Neurology Flashcards
Where is Broca’s area? What is its function?
- Left frontal lobe, Brodmann‘s area 44 and 45 - Language production
Where is Wernicke’s area? What is its function?
- Left (usually) temporal lobe, Brodmann’s area 22- Perception of language
What are the layers of brain covering?
Skin - Bone - Dura mater - Arachnoid mater - (Subarachnoid space) - Pia mater
Lateral corticospinal tract
Supplies limbs - Fine motor movement - Decussates at medulla
Ventral corticospinal tracts
Supplies trunk (proximal muscles) - Decussates at level of effector muscle - Also motor movement
Corticobulbar tract
Head and neck via cranial nerves
What structures are in the cavernous sinus?
(OTOMCAT) - Oculomotor nerve - Trochlear nerve - Ophthalmic division of trigeminal nerve - Maxillary division of trigeminal nerve - Carotid artery - Abducens nerve
DCML tract
- Ascending (sensory) - Dorsal root -> medulla, then decussates - Fine touch, vibration and proprioception
Spinothalamic tract
- Ascending (sensory) - Decussates at spine 1-2 levels above dorsal entry - Pain, temperature, crude touch - Anterior - trunk - Posterior - limbs
Brown sequard syndrome
- Ipsilateral DCML loss - decussate at medulla - Ipsilateral corticospinal loss - decussate at medulla - Contralateral spinothalamic loss - decussate at spinal cord (1-2 levels above)
Blood supply to the pituitary gland
Anterior - Superior hypophyseal artery - Posterior - Inferior hypophyseal artery The hypothalamophyseal portal system is a branch of The internal carotid artery
Drug for bacterial meningitis in hospital
- Ceftriaxone (3rd gen cephalosporin) - Cefuroxime if prgenant or under 3 months old - Amoxicillin if listeria suspected - Steroids simultaneously (dexamethasone) within 12 hrs
Pathophysiology of Wernicke’s encephalopathy
Combined B1 deficiency (caused by alcohol) and alcohol withdrawal symptoms
Complication on Wernicke’s encephalopathy
Wernicke Korsakoff syndrome: - Confabulation memory loss - make up stories to fill gaps in memory - Ataxia - Nystagmus
Treatment for Wernicke’s encephalopathy
- Parenteral (IV) pabrinex for 5 days acutely - Oral thiamine prophylactically
Cause of transient ischaemic attack and ischaemic stroke
Carotid thrombo-emboli - Thrombosis - Emboli, eg: from atrial fibrillation
Risk factors of stroke
Hypertension - Atrial fibrillation - Ventricular septal defect - Smoking - T2DM - Obesity/hypercholestrolemia - Cannabis and cocaine
Where do transient ischaemic attacks happen?
90% - internal carotid artery (anterior circulation) 10% - vertebral artery (posterior circulation)
Symptoms of ACA stroke
Contralateral hemiparesis and sensory loss - Lower limbs > upper limbs
Symptoms of MCA stroke
Contralateral hemiparesis and sensory loss with upper limbs > Lower limbs - Homonymous hemianopia - Aphasia affecting dominant hemisphere - Hemineglect syndrome affecting non-dominant hemisphere
Symptoms of PCA stroke
Contralateral Homonymous hemianopia with macular sparing - Visual agnosia
Symptoms of vertebral artery strokes
- Cerebellar syndrome; DANISH with the Romberg test (sensory + motorataxia) - Brainstem infarct - CN lesions 3-12
Amaurosis fugax in transient ischaemic attack
- Decreased blood flow to retina through opthalmic, retinal, ciliary artery - Bad sign; often signals stroke is impending
How to differentiate between stroke and transient ischaemic attack (“mini stroke”)
- Stroke: symptoms last 24+ hours, infarct - TIA: symptoms resolve within 5-15 mins usually, always <24 hours, no infarct
Treatment of transient ischaemic attack
- Acutely = aspirin 300mg Prophylaxis long term - Lifestyle changes - Clopidogrel 75mg - Atorvastatin 20-80mg
What percentage of strokes are ischaemic vs haemorrhagic?
Ischaemic - 85% Haemorrhagic - 15%
What are the symptoms of stroke generally called?
Focal neurology
Types of stroke
- Transient ischaemic attack (“mini stroke”) - Ischaemic stroke - Haemorrhagic stroke
Aetiology of haemorrhagic stroke
Ruptured blood vessel - Trauma, Hypertension - Berry aneurysm rupture - Can be haematomas
If a patient is on anticoagulants, what type of stroke would you suspect?
Haemorrhagic until proven otherwise
Symptoms of haemorrhagic stroke
High ICP - always contraindicated in lumbar puncture - Therefore midline shift, risk of tentorial haemorrhage/coning
What’s a lacunar stroke?
Very common type of ischaemic Stroke - Occurs in lenticulostriate arteries (supply deep brain structures) - Ischaemia to basal ganglia, internal capsule, thalamus, pons
Diagnosis of ischaemic and haemorrhagic stroke
non-contrast CT head (identifies haemorrhagic Stroke) - Gold standard: MRI brin with diffusion weightted imaging - carotid Doppler ultrasound - LFTs, FBC and HbA1c to rule out differential diagnoses - ECG
Pronator drift
Specific sign in strokes - Ask patient to lift arms to ceiling - Pronators take over, arm on affected side will pronate
Treatment of ischaemic stroke
If patient presents within 4.5 hours: Alteplase IV (thrombolytic) Prophylaxis: Aspirin 300mg for 2 weeks, lifelong clopidogrel 75mg, atorvastatin, ramipril NICE recommend carotid intervention within 1 week if internal carotid thrombus
Treatment for haemorrhagic stroke
Neurosurgery referral - IV mannitol for High ICP - Atorvastatin, ramipril
Pathophysiology of subarachnoid haemorrhage
Berry aneurysm coin rupture - Or Trauma - Most common at Anterior communicating/ACA junction
Risk factors for subarachnoid haemorrhage
Connective tissue disorders - Hypertension - PKD - Trauma - Inreasing age + family history
Presentation of subarachnoid haemorrhage
Occipital thunderclap headache - Meningism - Kernig and Brudzinski signs - Low GCS - Nerve palsies (CN3 fixed dilated pupil,#REF! non Specific sign of increased ICP)
What are the Kernig and Brudzinski signs?
- Kernig - can’t extend leg when knee is flexed - Brudzinski - when neck is elevated, knees unintentionally flex
What may preceed a thunderclap headache?
Sentinel headache - Preceds berry aneurysm rupture for weeks - In around 50% cases - Throbbing occipital pain
Glasgow coma scale (GCS)
- Out of 15 - Eyes (4), verbal (5), motor (6) 15: Normal 8: Comatose 3: Unresponsive
Differential diagnoses of subarachnoid haemorrhage
Meningitis (signs of infection, no thunderclap headache) - Migraine (no thunderclap headache Or Meningism)
Diagnosis of subarachnoid haemorrhage
CT head, star shape
What would you do if CT for subarachnoid haemorrhage is positive?
CT angiogram to see the extent of the rupture
What would you do if CT for subarachnoid haemorrhage is negative?
- Lumbar puncture - Wait around 12 hours (as that’s when results are most sensitive) - Will see xanthochromia - yellowish CSF due to RBC haemolysis
Treatment of subarachnoid haemorrhage
First line: Neurosurgery + endovascular coiling - Also give nimodipine (CCB, decreases vasospasm and blood pressure)
Pathophysiology of subdural haemorrhage
rupture of bridging vein due to shearing - Deceleration injuries and in abused children (shaken baby syndrome)
Risk factors of subdural haemorrhage
Trauma - Child abuse - Low pressure bleeding - Gradual rise in ICP - Cortical atrophy (eg: dementia)
Presentation of subdural haemorrhage
- Gradual onset with latent period (bleeding is small, accumulation + autolysis of blood) - Signs of high ICP - Fluctuating GCS - Focal neurology later (CN3 palsy)
Signs of high ICP
Cushing triad: bradycardia, High pulse pressure, irregular breathing - Papillodema - Reduced GCS
Complications of subdural haemorrhage
Brainstem herniation - Respiratory arrest
Diagnosis of subdural haemorrhage
Non-contrast CT head -> banana/cresent shaped haematoma, not confined to suture lines, midline shift
How to deduce nature of subdural haemorrhage from NCCT
If acute = hyperdense (bright) - If subacute = isodense - If chronic = hypodense (darker than brain)
Treatment of subdural haemorrhage
Burr hole + craniotomy - IV mannitol to decrease ICP - Address cause If Child abuse suspected
Pathophysiology of extradural haemorrhage
Trauma to middle meningeal artery due to damage to lateral pterygoid Bone - Can feel Fine for hours to weeks until rapid deterioration - cause old blood clots become haemolysed, taking up water, increases volume in skull and increases ICP as a result
Risk factors of extradural haemorrhage
Head trauma - Typically young adults 20-30 (as the dura adheres more firmly the more you age)
Presentation of extradural haemorrhage
High ICP signs - May have extensive traumatic injuries
Complication of extradural haemorrhage
Death from respiratory arrest - Tonsillar herniation and coning of brain = compressed respiration centres - Due to untreated high ICP
Diagnosis of extradural haemorrhage
Non-contrast CT head -> lens shaped hyperdense bleed, confined to suture lines, midline shift due to brain compression
Treatment of extradural haemorrhage
Urgent surgery - IV mannitol to reduce ICP
Symptoms of Wernicke’s encephalopathy
Classic triad: - Ataxia - Confusion - Opthalmoplegia
Diagnosis of Wernicke’s encephalopathy
Clinically recognised + supported with macrocytic anaemia and deranged LFTs
Pathophysiology of Duchenne muscular dystrophy
X linked recessive mutated dystrophin gene - Affects boys exclusively - muscle replaced with adipose
Symptoms of Duchenne muscular dystrophy
- Gower’s sign - Difficulty getting up from lying down - Skeletal deformities (scoliosis, hyperlordosis)
Diagnosis of Duchenne muscular dystrophy
Prenatal tests - DNA genetic tests
Treatment of Duchenne muscular dystrophy
Supportive - Corticosteroids (eg: prednisone) delay progress of muscle weakening
Pathophysiology of Charcot-Marie-Tooth syndrome
- Inherited sensory and motor PNS polyneuropathy - Autosomal dominant mutation on chromosome 17 - PUP22 gene - Childhood - adulthood onset
Symptoms of Charcot-Marie-Tooth syndrome
Foot drop - Stork legs (v thin calves) - Hammer toes (always curled) - Pes planus (flat feet) Or Pes cavus (arched feet) - Reduced deep tendon reflex
Diagnosis of Charcot-Marie-Tooth syndrome
Nerve conduction study - Nerve biopsy - genetic testing
Treatment of Charcot-Marie-Tooth syndrome
Supportive - Orthotics - Physio
What is tetanus caused by?
- Clostridium tetani (gram +ve bacillus) - Inoculation by stepping in dirty soil
Pathophysiology of tetanus
Tetanospasmin toxin produced - Retrograde travels up axons - Causes involuntary muscle spasms
Treatment of tetanus
VACCINE …if a patient has a wound that is susceptible to tetanus and has not been adequately vaccinated, boosters may need to be given
What is varicella zoster virus?
- 90% under 16s have this as chicken pox - Reactivation -> shingles
Pathophysiology of shingles
Peripheral nerves attacked via dorsal root (sensory)
Symptoms of herpes zoster
Painful rash confined to a dermatome
Treatment of herpes zoster
Oral acliclovir (antiviral)
Pathophysiology of Creutzeldt-Jakob disease
Idiopathic misfolded proteins deposited in cerebrum and especially cerebellum - Severe Cerebellar dysfunction
Treatment of Creudzfeldt-Jakob disease
Rare. no treatment - Rapidly progressive and always fatal. Death usually within one year of onset of illness
Diagnosis of Creutzfeldt-Jakob syndrome
Brain biopsy or autopsy
Primary headaches
Migraines - Cluster - Tension - Drug overdose - Trigeminal neuralgia
Secondary headaches
Due to underlying condition: - GCA - Infection - SAH - Trauma - Cerebrovadcular diseae - Eye, ear, sinus pathology
What are migraines?
Episodes of recurrent throbbing headache, sometimes with aura beforehand - Often with change in vision - Most common cause of recurrent headache - May be associated with nausea and vomiting
Who do migraines affect?
Most common in women under 40 - often during PMS
Triggers of migraines 🍫
Chocolate Hangovers Orgasms Cheese Oral contraceptives Lie ins Alcohol Tumult (noise) Exercise
Women with oral contraceptive pill with migraines
STOP, offer alternatives because it can: - Be a trigger - Increase stroke risk - Decrease triptan efficacy
Stages of migraine
Prodrome (days before) - Mood change Aura (part of attack, minutes before headache) - Visual phenomena; zig zag lines Throbbing headache lasting 4-72 hours
Clinical diagnosis of migraines
2 ≤ of: - Unilateral pain - Throbbing - Motion sickness - Mod-severely intense AND 1 ≤ of: - Nausea and vomiting - Photophobia/phonophobia with normal neuro exam
Treatment of migraines
Acute: - Oral triptan (sumatriptan) - or aspirin 900mg Prophylaxis: - Propanolol (topirimate if asthmatic) - Or TCA - Avoid triggers - Consider antiemetics - eg: metoclopramide for n+v - Don’t use opiates - Risk of dependence or worsening nausea
What are cluster headaches
- Unilateral periorbital pain with autonomic features - 15-180 minutes - Most disabling primary headache - Many headaches clustered in small amounts of time
Risk factors for cluster headaches
Male - Smoking - Genetics (Autosomal dominant link)
Symptoms of cluster headaches
Crescendo Unilateral periorbital excruciating pain, May affect temples too - autonomic features and face flushing
Autonomic features as symptoms
Conjunctival injection and lacrimation (watery bloodshot eye) - Ptosis (droopy eyelid) - Miosis (constriction of Unilateral pupil) - Rhinorrhoea
Diagnosis of cluster headaches
- Clinically - 5 ≤ similar attacks confirms
Treatment of cluster headaches
Acute: Triptans (sumatriptan) Prophylaxis: Verapamil (CCB), TCA second line
What is a tension headache?
Bilateral generalised headache, radiates to neck - Most common primary headache - Triggered by STRESS
Symptoms of tension headaches
Tight rubber band feeling around hear - pain Also felt in trapezius - Mild-moderate severity - no motion sickness, photophobia Or aura
Diagnosis of tension headaches
Clinically from history
Treatment of tension headaches
Simple analgesia - aspirin Or paracetamol - Avoid opiates due to dependence
What is trigeminal neuralgia?
- Unilateral pain in 1 ≤ trigeminal branches - No pain between attacks
Risk factors for trigeminal neuralgia
- MS (20x more likely!!!) - Increasing age (50-60) - Female
Triggers for trigeminal neuralgia
Eating - Shaving - Talking - Brushing teeth - Putting on makeup - Wind on face
Symptoms of trigeminal neuralgia
- Electrical shock pain - Seconds - 2 minutes - In V1/2/3
Diagnosis of trigeminal neuralgia
Clinical, 3 ≤ attacks with symptoms
Treatment of trigeminal neuralgia
Carbamazepine (anticonvulsant) Surgery last line - Percutaneous procedures - Sterotactic radiosurgery - Microvascular decompression
Causes of seizures
Vascular Infecion Trauma Autoimmune, eg: SLE Metabolic eg: hypocalcaemia Idiopathic -> epilepsy Neoplasms Dementia and Drugs (cocaine) Eclampsia and everything else
Pathophysiology of seizures
Balance between GABA and glutamate shifts to glutamate - More excitatory - increased GABA inhibition and glutamate stimulation
Risk factors of epilepsy
- Familial inherited - Dementia (10x more likely)
What is epilepsy?
- Idiopathic cause of seizures - 2 ≤ episodes more than 24hr apart
Unique features of epileptic seizures
Eyes open - Synchronous movements - Can occur in sleep
Stages of epileptic seizures
Prodrome - Mood change, days before Aura - Minutes before - Deja vi + automatisms (lip smacking, rapid blinking) - Not always present, mostly seen in temporal lobe epilepsy Ictal event - seizure Post ictal period
Features of post ictal period
- Headache - Confusion + low GCS - Todd’s paralysis - temporary paralysis and muscle weakness if motor cortex affected - Dysphasia - Amnesia - Sore tongue
What are generalised seizures?
Bilateral - always loss of consciousness - Two types: tonic clonic and absence
Tonic clonic generalised seizures (grand mal)
- No aura - Tonic phase -> rigidity, fall to floor - Clonic phase -> jerking of limbs - Upgazing open eyes, incontinence, tongue bitten
What parts of the brain are affected in generalised seizures
All cortex + deep brain - Bilaterally affected
Absence generalised seizures (petit mal)
- Childhood - Moments of staring blankly into space (seconds-minutes) then carrying on where they left off - 3Hz spike on EEG
Tonic vs myoclonic vs atonic generalised seizures
tonic - just rigid - Myoclonic - just jerking limbs - Atonic - sudden floppy limbs + muscles
What are focal seizures?
features confined to a region, eg: temporal - May progress to secondary generalised
Simple focal seizures
no loss of consciousness - patient awake and aware - just uncontrollable muscle jerking - no basal ganglia + thalamus involvement
Complex focal seizures
loss of consciousness - patient unaware - Post ictal period positive - basal ganglia and thalamus involved
Symptoms of temporal focal seizures
aura - Dysphasia - Post ictal period
Symptoms of frontal focal seizures
- Jacksonian march (abnormal movement or sensation limited to one part of the body) - Todd’s palsy (temporary paralysis follows seizures)
Symptoms of parietal focal seizures
Parasthesia
Symptoms of occipital focal seizures
Change in vision
Diagnosis of epilepsy
- CT head + MRI (examine hippocampus, check bleeds, tumours) - EEG - 3 Hz wave in absence - Bloods - rule out metabolic cause/infection
Treatment for epilepsy
- Sodium valproate to all - Except females of childbearing age (15-45) as it’s teratogenic - give Lamotrigine instead
Complication of epilepsy
Status epilepticus - neuro emergency - Seizures without a break back to back OR - Seizures lasting over 5 minutes (long time)
Treatment for status epilepticus
Benzodiazepines - Lorazepam 4mg IV - Again if it doesn’t work, then phenytoin
Risk factors for Parkinson’s disease
family history - Males - Increasing age - Smoking seems to be protective?
Pathophysiology of parkinson’s disease
loss of dopaminergic neurones from substantia nigra pars compacta - Therefore harder to initiate movement
Normal physiology for initiation of movement
Nigrostriatal pathway signals striatum to stop firing to substantia nigra pars compacta - Stops movement inhibition
Cardinal symptoms of Parkinson’s disease
Bradykinesia - Resting tremor - Rigidity - Postural instability
Diagnosis of Parkinson’s disease
- Clinical - Bradykinesia and 1 ≤ other cardinal symptoms
Pharmacological treatment of Parkinson’s disease
- DA agonists (first line in younger patients)- Levodopa + dopa decarboxylase inhibitor (co-beneldopa or co-careldopa) - MOA-B inhibitor can also be used
Issues with Levodopa
- Initially works very well but soon body becomes resistant to it so effects wear off - So don’t give it too early (v.mild symptoms)
Differential diagnosis of Parkinson’s disease
Lewy body dementia - Parkinson symptoms then dementia = Parkinson dementia - Parkinson symptoms after dementia = Lewy body dementia w/ parkinsonism
Pathophysiology of Alzheimer’s disease
Beta amyloid plaques are a breakdown product of amyloid precursor protein - Beta amyloid plaques + tau neurofibrillary tangles in cerebral cortex - increased Cortical scarring + brain atrophy, Decreased Ach neurotransmitter
Risk factors for Alzheimer’s disease
Down’s syndrome (inevitable; APP gene mutation) - ApoE4 allele in familial Alzheimer’s, late onset (1/4 cases)
Symptoms of Alzheimer’s disease
- Agnosia - don’t recognise things - Apraxia - can’t do basic motor skills - Aphasia - can’t talk as well as normal
Alzheimers vs vascular dementia
Alzheimer’s - steady decline Vascular - stepwise decline
Aetiology of vascular dementia
Cerebrovascular damage, eg: stroke, TIA
Symptoms of vascular dementia
UMN signs - General decrease in cognition
Pathophysiology of lewy body demenia
Lewy bodies (synuclein + ubiquitin aggregates) accumulate in cortex
Symptoms of lewy body dementia
Cognitive decline - Parkinsonism
Risk factors for frontotemporal dementia
- Family history; autosomal dominant change in tau protein (chromosome 17) - Family history of MND (TDP-43)
Symptoms of frontotemporal dementia
Shows frontotemporal atrophy: - Speech and language mostly = temporal moreso affected - Thinking + memory affected = frontal moreso
Pathophysiology of frontotemporal dementia
Proteins clump in frontal and temporal lobe
Risk factors for Lewy body dementia
- Age - Parkinson’s - REM sleep behaviour disorder
Incidence of each type of dementia
- Alzheimer’s - 60% - Vascular - 20% - Lewy body - 10% - Frontotemporal - 5%
Diagnosis of dementia
Mini mental state exam (/30) >25 = normal 18-25 = impaired <17 = severely impaired Brain MRI shows cortical atrophy
Conservative treatment for dementia
Conservative; social stimulation, exercise
Treatment for vascular dementia
Antihypertensives eg: ramipril
Treatment of Alzheimer’s
Achase-1 (donepezil/rivastigmin)
Pathophysiology of Huntington’s disease
- Autosomal dominant with full penetrance (all genotypes with express phenotypes) - Lack of GABA and excessive nigrostriatal pathway - CAG appears on chromosome 4, affecting HTT gene
Trinucleotide expansion repeats in Huntington’s
< 35 = no Huntington’s 35-55 = Huntington’s 60+ = severe Huntington’s The more trinucleotide repears, the earlier and more severely symptoms present; anticipation
Symptoms of Huntington’s
Chorea (excessive limb jerking) - dementia - Psychiatric issues - Depression
Diagnosis of Huntington’s disease
- Clinical - Family history of earlier + more severe Huntington’s - Genetic test if necessary
Treatment of Huntington’s
extensive counselling - DA antagonist for Chorea + tetrabenazine
What is Guillain-Barre syndrome?
- Post infection (gastroenteritis/URTI) result in demyelenating response vs PNS myelating oligodendrocytes - Equivalent of MS in the PNS
Risk factors for Guillain-Barre syndrome
Males 15-30, 50-70
Prognosis of Guillain-Barre syndrome
85% recovery
Aetiology of Guillain-Barre syndrome
- C.Jejuni (mc) - Viruses; CMV, EBV, HZV
Pathophysiology of Guillain-Barre syndrome
Molecular mimickry - Organism antigens very similar to those on Schwann cells - Results in antibody production vs Schwann cells -> Demyelination and acute polyneuropathy
Symptoms of Guillain-Barre syndrome
Post infection presentation of: - Ascending symmetrical muscle weakness (+paralysis) - Loss of deep tendon reflexes - Autonomic involvement in about 50% - Resp failure in 35% -> so always monitor breathing
Diagnosis of Guillain-Barre syndrome
- Nerve condution studies (low conduction/block) - Lumbar puncture at L3/4 -> raised protein + normal WCC ( = inflammation, no infection)
Treatment for Guillain-Barre syndrome
- IV Ig for 5 days + plasma exchange - Allergic reaction in IgA deficient patients (CI) - If FVC <0.8, consider intubation + ITU
What is myasthenia gravis?
- Type 2 hypersensitivity - Autoimmune response vs nmj post synaptic receptors - Nicotinic Ach-R and MUSK
Myasthenia gravis in females vs males
Females - 40 year olds - Related to autoimmune disease Males - 60 years old - Related to thymoma (thymus tumours)
Pathophysiology of myasthenia gravis when anti Ach-R
- 85% - Bind to post synaptic receptor + inhibit, competitively - More binding with exertion -> worse symptoms later on - Activate complement causing nmj destruction
Pathophysiology of myasthenia gravis when anti MUSK
- 15% - MUSK helps synthesis Ach-R - Therefore, decreased Ach-R expression on post synaptic membrane
Symptoms of myasthenia gravis
- Muscle weakness - Weak eye muscles - diplopia and ptosis - Jaw fatiguability - Speech fatiguability - Swallowing difficulty (bulbar weakness) - Myasthenic snarl - fig. 1 fig.1
Nature of muscle pain in myasthenia gravis
Worse later on and with exertion - Starts at head+neck and goes to Lower body - Better with rest
Differential diagnosis of myasthenia gravis
Lambert eaton syndrome - Autoimmunity vs presynaptic Ca2+ channels - Symptoms improve with exertion - Associated with SCLC (not thymoma) - Symptoms start at extremities then move to head + neck - Treated with steroids (prednisolone) and immunosuppression (IVIg)
Diagnosis of myasthenia gravis
- Serology -> Anti Ach-R and Anti MUSK high - Tensilon/edrotropium test (increased muscle posert when edrotropium given) - CT thymus - Bedside: icepack test and upward gaze fatiguability
Treatment of myasthenia gravis
- First line: Achase inhibitors; neostigmine/pyridostigmine - Second line: Immunosuppression (steroids)
Complication of myasthenia gravis
Myasthenic crisis - Acute symptoms worsening with severe respiratory weakness - Treated with plasma exchange and IVIg - + BiPAP for resp failure
Where do CN3-12 originate?
Brainstem - Therefore caused by Brainstem pathology eg: Trauma, MS, tumours
What does a CN 3+4+6 lesion cause?
Non-functioning eye
CN3 lesion
Ptosis (eyelid drooping) - Down and out eye - fixed dilated pupil due to EW nuclei dysfunction
CN4 lesion
diplopia looking Down - RARE: always due to Trauma
CN6 lesion
Adducted eye, sign of increased intracranial pressure
CN5 lesion
Jaw deviates towards affected side - loss of corneal reflex - Trigeminal neuralgia
CN7 lesion
- Facial drop with no forehead sparing - Bell’s palsy, parotid inflammation
CN8 lesion
- Hearing loss - Loss of balance - Skull change (eg: Paget’s), compression, middle ear disease
CN9+10 lesion
- Impaired gag reflex (+ swallowing, resp, vocal issues) - Jugular foramen lesion
CN11 lesion
Can’t shrug shoulders or turn head vs resistance
CN12 lesion
Tongue deviation towards side of lesion
How do spinal cord lesion signs present?
Ipsilateral sensory signs - Contralateral motor signs
Spinal cord reflexes
L3/4 = knee jerk - L5 = big toe jerk - S1 = ankle jerk
Types of paralysis
Hemiplegia = one side of the body, brain lesion Paraplegia = both legs, cord lesion
Compression of what parts of which vertebrae causes myelopathy?
C1 -> L1/2 (the spinal cord)
Compression of what parts of which vertebrae causes cauda equina syndrome?
L3 -> conus medullaris and cauda equina
Causes of myelopathy
- Verterbral body neoplasms, mc: mets from lung, breast, RCC, melanoma - Spinal pathology (eg: disc prolapse/herniation)
Symptoms of myelopathy
- Progressive leg weakness with UMN signs - Sensory loss below lesion (as ascending roots send info up) - Sphincter involvement uncommon (late = v bad sign)
Diagnosis of myelopathy
MRI cord ASAP (risk of permanent damage If not ASAP) - CxR If malignancy suspected
Treatment of myelopathy
Neurosurgery (laminectomy, microdiscectomy)
Cause of cauda equina syndrome
Occurs in 2% lumber herniation (L4/5 or L5/S1)
Symptoms of cauda equina syndrome
leg weakness with LMN signs - Saddle anaethesia (perianal numbness) - Bladder/bowel dysfunction + Sphincter involvement common
Diagnosis of cauda equina syndrome
MRI cord (diagnostic) - testing Nerve roots/reflexes
Treatment of cauda equina syndrome
ASAP neurosurgery (eg: microdiscectomy, spinal fixation)
Mechanisms of peripheral neuropathy
- Demyelination - Axonal damage - Nerve compression - Vasa nervorum infarction - Wallerian degeneration (nerve cut; distally dies)
What are vasa nervorum?
Small arteries that provide blood supply to peripheral nerves
Aetiology of peripheral neuropathy
Demyelination (mc Guillain Barre,#REF! def) - T2DM - surgery - pathology, eg: infection, endocrine, rheumatoid arthritis
Types of peripheral neuropathy
Mononeuropathy - single Nerve - Mononeuritis multiplex - several individual nerves - polyneuropathy - diffuse, Often symmetrical pathology
Causes of mononeuritis multiplex
Wegeners AIDS/amyloidosis Rheumatoid arthritis DMT2 Sarcoidosis Polyarteritis nodosa Leprosy Carcinomas
Pathophysiology of carpal tunnel syndrome
pressure on median Nerve, passing through carpal tunnel - Nerve roots #REF! - T1
Risk factors of carpal tunnel syndrome
F > M - Hypothyroidism - Acromegaly - Pregnancy - rheumatoid arthritis - Obesity
Symptoms of carpal tunnel syndrome
Gradual onset - Weakness of grip + aching hand/forearm - Parasthesia of the hand - Wasting thenar eminence
Nature of carpal tunnel syndrome pain
Bad at night - Relieved by hanging hand over bed - WAKE and SHAKE
Diagnosis of carpal tunnel syndrome
Phalen’s test - Flex hands at wrist for 1 minute - Parasthesia + pain = +ve Tinel test - Tapping wrist causes tingling Electromyography diagnostic if above tests uncertain
Treatment of carpal tunnel syndrome
Wrist splint at night + steroid injection (Acutely v painful) - last resort = surgical decompression
Wrist drop
Radial Nerve palsy - roots C5 - T1 - Mostly innervates extensor arm muscles
Claw hand
- Ulnar nerve palsy - Nerve roots C8 + T1 - 4th and 5th fingers claw up
Foot drop
common peroneal Nerve palsy - Nerve roots L4 - S2 - Smaller of Two terminal branchers of sciatic Nerve, other one being The tibial Nerve
Trendelenburg sign
Superior gluteal Nerve palsy - Nerve roots S4 - L1
Aetiology of sciatica
L5/S1 lesion due to: - Spinal: IV disc herniation/prolapse - Non spinal: Piriformis syndrome, tumours, pregnancy
Symptoms of sciatica
- Pain from buttock down lateral leg -> pinky toe - Weak plantarflexion + absent ankle jerk
Diagnosis of sciatica
- Exam - can’t do straight leg raise test without pain - MRI cord to confirm
Treatment of sciatica
analgesia + Physio - Neurosurgery
Distribution of polyneuropathy
- “Glove + stocking” distribution - Mostly peripheries affected
Types of polyneuropathy
Mostly motor = Guillain Barre syndrome - Mostly sensory = Diabetic neuropathy
Other causes of polyneuropathy
Vasculitis - malignancy -#REF! deficiency - rheumatoid arthritis
Diagnosis of polyneuroathy
Find an underlying cause through bloods, serology, ESR/CRP
Treatment for polyneuropathy
Analgesia + treat underlying cause (eg: TCA)
Pathophysiology of multiple sclerosis
- Type 4 sensitivity vs myelin basic protein of oligodendrocytes - Leading to demyelination of CNS neurons
Risk factors of multiple sclerosis
females - 20-40 - Autoimmune disease - family history - EBV
What is primary progressive remiting multiple sclerosis?
Gradual deterioration without recovery
Types of multiple sclerosis
Relapsing remiting - common in early stages, often becoming progressive Primary progressive - from disease onset Secondary progressive - following a period of relapsing/remitting disease (75% evolve to this)
Symptoms of multiple sclerosis
- Parasthesia - Blurred vision - Uthoff’s phenomenon - symptoms exacerbated by heat 🚿
Signs of multiple sclerosis
Optic neuritis - Internuclear opthalmoplegia - brain signs - sensory signs - UMN signs (not LMN) - Lhermitte phenomenon - Charcot neurological triad
What is optic neuritis?
- First presenting symptom of multiple sclerosis - Inflamed optic nerve - Can’t see red properly - Usually unilateral
What is internuclear opthalmoplegia?
lateral gaze Impaired - Damaged medial longitudinal fasciculus
What is the lhermitte phenomenon?
Electric shock sensation with neck flexion
Charcot neurological triad
Dysarthria - staccato Speech - Nystagmus - repetitive involuntary eye movement - Intention tremor
Diagnosis of multiple sclerosis
Mcdonald criteria - 2 ≤ attacks disseminated in time and space (separate events and different parts of the CNS affected) Also: - MRI brain and cord is diagnostic - CSF from lumbar puncture (oligoclonal IgG bands) - Evoked potentials - delayed reactions to stimuli
What does an MRI brain and cord show for multiple sclerosis
Dissemination in space and time - Space - Where is white demyelination? - Time - give gadolinium contrast to show how long these have been there for
Treatment of multiple sclerosis
- Acutely (in episodes) - IV Methylprednisolone - Prophylaxis - beta inteferon (DMARD; biologic)
Where does UMN lesion come from?
Precentral gyrus - to Anterior spinal cord
UMN lesions signs
Everything UP - Hypertonia; rigidity + spasticity (rigid w movement) - Hyperreflexia - No fasciculation - Babinski positive - Arms: power of flexors > extensors - Legs: power of flexors < extensors
LMN lesion signs
Everything DOWN: - Hypotonia (flaccid) + muscle wasting - Hyporeflexia - Fasciculations - Babinski negative - Generall low power
Where does an LMN lesion come from
Antispinal cord - to The muscles innervated
Presentation of MND
- Mixed UMN + LMN signs - No eye, sensory, cerebellar or Parkinson’s signs
Decussation of UMN
Decussation - lateral, 90% fibres No decussation - anterior, 10% fibres
Risk factors for MND
- Male - Family history (SOD-1 mutation) - Increasing age
What is amyotrophic lateral sclerosis (ALS) ?
- Most common classification of MND - Can progress to bulbar palsy - May see “split hand sign” - disproportionately high wasting of thenar muscles compared to hypothenars
Types of ALS
progressive muscular atrophy - LMN only - primary lateral sclerosis - UMN only
What is progressive bulbar palsy?
- CN 9-12 affected - Worst progrnosis, high chance of respiratory failure
Diagnosis of MND
Mainly Clinical - Electromyography shows fibrillation potentials - due to denervation of muscles with LMN dysfunction
Treatment of MND
MDT management - Riluzole (antiglutaminergic) - Supportive - Physio and breathing support If necessary
Complications of MND
resp failure - Aspiration pneumonia - Swallowing failure
Types of primary brain tumour
- Glioma, mc type: astrocytoma (90%) (2nd mc paediatric cancer after ALL) - Oligidodendrocytoma - Meningioma + Schwannoma
Secondary brain tumours
Much More common, mets form NSCLC (mc) + SCLCBreastMelanomaRenal cell (RCC) Gastric cancerTesticularColorectal
Treatment of secondary brain tumours
- Often metastasised = grade 3/4 (severe) - Chemo, palliative care
WHO grading for astrocytomas
1-4 1 = benign 4 = globlastoma (v bad prognosis, death within 1 year)
Symptoms of primary brain tumours
High ICP signs including headaches - Focal neurology - Epileptic seizures - Lethargy and weight loss
Diagnosis of primary brain tumours
MRI head to locate tumour - Then biopsy to determine grade - no lumbar puncture because High ICP of undetermined cause = massive CI
Treatment of primary brain tumours
craniotomy - + chemo before/during/after surgery - Steroids (eg: dexamethasone) May help
What is meningitis?
infection of The meninges of The brain - Notifiable to Public Health England
Causes of meningitis
- Viral (mc, less severe) -> enteroviruses (eg: coxsackie) and HSV-2, VZV - Bacterial (lc, very severe) -> mainly s.pneumoniae + n.meningitidis
Risk factors for meningitis
Extremes of age - Immunocompromised - Crowded environments - non-vaccinated
Bacterial causes of meningitis in neonates (0-3 months)
Group B alpha haem strep (s.agalactiae) - Listeria - E.coli
Bacterial causes of meningitis in infants (3 months - 6 years)
S.pneumoniae - N.meningitidis
Bacterial causes of meningitis in non-neonates
S.pneumoniae - N.meningitidis
Bacterial causes of meningitis in the elderly (60+ years)
S.pneumoniae - N.meningitidis - Listeria
Meningitis caused by n.meningitidis
- Gram negative diplococcus - Vaccines available; men B + C, MenACWY - Non blanching purpuric rash (meningococcal septicemia -> DIC -> v easy bleeds)
Meningitis caused by s.pneumoniae
- Gram positive diplococcus in chains - PCV vaccine - 25% mortality
Meningitis caused by Group B strep
- Gram positive coccus in chains - Most common cause of neonatal meningitis - Because it colonises maternal vagina !!!
Meningitis caused by listeria monocytogenes
gram positive bacillus - Affects Extremes of age and maternal (pregnant ladies) - Found in cheese 🪤
Presentation of meningitis
- Meningism - headache, neck stiffness, photophobia, fever - Kernig - can’t extend knee without pain when hip is flexed - Brudzinski - when neck is flexed, knees and hips automatically flex - Pyrexia
Diagnosis of meningitis
- Lumbar puncture + CSF analysis (contraindicated in high ICP due to tentorial herniation/coning risk) - Sample taken from L3/4 and analysed
CSF sample in meningitis caused by bacteria
- High opening pressure - Cloudy yellow - Neutrophilia - High protein (>1g/L) - Low glucose (<50% serum levels)
CSF sample in meningitis caused by virus
- Normal opening pressure - Clear, normal appearance - Lymphocytosis - Normal/high proteins (<1g/L) - Glucose >60% serum level
CSF sample in meningitis caused by fungus/TB
Same as bacteria but also fibrinous and high lymphocytes instead of neutrophils
Treatment for viral meningitis
Nothing If enteroviruses - Aciclovir If HSV Or VZV
Contact tracing for meningitis
- Antibiotic prophylaxis for contacts with 7+ days prolonged contact preceding symptoms (eg: cohabitation) - One off dose of ciprofloxacin
What is meningococcal disease?
Any illness caused by bacteria called Neisseria meningitidis (n.meningitidis)
Complications of meningitis
DIC (meningococcal septicaemia) - Waterhouse friedrichsen syndrome (adrenal insufficiency caused by intraadrenal haemorrhage as a result of meningococcal DIC)
What is encephalitis?
Viral infection of brain parenchyma
Aetiology of encephalitis
- 95% of cases: HSV-1 - Others: CMV, EBV, HIV, toxoplasmosis (close contact with cats; parasitic infection)
Risk factors of encephalitis
Immunocompromised - Extremes of age
Symptoms of encephalitis
- Fever - Headache - Encephalopathy - Focal neurology (temporal lobe mc affected - eg: aphasia)
Encephalitis that presents with meningism symptoms
Meningo-encephalitis (2-in-1 offer🛍)
Diagnosis of encephalitis
- CSF may show veraemia (viruses in blood, high lymphocytes, consider PCR) - MRI head = unilateral usually temporal encephalitis - Also non-specific EEG firing of 2Hz periodically
Treatment for encephalitis
Aciclovir (works well against HSV)
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- Caudate nucleus 2. Putamen 3. Globus pallidus 4. Subthalamic nucleus 5. Substantia nigra
Visual pathway
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CN3 - Oculomotor
- Motor to MR, SR, IO, LPS - Carries parasympathetic fibres into the orbit -> constrict the pupil
Pupillary light reflex
Afferent limb (input) = CN2 Efferent limb (output) = Parasympathetic fibres in CN3 To test: Shine light into one eye Ipsilateral pupil constricts = direct response Contralateral pupil constricts = consensual response
What is acoustic neuroma?
Also called vestibular schwannoma - Peogressive Unilateral Hearing loss and dizziness
Pathophysiology of intracerebral haemorrhage
Spontaneous due to aneurysm Or vessel rupture - small perforating vessels prone to rupture, especially If hypertensive
Diagnosis of intracerebral haemorrhage
acute (fresh) bleed is hyperdense on CT - blood seen in The substance of The brain - Mass effect seen If large (eg: midline shift)
What does the brainstem include
Midbrain - pons - medulla oblongata Contains Ascending and descending tracts
Function of the cerebellum
Balance, posture and motor coordination - Operates subconciously
Differential diagnosis of stroke
Epileptic seizure - space occupying lesion - infection - Metabolic problems: thyroid, diabetes - MS - Functional neurological disorder - Migraine
Aetiology of brain tumours
- Majority no cause found - Ionising radiation (radiotherapy) - 5% family history - associated genetic syndromes eg, neurofibromatosis, Von Hippel-Lindau disease, tuberose sclerosis - Immunosuppression (CNS lymphoma)
Symptoms of vertebrobasilar artery stroke
Cerebellar signs - Reduced consciousness - Quadriplegia Or hemiplegia
Weber’s syndrome
Midbrain infarct - branches of PCA - Oculomotor palsy - Contralateral hemiplegia
What to investigate for if a young person presents with stroke
Aortic dissection
Non-movement related symptoms of Parkinson’s disease
Autonomic problems - Constipation - Increased urinary frequency (but incontinence not typical) - Anosmia seen early (loss of sense of smell) Depression and anxiety Dementia
Parkinsonian tremors vs essential tremors
Parkinsons: unilateral resting/pill rolling tremor that usually affects limbs (can become bilateral) Essential tremor: bilateral symmetrical active tremor that worsens with movement
Gait patterns in Parkinson’s
Reduced armswing - Shuffling gait - Festination - Stooped posture
Treatment for wrist drop and claw hand
Splint + simple analgaesia
