NEURO: Part 9 Flashcards
WHat nerves contributes to the median nerve
C5-7, C8 + T1
What muscles of the forearm are innervated by the median nerve
- Palmaris longus
- Flexor capri radialis
- Flexor digitorum superficialis
What does the anterior interosseous branch of the median nerve supply
- Flexor policis longus
- Lateral half of flexor digitorum profundus
- Pronator quadratus
What does the palmer cutaenrous branch of the median nerve supply
Sensory innervation to thenar eminence of palm
Median nerve innervation of the hand
- Flexor digitorum superficialis
- Flexor digitorum profundus
- Flexor pollicis longus
Recurrent branch:
- opponens pollicis
- Abductor pollicis brevis
- Flexor pollicis permis
What do the cutaneous branch of the median nerve supply
- Lateral 3 and a half
What is Anterior interosseous syndrome
—- Reminder —–
1. Flexor policis longus
2. Lateral half of flexor digitorum profundus
3. Pronator quadratus
—————————-
Loss of pronation of forearm
Loss of flexion of radial half of digits and thumb
NO SENSORY LOSS
What causes anterior interosseous syndrome
Tight Cast
Forearm bone fracture
Result of damaging the wrist
MOTOR DEFICIT:
- Weakness in flexion of the radial half of digits and thumb
- Loss of abduction and opposition of the thumb
APE HAND DEFORMITY seen (hyperextension of index and thumb)
Benediction sign seen
SENSORY:
Loss of sensation in lateral 3 1/2 digits including nail beds
What is the benediction sign
Patients can flex all fingers EXCEPT the index finger
Innervation of the lubricals
Lateral two = lumbrical
Medial two = ulnar
What doe the ulnar nerve supply when it branch sin the forearm
- Medial half of flexor digitorum profundus
- Flexor carpi lunaris
- Medial half sensory sensation to digits (1 and a half)
What does the ulnar supply in the hand when it branches
- Abductor digiti minimi
- Flexor digiti minimi
- Opponens digiti minimi
Roots of the ulnar nerve
C7-T1
What causes damage commonly to the ulnar nerve at there elbow
- Cubital tunnel syndrome
2. Fracture of medial epicondyle
Clinical presentation of ulnar damage at the elbow
MOTOR DEFICIT:
1. Weakness in flexion of hand AT THE WRIST
2. Loss of flexion in ulnar half of digits
3. CLAW HAND deformity when hand is at rest
4. Weakness of adduction o the thumb
5. Interossei muscle wasting means patient can’t do good luck sign
——SENSORY——–
Loss of sensation and paraesthesiae in ulnar half of palm and back of hand
Medial 1 and 1/2 digits on both palmar and dorsal aspects of the hand
How do we assess weakness of adduction o the thumb
Look for FROMENT’s Sign
What is Froment’s sign
Difficult maintaining a hold on an object (digits minimi oppenens is not working so will try compensate by flexing policies longs more)
What usually causes damage to ulnar nerve at the wrist
- WOUNDS
Clinical presentation of ulnar damage at the wrist
- —-MOTOR_—–
1. Loss of flexion in ulnar half of the digits
1. CLAW HAND deformity when hand is at rest (more prominent than in elbow)
——SENSORY——-
Loss of sensation and paraesthesiae in ulnar half of palm, medial 1 1/2 digits and the DORSAL is spared
Why is CLAW HAND DEFORMITY more prominent in wrist injuries to the ulnar
Ulnar half of flexor digitorum profundus is not affected so they pull interphalangeal joints of 4th and 5th digit into flexion whilst the lateral three digits are straight
Why is the dorsal part of the hand spared in wrist damage to ulnar nerve
Because the posterior cutaneous branch of the ulnar nerve is given off higher up the forearm
How is Ulnar nerve palsy treated
Night splint and rest
Roots of the radial nerve
C5 - T1
What does the radial nerve supply in the arm
- Brachialis
- Brachioradialis
- Extensory carpi radialis longus
- Suppinators
SENSORY: Supplies skin at back of the arm
What does the radial nerve supply in the forearm
Forms the posterior interosseous nerve:
- Extensor digitorum
- Extensor digit minimi
- Extensor carpi lunaris
- Abductor pollicis longus
- Extensor pollicis brevis
- Extensor pollicis longus
- Extensor indicis
Common causes of injury to the radial nerve at the axilla
- Saturday NIGHT PALSY
2. Crutch palsy
What is Saturday night palsy
Caused by:
Another individual sleeping on one’s arm overnight
Falling asleep with one’ arm hanging over arm rest chair compressing nerve
Squash
Common injury to the radial nerve at the mid-arm
- MID-SHAFT humeral fracture
Clinical presentation of radial nerve damage at th mid-arm
- Weakness of supination and loss of hand extension and fingers (test by flexing elbows and arm pronated)
- Presence of WRIST DROP due to inability to extend hand and fingers
——-Sensory———
Loss of sensation in posterior forearm
Radial dorsal of the hand
Dorsal radial 3 and a half digits
Causes of damage to the brachial plexus
- Trauma
- Radiotherapy
- Prolongues wearing of heavy rucksack
- Neuralgic amyotrophy
- Thoracic outlet compression
Clinical presentation of brachial plexus
- Pain/paraesthesiae and weakness in affected arm in variable distribution
Clinical presentation of phrenic palsy
ORTHOPNOEA
Raised hemidiaphragm on CXR
What causes phrenic palsy
- Lung cancer
- Myeloma
- Thymoma
- Cervical spondylosis
- Phrenic nucleus lesion in MS
- Thoracic surgery
- HIV
- Muscular dystrophy
Roots of lateral cutaneous nerve of the thigh
L2 and L3
Clinical presentation of lateral cutaneous nerve palsy
Anterior-lateral burning of thigh from entrapment under inguinal ligament
What causes sciatic nerve palsy
- Pelvic tumours
2. Fractures to pelvis or femur
Clinical presentation of sciatic nerve palsy
FOOT DROP
Loss of sensation to lateral skin below knee
Where does the common perineal nerve originate from
Sciatic nerve just above the knee
Why does common perineal nerve get injured
Winds round fibular head so sitting cross-legged will do it
Clinical presentation of common perineal nerve palsy
FOOT DROP
WEAK ANKLE DORSIFLEXION/EVERSION
SENSORY LOSS OF dorsal of foot
What does the common perineal nerve supply
Muscles in anterior and lateral compartments of the leg
What doe the tibial branch of the sciatic supply
Posterior compartment and sole of the foot (plantar)
Clinical presentation of tibial palsy
Inability to stand on tiptoes, invert foot or flex toes
SENSORY LOSS OF SOLES
What are polyneuropathies
- SYMMETRICAL Disorders of peripheral or cranial nerves
Where does polyneuropathy usually begin
Hands and feet
Spreads to arms and legs
What three ways can we classify polyneuropathies
- Distal axonopathy
- Myelinopathy (loss of Schwann cells - Guillain-Barre syndrome)
- Neuropathy (caused by disease)
Course: Acute or chronic
Function: Sensory, mixed or motor
Pathology: Demyelination etc
What usually causes distal axonopathies
Metabolic diseases:
Diabetes
Kidney failure
Connective tissue disease
What polyneuropathies cause motor problems
- Guillain-Barre syndrome
- Lead poisoning
- Charcot-Marie-Tooth syndrome
What polyneuropathies cause sensory problems
- Diabetes mellitus
- Renal failure
- Leprosy
METABOILC
Overview of causes of polyneuropathies
- Metabolic: Diabetes mellitus, renal failure, hypothyroidism, hypoglycaemia
- Vasculitides: Polyarteritis nodosa, rheumatoid arthritis, wegener’s granulamatosis
- Malignancy: Paraneoplastic syndromes, polycythaemia rubra vera
- Inflammatory: Guillain-Barre syndrome, sarcoidosis
- Infections: Leprosy, HIV, syphilis, lyme disease
- Nutritional: Decreased; vit B12,B1,E,B6 & folate
- Inherited syndromes: Charcot-marie-tooth, porphyria
- Drugs/toxins: Lead, arsenic, alcohol, vincristine, cisplatin, metronidazole
How is polyneuropathy diagnosed
- Electrophoresis of serum proteins
- NCS
- Urinalysis
- Serum Creatinine Kinase
- Antibody testing
- Nerve biopsy
- HISTORY taking for course, symptoms etc before the event (ARthalgia from connective tissue, weight loss in cancer and vomiting in Guillain-Barre syndrome)
EXAMINE OTHER SYSTEMS
What condition is probable upon examining a palpable thickened nerve
LEPROSY or CHARCOT-MARIE-TOOTh
Sensory clinical presentation of polyneuropathies
- NUMBERNESS, pins and needles
- Affects extremities (glove and stocking distribution)
- Difficulties handling objects like buttons
- Signs of trauma but unaware of it
- Diabetic and alcoholic neuropathies are PAINFUL
Motor clinical presentations of polyneuropathies
- Weak hands
- Difficulty walking
- Difficulty breathing
- LMN lesion apparent (foot or wrist drops and hyporeflexia)
What causes brainstem compression
- tumour
- MS
- Trauma
- Aneurysm
- Vertebral artery dissection resulting in infarction
- Infection: cerebellar abscess from ear
Clinical presentation of oculomotor palsy
- Ptosis (dropping eyelids - levator palpebrae superioris)
- Fixed dilated pupil
- Eye down and out
- DIPLOPIA as rectus muscles
What is nucleus does parasympathetic outflow from the oculomotor nerve to the pupillary sphincter called
EDINGER-WESTPHAL nucleus
What causes oculomotor palsy
- Raised ICP
- Diabetes
- Hypertension
- Giant cell arteritis
Clinical presentation of Trochlear palsy
- Innervates superior oblique muscle
Patient will tilt head to correct extortion - causes diplopia
Clinical presentation of Abducens palsy
INNERVATES lateral rectus muscle thus eyes will be adducted
Cross-eyed
Causes of abducens palsy
- MS
- Wenicke’s encephalopathy
- Pontine stroke - fixed small pupils + quadriparesis
What is CN 3,4,6 palsy
- Non functioning eye
Causes of 3,4,6 palsy
- Stroke
- Tumours
- Wernicke’s encephalopathy
Clinical presentation of Trigeminal palsy
- Jaw deviates to side of lesion
2. Loss of corneal reflex
Causes of trigeminal palsy
- Trigeminal neuralgia (PAIN not sensory loss)
- Herpes Zoster
- Nasopharyngeal cancer
Clinical presentation of facial palsy
Facial droop + weakness
Causes of facial palsy
- Bells palsy = dribbling outside of the mouth
- Fractures of petrous bones
- Middle ear infections
- Inflammation of parotid gland - which facial nerve pass through
Signs of vestibularcochlear palsy
- Hearing impairment
2. Vertigo and lack of balance
Causes of CN8 palsy
NERVE RUNS CLOSE TO THE BONE
- Affected by tumours in internal acoustic meatus
- Skull fracture
- Drug effects
- ear infection
CN9 and CN 10 palsy clinical presentation
- Gag reflex issues
- Swallowing issues
- Vocal issues
What causes glossopharyngeal and vagus palsy
- JUGULAR FORAMEN LESION
What is an autonomic neuropathy
- Sympathetic and parasympathetic neuropathies
Causes of autonomic neuropathy
- Diabetes mellitus
- HIV
- SLE
- Sjogren’s syndrome and Guillain-Barre
Clinical presentation of sympathetic neuropathy
- Postural hypotension - faints on standing
- Ejaculatory failure
- Reduced sweating
Clinical presentation of parasympathetic neuropathy
- Erectile dysfunction
- Constipation
- Nocturnal diarrhoea
- Urine retention
Polyneuropathy diagnsoes
- FBC
- Urinalysis
- CXR
- Lumbar puncture for specific neuropathies
FBC result for polyneuropathies
- ANA, ANCA and anti-CCP
How is Polyneuropathy treated
- TREAT CAUSE
- Foot care and shoe choices important in sensory
- Splint joint to prevent contractors (shortening and hardening of muscles and tendons) in prolonges paralysis
- Vasculitic causes - steroids and immunosuppressants
- ORAL AIMTRIPTYLINE or ORAL NOTRIPTYLINE
Where is pain felt in L2
- Across upper thigh
Where is weakness felt in L2
Hip flexion and adduction
L3 lesion pain
Lower thigh
Weakness in L3
Hip adduction and knee extension
L4 lesion pain
Across knee to medial malleolus
Weakness in L4
- Knee extension
Foot inversion
Dorsiflexion
Reflex affect din L3-L4
KNEE JERK
Pain in L5
Lateral shin to dosrum of foot and great toe
Weakness in L5 lesion
Hip extension
Abduction of hip
Knee flexion
foot and great toe dorsiflexion
Reflex affected in L5
Great toe jerk
S1 pain
Posterior calf to lateral foot and little toes
Weakness in S1 lesion
Knee flexion
Foot and toe plantar flexion
Foot eversion
Reflex los in S1
Ankle jerk