(3) BRACHIAL NEURALGIA (Neuralgic amyotrophy) -may follow injuryPain is usually the first symptom,

detail Treatment - Minor symptoms can be relieved by appropriate physiotherapy, but progressive neurological deficit calls for
surgical interference. (2) MALIGNANT INFILTRATlON -of brachial plaxus may resut from either upward extension of apical lung carcinoma, or local metastalic spread from mammary carcinoma. Pain and sensory loss in medial aspect of forearm and slowly progressive weakness which starts in the small hand muscles. (3) BRACHIAL NEURALGIA (Neuralgic amyotrophy) -may follow injury, operation, inoculation or specific fever. Pain is usually the first symptom, often severe and of sudden onset, followed after several days or few weeks by weakness and wasting of muscles, especially those innervated by C5 and C6 cord segments. Sensory loss is mild or absent and there are usually few or no constitutional symptoms. Recovery is slow 4. Fibrositis. periarthritis and arthritis of the shoulder - Diseases of shoulder joint and its surrounding structures should be considered. Pain referred to the shoulder, to arm, or to region of elbow, associated with loss of range of movement or pain on movement. Treatment - None specific. In acute stage arm should tie supported in a sling. Physiotherapy as soon as pain subsides. 5. Lesions of median nerve - Carpal tunnel syndrome (See p. 477). 6. Vascular conditions - Those producing sensory disturbances in arm include occlusion of brachial artery due to embolus, or ischemia from polyarteritis nodes a, scleroderma and other conditions grouped under' the term Raynaud's phenomenon. Inspection of the skin, changes in temperature and colour of the limb, and inadequate pulse at the wrist facilitate diagnosis. Coronary insufficiency may be responsible for pain in the ulnar aspect of arm and forearm. THE LUMBOSACRAL PLEXUS Sciatica Defination -Pain in ihe distribution of the sciatic nerve or its component nerve roots. The syndrome is now accepted as being caused by lumbar disc prolapse. However, sciatic nerve lesions can occur due to pressure in the buttock or upper part of thigh. Causes -1 TRUE SClATIC NEURITIS - Leprosy, polyarteritis nodosa, nerve injury due to infections or trauma, post-herpetic neuralgia. II. MECHANICAL PRESSURE ON NERVES OR ROOTS OR REFERRED PAIN-1. In the spinal cord - Tumours of cauda aquina, arachnoiditis, rarery thrombosis, haemorrhage or infection irritating meninges of the cord. 2. In the cord space - Protruded intervertebral disc. extramedullary tumours. 3. In the vertebral column - Arthritis. Tuberculosis, spondylolisthesis. ankylosing spondylitis. primary bone tumours. secondary carcinoma 4. In the back - Fibrositis of posterior sacral ligaments. Compression where the nerve leaves the pelvis in those who he immobile on a hard surface for long time (a form of Saturday nignt palsy). 5. In the thigh and buttock - Fibrositis, sacro-sciatic band, hip joint or sacroiliac joint disease, neurofibroma, haemorrhage within or adjacent to nerve sheath in blood dyscrasias and anticoagutant therapy, misplaced therapautic infection 6. In the pelvis - Sacroiliac arthritis or strain, hip disease, infection of prostate or female genital tract, rectal impactions, tumors of lumbo-sacral plaxus. INVESTIGATION OF A CASE OF SCIATICA I. History - Of irauma, exposure to damp or cold, sphincter control and history of previous attacks. Typs of radiation whether nerve root type or vaguely localised deep aching pain. Paraesthesia will occur in pain from sensory pathways but not in referred pain. Pain down the leg on coughing in root lesions and also acute extraneural disease of spine, pelvis and sacroiliac joints. II. Physical examination - 1. LUMBAR SPINE - Shape, mobility, muscle -spasm, list to one or other side on standing (sclatic scoliosis), local tenderness and presence of trigger points in back and limbs. Sciatica may be the first symptom of spinal caries. 2. SPECIAL SIGNS - (i) SLR test -Restriction of straight leg raising is usually much more marked in lesions affecting the nerve roots than in purely skeletal affections. SLR test gives a useful indication of the severity of the sciatica, and increased capacity for painless SLR is objective measure of improvement. (ii) Tenderness of nerves (iii) Intensification of pain in back and lag during rotatory extension of lumbar spine very suggestive of ruptured disc. (iv) Popliteal compression - Radiating pain can often be aggravated by pressure over the course of the tibial narve through the popliteal fossa. It is an additional finding in favour of root compression. (v) Testing of the sacroiliac joints by pressure on the two anterior superior iliac spines. (vi) Estimation of range and painlessnees or otherwise of hip joint by passive stretching. (vii) Muscle power in the lower limb tested against resistance. (viii) Knee and ankle jerks - When L4 root is involved knee jerk is depressed and there is likely weakness of tibialis anterior muscle. L5 root lesions, both knee and ankle ierks usually brisk but there may be weakness of dorsiflexion of the toes particularly of extensor hallucis longus. S1 root ankle jerk lost and weakness, when present involves the calf muscles (ix) Tone and size of gluteal muscles judged by asking patient to contract both buttocks, in upper sacral root lesions marked wasting may be clearly visible. 3. SENSATIONS -impairment of perception of pin-prick commonly found on dorsurn of foot if implication of 5th lumbar and 1st sacral nerve roots .4.