PNS Flashcards
Upper motor neuron lesion symptoms
Weakness
Disuse atrophy- from not using muscle
No fasculations (twitching)
Hyper reflexia
Hyper Tonia
Spasticity
Clonus
Babinski +ve
Lower motor neurone lesion symptoms
Weakness- limited to focal/root innervated pattern
Atrophy- prominent in focal pattern
Fasiculations
Hypo reflexia
Hypo Tonia
Babinski -ve
Flaccid paralysis
Lower motor neuron lesion
Affects nerve fibres travelling from lower motor neuron’s in anterior horn/anterior grey column of spinal cord, or in motor nuclei of cranial nerves and relevant muscles
Cause of lower motor neuron injury
Trauma to peripheral nerves that serve the axons, and viruses selectively attack ventral horn cells
Radial nerve impingement
Nerve travels from armpit down back of back to hand
Helps move arm, wrist and hand
Cause of radial nerve damage/impingement
- Broken arm bone and other injury
- Diabetes
- Improper use of crutches leading to excess pressure in the armpit
- Lead poisoning
- Long-term or repeated constriction of the wrist
- Long term pressure on the nerve, usually causes by swelling or injury of nearby body structures
- Pressure to the upper arm from arm positions during sleep or coma
S+S radial nerve impingement
- Abnormal sensations in the back and thumb side of the hand, or in the thumb, 2nd and 3rd fingers
- Weakness of fingers
- Loss of coordination of fingers
- Problem straightening the arm at the elbow
- Problem bending the hand back at the wrist or holding the hand
- Problems in the areas controlled by the nerve
o Px
o Numbness
o Decreased sensation
o Tingling
o Burning sensation
Radial nerve impingement prognosis
- In most cases the impingement can be treated successfully with a good chance of full recovery
- Sometimes no treatment is needed
- Medications can be used if needed
o Over the counter prescription px medications
o Corticosteroid injections around the nerve to reduce swelling and pressure - Supportive splint
- Elbow pad
- Physical therapy to maintain the muscle strength in the arm
Median nerve impingement
- Impingement of the median nerve
- Mononeuropathy that affects movement of or sensation in the hand
Median nerve impingement cause
- Caused by compression of the median nerve in the elbow or distally in the forearm or wrist with symptoms in the median nerve distribution only
- Injury
- Rheumatoid or wrist arthritis
- Stress from repetitive work
- Hobbies or sports activities
- Obesity
Median nerve impingement risks
- Sex
o Women more likely - Bone spurs
o Trauma or a condition that causes bone thickening, such as OA - Rheumatoid arthritis
- Thyroid disease
- Diabetes
- Overuse
- Obesity
- Pregnancy
- Prolonged bed rest
Median nerve impingement S+S
- Hand or wrist px, numbness, weakness or tingling
- Hand px that wakes you up at night
- Px, burning or tingling sensation in the forearm
- Problems grasping items, writing or using a keyboard
- Tenderness or px in the elbow
- Loss of muscle in the thumb (rare symptom)
Median nerve impingement prognosis
- Prognosis depends on the severity of the injury
- Prognosis for median nerve impingement is usually good
Ulnar nerve impingement
- Ulnar nerve entrapment affects your ulnar nerve in your arm
Ulnar nerve impingement cause
- Can occur when there is prolonged stretching of the nerve by keeping the elbow fully bent or when there is direct pressure on the nerve from leaning the elbow against a solid surface
- Entrapment at the wrist can occur when there is direct pressure on the berve by leaning on handlebars during long bike rides or prolonged use of hand tools
- Accidents
- Arthritis
- Broken bones or bone spurs
- Diabetes
- Dislocated elbow
- Tumours or cysts
Ulnar nerve impingement risks
- Sex
o Men more than women - Sports
o Baseball players
o Golfers
o Tennis players
o Bicyclists - Construction workers
- People who smoke
- Typists, writers and others who use a keyboard frequently
- Weightlifters
Ulnar nerve impingement S+S
- Px in forearm
- Tingling in forearm
- Numbness in forearm
- Weakness in the hand
- Tenderness in the hand
- Tingling in the palm and 4th and 5th fingers
- Sensitivity to cold
- Tenderness in the elbow joint
- Loss of muscle mass (in severe cases)
Ulnar nerve impingement prognosis
- Usually not serious
- But can have permeant consequences without prompt treatment
o Paralysis and loss of feeling in the affected hand or arm - With proper diagnosis and treatment most people with ulnar nerve impingement can make a full recovery
Musculocutaneous nerve impingement S+S
- Weakness in elbow or shoulder flexion
- Atrophy of biceps brachii
- P or paraesthesia at lateral forearm
Musculocutaneous causes
- Brachial plexus injury
- Compression injury- e.g., during weightlifting
- Shoulder dislocation
- Shoulder surgery
- Entrapment of nerve at elbow
Musculocutaneous prognosis
- Several months typically required after axonotmesis injury
- 2-9 months
Axillary S+S
- Shoulder or arm muscle weakness
- Shoulder or arm wasting
- Numbness in arm- around deltoid
Axillary cause
- Systemic disorder that causes nerve inflammation
- Fracture of humerus
- Pressure from cast or splint
- Shoulder dislocation
Axillary prognosis
- Full recovery usually occurs
- 6-12 months
Femoral nerve S+S
- Leg, ankle or foot numbness/tingling/weakness
- Lower back P
- Difficulty straightening knee, leg or ankle
- Muscle atrophy in legs
- Impaired gait
Femoral nerve impingement cause
- Direct trauma
- Prolonged pressure on nerve
- Compression, stretching or entrapment of nerve- e.g., by tumour or abnormal blood vessel
Femoral nerve impingement prognosis
- If left untreated, can lead to permanent damage or death of nerve
Obturator nerve impingement S+S
- Medial thigh or groin P
- Weakness with leg adduction
- Sensory loss in medial thigh of affected side
Obturator nerve cause
- Compression during pregnancy
- Can become entrapped at exit of obturator canal or more distally by fascia
- Trauma
- Nerve being stretch during surgery
Obturator nerve prognosis
- Without treatment, entrapment of obturator nerve can lead to ongoing P in groin
Sciatic nerve impingement S+S
- Painful- P may be stabbing, burning, stabbing
- Tingling- like pins and needles
- Numb down back of leg
- Weak hamstrings etc
Sciatic nerve causes
- Herniated disc
- Bony spur
Sciatic nerve prognosis
- Usually goes away on its own with time and self-care treatments
- Ice, stretching, NSAIDs
