Neuro Flashcards
Leg dermatomes
L2 - mid thigh L3 - over the top of the knee L4 - medial calf L5 - lat calf S1 - edge of dorsum foot
Then do stocking distribution
vibration sensation
Test on most distal bony prominence and assess when stops, work up if cannot feel
polyneuropathies that are predominantly motor
GBS, lead poisoning, Charcot Marie tooth
causes of sensory-motor peripheral neuropathy
Metabolic causes: • Diabetes (most common) • hypothyroidism • vitamin deficiencies such as B1, B6 and B12 • uremia
Toxic causes: • alcohol (most common) • chemotherapy agents • antibiotics • Lead (predom motor)
Immune-mediated /inflammatory conditions: • acute onset- GBS (predom motor) • chronic inflammatory demyelinating polyneuropathy (CIDP) • Lambert-eaton / Myasthenia Gravis • rheumatoid arthritis • Sjogren's • SLE • sarcoidosis • ANCA positive vasculitis
Paraneoplastic causes,
• Solid organ malignancy such as lung cancer
• or paraproteinemia
Genetic
• Charcot marie tooth (predom motor)
Electrophysiology in peripheral neuropathy
Nerve conduction studies can distinguish between axonal and demyelinating causes
and if length-dependent
axonal vs demyelinating causes of peripheral neuropathy
distinguish with nerve conduction studies
Axon loss
• trauma / toxic / ischemic / metabolic / genetic conditions
Demyelination
• compressive neurop
• hereditary neurop
• acquired immune-mediated e.g. GBS and CIDP
Interpretation of Romberg’s test
If ataxic and Romberg positive- implies ataxia is sensory in nature (i.e. from loss of proprioception)
If ataxic and Romberg’s not positive- implies ataxia is due to cerebellar dysfunction
Next steps of investigation for peripheral neuropathy
- Bedside tests for diabetes: CBG, urine dipsticks
- Diabetic retinopathy w fundoscopy
- Basic blood tests including antibodies
- Nerve conduction studies
Features of charcot marie tooth
Generalised wasting, particularly distal - inverted champagne bottle
Weakness - high stepped gait/ foot drop
Reduced sensation
Is charcot marie tooth demylinating?
There are many types, some demylinating and some axonal
Type 1 is associated with demyelination
Inheritance of charcot marie tooth
Can be auto dom, recessive or X-linked
Most common is Type 1 which is auto dom
Causes of third nerve palsy
Congenital vs Acquired
Acquired
- Vascular ischemia (commonly diabetes, hypertension)
- Vasc abnormality like aneurysm (esp in PKD)
- SOL
- Inflammation / infection
- Demylinating - MS
- Post-op
- Cavernous sinus thrombosis
Ophthalmoplegic migraine
third nerve palsy signs
- Ptosis (paralysis of levator palpebrae superioris muscle)
- “Down and out” occular deviation
- Pupil becomes fixed and dilated/mydriasis (paralysis of sphincter pupillae)
- Diplopia
Drug triggers for Myasthenia Gravis
Aminoglycosides - Gent, Neomycin Beta blockers Cipro D-penicillamine (for Wilson's) Fluoroquinolones - cipro , Levo Quinine Magnesium Statin
Lambert Eaton Vs myasthenia gravis
In LES:
• rare to have opthalmeplegia
• rare to have severe repiratory muscle weakness
- but has autonomic dysfunction: dry mouth /metallic taste, constipation, and erectile dysfunction
- Fatigue IMPROVES with exercise in LE
- LEMS voltage gated calcium channel
- MG AChR
Features of myotonic dystrophy
Most common adult onset muscular dystrophy
Auto Dom, shows anticipation
CTG repeat mutation
Frontal balding Cataracts Bilat ptosis Facial weakness Testicular atrophy Arrythmia Reduced IQ
Differential of bilat ptosis
- MG
- Muscular dystrophies (Myotonic, Occulopharyngeal)
- Chronic progressive external opthalmeplegia
- Congenital
- Bilat Horner’s
- Syringomyelia
Arm dermatomes
C5 - lat upper arm
C6 - lat lower
C6 specifically median nerve - Lat (thumb) edge of hand
C7 - middle finger
C8 specifically ulnar nerve - medial edge (little finger)
C8 - medial lower arm
T1 - medial upper arm
Jaw jerk reflex
Tests CN V - trigeminal
When abnormal, with upper motor neuron lesions, there is a hyperactive or repeating reflex
(past test says you don’t feel anything normally)
CN for facial expression
CN 7 - facial
can test strength too, by attempting to pull apart
cough reflex
starts with stimulation of irritant receptors with afferents in the vagus nerve (CN X)
Specific sign of ALS
first dorsal interosseous muscle wasting ( thenar eminence ) compared to the hypothenar
AKA split hand sign
MND with only lower motor neuron signs
Spinal muscular atrophy (SMA) - autosomal recessive
Kennedy disease - X-linked recessive
Motor neuropathy with conduction block - acquired and treatable
What is the difference between fasciculation and fibrillation?
Both can be picked up on EMGs
Fibrillations are action potentials of individual fibres
Fasciculation is the summation of them all.. and are VISIBLE
signs and symps of MND
Rapid and aggressive asymmetrical disease process involving upper and lower motor neurons
May have behavioral / cognitive dysfunction frontotemporal dementia
three key features of MND
Weakness
Fasciluations
Wasting
Management of MND
Full mdt, dietician, SALT, specialist nurse, resp function monitoring
NIV, gastrostomy
Riluzole has small effect in prolonging survival
What treatment for MND extends life longest?
NIV extends 7 m
Riluzole extends 3m
Claw feet and motor sensory neuropathy
Charcot Marie tooth
Syncope differentials
Vasovagal
• Postural hypotension
• Micturition syncope
• Anxiety
Cardiac
• Arrhythmia
• AS
• HOCM
Respiratory
• PE
Neurological • Seizures (?TS etc) • TIA / stroke • Lack of sleep • Autonomic dysfunction (DM / Parkinson’s / MSA) • ICH / SOL • Meningitis etc
Drugs
• Alcohol
• Withdrawal / OD
Endocrine • Hypoglycaemia • Diabetic autonomic neuropathy • Addison’s • Electrolyte disturbance
Eye examination in Parkinson’s
Myerson’s sign / glabellar tap sign - tap between eyebrows and unable to resist blinking - early sign
Nystagmus - multisystem atrophy
Vertical gaze palsy (especially downgaze) - progressive supranuclear palsy
causes of cerebellar dysfunction
- MS or MSA
- Alcohol (and other drugs)
- Vascular - Posterior circulation stroke
- Inherited (ataxic telangiectasia, Friedreich’s ataxia) Inflammatory (Miller Fisher), Infectious (HIV, syphilis, CJD)
- SOL
Syncope twitch Vs seizures
Syncope fall flaccid, random twitching, rapid recovery
Seizures tend to be rigid and more repetitive movement
Incontinence isn’t a great differentiator
Tongue biting particularly side or back are indicative
Red flags of syncope-
unprovoked or during exercise
murmur
family history
Key features of Myasthenia gravis history
Fatigability
Ptosis that gets worse during the day
Intermittent double vision , or changes -and DRIVING
Chewing getting worse by end of meal
Head drop
Brushing/washing hair etc
Co existing autoimmune
Criteria indicating potential myasthenic crisis
- FVC < 20 or progressive decline
- Can’t complete sentences
- Can’t control their own secretions
- Can’t lift head off pillow
….all require ICU assessment early
What can worsen myasthenia gravis?
Drugs gent,
BASIC LM in caution
Beta blockers Aminoglycosides - Gent, Neomycin Statins Iodine Calcium channel blockers Lithium Mg
epilepsy advice for patients
- Don’t take baths,
- If you swim, go with someone else
- Don’t use heavy machinery
- Pregnancy and medications
- Driving - 6 months if normal EEG, or 12m, or 5 years if HGV driver
- Offer support from Epilepsy Society, specialist nurses and Letter for employer
spasticity vs rigidity
both increased tone, but spasticity is velocity-dependent
What are the functions of the facial nerve
“face, ear, taste, tear”
Causes of Bell’s Palsy
Likely related to HSV
More likely in pregnancy, diabetes
Mx of Bell’s Palsy
- Prednisolone within 72 hours of onset improves outcomes
- plus aciclovir if severe
- Artificial tears
Causes of unilateral ptosis
• IIIrd nerve palsy
—>Down and out eye + fixed dilated pupil
• Horner’s syndrome
—>Ptosis + anhidrosis + miosis
• Myaesthenia Gravis
—>Bilateral facial weakness + proximal weakness with fatiguability + weak voice
• Congenital
Examination for myasthenia gravis
- Count as high as you can on one breath (<15 is bad)
- Fatigued upward gaze
- Ab- and adduct arms then do it 20X and see if weaker
- Same with head
Horner’s V third nerve palsy
Both ptosis
• Horners is Miosis (Constricted Pupil) with anhydrosis
• Third nerve is Midriasis and down and out
Causes of third nerve palsy
- Idiopathic
- Vascular -diabetes, ichaemic, anneurysm
- Space occupying lesions
- Autoimmune disorders such as myasthenia gravis
- Cavernous sinus - tumour, thrombosis
If involves PUPIL it’s SURGICAL (i.e. cavernous
Cerebellar syndrome causes
- Paraneoplastic
- Alcoholic cerebellar degeneration
- Sclerosis (multiple)
- Tumour (posterior fossa SOL)
- Rare (Friedrich’s and ataxia telangiectasia)
- Iatrogenic - Phenytoin
- Endo -hypothy
- Stroke (brain stem vascular event)
Classical history of cavernous sinus thrombosis
- Young women, recently started the Pill / pregnant
- persistent headache (can be sudden/gradual/diffuse/localised)
- 40% have seizure within 24h
- Reduced GCS and focal symps are common
CT venography
Headache with autonomic features - tearing, drooping, nasal congestion, rhinorrhoea
Cluster headache
- or swollen eyelid, pain around one eye, nasal congestion or rhinorrhoea
- subcutaneous or nasal triptan
- short burst O2
Examination findings of myotonic dystrophy
• bilat ptosis, frontal balding, long face
• Myotonia (impaired relaxation) ask to grip hand then release
• wasting/weakness/areflexia of distal muscles
• Percussion myotonia: percuss thenar eminence and watch for involuntary thumb
flexion
Multiple Sclerosis diagnosis
- Hx separated by time and space
- Visual evoked potentials
- LP: oligoclonal IgG bands
- MRI: periventricular white matter plaques
Management of Multiple sclerosis
- MDT
- OT/PT
- Walking aids
- Symptom-focused (e.g. laxatives, opthal input, antidepressents, ED treatment etc)
Acute attacks
• IV methylpred (shortens attacks)
DMARDs
• if more than one relapse/year
• Interferon-beta (reduces relapse rate)
peri-oral fasciculation
perioral fasciculations are almost pathognomonic for Kennedy’s disease
X-linked disease, slow progression
(weakness, wasting and fasciculations, like MND but only LMN)
Horner’s causes
Central TRUNK + ARMS + FACE
• brain stem - ms stroke
• Spinal cord- syringomyelia
Pre-ganglionic FACE only
• Neck - Pancoast’s tumour, Aneurysm
Post-ganglionic no sweating
• Herpes Zoster
Holmes–Adie (myotonic) pupil
• Moderately dilated pupil
• Sluggish reflex
• Reduced /absent ankle /knee
…Benign, reassure
Young patient with TIA differentials
- Hypoglycaemia
- Migraines
- Todd’s paresis
- MS if relapsing remitting
- SOL
- Antiphospholipid (anti-cardiolipin Ig)
- Valvular heart disease
- Takayasu arteritis (pulseless)
- Subacute bacterial endocarditis
- Cerebral vasculitis
- Sickle Cell
- DVT ?paradoxical embolism
Signs of raised ICP on examination
- Reduced GCS
- Papilloedema
- Reduced visual fields
- Unilateral ptosis or third and sixth nerve palsies
Epilepsy counseling in pregnancy
- If seizure-free before conception , likely to remain so
- Most have normal pregnancies
- Some anti eps may have a low risk, but inadequate seizure control is likely higher risk - aim for lower appropriate dose
- Valproate is contraindicated in preg ( birth defects and developmental disorders, cardiac+NTD ) so only if really necessary
- Lamotrogine effectiveness may be reduced by oestrogen contraception
- Risks of Status to m+b - more common in preg due to preg + sometimes changing meds , but also reg repeated seizures carries risk (esp tonic-clonic)
• Remember folate replacement
Features of hemiplegic migraines
- Hx of migraines(!)
- Not specific to vascular territory
- May develop over minutes-30mins
- Less common in elderly
- Recurrent
Stroke and Seizures
- 4% of patients with stroke will have a seizure
- More likely in haemorrhagic stroke
- Likely wont develop post-stroke epilepsy
Aphasia in stroke
- 97% will have assx R-sided hemiplegia
- The others will be R-dominant, likely L handed
If L-sided hemiplegia and Aphasia ?conversion syndrome
Crescendo TIA differential
Amyloid Spells
- stereotyped, recurrent, transient neurological episodes of paraesthesias, numbness or weakness
- Old, hypertensive
- Onset over seconds to minutes, then resolves
- Respond to Valproate
Vascular Parkinsonism
- Predominant lower limb symptoms (unlike idiopathic)
- Shuffling or freezing gait
- Bilat mild tremor
Parkinson’s medication counselling
- Nausea / Vomiting
- excessive sleepiness, hallucinations, and impulse control disorders - more likely with MOA then L-Dopa
- COMT inhibitors get conf/hallucinations
- MAOb cause postural hypotension
?Parkinson’s management
- Refer to PD specialist
- Order CT
- Don’t start Levo
- Stop any drugs that might have caused it (but speak to MH if it’s antipsych etc)
- Give leaflets!
Treatment options with Parkinson’s
- Levo dopa
- MOAb inhibitors
- Dopamine agonist
- Can use Direct Brain Stimulation
- Apomorphine (non-selective dopamine agonist, pump)
Brown-Sequard Syndrome
- Ipsilateral hypertonia, hyperreflexia, weakness, loss prop and vibration
- Contralateral loss of pain and temp
Causes of Brown-Sequard Syndrome
- Demyelination
- Trauma
- Spinal cord tumours
- Longitudinal myelitis
Which nerve for wrist drop?
Radial nerve
C5 through T1 nerve roots
Causes of wrist drop
- Compressive nerve entrapment = “Saturday night palsy” is a commonly seen when the radial nerve is acutely compressed at the spiral groove
- Stab wound jsut below clavicle (posterior brachial plexus)
- Humeral fracture (radial groove in lat border)
- Persistent injury from using crutches, or leaning on elbows
- Lead poisoning
- Thiamine deficiency (beriberi)
- Limb-onset amyotrophic lateral sclerosis
- Hereditary neuropathy with pressure palsies (HNPP)
Magement of wrist drop
- Depends on cause… 70% conservatively Mx
- Splint
- Could consider surgery
- Likely 2-4 months to heal
Differentials for asymmetric spastic paraparesis
Myelopathy
- Trauma (disc prolapse- most common)
- Ischaemia (spinal infarct)
- Inflammation (Transverse Myelitis, multiple sclerosis)
- Infection (HIV, Varicella)
- Neoplasia
- Metabolic / nutritional disorders (B12, Copper def)
- Hereditary (hereditary spastic paraparesis)
Asymmetric sensory change with proximal muscle weakness
plus reduced tone/reflexes
Likely inflammatory neuropathy (CSF raised protein normal cell count)
• GBS
• Chronic inflammatory demyelinating polyneuropathy
Common causes of polyneuropathy less likely here (like diabetes, alcohol, hypothy) as they are length-dependent
Indications for CT prior to LP
- Focal neurology
- Reduced GCS
- Papilloedema
Syndromes associated with retinitis pigmentosa
- Usher syndrome - commonest cause of deaf–blindness in the UK (can be auto dom/rec/X-linked, or spontaneous in 30%)
- Alport’s syndrome - hearing loss, glomerulonephritis
What would make a diagnosis of immune-mediated peripheral neuropathy more likely?
More likely to be:
• Non-length dependent (i.e. starting in hands, trunk or face)
• Assx with signif sensory ataxia
• Asymmetrical
• CIDP may have waxing and waning symptoms
• May be Assx w inflammatory arthopathy, rashes, sicca symptoms (RA, SLE, Sjogren’s)
• Usually demyelinating
Differentials for Chorea-type movements (random and non-patterned)
Acutely:
• Hyperglycaemia
• Vascular - usually asymmetric: e.g. subthalamic nucleus causing hemiballismus
Immune mediated:
• SLE
• Sydenham chorea (Group A Strep, but rare)
Genetic
• Huntington’s (most common)
Proximal symmetrical reduced power
Normal reflexes, tone, reflexes, coordination
- Either Neuromuscular junction e.g. Myasthenia Gravis
- or myopathy
- AChR antibodies
- neurophysiological would show reducing action potentials in NMJ
Management of myasthenia gravis
if acutely
• ?Crisis- then ABCDE, get FVC and consider ITU
• IVIG / plasma exchange
Sub-acutely:
• Pyridostigmine (helps symps but not prog)
• CT for ?thymoma which would be resected, and improve symps
• Immunosuppressive Tx like steroids, azathioprine, mycofenalate - may have paradoxical “Steroid dip”, so titrate, sometimes in hosp
Third nerve palsy involving pupil vs not
if pupil involved, more likely to be Surgical cause
- Commincating posterior artery aneurysm
- Cavernous sinus pathology
Management of Freidrech’s ataxia
• Diagnosis via genetic testing but rule out things like B12 or E, and MRI brain/spine
- Regular ECGs and echos due to arrythmia’s / cardiomyopathy
- Supportive care w physio / OT
(Auto recessive)
Occular vs generalised Myasthenia Gravis
If limited to occular, closely monitor for two years, as if iit is going to become generalised , likely to be then
What are the CNS complications of HIV?
• meningitis from tuberculosis or when the CD4 count is much lower: • toxoplasmosis • cryptococcal • meningitis • CMV disease
CD4 <50
• Malig (particularly primary CNS lymphoma)
Management of TIA
- Exclude mimics
- Start 300mg Aspirin
- Refer to stroke within 24h
- If strok >7d ago then referral within 7d
- If bleeding disorder/anticoag then CT
- Don’t use ABCD2 to inform referral time!
- Don’t drive until seen specialist
- Inform about symps to look out for
Scoring system for TIA
ABCD2
DON’T USE TO INFORM URGENCY OF REFERRAL as per NICE
• Age ≥ 60 years • BP ≥ 140/90 mmHg • Clinical features ------> Unilateral weakness+2 ------> Speech disturbance without weakness+1 • Duration ------> <10m 0 ------> 10-59m +1 ------> ≥ 60m +2 • History of diabetes
0-3 points: Low Risk
• 90-Day Stroke Risk: 3.1%
4-5 points: Moderate Risk
• 90-Day: 9.8%
6-7 points: High Risk
• 90-Day: 17.8%
ABCD2 score interpretation
DON’T USE TO INFORM URGENCY OF REFERRAL as per NICE
0-3 points: Low Risk
• 90-Day Stroke Risk: 3.1%
4-5 points: Moderate Risk
• 90-Day: 9.8%
6-7 points: High Risk
• 90-Day: 17.8%
Anticoagulation after stroke / TIA
If AF: Aspirin for 2 weeks then Warfarin
If metalic valve replacement: Aspirin for ONE week then Warfarin
Classic Hx of tension headaches
- usually bilateral
- pressing/tightening
- lasting min-dats
- Not assx with N/V or aggrevated by daily living
- May have pericranial tenderness
Simple analgesia
Identify assx stress, mood, chronic pain and sleep disorders
Classic Hx of cluster headaches
- unilateral
- associated tearing, congestion, fullness to ear, eyelid oedema
- can be pulsatile/boring/burning/pressure
- lasts 15-180 mins
- restless/agitated
- can be circadian / triggered by things like alcohol,smell, physical exertion
Cluster headache management
- subcutaneous or nasal triptan
- Do not offer paracetamol, NSAIDs, opioids, ergots or oral triptans for the acute treatment of cluster headache
- Offer short burst oxygen therapy
- Avoid triggers and avoid med overuse
Management of essential tremor
Conservative - do nothing
• Alcohol?
Medical
• Propranolol - caution in asthma
• Primidone (antiepileptic) but can cause drowsiness
Surg in severe:
• thalamotomy
• thalamic deep brain stimulation
Drug-induced neuropathy
- Alcohol
- Amiodarone
- Statins
- Chemo agents (60% of patients on chemo will get neuropathy)
- Isoniazid, Ethambutol, Metronidazole
- Immunosuppressant drugs
- NRTIs
- L-Dopa
Mx after Subarachnoid haemorrhage
- Address hypertension, smoking and excessive alcohol
- Calcium antagonists Nimodipine reduce vasospasm
- neurosurgical clipping and endovascular coiling
Cubital tunnel syndrome prognosis
(Ulnar distribution)
Up to 50% of people get better with conservative, non-surgical treatment
The recurrence rate following surgical decompression is 12%
Sign for ulnar nerve damage
Wartenberg’s sign
• involuntary abduction of the fifth (little) finger
• caused by unopposed action of the extensor digiti minimi
Froment’s sign
• Pinch grip between thumb and index
• Power of adductor pollicus of the thumb, which is innervated by the ulnar nerve
Foot drop nerve
Common peroneal nerve
- Weakness on the everting foot
- Inability to extend the toes
- Paraesthesia over the dorsum of the foot
Association of carpal tunnel syndrome
Usually idiopathic (median nerve)
Can be assx with • Overuse • Trauma • Pregnancy • Diabetes • Hypothyroidism • CKD
Carpal tunnel prognosis
1/3 resolve without treatment in 6 months
Another study found untreated at 2 years:
• 50% resolved
• 25% stable
• 25% worsened
0-12% recurrence after carpal tunnel decompression
Lambert-eaton syndrome / cancer
- autoimmune attack against the P/Q subtype of voltage-gated calcium channels
- Also found on SCLC - so ?body makes them to attack cancer
- Cancer (typically SCLC) is found within four years in virtually all cases
Lamber-Eaton syndrome presentation
- Proximal myopathy over months-years
- waddling gait and difficulty with raising the arms.
- Sometimes ptosis, chewing/swallowing difficulties
- Autonomic symptoms - dry mouth, impotence and postural hypotension may be seen
- Strength may improve initially on exercise but then lessens as exercise is sustained
Causes of proximal myopathy
Endocrine
• Thyroid
• Cushing’s
Drug
• alcohol
• statins
• steroids
Inflammatory
• dermatomyositis//polymyositis (symmetrical, raised CK)
• inclusion body myositis (asymmetrical)
Cancer
• Lambert eaton
• Paraneoplastic - anti-Hu
Neurological
• GBS/CIDP
• myasthenia gravis
Causes without true weakness
• polymyalgia rheumatica
• fibromyalgia
Presentation of inclusion body myositis
- auto recessive or sporadic inflammatory myopathy
- Mostly >50yr
- Proximal myopathy (often asymmetriical)
- reduced reflexes
- dysphagia in 50%
- Fatigue
- resp muscles usually spared
Multiple sclerosis prognosis
• around 5 to 10 years lower than average
parkinson’s examination
Bradykinesia
• tap fingers as large and as fast as you can
• toe tapping
Rigidity
• tone in arms - particular in wrist - feeling resistance
• do it while tapping
• same with leg
• cogwheel is only with tremor superimposed
Tremor
• rest tremor
• postural tremor (outstretched)
• Kinestic tremor (just back and forth finger to nose) don’t go too fast
Gait and balance
• standing without arms
• walking
• balance
Other • functional assessments (that’s the treatment criteria so v important) • Vertical eye movements (PSP) • Cerebellar and L/S BP (MSA) • Cognitive (lewy-body)
