Peripheral nerves are bundles of nerve fibers that exit the spinal cord individually or via two main plexuses known as the brachial plexus and the lumbosacral plexus. Peripheral nerve fibers transmit sensory and motor information between the body and the central nervous system (brain and spinal cord) through ventral and dorsal roots. Axons of motor neurons innervate muscles to produce both voluntary and involuntary movements. On the other hand, sensory axons make connections with sensory receptors in the skin to detect pain and sensation.
Stretch-related injuries, compression, and lacerations are among the three most common peripheral nerve injuries (Burnett). The severity and the amount of disruption to the internal structures of the nerve
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During this process the part of the axon distal to the site of injury begins to degenerate and break apart. The cell body increases in size, causing protein and RNA metabolism to increase assisting in the repair process. Myelin is altered into fat and phagocytized by macrophages. Since the nerve has loss of continuity the muscle will atrophy. In some severe cases, degeneration may extend proximal to the site of the lesion as well as distally. An influx of calcium into the axon is required for the sealing over process. Hours after the injury has occurred, the distal ends of the lacerated axon seal over and become inflamed with Schwan cells, fibroblasts and other growth factors allow for anterograde and retrograde axonal transport to continue for several days (Campbell). Additionally, as part of the degeneration process it has been seen that certain growth associated genes such as, growth associated protein-43 (GAP-43) mRNA, brain derived neurotropic factor (BDNF) and its receptor TrkB mRNA are elevated after injury to peripheral nervous tissue. The use of brief electrical stimulation has been shown to enhance and accelerate the expression of TrkB and BNDF thus, resulting in a positive effect on nerve regeneration (Al-majed and Geremia). Several mechanisms have been found to explain the role of electrical stimulation in promoting nerve regeneration. It is seen that electrical stimulation can employ its effects through elevating cAMP levels, expression of neurotrophic factors and regeneration-associated genes as well as having a direct impact on Schwann cells.
The part of the peripheral nervous system that carries sensory information to the CNS is designated
Studies on nerve fibers’ longitudinal growth, axons’ regeneration and structural plasticity of axons and dendrites illustrated that they are restricted to short distances and limited spatial dimensions in the CNS. Scientists recognized that neural repair required plasticity, sprouting, and regeneration, which was limited within the adult CNS. However, once adult CNS axons from multiple areas successfully regenerated into peripheral nerve grafts in the spinal cord, brain, or optic nerve, scientists discovered the key role of local tissue microenvironment in determining the extent of growth. Scientists discovered neurite growth inhibitor factors enriched in myelin such as Nogo-A, myelin proteins, MAG and OMgp, semaphorins and ephrins, and chondroitin sulphate
Muscle strength and neuromuscular control is compromised. This could develop into long-term muscle weakness and motor planning dysfunction. Transcutaneous electrical nerve stimulation (TENS) could be utilized to help control pain and improve muscle weakness related to arthrogenic muscle inhibition. Evidence shows that TENS is effective in improving maximal voluntary torque and electromyographic signals of muscles (Konishi, McNair, & Rice, 2017). Mr. Versace may benefit from TENS on quadriceps femoris muscle to minimize muscle strength deterioration
found that motor unit twitch force remains constant or is even slightly increased following chronic denervation, challenging the theory that denervated muscle cannot be re-innervated, as believed since the findings of Gutmann. (Gutmann 1948, Fu and Gordon 1995a) Compensatory enlargement through the incorporation of denervated muscle fibers into adjacent motor units, by collateral sprouting, can make up for a loss of up to 80% of motoneurons of a muscle, as motor unit expand their size 3 to 5 fold. (Gordon, Yang et al. 1993) After 6 months of denervation maximal motor unit expansion through collateral sprouting was found, even though functional recovery was poor. (Fu and Gordon 1995b) These findings demonstrate that both the reduced number of axons reaching denervated motor endplates and atrophic muscle changes, respectively, influence poor functional outcomes after nerve injury. (Fu and Gordon 1997, Furey, Midha et al.
The incidence of hoarseness was 11% after PACU discharge and lasted a mean of 2 days. The etiology of these symptoms was not formally established. It is possible that symptoms were due to prolonged block of the phrenic and recurrent laryngeal nerves. (Liu et al, 2010).
The nerve did not likely have a complete laceration, but rather her post-surgical issues may have been a result of a stretching injury or adjacent soft tissue swelling which could resolve
The CNS contains the brain and spinal cord. Its main functions include: processing, integrating, and coordinating sensory information and motor instructions. The sensory data conducts information that is being processed from internal and external conditions the body is experiencing. Motor commands regulate and control peripheral organs (skeletal muscles). The brain functions under memory, emotions, learning, and intelligence. The PNS consist of the neural tissue found outside of the CNS. It functions in sending data to the CNS which motor commands are than carried out to the peripheral tissues/systems. Multiple nerve fibers send sensory data and motor commands in the PNS. The nerves that assist with transmitting data include the cranial nerves and spinal nerve. However, the PNS can be divided into afferent (to bring in) and efferent (to bring out) divisions of transferring data. The afferent division functions in bringing in sensory data to the CNS. Sensory structures are receptors that detect internal/external environmental change and adjusting accordingly. The efferent division functions in carrying out motor commands from the CNS to glands, muscles, and adipose tissue. The efferent division contains somatic
The cause of the disorder is when the spinal cord with the rest of the body. There is a peripheral nerve fiber that extend from your nerve cells into your body's periphery back toward the spinal cord. The muscle-controlling nerve cells in the spinal cord out toward the muscles. Axons transmit electrical signals for sensation and movement to and from the spinal cord.
Out of the twelve cranial nerves, I picked the optic nerve to research on how it can become damaged. Optic nerve damage would be described as any kind of injury or damage to the optic nerve, which is including trauma, inflammation, disease or deterioration. There is another name for optic nerve damage, which is called optic nerve atrophy or optic neuropathy. Optic nerve damage involves vision damage, vision loss, and blindness. Optic nerve damage can result from a various of different things. It can form from Glaucoma, or also known as high blood pressure within the eye, an infection or inflammation, interruption in blood circulation to the optic nerve, cancer, and trauma.
Evaluation of the prognosis of recovery of the nerve injury should be first established before management could be done conservatively or using a surgical approach.
The muscular system, in conjunction with the skeletal system, is responsible for movement of the body among other things (VanPutte, 270). The ability of the human body to move has been critical in the survival of the species over the years—for example; escaping from predators is only possible with skeletal muscle contraction. Hansen’s disease generally only affects the peripheral nerves of the extremities, not the locations of the larger muscle groups; however the smaller muscles of the hands and feet are vital for the well-being of individuals. For example, it would be quite difficult to feed oneself without the use of hands. Unfortunately, extreme cases of Hansen’s disease cause paralysis of the individual’s hands and feet. Paralysis occurs due to deadening of the peripheral nerves, both sensory and motor. As the afferent neurons lose the ability to receive and send stimuli, the nerve impulses (action potentials) are sent to the central nervous system less and less often. Even so, the action potentials that are transmitted to the CNS still are unlikely to stimulate the skeletal muscles for contraction. This is because the efferent peripheral neurons of the hands and feet are damaged as well. In effect, the sensory nerves of the extremities cannot receive much stimuli, and the motor neurons are also less able to start the action potentials in the skeletal muscle
It is known that following primary sensory axonal injury there is a slight increase in regeneration of their central axons, meaning that the increase in growth status after injury causes regeneration. Previous studies have looked into conditioning lesion and found that primary sensory neurons can in fact increase their growth capacity and enhance regeneration after injury, activating ciliary neurotrophic factors (CNTF), interleukin-6 (IL-6), and the cAMP signaling pathway among others in conditioning lesion. In the current article the researchers investigated whether ATP injection into peripheral nerves were able to mimic the effects of nerve injury in promoting regeneration of sensory neurons both in vivo and in vitro, so that the growth and
Based on the literature the use of indwelling electrical stimulation after injury and surgical repair is supported as a modality to promote axonal regeneration of both sensory and motor neurons in animals and humans. The stimulation protocol that is seen as being the most beneficial for axonal regeneration and functional recovery is brief, low frequency (20Hz) continuous electrical stimulation with short phase duration and between 3-5 volts. Asensio-Pinilla et al. looked that the effects of electrical stimulation combined with exercise to increase axonal regeneration. Treadmill training when combined with acute electrical stimulation was seen to enhance regeneration and increase motor nerve conduction velocity. Asensio-Pinilla et al. was able to provided
Objective: Facial nerve injury is considered as the most frequent complication of parotid gland surgery due to close relation of the extra-temporal course of facial nerve and the parotid gland. The aim of the current study was to evaluate the role of anatomical location of parotid tumors in the incidence of post-operative facial nerve paresis with antegrade dissection technique. Methods: Patients with parotid tumors required surgical procedures were enrolled in the study. Preoperative evaluation of the tumor location within the parotid gland tumor was done using axial and coronal CT. Transient facial nerve dysfunction was investigated in relation to the following factors: patient age, tumor size, histopathological diagnosis, and the location
Stretch-related injuries, compression, ischemia and lacerations are among the most common peripheral nerve injuries (Burnett). The severity and the amount of disruption to internal structures of the nerve determine the degree of injury. There are five degrees of injury that exist ranging from first to fifth degree based on the Sunderland classification system (Burnett). A first-degree injury is the least severe and a fifth-degree injury is the most severe resulting in complete transection of the nerve. The degeneration and regeneration process of peripheral nerves is depended on the degree of injury and axon length to target muscle (Campbell). Since injury by way of laceration is easily reproduced, research subjects in the literature analyzed