Tmac\'s Nerve Tables - SSNT PDF

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Description

MEDIAN NERVE - (C5-T1)

Course

Formed by the junction of the lateral and medial cords in the axilla. Descends arm in the anterior compartment, adjacent to the brachial A. It travels through the cubital fossa as the most medial structure, then deep to the biceps aponeurosis (gives off branch to pronator teres here). It enters the forearm by passing between the 2 heads of pronator teres. In the proximal and middle forearm the N travels deep to FDS and superficial to FDP. It emerges superficially in the proximal forearm travelling medial to FCR. It is important to note that the palmar cutaneous branch of the N comes from the main body of the N before it enters the carpal tunnel. This branch supplies the skin of the palmer aspect of the hand (not the fingers). The branch supplying the thenar mm and the cutaneous branches to the fingers arise after the carpal tunnel.

Modes of Injury, Pt Inspection and History

 Neuropathy due to  Vascular (diabetes, microcirculation)  Inflammatory (RA, Synovitis)  Trauma  Metabolic (pregnancy, hypothyroidism)  Neoplastic (ganglions, lipoma, sarcoma)  Thoracic Outlet Syndrome  Carpal Tunnel Syndrome Dec pain, light touch, and vibration as well as the presence of paraesthesia in lateral 3.5 digits (all of ant aspect and distal area of dorsal aspect. Thenar wasting. No sensory disturbance in palmar aspect of hand.  Pronator Teres Syndrome Vague pain in proximal forearm (possibly) Dec pain, light touch, and vibration as well as the presence of paraesthesia in lateral 3.5 digits (all of ant aspect and distal area of dorsal aspect as well as palmar aspect of hand. Thenar wasting  Anterior Interosseous Syndrome FPL and radial side of FDP weakened – Pt find it difficult to produce a circle with the thumb and index finger whilst forcefully pinching these two digits together.

Supplies

Muscle Strength & Tone. Gait Assessment & Posture  Forearm flexors (apart from FCU  Decreased pronation if affected above elbow and the ulnar half of FDP)  Decreased wrist flexion if  Thenar muscles (apart from affected above elbow adductor pollicis & half of  Possible hypotonia of flexor pollicis brevis) arm pronation, wrist &  Lateral lumbricles finger flexor muscles

 No gait changes  Ape-hand deformity (loss of thumb opposition)

Reflexes & Specific Tests  Tinel’s Test (tap over flexor retinaculum)  Phalen’s Test (push back of hands together)  Median Nerve ULTT  Hand elevation test  Carpal tunnel compression test

ULNAR NERVE – (C8-T1)

Course

Continues from the medial cord of the brachial plexus in the axilla. Enters the arm anterior to teres major on the medial side of the brachial A in the anterior compartment. At about the mid-point of the arm it pierces the medial intermuscular septum and then continues in the medial aspect of the posterior compartment. It passes posterior to the medial epicondyle. The ulnar N enters the forearm by passing between the tendinous arch joining the humeral and ulnar heads of the FCU tendon (known as the cubital tunnel). The N traverses the forearm by passing wedged between the bellies of FDP and FCU. The N becomes superficial just proximal to the wrist and passes superficial to the flexor retinaculum, entering the hand by traversing the tunnel of guyon (between hook of hamate and pisiform, bridged by pisohamate ligament). The ulnar A also runs in the tunnel of Guyon, lateral to the N.

Modes of Injury, Pt Inspection and History

Supplies

 FCU  Neuropathy due to  Ulnar half of FDP  Vascular (diabetes, microcirculation)  Hypothenar muscles,  Inflammatory (RA, Synovitis) interossei, Adductor  Trauma pollicis, half of FPB and  Metabolic (pregnancy, hypothyroidism) medial lumbricles  Neoplastic (ganglions, lipoma, sarcoma)  Thoracic Outlet Syndrome  Elbow injuries – especially medial epicondyle #’s  Cubital Tunnel Syndrome Pain in the medial forearm. Positive compression test at elbow. Reproduction of SSx when elbow is flexed and wrist extended. Dec pain, light touch, and vibration as well as the presence of paraesthesia in the ulnar N distribution. May see atrophy of the hypothenar muscles. May have burning pain through nerve distribution. Wrist may deviate radially if pt attempts to flex wrist.  Tunnel of Guyon Syndrome May see atrophy of the hypothenar muscles Dec pain, light touch, and vibration as well as the presence of paraesthesia in the ulnar N distribution. May have burning pain through nerve distribution. No pain in forearm, elbow tests –ive. May have positive modified Tinnel’s sign over tunnel of Guyon

Muscle Strength & Tone. Gait Assessment & Posture  Decreased finger abduction  Dec ulnar deviation when flexing wrist concomitantly (cubital tunnel syndrome)

Reflexes & Specific Tests

 No reflex  Ulnar Nerve ULTT  Modified Tinel’s Test (tap over Tunnel of Guyon)  Flexion on elbow and extension of wrist for cubital tunnel syndrome.  When pt attempts to flex wrist it may  No gait changes deviate radially in  Ulnar claw (ring and cubital tunnel little fingers curl up if syndrome. sever late stage condition (in Tunnel of Guyon syndrome)

RADIAL NERVE C5-T1 Course

One of the terminal branches of the posterior cord (other is axillary N). It enters the arm medial to the humerus and anterior to the long head of triceps. It then descends inferolaterally passing around the humeral shaft (with the deep A of the arm) in the radial groove (in between the lateral and medial head of triceps). When the N reaches the lateral border of the humerus it pierces the lateral intermuscular septum and continues down the arm in the anterior compartment between brachialis and brachioradialis. Whilst traversing the cubital fossa (whilst in the radial tunnel) anterior to the lateral epicondyle, the N bifurcates into superficial (cutaneous) and deep (muscular and articular) branches. The superficial branch continues to travel deep to the brachioradialis mm, eventually emerging between it and the ECRL tendon. It runs superficial to the anatomical snuff box where it then divides into its many terminal branches to supply the cutaneous distribution of the radial N. The deep branch winds around the radial head, piercing supinator as it enters the posterior compartment of the forearm becoming the posterior interosseous N. It then travels down the forearm on the interosseous membrane. From when the N arises between the brachialis and brachioradialis muscles, during its course in the cubital fossa to when passes beyond the distal edge of supinator it is said to be in the radial tunnel. The N can either run deep to or pierce the supinator.

Modes of Injury, Pt Inspection and History

Supplies

 Neuropathy due to  All posterior brachial and  Vascular (diabetes, microcirculation) antebrachial muscles  Inflammatory (RA, Synovitis)  Trauma  Metabolic (pregnancy, hypothyroidism)  Neoplastic (ganglions, lipoma, sarcoma)  Thoracic Outlet Syndrome  Saturday Night Palsy Burning pain Motor and sensory deficits  Inappropriate use of crutches Burning pain Motor and sensory deficits  Radial Tunnel Compression Most commonly compressed by the fibrous proximal edge of the supinator mm (Frohse’s arcade). Pain in the proximal posterior forearm. Dec pain, light touch, and vibration as well as the presence of paraesthesia in the radial N distribution Weakness in wrist extension, especially with radial deviation.  Posterior Interosseous Syndrome Mainly due to compression within supinator of at distal aspect of supinator. Proximal forearm pain No sensory phenomena Marked weakness in wrist extensors Wrist drop.  Superficial Radial Nerve Syndrome Can be compressed anywhere along its path. Dec pain, light touch, and vibration as well as the presence of paraesthesia in the radial N distribution. No motor deficits. May be provoked by full pronation at wrist May be provoked by modified Tinnel’s sign near wrist.

Muscle Strength & Reflexes & Specific Tone. Gait Assessment Tests & Posture  Decreased elbow  Decreased extension, radial Brachioradialis reflex (C5/6) only deviation and wrist for compression supination (if affected proximal to elbow above the wrist)  Decreased Triceps  Decreased wrist & reflex (C7/8) finger extension  Radial nerve ULTT  Tinnel’s at wrist (superficial radial nerve compression only)  No gait changes  Wrist drop (inability to extend the wrist upward when the hand is pronated.

AXILLARY NERVE C5-C6 Course

Modes of Injury, Pt Inspection and History Terminal branch of the posterior  Focal Mononeuropathy  Thoracic Outlet Syndrome cord. Exits the axillary fossa posteriorly, passing through the  Shoulder Dislocations  Inappropriate use of crutches quadrangular space (bounded by the teres minor superiorly, May see atrophy of the deltoid the teres major inferiorly, the muscle long head of triceps medially Decreased function of Teres and the surgical neck of the Minor and Deltoid. humerus laterally – both axillary N and post circumflex humeral A run through it). It then winds around the surgical neck of the humerus, deep to deltoids (with the post humeral circumflex A).

Supplies  GH  Teres minor  Deltoids

Muscle Strength & Tone. Gait Assessment & Posture  Decreased shoulder abduction (impaired teres minor and deltoid function)  Possible hypotonia of deltoids

Reflexes & Specific Tests  No Reflex  No special test

 No gait changes  No postural changes

MUSCULOCUTANEOUS NERVE C5-C7 Course Terminal branch of the lateral cord. Exits axilla by piercing coracobrachialis and continues distally between biceps and brachialis. Emerges lateral to biceps as the lateral cutaneous N of the forearm just proximal to the cubital fossa.

Modes of Injury, Pt Inspection and History  Focal Mononeuropathy  Thoracic Outlet Syndrome  Shoulder Dislocations  Can become entrapped via biceps hypertrophy or compression by the aponeurosis.  Shoulder dislocation  Heavy backpacks Weakness of elbow flexion and supination of the forearm Dec pain, light touch, and vibration as well as the presence of paraesthesia in the lateral cutaneous N of the forearm distribution

Supplies  Biceps brachii  Coracobrachialis  Brachialis

Muscle Strength & Tone. Gait Assessment & Posture  Decreased elbow flexion and supination  Hypotonia of mm of ant compartment of arm

Reflexes & Specific Tests  Biceps reflex effected. ULTT

NOTES:  As the conditions are peripheral neuropathies, they are likely to occur unilaterally  ULTT – Upper Limb Tension Test -

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Hx of alcoholism Hx of diabetes Hx of hypothyroidism Medications – a number of meds can cause peripheral neuropathy Trauma to specific areas where peripheral nerves are vulnerable (included below) or damage to spinal nerves through vertebral DJD etc Onset: o Acute for trauma o Subacute for inflammatory o Chronic for toxic and metabolic courses Presence of burning pain, lancinating pain or uncomfortable paraesthesia (usual presentation for small fibre neuropathies) Experiencing numbness and tingling if so where? Single nerve distribution (mononeuropathy eg trauma) or distal with glove and stocking distribution (polyneuropathy eg diabetes or alcoholism)

LOWER LIMB NERVES NERVE Femoral (L2-4)

Lateral Cutaneou s (L2-3)

Obturator (L2-4)

Sciatic (L4-S3)

Tibial (L4-S3)

Common

Mechanism of Patient Inspection & Gait Assessment & Muscle Strength & injury/Pathologies History Posture Tone  Focal Mononeuropathy  Possible atrophy of  Quads weakness, so  Decreased hip flexion  Direct Trauma Quads difficulty with stairs (quads, + psoas)  Compression (ie.  Decreased function of  Knee ‘giving way’ when  Decreased knee tumour, henia) quads walking (quads) extension  Prolonged hip flexion (ie.  Occasionally pain in  Possible hypotonia of surgeries) quads hip and especially knee extension  Focal Mononeuropathy  Pain on lateral aspect  Antalgic posture if pain  No muscle strength  Meralgia Paraesthetica of the thigh on outer thigh or in changes  Compression (ie.  Hypersensitivity to groin/buttocks  No muscle tone tumour) heat changes  Tight belt can compress  Possible aching in the nerve groin and buttocks  Focal Mononeuropathy  Deep ache in adductor  Antalgic posture if pain  Decreased adduction in groin/along  Sporting injuries (“pulled origin region strength adductor pathway  Decreased function of groin”)  Possible hypotonia of the adductor muscles  Compression (ie. hip adduction  Exercise-evoked pain tumour) along adductors and associated weakness  Deep sharp pain in  Focal Mononeuropathy  L4/5 – Difficulty heel  Possible decreased buttocks down back  Disc pathologies walking. Foot drop knee flexion strength of leg  Compression (ie  S1 – Difficulty toe  Possible hypotonia of  Decrease function of walking tumour, piriformis) hamstrings knee flexors and  Injury from injections  Swing phase from the muscles of the lower hips if difficulty flexing limb knee  Numbness and tingling depending on where nerve is compressed  Possible decreased  Decreased function of Difficulty toe walking Focal mononeuropathy plantar flexion, foot plantar and foot Reciprocal from sciatic flexion, intra foot flexors Vulnerable at popliteal movements  Possible atrophy of fossa  Hypotonia through foot musculature, post Fracture of tib/fib posterior tib compartment compartment  Focal mononeuropathy  Possible decreased  Foot drop gait  Decreased

Reflexes & Specific Tests  Decreased quadriceps reflex (L2-4)  No special tests (that we have been taught)

Sensory Findings

 No Reflex  No special tests

 Decreased pain, light touch, vibratory and propriceptive sensation on the lateral aspect of thigh  Decreased pain, light touch, vibratory and propriceptive sensation on the medial thigh (small spot, just below mid thigh)

 No Reflex  No specific tests

 Straight leg raise  Slump test  Decreased Achilles reflex

Decreased Achilles reflex

 (Tinnels sign over

 Decreased pain, light touch, vibratory and propriceptive sensation on the medial leg & calf (saphenous nerve)

 Decreased pain, light touch, vibratory and propriceptive sensation dispersed through lower limb depending on where the nerve is affected.

 Decreased pain, light touch, vibratory and propriceptive sensation dispersed through the sole of the foot (mainly calcaneal region)  Decreased pain, light

Peroneal (L4-S2)

   

Superior Gluteal (L4-S1)

 Focal mononeuropathy  Compression of spinal nerves

Inferior Gluteal (L5-S2)

Long periods of bed rest function in foot Prolonged crossed legs dorsiflexion and Fracture fibula eversion Peroneal strike Possible atrophy anterior/lateral compartment muscles

Possible decreased function in abduction, medial rot of hip Possible atrophy glut complex  Focal mono neuropathy Possible decreased  Compression of spinal function in extension nerves of hip Possible atrophy glut complex

Slapping gait

Trendelenberg

 gait

 Hip swing gait

dorsiflexion / eversion of foot  Hypotonia of ant/lateral compartments of leg

fibula neck)  No Reflex

 Decreased abduction medial rotation of the hip  Hypotonia of gluts

 No Reflex

 Decreased extension of the hip  Hypotonia of gluts

 No Reflex

touch, vibratory and proprioceptive sensation dispersed through the lateral and anterior compartments of the leg and foot (excluding calcaneal region)  None

 None

NERVE PATHWAYS OF LOWER LIMB ANTERIOR Femoral nerve: Formed by branches from the anterior rami of the L2-4 nerve roots. Emerges lateral to the psoas major muscle as one of the terminal branches of the lumbar plexus. Runs inferolaterally in the posterior abdomen and then into the pelvis on iliacus. Passes posterior to the inguinal ligament to enter the femoral triangle as the most lateral structure (passes posterior to the inguinal ligament approximately half way along it). It then divides up into many muscular branches and cutaneous branches in the femoral triangle. There is one terminal branch that continues to run with the femoral artery and vein; the saphenous nerve. This saphenous nerve passes through the adductor canal however not through the adductor hiatus. It pierces the medial fascia lata in the distal thigh to become cutaneous. Is passes medial to the knee, giving off infrapatellar branches here. It then continues as a cutaneous nerve into the anteromedial aspect of the lower leg, supplying the skin in this area. Obturator nerve: Formed by branches from the anterior rami of the L2-4 nerve roots. Emerges medial to the psoas major muscle and then enters the lesser pelvis. Exits the pelvis with the obturator vessels via the obturator canal to enter the medial thigh. Here is gives motor supply to the adductor muscles and cutaneous supply to the superior aspect of the medial thigh. Lateral cutaneous nerve of the thigh: Formed by branches from the anterior rami of the L2/3 nerve roots. Emerges lateral to the psoas major muscle as one of the terminal branches of the lumbar plexus. Passes inferolaterally on iliacus until it enters the thigh by passing just medial to the ASIS (posterior to the inguinal ligament). Becomes cutaneous immediately and supplies the skin on the lateral aspect of the thigh. Has no motor aspects. POSTERIOR: Posterior femoral cutaneous nerve: Leave the pelvis via the greater sciatic foramen inferior/medial to the sciatic nerve. It then descends inferolaterally in the gluteal region, quickly becoming cutaneous at the junction of the gluteal region and posterior thigh as it is superficial to the ischial tuberosity. It descends the posterior thigh superficial to the biceps femoris. Sciatic nerve: Formed by branches from the anterior rami of the L4-S2 nerve roots as part of the sacral plexus. The forming of the nerve happens in the pelvis, on the anterior surface of the piriformis muscle. The nerve has two parts, a common peroneal part and a tibial part. The nerve exits the pelvis via the greater sciatic foramen to enter the gluteal region. It emerges from the inferior aspect of piriformis and then descends inferolaterally in the gluteal region posterior to the GOGO muscles and quadratus femoris and anterior (deep) to gluteus maximus. The nerve the enters the posterior thigh lateral to the ischial tuberosity and descends the thigh under the cover of the biceps femoris muscle. At the superior apex of the popliteal fossa the nerve divides into its branches- the tibial nerve and the common peroneal nerve. Tibial nerve: Is part of the sciatic nerve until its termination at the apex of the popliteal fossa. The tibial nerve then transects the popliteal fossa from superior to inferior apex. It enters the posterior compartment via the popliteal canal (gap between the soleus origin) and descends the leg with the posterior tibial vessels, in between the superficial and deep posterior compartments, posterior to tibialis posterior. It crosses the ankle medially in the tarsal tunnel and then divides into the medial and lateral plantar nerves to supple the muscles and skin of the plantar aspect of the foot.

Common peroneal nerve: Is part of the sciatic nerve until its termination at the apex of the popliteal fossa. The common peroneal nerve follows the medial aspect of the biceps femoris muscle in the popliteal fossa. It exits the fossa on the lateral side as it winds around the neck of the fibula. Here it enters the lateral compartment of the leg and then divides into its two terminal branches, the superficial and deep peroneal nerves. Superficial peroneal nerve: Stays in the lateral compartmen...