Neurology Flashcards
What is the aetiology of an ischaemic stroke?
- Small vessel occlusion/ thrombosis in situ
- Cardiac emboli from AF, MI or infective endocarditis
- Large artery stenosis
- Atherothromboembolism
- Hypoperfusion, vasculitis, hypervisocity
What is the aetiology of a haemorrhagic stroke?
CNS bleeds due to:
- Trauma
- Aneurysm rupture
- Anticoagulation
- Thrombolysis
- Carotid artery dissection
- Subarachnoid haemorrhage
What is the pathophysiology of an ischaemic stroke?
- Arterial disease and atherosclerosis
- Thrombosis occurs at the site of an atheromatous plaque in the carotid/ vertebral/ cerebral arteries
- Large artery stenosis acts as an embolism source rather than occluding the vessel
What is the pathophysiology of a haemorrhagic stroke?
Hypertension resulting in micro aneurysm rupture
What are the risk factors for a stroke?
- Male
- Black or Asian
- Hypertension
- Past TIA
- Smoking
- Diabetes mellitus
- Increasing age
- Heart disease
- Alcohol
- Polycythaemia
- AF
- High cholesterol
- Combined oral contraceptive pill
- Vasculitis
- Infective endocarditis
What is the clinical presentation of an anterior cerebral artery stroke?
- Leg weakness more likely than arm weakness
- Sensory disturbances in legs
- Gait apraxia
- Truncal apraxia
- Incontinence
- Drowsiness
What is the clinical presentation of a middle cerebral artery stroke?
- Contralateral arm and leg weakness
- Contralateral sensory loss
- Hemianopia
- Aphasia
- Dysphasia
- Facial droop
What is the clinical presentation of a posterior cerebral artery stroke?
- Contralateral homonymous hemianopia
- Cortical blindness (eyes healthy but brain issues)
- Visual agnosia (can see but can’t interpret)
- Prosopagnosia (can’t see faces)
- Problems naming and distinguishing colours
- Unilateral headache
What is the clinical presentation of a posterior circulation stroke?
- More catastrophic (wide region supplied)
- Motor deficits
- Dysarthria and speech impairment
- Vertigo, nausea, vomiting
- Visual disturbance
- Altered consciousness
What are the differential diagnoses of a stroke?
- Always exclude hypoglycaemia
- Migraine aura
- Focal epilepsy
- Intracranial lesion
- Syncope due to arrhythmia
How is a stroke diagnosed?
- Urgent CT/ MRI head before treatment to rule out haemorrhagic before starting thrombolysis
- Pulse, BP and ECG to look for AF
- Bloods – thrombocytopenia and polycythaemia on FBC; hypoglycaemia on blood glucose
How is a stroke managed?
- Maximise reversible ischaemic tissue
- Thrombolysis up to 4.5h after onset of symptoms (give tissue plasminogen activator e.g. IV alteplase then antiplatelet therapy 24h later e.g. clopidogrel)
- If time of onset is unknown, then daily aspirin and lifelong clopidogrel
In haemorrhagic:
- No antiplatelets
- Control hypertension
- Reduced ICP (manually or with diuretics)
- May need surgery
Risk management for stroke prevention:
- Platelet treatment (e.g. aspirin with clopidogrel)
- Cholesterol treatment
- AF treatment (e.g. warfarin)
- BP treatment (e.g. Ramipril)
What is the aetiology of a TIA?
- Small vessel occlusion
- Atherothromboembolism
- Cardioembolism
- Hyperviscosity
- Can result from hypoperfusion in younger people
What is the pathophysiology of a TIA?
- Cerebral ischaemia resulting in a lack of O2 and nutrients to the brain causing cerebral dysfunction
- Period of ischaemic is short lived and symptoms rarely last more than 15m and resolve before irreversible cell death
- Gradually progressing symptoms suggests a different pathology e.g. demyelination, tumour or migraine
What are the risk factors of a TIA?
- Increasing age
- Hypertension
- Smoking
- Diabetes
- Heart disease (valvular, ischaemic, AF)
- Past TIA
- Raised packed cell volume
- Peripheral arterial disease
- Combined oral contraceptive pill
- Hyperlipidaemia
- Excess alcohol
- Clotting disorder
- Vasculitis e.g. SLE, GCA
What is the clinical presentation of an anterior circulation TIA?
- Weak, numb contralateral leg ± similar arm symptoms
- Hemiparesis (weakness on an entire side of the body)
- Hemi sensory disturbance
- Dysphagia
- Sudden transient loss of vision in one eye
What is the clinical presentation of a posterior circulation TIA?
- Double vision
- Vertigo
- Vomiting
- Choking and dysarthria
- Ataxia
- Hemisensory loss
- Hemianopia vision loss
- Loss of consciousness (rare)
- Transient global amnesia (episode of confusion/ amnesia lasting several hours followed by complete recovery)
- Tetraparesis (muscle weakness in all 4 limbs)
What are the differential diagnoses of a TIA?
- Impossible to differentiate from a stroke until a full recovery has been made
- Hypoglycaemia\migraine aura
- Focal epilepsy
- Intracranial lesion
- Syncope
- Todd’s paralysis
- Retinal or vitreous haemorrhage
- GCA
How is a TIA diagnosed?
- Often based solely on description
- Bloods: FBC (for polycythaemia), ESR (for vasculitis), glucose (for hypoglycaemia), creatinine, electrolytes, cholesterol
- Carotid artery doppler ultrasound for stenosis/ atheroma
- CT/ MRI head
- ECG (look for AF or evidence of MI ischaemia)
- CT or diffusion weighted MRI
- Echocardiogram/ cardiac monitoring to assess for a cardiac cause
How is a TIA managed?
- Immediate aspirin and dipyridamole for 2 weeks then a lower dose
- P2Y12 inhibitor long term
- Anticoagulant if they have AF, mitral stenosis or recent septal MI
- Statin long term
- Control cardiovascular risk factors
What is the aetiology of a subarachnoid haemorrhage?
- Rupture of saccular aneurysms (e.g. Berry aneurysm) = rupture of the junction of the posterior communicating artery with the internal carotid or the anterior comm with the arterial cerebral
- Arteriovenous malformation = vascular development malformation
- Rare = bleeding disorder, mycotic aneurysms, acute bacterial meningitis, tumours
What is the pathophysiology of a subarachnoid haemorrhage?
Most common cause is a ruptured aneurysm which leads to tissue ischaemia and rapidly raised ICP
What are the risk factors of a subarachnoid haemorrhage?
- Hypertension
- Known aneurysm
- Family history
- Disease that predispose to aneurysm (polycyctic kidney disease, Ehler’s Danlos, coarctation of aorta)
- Smoking
- Bleeding disorders
- Post-menopausal decreased oestrogen
What is the clinical presentation of a subarachnoid haemorrhage?
- Sudden onset severe occipital headache (incredibly painful)
- Vomiting, collapse, seizures, coma often follow
- Depressed level of consciousness
- Coma/drowsiness may last for days
- Neck stiffness
- Kernig’s signs (unable to extend leg at the knee when the thigh is flexed)
- Brudzinski’s sign (when neck is manually flexed, patient will flex hips and knees)
- Retinal and vitreous bleeds
- Papilloedema
- Vision loss or diplopia
- Focal neurology
- Marked increase in BP (reflex following haemorrhage)
- Sentinel headache (may present earlier, so ask about it in history)
What are the differential diagnoses of a subarachnoid haemorrhage?
- Must be differentiated from a migraine
- Meningitis
- Intracranial bleeds
- Cortical vein thrombosis
How is a subarachnoid haemorrhage diagnosed?
- ABG to exclude hypoxia
- Head CT = gold standard (seen as a ‘star shaped’ lesion)
- CT angiogram if aneurysm is confirmed to see extent
- Lumbar puncture
How is a subarachnoid haemorrhage managed?
specific interventions
- Refer to neurosurgery immediately
- IV fluids to maintain cerebral perfusion
- Ca2+ blocker to reduce vasospasm and morbidity
- Endovascular coiling – FIRST LINE when angiography shows aneurysm
- Surgery – intracranial stents and balloon remodelling for wide-necked aneurysms
What is the aetiology of a subdural haemorrhage?
Trauma due to deceleration from violent injury or dural metastases results in bleeding from the bridging veins between cortex and venous sinuses
What is the pathophysiology of a subdural haemorrhage?
- Bridging veins bleed and form a haematoma between dura and arachnoid, reducing pressure and stopping the bleeding
- The haematoma starts to autolyse due to the massive increase in oncotic and osmotic pressure, so water is sucked into the haematoma, causing it to enlarge
- ICP rises gradually over many weeks
- Midline structures shift away from the side of the clot and if untreated can result in herniation and coning
What are the risk factors of a subdural haemorrhage?
- Traumatic head injury, cerebral atrophy and increasing age (all make bridging veins more vulnerable)
- Alcoholism, anticoagulation and physical abuse in infancy
What is the clinical presentation of a subdural haemorrhage?
- Interval between injury and symptoms can be days to weeks to months
- Fluctuating levels of consciousness ± insidious physical or intellectual slowing
- Sleepiness
- Headache
- Personality change
- Unsteadiness
- Signs of raised ICP e.g. headache, vomiting, nausea, seizures and raised BP
- Focal neurology e.g. hemiparesis or sensory loss
- Occasionally seizures
- Stupor, coma and coning may follow
- Symptoms will develop much slower in the elderly due to decrease in brain weight
What are the differential diagnoses of a subdural haemorrhage?
- Stroke
- Dementia
- CNS masses e.g. tumours or abscess
- Subarachnoid haemorrhage
- Extradural haemorrhage
How is a subdural haemorrhage diagnosed?
- CT head: diffuse spreading, hyperdense crescent shaped collection of blood over 1 hemisphere (sickle/crescent shaped differentiates subdural from extradural)
- MRI head for subacute haematomas and smaller haematomas
How is a subdural haemorrhage managed?
- Assess and manage ABCs
- Prioritise head CT
- Stabilise patient
- Refer to neurosurgeons
- Address cause of trauma
- IV mannitol to reduce ICP
What is the aetiology of an extradural haemorrhage?
Most commonly due to a traumatic head injury resulting in fracture of the temporal or parietal bone causing laceration of the middle meningeal artery, typically after trauma to the temple
What is the pathophysiology of an extradural haemorrhage?
Blood accumulates rapidly over minutes to hours between the bone and the dura
What is the clinical presentation of an extradural haemorrhage?
- Characteristic history: head injury, brief post-traumatic loss of consciousness or initial drowsiness, lucid interval while haematoma is still small
- Severe headache, nausea and vomiting, confusion and seizures (due to rising ICP) ± hemiparesis with brisk reflexes
- Ipsilateral pupil dilates, coma deepens, bilateral limb weakness and breathing becomes deep and irregular
- Decreased GCS and coning (brain herniates through foramen magnum)
- Death from respiratory arrest if surgical intervention not fast enough
- Bradycardia and raised BP are late signs
What are the differential diagnoses of an extradural haemorrhage?
- Epilepsy, carotid dissection and carbon monoxide poisoning
- Subdural haematoma, subarachnoid haemorrhage, meningitis
How is an extradural haemorrhage diagnosed?
- CT head = gold standard (shows hyperdense haematoma)
- Skull XR to see fracture lines (fracture would increase extradural haemorrhage risk)
How is an extradural haemorrhage managed?
- ABCDE emergency management (assess and stabilise patient)
- IV mannitol for increased ICP
- Refer to neurosurgery (clot evacuation ± litigation of bleeding vessel)
- Maintain airway via intubation and ventilation in unconscious patient
What is the aetiology of epilepsy?
- 2/3 idiopathic (often familial)
- Cortical scarring (head injury years before onset, cerebrovascular disease e.g. cerebral infraction, haemorrhage, CNS infection e.g. meningitis, encephalitis)
- Space-occupying lesion e.g. tumour
- Stroke
- Tuberous sclerosis
- AD or other dementia
- Alcohol withdrawal
What is the pathophysiology of primary generalised seizures?
- Simultaneous onset of electrical discharge throughout the whole cortex with no localising features referable to only one hemisphere
- Bilateral symmetrical and synchronous motor manifestations
- Always associated with a loss of consciousness
What is the pathophysiology of partial/ focal seizures?
- Focal onset with features referable to a part of one hemisphere e.g. temporal lobe
- Often seen with underlying structural disease
- Electrical discharge is restricted to a limited part of the cortex of one cerebral hemisphere
- These may later become generalised (e.g. secondary generalised tonic-clonic seizures)
What are the risk factors of epilepsy?
- Family history
- Premature baby small for age
- Abnormal blood vessels in the brain
- AD or other dementia
- Use of drugs e.g. cocaine
- Stroke/ brain tumour/ infection
What are the 5 types of primary generalised seizure?
- Generalised tonic-clonic
- Typical absence seizure
- Myoclonic seizure
- Tonic seizure
- Atonic seizure
What is the clinical presentation of the 5 types of primary generalised seizure?
(Generalised tonic-clonic, typical absence, myoclonic, tonic, atonic)
GENERALISED TONIC-CLONIC
- Often no aura
- Loss of consciousness
- Tonic phase = rigid stiff limbs (patient will fall to the floor if standing)
- Clonic phase = generalised bilateral, rhythmic muscle jerking lasting for seconds to minutes
- Eyes remain open and tongue often bitten
- May be incontinence of urine/faeces
- Followed by a period of drowsiness, confusion or coma for several hours
TYPICAL ABSENCE SEIZURE
- Usually in childhood
- Ceases activity, stares and pales for a few seconds (suddenly stops talking mid-sentence then carries on where they left off)
- Often don’t realise they’ve has an attack
MYOCLONIC SEIZURE
- Sudden isolated jerk of a limb, face or trunk
- Patient may be thrown suddenly to the ground or have a violently disobedient limb
TONIC SEIZURE
- Sudden sustained increased tone with a characteristic cry/grunt
- Intense stiffening of body
- Stiffening not followed by jerking
ATONIC SEIZURE
- Sudden loss of muscle tone and cessation of movement resulting in a fall
What are the 2 types of partial/ focal seizures?
- Simple partial seizure
- Complex partial seizure
What is the clinical presentation of the 2 types of partial/ focal seizures?
(General symptoms for simple partial seizures and symptoms for each lobe for complex partial seizures)
SIMPLE PARTIAL SEIZURE
- Not affecting consciousness or memory
- Awareness is unimpaired with focal motor, sensory, autonomic or psychic symptoms
- No post-ictal symptoms
COMPLEX PARTIAL SEIZURE
- Affecting awareness or memory before, during, or immediately after the seizure
- Most commonly arise from the temporal lobe
- Temporal lobe → aura (deja-vu, auditory hallucinations, funny smells, fear), anxiety or out of body experience, automatisms (lip smacking, chewing, fiddling), post-ictal confusion
- Frontal lobe → motor features (posturing or peddling movements of the leg), Jacksonian march (seizure ‘marches’ up/down the motor homunculus starting in the face/thumb), post-ictal Todd’s palsy (paralysis of limbs involved in seizure for several hours)
- Parietal lobe → sensory disturbances (tingling/ numbness)
- Occipital lobe → visual phenomena (spots, lines or flashes)
What are the differential diagnoses of epilepsy?
- Postural syncope
- Cardiac arrhythmia
- TIA
- Migraine
- Hyperventilation
- Hypoglycaemia
- Panic attacks
- Non-epileptic seizures
How is epilepsy diagnosed?
- Need at least 2 unprovoked seizures occurring >24h apart to make a clinical diagnosis
- EEG – not diagnostic, but used to support a diagnosis, may determine seizure type
- MRI to view hippocampus
- CT head in emergencies to look for tumours and exclude structural abnormalities
- Bloods – FBC, electrolytes, Ca2+, renal function, liver function, urine biochemistry, blood glucose
- Genetic testing e.g. in juvenile myoclonic epilepsy
What are the emergency measures for managing epilepsy?
- ABCDE, glucose, prolonged/ repeated seizure treated with IV/rectal diazepam or lorazepam
- IV phenytoin loading
- Anaesthetic and ventilation if still fitting
How are primary generalised seizures managed?
3 medications for each of generalised tonic-clonic and absence seizures
GENERALISED TONIC-CLONIC
- Oral sodium valproate
- Oral lamotrigine
- Oral carbamazepine
ABSENCE SEIZURE
- Oral sodium valproate
- Oral lamotrigine
- Oral ethosuximide
What are the neurosurgical treatment options for epilepsy?
- Only if drugs not working
- If a single defined cause is found (e.g. hippocampal sclerosis or low-grade tumour) then surgical resection can stop seizures
- Vagal nerve stimulation can reduce seizure frequency and severity
What is the aetiology of Parkinson’s disease?
- Idiopathic
- Drug induced
- Combination of environmental factors (pesticides, methyl-phenyl tetrahydropyridine), Parkinson genes, oxidative stress and mitochondrial dysfunction
What is the pathophysiology of Parkinson’s disease?
- Parkinson’s results from mitochondrial dysfunction and oxidative stress causing progressive degeneration of dopaminergic neurons
- Therefore, reduced striatal dopamine levels due to loss of dopaminergic neurones
- Less dopamine → thalamus is inhibited resulting in a decrease in movement therefore symptoms of Parkinson’s
What is the clinical presentation of Parkinson’s disease?
General, before motor symptoms, classic triad symptoms
- Onset of symptoms is gradual and commonly presents with impaired dexterity or unilateral foot drop
- Onset is asymmetrical (one side is always worse than the other)
- Difficulty with fine movements e.g. doing up buttons
- Parkinsonian gait = stooped posture, small shuffling steps, reduced arm swing, narrow base, difficulty initiating movement and turning and poor balance
- Drooling of saliva and difficulty swallowing is a late feature (can lead to aspiration pneumonia as a terminal event)
- Depression, constipation and increased urinary frequency are all common
Before motor symptoms develop:
- Anosmia
- Depression/ anxiety
- Aches and pains
- REM sleep disorders
- Urinary urgency
- Hypotension and constipation
Classic triad:
- TREMOR
- Worse at rest and often asymmetrical
- Usually most obvious in the hands
- Improved by voluntary movements and made worse by anxiety
- Rhythms gets worse the longer attempted (unique to PD)
- RIGIDITY
- Increased tone in limbs and trunk
- Limbs resist passive extension through movement
- Can cause pain and problems turning in bed
- BRADYKINESIA/HYPOKINESIA
- Slow to initiate movement and low, low-amplitude excursions in repetitive actions
- Reduced blink rate
- Monotonous hypophonic speech
- Micrographia (smaller writing)
What are the differential diagnoses of Parkinson’s disease?
- Benign essential tremor (worse on movement and rare while at rest)
- Multiple cerebral infarcts, Lewy body dementia, drug-induced, Wilson’s disease, trauma, dopamine antagonists