Prof Uma Flashcards
(224 cards)
signs to look for to differentiate between UMN and LMN?
Wasting, tone, reflexes, clonus, Babinski
Bilateral UL and LL weakness -> next step?
UMN or LMN?
Bilateral UL and LL weakness -> LMN pattern of weakness -> what next?
Distal or proximal weakness
Bilateral UL and LL weakness -> LMN pattern of weakness -> distal weakness -> what next?
Sensation normal or abnormal?
Bilateral UL and LL weakness -> LMN pattern of weakness -> distal weakness -> normal sensation
Potential causes:
1) motor neuron disease: pure motor atrophy, polio
2) pure motor peripheral neuropathy: MMN
3) distal myopathy: myotonic dystrophy, inclusion body myositis
Bilateral UL and LL weakness -> LMN pattern of weakness -> distal weakness -> sensation abnormal -> what next?
Glove and stocking numbness
Vs
Patchy numbness
Bilateral UL and LL weakness -> LMN pattern of weakness -> distal weakness -> sensation abnormal -> glove and stocking numbness
Causes?
Peripheral neuropathy
Bilateral UL and LL weakness -> LMN pattern of weakness -> distal weakness -> sensation abnormal -> patchy numbness
Potential causes?
In distribution of peripheral nerve:
Mononeuritis multiplex
Mono-neuropathies
Multiple mononeuropathies: Vasculitic neuropathy, Leprosy, multiple entrapment neuropathy
Dermatomal:
Radiculopathy
Bilateral UL and LL weakness -> LMN pattern of weakness -> proximal weakness -> what next?
Sensation normal or not?
Bilateral UL and LL weakness -> LMN pattern of weakness -> proximal weakness -> sensation normal
Potential causes?
1) myopathy
2) myasthenia Gravis (fatiguable, bulbar and ocular weakness)
3) motor neuron disease: spinal muscular atrophy, progressive muscular atrophy. Polio (fasciculations, bulbar weakness)
Bilateral UL and LL weakness -> LMN pattern of weakness -> proximal weakness -> sensation abnormal
Potential causes?
If UL is normal, Lumbosacro plexo/radiculopathy
If LL normal or unilateral, c5-6 radiculopathy or brachial plexopathy
If UL and LL affected: GBS/ CIDP
Causes of myopathies?
Congenital/Inherited: dystrophy (Myotonic dystrophy, Fascioscapulohumeral dystrophy, Becker’s, limb-girdle muscular dystrophy)
Metabolic/ Endocrine: hypo/hyperthyroidism, Cushing’s syndrome, Vit D Deficiency
Neoplastic/ paraneoplastic: dermatomyositis
Inflammatory/ infectious: polymyositis, dermatomyositis, myositis
Human activity (Iatrogenic/ toxin/ trauma): Drugs-statin, fenofibrate, colchicine
Causes of diffuse polyneuropathy?
Congenital: Charcot Marie tooth, amyloidosis
Metabolic/ endocrine: DM, b12 deficiency, renal failure, hypothyroidism
Neoplastic/ paraneoplastic: anti Hu antibody associated sensory neuropathy
Inflammatory/ infectious: GBS/ CIDP, sjogrens, HIV
Drugs/ iatrogenic/ trauma: isoniazid, vincristine, cisplatin, alcohol/ lead
If multiple mononeuropathy in UL and LL ? Causes
Vasculitis neuropathy
Leprosy
Multiple entrapment neuropathy
How to differentiate between L5 radiculopathy, sciatic neuropathy and peroneal neuropathy?
All 3 have:
Weak Ankle dorsiflexion, eversion
Numbness on dorsum of foot
Both sciatic neuropathy and L5 radiculopathy:
+ Weak inversion
Sciatic neuropathy alone:
Ankle reflex absent or weak
Weak ankle plantarflexion
Numb sole
L5 radiculopathy alone;
Weak hip abduction, internal rotation and extension
How to differentiate between C8 radiculopathy and ulnar mononeuropathy?
Both have:
Weak finger abduction and flexion
Weak thumb adduction
Numb 5th digit
Ulnar neuropathy:
Split ring finger sensory loss
froments sign +
C8 radiculopathy:
Weak thumb abduction, flexion
Weak finger extension at MCPJ
How to differentiate between C7 radiculopathy and radial mononeuropathy?
Both:
- triceps reflex weak/ absent
- weak elbow extension, wrist extension, finger MCPJ extension
- numb dorsum of hand
Radial mononeuropathy:
Brachioradialis bulk and strength affected
C7 radiculopathy:
+/- mild weakness of forearm pronation
Finger extension at interphalangeal joint weak
How to differentiate between femoral neuropathy vs L4 radiculopathy?
Both have:
- weak knee reflex
- weak knee extension
- numb medial shin
Femoral neuropathy only:
Weak hip flexion
L4 radiculopathy:
Weak hip adduction
Adductor reflex affected
Bilateral LL weakness -> UMN pattern weakness -> what next?
Assess sensation
Bilateral LL weakness -> UMN pattern weakness -> normal sensation
Causes?
Motor neuron disease: look for wasted tongue with fasciculations, mixture of UMN/LMN signs
Subcortical:
Binswanger disease, multiple strokes
Cortical: parasagittal lesions (meningioma)
Hereditary spastic paraplegia
Bilateral LL weakness -> UMN pattern weakness -> abnormal sensation
Causes
Means pathology at spinal cord
-> use reflex and power to localise segment of spinal cord involved
Glove and stocking:
Chronic cervical myelopathy
Medical myelopathy
Sensory level:
Myelopathy/ myelitis (fairly acute)
Approach to cranial neuropathy?
4 different classifications
ie. once you notice cranial nerve pathology, work along this pathway to neurolocalise
Brainstem lesions: check for pronator drift, dysdiadochokinesia, babinski normal
Cranial nerve clubs
Meningeal and skull base disease e.g. TB meningitis, NPC: signs of meningism, neck stiffness. any epistaxis? any cervical lymphadenopathy
Peripheral neuropathy: GBS and its variants
Cranial neuropathy due to brainstem lesion
Causes
Except cranial nerves 1 & 2 which originate from cerebrum, CN 3-12 originate from brainstem
Midbrain: 3, 4 (look for drowsiness, vertical gaze abnormalities, cerebellar and pyramidal signs)
Pons: 5, 6, 7, 8 (look for horizontal gaze abnormalities, pyramidal, cerebellar signs, drowsiness
Medulla: 9-12
Look for horners, pyramidal, cerebellar signs, drowsiness
Cranial neuropathies
Cranial nerve “clubs”
Cavernous sinus
Orbital apex
Cerebellopontine angle
Jugular foramen