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World Neurosurgery Mar 2020The C1 spinal nerve is a fascinating anatomic structure owing to its wide range of variations. Throughout history, understanding of the cranial and spinal nerves has... (Review)
Review
The C1 spinal nerve is a fascinating anatomic structure owing to its wide range of variations. Throughout history, understanding of the cranial and spinal nerves has probably influenced the current conception of this nerve among anatomists. Located at the craniocervical junction, the C1 spinal nerve contributes to the motor innervation of deep cervical muscles through the cervical (anterior) and Cruveilhier's (posterior) plexuses. Sensory functions of this nerve are more enigmatic; despite investigations into its dorsal rootlets, a dorsal root ganglion, and the relationships between this nerve and adjacent cranial and spinal nerves, there is still no consensus regarding its true anatomy. In this article, we review the available literature and discuss some of the developmental models that could potentially explain the wide range of variations and functions of the C1 nerve.
Topics: Cervical Plexus; Humans; Spinal Nerves
PubMed: 31838236
DOI: 10.1016/j.wneu.2019.12.024 -
Neuroreport Apr 2021Spinal cord injury (SCI) leads to permanent loss of motor and sensory function due to the complex mechanisms of the external microenvironment and internal...
Spinal cord injury (SCI) leads to permanent loss of motor and sensory function due to the complex mechanisms of the external microenvironment and internal neurobiochemistry that restrict neuronal plasticity and axonal regeneration. Chemokine CXCL12 was verified in regulating the development of central nervous system (CNS) and repairing of CNS disease. In the present study, CXCL12 was downregulated in the spinal cord after SCI. SCI also induced gliosis and loss of synapse. Intrathecal treatment of CXCL12 promoted the functional recovery of SCI by inducing the formation of neuronal connections and suppressing glia scar. To confirm whether CXCL12 promoted synapse formation and functional neuronal connections, the primary cortical neurons were treated with CXCL12 peptide, the synapse was examined using Immunofluorescence staining and the function of synapse was tested using a whole-cell patch clamp. The results indicated that CXCL12 peptide promoted axonal elongation, branche formation, dendrite generation and synaptogenesis. The electrophysiological results showed that CXCL12 peptide increased functional connections among neurons. Taken together, the present study illustrated an underlying mechanism of the development of SCI and indicated a potential approach to facilitate functional recovery of spinal cord after SCI.
Topics: Animals; Cerebral Cortex; Chemokine CXCL12; Down-Regulation; Gliosis; Nerve Regeneration; Neuronal Outgrowth; Neurons; Patch-Clamp Techniques; Rats; Real-Time Polymerase Chain Reaction; Recovery of Function; Spinal Cord Injuries; Spinal Nerves; Synapses
PubMed: 33657074
DOI: 10.1097/WNR.0000000000001613 -
Morphologie : Bulletin de L'Association... Feb 2021Since its initial description in the 2 century, the suboccipital nerve has maintained a number of varying terminologies. Many of these terms were created in the 18 and... (Review)
Review
Since its initial description in the 2 century, the suboccipital nerve has maintained a number of varying terminologies. Many of these terms were created in the 18 and 19 centuries to describe the first set of cervical spinal nerves that exited the spinal cord between the cranium and the atlas. Though the many terminologies have been reduced to mainly the suboccipital nerve, there are still two prevalent definitions used for this nerve. Herein, we discuss the history of the first spinal nerve and its branches with special attention to varying terminologies over time. Recent literature has described the suboccipital nerve as the entire nerve or as simply the dorsal ramus of the C1 spinal nerve. This interchangeability may lead to confusion about the specific part of the nerve being discussed. Following a review of the literature, we recommend the term C1 spinal nerve be applied to the entire nerve, whereas, suboccipital nerve be reserved solely for the posterior branch of the C1 spinal nerve.
Topics: Spinal Nerves
PubMed: 33172783
DOI: 10.1016/j.morpho.2020.09.002 -
Hand Surgery & Rehabilitation Feb 2022Scapula alata, also known as winged scapula, can lead to severe upper limb impairment. The shoulders' function is altered because the scapula, which supports the upper...
Scapula alata, also known as winged scapula, can lead to severe upper limb impairment. The shoulders' function is altered because the scapula, which supports the upper limb, is no longer stable. Typical scapula alata is described for serratus anterior palsy; however, any scapulothoracic muscle impairment may lead to scapular winging, particularly trapezius palsy, which is easy to miss, thus needed to be considered as a differential diagnosis. The diagnosis is difficult and based on various clinical tests and a thorough examination as well as electroneuromyography and MRI. The treatment ranges from conservative treatments for spontaneous recovery, nerve surgery including neurolysis, nerve transfers and nerve grafts for acute cases, to tendon transfers for more chronic cases and when nerve procedures are no longer feasible. Tendon transfers in serratus anterior palsy produce excellent results with a high rate of patient satisfaction and are described with the sternal or clavicular head of the pectoralis major; we describe our preferred technique in this article. Tendon transfers in trapezius palsy are performed with the levator scapulae, rhomboid minor and major muscles. Our preferred method is the Elhassan triple transfer. Scapula alata is a frequent and often misdiagnosed condition. Appropriate management can yield excellent results. Patients should be referred right away to specialized centers for surgery if recovery is not spontaneous.
Topics: Humans; Range of Motion, Articular; Scapula; Superficial Back Muscles; Tendon Transfer; Thoracic Nerves
PubMed: 34246815
DOI: 10.1016/j.hansur.2020.09.016 -
Current Sports Medicine Reports Sep 2021The painful tingling arm is a common presenting complaint for the musculoskeletal physician. The differential diagnosis for upper-extremity pain associated with... (Review)
Review
The painful tingling arm is a common presenting complaint for the musculoskeletal physician. The differential diagnosis for upper-extremity pain associated with paresthesias will be the focus of this review. Symptoms are often neurologic in etiology, originating from the spinal cord, nerve root(s), brachial plexus, or peripheral nerve(s). Localizing the pathology starts with a comprehensive understanding of neuromuscular anatomy. It also is imperative to understand the function of these respective structures. The differential diagnosis can be narrowed with a thorough history, including an assessment of sport-specific risk factors, along with a comprehensive physical examination and functional assessment. It is important to determine the sensory distribution of the patient's symptoms. If weakness also is present, the affected muscles must be identified. While the diagnosis can often be made clinically, electrodiagnostics, magnetic resonance imaging, and ultrasound can be used as needed for confirmation and more specific localization. Nonneurologic structures also may be causative or contributory to the patient's symptoms and also should be considered.
Topics: Arm; Brachial Plexus; Diagnosis, Differential; Humans; Pain; Paresthesia; Peripheral Nerves; Spinal Cord; Spinal Nerve Roots
PubMed: 34524190
DOI: 10.1249/JSR.0000000000000877 -
Toxicologic Pathology Oct 2023Biotherapeutic modalities such as cell therapies, gene therapies, nucleic acids, and proteins are increasingly investigated as disease-modifying treatments for severe...
Biotherapeutic modalities such as cell therapies, gene therapies, nucleic acids, and proteins are increasingly investigated as disease-modifying treatments for severe and life-threatening neurodegenerative disorders. Such diverse bio-derived test articles are fraught with unique and often unpredictable biological consequences, while guidance regarding nonclinical experimental design, neuropathology evaluation, and interpretation is often limited. This paper summarizes key messages offered during a half-day continuing education course on toxicologic neuropathology of neuro-targeted biotherapeutics. Topics included fundamental neurobiology concepts, pharmacology, frequent toxicological findings, and their interpretation including adversity decisions. Covered biotherapeutic classes included cell therapies, gene editing and gene therapy vectors, nucleic acids, and proteins. If agents are administered directly into the central nervous system, initial screening using hematoxylin and eosin (H&E)-stained sections of currently recommended neural organs (brain [7 levels], spinal cord [3 levels], and sciatic nerve) may need to expand to include other components (e.g., more brain levels, ganglia, and/or additional nerves) and/or special neurohistological procedures to characterize possible neural effects (e.g., cell type-specific markers for reactive glial cells). Scientists who evaluate the safety of novel biologics will find this paper to be a practical reference for preclinical safety testing and risk assessment.
Topics: Neuropathology; Brain; Spinal Cord; Sciatic Nerve; Nucleic Acids
PubMed: 38380881
DOI: 10.1177/01926233241230542 -
Folia Morphologica 2023The perforating cutaneous nerve/perforating nerve of the sacrotuberous ligament is rarely observed. It usually arises from the posterior division of the sacral plexus or...
BACKGROUND
The perforating cutaneous nerve/perforating nerve of the sacrotuberous ligament is rarely observed. It usually arises from the posterior division of the sacral plexus or the pudendal nerve and perforates the sacrotuberous ligament. The anatomy of this nerve and its variants is poorly described in the literature, but there are data indicating its role in pudendal neuralgia.
MATERIALS AND METHODS
Herein, we present an anatomical study of six formalin-fixed cadavers with descriptions of the topography of spinal nerves S2-S4, the pudendal bundle, the perforating cutaneous nerve and the sacrotuberous ligament.
RESULTS
We found three perforating cutaneous nerves and described each of them in detail, with measurements of length and width, and point of perforation of the sacrotuberous ligament.
CONCLUSIONS
We distinguished three types of perforating cutaneous nerve on the basis of our findings and previous publications; two of the three types were observed in our study.
Topics: Humans; Pudendal Nerve; Lumbosacral Plexus; Pelvis; Ligaments, Articular; Cadaver
PubMed: 35099048
DOI: 10.5603/FM.a2022.0001 -
Methods in Molecular Biology (Clifton,... 2020This chapter describes the microanatomy of the spinal cord that is relevant to intrathecal drug delivery started with covering of the spinal cord that are pierced to...
This chapter describes the microanatomy of the spinal cord that is relevant to intrathecal drug delivery started with covering of the spinal cord that are pierced to enter the intrathecal space. The dural sac is mostly constituted by the outer layer of dura and the inner layer called arachnoid membrane, which regulates diffusion of drugs into the intrathecal space. The pia matter surrounding the spinal cord is a permeable structure allowing the passage of drugs through intercellular spaces. The relationship between nerve roots, CSF, and subarachnoid catheters determines the passage of an intrathecal catheter which can cause damage to nerve roots and spinal cord. Multiple factors may be involved in the mechanisms of drug diffusion across the membranes of the spinal cord, as well as in their dilution with the CSF, which will lead to the final drug distribution and availability at nerve roots and the spinal cord.
Topics: Cerebrospinal Fluid; Diffusion; Drug Delivery Systems; Humans; Infusion Pumps, Implantable; Injections, Spinal; Spinal Cord; Spinal Nerve Roots; Subarachnoid Space
PubMed: 31435917
DOI: 10.1007/978-1-4939-9798-5_4 -
Journal of Clinical Neuroscience :... Jan 2020Occipital neuralgia typically arises in the setting of nerve compression by fibrosis, surrounding anatomic structures, or osseous pathology, such as bone spurs or... (Review)
Review
Occipital neuralgia typically arises in the setting of nerve compression by fibrosis, surrounding anatomic structures, or osseous pathology, such as bone spurs or hypertrophic atlanto-epistropic ligament. It generally presents as paroxysmal bouts of sharp pain in the sensory distribution of the first three occipital nerves. Due to the long course of the greater occipital nerve (GON), and its peculiar anatomy, and location in a mobile region of the neck, it is unsurprising that the GON is at high risk for compression. Little is known how to diagnose or treat this neuropathic pain syndrome. The objective of this paper is to isolate the etiology involved, and treat this condition promptly. After all nonoperative efforts are exhausted, surgical transection of the nerve is the treatment of choice in these cases. An isolated C2 neurectomy or ganglionectomy is performed for an optimal pain relief. C1-2 instrumented fusion can be considered if, extensive facet arthropathy with instability is identified. Authors review the spectrum of treatment options for this debilitating condition, and discuss the case example of a patient who required conversion to a C1-C2 instrumented fusion following C2 ganglionectomy due to an underlying extensive degenerative disease and intraoperative findings suggestive of atlantoaxial instability.
Topics: Aged; Denervation; Humans; Intervertebral Disc Degeneration; Joint Instability; Male; Neck Pain; Neuralgia; Ossification of Posterior Longitudinal Ligament; Spinal Fusion; Spinal Nerves; Synovial Cyst; Treatment Outcome
PubMed: 31606286
DOI: 10.1016/j.jocn.2019.08.102 -
ACS Chemical Neuroscience Dec 2022Voltage-gated sodium channels (Nas) play a crucial electrical signaling role in neurons. Na-isoforms present in peripheral sensory neurons and dorsal root ganglia of the...
Voltage-gated sodium channels (Nas) play a crucial electrical signaling role in neurons. Na-isoforms present in peripheral sensory neurons and dorsal root ganglia of the spinal cord are critically involved in pain perception and transmission. While these isoforms, particularly Na1.7, are implicated in neuropathic pain disorders, changes in the functional state and expression levels of these channels have not been extensively studied in vivo. Radiocaine, a fluorine-18 radiotracer based on the local anesthetic lidocaine, a non-selective Na blocker, has previously been used for cardiac Na1.5 imaging using positron-emission tomography (PET). In the present study, we used Radiocaine to visualize changes in neuronal Na expression after neuropathic injury. In rats that underwent unilateral spinal nerve ligation, PET/MR imaging demonstrated significantly higher uptake of Radiocaine into the injured sciatic nerve, as compared to the uninjured sciatic nerve, for up to 32 days post-surgery. Radiocaine, due to its high translational potential, may serve as a novel diagnostic tool for neuropathic pain conditions using PET imaging.
Topics: Rats; Animals; Rats, Sprague-Dawley; Spinal Nerves; Voltage-Gated Sodium Channels; Neuralgia; Ganglia, Spinal; Sensory Receptor Cells
PubMed: 36472927
DOI: 10.1021/acschemneuro.2c00717