1/38. 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 = spinal (Clic here for more details about this article) |
2/38. Primary pelvic hydatid cyst: an unusual cause of sciatica and foot drop.STUDY DESIGN: A case report of primary pelvic hydatid cyst causing sciatica and foot drop. OBJECTIVE: To document the occurrence of primary pelvic hydatid cyst as one of the hidden causes of lower limb weakness and foot drop, and to recommend inclusion of the pelvic cavity when assessing sciatica and foot drop. SUMMARY OF BACKGROUND DATA: It is common to see foot drop caused by peripheral lesions around the knee or disc herniation in the lumbar spine, but if these sites were excluded, the pelvic cavity must be examined for hidden disease that may explain the cause of foot drop and sciatica. methods: The authors involved in the care and management of this patient were interviewed and all medical records, radiologic investigations, and related literature were reviewed. RESULTS: After exclusion of spinal and peripheral causes of foot drop, computed tomography of the pelvis showed a well-localized cystic swelling in the right side of the pelvis over the lumbosacral plexus roots. Surgical excision of the cyst resulted in partial recovery of the foot drop at 3 years of follow-up. CONCLUSION: Primary pelvic hydatid cyst rarely causes pressure on the lumbosacral plexus. This was a case of hydatid cyst in the pelvis causing sciatica and foot drop, and it indicates the pelvis as a hidden source of sciatica and foot drop. After surgical excision followed by 4 months' mebendazole therapy, there was no evidence of recurrence on long-term follow-up.- - - - - - - - - - ranking = 1keywords = spinal (Clic here for more details about this article) |
3/38. Lumbar spinal stenosis causing congenital clubfoot.Congenital lumbar spinal stenosis is believed to rarely cause neurologic symptoms during childhood. We present a 16-year-old boy with bilateral congenital clubfeet surgically corrected by tendo Achillis releases at 2 years of age who presented with progressive, bilateral footdrop. magnetic resonance imaging of his lumbosacral spine showed severe spinal stenosis at the L3-5 vertebrae. Congenital lumbar spinal stenosis is probably an under-recognized cause of lower extremity neurologic abnormalities, including clubfoot deformity. magnetic resonance imaging has made this eminently treatable disorder easier to recognize.- - - - - - - - - - ranking = 93.286687362593keywords = spinal stenosis, spinal, stenosis (Clic here for more details about this article) |
4/38. 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 = 6keywords = spinal (Clic here for more details about this article) |
5/38. Brainstem conundrum: the Chiari I malformation.PURPOSE: To describe the Chairi I Malformation in relation to the anatomy of the brain and spinal cord, the common manifestations of the condition, diagnostic considerations, and management for the primary care provider. DATA SOURCES: Extensive review of the world-wide scientific literature on the condition, supplemented with actual case studies. CONCLUSIONS: The adult Chairi I Malformation is an insidious congenital brainstem anomaly that consists of caudal displacement of the cerebellar tonsils, brainstem and fourth ventricle into the upper cervical space, resulting in overcrowding of the posterior fossa. IMPLICATIONS FOR PRACTICE: Due to the vague, and often ambiguous presenting symptoms of Chiari I Malformation, many patients are misdiagnosed with conditions such as multiple sclerosis, fibromyalgia, chronic fatigue syndrome, or psychiatric disorders. patients frequently experience symptoms months to years prior to accurate diagnosis and often incur irreversible neurologic deficits.- - - - - - - - - - ranking = 1keywords = spinal (Clic here for more details about this article) |
6/38. 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 = 2keywords = spinal (Clic here for more details about this article) |
7/38. Primary spinal extradural hydatid cyst in a child: case report and review of the literature.Spinal hydatid cyst is a rare but serious condition. An 8-year-old boy presented with back pain, progressive weakness and numbness in both legs. magnetic resonance imaging (MRI) of the lumbar region showed a cystic lesion with regular contour located in extradural space. There was cerebrospinal fluid- (CSF-) like signal intensity on T1- and T2-weighted images. The lesion had excessively compressed the dural sac and caudal roots, and expanded to the L3 and L4 neural foramina. The case was explored with L2, L3, L4 laminectomy and the hydatid cyst was removed totally. The clinical presentation, diagnosis and surgical treatment of this rare case of spinal hydatid disease is discussed, and all available cases of primary extradural hydatid cyst reported in the literature are presented.- - - - - - - - - - ranking = 6keywords = spinal (Clic here for more details about this article) |
8/38. Exertional myelopathy in type 2 congenital kyphosis.STUDY DESIGN: A case of lower-extremity myelopathy induced by physical exertion in a patient with Type 2 (failure of segmentation) congenital kyphosis is reported. OBJECTIVE: To describe the uncommon presentation of neurologic sequelae in a patient with Type 2 congenital kyphosis. SUMMARY OF BACKGROUND DATA: Various reports have described neurologic sequelae in patients with Type 1 (failure of formation) congenital kyphosis. To the authors' knowledge, no case of Type 2 congenital kyphosis leading to neurologic symptoms has been reported. methods: A 17-year-old boy presented with a 3-year history of progressively worsening midthoracic back pain. During exertion, numbness developed along the posterior aspects of his legs, and he experienced a wobbly sensation in his lower extremities that prevented his participation in athletic activities. His static and dynamic neurologic examination was unremarkable. However, he developed a wide-based clumsy myelopathic gait when he was asked to run in the halls of the clinic. magnetic resonance imaging demonstrated that the spinal cord was draped over the posterior vertebral body of T10. Anterior thoracic spinal cord decompression and fusion were performed through a seventh rib thoracotomy using a structural rib graft to fill the defect. The anterior 1 cm of bone was left intact so as not to cause any additional instability. RESULTS: The patient tolerated the procedure well and had complete resolution of his exertionally dependent myelopathic symptoms. At this writing, 3 years after surgery, he is involved in the Navy ROTC program. CONCLUSIONS: Although Type 2 congenital kyphosis is a rare entity, it should be followed carefully and corrected surgically when appropriate. A history of exertional myelopathy may be an early sign of spinal cord impingement and is an indication for surgical decompression.- - - - - - - - - - ranking = 3keywords = spinal (Clic here for more details about this article) |
9/38. Congenital spondylolysis of the axis with associated myelopathy. Case report.Cervical spondylolysis is a rare clinical entity and occurs predominantly at the C-6 level. The authors describe a patient with congenital spondylolysis of the axis that caused myelopathy. The patient was a 57-year-old woman with long-standing gait disturbance. Plain cervical radiography revealed a radiolucent defect across the pedicle of the axis. magnetic resonance imaging of the cervical spine in the neutral, flexion, and extension neck positions as well as a computerized tomography myelography in the neutral neck position failed to demonstrate any spinal cord compression. When she rotated her neck, however, the spinal cord was caught between the hypertrophic anterior arch of the atlas and posterior part of the slipped pedicle of the axis on the contralateral side. The spinal cord was transformed into a pear shape. Mechanical injury to the spinal cord seemed to explain her neurological presentation. This is, to the authors' knowledge, the 15th case of axial spondylolysis and the sixth case of spinal cord involvement of the cervical spondylolysis. No cases involving myelopathy secondary to such a unique mechanism have been reported previously in the literature.- - - - - - - - - - ranking = 5keywords = spinal (Clic here for more details about this article) |
10/38. Spasticity, strength, and gait changes after surgery for cervical spondylotic myelopathy: a case report.STUDY DESIGN: A case report with repeated measures is presented. OBJECTIVE: To describe an objective method for evaluating changes in upper- and lower-extremity spasticity and strength, as well as temporal and kinematic gait variables, after surgical intervention for cervical spondylotic myelopathy. SUMMARY OF BACKGROUND DATA: Degenerative cervical spinal disease is a common disorder, with some form of spondylosis demonstrated radiographically in more than 80% of those older than 55 years. Normative pre- and postoperative objective data quantifying spasticity, strength, and gait do not exist. methods: A 65-year-old woman underwent C2-C3 anterior cervical discectomy and fusion for progressive myelopathy secondary to a spondylosis and disc herniation. The measure for spasticity and strength at the ankles and elbows and a gait analysis were collected before surgery and at 11 days, 3 and 6 months after surgery. Spasticity and strength were assessed using a dynamometer, and a six-camera video system was used to record the gait. RESULTS: Preoperative left elbow flexor spasticity was more than 10 times greater than the values for the able bodies. It was reduced to normal levels after surgery. Substantial presurgery weakness was present in the elbow flexors and extensors bilaterally. elbow extensor strength was at able-body levels after surgery. gait speed was 57% of the able-body level before surgery and 78% of the able-body level 6 months after surgery. CONCLUSIONS: This case study demonstrated the role of biomechanics in characterizing impairments associated with cervical spondylosis and its surgical intervention. Measures for spasticity, strength, and gait taken before and after surgery indicated a favorable outcome. This report provides a foundation for the continued use of biomechanical methods to measure changes in function and impairments associated with surgical intervention of cervical spine disorders.- - - - - - - - - - ranking = 1keywords = spinal (Clic here for more details about this article) |
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