Neurology Flashcards
CN 3 palsy features
- eye down and out, pupil dilated
- failure of addiction, elevation, depression, and ptosis of eyelid
CN IV palsy features
- head tilt
- can’t intort eye
- on adduction, eye elevates
Causes of CN IV palsy
- head injury
- DM
Causes of CN VI palsy
Location: CN6 nucleus in pons
- HTN
- DM
- raised ICP
- pontine stroke or bleed
- nasopharyngeal cancer
Features of INO
- one eye fails to adduct, the other eye: nystagmus
Causes of INO
- lesion of median longitudinal fasciculus
- unilateral INO: stroke
- bilateral INO: MS
Decreased visual acuity, with RAPD
Lesion at anterior visual system: eye or retina or optic nerve
- optic neuropathy:
- inflammatory: optic neuritis
- infiltrative: sarcoidosis, lymphoma
- trauma
- compression
- ischemia: GCA
Cause of bitemporal hemianopia
Optic chasm lesion
- pituitary tumor; look for signs of hypopituitarism or acromegaly
Causes of homonymous hemianopia
Location of lesion: behind optic chiasm
- stroke
- tumor
Homonymous hemianopia with sparing of central vision. Where is the lesion?
Occipital lobe
Upper homonymous quadrantanopia: where is the lesion?
Temporal lobe optic radiation
Lower homonymous hemianopia: where is the lesion?
Parietal love optic radiation
Peripheral nystagmus beats away or towards lesion?
Away from side of lesion
Vertical nystagmus central or peripheral?
Central duh
Horner syndrome causes:
1st order: tumor, stroke: brain stem, hypothalamus
2nd order: apical lung tumor, mediastinal tumor
3rd order: skull base lesions, trauma
Causes of 3rd nerve palsy
- posterior communicating artery aneurysm
- chronic meningitis
- raised ICP
- cavernous sinus lesion (would involve CN V)
- DM
- HTN
How to test median nerve function?
- thumb abduction
- thumb flexion
- index finger flexion
- median nerve distribution sensation
What are features of ulnar nerve lesion?
Loss of:
- finger abduction
- little finger flexion
- ulnar nerve distribution sensation
- claw hand 4th, 5th fingers
What are features of radial nerve lesion?
Loss of:
- finger extension
- wrist extension
- elbow E (triceps), if lesion above spiral groove
- brachioradialis
- sensation anatomical snuff box
How to test C5-C6 nerve root?
- deltoid: shoulder abduction
- biceps and brachioradialis
- biceps and supinator jerks
- C5/C6 dermatome
How to test C7-C8 nerve root?
Finger flexion and extension
Triceps: elbow extension
Triceps jerk
C7-C8 dermatome
What are differentials for mainly motor neuropathy?
- GBS / CIDP
- hereditary: CMT
- DM
- lead poisoning
- polio
What are differentials for sensory neuropathy?
- DM
- malignancy ?paraneoplastic
- b12 deficiency
What are causes of peripheral neuropathy?
- metabolic: DM, hypothyroidism
- hereditary
- alcohol
- GBS
- drugs/toxins: isoniazid, cisplatin, phenytoin
- rheum: RA, SLE, Vasculitis
What are causes of mononeuritis multiplex?
- DM
- connective tissue disease: SLE, RA
- compressive neuropathy
- sarcoidosis
What are the features of CMT?
- pets cavus
- distal muscle atrophy
- absent reflexes
- minimal to no sensory loss
- thickened nerves
Causes of hand wasting?
Nerve: - median, ulnar nerve lesions - plexus lesion Anterior horn cell disease: - MND - polio Myopathy: - myotonic dystrophy Spinal cord: - syringomyelia, cervical spondylosis, tumour
How to differentiate the causes of foot drop?
- Peroneal nerve: lose Dorsi F and eversion only
- L5 radiculopathy: lose Dorsi F, eversion, AND inversion
- sciatic nerve: foot can’t do anything, loses plantar flexion too
Feature of sciatic nerve lesion?
L4/L5/S1/S2
- weak knee F
- loss of power below knees
- absent ankle jerk, no plantar response
- sensory loss posterior thigh and below knee
Spinal cord lesion causes?
- cord compression: spondylosis, abscess, tumour
- transverse myelitis
- MS
- intrinsic cord lesion: infarction, syrinx
What are features of subacute combined degeneration of cord (B12 deficiency)?
- upper motor neuron signs in lower limbs (increased tone, UMN pattern weakness, upgoing plantar)
- but absent ankle jerks and sometimes loss of knee jerk.
- sensory neuropathy: vibration, proprioception
What are the features of cord hemisection (Brown Sequard)?
Motor:
- Ipsilateral UMN signs below lesion
- ipsilateral LMN signs AT level of lesion
Sensory:
- ipsilateral loss of vibration, position
- contralateral loss of pain, temperature
What are causes of Brown-Sequard?
- MS
- glioma
- trauma
- myelitis
- post radiation myelopathy
What are some causes of muscle weakness?
Myopathy:
- polymyositis, Dermatomyositis
- endocrine: hypo/hyperthyroidism, Cushings, hypopituitarism
- drugs: steroids
- hereditary: muscular dystrophy (only in males)
NMJ: myasthenia, lambert-eaton
Neurogenic: MND, polyradiculopathy (I.e. spinal stenosis, leptomeningeal disease, tumors, diabetic amyotrophic)
What tests for myopathy?
- CK
- EMG
- muscle biopsy
What are side effects of dopamine agonists in Parkinson’s?
- impulsivity: gambling, hyper sexuality, shopping
- headache
- nausea/vomiting
- fatigue
What are some causes of Horner’s syndrome?
- apical lung mass or infection
- neck: thyroid mass, trauma
- carotid artery aneurysm
- brainstem lesions
Clinical features of Horner’s syndrome?
- ptosis
- pupil constricted
- loss of sweating forehead
- hoarse voice
What is lateral medullary syndrome and what are the clinical features?
Stroke or lesion at lateral medulla
- nystagmus to side of lesion
- ipsilateral pain loss
- ipsilateral cerebellar signs
- contralateral pain/sensory loss in limbs
What are causes of optic neuropathy?
- MS
- metabolic: B12 deficiency
- DM
- temporal arteritis
- infiltrative: lymphoma, sarcoidosis
What causes a 3rd CN Palsy with sparing of the pupil?
- diabeetus
- arteritis
- MG - can mimic CN palsy
What are causes of CN3 palsy?
- posterior communicating artery aneurysm
- tumour: raised ICP
- DM
- Trauma
- cavernous sinus lesion
What nerve lesion causes Abductor Pollicus Brevis (APB) wasting?
Median nerve
What nerve lesion causes Abductor Digiti Minimi (ADM) and 1st dorsal interosseous wasting?
Ulnar nerve
What lesion causes thumb abductor weakness?
Median nerve at carpal tunnel
What lesion causes thumb abductor, thumb flexion, and index finger weakness?
Median nerve at elbow
What lesion causes isolated finger abduction weakness
Ulnar nerve at elbow
What causes wasting, weak finger extensors, finger flexors, and triceps?
C7, C8, T1 root or plexus lesion
What causes flaccid paralysis of entire arm, with wasting, areflexia, sensory loss to one arm?
Avulsion of all roots of brachial plexus (i.e. trauma)
What causes wasting of one hand, loss of reflexes in arm, and dissociated sensory loss (loss of pinprick, but normal light touch) in half cape distribution?
Lesion of cervical and upper thoracic cord (syringomyelia, tumours)
What causes wasting of both hands, and spastic weakness in legs?
C8-T1 cord lesion: trauma, tumour
What causes generalised muscle weakness and wasting, fasiculations, hyper-reflexia, and normal sensation?
Motor neuron disease
What causes distal wasting and weakness of all 4 limbs, areflexia, and a glove/stocking sensation loss?
Peripheral neuropathy i.e. DM, inherited
What causes distal wasting, weakness of all four limbs, hyporeflexia, baldness, ptosis and cataracts
Myotonic dystrophy
What causes weakness of brachioradialis, wrist extension, finger extension? Normal triceps power. With loss of brachioradialis reflex, and sensory loss of snuff box?
Radial nerve lesion at spiral groove
What causes weak triceps, finger extensors, and finger flexors? Loss of triceps reflex?
C7-C8 root or plexus lesion
What causes increased tone, generalised weakness of muscles of upper limb in deltoid, triceps, wrist E, finger E? Hypereflexia of UL?
Corticospinal lesion
What causes weakness of detloid only? Biceps and brachioradialis power normal. Sensation loss over deltoid.
Axillary nerve lesion.
What causes :
- weakness of deltoid, biceps, and brachioradialis? Absent biceps and brachioradialis reflex.
- Triceps reflex increased
- Increased lower limb reflexes
C5-C6 cord lesion
What causes:
- weakness of deltoid, biceps, and brachioradialis
- absent biceps and brachioradialis reflex
- normal triceps and leg reflexes
C5-C6 root or plexus lesion
What causes:
- weakness of all muscles in one arm
- absent reflexes
- C5 to T1 sensory loss
Brachial plexus lesion
What causes:
- weakness of all muscles in one arm
- hyperreflexia
UMN/hemiparesis
What causes:
- proximal weakness both arms and both legs
- normal or reduced reflexes
- normal sensation
- polymyositis/dermatomyositis
- Myasthenia Gravis
What causes:
- selective proximal weakness of arms and legs
- muscular dystrophy
- spinal muscular atrophy
- inclusion body myositis
Where is the lesion:
- weakness hip F, knee E
- normal hip add
- absent knee jerk
- femoral nerve lesion
Where is the lesion:
- weakness hip F, knee E, hip adduction
- absent knee jerk
L2/3/4 root or plexus lesion: tumour, amyotrophy
Where is the lesion:
- unilateral weakness Hip F, Knee F, Dorsi F, eversion
- increased tone and reflexes
UMN/corticospinal lesion
Where is the lesion:
- bilateral weakness hip F, knee F, ankle dorsi F, eversion
- increased tone and reflexes
spinal cord lesion
Where is the lesion:
- proximal weakness
- normal or reduced reflexes
- myopathy: muscular dystrophy/polymositis
- myasthenia gravis
Where is the lesion:
- proximal weakness
- absent reflexes
- spinal muscular atrophy
- GBS
Where is the lesion:
- weak dorsi F and eversion
- common peroneal nerve lesion (with lateral lower leg sensation loss)
Where is the lesion:
- weak dorsi F, eversion, inversion
- L4/5 root or plexus lesion
Where is the lesion:
- weak dorsi F, eversion, inversion, and plantar F
- sciatic nerve lesion
DDx: trauma, vasculitis, tumour
Where is the lesion:
- distal weakness both legs
- areflexia
- glove/stocking sensory loss
- peripheral neuropathy (DDx: - metabolic: DM, hypothyroidism - hereditary - alcohol - GBS - drugs/toxins: isoniazid, cisplatin, phenytoin - rheum: RA, SLE, Vasculitis)
Where is the lesion:
- wasting, fasiculations
- hyper-reflexia
- normal sensation
- MND
Where is the lesion:
- weak hip F, knee F, dorsi F, eversion
- tone increased
- brisk reflexes
- UMN/corticospinal
Where is the lesion:
- bilateral weakness hip F, knee F, dorsi F, eversion
- tone increased
- brisk reflexes
- spinal cord lesion
What does a positive Romberg’s mean?
- ataxia from loss of proprioception/sensation, such as: diabetic neuropathy, sensory neuropathy, spinocerebellar degenration, subacute combined degeneration of cord, MS
- NOT cerebellar ataxia
What does unilateral high stepping gait suggest?
- unilateral foot drop
What does bilateral high stepping gait suggest?
- bilateral foot drop:
DDX:
1) peripheral neuropathy i.e. CMT
2) MND
What does wide based and high stepping gait suggest?
sensory ataxia
DDx: diabetic neuropathy, sensory neuropathy, spinocerebellar degenration, subacute combined
Causes of waddling gait
- weakness of hip abduction
- DDx: myopathy, OA hips
- Trendelenberg “sound side sags”
DDx of circumduction gait
- hemiparesis: stroke
DDx of bilateral circumducting gait
- spastic paraparesis/scissoring gait
DDx: cerebral palsy, hereditary spastic paraplegia, MS, cervical spondylosis
What does a Parkinson’s gait look like?
- small shuffling steps
- turning takes several steps
- normal/narrow based gait
- decreased arm swing
- positive pull test
Shuffling small steps, several steps to turn, broad based gait
- NPH
- dementia
What causes broad based irregular/ataxic gait?
- cerebellar disturbance
- stagger to side of lesion
What causes facial weakness, with sparing of frontalis and eyelid closure?
UMN/stroke contralateral cerebral hemisphere
What causes weakness of all muscles on one side of face?
LMN DDx: - Bell's Palsy (sensation normal) - lesion of facial nucleus (has CN VI palsy as well) - acoustic neuroma - infection within facial nerve canal
Bilateral facial weakness
- GBS
- myotonic dystrophy
- MG
- Bilat UMN: multi-lacunar stroke or MND
In facial weakness, if pupils spared, usually means muscle or NMJ problem
…
What are the features of CMT?
- Pes cavus (high arches, hammer toes)
- Distal muscle atrophy (champagne bottle legs)
- Absent reflexes
- No or only slight snesory loss
- Thickened nerves
- optic atrophy (RAPD)
What are some causes of foot drop?
- common peroneal nerve palsy
- sciatic nerve palsy
- Lumbosaccral plexus lesion
- L4/5 nerve root lesion
- peripheral motor neuropathy
- distal myopathy
- MND
Shoulder abduction:
- Muscle: ??
- Nerve root: ??
- Peripheral nerve: ??
Muscle: deltoid
Nerve Root: C5/C6
Peripheral Nerve: axillary nerve
Elbow E: Which: - Muscle - Nerve Root - Peripheral Nerve
Muscle: Triceps
Nerve Root: C7/C8
Peripheral Nerve: radial
Elbow F: Which: - Muscle - Nerve Root - Peripheral Nerve
Muscle: Biceps
Nerve Root: C5/C6
Peripheral Nerve: musculocutaneous
Wrist E: Which: - Muscle - Nerve Root - Peripheral Nerve
Muscle: extensor carpi ulnaris
Nerve Root: C7/C8
Peripheral Nerve: branch of radial
Wrist F: Which: - Muscle - Nerve Root - Peripheral Nerve
Muscle: flexor carpi radialis
Nerve Root: C6/C7
Peripheral Nerve: median
Finger E: Which: - Muscle - Nerve Root - Peripheral Nerve
Muscle: extensor digitorum
Root: C7/C8
Nerve: Radial
Finger abduction: Which: - Muscle - Nerve Root - Peripheral Nerve
Muscle: dorsal interossei
Root: C8/T1
Nerve: Ulnar
What are the features of myotonic dystrophy?
Inspection: - frontal baldness - triangular facies - wasting of temporalis, masseter, sternomastoid - partial ptosis Neck: - weak neck flexion Upper limbs: - grip myotonia (shake hands) - percussion myotonia (tap over thenar eminence) - wasting and weakness (esp. forearm) - usually only mild sensory loss Chest: - gynecomastia Testicular atrophy Urinalysis: glycosuria Cardiomyopathy
What are the features of lateral medullary syndrome?
Occlusion of PICA or branches of vertebral artery; lateral medulla infarcts:
- vomiting/vertigo/nystagmus
- ipsilateral cerebellar signs
- ipsilateral dimished gag reflex
- ipsilateral Horner’s
- ipsilateral face loss of pain/temp
- contralateral loss of pain/temperature
What are some causes of Parkinsonism?
- idiopathic PD
- drugs drugs drugs (metopclopramide, antipsychotics)
- Wilson’s disease
- Parkinson’s Plus: PSP, MSA
What are causes of UMN facial weakness?
- brain: infarct, tumour, bleed
- pons: MS, MND, infarct, tumour
What are causes of LMN facial weakness?
Most common: Bell's palsy Cerebello-pontine angle: - acoustic neuroma - meningioma - tumour, mets Facial nerve canal: - Bell's - zoster (Ramsay Hunt) - tumour, trauma Parotid: sarcoidosis
What is the differential for bilateral proximal muscle weakness?
- neuropathy
- myopathy
- MND
- MG/Lambert Eaton