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What is the general feature of GBS?
- Weakness beginning in the distal limbs but rapidly advancing to affect proximal muscle function (“ascending paralysis”)
- immune-mediated demyelinating neuropathy
- inflammation and demyelination of spinal nerve roots and peripheral nerves (radiculoneuropathy)
- Infections with Campylobacter jejuni, cytomegalovirus, Epstein-Barr virus, and Mycoplasma pneumoniae
- Ab to gangliosides
- T cell–mediated immune response ensues, accompanied by segmental demyelination induced by activated macrophages
What are the morphoological features of GBS?
- Inflammation of peripheral nerve, manifested as perivenular and endoneurial infiltration by lymphocytes, macrophages
- Most intense in spinal and cranial motor roots
- Segmental demyelination affecting peripheral nerves is the primary lesion, but damage to axons is also characteristic, particularly when the disease is severe
- The cytoplasmic processes of macrophages penetrate the basement membrane of Schwann cells, particularly in the vicinity of the nodes of Ranvier, and extend between the myelin lamellae, stripping away the myelin sheath from the axon
What are the diagnostic findings in GBS?
- Ascending paralysis (symmetric)
- Absent DTR
- Reduced NCV
- Sensory involvement (mainly subjective)
- There is elevation of the CSF protein due to inflammation and altered permeability of the microcirculation within the spinal roots as they traverse the subarachnoid space.
- NO CSF PLEOCYTOSIS
What are the nerve lesions in LL?
- In lepromatous leprosy, Schwann cells are invaded by Mycobacterium leprae, which proliferate and eventually infect other cells.
- There is evidence of segmental demyelination and remyelination and loss of both myelinated and unmyelinated axons.
- As the infection advances, endoneurial fibrosis and multilayered thickening of the perineurial sheaths occur.
- Symmetric polyneuropathy affecting the cool extremities (due to lower temperatures favoring mycobacterial growth).
- Prominently involves pain fibers, and the resulting loss of sensation contributes to injury (large traumatic ulcers may develop in the extremities)
What is the feature of nerve involvement in TT?
- Active cell-mediated immune response to M. leprae, with nodules of granulomatous inflammation situated in the dermis.
- The inflammation injures cutaneous nerves in the vicinity; axons, Schwann cells, and myelin are lost, and there is fibrosis of the perineurium and endoneurium.
- In tuberculoid leprosy, affected individuals have much more localized nerve involvement
What is the main pathogenesis in TT and LL?
- TT--> granuloma
- LL--> schwann destruction by M.Leprae
What are the nerve lesions of diphteria?
- Begins with paresthesias and weakness
- Early loss of proprioception and vibratory sensation.
- The earliest changes are seen in the sensory ganglia, where the incomplete blood-nerve barrier allows entry of the toxin.
- There is selective demyelination of axons that extends into adjacent anterior and posterior roots as well as into mixed sensorimotor nerves
VZV occurs most frequently in ...............
thoracic or trigeminal
What is the morphology of Zoster infection?
- Affected ganglia show neuronal destruction and loss, usually accompanied by abundant mononuclear inflammatory infiltrates; regional necrosis with hemorrhage may also be found.
- Peripheral nerve shows axonal degeneration after the death of the sensory neurons.
- Intranuclear inclusions generally are not found in the peripheral nervous system.
True or False: IN inclusions are seen in zoster of PNS
What are the types of hereditary neuropathies?
- Hereditary motor and sensory neuropathies (HMSNs)
- Hereditary sensory and autonomic neuropathies (HSANs)
- Familial amyloid polyneuropathies--> like HSAN+transtyrethin
- Peripheral neuropathy accompanying inherited metabolic disorders
What are the findings of PNS in XLALD?
- ATP-binding cassette (ABC), transporter protein
- Mixed motor and sensory neuropathy, adrenal insufficiency, spastic paraplegia; onset between 10 and 20 years for males with leukodystrophy, between 20 and 40 years for females with myeloneuropathy
- Segmental demyelination, with onion bulbs; axonal degeneration (myelinated and unmyelinated); electron microscopy—linear inclusions in Schwann cells
What are the findings of PNS in Familial amyloid polyneuropathies?
- Sensory and autonomic dysfunction; age at onset varies with site of mutation
- Amyloid deposits in vessel walls and endoneurium with axonal degeneration
What are the findings of PNS in AIP?
- porphobilinogen deaminase deficiency (11q)
- Acute episodes of neurologic dysfunction, psychiatric disturbances, abdominal pain, seizures, proximal weakness, autonomic dysfunction; attacks may be precipitated by drugs
- Acute and chronic axonal degeneration; regenerating clusters
What are the findings of PNS in Refsum disease?
- Peroxisomal enzyme phytanoyl CoA α-hydroxylase
- Mixed motor and sensory neuropathy; palpable nerves; ataxia, night blindness, retinitis pigmentosa, ichthyosis;
- age at onset before 20 years
- Severe onion bulb formation
What is the mc hereditary neuropathy?
HMSN I, results in demyelination of peripheral nerve and slowing of the velocity of axonal conduction
What is the hallmark of CMT?
- progressive muscular atrophy of the leg below the knee
- Pes Cavus
Genetic defect in CMT is.....................
peripheral myelin protein 22 (PMP22) on chromosome 17p (duplicated)
What is the morphology of CMT?
- Demyelinating neuropathy.
- Repetitive demyelination and remyelination, with multiple onion bulbs, more pronounced in distal nerves.
- The axon is often present in the center of the onion bulb, and the myelin sheath is usually thin or absent.
- The redundant layers of Schwann cell hyperplasia surrounding individual axons are associated with enlargement of involved peripheral nerves that may become palpable.
CMT is inherited as .......disorder
What are the features of HMSN II?
- Similar to HMSNI
- Without Nerve enlargement
- Loss of myelinated axons
- Segmental demyelination of internodes is infrequent.
- The site of primary cellular dysfunction is the axon or neuron
What are the features of Dejerine-Sottas Neuropathy (HMSN III)?
- Slowly progressive, AR begins in early childhood, and is manifested by delay in developmental milestones
- Involves limb and trunks
- enlarged peripheral nerves
- DTR diminished
- Marked increase in size of individual peripheral nerve fascicles with abundant onion bulb formation and segmental demyelination more distal
- Axonal loss
Which types of diabetic neuropathy are found together?
sensorimotor and autonomic
What are the possible involved mechanisms in diabetic neuropathy?
polyol pathway and the nonenzymatic glycation of proteins
What is the hallmark pathological finding in diabetic polyneuropathy?
- Axonal neuropathy
- segmental demyelination
- Relative loss of small myelinated fibers and of unmyelinated fibers
- Endoneurial arterioles show thickening, hyalinization, and intense periodic acid–Schiff positivity in their walls and extensive reduplication of the basement membrane
- Diabetic neuropathy with marked loss of myelinated fibers, a thinly myelinated fiber (arrowheads), and thickening of endoneurial vessel wall (arrow).
Diabetic neuropathy is.......
The most common peripheral neuropathy in type 2 diabetes mellitus is ...................
Distal symmetric sensorimotor neuropathy (sen>mot)
Diabetic ANS neuropathy always occur in conjunction with......
Distal symmetric sensorimotor neuropathy
Mononeuropathy in diabetes is a result of........
What are the features of uremic neuropathy?
- 1) Distal, symmetric neuropathy2) Muscle cramps, distal dysesthesias, and diminished DTR.
- 3)Axonal degeneration is the primary event; 4)Regeneration and recovery are common after dialysis
Diabetic and uremic neuropathy are....................
B1 and B12 deficiency are associated with ............neuropathy
Which vitamin deficiencies cause axonal neuropathy?
Ethanol directly cause.............neuropathy
What are the direct neuropathies causes by tumors?
- Brachial plexopathy from neoplasms of the apex of the lung
- Obturator palsy from pelvic malignant neoplasms
- Cranial nerve palsies from intracranial tumors and tumors of the base of the skull.
- A polyradiculopathy involving the lower extremity may develop when the cauda equina is involved by meningeal carcinomatosis
What are the features of malignancy associated paraneoplastic neuropathy?
- most common type is a sensorimotor neuropathy in lower limbs
- small-cell carcinoma of the lung
- inflammatory infiltrates within the dorsal root ganglia and the identification of IgG antibodies that bind a 35- to 38-kD RNA-binding protein expressed by neurons and the tumor
What is the neuropathy caused by MM?
- Deposition of light-chain (AL type) amyloid in peripheral nerves
- Production of monoclonal immunoglobulin that recognizes a major protein of myelin, myelin-associated glycoprotein
What is traumatic neuroma (pseudoneuroma or amputation neuroma)?
- Axons, even in the absence of correctly positioned distal segments, may continue to grow, resulting in a mass of tangled axonal processes known as a traumatic neuroma (pseudoneuroma or amputation neuroma). Within this mass, small bundles of axons appear randomly oriented; each, however, is surrounded by organized layers containing Schwann cells, fibroblasts, and perineurial cells
- Normal appearance of peripheral nerve (A), with all the axons aligned in a single plane with sheaths of connective tissue, as compared with traumatic neuroma (B) showing disordered orientation of axons (pale purple) intermixed with connective tissue
What are the features in CTS?
- compression of the median nerve at the level of the wrist within the compartment delimited by the transverse carpal ligament
- Frequently bilateral
- edema, pregnancy, inflammatory arthritis, hypothyroidism, amyloidosis (especially that related to β2-microglobulin deposition in individuals on renal dialysis), acromegaly, diabetes mellitus, and excessive repetitive motions of the wrist.
- Symptoms are limited to dysfunction of the median nerve, including numbness and paresthesias of the tips of the thumb and first two digits.
What are other compression neuropathies?
- Other nerves prone to compression neuropathies include the ulnar nerve at the level of the elbow, the peroneal nerve at the level of the knee, and the radial nerve in the upper arm; the latter occurs from sleeping with the arm in an awkward position (“Saturday night palsy”).
- Another form of compression neuropathy is found in the foot, affecting the interdigital nerve at intermetatarsal sites. This problem, which occurs more often in women than in men, leads to foot pain (metatarsalgia). The histologic findings of the lesion (Morton neuroma) include evidence of chronic compression injury
What are the symptoms of C5 injury?
- Pain : Neck, shoulder, scapula
- Sense: Lateral arm (in distribution of axillary nerve)
- Motor: Shoulder abduction, external rotation, elbow flexion, forearm supination
- DTR: Biceps, brachioradialis
What are the symptoms of C6 injury?
- Pain: Neck, shoulder, scapula, lateral arm, lateral forearm, lateral hand
- Sense: Lateral forearm, thumb and index finger
- Motor: Shoulder abduction, external rotation, elbow flexion, forearm supination and pronation
- DTR: Biceps, brachioradialis
What are the symptoms of C7 injury?
- Pain: Neck, shoulder, middle finger, hand
- Sense: Index and middle finger, palm
- Motor: Elbow and wrist extension (radial), forearm pronation, wrist flexion
- DTR: Triceps
What are the symptoms of C8 injury?
- Pain: Neck, shoulder, medial forearm, fourth and fifth digits, medial hand
- Sense: Medial forearm, medial hand, fourth and fifth digits
- Motor: Finger extension, wrist extension (ulnar), distal finger flexion, extension, abduction and adduction, distal thumb flexion
- DTR: None
What are the symptoms of T1 injury?
- Pain: Neck, medial arm and forearm
- Sense:Anterior arm and medial forearm
- Motor: Thumb abduction, distal thumb flexion, finger abduction and adduction
- DTR: None
What are the symptoms of L5 injury?
- Symptoms: Back pain radiating down the lateral leg to foot
- Signs: Decreased foot dorsiflexion, toe extension, foot inversion and eversion; mild weakness of leg abduction in severe cases
What are the symptoms of S1 injury?
- Symptoms: Pain radiating down the posterior leg to foot; leg pain greater than back pain
- Signs: Decreased leg extension, foot inversion, plantar flexion, and toe flexion; decreased sensation in the posterior leg and lateral foot; loss of ankle jerk
What are the symptoms of L2-4 injury?
- Symptoms: Acute back pain radiating around the anterior leg into the knee and possibly foot
- Signs: Decreased hip flexion, knee extension, leg abduction; decreased sensation in the anterior thigh down the medial aspect of the shin; diminished knee jerk in severe cases
What are the symptoms of S2-4 injury?
- Symptoms: Sacral or buttock pain radiating down the posterior leg or into the perineum
- Signs: Minimal weakness; bowel and bladder dysfunction
What are the features of mercury poisoning?
paresthesias in hands and feet that progress proximally and may involve the face and tongue. Motor weakness can also develop. CNS symptoms often overshadow the neuropathy
What is the hallmark of Lead peripheral neuropathy?
- insidious and progressive onset of weakness usually beginning in the arms, in particular involving the wrist and finger extensors, resembling a radial neuropathy.
- Sensation is generally preserved; however, the autonomic nervous system can be affected
Lead peripheral neuropathy is primarily......
What is the effect of arsenic on peripheral nerves?
- The presenting symptoms are typically an abrupt onset of abdominal discomfort, nausea, vomiting, pain, and diarrhea followed within several days by burning pain in the feet and hands.
- Examination of the skin can be helpful in the diagnosis as the loss of the superficial epidermal layer results in patchy regions of increased or decreased pigmentation on the skin
What are the features of Common peroneal injury?
- Site: Fibular neck, just below the knee
- Cause: Prolonged lying, leg crossing, squatting, leg cast
- Symptoms: Foot drop, paresthesias and/or sensory loss over dorsum of foot and lateral shin
- Signs: Weakness on foot dorsiflexion and eversion; sensory loss on dorsum of foot; reflexes normal
What are the features of deep peroneal injury?
- Site: Ankle
- Cause: Tight fitting shoe rim or strap
- Symptoms: Ankle pain, minimal weakness and sensory loss over web space between digits 1 and 2
- Signs: Minimal
What are the features of Posterior tibial injury?
- Site: Tarsal tunnel of ankle
- Cause: Fracture or dislocation of talus, calcaneus, medial malleolus, rheumatoid arthritis, tumor
- Symptoms: Aching, burning, numbness, tingling on sole of foot, distal foot, toes, and occasionally heel
- Signs: Positive Tinel's sign over nerve posterior to medial malleolus; sensory loss on sole of foot; atrophy of foot muscles if severe
What are the features of Sciatic injury?
- Site: Sciatic notch/gluteal region, midthigh
- Cause: Trauma (hip dislocation, fracture, or replacement), prolonged bed rest, deep-seated pelvic mass, piriformis syndrome
- Symptoms: Leg pain and weakness affecting most lower leg muscles
- Signs: Sensory loss in peroneal, tibial, and sural territories; may spare medial calf and arch of foot; normal knee jerk; absent ankle jerk
What are the features of femoral injury?
- Site: Pelvis and anterior thigh
- Cause: Hip or pelvic fracture, hip replacement, lithotomy position, diabetes mellitus
- Symptoms: Quadriceps weakness and sensory loss
- Signs: Quadriceps weakness; sensory loss over anterior and medial thigh extending down medial shin to arch of foot; reduced or unobtainable knee jerk
What are the features of Lateral femoral cutaneous injury?
- Site: Inguinal ligament (meralgia paresthetica)
- Cause: Obesity, tight fitting belts, idiopathic
- Symptoms: Paresthesias and pain radiating down the lateral thigh to knee
- Signs: Sensory loss on lateral thigh
What is the summary of lesions seen in upper limb nerve injury?
- 1) Erb’s palsy------upper trunk
- 2) Klumpke’s palsy---- lower trunk
- 3) Winging of scapula----long thoracic nerve
- 4) Ape’ s hand---- median nerve---supracondylar fracture
- 5) Wrist drop------ Radial nerve---fracture of spiral groove
- 6) Claw hand-----ulnar nerve----- fracture of medial epicondyle
What are the branches of brachial plexus?
- BRANCHES FROM ROOTS & TRUNKS
- ROOTS: Dorsal scapular nerve C5, Long thoracic nerve C5,6,7
- UPPER TRUNK: C5 C6 Suprascapular nerve , Nerve to subclavius
- BRANCHES FROM LATERAL CORD: Lateral pectoral nerve, Musculocutaneous nerve, Lateral root of median
- BRANCHES FROM MEDIAL CORD: Medial pectoral nerve, Medial cutaneous nerve of arm and forearm, Ulnar nerve, Medial root of median
- BRANCHES FROM POSTERIOR CORD: Upper and lower subscapular nerves, Thoracodorsal, Axillary nerve, Radial nerve
What are the findings in upper lesions of brachial plexus?
- Traction or even tearing of C5 and C6 root
- Cause: Excessive displacement of head to opposite side and depression of shoulder on same side, In infants during a difficult delivery, In adults following a fall on or a blow to the shoulder
- Nerves involved: Supra scapular nerve, Nerve to Subclavius, Musculocutaneous nerve ,Axillary
- MUSCLES AND FUNCTIONS LOST: Lateral rotation of arm: Teres minor, Infraspinatus Abduction of shoulder: Supraspinatus, Deltoid Flexion of shoulder: corobrachialis, Biceps brachii Flexion of elbow: Brachialis, Biceps brachii Supination of forearm: Biceps brachii
- ERB’S PALSY (UPPER TRUNK INJURY)• Loss of muscle function innervated by C5 and C6• Also known as waiter’s tip or policeman’s tip• Arm medially rotated, adducted, hangs by side• Forearm extended and pronated
Which nerves are involved in Erb Paralysis?
Suprascapular, Subclavius, Musculocutaneous, Axillary
What is the manifestation of upper trunk injury?
Arm medially rotated, adducted, hangs by side• Forearm extended and pronated
What are the features of Klumpke paralysis?
- Fibers of C8 and mostly T1 root are torn
- Cause:Excessive abduction of arm a) Birth injury in breech delivery b) Person falling from a height clutching an object to save himself Compression of lower trunk a) Cervical rib b) Malignant mets in lower deep cervical lymph nodes
- Nerves involved T1 fibers run in ulnar and median nerve
- Muscles involved: All small muscles of the hand( interossei and lumbricals)
- Sensory loss along the medial side of forearm
- KLUMPKE,S PALSY: Clawed hand• Hyperextension of metacarpophalangeal joint----- by unopposed extensor digitorum • Flexion at interphalangeal joint by unopposed flexor digitorum superficialis and profundus
What are the symptoms of Klumpke paralysis?
- Clawed hand
- Hyperextension of metacarpophalangeal joint----- by unopposed extensor digitorum
- Flexion at interphalangeal joint by unopposed flexor digitorum superficialis and profundus
What are the symptoms of Long thoracic injury?
- Arise from roots c5 , c6 and c7
- Muscles involved Serratus anterior
- Functions lost Abduction above 90 degrees
- Causes:• Blows or pressure in posterior triangle of neck• In radical mastectomy
- Deformity: Winging of scapula vertebral border and inferior angle of scapula unduly prominent
What are the features of axillary injury?
- Arise from posterior cord of brachial plexus
- Causes: a. Fracture of surgical neck of humerus, b. Inferior dislocation of shoulder joint, c. Pressure of badly adjusted crutch upward into armpit, d. Misplaced injection into deltoid
- Muscles involved• Deltoid • Teres minor
- Sensory loss • Upper lateral cutaneous nerve of arm• Loss of skin sensation over the lower half of deltoid muscle
What is the characteristic of radial nerve?
- Largest branch of plexus•
- From posterior cord
- Arise in axilla ---> spiral groove -> lateral intermuscular septum -> front of lateral epicondyle -> divides into superficial and deep• Superficial --> lateral side of radial artery --> posterior surface of wrist/ Deep branch -->supinator --> neck of radius --> posterior surface of wrist
What are the branches of radial nerve?
- Axilla• Posterior cutaneous nerve of ARM• Nerve to long head and medial head of triceps
- Branches in spiral groove• Lower lateral cutaneous nerve of arm• Posterior cutaneous nerve of forearm• Nerve to lateral and medial head of triceps
- Branches in anterior compartment of arm:• Nerve to small part of brachialis• Nerve to brachioradialis• Nerve to ECRL
- Branches in cubital fossa:• Deep branch of radial nerve to ECRB, supinator and all muscles in posterior compartment of forearm• Superficial branch provides sensation to dorsum of hand and dorsum of
- Branches in distal fore arm• Palmar cutaneous branch----skin on lateral side of palm
- Branches in palm• Muscle of thenar eminence• First 2 lumbricals • Skin of palmar surface of lateral 3 ½ fingers• lateral 3 ½ fingers
What are the features of radial nerve injury in axilla?
- Causes• Pressure of badly fitted crutch into armpit• Falling asleep with arm over the back of chair------ Saturday night palsy
- Motor loss:• Extension at elbow----- paralysis of triceps and anconeus• Extension of wrist and fingers-----paralysis of extensors of wrist and all muscles of posterior compartment• Supination----can still be performed by biceps
- Deformity known as WRIST DROP -----flexion of wrist as a result of action of unopposed flexors of wrist and fingers
- Sensory loss• posterior surface of arm and fore arm• Dorsum of hand and dorsal surface of lateral 3 ½ fingers
What are the features of radial injury in spiral groove?
- Most commonly in distal part of groove beyond the origin of nerves to triceps and anconeus and cutaneous nerves
- Causes:• Fracture of shaft of humerus• Prolonged pressure on the back of arm as in• Unconscious patient by edge of operating table• Prolonged application of tourniquet in thin lean person
- Motor loss:• Extension of wrist, fingers and thumb• Elbow extension is spared
- Sensory loss: • Dorsum of hand and dorsum of lateral 3 ½ fingers• Sensations on posterior arm and forearm are spared
What is the major difference in radial nerve injury between spiral groove and axilla?
In spiral groove: Elbow extension and Sensations on posterior arm and forearm are spared
What are the features of median nerve?
- 1) Formed in axilla by lateral and medial roots from respective cords
- 2) Anterior compartment of arm ---- crosses brachial artery from lateral to medial
- 3) At elbow crossed by bicipital aponeurosis
- 4) Passes between 2 heads of pronator teres to enter forearm
- 5) At wrist at lateral border of flexor digitorum profundus6) Enter palm beneath flexor retinaculum
What are the branches of median nerve?
- 1) Branches in axilla and arm• no branches
- 2) Branches in proximal forearm• To all anterior compartment muscles except flexor carpi ulnaris and medial half of flexor digitorum profundus
- 3) Branches in distal fore arm• Palmar cutaneous branch----skin on lateral side of palm
- 4) Branches in palm• Muscle of thenar eminence• First 2 lumbricals • Skin of palmar surface of lateral 3 ½ fingers
What are the features of median nerve injury at elbow?
- Cause:• Supracondylar fracture of humerus
- Motor loss• Loss of pronator of forearm• Loss of long flexors of wrist and fingers except medial half of flexor digitorum profundus and flexor carpi ulnaris• Loss of flexion of terminal phalanx of thumb• Loss of thenar muscles (wasted)
- Deformity:Forearm ----supinated, Wrist----flexion is weak accompanied by adduction, Fingers----no flexion of interphalangeal joint of index and middle Thumb---flexion, abduction and opposition is lost
- APE’S HAND----thumb laterally rotated adducted and thenar eminence flattened
- Sensory loss• Lateral side of palm• Palmar surface of lateral 3 ½ fingers• Distal part of dorsal surface of lateral 3 ½ fingers
What is the feature of INJURY TO MEDIAN NERVE AT WRIST?
- Most common injury of median nerve
- Causes• Due to penetrating injuries or stab wound at the wrist
- Motor loss• Muscle of thenar eminence• First two lumbricals
- Deformity APE’S HAND
- Sensory loss • Same as in elbow lesion
What are the features of NJURY TO MEDIAN NERVE IN CARPAL TUNNEL?
- Passage of long flexor tendon and median nerve
- Syndrome is caused by compression of median nerve due t o reduced size of canal
- Causes• Inflammation of retinaculum• Arthritis of carpal bones• Inflammation of synovial sheaths of flexor tendons
- Sensory and motor Loss:• Pain and paraesthesia of lateral one and half finger• Weakness of thenar muscle
What are the features of ulnar nerve?
- Arise from medial cord in axilla
- Descends between axillary artery and vein
- In anterior compartment of arm on medial side of brachial artery
- Pierces medial intermuscular septum to enter in posterior compartment
- At elbow lies behind medial epicondyle
- Enter forearm between 2 heads of flexor carpi ulnaris
- At wrist between tendons of flexor carpi ulnaris and digitorum profundus
- Enter palm superficial to flexor retinaculum
What are the branches of ulnar nerve?
- Branches in axilla or arm• No branches
- Branches in proximal forearm• Nerve to FCU• Medial half of flexor digitorum profundus
- Branches in distal forearm• Palmar cutaneous branch -----skin of hypothenar eminence• Posterior cutaneous branch----skin of medial third of dorsum of hand and dorsal side of medial one and half finger
- Branches in palm• Superficial branch of ulnar---- skin of palmar surface of medial one and half finger• Deep branch of ulnar• All small muscles of hand except of thenar muscles and first 2 lumbricals
What are the features of ulnar nerve injury at elbow?
- Most commonly injured at this site
- Cause• Fracture of medial epicondyle
- Motor loss• FCU and medial half of flexor digitorum profundus• Small muscle of hand are paralyzed except thenar muscles and first 2 lumbricals
- Deformity• Wasting of ulnar border of forearm• Terminal phalanges of little and ring finger can not be flexed• Inability to abduct and adduct fingers• Loss of adduction of thumb• Forment’s sign flexion of terminal phalanx of thumb while attempting adduct the thumb in ulnar nerve palsy•
- CLAW HAND: a. Metacarpophalangeal joints of fourth and fifth finger are hyper extended, b. Interphlangeal joint of fourth and fifth fingers are flexed • Flattening of hypothenar eminence• Hollowing between metacarpals on dorsum of hand due to paralysis of dorsal interossei
- Sensory loss• Anterior and posterior surfaces of medial half of hand and medial one and half fingers
What are the features of ulnar nerve injury at wrist?
- ULNAR NERVE INJURY AT WRIST• Due to superficial position
- Causes• Penetrating wounds
- Motor loss• Small muscles of hand except those of thenar eminence and first 2 lumbricals
- Deformity• Claw hand more prominent
- Sensory loss• On the medial side of palm and palmar and dorsal surface of 1 ½ fingers• Sensation on posterior medial surface of hand is intact