Mechanical Compression Of Nerve Roots Research Articles

Effects of Multimodal Physical Therapy on Pain, Disability, H-reflex, and Diffusion Tensor Imaging Parameters in Patients With Lumbosacral Radiculopathy Due to Lumbar Disc Herniation: A Preliminary Trial.

Background Lumbosacral radiculopathy (LSR) due to lumbar disc herniation (LDH) is a condition caused by mechanical compression of nerve roots. Various physical therapy interventions have been proposed for the conservative management of LSR due to LDH. However, the study of physical therapy interventions in a multimodal form is lacking. Additionally, the effect of physical therapy on diffusion tensor imaging (DTI) parameters of the compressed nerve root has not been studied. This study aimed to investigate the effects of multimodal physical therapy (MPT) on pain, disability, soleus H-reflex, and DTI parameters of the compressed nerve root in patients with chronic unilateral LSR due to LDH. Methods A prospective preliminary pre-postclinical trial with a convenience sample was conducted. A total of 14 patients with chronic unilateral LSR due to paracentral L4-L5 or L5-S1 LDH were recruited for the study. Participants received a total of 18 sessions of a six-weekMPT program that consisted of electrophysical agents, manual therapy interventions, and core stability exercises. Electrophysical agents involved interferential current and hot pack. Manual therapy interventions included myofascial release, side posture positional distraction, passive spinal rotation mobilization, and high-velocity low-amplitude manipulation. Visual analog scale (VAS), Roland-Morris Disability Questionnaire (RMDQ), soleus H-reflex amplitude, side-to-side amplitude (H/H) ratio, fractional anisotropy (FA), and apparent diffusion coefficient (ADC) of the compressed nerve root were measured at baseline and post-intervention. Results There were significant improvements in VAS, RMDQ, H/H ratio, FA, and ADC of the compressed nerve root. Furthermore,significant improvement was found in the affected side compared with the contralateral side in H-reflex amplitude. Conclusions The observations of this preliminary trial suggest that MPT is a successful intervention in patients with chronic unilateral LSR due to LDH. Regarding DTI parameters of the compressed nerve root, FA increased and ADC decreased. Future studies with a control group, large sample sizes, and longer follow-up periods are needed.

SANOGENESIS OF PAIN SYNDROMES CAUSED BY DEGENERATIVE-DYSTROPHIC SPINE DAMAGE

Aim. Explore different treatment approaches for degenerative-dystrophic damage of the spine and formulate the most effective treatment methods, their stage from accounting pathogenetic basis of pain syndromes.
 Research methods – bibliosemantic, comparative, systemic.
 Results. Diverse treatments for degenerative-dystrophic damage of the spine does not facilitate but even complicates general practitioner’s work due to the fact that information on clinical benefits of various drugs and techniques as well as various types of surgery is too contradictory; there is no single method of consistent, combination therapy for vertebrogenic pain. There is no universal therapy or surgery that would provide sustainable relief of symptoms of nonspecific back pain and/or radicular syndrome. The pathogenesis of development of specific clinical manifestations of the disease and the ratio of clinical manifestations and pathomorphological changes are crucial in choosing the treatment. The general principles of treatment are unchanged: rest, analgesics and movement should be combined in appropriate sanogenic proportions in each case. Reduction of oedema and swelling of the intervertebral disc and the spinal nerve root, nerve endings are crucial in regression of pain syndrome. There is no doubt that nonsteroidal anti-inflammatory drugs (NSAIDs) are the most effective in relieving lumbar and radicular pain at the beginning of treatment. In the absence of significant improvement after the use of NSAIDs and the necessary sanogenic motor loads, a more dynamic treatment should be used. First of all, different methods of local administration of pharmacological drugs: starting with the banal subcutaneous injection of painful areas and finishing with ultrasound and MRI-controlled injections directly into the area around the damaged nerve root, the epidural space, or the facet joint. In most cases, epidural injections can reach areas of disc-radicular conflict – after the drug is injected into the epidural space, favourable conditions are created for diffusion of glucocorticoids (or other pharmacological agents) into surrounding tissues, as well as the nerve root, regardless of its compression or irritation.
 Conclusions. And only after the ineffectiveness of NSAIDs and puncture treatments, as well as epidural injection and in the case of persistent mechanical compression of nerve roots in comparison with clinical manifestations, appropriate surgical treatments, both minimally invasive and open, are necessary.

A double-network hydrogel for the dynamic compression of the lumbar nerve root.

Current animal models of nerve root compression due to lumbar disc herniation only assess the mechanical compression of nerve roots and the inflammatory response. Moreover, the pressure applied in these models is static, meaning that the nerve root cannot be dynamically compressed. This is very different from the pathogenesis of lumbar disc herniation. In this study, a chitosan/polyacrylamide double-network hydrogel was prepared by a simple two-step method. The swelling ratio of the double-network hydrogel increased with prolonged time, reaching 140. The compressive strength and compressive modulus of the hydrogel reached 53.6 and 0.34 MPa, respectively. Scanning electron microscopy revealed the hydrogel's crosslinked structure with many interconnecting pores. An MTT assay demonstrated that the number of viable cells in contact with the hydrogel extracts did not significantly change relative to the control surface. Thus, the hydrogel had good biocompatibility. Finally, the double-network hydrogel was used to compress the L4 nerve root of male sand rats to simulate lumbar disc herniation nerve root compression. The hydrogel remained in its original position after compression, and swelled with increasing time. Edema appeared around the nerve root and disappeared 3 weeks after operation. This chitosan/polyacrylamide double-network hydrogel has potential as a new implant material for animal models of lumbar nerve root compression. All animal experiments were approved by the Animal Ethics Committee of Neurosurgical Institute of Beijing, Capital Medical University, China (approval No. 201601006) on July 29, 2016.

Value of 3D MR Lumbosacral Radiculography in the Diagnosis of Symptomatic Chemical Radiculitis

Radiologic methods for the diagnosis of chemical radiculitis associated with anular tears in the lumbar spine have been rare. Provocative diskography is one of the methods for diagnosing diskogenic chemical radiculitis but is invasive. A reliable imaging method for replacing provocative diskography and diagnosing chemical radiculitis is required. Our aim was to investigate the value of 3D MR radiculography depicted by rendering imaging in the diagnosis of symptomatic chemical radiculopathy associated with anular tears. The study population consisted of 17 patients (age range, 32-88 years) with unilateral radiculopathy. Symptomatic chemical radiculopathy was confirmed with provocative CT diskography and/or provocative selective nerve root block for agreement of sides and levels. Through adhering to the principles of selective excitation (Proset imaging), we acquired 3D coronal FFE sequences with selective water excitation. Morphologic changes in the ipsilateral symptomatic nerve root caused by chemical radiculopathy were compared with those in the contralateral nerve root on 3D MR lumbosacral radiculography. Pain reproduction at the contrast-leak level during diskography (n = 4) and selective nerve root injection (n = 13) showed concordant pain in all patients. All patients with symptomatic chemical radiculopathy showed nerve root swelling in both ipsilateral levels and sides on 3D MR radiculography. The most common nerve root affected by the chemical radiculopathy was the L5 nerve root (n = 13), while the most common segment exhibiting nerve root swelling was the exit nerve root (n = 16). All patients with radicular leg pain caused by chemical radiculopathy showed nerve root swelling on 3D MR radiculography. We believe that in cases without mechanical nerve root compression caused by disk herniation or stenosis in the lumbar spine, nerve root swelling on 3D MR radiculography in patients with radiculopathy associated with an anular tear may be relevant in the diagnosis of symptomatic chemical radiculopathy.

Conservative Management of Perineural Cysts

A case series and literature review are presented. To review relevant data for the management of perineural cysts, and present a case series of 2 patient with symptomatic perineural cysts treated by steroid therapy. Perineural cysts are usually an incidental finding, but rarely may cause mechanical nerve root compression. Surgical treatments for perineural cysts are complicated by postoperative pseudomeningocoele and intracranial hypotension, and reoccurrence of the cyst. There are no reported nonsurgical treatments for perineural cysts. We present a case series symptomatic perineural cysts. Patients with lumbar and cervical perineural cysts were treated successfully with oral and epidural steroid therapy. Steroid therapy may offer a nonsurgical alternative for the treatment of symptomatic perineural cysts.

Motor Neuron Involvement in Experimental Lumbar Nerve Root Compression

The aim of this study is to investigate changes in lumbar motor neurons induced by mechanical nerve root compression using an in vivo model. This study is to investigate the changes of lumbar motor neuron induced by mechanical nerve root compression using in vivo model. The effect of axonal flow disturbance induced by nerve root compression was determined in lumbar motor neuron. The lumbar motor neuron should not be overlooked when considering the mechanism of weakness, so it is important to understand the morphologic and functional changes that occur in motor neurons of the spinal cord as a result of nerve root compression. However, few studies have looked at changes of neurons within the caused by disturbance of axonal flow, the axon reaction, chromatolysis, and cell death as a result of mechanical compression of the ventral root. In mongrel dogs, the seventh lumbar nerve root was compressed for 1 week, or 3 weeks using a clip. Morphologic changes of the motor neurons secondary to the axon reaction were examined by light and electron microscopy. Light and electron microscopy showed central chromatolysis of motor neurons in the lumbar cord from 1 week after the start of compression. After 3 weeks, some neurons undergoing apoptosis were seen in the ventral horn. It is important to be aware that, in patients with nerve root compression due to lumbar disc herniation or lumbar canal stenosis, dysfunction is not confined to degeneration at the site of compression but also extends to the motor neurons within the lumbar cord as a result of the axon reaction. Patients with weakness of lower leg should therefore be fully informed of the fact that these symptoms will not resolve immediately after surgery.

Intraoperative Measurements of Nerve Root Blood Flow During Discectomy for Lumbar Disc Herniation

Nerve root blood flow was intraoperatively measured before and after discectomy for lumbar disc herniation and compared with clinical features. To investigate the relation between nerve root blood flow changes and symptoms associated with lumbar disc herniation. Several authors have reported that recovery of intraneural blood flow, which restores the supply of oxygen and other nutrients to the nerve tissue, is strongly related to the rapid improvement of nerve function after discectomy for lumbar disc herniation. However, no previous study has quantitatively assessed blood flow in the human nerve root. Nerve root blood flow was monitored in 21 patients with lumbar disc herniation using laser Doppler flowmetry (ALF 21 N; ADVANCE, Tokyo, Japan) during discectomy. Possible correlations were investigated between the blood flow rates and the following clinical features: age, duration of sciatica, presence or absence of neurologic deficits, latency to pain relief, and morphology of herniated discs. The blood flow rate in 16 patients who reported immediate relief after discectomy was much greater than in 5 patients whose pain was not relieved immediately after surgery (141% 8%, = 0.0364). The increase in the blood flow rate after discectomy was five times greater in patients with neurologic deficits than in patients without neurologic deficits (158% 36%, = 0.0638). The results of the current study suggest that immediate relief from pain and resolution of neurologic deficits soon after surgery are the result of early recovery from nerve root ischemia after discectomy, and that ischemia caused by mechanical nerve root compression is mainly related to the mechanisms underlying sciatic pain production and neurologic deficits.

Exhausting fatigue influences F-wave and peripheral conduction velocity, following lumbar radiculopathy

Purpose : The purpose of the study was to determine whether mechanical nerve root compression could indirectly contribute to early muscle fatigue because of impaired activation. Method : The patients' two legs and the control group's dominant leg were subjected to exhausting foot dorsiflexion against 2 kg weight. Electrophysiological parameters were measured under three conditions: before, upon completion of, and five minutes after the exhausting effort (i.e. causing unbearable fatigue). The study was performed in a warm room (24°C), in the EMG laboratory of a rehabilitation centre using standard equipment. Eighteen patients participated in the study (12 males and six females, mean age 47.8 - 12.0 years). They suffered from lumbar radiculopathy and unilateral complaints at the L4, L5 innervation territory. There were 22 matched controls (18 males and 4 females, mean age 44.4 - 9.9 years) that were healthy subjects. The patients' two legs and the dominant leg of the control participants were tested. The peroneal nerve was stimulated supra-maximally, behind the fibular head. Recording the activity of the anterior tibial muscle served to calculate F-wave latency, the conduction velocity of the nerve and muscle complex (NMCV), the compound muscle action potential (CMAP) amplitude and the exhaustion time. Results : Following the exhausting fatigue, the symptomatic, asymptomatic, and control legs exhibited a significant decrease in NMCV and reduced CMAP amplitude ( p < 0.05). In each condition (rest, effort, recovery), the patients' two leg types exhibited similar NMCV (symptomatic vs asymptomatic), yet each of these two types was significantly slower than the controls' NMCV. A significant prolongation of F-wave latency after an exhausting effort was found in the symptomatic legs. Conclusions : Our results suggest that a continuous exhausting effort impairs F-wave latency and NMCV, presumably by decreasing the proportion of fast conducting nerve fibres. Peroneal nerve root compression can contribute to early fatigue of the respective muscles.

Proinflammatory cytokines in cerebrospinal fluid and serum in patients with disc herniation and sciatica.

Proinflammatory cytokines have been identified in herniated intervertebral discs in humans, and such cytokines have experimentally been demonstrated to be important in the pathophysiological mechanisms of disc herniation. Cerebrospinal fluid (CSF) and serum concentrations of interleukin (IL)-1beta IL-6, IL-8, interferon (IFN)-gamma and tumour necrosis factor (TNF)-alpha were investigated using the enzyme-linked immunosorbent assay (ELISA) technique in 39 patients with lumbar disc herniation and sciatica. Pain duration and pain intensity (visual analogue scale, VAS) were recorded at inclusion, and a clinical examination was performed evaluating neurological findings. The extent of disc herniation (protrusion or extrusion/sequestration) was evaluated perioperatively. Normal concentrations of IL-1beta, IL-6, IFN-gamma and TNF-alpha were present in CSF and serum in almost all patients with lumbar disc herniation. The concentrations of IL-8 in CSF were increased in 12 out of 39 patients, and these increased levels of IL-8 correlated to a short duration of pain and to more pronounced herniation (extrusion or sequestration). No relationship between IL-8 concentrations in CSF and pain intensity, positive neurological findings or a positive straight leg-raising (SLR) test was found. The observation of increased concentrations of IL-8 in CSF in patients with a short duration of symptoms supports the concept of the initial involvement of inflammatory mechanisms after a disc herniation. The finding that most of the patients with increased concentrations of IL-8 in CSF had an extrusion or a sequestration may suggest that the increase in IL-8 is related to mechanical nerve root compression, but may also indicate a biochemical effect exerted by the herniated disc on the surrounding tissue. Further studies on the potential role of IL-8 as a biomarker for disc herniation are warranted.

Autologous Nucleus Pulposus Induces Neurophysiologic and Histologic Changes in Porcine Cauda Equina Nerve Roots

Epidural application of autologous nucleus pulposus in pigs, without mechanical nerve root compression, induced a pronounced reduction in nerve conduction velocity in the cauda equina nerve roots after 1-7 days, compared to epidural application of retroperitoneal fat in control experiments. Histologically, the nerve fiber injury was more pronounced after application of nucleus pulposus than after control tissue application. The results demonstrate that nucleus pulposus may induce nerve tissue injury by mechanisms other than mechanical compression. Such mechanisms may be based on direct biochemical effects of nucleus pulposus components on nerve fiber structure and function and microvascular changes including inflammatory reactions in the nerve roots.

Autologous Nucleus Pulposus Induces Neurophysiologic and Histologic Changes in Porcine Cauda Equina Nerve Roots

Epidural application of autologous nucleus pulposus in pigs, without mechanical nerve root compression, induced a pronounced reduction in nerve conduction velocity in the cauda equina nerve roots after 1-7 days, compared to epidural application of retroperitoneal fat in control experiments. Histologically, the nerve fiber injury was more pronounced after application of nucleus pulposus than after control tissue application. The results demonstrate that nucleus pulposus may induce nerve tissue injury by mechanisms other than mechanical compression. Such mechanisms may be based on direct biochemical effects of nucleus pulposus components on nerve fiber structure and function and microvascular changes including inflammatory reactions in the nerve roots.