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Orthopaedics & Traumatology, Surgery &... Feb 2021At the elbow, the ulnar nerve (UN) may be the site of a static compression (by the cubital tunnel retinaculum and Osborne's ligament between the two heads of the flexor... (Review)
Review
At the elbow, the ulnar nerve (UN) may be the site of a static compression (by the cubital tunnel retinaculum and Osborne's ligament between the two heads of the flexor carpi ulnaris), or a dynamic compression, especially when the nerve is unstable (subluxation/dislocation outside the ulnar groove). The clinical basis for the diagnosis of ulnar neuropathy involves looking for subjective and objective signs of sensory and/or motor deficit in the ulnar nerve's territory in the hand, a pseudo-Tinel's sign, and doing manipulations to provoke UN irritation. The diagnosis is confirmed by electromyography and ultrasonography. In the early stages, patient education and elimination of flexion postures or repeated elbow flexion motions can provide relief. If this fails or signs of sensory and/or motor deficit are present, surgical treatment is proposed. If the nerve is stable, in-situ nerve decompression is typically done as the first-line treatment. If the nerve is unstable, anterior nerve transposition - generally subcutaneous - or more rarely, a medial epicondylectomy can be done. If surgical treatment fails, the patient's history is reviewed, and diagnostic tests can be repeated. Except in cases of a fibrotic scar, the main causes of failure are neuroma of a branch of the medial cutaneous nerve of the forearm, instability of the nerve and persistence of a compression point. In the latter two cases, surgical revision is justified and anterior nerve transposition or epicondylectomy can be proposed.
Topics: Cubital Tunnel Syndrome; Decompression, Surgical; Elbow; Humans; Neurosurgical Procedures; Ulnar Nerve; Ulnar Neuropathies
PubMed: 33321238
DOI: 10.1016/j.otsr.2020.102754 -
PM & R : the Journal of Injury,... May 2013Neuropathies that affect the lower limbs are often encountered after trauma or iatrogenic injury or by entrapment at areas of anatomic restriction. Symptoms may... (Review)
Review
Neuropathies that affect the lower limbs are often encountered after trauma or iatrogenic injury or by entrapment at areas of anatomic restriction. Symptoms may initially be masked by concomitant trauma or recovery from surgical procedures. The nerves that serve the lower extremities arise from the lumbosacral plexus, formed by the L2-S2 nerve roots. The major nerves that supply the lower extremities are the femoral, obturator, lateral femoral cutaneous, and the peroneal (fibular) and tibial, which arise from the sciatic nerve, and the superior and inferior gluteal nerves. An understanding of the motor and sensory functions of these nerves is critical in recognizing and localizing nerve injury. Electrodiagnostic studies are an important diagnostic tool. A well-designed electromyography study can help confirm and localize a nerve lesion, assess severity, and evaluate for other peripheral nerve lesions, such as plexopathy or radiculopathy.
Topics: Electrodiagnosis; Humans; Lower Extremity; Lumbosacral Plexus; Nerve Compression Syndromes; Risk Factors
PubMed: 23542774
DOI: 10.1016/j.pmrj.2013.03.029 -
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 -
BioMed Research International 2014Unlike other tissues in the body, peripheral nerve regeneration is slow and usually incomplete. Less than half of patients who undergo nerve repair after injury regain... (Review)
Review
Unlike other tissues in the body, peripheral nerve regeneration is slow and usually incomplete. Less than half of patients who undergo nerve repair after injury regain good to excellent motor or sensory function and current surgical techniques are similar to those described by Sunderland more than 60 years ago. Our increasing knowledge about nerve physiology and regeneration far outweighs our surgical abilities to reconstruct damaged nerves and successfully regenerate motor and sensory function. It is technically possible to reconstruct nerves at the fascicular level but not at the level of individual axons. Recent surgical options including nerve transfers demonstrate promise in improving outcomes for proximal nerve injuries and experimental molecular and bioengineering strategies are being developed to overcome biological roadblocks limiting patient recovery.
Topics: Animals; Humans; Nerve Regeneration; Peripheral Nerve Injuries; Peripheral Nerves; Plastic Surgery Procedures; Recovery of Function; Translational Research, Biomedical
PubMed: 25276813
DOI: 10.1155/2014/698256