-Tooth (CMT) disease, an inherited neuropathy characterized by length-dependent degeneration of the motor and sensory nerve fibers with consequent distal muscle atrophy and sensory reduction, can be associated with symptoms and signs of involvement of the central nervous system and/or cranial nerves. We present a patient with relatively severe CMT, cerebellar ataxia, pyramidal involvement, and blindness due to Leber's hereditary optic neuropathy. The patient presented with poor standing and gait, with consequent severe disability. Factors responsible for the patient's functional impairment (plantarflexor failure, footdrop, foot rotation, knee flexor contracture, poor proprioception, cerebellar dysfunction, spastic paraparesis, blindness) were identified and addressed by a rehabilitation management, which included, as a main intervention, ankle stabilization by drop-foot boots instead of ankle-foot orthoses. Improved balance and independent ambulation resulted from rehabilitation.- - - - - - - - - - ranking = 0.5keywords = muscle (Clic here for more details about this article) |
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