-
Hand Surgery & Rehabilitation Feb 2020The median nerve is a mixed sensory and motor nerve. It is classically described as the nerve of pronation, of thumb, index finger, middle finger and wrist flexion, of... (Review)
Review
The median nerve is a mixed sensory and motor nerve. It is classically described as the nerve of pronation, of thumb, index finger, middle finger and wrist flexion, of thumb antepulsion and opposition, as well as the nerve of sensation for the palmar aspect of the first three fingers. It takes its name from its middle position at the end of the brachial plexus and the forearm. During its course from its origin at the brachial plexus to its terminal branches, it runs through various narrow passages where it could be compressed, such as the carpal tunnel or the pronator teres. The objective of this review is to summarize the current knowledge on the median nerve's anatomy: anatomical variations (branches, median-ulnar communicating branches), fascicular microanatomy, vascularization, anatomy of compression sites, embryology, ultrasonographic anatomy. The links between its anatomy and clinical, surgical or diagnostic applications are emphasized throughout this review.
Topics: Central Nervous System; Efferent Pathways; Fascia; Hand; Humans; Humeral Fractures; Median Nerve; Median Neuropathy; Nerve Compression Syndromes; Nerve Endings; Neurologic Examination; Neurons; Peripheral Nerve Injuries; Spinal Nerves; Upper Extremity
PubMed: 31816428
DOI: 10.1016/j.hansur.2019.10.197 -
International Journal of Molecular... Feb 2020Degenerative disc disease is a leading cause of chronic back pain in the aging population in the world. Sinuvertebral nerve and basivertebral nerve are postulated to be... (Review)
Review
Lumbar Degenerative Disease Part 1: Anatomy and Pathophysiology of Intervertebral Discogenic Pain and Radiofrequency Ablation of Basivertebral and Sinuvertebral Nerve Treatment for Chronic Discogenic Back Pain: A Prospective Case Series and Review of Literature.
Degenerative disc disease is a leading cause of chronic back pain in the aging population in the world. Sinuvertebral nerve and basivertebral nerve are postulated to be associated with the pain pathway as a result of neurotization. Our goal is to perform a prospective study using radiofrequency ablation on sinuvertebral nerve and basivertebral nerve; evaluating its short and long term effect on pain score, disability score and patients' outcome. A review in literature is done on the pathoanatomy, pathophysiology and pain generation pathway in degenerative disc disease and chronic back pain. 30 patients with 38 levels of intervertebral disc presented with discogenic back pain with bulging degenerative intervertebral disc or spinal stenosis underwent Uniportal Full Endoscopic Radiofrequency Ablation application through either Transforaminal or Interlaminar Endoscopic Approaches. Their preoperative characteristics are recorded and prospective data was collected for Visualized Analogue Scale, Oswestry Disability Index and MacNab Criteria for pain were evaluated. There was statistically significant Visual Analogue Scale improvement from preoperative state at post-operative 1wk, 6 months and final follow up were 4.4 ± 1.0, 5.5 ± 1.2 and 5.7 ± 1.3, respectively, < 0.0001. Oswestery Disability Index improvement from preoperative state at 1week, 6 months and final follow up were 45.8 ± 8.7, 50.4 ± 8.2 and 52.7 ± 10.3, < 0.0001. MacNab criteria showed excellent outcomes in 17 cases, good outcomes in 11 cases and fair outcomes in 2 cases Sinuvertebral Nerve and Basivertebral Nerve Radiofrequency Ablation is effective in improving the patients' pain, disability status and patient outcome in our study.
Topics: Adolescent; Adult; Aged; Back Pain; Catheter Ablation; Chronic Pain; Female; Humans; Intervertebral Disc Degeneration; Lumbar Vertebrae; Male; Middle Aged; Prospective Studies; Spinal Nerves
PubMed: 32098249
DOI: 10.3390/ijms21041483 -
Journal of Back and Musculoskeletal... 2022First discussed by Dr. Robert Maigne in the late 1980s, Maigne Syndrome is an often unrecognized and treatable cause of low back pain. It can be separated into two... (Review)
Review
BACKGROUND
First discussed by Dr. Robert Maigne in the late 1980s, Maigne Syndrome is an often unrecognized and treatable cause of low back pain. It can be separated into two distinct entities. The central variant is a result of nerve afferent input secondary to changes of facet joint arthropathy at the thoracolumbar junction. The peripheral variant is a result of impingement of the medial branch of the superior cluneal nerve, which arises from the posterior rami of the lower thoracic and upper lumbar nerve roots, and results in similar clinical symptoms and signs.
OBJECTIVE
To review the current literature for a comprehensive description of Maigne Syndrome, its diagnosis and management.
METHODS
Evidence was gathered using two main medical databases, namely PubMed and Google Scholar. Search terms included 'Maigne's Syndrome', 'Maigne facet', 'thoracolumbar junction syndrome', 'cluneal nerve entrapment', 'posterior iliac crest trigger point', 'pseudosciatica', as well as various permutations of these terms.
RESULTS
The initial search generated 52 articles. These were screened, and duplicate and irrelevant articles were removed. Using the remaining articles, and with evaluation of their cited references, we selected 28 articles for review. Most of these consisted of case reports, many of which were published in rehabilitation, chiropractic and medical journals. The papers explored topics such as anatomy, cluneal nerve imaging, and treatment of nerve entrapment and facet related back pain syndromes, and have been included in this review, which is, to the best our knowledge, the most comprehensive description of Maigne Syndrome to date.
CONCLUSION
The keys to the diagnosis of Maigne Syndrome include an awareness of the mechanical causes of back dominant pain, an understanding of the relevant anatomy, a specific clinical examination, and focused radiological guided anesthetic blocks. Treatment is available, and as in all back-pain etiologies, is most effective in the early stages of the disease.
Topics: Humans; Ilium; Low Back Pain; Lumbosacral Region; Nerve Compression Syndromes; Spinal Nerves
PubMed: 34151827
DOI: 10.3233/BMR-200297 -
Neuron Oct 2020Primary somatosensory neurons are specialized to transmit specific types of sensory information through differences in cell size, myelination, and the expression of...
Primary somatosensory neurons are specialized to transmit specific types of sensory information through differences in cell size, myelination, and the expression of distinct receptors and ion channels, which together define their transcriptional and functional identity. By profiling sensory ganglia at single-cell resolution, we find that all somatosensory neuronal subtypes undergo a similar transcriptional response to peripheral nerve injury that both promotes axonal regeneration and suppresses cell identity. This transcriptional reprogramming, which is not observed in non-neuronal cells, resolves over a similar time course as target reinnervation and is associated with the restoration of original cell identity. Injury-induced transcriptional reprogramming requires ATF3, a transcription factor that is induced rapidly after injury and necessary for axonal regeneration and functional recovery. Our findings suggest that transcription factors induced early after peripheral nerve injury confer the cellular plasticity required for sensory neurons to transform into a regenerative state.
Topics: Activating Transcription Factor 3; Animals; Axons; Axotomy; Cellular Reprogramming; Crush Injuries; Ganglia, Spinal; Gene Expression Regulation; Lumbar Vertebrae; Mechanoreceptors; Mice; Nerve Regeneration; Neuralgia; Neuronal Plasticity; Nociceptors; Peripheral Nerve Injuries; RNA-Seq; Recovery of Function; Sciatic Nerve; Sensory Receptor Cells; Single-Cell Analysis; Spinal Nerves; Transcriptome
PubMed: 32810432
DOI: 10.1016/j.neuron.2020.07.026 -
Pain Physician Jul 2022The superior and middle cluneal nerves are sources of low back, buttock, and leg pain. These nerves are cutaneous branches of the lateral branches of the dorsal rami of... (Review)
Review
BACKGROUND
The superior and middle cluneal nerves are sources of low back, buttock, and leg pain. These nerves are cutaneous branches of the lateral branches of the dorsal rami of T11- S4. Pain arising from entrapment or dysfunction of one or more of these nerves is called "cluneal nerve syndrome." A clear understanding of the anatomy underlying cluneal nerve syndrome and its treatment has been hampered by the very small size of the cluneal nerves and their complex, varying anatomy. Because of differing methods and foci of investigation, the literature regarding cluneal nerves has been confusing and even contradictory.
OBJECTIVES
This paper provides a thorough critical literature review of cluneal nerve anatomy and implications for therapy.
STUDY DESIGN
A modified scoping review.
METHODS
The bibliographic trail of English language papers on the anatomy and treatment of cluneal nerve syndrome was used to resolve the contradictions that have appeared in some of the anatomic descriptions and, where applicable, to examine their implications for therapy.
RESULTS
Recent anatomic and surgical investigations confirm a wider than previously realized range of central nervous system origins of these peripheral nerves, explaining why cluneal nerve dysfunction can cause a wide array of symptoms, including low back, buttock, and/or leg pain or "pseudosciatica."
CONCLUSIONS
Cluneal nerve syndrome is characterized by a triad of pain, tender points, and relief with local anesthetic injections. The pain is a deep, aching, poorly localized low back pain with variable involvement of the buttocks and/or legs. Tender points are localized at the iliac crest or caudal to the posterior superior iliac spine. Muscle weakness and dermatomal sensory changes are absent in cluneal nerve syndrome. If the pain returns after injections, neuroablation, nerve stimulation, or surgical release may be needed.
Topics: Buttocks; Humans; Ilium; Low Back Pain; Nerve Compression Syndromes; Spinal Nerves
PubMed: 35793175
DOI: No ID Found -
International Journal of Radiation... Jan 2022To present interobserver variability in thecal sac (TS) delineation based on contours generated by 8 radiation oncologists experienced in spine stereotactic body...
Thecal Sac Contouring as a Surrogate for the Cauda Equina and Intracanal Spinal Nerve Roots for Spine Stereotactic Body Radiation Therapy (SBRT): Contour Variability and Recommendations for Safe Practice.
PURPOSE
To present interobserver variability in thecal sac (TS) delineation based on contours generated by 8 radiation oncologists experienced in spine stereotactic body radiation therapy and to propose contouring recommendations to standardize practice.
METHODS AND MATERIALS
In the setting of a larger contouring study that reported target volume delineation guidelines specific to sacral metastases, 8 academically based radiation oncologists with dedicated spine stereotactic body radiation therapy programs independently contoured the TS as a surrogate for the cauda equina and intracanal spinal nerve roots. Uniform treatment planning simulation computed tomography datasets fused with T1, T2, and T1 post gadolinium magnetic resonance imaging for each case were distributed to each radiation oncologist. All contours were analyzed and agreement was calculated using both Dice similarity coefficient and simultaneous truth and performance level estimation with kappa statistics.
RESULTS
A fair level of simultaneous truth and performance level estimation agreement was observed between practitioners, with a mean kappa agreement of 0.38 (range, 0.210.55) and the mean Dice similarity coefficient (± standard deviation, with range) was 0.43 (0.36 ± 0.1 to -0.53 ±0.1). Recommendations for a reference TS contour, accounting for the variations in practice observed in this study, include contouring the TS to encompass all the intrathecal spinal nerve roots, and caudal to the termination of the TS, the bony canal can be contoured as a surrogate for the extra thecal nerves roots that run within it.
CONCLUSIONS
This study shows that even among high-volume practitioners, there is a lack of uniformity when contouring the TS. Further modifications may be required once dosimetric data on nerve tolerance to ablative doses, and pattern of failure analyses of clinical data sets using these recommendations, become available. The contouring recommendations were designed as a guide to enable consistent and safe contouring across general practice.
Topics: Cauda Equina; Humans; Magnetic Resonance Imaging; Radiosurgery; Radiotherapy Planning, Computer-Assisted; Sacrum; Spinal Nerve Roots
PubMed: 34454046
DOI: 10.1016/j.ijrobp.2021.08.023 -
Brain, Behavior, and Immunity Feb 2021Microglia play an important role in the central sensitization and chronic pain. However, a direct connection between microglial function and pain development in vivo...
Microglia play an important role in the central sensitization and chronic pain. However, a direct connection between microglial function and pain development in vivo remains incompletely understood. To address this issue, we applied chemogenetic approach by using CXCR1:R26 transgenic mice to enable expression of inhibitory Designer Receptors Exclusively Activated by Designer Drugs (Gi DREADD) in microglia. We found that microglial Gi DREADD activation inhibited spinal nerve transection (SNT)-induced microglial reactivity as well as chronic pain in both male and female mice. Gi DREADD activation downregulated the transcription factor interferon regulatory factor 8 (IRF8) and its downstream target pro-inflammatory cytokine interleukin 1 beta (IL-1β). Using in vivo spinal cord recording, we found that activation of microglial Gi DREADD attenuated synaptic transmission following SNT. Our results demonstrate that microglial Gi DREADD reduces neuroinflammation, synaptic function and neuropathic pain after SNT. Thus, chemogenetic approaches provide a potential opportunity for interrogating microglial function and neuropathic pain treatment.
Topics: Animals; Chronic Pain; Female; Male; Mice; Microglia; Neuralgia; Spinal Cord; Spinal Nerves
PubMed: 33221486
DOI: 10.1016/j.bbi.2020.11.030 -
Neuroscience Bulletin Mar 2021Chemokines and receptors have been implicated in the pathogenesis of chronic pain. Here, we report that spinal nerve ligation (SNL) increased CXCR3 expression in dorsal...
Chemokines and receptors have been implicated in the pathogenesis of chronic pain. Here, we report that spinal nerve ligation (SNL) increased CXCR3 expression in dorsal root ganglion (DRG) neurons, and intra-DRG injection of Cxcr3 shRNA attenuated the SNL-induced mechanical allodynia and heat hyperalgesia. SNL also increased the mRNA levels of CXCL9, CXCL10, and CXCL11, whereas only CXCL10 increased the number of action potentials (APs) in DRG neurons. Furthermore, in Cxcr3 mice, CXCL10 did not increase the number of APs, and the SNL-induced increase of the numbers of APs in DRG neurons was reduced. Finally, CXCL10 induced the activation of p38 and ERK in ND7-23 neuronal cells and DRG neurons. Pretreatment of DRG neurons with the P38 inhibitor SB203580 decreased the number of APs induced by CXCL10. Our data indicate that CXCR3, activated by CXCL10, mediates p38 and ERK activation in DRG neurons and enhances neuronal excitability, which contributes to the maintenance of neuropathic pain.
Topics: Animals; Ganglia, Spinal; Hyperalgesia; Mice; Neuralgia; Rats; Rats, Sprague-Dawley; Spinal Nerves
PubMed: 33196963
DOI: 10.1007/s12264-020-00608-1 -
Handbook of Clinical Neurology 2021The arterial supply of the spinal cord is provided by the spinal branch of the cervical, thoracic, and lumbar intersegmental arteries. While supply is initially provided... (Review)
Review
The arterial supply of the spinal cord is provided by the spinal branch of the cervical, thoracic, and lumbar intersegmental arteries. While supply is initially provided at each embryonic segment, only a few prominent anterior radiculomedullary arteries remain at the adult stage, including the arteries of the cervical and lumbosacral enlargements as well as a constant upper thoracic contributor. The spinal cord is surrounded by the vasocorona, an arterial network that includes several longitudinal anastomotic chains, notably the anterior and posterior spinal arteries, which respectively supply the central and peripheral components of the intrinsic vascularization. The intrinsic venous circulation is also divided into central and peripheral components. The perimedullary venous system includes several longitudinal anastomotic chains interconnected by the coronary plexus. The radiculomedullary veins loosely follow the spinal nerve roots on their way to the epidural plexus. Their point of passage through the thecal sac forms an important valve-like structure, the antireflux mechanism.
Topics: Epidural Space; Head; Humans; Spinal Cord; Spinal Nerve Roots; Vertebral Artery
PubMed: 33272403
DOI: 10.1016/B978-0-444-64034-5.00007-9 -
Neuron Jan 2022Spontaneous pain refers to pain occurring without external stimuli. It is a primary complaint in chronic pain conditions and remains difficult to treat. Moreover, the...
Spontaneous pain refers to pain occurring without external stimuli. It is a primary complaint in chronic pain conditions and remains difficult to treat. Moreover, the mechanisms underlying spontaneous pain remain poorly understood. Here we employed in vivo imaging of dorsal root ganglion (DRG) neurons and discovered a distinct form of abnormal spontaneous activity following peripheral nerve injury: clusters of adjacent DRG neurons firing synchronously and sporadically. The level of cluster firing correlated directly with nerve injury-induced spontaneous pain behaviors. Furthermore, we demonstrated that cluster firing is triggered by activity of sympathetic nerves, which sprout into DRGs after injury, and identified norepinephrine as a key neurotransmitter mediating this unique firing. Chemogenetic and pharmacological manipulations of sympathetic activity and norepinephrine receptors suggest that they are necessary and sufficient for DRG cluster firing and spontaneous pain behavior. Therefore, blocking sympathetically mediated cluster firing may be a new paradigm for treating spontaneous pain.
Topics: Ganglia, Spinal; Humans; Pain; Sensory Receptor Cells; Spinal Nerves; Sympathetic Nervous System
PubMed: 34752775
DOI: 10.1016/j.neuron.2021.10.019