Neurology Flashcards
Describe symptoms of an extradural bleed
- developed a headache after head trauma
- confused and drowsy
- difficult to rouse
- biconvex shape on CT
Describe presentation of subarachnoid bleeding
- sudden onset
- severe thunderclap headache
- occurs due to strenuous activity
What is Guillan-Barré syndrome?
- an acute paralytic polyneropathy
- affects peripheral nervous system
- symptoms peak after 2-4 weeks, recovery can take months-years
What causes Guillan-Barré syndrome?
- triggered by infection
- associated with:
- campylobacter jejuni (MC)
- cytomegalovirus
- Epstein-Barr virus
What is the pathophysiology behind Guillan-Barré syndrome?
- occurs due to molecular mimicry
- B cells create antibodies against antigens on the pathogen
- these antibodies match proteins on nerve cells
- Abs then target myelin sheath of motor nerve cell or nerve axon
How does Guillan-Barré syndrome present?
- symmetrical ascending weakness (starting at feet)
- reduced reflexes
- peripheral loss of sensation/neuropathic pain
- progresses to cranial nerves and causes facial weakness
How is Guillan-Barré syndrome diagnosed?
- Brighton criteria
- nerve conduction studies
- lumbar puncture for CSF: raised protein, normal cell count and glucose
How is Guillan-Barré syndrome managed?
- IV immunoglobulins
- plasma exchange
- supportive care
- VTE prophylaxis
What is multiple sclerosis?
- chronic and progressive condition involving demyelination of neurones in the CNS
What is the epidemiology of multiple sclerosis?
- young adults (under 50)
- more common in women
- symptoms improve in pregnancy and postpartum
What is the pathophysiology of multiple sclerosis?
- myelin made by Schwann cells (PNS) and oligodendrocytes (CNS)
- immune cells infiltrate and damage myelin > inflammation > symptoms
- re-myelination can occur in early disease, is incomplete in late disease > permanence
What is the aetiology of multiple sclerosis?
- genetic
- EBV
- low vit D
- smoking
- obesity
Why do symptoms of MS change over time?
- lesions vary in location over time
- different nerves are affected and symptoms change
- early course: relapsing-remitting attacks
How is multiple sclerosis managed?
- acute episodes: IV methylprednisolone
- DMDs: β interferon
- mitoxantrone
What optical symptoms occur with multiple sclerosis?
- double vision: abducens (VI) lesions
- internuclear opthalmoplegia: problems with coordinating eye movements (III, IV, VI)
- conjugate lateral gaze disorder: affected eye cannot abduct (VI)
How is multiple sclerosis diagnosed?
- progressive symptoms over a year
- or 2 attacks disseminated in time and space
- MRI brain + cord showing lesions
- LP shows oligoclonal IgG bands in CSF
What is optic neuritis?
- unilateral reduced vision over hours to days
- central scotoma (enlarged blind spot)
- impaired colour vision
- pain on eye movement
- relative afferent pupillary defect
What is the general presentation of multiple sclerosis?
- sensory and cerebellar ataxia
- tremors
- incontinence
- limb paralysis
- trigeminal neuralgia, numbness and paresthesia
What are the types of disease course of multiple sclerosis?
- relapsing-remitting: episodes of disease followed by recovery - can be active and/or worsening
- 1º progressive: gradual deterioration without recovery
- 2º progressive: relapsing-remitting > worsening and incomplete remission
What are differential diagnoses for multiple sclerosis?
- SLE, Sjrogen’s, encephalomyelitis
- Lyme’s, syphilis, AIDS
What is Parkinson’s disease?
- progressive reduction of dopamine in the basal ganglia leading to movement disorders
- substantia nigra produces dopamine
- asymmetrical symptom
How is Parkinson’s diagnosed and what is the classic triad?
- clinically based on symptoms
- resting tremor, rigidity, bradykinesia
- DaTscan
What are the symptoms of Parkinson’s?
- unilateral tremor: 4-6Hz
- cogwheel rigidity: jerky movement
- bradykinesia: shuffling gait, difficulty initiating movement, reduced facial expression
- anosmia
- postural instability
How is Parkinson’s managed?
- Levodopa + carbidopa (decarboxylase inhibitor)
- dopamine agonist e.g. bromocriptine
- COMT inhibitors e.g. entacapone: metabolises L-dopa
- Monoamine oxidase B inhibitors - rasagiline
How does levodopa work and what are the associated side effects?
- synthetic dopamine
- taken alongside decarboxylase inhibitor e.g. carbidopa
- becomes less effective over time
- leads to dyskinesias e.g. dystonia, chorea, athetosis
What are the risk factors and epidemiology of Parkinson’s?
- family history
- male
- inc age
- e.g. 70y/o male
What is Huntington’s chorea and what is the pathophysiology?
- autosomal dominant condition with full penetrance
- trinucleotide repeat disorder in HTT in chromosome 4
- lack of GABA and excessive nigrostriatal pathway
What is genetic anticipation?
- more trinucleotide repeats leads to earlier onset of disease and increased severity
When does Huntington’s present and what is the prognosis?
- asymptomatic until age 30-50
- life expectancy: 15-20yrs after onset of symptoms
How does Huntington’s present?
- cognitive, psychiatric and mood problems > movement disorder
- chorea
- eye movement disorders
- dysarthria and dysphagia
- depression
How is Huntington’s diagnosed?
- genetic testing with pre and post-test counselling
- diagnosis if > 35 CAG repeats
How is Huntington’s managed?
- antipsychotics e.g. olanzapine
- benzodiazepines e.g. diazepam
- dopamine-depleting agents e.g. tetrabenzine
- antidepressants
What is myasthenia gravis?
- autoimmune condition causing muscle weakness
- progressively worse weakness with activity which improves with rest
- mostly affects proximal muscles and small muscles of head and neck
How is myasthenia gravis diagnosed?
- testing for antibodies: acetylcholine receptor (Ach-R) and muscle-specific kinase (MuSK)
- Edrophonium test
What is the edrophonium test for myasthenia gravis?
- IV dose of edrophonium chloride
- normally cholinesterase enzymes break down Ach but edrophonium blocks the enzymes
- stops Ach breakdown and and inc Ach levels
- relieves weakness temporarily
What is the epidemiology of myasthenia gravis?
- women under 40
- men over 60 (more related to thymoma)
What is the pathophysiology behind myasthenia gravis?
- Ach-R antibodies bind to postsynaptic NMJ receptors
- Ach unable to bind, stimulate receptor and trigger muscle contraction
- more used during activity and so more are blocked
- Abs activate complement system leading to damage at postsynaptic membrane
How does myasthenia gravis present?
- extraocular muscle weakness > diplopia
- eyelid weakness > ptosis
- dysphagia
- jaw fatigue
- slurred speech
- facial weakness
How can myasthenia gravis be examined?
- repeated blinking > ptosis
- prolonged upward gazing > diplopia
- repeated abduction of one arm > unilateral weakness
How is myasthenia gravis managed?
- reversible Ach inhibitors: pyridostigmine
- immunosuppression
- thymectomy
- monoclonal Abs: rituximab
What is myasthenic crisis?
- complication causing acute worsening of symptoms
- triggered by another illness e.g. resp tract
- can lead to resp failure > ventilation
- treatment with IVIG and plasma exchange
What is the presentation of trigeminal neuralgia?
- intense facial pain
- comes on spontaneously, can last seconds to hours
- electricity-like shooting pain
How is trigeminal neuralgia treated?
- carbamazepine
What is the pathophysiology of trigeminal neuralgia?
- can affect any combination of V1, V2 and V3
- 90% cases are unilateral
- triggers: cold weather, spicy food, caffeine, citrus
What are the 3 branches of the trigeminal nerve?
- V1: ophthalmic
- V2: maxillary
- V3: mandibular
How do tension headaches present?
- mild ache across forehead in band like pattern
- muscle ache in frontal, temporalis and occipitalis muscles
- come on and resolve gradually: no visual changes
What are the causes of tension headaches?
- alcohol
- depression
- dehydration
- stress
- skipping meals
What are cluster headaches?
- severe and unbearable unilateral headaches
- usually around the eye
- crescendo pain which may affect temples
What are the symptoms of cluster headaches?
- unilateral
- red, swollen, watering eye
- pupil constriction
- ptosis
- nasal discharge
- facial sweating
What is the frequency of cluster headaches?
- attacks lasting 15 mins - 3hrs
- may suffer multiple attacks per day for weeks or months
- followed by pain free period lasting 1-2 years
Who is the typical patient to suffer from cluster headaches?
- 30-50 y/o male smoker
- attacks triggered by: alcohol, strong smells, exercise
What are the types of migraines?
- migraine with or without aura
- silent migraine (with aura but without headache
- hemiplegic migraine
What is aura?
- visual changes
- sparks in vision
- blurring lines
- lines across vision
- loss of visual field
How do triptans work?
- 5HT receptor agonists (serotonin)
- cause vasoconstriction in artery smooth muscle
- inhibit peripheral pain receptors
- reduce neuronal activity in CNS
What are the symptoms of migraine?
- pounding/throbbing
- usually unilateral
- photophobia and phonophobia
- nausea and vomiting
What are migraine triggers?
- stress
- bright lights
- strong smells
- dehydration
- menstruation
- abnormal sleep patterns
- certain foods e.g. chocolate, cheese, caffeine
What is the treatment for migraine?
- paracetamol
- triptans e.g. sumatriptan
- NSAIDs
- antiemetics
What is prophylaxis for migraine?
- headache diary
- propanolol, topiramate, amitriptyline
- acupuncture
- riboflavin
What is epilepsy?
- an umbrella term for a condition where there is a tendency to have seizures
What is a seizure?
- a transient episode of electrical activity due to abnormally excessive or synchronous neuronal activity within the brain
How is epilepsy diagnosed?
- electroencephalogram: electrical activity in brain
- MRI brain
What is a generalised tonic-clonic seizure?
- loss of consciousness with muscle tensing (tonic) and muscle jerking (clonic) movements
- post-ictal period
- limb contraction, extension, back arching and - usually last 2-3 minutes
- ictal cry: sound resulting from chest contraction
What is an absence seizure?
- commonly in school aged children
- becomes blank and stares into space then abruptly returns to normal
- unaware of their surroundings and unresponsive but still conscious
- Episodes last 10-20 seconds and can disappear with age
What are symptoms of an anterior circulation dominant hemisphere stroke?
- usually in left hemisphere
- expressive and receptive dysphasia
- dyslexia
- dysgraphia
What are general symptoms of an anterior circulation stroke?
- hemiparesis
- hemisensory loss
- visual field defect (homonymous hemianopia withOUT macular sparing)
What are symptoms of an anterior circulation non-dominant hemisphere stroke?
- anosognosia
- visuospatial dysfunction: geographical agnosia, dressing and constructional apraxia
What are symptoms of a posterior circulation stroke?
- often affects cerebellum + occipital lobe
- clumsiness, difficulty walking in straight line
- visual disturbance
- slurred speech
- headache, vomiting
What investigations are done for stroke?
- 1st line: CT head
- gold: diffusion weighted MRI
- blood test
- carotid doppler
What is the management for stroke?
- aspirin 300mg stat and continued for 2 weeks
- thrombolysis with alteplase (TPA) in 4.5 hr window
- keep BP high to avoid reduced perfusion
What are the secondary prevention guidelines for stroke?
- Clopidogrel 75mg once daily
- Atorvastatin 80mg started (not immediately)
- Carotid endarterectomy (>50%) or stenting
- Treat modifiable risk factors
What is subarachnoid haemorrhage?
- bleeding into subarachnoid space between Pia mater and arachnoid membrane (where CSF is)
- usually due to ruptured cerebral aneurysm
What are the symptoms of a subarachnoid haemorrhage?
- thunderclap headache described like being hit on the back of the head
- neck stiffness
- photophobia
- visual changes
- neurological symptoms
What is the presentation of brain tumours?
- headache
- seizures
- focal neurological symptoms
- other non-focal symptoms e.g. cognitive problems or behavioural changes
What are the symptoms of a raised ICP headache?
- woken by headache
- worse in the morning, lying down
- exacerbated by coughing, sneezing, drowsiness
- nausea and vomiting
Which cancers commonly metastasise to the brain?
- lung
- breast
- renal cell carcinoma
- melanoma
What are the types of gliomas?
- astrocytomas
- oligodendroglioma
- ependymoma
- grade 1 are benign
- grade 4 are most malignant: glioblastoma
What is the treatment for brain tumours?
- surgery: early resection
- combined radiotherapy and chemotherapy
What is motor neurone disease?
- progressive, ultimately fatal condition
- motor neurones stop functioning
What are the types of motor neurone disease?
- amyotrophic lateral sclerosis (ALS)
- progressive bulbar palsy
- progressive muscular atrophy
- primary lateral sclerosis
What is the pathophysiology behind motor neurone disease?
- progressive degeneration of upper and lower motor neurones
- sensory neurones spared
What are risk factors for motor neurone disease?
- genetic
- smoking
- SOD-1 mutation
- exposure to heavy metals and pesticides
What is the presentation of motor neurone disease?
- progressive weakness of muscles affecting limbs, trunk, face, speech
- weakness first noticed in upper limbs: fatigue when exercising
- dysarthria
- mixed LMN and UMN signs
What are signs of lower motor neurone disease?
- muscle wasting
- reduced tone
- fasciculations
- reduced reflexes
- Babinski -ve
What are the signs of upper motor neurone disease?
- increased tone or spasticity
- brisk reflexes
- no fasciculation
- babinski +ve: upgoing plantar responses