Please enable JavaScript.
Coggle requires JavaScript to display documents.
Spinal Nerve Lesions - Coggle Diagram
Spinal Nerve Lesions
Median Nerve (C6-T1)
Wrist lesions
Due to lacerations or carpal tunnel syndrome
Results in weakness of abductor policis brevis and sensory loss over the radial 3.5 fingers and palm
Anterior interosseous nerve lesions:
Due to trauma
Weakness of flexion of the distal phalanx of the thumb and index finger
The median nerve is the nerve of precision grip
Proximal lesions e.g. compression at the elbow:
May show combined defects
Ulnar Nerve (C7-T1)
Most often, compression occurs at the epicondylar groove or at the point where the nerve passes between the 2 heads of flexor carpi ulnaris
Signs
Weakness and wasting of the innervated muscles of the hand
Vulnerable to elbow trauma
Treatment
Rest and avoiding pressure on the nerve
Night time soft elbow splinting may be required
Radial Nerve (C5-T1)
It may be damaged by compression against the humerus
Signs:
Test for wrist and finger drop with elbow flexed and arm pronated
Sensory loss is variable - the dorsal aspect of the root of the thumb is most reliably affected
This nerve opens the fist
Sciatic Nerve (L4-S3)
Lesions affect the hamstrings and all muscles BELOW the knee - resulting in foot drop
There is also loss of sensation below the knee laterally
Damaged by pelvic tumours or fractures to pelvis or femur
Tibial Nerve (L4-S3)
Lesions lead to an inability to stand on tiptoe (plantarflexion), invert the foot or flex the toes
Also sensory loss over the sole
Originates from the sciatic nerve just above the knee
Common Peroneal Nerve (L4-S1)
Often damaged as it winds round the fibular head due to trauma or sitting cross-legged
Signs - foot drop, weak ankle dorsiflexion/eversion, sensory loss over dorsal (top) of foot
Originates from the sciatic nerve just above the knee
Brachial Plexus
Pain/parathesiae and weakness in the affected arm in a variable distribution
Causes:
Trauma
Radiotherapy e.g. breast carcinoma
Prolonged wearing of a heavy rucksack
Neuralgic amyotrophy
Thoracic outlet compression
Phrenic Nerve
Consider phrenic nerve palsy if orthopnoea (shortness of breath when lying flat) with raised hemidiaphragm on CXR)
Causes: lung cancer, myeloma, thymoma, cervical spondylosis/trauam, phrenic nucleus lesion, thoracic surgery, C3-5 zoster, HIV, muscular dystrophy
Lateral Cutaneous Nerve of the Thigh (L2-L3)
Meralgia paraesthetica - antero-lateral burning thigh pain from entrapment under the inguinal ligament t