Neurology Flashcards
Where does damage occur between in an UMN lesion?
Damage to motor fibres between pre-central gyrus and anterior horn cells of spinal cord
Where does damage occur between in a LMN lesion?
Damage to motor fibres between anterior horn cells of spinal cord and peripheral nerve
What is the pattern of involvement/distribution in UMN disease?
Pyramidal (affects corticospinal tract)
What is the difference in pattern of sensory loss between UMN and LMN lesions?
UMN: central sensory loss
LMN: glove-stocking/nerve distribution sensory loss
What is the difference in pattern of tendon reflexes and tone between UMN and LMN lesions?
UMN: hyper-reflexia, hyper-tonia
LMN: hypo-reflexia, hypo-tonia
The anterior cerebral artery supplies which parts of the brain? What would be the clinical signs as a result of damage to this artery?
Supplies frontal and medial part of the cerebrum
Weakness and numbness in the contralateral leg + arm symptoms
The middle cerebral artery supplies which parts of the brain? What would be the clinical signs as a result of damage to this artery?
Supplies lateral hemispheres
Contralateral hemiparesis + hemisensory loss in face and arm
Contralateral homonymous hemianopia
Cognitive change - dysphasia, visuo-spatial disturbance
The posterior cerebral artery supplies which parts of the brain? What would be the clinical signs as a result of damage to this artery?
Supplies occipital lobe
Contralateral homonymous hemianopia with macular sparing
List general causes of headache
Raised ICP Infections (meningitis) Giant cell arteritis Haemorrhage, trauma Venous sinus thrombosis Sinusitis Acute glaucoma
List red flags for headache
New onset in over 55 yo Early morning onset Known/previous cancer Immunosuppressed Exacerbated by Valsalva Autonomic upset
What is the commonest cause of intermittent headache?
Migraine
What is the proposed pathophysiology of migraine?
Vascular constriction-dilation, substance P and 5-HT release, trigeminovascular activation, cerebral hyperactivity
All of the above are proposed to play some role
What are some risk factors/aetiology for migraine?
Obesity Excess oestrogen, OCP use Patent foramen ovale Genetics Stress, anxiety Poor diet Physical exertion CHOCOLATE: CHeese, Oral contraceptive, Caffeine, alcohOL, Anxiety, Travel, Exercise
What are some prodromal signs of migraine?
Yawning
Food craving
Change in sleep/appetite/mood
What are some auras that might occur prior to migraine headache?
Visual - central scomata/fortification/hemianopia
Motor - dysarthria, ataxia, ophthalmoplegia
Sensory - paraesthesiae
What is the criteria for diagnosing migraine without aura?
5 or more eps of headache lasting 4-72h
1 of nausea, vomiting, photophobia, phonophobia
2 of unilaterality, pulsating, limiting, worse on activity
What is the treatment for acute migraine?
NSAID (aspirin, ibuprofen)
Anti-emetic
Triptan (rizatriptan)
What drugs can be used for migraine prophylaxis?
Propranolol Topiramate Amitryptilline Valproate Gabapentin
What are some contraindications to triptan use?
IHD, coronary spasm
Uncontrolled BP
Recent lithium/SSRI use
What are trigeminal autonomic cephalgias?
Headaches in a unilateral trigeminal distribution with cranial nerve features
List the main trigeminal autonomic cephalgias?
Cluster headache
Trigeminal neuralgia
SUNCT
Paroxysmal hemicrania
What causes cluster headache?
Superior temporal artery smooth muscle hyperactivity to 5-HT
Describe the presentation of cluster headache, commenting on pain and duration
Rapid onset severe unilateral orbital pain
Watery, bloodshot, oedematous eye with miosis
Lasts 15 mins - 3 hours, occurring once or twice a day
Often nocturnal
Clusters last 4-12 weeks with pain-free periods
How is cluster headache treated?
Acute: high-flow O2, sumatriptan
Prophylaxis: verapamil, topiramate, steroid
What causes trigeminal neuralgia?
Compression of trigeminal nerve root by e.g. aneurysm, tumour, inflammation
Triggered when pressure applied in trigeminal region
Describe the presentation of trigeminal neuralgia, commenting on pain and duration
Paroxysmal intense stabbing pain in V2/V3 region
Facial screwing
Triggered typically by washing, shaving, eating, denchers
Lasts 1 - 90 seconds
Can get up 100 eps a day
How is trigeminal neuralgia treated?
Carbamazepine Lamotrigine Phenytoin Gabapentin Surgical decompression
What is SUNCT?
Short Unilateral Neuralgiform headache with Conjunctival infections and Tearing
How long does SUNCT typically last?
5 seconds - 2 mins
Occurs in frequent bouts
How is SUNCT treated?
Gabapentin
What is paroxysmal hemicrania?
Similar to cluster headache but more frequent and shorter
How is paroxysmal hemicrania treated?
Indomethicin
What are the main aetiology/risk factors behind subarachnoid haemorrhage?
Rupture of saccular aneurysm
AV malformations
Risk factors includes smoking, alcohol excess, hypertension, bleeding disorder, post-menopause, polycystic kidneys, coarctation of aorta
Where are saccular aneurysms usually found?
Junction of posterior communicating and internal carotid
Junction of anterior communicating and anterior cerebral
Birfurcation of middle cerebral artery
List clinical features of subarachnoid haemorrhage
Sudden severe "thunderclap" headache, usually occipital Vomiting Collapse Seizure Coma Neck stiffness Papilloedema Focal neurological deficit
What investigations are done for subarachnoid haemorrhage?
CT scan (may be normal or show blood) LP if CT inconclusive and 12h post-onset - typically bloody (xanthochromatic) CSF
Outline treatment of subarachnoid haemorrhage
Refer to neurosurgery
Bed rest, support, hydration - aim for systolic BP 160
Nimodipine to reduce vasospasm and ischaemia
Surgery - endovascular coil, clipping, stent, balloon remodelling
What are some complications of subarachnoid haemorrhage?
Rebleeding
Ischaemia
Hydrocephalus
Hyponatraemia
What are the two main intracranial venous thromboses that occur?
Deep vein sinus thrombosis (usually sagittal sinus)
Cortical vein sinus thrombosis
List some aetiology/risk factors for intracranial venous thrombosis?
Pregnancy Oral contraceptive Head injury Dehydration Malignancy Recent lumbar puncture Hyperthyroidism Nephrosis Infection Autoimmunity Tranexamic acid, infliximab
List clinical features of intracranial venous thrombosis
Worsens gradually over days Headache Vomit Seizure Focal neurological signs
What investigations are done for intracranial venous thrombosis?
CT/MRI sinuses
Exclude SAH and meningitis
LP if high opening pressure
Outline treatment of intracranial venous thrombosis
Heparin
Streptokinase via catheterisation
Where does bleeding come from in a subdural haemorrhage?
Bleed from bridging veins between cortex and venous sinuses, causing haematoma between dura and arachnoid
List some aetiology of subdural haemorrhage
Deceleration injury Trauma, often forgotten about Reduced ICP Tumour mets Falls Anticoagulation
List clinical features of subdural haemorrhage
Fluctuating consciousness Insidious intellectual slowing Sleepiness Headache Personality change Focal neurological deficit
What does CT/MRI of subdural haemorrhage show?
Midline shift
Crescent-shaped haematoma
How is subdural haemorrhage treated?
Monitor if small
Irrigate/evacuate via burrhole craniosotomy
Craniotomy if organised clot
Where does the bleeding occur in an extradural haemorrhage?
Bleed due to laceration of middle meningeal artery, causing haematoma between dura and bone
List some aetiology of extradural haemorrhage
Head injury
Trauma to temple lateral to eye
List clinical features of extradural haemorrhage
Initial lucid interval with no LOC Progressive decrease in GCS Headache Vomit Confusion Fits UMN signs Pupil dilation Comatose Limb weakness Abnormal breathing
What does CT/MRI show in an extradural haemorrhage?
Lens-shaped haematoma
Fracture lines
How is an extradural haemorrhage treated?
Clot evacuation + ligation of vessel
Mannitol to reduce ICP
LP is recommended in extradural haemorrhage. True/False?
False
LP is contraindicated
List some aetiology of space-occupying lesions
Tumour (usually mets from breast, lung, skin) Aneurysm Abscess Chronic haematoma Granuloma
List clinical features of space-occupying lesions
Headache, worse on waking/lying down/bending Papilloedema Vomiting Low GCS Seizures Focal neurology (esp VI) Personality change
What investigations would you order for suspected space-occupying lesion?
CT, MRI
Avoid LP! (coning)
Outline treatment for space-occupying lesions
Debulking surgery or excision (N.B. rarely accessible) Carmustine wafers VP shunt Chemoradiotherapy Treat headache and seizures Dexametasone to reduce oedema
Who is particularly at risk of idiopathic intracranial hypertension?
Obese women
List clinical features of idiopathic intracranial hypertension
Blurred vision, diplopia, VI palsy
Enlarged blind spot
Preserved consciousness and cognition
Outline treatment for idiopathic intracranial hypertension
Weight loss Acetazolamide Loop diuretic Prednisolone Consider optic nerve sheath fenestration or lumbar-peritoneal shunt
What is a seizure?
Abnormal spontaneous electrical activity in the brain
What is epilepsy?
Tendency to have recurrent seizures
What are the two types of seizure?
Focal: electrical activity in one part of cortex
Generalised: electrical activity involving both hemispheres
What is the difference between simple and complex seizures?
Simple - no impairment of awareness/consciousness
Complex - impaired awareness/consciousness
List some aetiology of epilepsy
Genetics Developmental/structural abnormality Trauma Inflammation Alcohol withdrawal Space-occupying lesion Tuberous sclerosis SLE Drugs (antibiotics, opioids)
Give examples of aura that may precede a seizure
Strange feeling/sensations
Deja vu
Altered smell/taste
Seeing lights
How does a Jacksonian seizure present?
Simple seizure involving unilateral jerk in one body part
What is the most common complex focal seizure?
Temporal lobe epilepsy involving loss of awareness/deja vu
List the main generalised seizures
Absence (petit mal)
Tonic-clonic (grand mal)
Atonic
Myoclonic
What investigations would you order for epilepsy?
ECG in everyone Bloods, toxicology CT/MRI Lumbar puncture EEG if unsure
What is the treatment for focal epilepsy?
Carbamazepine
Lamotrigine 2nd line
What is the treatment for generalised epilepsy?
Sodium valproate
Ethosuximide 2nd line/absence seizures
Lamotrigine can also be used
What is the pathophysiology of benign paroxysmal positional vertigo (BPPV)?
Debris/otoliths in semicircular canals are disturbed by head movement, causing dizziness
List some aetiology of BPPV
Idiopathic Middle ear disease Head injury Otosclerosis Viral illness