Summary Book Neurology Flashcards
What is the anatomical structures of the upper motor neuron pathway?
Cerebrum Hemispheres, Cerebellum, Brain Stem, Spinal Cord
What is the anatomical structures of the lower motor neuron pathway?
Anterior Horn Cell, Roots, Nerves, Neuromuscular Junction, Muscles
What neurological deficits are seen with issues with the cerebrum hemispheres?
Contralateral motor and sensory loss
What neurological deficits are seen with issues with the cerebellum?
Ipsilateral past-pointing and ataxia, as well as nystagmus
What neurological deficits are seen with issues with the brain stem?
Autonomic features, cranial nerve palsy, crossed limb signs
What neurological deficits are seen with issues with the spinal cord?
If cervical then bilateral upper and lower limbs affected, if thoracolumbar then bilateral lower limbs and if conus medullaris then bilateral lower limb with bladder and bowel dysfunction
What neurological deficits are seen with issues with the anterior horn cells?
Mixed upper and lower features in same region
What neurological deficits are seen with issues with the roots?
Ipsilateral, single limb involved with lower motor signs and often painful
What neurological deficits are seen with issues with the nerve plexus?
Ipsilateral, single limb, painful, not attributable to single nerve or level
What neurological deficits are seen with issues with the peripheral nerve?
Discrete deficit in one limb, one dermatome
What neurological deficits are seen with issues with the neuromuscular junction?
Generalised weakness, fatigable on repetitive testing, minimal sensory involvement
What neurological deficits are seen with issues with the muscles?
usually symmetrical in all limbs, sometimes with wasting, pattern usually proximal / limb girdle or distal
Conditions which affect the cerebrum hemispheres?
Stroke, MS, cerebral abscess, AVM, tumour
Conditions which affect the cerebellum?
Alcohol, stroke, AVM, tumour, paraneoplastic, sarcoidosis, multiple sclerosis, vitamin B12 deficiency, multiple system atrophy, congenital (spinocerebellar ataxia - dominant, Fredrich’s ataxia - recessive)
Conditions which affect the brain stem?
Stroke, MS/NMOSD, Bickerstaff
Conditions which affect the cervical spinal cord?
Trauma, MS/NMOSD, syringomyelia, cord compression, stroke
Conditions which affect the thoracolumbar spinal cord?
Trauma, compression, cord stroke, epidural abscess
Conditions which affect the conus medullaris?
Trauma, malignant cord compression, abscess
Conditions which affect the anterior horn cells?
MND, past polio
Conditions which affect the roots?
Degenerative disease, malignant compression
Conditions which affect the nerve plexus?
Trauma, malignant infiltration, paraneoplastic, inflammatory
Conditions which affect the peripheral nerve?
Extrinsic compression, metabolic, endocrine, toxic, drug, induced, vasculitis
Conditions which affect the neuromuscular junction?
Drug induced, MG, ES
Conditions which affect the muscles?
Myositis, muscular dystrophy, acquired myopathy, metabolic / mitochondrial myopathy
Upper motor neuron signs
Increased tone, clonus, increased reflexes, upgoing plantar
Lower motor neuron signs
Decreased tone and reflexes
Which cranial nerves enter the midbrain?
3 and 4
Which cranial nerves enter the pons?
5, 6, 7 and 8
Which cranial nerves enter the medulla?
9, 10, 11 and 12
Define Neuromyelitis Optica Spectrum Disorder
Inflammation of CN2, with painful eye movements, AQP4/MOG positive
Investigations for myopathies
Autoimmune screen + anti-Jo1 + biopsy of muscle
Causes of myopathies
Inflammatory (inclusion body myositis, sarcoidosis), Autoimmune (dermatomyositis, polymyositis), Metabolic (alcohol), Neoplastic, Degenerative (critical illness), Iatrogenic (steroids, statins), Congenital (Becker muscular dystrophy, Duchenne’s muscular dystrophy, myotonic dystrophy, facioscapulohumeral, limb girdle), Endocrine (acromegaly, thyroid issues, hypercortisolism)
Key sign of Duchenne’s muscular dystrophy
Calf pseudohypertrophy
Key signs of Muscular dystrophy
Myotonia, frontal bossing, ptosis
Two categories of peripheral neuropathy
Axonal (75%) and Demyelinating
Features of demyelinating peripheral neuropathy
Proximal predominant, neuropathic tremor, loss of proprioception, muscle wasting
General causes of peripheral neuropathy
Compression, diabetes, EtOH, uraemia, heavy metal, paraneoplastic, vitamin B12 deficit, congenital (charot mary tooth), iatrogenic (chemotherapy), infective (Guillain barre syndrome), inflammatory (sarcoidosis) and autoimmune (polyarteritis nodosa, systemic lupus erythematous, rheumatoid arthritis)
Causes of painful peripheral neuropathy
Vitamin B deficiency, heavy metal, paraneoplastic
Nerves of pectoralis
pectoral, C6, c7, c8
Nerves of tricep
radial, c6, c7, c8
Nerves of bicep
musculocutaneous, c5, c6
Nerves of brachioradialis
medial, c5, c6
Nerves of flexor digitorum
median and ulnar, c7, c8, c9
Nerves of adductor
obturator, l2, l3, l4
Nerves of knee - quadriceps femoris
femoral, l2, l3, ;4
Nerves of ankle - soleus / gastrocnemius
sciatic / tibial, s1, s2
Nerves of plantar
plantar
Causes of bilateral foot drop
motor neuron disease, hereditary neuropathy (charot marie tooth), hereditary motor dystrophy (myotonic)
Presentation of foot drop due to common peroneal
inversion preserved, sensory loss of dorsum of foot, reflexes normal
Presentation of foot drop due to L5 root nerve palsy
inversion preserved, sensory loss of dorsum of foot, reflexes normal, weakness of hip extension / knee flexion / inversion and eversion of ankle, decreased sensation of lateral calf and dorsum of foot
Presentation of foot drop due to sciatica (l4,5) (s1,2)
weakness of knee flexion and below knee, no ankle jerk, decreased sensation of lateral thigh and below knee
Presentation of foot drop due to femoral nerve palsy (l2,3,4)
weakness of knee extension and hip flexion, decreased sensation of inner thigh, decreased knee flexion
Presentation of motor neurone disease
upper and lower motor neurone signs in same region, initially asymmetric weakness confined to one segment, late signs of respiratory muscle weakness and cardiomyopathy, 25 to 40% cognitive features with frontotemporal behaviour and executive dysfunction, sensory exam unremarkable
Signs of pseudo bulbar disease
upper motor neuron, laryngospasms, trismus, brisk jaw jerk, small spastic tongue, slow + monotonous speech, emotional lability
Signs of bulbar disease
lower motor neuron, dysarthria, dysphagia, flaccid tongue, nasal twang
5 types of motor neuron disease syndromes
- Primary Lateral sclerosis (isolated UMN), 2. Progressive Muscular Atrophy (isolated LMN), 3. Progressive Bulbar Palsy (U + LMN disorder of cranial nerves), 4. Flail Arm / Leg Syndrome (progressive LMN weakness of proximal arm and distal leg), 5. ALS (amyotrophic) plus - plus atypical features (pain, ocular motility disturbance, tremor, extra-pyramidal symptoms (akathisia = urge to move, tardive dyskinesia = involuntary movement, dystonia = involuntary muscle contraction, parkinsonism), ataxia, autonomic dysfunction
Causes of acute mononeuritis multiplex
diabetes mellitus, vasculitis (systemic lupus erythematous, polyarteritis nodosa (medium vessel), rheumatoid arthritis)
Causes of chronic mononeuritis multiplex
infection (leprosy), multiple compressive neuropathies, sarcoidosis
Examination findings for myotonic dystrophy
hand (finger grip, percussion myotonia, repeated grip improves), face (frontal balding, cataracts, temporal-mandibular wasting, ptosis), neck (decreased muscle power and rom), cardio (conductive defects - PPM, displaced apex - cardiomyopathy), hypogonadism - gynaecomastia
First cranial nerve
olfactory - smell
Second cranial nerve
optic - vision
Third cranial nerve
Oculomotor - pupil constriction, accommodation, moves eyes up / down / medially, opens eyelids
Fourth cranial nerve
trochlear - supplies superior oblique muscle - moves eye down and inward
Fifth cranial nerve
trigeminal - sensation to face, muscles of mastication
Sixth cranial nerve
abducens - supplies lateral rectus - moves eye laterally
Seventh cranial nerve
facial - supplies muscles of facial expression, taste (anterior 2/3), closes eyelids
Eight cranial nerve
Vestibulocochlear - hearing and balance
Nineth cranial nerve
Glossopharyngeal - taste (posterior 1/3), swallowing and salivation
Tenth cranial nerve
Vagus - parasympathetic supply to eye / heart / gut / lungs / larynx (vocal cords)
Eleventh cranial nerve
Accessory - sternocleidomastoid and trapezius
Twelfth cranial nerve
Hypoglossal - tongue muscles
Causes of positive jaw jerk reflex (deviates to weakness)
Peripheral - shingles and Sjogren’s, Central - MS, cerebellopontine angle tumour (acoustic neuroma, meningioma)
Which nerves travel through the cerebellopontine angle?
5,6,7,8
Sounds for testing lip, tongue and vocal cord function
lip = me, tongue = la, vocal cord = ee
Causes of unilateral ptosis
congenital, Horner’s, myasthenia gravis, third nerve palsy
Causes of bilateral ptosis
congenital, Horner’s, myasthenia gravis, myotonic dystrophy, neurosyphilis
Sign of positive relative afferent pupillary defect
dilation with direct light
Retinal causes of relative afferent pupillary defect
infective (CMV, HSV), neoplastic (melanoma), structural (detachment), vascular (ischaemic diabetic retinopathy; or central artery or vein occlusion)
Optic causes of relative afferent pupillary defect
glaucoma, optic neuropathy
How does intranuclear ophthalmoplegia present?
dissociative conjugate eye movements - impaired adduction of ipsilateral eye and abduction nystagmus of contralateral eye
Causes of intranuclear ophthalmoplegia
lesion of medial longitudinal fasciculus (connects cn 3 and 6), drug toxicity (barbiturates, phenytoin, tricyclic antidepressants), inflammatory / demyelinating (multiple sclerosis), inflammatory / non-demyelinating (systemic lupus erythematous), neoplastic (brainstem tumour - pontine glioma), nutritional (wernickes encephalopathy), vascular (brainstem infarct). Medial medullary syndrome or cavernous sinus lesion (both CN 3,4,6). Miller fisher syndrome. Myasthenia gravis.
Presentation of second nerve palsy
Reduced visual acuity, visual field defect, asymmetric optic nerve function, abnormalities on fundoscopy
Causes of second nerve palsy
compressive (tumours - meningioma / glioma / pituitary adenoma; graves disease), hereditary (lebers hereditary optic neuropathy), infiltrative (tumours - carcinoma / lymphoma / myeloma; sarcoidosis), inflammatory / demyelinating (multiple sclerosis, neuromyelitis optica), inflammatory / non-demyelinating (autoimmune - bechets / GPA / SLE / systemic sclerosis; infection - lyme or syphilis), ischaemic - giant cell arteritis, nutritional - b12 deficiency, paraneoplastic - small cell and non-small cell lung cancer, traumatic, drugs (amiodarone, ethambutol, tobacco)
Anatomy of pupillary light reflex
cranial nerve 2 is the afferent / sensory limb, parasympathetic of cranial nerve 3 is the motor / efferent limb
Presentation of third nerve palsy
eye down and out
Causes of third nerve palsy
compression (posterior communicating artery aneurysm (dilated unreactive pupil)), ischaemic (diabetes, hypertension), brainstem tumours, temporal lobe coning (cerebral oedema with infection or infarction; or intracranial haemorrhage)
Presentation of fourth nerve palsy
eye is upward and out
Causes of fourth nerve palsy
congenital, ischaemic (diabetes, hypertension), trauma
Presentation of sixth nerve palsy
eye is medial
Causes of sixth nerve palsy
ischaemic (diabetes, hypertension), trauma
Which pathologies constrict and which dilate pupils?
Constrict = horners and narcotics; dilate = CN3 lesions and amphetamines
Causes of unilateral ptosis
cranial nerve 3 lesion with dilated pupil; horners with constricted pupil
Causes of bilateral ptosis
myotonic dystrophy, myasthenia gravis, mitochondrial myopathy, diabetes, thyroxine, miller fischer syndrome (GBS) with ataxia and areflexia and complex ophthalmoplegia
Causes of motor only weakness
myasthenia gravis, motor neuron disease, inflammatory myopathy (polymyositis, dermatomyositis, inclusion body myositis), multifocal motor neuropathy (unilateral, LMN, autoimmune = anti-GM1)
Causes of weakness with sensory component
guillian barre, chronic inflammatory demyelinating polyneuropathy, multiple sclerosis, transverse myelitis (bilateral UMN signs), mononeuritis multiplex (asymmetrical - paraproteins / paraneoplastic / vasculitis), metabolic toxicities
Predominately motor peripheral neuropathy
guillian barre syndrome, chronic inflammatory demylinating polyneuropathy, hereditary motor and sensory neuropathy (charoct marie tooth), diabetes, lead poisoning, multifocal motor neuropathy
Predominately sensory peripheral neuropathy
diabetes, paraneoplastic - lung, B6 toxicity, B12 deficiency, sjogrens syndrome, syphilis
What do these phrases test? Yellow lorry, baby hippopotamus, we see three grey geese.
Yellow lorry - tongue. Baby hippopotamus - lips. Grey geese - palate.
What do these sounds test? Pa, Ta, Ka
Pa - mouth. Ta - tongue. Ka - palate.
Why count to 30 in speech exam?
Fatigue in myasthenia gravis.
Speech findings for bulbar disorder and causes.
Lower motor neuron, slow, low volume, tongue and facial, atrophy. Caused by motor neuron disease, cranial nerve 7/9/10/12 issues, myasthenia gravis, muscular dystrophy.
Speech findings for cerebellar disorder and causes
Ataxia with irregular rhythm and pitch. Caused by spinal cerebellar ataxia, multiple sclerosis, alcohol, tumour, paraneoplastic disorder
Speech findings for pseudo bulbar disorder and causes
Upper motor neuron, slow, strangulated, positive jaw jerk, hyperactive gag, emotionally labile. Caused by bilateral lacunar internal capsule strokes, multiple sclerosis, amyotrophic lateral sclerosis
Speech findings for extra-pyramidal disorder and causes
Rapid, low-volume and monotone speech. Caused by parkinson’s disease.
Anatomical area of receptive aphasia
Wernicke in posterior part of first temporal gyrus in dominant lobe
Anatomical area of expressive aphasia
Broca in posterior part of third frontal gyrus
Area and description of conductive aphasia
Isolated inability to repeat phrases with receptive and expressive intact. Located in arcuate fasciculus (temporal lobe).
Area and description of nominal aphasia
Difficulty recalling or recognising nouns of objects. Located in angular gyrus (temporal lobe). Also noted in encephalopathies and space occupying lesion.
What is the role and physiology of the spinothalamic tracts?
Sensation of pain and temperature. Fibres enter, ascend and decussate in the spinal cord (usually 2 levels above entry).
What is the role and physiology of the dorsal columns?
Vibration and proprioception. Fibres ascend and decussate in medulla.
What is the role and physiology of the corticospinal tracts?
Motor. Descending pathway.
Describe the symptoms of anterior cord syndrome
Bilateral loss of motor, pain and temperature sensation below level of injury. Intact vibration and proprioception. Hyperflexion injury or disruption of anterior spinal artery.
Describe the symptoms of central cord syndrome
Sensory and motor deficit. Upper extremities affected more than lower extremities. Hyperextension injury. Classically in older patients who have underlying cervical disease.
Describe the symptoms of brown-sequard syndrome
Ipsilateral loss of motor, vibration and proprioception. Contralateral loss of pain and temperature. Penetrating trauma or lateral compression.
Describe dyskinesia and outline inherited and acquired causes
Involuntary repetitive movements. Inherited causes: huntington’s disease, wilsons disease and spinocerebellar ataxia. Acquired causes: SLE, sydenham’s chorea, thyrotoxicosis and dopamine blockers.
Key features of parkinson’s disease
pill rolling tremor (often unilateral), bradykinesia, lead pipe (elbow) + cogwheel (wrist) rigidity, difficultly initiating voluntary movements, festinating gate, mask like face, monotone speech, micrographia.
Describe parkinson’s plus syndrome
Similar features to parkinson’s except has poor response to levodopa, symmetry and early onset dementia/hallucinations
Key features of multiple system atrophy
autonomic dysfunction, cerebellar ataxia, UMN
Key features of progressive supranuclear palsy
gaze palsy (vertical first), axial rigidity
Key features of corticobasal degeneration
limb apraxia, dystonia, myoclonus
Causes of hemiparesis and presentation, also with ACA vs MCA
Caused by stroke, tumour, abscess, demyelination or post ictal (Todd’s). Presents with fixed flexion of upper limb, increased tone and increased reflexions. ACA >legs, MCA >arms/face.
Causes of pseduo bulbar palsy
stroke-bilateral, MND, MS, CJD
Causes of bulbar palsy
MND, myasthenia gravis, GBS, myotonic dystrophy
Describe symptoms of posterior (dorsal) column syndrome
bilateral loss of proprioception and vibration only, preserved power (corticospinal) and sensation/temp (spinothalamic)
What sensation level corresponds to the nipple and the navel?
T4 = nipple. T10 = navel.
Presentation of frontal lobe stroke
expressive (broca’s) dysphasia, disinhibition, loss of smell, repeating words
Presentation of temporal lobe stroke
receptive (wernicke’s) dysphasia, superior quadrantanopia, not recognise sounds/faces
Presentation of parietal lobe stroke
sensory inattention, inability to follow 3 step commands, inferior quadrantanopia, can’t read letters or perform calculations
Presentation of occipital lobe stroke
homonymous hemianopia, cortical blindness/visual agnosia
Presentation of cerebellar stroke
gait or truncal ataxia (leaning towards lesion), nystagmus, dysmetria, past pointing, intentional tremor
Presentation of medullary stroke
double vision, vertigo, vomiting, nystagmus, leans towards stroke
Presentation of lateral medullary syndrome (wallenbergs)
Occlusion of PICA. Sensory only (4S). 1. Ipsilateral loss of pain/temp in face (sensory nucleus of 5th cranial nerve). 2. Contralateral loss of pain/temp in limbs (spinothalamic pathway). 3. Ipsilateral cerebellar signs (limb ataxia, vertigo, dysarthria (spinocerebellar pathway)). 4. Ipsilateral horners (sympathetic pathway).
Presentation of medial medullary syndrome (think motor)
Occlusion in perforators off vertebral/proximal basilar. Mostly motor (4M). 1. Ipsilateral loss of CN 3,4,6,12 (divisible by 12, tongue deviates towards lesion and complex ophthalmoplegia) (motor nucleus). 2. ipsilateral inter-nuclear ophthalmoplegia (MLF). 3. Contralateral weakness of the arm and leg (motor corticospinal tract). 4. Contralateral loss of vibration and proprioception in the arm and leg (medial lemniscus).
Presentation of PCOM aneurysm
CN 3 palsy with headache
Which nerve damage causes claw hand
Ulnar nerve, inability to extend fingers at interphalangeal joints, causing flexion (4th and 5th fingers). Also weakness of abducting/adducting of fingers, adducting of thumb, wasting of small muscles and loss of sensation in 4th/5th fingers. C8-T1.
Which nerve damage causes ape hand
Median nerve, inability to oppose thumb. Wasting of thenar eminence (abductor pollicus), weakness of 2 and 3 finger flexion (benediction sign), weakness of thumb abduction, sensory loss over palmar aspect of first three fingers and tinel’s and phalen’s positive. C6-T1.
Which nerve damage causes wrist drop
Radial nerve, inability to extend the hand or fully extend forearm. Weakness of wrist extension, first and middle finger extension, forearm supination (if lesion from spinal groove), and elbow extension (if lesion in axilla). Also loss of sensation over snuff box/thumb. C5-8.
Two causes of wrist drop
- radial nerve lesion = also weak finger extension + supernation of forearm (affecting brachioradialis). 2. C7 nerve root damage = also weak wrist flexion and elbow extension
Three causes of small hand wasting
- Anterior horn cells (spinal cord) = generalised wasting of the hand, LMN signs, caused by MND, spinal muscular atrophy and polio, 2. Brachial plexus (nerve root C8-T1) = pancoast tumour (check for horners), cervical rib, radiculopathy and trauma. 3. Peripheral nerve originating from C8 to T1 = eg. ulnar or median nerve palsy (check for hand claw + weakness in nerve distribution), caused by muscular dystrophy (myopathic facies).
Presentation of complete brachial plexus lesion (plexopathy)
LMN lesion sign which affects whole arm, sensory loss throughout arm, ?associated horners
Presentation of nerve root (radiculopathy) eg C5/6 lesion
Loss of shoulder movement and elbow flexion, sensory loss over lateral arm/forearm.
Features and causes of motor neuropathy
Distal wasting and weakness with depressed reflexes. GBS/CIPD, porphyria, lead, drugs (vincristine, nitrofurantoin, isonazid).
Features and causes of sensation neuropathy
Loss of hair, reduced sensation or proprioception (distal > proximal), ataxia due to sensory losses. Small fibre neuropathy = touch, pain, temperature loss, autonomic dysfunction = DM, EtOH. Large fibre neuropathy = vibration and proprioception loss (B12 def > dorsal spino-cerebellar tract).
Causes of combined sensory motor neuropathy
alcohol, diabetes, drugs, GBS/CIDP, paraproteins, vasculitis, uraemia (CRF), HMSN (CMT/SMA), paraneoplastic disease, HIV, mononeuritis multiplex, hypothyroidism, amyloid/sarcoid
Investigations for peripheral neuropathy
HbA1c, B12, folate, TFT, FBP, UEC, QEP/SFLC, CK, ANA/ANCA, HIV, NCS, EMG
What would a cerebellopontine angle tumour compress, cause and be caused by?
Compresses pons CN 5-8. Causes reduced facial sensation (CN 5 palsy), weakness of muscle mastication (CN 5), cannot abduct eye (CN 6 palsy), facial weakness upper and lower face (CN 7 palsy, LMN), hearing loss (CN 8 palsy). Caused by acoustic neuroma, meningioma, basilar artery aneurysm, brain mets.
Differentiate LMN and UMN causes of facial nerve palsy (CN 7)
Forehead sparing (central cause - brainstem stroke with CN 5/6/8 palsies or MND). Affects forehead (LMN, check for vesicles - Ramsay-Hunt, or idiopathic as in Bell’s - 95% of time, also cerebellopontine angle/parotid tumour, MG/GBS)
Causes of bilateral facial palsy
GBS, MG, myotonic dystrophy, MND
Signs of syringomyelia (spinal cord cyst), differentiate anterior horn, lower horn and below lesion.
Typically C8-T1, surgical scar on neck, loss of pain and temperature sensation (spinothalamic tract). Anterior horn = LMN signs (fasciculations, small hand wasting, reduced reflexes) in upper limb. Lateral horn = horners syndrome. Below lesion = UMN signs in lower limb.
Signs of cervical myelopathy
wasting of arm and hand muscles, pyramidal weakness in upper limb, sensory loss throughout C5-C7 distribution, reduced bicep jerk, increased tricep jerk, myelopathy hand sign (outward movement of 4th and 5th fingers), hoffman positive and spastic paraparesis in lower limb.
Describe and list signs of motor neuron disease
Neuronal loss at all levels of motor system including cortex > brainstem > anterior horn cells. Bulbar signs = dysarthria with nasal speech, can be pseudobulbar or bulbar weakness. LMN signs = proximal and distal wasting of all limbs, fasciculations of all limbs. UMN signs = hypertonia and hyper-reflexia throughout and ankle clonus.
Describe disease, presentation and causes of horners syndrome
Damage to sympathetic nerves from spinal cord to face. Has pupil constriction (miosis), ptosis (overcome by upward gaze), ipsilateral anhidrosis of face and no ocular palsy (normal eye movement). Central causes = MS, brainstem lesion (lateral medullary syndrome), syringomyelia. Peripheral causes = pancoast tumour, cervical rib, carotid artery dissection, lymphoma, brachial nerve injury.
Describe the orders of horners syndrome and there respective causes
1st order = brainstem to c spine = trauma, stroke, syringomyelia. 2nd order = nerve root, lung apex = cervical rib, plexus injury, tumour. 3rd order = carotid artery, cavernous sinus orbital = dissection, herpes zoster, base of skull mass
Presentation and diagnosis of guillian barre / CIDP / MFS
Motor/sensory with diminished reflexes. Bilateral weakness (distal legs, proximal arms), reduced peripheral sensation/paraesthesia, reduced/absent reflexes, bulbar weakness (especially miller fisher), respiratory/diaphragm weakness. Diagnose with CSF (high protein, anti-ganglioside Ab) and NCS (demyelination with delayed conduction).
Presentation and diagnosis of myasthenia gravis
Face and neck motor weakness with fatiguability and bulbar. Ptosis (made worse on sustained upward gaze), bilateral facial and neck muscle weakness, bulbar weakness with swallow and nasal voice (not in LEMS), proximal limb weakness (arms > legs) with fatiguability, difficulty breathing. Tests = acetylcholine/musk receptor abs, tensilon (cholinergic test) test to see for improvement. EMG = reduced muscle action potential amplitude and increased fibrillation.
Presentation and diagnosis of multiple sclerosis
Ocular = internuclear ophthalmoplegia, rapid afferent pupillary defect, reduced visual acuity, optic atrophy (pale optic disc). Motor (UMN) = pyramidal weakness, increased tone/spasticity, increased reflexes. Sensory = reduced dorsal column signs (vibration and proprioception) and Lhermitte’s sign. Cerebellar = reduced upper and lower limb coordination, ataxia and slurred speech. Tests = MRI, Visual Evoked Response, LP (oligoclonal band).
Signs of cerebellar syndrome
DANISH. Dysdiadochokinesia, ataxia (upper and lower limbs), nystagmus, intention tremor, slurred speech, hypotonia/hyporeflexia.
Unilateral causes of cerebellar syndrome
Ipsilateral to lesion. Cerebellar stroke, lesion and trauma. MS
Bilateral causes of cerebellar syndrome
Toxin (alcoholic, drugs = phenytoin, lithium), hereditary ataxia (fredreich’s ataxia, spinocerebellar ataxia, ataxia -telangiectasia), paraneoplastic syndrome (anti-hu, yo, ri), endocrine (wilson’s, hypothyroidism), vitamin e def.
Presentation of myotonic dystrophy
LMN, with sensation spared. Myopathic facies (wasting of facial muscles), fontal balding, bilateral ptosis, slow releasing hand grip, thenar thumb reflex, distal limb wasting and weakness, reduced muscle tone (possibly fasciculations), bilateral foot drop with high stepping gait, systemic features (valvular disease (mitral regurgitation), cardiomyopathy (CCF signs), PPM (arrythmia), respiratory distress (home o2)).
Presentation of facioscapulohumeral muscular dystrophy
Bilateral ptosis, wasting of temporal / masseter muscles, myopathic facies with weakness of facial muscles (eyes, mouth, neck), scapula winging with severe proximal upper limb weakness and wasting (lower limb also affected)
Differentials of bilateral spastic weakness
- MS (ocular and cerebellar signs). 2. Motor neuron disease (LMN, bulbar involvement, muscle wasting, nil sensory). 3. Hereditary (Fredrich’s) ataxia (upper and lower limb cerebellar signs, muscle wasting, pas caves, weakness and kyphosis). 4. Hereditary spastic paraplegia (spasticity of the legs only, UMN signs (increased tone, hyper-reflexia, clonus). 5. Cord lesion / transverse myelitis (sensory level affected, scars). 6. B12 Deficiency (proprioception/ vibration, sensory loss, ataxia, UMN (spasticity/hyper reflexes) and rhombergs)
Presentation of charcot marie tooth
LMN, sensation affected. Most common inherited neurological disorder (auto-dominant). Symmetrical distal wasting hand and feet (champagne bottle legs). Reduced distal sensation, clawing of hands and feet, pes cavus, absent reflexes, ataxic high step gait (foot drop), thickened peripheral nerves (onion skinning).
Causes of pes cavus
muscular dystrophy, cerebral palsy, MND, CIDP, spinal cord injury
Presentation of Friedrich’s Ataxia
Cerebellar syndrome with muscle wasting. Most common hereditary ataxia (autosomal recessive mutation in FXN gene). Broad based ataxic gait, upper limb ataxia, slurred speech, bilateral nystagmus with hypermetric saccade, distal muscle wasting, weakness in pyramidal distribution (extensors arms, flexor legs), impaired vibration or proprioception, reduced reflexes (spasticity in later stages), pes cavas, scoliosis, cardiomegaly. Similar signs in spinocerebellar ataxia.
Causes of unilateral weakness
Cortical lesion (UMN - stroke, tumour, MS), nerve root palsy (LMN), isolated nerve compression (radial nerve), multifocal motor neuropathy (MMN)
Causes of distal weakness
peripheral neuropathy (DM/B12/EtOH/vasculitis), hereditary myopathy (myotonic dystrophy/duchenne), hereditary neuropathy (CMT/SMA), motor neuron disease (with UMN), IBM (hands however proximal weakness in lower limb), syringomyelia (usually LMN signs)
Causes of proximal weakness
NMJ (myasthenia gravis - motor only), autoimmune (CIDP/GBS - motor, sensory, areflexic, distal legs, proximal arms), endocrine (thyrotoxicosis, cushings), inflammatory myopathies (PM), drugs (steroids/statins), metabolic myopathies (electrolytes), vasculitis
Give 4 examples of parkinson plus syndrome
Lewy body dementia, PSP, MSA, cortical basal degeneration
Give symptoms of Lewy body dementia
early onset with hallucinations
Management of parkinsons
- Levodopa. 2. Dopamine agonists - effective in early disease to decrease dyskinesia but increases cognition issues. 3. Catechol-o-methyl transferase inhibitors which prevent levodopa breakdown by enzymes. 4. Surgery - thalamotomy / pallidotomy
Difference in lack of coordination caused by dorsal column and cerebellar
Dorsal column (proprioception) - ataxia with eyes closed, as well as decreased vibration and proprioception. Cerebellar - always ataxic, also nystagmus and poor coordination in both upper and lower limbs.
What causes shuffling gait
parkinsons
What causes spastic gait
hereditary spastic paraplegia, subacute combined degeneration, spinal cord lesion
What causes wide based gait
cerebellar and posterior column
What causes high stepping gait
distal weakness
What causes waddling gait
proximal weakness
Components of parkinsons exam
mask like facies with lack of blinking, gait, resting tremor, rigidity, glabellar, ocular ROM, writing, frontal reflexes, postural hypotension
Components of cerebellar exam
gait (s1 toes, l4/5 heels), rhombergs, lower limb sx, upper limb sx, nystagmus, speech (hippopotamus), truncal ataxia, other neuro
Causes of ischaemic stroke
Cardiac embolism 20%, large artery occlusion 20%, subcortical lacunar infarct- hypertension 25%, cryptogenic 30%, vasculitis/ genetic/ sinus thrombosis 5%
Management of ischaemic stroke
Thrombolysis if within 4.5 hours. Thrombectomy if 18 hours. Aspirin (+clopidogrel) 6weeks. Anticoagulation for AF. Statin. BP control. Rehab.
Investigations for stroke
CT / MRI / carotid ultrasound. Ecg / holter/ consider ECHO. Ix connective tissue disorders or antiphospholipid syndrome if younge.
Risk factors for stroke
Age, smoking, hypertension, diabetes, high lipids, AF, previous strokes
Presentation of posterior stroke
Bilateral weakness (basilar), medullary, cerebellar signs, bilateral vision loss
Management of Guillian Barre Syndrome and CIDP
IVIG for GBS, steroids for CIDP. Plasma exchange. Ventilation.
Investigation findings for GBS
Infection- campylobacter, mycoplasma, CMV, EBV, HIV. Raised protein levels in CSF. Slowed motor conduction and reduced sensory action potentials on nerve conduction studies and EMG. Reduced FVC. Anti-ganglione antibodies (anti-GM1, anti-GQ1b in Miller Fisher)
Presentation of Guillian Barre Syndrome
Ascending muscle weakness, absent reflexes, sensory loss (more dorsal column - vibration and proprioception), breathing difficulties, bulbar symptoms (speech/ swallowing difficulties), autonomic neuropathy (postural hypotension and arrhythmias)
Management of Myasthenia Gravis
Pyridostigmine (acetylcholinesterase inhibitor). Steroids. Immunosuppressant if steroids fail (azathioprine, ciclosporin, MMF). IVIG or rituximab. Thymectomy. Treat underlying infection or cease aggrevating drug.
Antibodies for Myasthenia Gravis
Acetylcholine receptor antibodies, 80 to 90% positive. MUSK, 40% of those seronegative to acetylcholine receptor antibodies. Voltage gated calcium channel antibodies - Eaton Lambert secondary to small cell lung cancer (mostly upper limb, no bulbar)
Investigations for Myasthenia Gravis
Antibodies. Electomyogram (reduced action potentials amplitudes). Thymoma screening. Lung volume testing (exclude reduced FVC).
Risk factors for Myasthenia Gravis
Previous thymoma or thymectomy. Autoimmune condition, SLE or RA
Presentation of Myasthenia Gravis
Occular (90%), ptosis, diplopia (muscle fatigue - peek sign). Bulbar - dysarthria, dyaphagia. Neck weakness. Proximal muscle weakness with fatigue in exertion with recovery at rest. Reflexes and sensation present.
Presentation of Multiple Sclerosis
Spastic paresis. Parasethesia. Posterior column loss. Visual disturbance (optic neuritis with cortical vision loss, eye pain, diplopia). Relevant afferent pupillary defect. Intranuclear opthalmaplegia. Cerebellar triad (ataxia, dysarthria, tremor). Urinary urgency and faecal incontinence. Depression, dementia, seizures, vertigo. Aggravating factors like heat, infection and pregnancy. Lhemittes sign - electric shocks in upper limb with neck flexion (c spine lesion).
Complications of Multiple Sclerosis
Immobility, visual loss, incontinence, social disability.
Management of Multiple Sclerosis
- Supportive treatment- baclofen for bladder or muscle spasticity, amitryptyline for urinary urgency, duloxetine for facial spasms, support groups, IV methylprednisolone for acute flares. 2. Immunotherapy. 3. Natalizumab (alpha4 integren antibody, good for RR MS, can cause progressive multifocal leukoencephalopathy). 4. Ocrelizumab (monoclonal for CD20). 5. Fingolimod / siponimod - sphingosine 1 phosphate receptor inhibitor lymphopenia. 6. Teriflunomide- pyrimidine synthesis inhibitor (leflunomide) causes GI symptoms and hair loss
McDonald criteria
- MRI demonstrates more than 1 T2 lesion within the periventricular, infratentorial, spinal cord or juxtacortical regions. 1. New lesions over space and time.
Investigations for multiple sclerosis
McDonald criteria. Oligoclonal antibodies or raised IgG in CSF. Visual provoked responses are delayed.
Risk factors for multiple sc
Smoking, far from equator, family history
