Neuroscience Flashcards
TIA
- investigations
- initial management
- secondary prevention
Investigations: CT scan of head no contrast
Initial management:
give aspirin 300mg
2nd line: clopidogrel 300mg oral
Refer for specialist assessment within 24h
Secondary:
dual antiplatelt therapy
aspirin + clopidogrel for 21 days
or
aspirin + ticagrelor for 30 days
Long-term: clopidogrel 75mg & statin
Stroke
- investigations
- management
Investigations:
CT head without contrast to confirm ischaemic stroke
Management:
Aspirin 300mg immediately
Thrombolysis within 4.5h with alteplase if not contraindicated
dual antiplatelt therapy
aspirin + clopidogrel for 21 days
or
aspirin + ticagrelor for 30 days
If thrombolysis is contra you carry out a mechanical thrombectomy
Subarachnoid haemorrhage
- causes
- symptoms
- investigations
- management
Causes: trauma, berry aneurysm, AVN
Sx: thunderclap headache and meningism
Investigations:
- non-contrast CT head, showing hyperdense blood in the cisterns in a ‘starfish’ appearance
- if CT negative can do a LP 12h after onset to show xanthochromia
Mx:
surgical - endovascular coiling or clipping
medical - nimodipine to prevent vasospasm for 2-3 weeks
Extradural haemorrhage
- place of damage
- Sx
- investigation
- Mx
Damages the middle meningeal artery
Sx - loss of consciousness followed by head trauma (&skull fracture) followed by lucid interval
Investigation - non-contrast CT head
Mx:
ABCDE; oxygen if required
* Urgent neurosurgical opinion
* Manage raised intracranial pressure (ICP)
* Raise head of bed to 30°.
* Analgesia and sedation
* Hypertonic saline or mannitol
* Intubate and hyperventilate
* Definitive management includes craniotomy and haematoma evacuation.
Subdural haemorrhage
- place of damage
- Sx
- investigation
- Mx
Damage to bridging veins
Sx:
acute - similar to EDH
chronic - insidious onset of headache nausea and vomiting
Investigation - non-contrast CT head
Mx:
ABCDE; oxygen if required
* Urgent neurosurgical opinion
* Manage raised intracranial pressure (ICP)
* Raise head of bed to 30°.
* Analgesia and sedation
* Hypertonic saline or mannitol
* Intubate and hyperventilate
* Definitive management includes craniotomy and haematoma evacuation.
Intracranial venous thrombosis
- pathophysiology
- risks
- presentation
- investigation
- Mx
Pathophysiology - clot formation in the cerebral veins or dural venous sinuses and is rare cause of stroke. Cavernus sinus thrombosis is normally due to infection.
Risk - hypercoagulable states
Sx: headache sudden onset, nausea & vomiting, reduced consciousness, papilloedema
Investigation: CT head, CT/MRI venogram, D-dimer, thrombophilia screen
Mx: anticoagulation LMWH followed by long-term warfarin.
Dementia
- types
- presentation
- medical management
- Alzheimer’s disease (AD)
- Vascular dementia (VD)
- Dementia with Lewy bodies (DLB)
- Frontotemporal dementia (FTD)
Presentation
VD - stepwise deterioration
DLB - visual hallucination, REM sleep disorder, Parkinsonism
FTD - personality change and behavioural disturbance
Medical Mx
Alzheimers:
- AChE inhibitors e.g. donepezil, galantamine, and rivastigmine are first line in mild to moderate disease.
- Memantine can be added (NMDA antagonist)
- VD: optimise risk factors
- DLB: same as Alzheimers but antipsychotics and dopamine replacement
- FTD: N/A
Epilepsy
- management
Focal—Lamotrigine or carbamazepine
Tonic-clonic: sodium valproate* or lamotrigine
Absence: ethosuximide or sodium valproate*
Parkinsons
- Sx
- Mx
Symptoms:
- bradykinesia
- resting tremor (4-6hz)
- rigidity (lead pipe or cogwheel)
Mx:
* First-line treatment includes levodopa (combined with carbidopa) for significant functional impairment
* Dopamine agonists (ropinirole)
* MAO-B inhibitors (selegiline)
* COMT inhibitors (entacapone)
Parkinsons + syndromes
Types
Causes
Presentation
Mx
Multiple system atrophy - cerebellar and pyramidal signs
Progressive supra nuclear palsy - vertical gaze palsy and postural instability in the absence of tremor
Corticobasal degeneration
Dementia with Lewy bodies
Sx: fatigue, depression, sleep disturbance, and loss of smell are also common, as well as autonomic dysfunction
Mx: symptomatic
What cranial nerve is damaged in Bells palsy?
Is it UMN or LMN?
CN VII
Unilateral LMN
Myasthenia gravis
Sx
Investigation
Mx
Myasthenic crisis
Sx:
fatiguable muscles through the day
extra ocular muscles affected = diplopia
fatiguable chewing, dysphagia and dysarthria
Investigations
Acetylcholine receptor antibodies (AChR-Ab)
Anti-muscle specific kinase (anti-MuSK) antibodies
CT chest to detect thymic hyperplasia or thymoma
Mx: pyridostigmine
also prednisolone or azathioprine, thymectomy, and monoclonal antibodies such as eculizumab and rituximab
Myasthenic crisis:
* Myasthenic crisis is an acute life-threatening worsening of respiratory muscle weakness that may require ventilatory support.
* It can be triggered by infection, surgery, or certain medications.
* Management consists of intravenous immunoglobulins (IVIGs) or plasmapheresis (plasma exchange).
Guillain-Barré syndrome
Sx
Investigations
Mx
Miller-Fisher syndrome
Sx - progressive weakness affecting lower limbs first, deep tendon reflexes absent, loss of sensation, respiratory muscle involvement
Investigation
LP (raised protein)
Electrophysiology (reduced conduction velocity)
Spirometry
Mx:
IVIG
Thromboprophylaxis (LMWH, stockings)
Intubation and ventilation
Miller–Fisher syndrome is a variant of GBS that presents with a triad of ataxia, areflexia, and ophthalmoplegia. It is associated with anti-GQ1b antibodies.
Neurofibromatosis 1 and 2
Sx of each
Mx
NF1:
* Café-au-lait spots (oval-shaped brown macules)
* Neurofibromas
* Axillary or inguinal freckles
* Optic pathway glioma
* Lisch nodules (iris hamartomas)
* Mild learning difficulties and autism are common
* Seizures
* Skeletal deformities (e.g., sphenoid wing dysplasia, bowing of the tibia and scoliosis)
* Phaeochromocytoma and gastrointestinal tumours
* Renal artery stenosis and hypertension
NF2:
* Early-onset bilateral acoustic neuromas, also called vestibular schwannomas, present with progressive sensorineural hearing loss, tinnitus, and vertigo.
* Other intracranial tumours include meningiomas and ependymomas.
* Cutaneous schwannomas
* Juvenile cataracts
Mx: no curative treatment.
Herpes Simplex Encephalitis
- where does it effect?
- symptoms
- cause
- investigations
- treatment
Temporal lobes
Sx:
fever, headache, psychiatric symptoms, seizures, vomiting
focal features e.g. aphasia
peripheral lesions (e.g. cold sores) have no relation to the presence of HSV encephalitis
Caused by HSV-1 (95%)
Investigations:
CSF: lymphocytosis, elevated protein
PCR for HSV
CT: medial temporal and inferior frontal changes (e.g. petechial haemorrhages) - normal in one-third of patients
MRI is better
EEG pattern: lateralised periodic discharges at 2 Hz
Mx: IV aciclovir
Anterior cerebral artery lesion effects
Middle cerebral artery lesion effects
Posterior cerebral artery lesion effects
Anterior:
- Same side hemiparesis and sensory loss
- In the lower extremity more than upper
Middle:
- Same side hemiparesis and sensory loss
- In the upper extremity more than lower
- Same side homonymous hemianopia
- Aphasia
Posterior:
- Same side homonymous hemianopia with macular sparing
- Visual agnosia (can’t recognise faces)
Webers syndrome lesions
- Opposite CNIII palsy
- Same side weakness of upper and lower extremity
Posterior inferior cerebellar artery lesion
Anterior inferior cerebellar artery lesion
Posterior: laterally medullary, wallenberg
- opposite facial pain and temp loss
- same side limb and torso pain and temperature loss
- ataxia, nystagmus
Anterior: lateral pontine
- Symptoms are similar to Wallenberg’s (see above), but:
- Ipsilateral: facial paralysis and deafness
Common peroneal nerve lesion
Foot drop
Weakness of foot dorsiflexion
Weakness of foot eversion
Weakness of extensor hallucis longus
Sensory loss over the dorsum of the foot and the lower lateral part of the leg
Wasting of the anterior tibial and peroneal muscles
Radial nerve palsy
‘Saturday night palsy’
Can’t extent writst
Numbness over the dorsal aspect of the right hand between thumb and index finger
