Biomechanical response in the ankle to stimulation of lumbosacral nerve roots with spiral cuff multielectrode--preliminary study.
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Biomechanical response in the ankle to tetanic stimulation of the lumbosacral root was investigated to assess the potential for lower limb functional neurostimulation. Myotomal response in the leg was measured as the three-dimensional isometric torque in the ankle after extradural tetanic stimulation of the L3-S1 roots exposed surgically for herniated disc removal in five patients. The cuff multielectrode was employed to investigate functional topography of the roots by monopolar, bipolar, and tripolar electrode configurations. Four response patterns in the direction of three-dimensional torque vectors were observed. The L-5 and S-1 roots had the same response pattern, but S-1 roots produced stronger torques. Dorsiflexion torque was not obtained by stimulation of L-5 roots despite coactivation of the tibial anterior and peroneal muscles. Dorsiflexion torques were produced only by stimulating the L-4 roots. More selective bipolar and tripolar stimulations recruited force at higher thresholds and less gain. Additionally, some muscles were not activated by tripolar stimulation of the same root. In one L-4 root, the torque at lower electrical threshold was replaced by inverse torque at higher threshold, providing indirect evidence that different muscles may have motoneuron populations that differ in diameter or location within the root. Although dorsiflexion and plantarflexion torques are functional per se, they are accompanied by foot inversion and leg rotation torques (as well as proximal muscle contractions). Further experimental investigations on direct extradural stimulation of lumbosacral roots, either single or in combination, are recommended to explore the potential of lumbosacral nerve root stimulation for restoration of leg function. (+info)
Migrated disc in the lumbar spinal canal--case report.
(18/1084)
A 49-year-old man who had complained of back pain for 20 years presented with numbness and pain in his left leg persisting for 6 weeks. Magnetic resonance imaging demonstrated a peripherally enhanced intraspinal mass at the L-3 level. The mass was completely removed. The operative and histological findings revealed degenerated disc fragments surrounded by granulation tissue. His symptoms were completely relieved. Migrated disc should be included in the differential diagnosis of patients with a long history of back pain and an intraspinal mass. (+info)
Thermatomal changes in cervical disc herniations.
(19/1084)
Subjective symptoms of a cool or warm sensation in the arm could be shown objectively by using of thermography with the detection of thermal change in the case of radiculopathy, including cervical disc herniation (CDH). However, the precise location of each thermal change at CDH has not been established in humans. This study used digital infrared thermographic imaging (DITI) for 50 controls and 115 CDH patients, analyzed the data statistically with t-test, and defined the areas of thermatomal change in CDH C3/4, C4/5, C5/6, C6/7 and C7/T1. The temperature of the upper trunk and upper extremities of the control group ranged from 29.8 degrees C to 32.8 degrees C. The minimal abnormal thermal difference in the right and left upper extremities ranged from 0.1 degree C to 0.3 degree C in 99% confidence interval. If delta T was more than 0.1 degree C, the anterior middle shoulder sector was considered abnormal (p < 0.01). If delta T was more than 0.3 degree C, the medial upper aspect of the forearm and dorsal aspect of the arm, some areas of the palm and anterior part of the fourth finger, and their opposite side sectors and all dorsal aspects of fingers were considered abnormal (p < 0.01). Other areas except those mentioned above were considered abnormal if delta T was more than 0.2 degree C (p < 0.01). In p < 0.05, thermal change in CDH C3/4 included the posterior upper back and shoulder and the anterior shoulder. Thermal change in CDH C4/5 included the middle and lateral aspect of the triceps muscle, proximal radial region, the posterior medial aspect of the forearm and distal lateral forearm. Thermal change in CDH C5/6 included the anterior aspects of the thenar, thumb and second finger and the anterior aspects of the radial region and posterior aspects of the pararadial region. Thermal change in CDH C6/7 included the posterior aspect of the ulnar and palmar region and the anterior aspects of the ulnar region and some fingers. Thermal change in CDH C7/T1 included the scapula and posterior medial aspect of the arm and the anterior medial aspect of the arm. The areas of thermal change in each CDH included wider sensory dermatome and sympathetic dermatome. There was a statistically significant change of temperature in the areas of thermal change in all CDH patients. In conclusion, the areas of thermal change in CDH can be helpful in diagnosing the level of disc protrusion and in detecting the symptomatic level in multiple CDH patients. (+info)
A 53-year-old male presented with a rare dorsally sequestrated thoracic disc herniation manifesting as acute low back pain and weakness. He had no history of trauma. Magnetic resonance (MR) imaging demonstrated a mass at T10-11 intervertebral level connected with the T-10 disc. Axial MR imaging showed the mass had surrounded and compressed the dural sac from the lateral and dorsal sites. MR imaging with gadolinium-diethylenetriaminepenta-acetic acid showed slight rim enhancement of the lesion. Computed tomography detected no abnormal calcification. The diagnosis was thoracic disc herniation. Laminectomy resulted in rapid and satisfactory recovery. The histological diagnosis was thoracic disc herniation. MR imaging was very effective for the diagnosis based on the connection between the mass and the disc space. The differential diagnosis includes metastatic epidural tumor, epidural hematoma, and epidural abscess. (+info)
When does the patient with a disc herniation undergo lumbosacral discectomy?
(21/1084)
OBJECTIVES: To design a model that could accurately predict eventual lumbar disc surgery in the patient initially presenting with clinical findings of nerve root compression. METHODS: Prospective study in 183 patients with nerve root compression sampled from a primary care population. All patients underwent a standardised history, physical examination, and MRI. Surgery carried out in the next 6 months was recorded. Models were constructed to predict whether patients eventually received surgery. RESULTS: Two models were constructed. Reduced model A was based on baseline findings, only, and contained six variables. Model B incorporated change over time as well and contained 10 variables. The area under the curve (in a receiver operating characteristic) for these models was 0.86 and 0.92, respectively. It was shown that at a probability cut off of 0.60, model B predicted eventual surgery with a sensitivity of 57% and a specificity of 100%. CONCLUSIONS: Given the requirement of a high specificity, eventual operation could be adequately predicted in a sample of 183 patients with clinical nerve root compression. The application of the model in patients with nerve root compression might lead to earlier operation in a subset of patients resulting in a reduction of duration of illness and associated indirect costs. An important prerequisite for future application would be the validation of the prediction rule in another population. (+info)
Transforming and epidermal growth factors in degenerated intervertebral discs.
(22/1084)
We studied the presence of anabolic growth factors in human herniated intervertebral discs (IVD) using a reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry. Messenger RNA (mRNA) was isolated from the nucleus pulposus using oligo (dT)25 superparamagnetic beads and probing with gene-specific primers in RT-PCR. mRNA coding for TGF-alpha (3/10), EGF (0/10), TGF-beta1 (0/10) and TGF-beta3 (2/10) or the EGF receptor (EGF-R; 0/10) and TGF-beta type-II receptor (0/10) was found only occasionally. Beta-actin was always present and positive sample controls confirmed the validity of the RT-PCR assay. These RT-PCR findings were confirmed using immunohistochemical staining of EGF and TFG-beta, whereas TGF-alpha protein was always found associated with discocytes. We conclude that the nucleus pulposus of the herniated IVD is vulnerable to proteolytic degradation and depletion of proteoglycans due to the lack and/or low production of anabolic growth factors/receptors which could increase the local synthesis of the extracellular matrix. (+info)
Medical versus surgical treatment for low back pain: evidence and clinical practice.
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CONTEXT: Although low back pain is one of the most common health problems, it is still difficult to choose between surgical and medical treatment. OBJECTIVE: To examine the evidence of the efficacy of surgical and medical treatment of the two most common indications for spinal surgery for low back pain--lumbar disc herniation and spinal stenosis--and to assess geographic variation in the use of surgery for these conditions in the United States. METHODS: The MEDLINE database (1966-1999) was searched for all studies that compared surgical and medical treatments for low back pain. Data from the Health Care Financing Administration were used to examine geographic variation in spinal surgery rates for patients enrolled in Medicare (1996-1997). RESULTS: Eight observational studies and one randomized clinical trial were identified. In general, these studies suggest better short-term outcomes (e.g., functional status and employability) with surgery than with medical approaches, but they indicate that long-term results are similar with both types of treatment. Methodologic flaws in the observational studies, particularly selection bias, preclude definitive conclusions about relative efficacy. In 1996 and 1997, more than 98,000 Medicare enrollees had surgery for disc herniation or spinal stenosis. Among hospital referral regions, rates of surgery for disc herniation varied 8-fold, from 0.24 to 1.96 per 1000 Medicare enrollees, and rates of surgery for spinal stenosis varied 12-fold, from 0.29 to 3.34 per 1000 Medicare enrollees. CONCLUSIONS: The literature comparing the efficacy of surgical and medical treatment for low back pain is limited. Not surprisingly, the use of surgery for low back pain varies widely across the United States. To establish clinical consensus, we need better evidence about the efficacy of surgery. (+info)
Matrix metalloproteinase-3-dependent generation of a macrophage chemoattractant in a model of herniated disc resorption.
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Herniated disc (HD) is a common health problem that is resolved by surgery unless spontaneous resorption occurs. HD tissue contains abundant macrophage infiltration and high levels of matrix metalloproteinases (MMPs) MMP-3 and MMP-7. We developed a model system in which disc tissue or isolated chondrocytes from wild-type or MMP-null mice were cocultured with peritoneal macrophages and used this system to investigate the role of MMPs and chondrocyte/macrophage interactions in disc resorption. We observed a marked enhancement of MMP-3 protein and mRNA in chondrocytes after exposure to macrophages. Chondrocytic MMP-3, but not MMP-7, was required for disc resorption, as determined by assaying for a reduction in wet weight and proteoglycan content after 3 days of coculture. Surprisingly, chondrocyte MMP-3 was required for the generation of a macrophage chemoattractant and the subsequent infiltration of the disc tissue by proteolytically active macrophages. We conclude that macrophage induction of chondrocyte MMP-3 plays a major role in disc resorption by mechanisms that include the generation of a bioactive macrophage chemoattractant. (+info)