peripheral nerve conditions Flashcards
lower motor neuron lesion
Neurons in the spinal cord that innervate muscles and glands
-they transmit signals from UMN to effector muscle to perform the movement
-has a role in somatic reflex arc (immediate spinal cord interpretation and reaction)
Caused by: injury to anterior horn cells and peripheral nerves
Risks: smoking, low BMI, risk increases with age, possible family risk
S&S: muscle atrophy, muscle twitching, decreased reflexes, decreased tone, -ve babinsky sign, flaccid paralysis
Treatment: depends on particular presenting disease
Aim= to limit symptoms
Muscle relaxants, drugs to slow down nerve cell damage, manual therapy, speech therapy, social support
radial nerve impingement
=the radial nerve becomes compressed or pinched. The radial nerve arises from C5 to C8 and provides a motor function to the extensors of the forearm, wrist, fingers, and thumb
causes: Often thought to result from overuse such as, repetitive pronation and supination of the wrist and forearm. Or secondary to other causes such as direct trauma, fractures, lacerations, compressive devices, or post-surgical changes.
patho: Compression or entrapment can occur at any location within the course of the nerve distribution, but the most frequent location of entrapment occurs in the proximal forearm.
This most common location is typically in proximity to the supinator and often will involve the posterior interosseous nerve branch. The repetitive overuse causes inflammation or architectural changes to the surrounding tissue that then compresses the nerve, There are varying degrees of nerve damage severity. In mild cases, the compression of the nerve causes no permanent damage to the nerve, and the nerve sheath fully recovers. More severe cases can cause permanent damage to the nerve and/or nerve sheath, causing persistent deficits.
risk factors: Wearing a cast or splint that is too tight, Obesity, Narrow or tight anatomical structures in the arm or wrist, such as the supinator muscle or fibrous bands, Older age, Medical conditions, such as diabetes or rheumatoid arthritis, that affect the peripheral nerves.
s&s: Presentation varies, depending on area of possible entrapment and symptoms usually develop very slowly, Pain, sensory and motor changes/weakness, paraesthesia, and/or paralysis, A positive Tinel sign along the radial aspect of the mid-forearm is suggestive of this process. Wrist flexion, ulnar deviation, and pronation place strain on the nerve and will often reproduce or exacerbate symptoms.
treatment: Rest and physical therapy: This may include exercises to stretch and strengthen the arm, wrist, and hand muscles, as well as activities to reduce swelling and inflammation, Medications: Over-the-counter pain relievers, such as ibuprofen or acetaminophen, can help reduce pain and inflammation. In some cases, prescription pain medications or anti-inflammatory drugs may be necessary, Injection therapy: Corticosteroid injections can help reduce pain and swelling in the arm and wrist, Surgery: In severe cases of radial nerve impingement, surgery may be necessary to relieve pressure on the nerve, Most people experience improvement in their symptoms within several weeks to a few months
ddx: Tennis elbow (lateral epicondylitis), Carpal tunnel syndrome, De Quervain’s tenosynovitis, Thoracic outlet syndrome, Herniated disc, Peripheral neuropathy
median nerve impingement
=too much pressure is applied to the median nerve by surrounding tissues, such as bones, cartilage, muscles or tendons.
caused by: Often thought to result from overuse such as, repetitive pronation and supination of the wrist and forearm. Or secondary to other causes such as direct trauma, fractures, lacerations, compressive devices, or post-surgical changes.
pop: more common in women. This may be because the carpal tunnel area is relatively smaller in women than in men.
risk factors: Working with vibrating tools or on an assembly line that requires prolonged or repetitive flexing of the wrist may create harmful pressure on the median nerve, Being obese, Nerve-damaging conditions. Some chronic illnesses, such as diabetes, increase the risk of nerve damage, including damage to the median nerve. Inflammatory conditions. Rheumatoid arthritis and other conditions that have an inflammatory component can affect the lining around the tendons in the wrist and put pressure on the median nerve.
s&s: Numbness or decreased sensation in the area supplied by the nerve - the thumb and index, middle or ring fingers are affected, but not the little finger, Sharp, aching or burning pain, which may radiate outward, Tingling, pins and needles sensations (paraesthesia), Muscle weakness in the affected area, Frequent feeling that hand has “fallen asleep”
treatment: Apply cold packs to reduce swelling, Wrist splinting. A splint that holds the wrist still while you sleep can help relieve night-time symptoms of tingling and numbness. Even though you only wear the splint at night, it can also help prevent daytime symptoms. Night-time splinting may be a good option if you’re pregnant because it does not involve the use of any medications to be effective, Nonsteroidal anti-inflammatory drugs (NSAIDs) to reduce swelling, Inject the carpal tunnel with a corticosteroid such as cortisone to relieve pain, Corticosteroids decrease inflammation and swelling, which relieves pressure on the median nerve. Oral corticosteroids aren’t considered as effective as corticosteroid injections for treating carpal tunnel syndrome
ddx: Ulnar or cubital tunnel syndrome, Flexor carpi radialis tenosynovitis, Cervical radiculopathy C6, Carpometacarpal arthritis of the thumb
ulnar nerve impingement
=a common peripheral nerve condition causing pain, paraesthesia and weakness in the forearm and/or 4th and 5th fingers. 2 types: Cubital Tunnel Syndrome and Guyon’s Canal Syndrome
caused by: Cubital Tunnel Syndrome–> compression of Osborne’s fascia (connects the two flexor carpi ulnaris heads (FCU) and the medial collateral ligament (MCL) of the elbow), Repetitive microtrauma - prolonged or repetitive stretching of the nerve (keeping the elbow fully flexed), direct pressure on the nerve (leaning the elbow against a solid surface), Nerve subluxation (ulnar nerve slides out from behind the medial epicondyle when the elbow is flexed, over time irritating the nerve), Olecranon bursitis, Direct trauma to the medial side of the elbow (e.g.: fracture or dislocation)
Guyon’s Canal Syndrome–> Repetitive microtrauma (often of abductor digiti minimi and the other hypothenar eminence musculature), Synovitis, Ganglion cyst, Hook of hamate fracture/displacement, Tumours, Ulnar artery thrombosis or aneurysm (causing vascular insufficiency)
s&s: Insidious onset, Aching pain or tenderness at the medial elbow (only in cubital tunnel compression), Numbness and paraesthesia in ring and little finger (especially when the elbow is bent), Weakening of grip and difficulty with finger coordination, Hypothenar eminence muscle wasting in severe and prolonged compression, Sensitivity to cold, Digital clawing (claw hand) in severe cases, Positive Tinel’s sign at cubital or ulnar tunnel, Positive Wartenberg sign, Positive Allen’s test in the case of ulnar artery thrombosis, ‘Snapping’ at medial epicondyle (may indicate ulnar nerve subluxation)
treatment: If the patient does not present with muscular atrophy: NSAIDs, Night splinting (elbow 45° flexion or wrist in neutral), Osteopathy! (Strengthen ligaments in hands and elbow)
if the patient presents with muscular atrophy or conservative treatment fails: Surgical release of Osborne’s fascia (cubital tunnel syndrome), Removal of ganglion cysts, Decompression surgery at the wrist, Surgical treatment has a nearly 100% success rate if there is no muscular atrophy (in cases with muscular atrophy, the nerve may not return to normal function)
ddx:Elbow fracture/dislocation, Hook of hamate fracture, Cervical radiculopathy (C8), Thoracic outlet syndrome, Peripheral vascular disease, Ulnar collateral ligament injury, Rheumatoid arthritis (RA), Guillain-Barré syndrome, Pancoast tumour
Musculocutaneous nerve impingement
=leaves the axilla and rapidly descends into the coracobrachialis muscle fibers
caused by: direct trauma to the musculocutaneous nerve in lacerations, gunshot wounds, and nearby bone fractures. entrapment of the musculocutaneous nerve within the coracobrachialis muscle, leading to biceps brachii and brachialis weakness and atrophy with accompanying loss of sensation in the lateral forearm, shoulder dislocation
s&s: weakness in elbow flexion or shoulder flexion, atrophy of the biceps brachii, and pain or paresthesia at the lateral forearm
treatment: Surgical decompression
axillary nerve impingement
=the axillary nerve, which supplies sensation to the shoulder and runs down the upper arm, is compressed or damaged
caused by: Traumatic injuries, traction injuries, quadrilateral space syndrome, and brachial neuritis (also called neuralgic amyotrophy or Parsonage-Turner syndrome). An anterior dislocation and forced abduction of the shoulder joint appear to be common causes of axillary nerve injury in young people.
patho: The axillary nerve is most susceptible to injury at the origin from the posterior cord, in the quadrilateral space, the anteroinferior aspect of the shoulder capsule, and within the subfascial surface of the deltoid muscle.
The repetitive overuse causes inflammation or architectural changes to the surrounding tissue that then compresses the nerve.
pop: Impingement via Anterior dislocation due to trauma more common in young people/contact sport athletes
While impingement after glenohumeral dislocation increased with age.
risk factors: Medical procedures in the axilla or surrounding area, Age, Obesity, Underlying medical conditions such as diabetes or peripheral neuropathy.
s&s: Weakness in glenohumeral abduction with or without numbness to the lateral shoulder area, May also be present with weakness in glenohumeral external rotation; however, this may not be apparent due to the ability of the infraspinatus, In patients presenting after dislocation or fracture, signs of trauma will be evident, Weakness or loss of sensation in the shoulder and upper arm, Pain or tenderness in the shoulder, upper arm, or upper back, Difficulty lifting or rotating the arm, Muscle wasting in the shoulder or upper arm, Decreased range of motion in the shoulder.
treatment: Physical therapy: exercises to improve strength and range of motion in the shoulder, Non-steroidal anti-inflammatory drugs (NSAIDs) to reduce pain and inflammation, Corticosteroid injections to reduce inflammation, Bracing or splinting to provide support and rest to the shoulder, Surgery in severe cases, such as neurolysis (decompression) or nerve repair, The prognosis for axillary nerve impingement is generally good, with most people experiencing improvement in symptoms within a few weeks to months of starting treatment.
ddx: Cervical radiculopathy, Thoracic outlet syndrome, Rotator cuff tear, Quadrilateral space syndrome, Brachial neuritis, Glenohumeral fracture/dislocation, Subacromial impingement syndrome, Herpes zoster
femoral nerve impingement
=Pinching of the femoral nerve at some point along its anatomical course
caused by: Direct injury/trauma, Prolonged pressure on the nerve, Entrapment of the nerve by muscles, joints etc. (inguinal ligament, iliopsoas tendon), Tumour or abnormal blood vessels impinging the nerve, Pathology in the spine (herniated disc, degenerative changes) impinging the nerve root, Overuse
patho: Most common form is entrapment at the spine (L2-4), as the discs bulge/prolapse backwards. This can also be from degenerative changes in the area if the spine, due to narrowing of the gaps between the vertebra impinging on the nerve root, Another form is entrapment due to a space occupying mass (tumor/abnormal growth)
pop: Any population can be effected at any time, Degenerative changes – usually 65+
risk factors: Tumours, Rheumatoid arthritis, Osteoarthritis, Disc herniation, Weight gain, Broken bones/ bone spurs, Overuse
s&s: Difficulty walking, Inability to straighten the knee/flex ankles, Pain/numbness in the legs/feet, Radiating pain from the back (L2-4) into anterior hips and legs.
treatment: Electromyography – nerve conduction study to measure signals being sent, MRI/X-Rays – to look for broken bones, tumours, and muscle damage, Neuromuscular ultrasound – check for inflammation, tumours and nerve damage, Nerve block – inject snathetuc around the nerve to temporarily stop the pain, NSAIDs and steroid injections to reduce inflammation and pain, Physical therapy, splints, casts to support the limb, Surgical intervention to remove a mass or replace a damaged nerve
ddx: Endometriosis/gynaecological problems, Pregnancy/childbirth – causing -reassure on the pelvis, Severe/prolonged muscle dysfunction, Tumours/cysts, Disc herniation
obturator nerve impingement
=when the obturator nerve (supplies adductors and obturators) becomes trapped as it passes through the inner thigh by the surrounding muscles and tissues
caused by: the nerve becoming adhered to the muscles and tissues of the inner thigh, it being stretched during certain surgery’s, becoming entrapped when exiting the obturator canal or compression due to surrounding tissue injury
pregnancy (can compress it), trauma like car accidents, surgery to abdomen
s&s: pain and paraesthesia in hip inner thigh and knee, pain moving and decreased ROM, hard to walk, leg weakness, hard to adduct hip, weakness, wasting of muscles in medial thigh, abnormal hip abduction meaning wider based gait, loss of sensation in mid and lower inner thigh, ipsilateral loss of hip adductor tendon reflex
treatment: need treatment either physical therapy or surgery depending on how severe can take different times to heal
sciatic nerve impingement
=Sciatic nerve impingement (commonly known as sciatica) can be defined as the irritation, inflammation, pinching or compression of the sciatic nerve
caused by: Bulging/ herniated disc (90% of sciatica is a herniated disc in the lumbar spine), lumbar spine stenosis, spondylolisthesis, trauma resulting in spinal cord injuries, piriformis syndrome, spinal tumour
patho: A pathology anywhere along sciatic nerve; depends on cause.
First order neurons may increase their firing if they are partially damaged and increase the number of sodium channels.
Ectopic discharges are a result of enhanced depolarization at certain sites in the fibre, leading to spontaneous pain and movement-related pain. Inhibitory circuits may be impaired at the level of the dorsal horn or brain stem (or both) allowing pain impulses to travel unopposed.
pop: No gender predominance, Patients in their 40’s, Occupational predisposition (physically awkward positions e.g., truck driver)
risk factors: age (age related changes in spine such as herniated disc and bony spurs), obesity (creates stress on spine), prolonged sitting, diabetes (increases risk of nerve damage), smoking (nicotine damages spinal tissue, weakens bones and speeds wearing down of vertebral discs)
s&s: pain in buttocks, back of leg, foot and toes. This pain may be stabbing, burning or shooting, tingling in these regions (pins and needles), numbness, weakness, symptoms that get worse when moving, sneezing or coughing, usually is unilateral.
treatment: Most cases resolve in less than 4-6 weeks with no long-term complications. A person is more likely to experience chronic sciatica if patient has poor occupational mechanics, psychological depression and poor socioeconomic situations. short course of oral NSAIDs, opioid and non-opioid analgesics, muscle relaxants, anticonvulsants for neurogenic pain, oral corticosteroids if NSAIDs are inefficient, localised corticosteroid injections, spinal manipulation, deep tissue massage, physical therapy, surgical evaluation/ correction of structural abnormalities e.g., disc herniation or tumour, Acupuncture
ddx: herniated lumbosacral disc, muscle spasm, nerve root impingement, epidural abscess, tumour, Potts disease (spinal TB), piriformis syndrome
Upper motor neuron lesion
Neurons in brain and spinal cord
Caused by: illness, trauma, vitamin deficiency, stroke
Risks: virus exposure, genetics, immune system response
S&S: muscle weakness, increased muscle tone, increased muscle stretch reflex, involuntary contractions, muscle spasms, +ve babinski sign
Treatment: physical therapy, diet, muscle relaxers, Botox, tumour removal, medications
