Neuro Flashcards
Causes of TIA
Cardioembolism from valve disease, prosthetic valve, post-MI, AF etc
Hyperviscosity e.g. polycythaemia, sickle cell anaemia, VERY HIGH WBC, myeloma
Artherothromboembolism
ALSO, hypoperfusion (important to think abt in young people)
e.g. cardiac dysrhythmia, postural hypotension
Define a TIA
Acute loss of cerebral/ocular function lasting < 24 hours
Complete clinical recovery
RF TIA
Same as IHD
M > F
Black ethnicity have ↑ risk (bc ↑ risk of HTN, atherosclerosis etc)
Age
HTN, Smoking, Heart disease
Peripheral arterial disease
ALSO, combined oral contraceptive pill (bc ↑ risk of clots)
Key presentation of TIA
Sudden loss of function with complete recovery
FAST
What part of the circulation is more commonly affected?
Anterior circulation (90%) - carotid artery
Describe some signs/symptoms if the anterior circulation (carotid artery) is occluded in TIA
Weak, numb contralateral leg and/or similar but milder arm symptoms
Hemiparesis
Hemi-sensory disturbance
Amaurosis Fugax
Dysphasia
Describe some signs/symptoms if the posterior circulation (vertebrobasilar artery) is occluded in TIA
Diplopia, vertigo
Vomiting
Choking and dysarthria
Ataxia
Hemi-sensory loss
Tetraparesis
WHat do oligodendrocytes do?
Myelinate axons in brain (CNS)
What do Schwann cells do?
Myelinate axons in the rest of the body (PNS)
What does white matter contain?
Myelinated axons
What does grey matter contain?
Cell bodies, no myelin sheaths
What are afferents?
Axons which take info towards CNS
What are efferents?
Axons which take info from CNS to rest of body
Function of frontal lobe
Voluntary movement on opposite side of body
Frontal lobe of dom hemisphere controls speech (Broca’s!) and writing
Also, intellectual function, thinking, reasoning and memory
Function of parietal lobe
Receives/interprets sensations
e.g. pain, touch, pressure, body-part awareness (proprioception)
Temporal lobe function
Understanding the spoken word (Wernicke’s), and sounds, memory and emotions
Occipital lobe function
Understanding visual images and meaning of written words
What is CSF produced by?
Mostly by ependymal cells in the choroid plexuses of lateral ventricles
DDx
Hypoglycaemia!!
Intracranial lesion
Migrainous aura
1st line Ix TIA
ROSIER scale - in emergency department
Describe the ROSIER scale
ABCD2 score - risk score of strokes (max = 7)]
A - Age ≥ 60 (1)
B - Blood pressure (at presentation), 140/90 or more (1)
C - Clinical features
Unilateral weakness (2)
Speech disturbance without weakness (1)
D - Duration, 60 mins or longer (2), 10 - 59 mins (1) D - Presence of diabetes (1)
—-
High risk :
- ABCD2 score of 4 or more
- AF
- More than TIA in one week
- TIA whilst on anti-coagulation
Low risk :
- None of the above
- Present more than a week after their last symptoms have resolved
Describe the signs/symptoms if the Anterior cerebral artery (ACA) is occluded in stroke
DCLIT
Drowsiness
Contralateral leg weakness and sensory loss (more leg than arm bc ACA)
Logical thinking and personality affected
Incontinence
Truncal/gait ataxia
Describe the signs/symptoms if the middle cerebral artery (MCA) is occluded in stroke
Contralateral motor weakness/sensory loss (BOTH arms and legs)
Hemiplegia
Aphasia - Wernicke’s and Broca’s
Facial droop
Describe the signs/symptoms if the posterior cerebral artery (PCA) is occluded in stroke
Contralateral homonymous hemianopia
Disorders of perception
Describe the signs/symptoms if the posterior circulation (vertobrobasilar artery) is occluded in stroke
(More catastrophic bc wider region supplied)
Balance and coordination impaired
Describe the signs/symptoms if there is a brainstem infarction
Sudden vomiting, vertigo, ipsilateral Horner’s syndrome
Ix Ischaemic Stroke
URGENT non-enhanced CT head!!! (BEFORE Tx)
to differentiate between ischaemic and haemorrhagic
–
Diffusion weighted MRI - more sensitive, confirms diagnosis
Bloods - to check BG and for polycythaemia etc
Pulse, BP and ECG - check for AF
ESR - vasculitis
U&Es - cholesterol
INR - if on warfarin
Tx Ischaemic stroke
Immediate loading dose of aspirin and refer to specialist !!
Tx Ischaemic stroke
Immediate loading dose (300mg) of aspirin and refer to specialist !!
Continue aspirin for 2 weeks
THROMBOLYSIS WITH IV ALTEPLASE
WITHIN 4.5 hours of symptom onset
Thrombectomy
Within 6 hours of symptom onset
Also : maximise reversible ischaemic tissue
w/ hydration, keep O2 sats > 95%
Contraindications of thrombolysis w/ IV alteplase
Hx of stroke in diabetes patients
Severe stroke
Stroke in last 3 months
Active malignancy
When is thrombectomy indicated?
In severe stroke if large artery affected
Long term management for Ischaemic stroke
SALT support
Rehab
After 2 weeks of aspirin, switch to 75mg Clopidogrel
What is a lacunar infarct?
Small perforating artery occlusion
Supplies subcortical area
(i.e. internal capsule, basal ganglia, thalamus, pons)
Why do you have to be careful about treating BP with an ischaemic stroke?
bc even 20% fall will compromise cerebral perfusion
Hx of SAH
Hx of trauma
Skull fracture
Lucid interval, follows by unconciousness
What is Cushing’s triad?
Bradycardia
Wide pulse pressure
Irregular respirations
What is an intracerebral haemorrhage?
Sudden bleeding into brain tissue due to rupture of blood vessels
∴ infarction bc O2 deprivation
Cause of intracerebral haemorrhage
Uncontrolled HTN is almost always cause
2° to ischaemic stroke - bleeding after reperfusion
Head trauma
AV malformation
Vasculitis
Brain tumour
Cerebral amyloid angiopathy - amyloid beta deposits in small/medium vessles
Carotid artery dissection
RF Intracerebral haemorrhage
HTN
Age
Smoking
Alcohol
DM
Anticoagulation/Thrombolysis
How does HTN cause intracerebral haemorrhage?
Causes stiff, brittle vessels
Prone to rupture, microaneurysms
Key presentation of intracerebral haemorrhage
Same as ischaemic stroke
BUT more likely to lose consciousness or sudden headache
Tx intracerebral haemorrhage
STOP anticoagulants immediately!
Reverse with clotting factor replacement if needed (Beriplex and vit K if on warfarin)
Control BP -
rapid BP lowering if < 6 hours before onset + systolic BP is between 150-220 mmHg
AIM : below 140 mmHg
Reduce ICP
IV mannitol
Mechanical ventilation if needed
Neurosurgical - Decompression/shunting may be req
When might be lowering BP be contraindicated when treating intracerebral haemorrhage?
Underlying structural cause
GCS below 6
Early neurosurgery
Poor prognosis
Prognosis of SAH
High mortality! ~ 50% die straight away
High chance of rebleeding
Most survivors left with severe disability
What are some signs of ↑ ICP?
N+V
Seizures
↑ BP
If a Px has meningococcal disease, what must you do?
Notify Public Health England !!!!!!!!!!
What is supratentorial herniation?
When the cerebrum is pushed against the skull or tentorium
What is infratentorial herniation?
When the cerebellum is pushed against the brainstem
If someone has a skull fracture, what must you do? Why?
Urgent CT
To check if there’s an extradural haemorrhage
What is an extradural haemorrhage also known as?
Epidural haemorrhage
Cause of extradural haemorrhage
Traumatic head injury - usually to temple, usually at pterion
Ruptures middle meningeal artery
With a subdural haemorrhage, focal neurology signs/symptoms occurs when?
Mean = ~ 63 days after injury
Can be days, weeks or months
What is meningitis?
Inflammation of the 2 inner layers of meninges - the leptomeninges (pia mater + arachnoid mater)
What age does meningitis most commonly occur?
Can occur at any age but mostly in infants, young children and elderly
Causes of meningitis
Adults and children :
Neisseria meningitidis
Streptococcus Pneumoniae
(H. Inuenzae - less common now bc vaccine)
Pregnant women/elderly :
Listeria monocytogenes
Neonates :
Escheria coli
Group B haemolytic streptococcus (agalactiae and pyogenes)
Immunocompromised :
CMV
Cryptococcus neoformans (fungi)
TB - mycobacterium tuberculosis
HIV
Herpes simplex virus
Why are pregnant women told to avoid cheese?
Listeria monocytogenes is found in cheese
Risk to pregnant women
If Neisseria meningitidis is in the blood with meningitis, what happens?
Meningococcal septicaemia - endotoxin in blood leads to inflammatory cascade
Non-blanching purpuric rash/petechial rash, necrosis, signs of meningitis
High mortality
Key presentation meningitis
Fever
Headache
Neck stiffness
!!!!!!!
How to test whether a rash if blanching or non-blanching
Glass test
Describe viral meningitis
Benign, self-limiting lasting ~ 4-10days usually
Describe the pathophysiology behind papilloedema
Swelling of the optic disc on fundoscopy
Usually bilateral
Ix meningitis
Immediately assess GCS and take blood cultures - dont wait for results to start treating!!
If in community, give IM benzylpenicillin
Lumbar puncture
Tx meningitis
1. Broad spectrum Abx -
cefotaxime OR ceftriaxone
If immunonocompromised, ↑ Listeria risk
∴ add high dose of amoxicillin
Other stuff
If severe penicillin allergy, then = chloramphenicol
If recent travel, then = IV vancomycin
If viral (enterovirus) = nothing
If viral (HSV or vZv) = acylovir
Prophylaxis! If in contact w meningitis Px for 7+ days (i.e. living together) = one-off dose of ciprofloxacin or rifampicin asap
rifampicin - CI if pregnant
Corticosteroids
Oral dexamethasone to ↓ cerebral oedema and complications (e.g. hearing loss)
4x daily for 4 days to children over 3 months
Describe the findings of CSF in a meningitis patient
Bacteria - turbid colour!
Cells - polymorphs (neutrophils)
Protein = ↑
Glucose = ↓
Virus - clear
Cells - lymphocytes
Protein = ↑ but not as high
Glucose = normal
TB - fibrin web
Cells - lymphocytes
Protein = ↑
Glucose = ↓ or normal
Cryptococcal - fibrin web
High opening pressure!
RF bacterial meningitis
Students
Travel
Immunosuppressed
RF viral meningitis
Small children
Immunosuppressed
RF TB meningitis
TB contact
Immunosuppressed
RF Cryptococcal meningitis
HIV
Immunosuppressed
Should you give penicillin to a meningitis patient with a penicillin allergy?
Yes unless it’s anaphylaxis or severe!
If it’s just a rash or something, not that deep
Meningitis is the bigger threat
Complications of meningitis
Hearing loss
Seizures/epilepsy
Cognitive disability
Memory loss
Focal neurological deficits
How do neonates/children present with meningitis?
Hypotonia
Poor feeding
Lethargy
Hypothermia
Bulging fontanelle
Why do children/neonates have a low threshold for lumbar punctures? Describe these thresholds
Because meningitis presents w non-specific symptoms
< 1 month old with fever
1 - 3 months with fever and are unwell
< 1 year w/ unexplained fever and other features of serious illness
In patients who present with meningitis, what are some indications that you should perform a CT BEFORE a lumbar puncture?
> 60 years
Immunocompromised
History of CNS disease
New onset/recent seizures
Losing consciousness
Papilloedema
Bacterial Meningitis - If severe anaphylaxis w penicillin, what can you give instead?
IV Chloramphenicol
What is encephalitis?
Infection and inflammation of brain parenchyma
Encephalitis viral causes
Viral is most common!
**HSV
VZV, EBV, CMV, HIV, measles, mumps, arbovirus (in West Nile)
Encephalitis Non-viral causes
Bacteria - TB, mycoplasma, rickettsia, listeria, neisserria
Fungal - Cryptococcus, histoplasmosis
Parasitic - malaria, toxoplasmosis, schistosomiasis
Non-Infectious causes of Encephalitis
Paraneoplastic
Post-infectious
Autoimmune
Key presentation Encephalitis
Hours - days before = flu-like illness
then TRIAD of :
1. Altered GCS
2. Fever
3. Headache
Other signs/symptoms of encephalitis
Seizures
Memory loss
Behavioural changes (common early on)
with/without Hx of meningitis (bc it can progress to encephalitis)
Ix Encephalitis
MRI head - shows swelling/inflammation
with/without midline shifting
ECG - periodic sharp and slow waves
Lumbar puncture (after) - ↑ lymphocytes in CSF, viral PCR
May be normal for first 48 hours
DDx encephalitis
Anything that causes behavioural changes -
DKA
Hypoglycaemia
Hepatic encephalopathy
Thiamine deficiency
Meningitis
Stroke
Drug overdose
Brain tumour
What is thiamine deficiency also known as?
Beri-beri
In encephalitis, what does HSV typically affect?
Temporal lobes of brain
Tx Encephalitis
If suspected, start IV Acyclovir until results
If HSV or ZVZ - immediate IV Acyclovir
VZV - can use Ganciclovir
Immunocomp patients - use combination antiviral therapy
For seizures - anticonvulsants e.g. Primidone, Carbamazepine
Complications of encephalitis
Permanent neurological deficits
e.g. epilepsy, movement disorder, personality change, cognitive impairment
Prognosis of encephalitis
Mortality = 10-30% even w/ optimum treatment
Define seizure
Spontaneous, intermittent, uncontrolled electrical brain activity
Define Epilepsy
Recurrent tendency to have seizures, chronic disorder (minimum = 2)
Define prodrome
Non-specific symptoms that precede an epileptic attack
Describe aura
Sensory disturbance that precedes an attack, usually be minutes. More specific
Cause Shingles
Reactivation of varicella zoster virus (chickenpox), usually within dorsal root ganglia
Patient has chicken pox, then virus is latent in dorsal root ganglia
What age do shingles present?
Any age but usually elderly
Route of transmission Shingles
CANNOT be caught from contact w person w chickenpox
Patients with rash are infectious until lesions dry
RF Shingles
↑ Age
Immunocomp
HIV
Hodgkin’s lymphoma
BM transplant
Low Vit D
Presentation Shingles
Pain and paraesthesia in area (side of face or body) then rash. Restricted to same dermatome
Also : malaise, myalgia, headache, fever
Tx Shingles
Oral antivirals within 72 hours of rash onset
e.g. Oral aciclovir x5 daily
OR oral valicilovir x2 daily OR oral famciclovir x2 daily
+ Analgesia for pain
Shingles complications
Damage to opthalmic branch of trigeminal nerve - affect sight!
Post herpetic neuralgia - pain for more than 4 months AFTER shingles
How do you treat post herpetic neuralgia?
Tricyclic antidepressant e.g. oral amitriptyline
Anti-epileptic e.g. oral gabapentin
Anti-convulsant e.g. oral carbamazapine
Define Multiple Sclerosis
Chronic autoimmune disease.
T-cell mediated inflammatory disease of CNS, multiple plaques of demyelination within brain and spinal cord
EPISODES MUST BE DISSEMINATED BY TIME AND SPACE
How is MS classified?
Pattern 1 - macrophage mediated
Pattern 2 - antibody mediated. lots of inflammation
Pattern 3 - distal oligodendrogliopathy (virus induced)
Pattern 4 - 1º oligodendroglia degeneration (metabolic defect)
RF MS
FEMALE ! (2:1 F:M)
20 - 40 years
More common the further from equator
More common in caucasian
HLA-DR2
Exposure to EBV early in childhood
Age of migration
Types of MS progression
Relapsing/Remitting MS - most common
1º progressive
2º progressive
Progressive/relapsing (sucky)
Draw graph!!
Describe relapsing-remitting MS progression
Clearly defined relapses w/ full or partial recovery and residual deficits!
Between bouts, no progression in disability
Describe 1º progression of MS
Disease progresses continuously
Maybe plateaus and minor improvements but no relapses/remission
Describe 2ºprogression of MS
Initially relapsing-remitting then progresses continuously
Describe progressive-remitting progression of MS
Progressive disease w/ clear acute relapses. Periods between relapses are still progressive
What type of hypersensitivity reaction is MS?
Type 4 (cell-mediated)
What is Charcot’s triad?
Intention tremor
Nystagmus
Dysarthria (Scanning/staccato speech)
What’s Lhermitte’s sign?
When bend neck down, electrical shock runs down back and to limbs
Key presentation of MS
Charcot’s triad
Lhermitte’s sign
What is MS exacerbated by?
HEAT! e.g. showers, hot weather, sauna
Uhthoff’s phenomenon
Other signs/symptoms of MS
LOSS NB
Lhermitte’s sign
Optic neuritis
Spasticity
Sensory symptoms/signs
Nystagmus, double vision and vertigo
Bladder and sexual dysfunction
What visual signs/symptoms does MS cause?
Optic neuritis - loss of colour discrmination
Internuclear ophthalmoplegia!
Relative afferent pupillary defect (RAPD)
Ix MS
MRI WITH CONTRAST - active lesions white, in the periventricular regions
Lumbar puncture w/ CSF electrophoresis - oligoclonal IgG bands = CNS inflammation (sensitive, not specific), ↑ lymphocytes
Other : Aevoked potentials - tests how long impulses take to travel, longer w demyelination
What cells are targeted in MS?
OLIGODENDROCYTES ! - CNS
Not Schwann cells
What specific CNS sites are targeted in MS?
Perivenular, everywhere in CNS but especially :
Optic nerves
Around ventricles of brain
Corpus callosum
Brainstem and cerebellar connections
Cervical cord
How does unilateral optic neuritis present?
Pain in one eye upon eye movement
Reduced central vision
Tx Acute attacks of MS
e.g. relapsing-remitting
Corticosteroids - IV methylprednisolone (1g od for 3 days)
Tx Chronic MS
i.e. frequent relapse
1st :
SC beta interferon and glatiramer acetate
2nd :
IV alemtuzumab or IV natalizumab
S/E of Beta-Interferon
Flu-like symptoms
Mild intermittent lymphopenia
Mild-moderate rise in liver enzymes
Pathophysiology of IV alemtuzab
CD52 monoclonal antibody, targets T cells
Pathophysiology of IV natalizumab
Reduces immune cells that can cross BBB
Tx for symptom management of MS
Tremors - beta blockers
Muscle spasticity - baclofen, gabapentin
General - removal of triggers, physio
What do ALL anti-spasticity medications cause?
Weakness
Pathophysiology of Baclofen
GABA analogue, reduces Ca2+ influx
∴ surpasses release of excitatory neurotransmitters
Prognosis of MS
5-10 years below average
Often die from aspiration pneumonia due to dysphagia
Define Guillain-Barre syndrome
Acute, inflammatory, demyelinating polyneuropathy
Progressive, ascending loss of sensation
What age does Guillain-Barre syndrome present in?
2 peaks
15-35 years and 50-75 years
Cause of Guillain-Barre syndrome
Usually preceded by resp/GI infection 1-3 weeks before
Bacterial : Campylobacter jejuni, Mycoplasma pneumoniae
Viral : CMV, EBV, ZVZ, HIV
RF
Hx of resp/GI infections a couple weeks before
Vaccinations might be implicated !
Post-pregnancy has higher risk (during pregnancy tho has lower incidence)
Types of Guillain-Barre syndrome
Demyelinating
Axonal
Axonal sensorimotor
Miller Fisher syndrome - very rare
What does Miller Fisher syndrome affect?
Cranial nerves to eye muscles
Key presentation of Guillain-Barre syndrome
- Symmetric, ascending limb weakness
- Reduced/absent tendon reflexes
- Reduced sensation
What cells are affected in Guillain-Barre syndrome?
Schwann cells!
Condition of the PNS
Other signs/symptoms of Guillain-Barre syndrome
Cranial nerves - diplopia, dysarthria
Resp - affects diaphragm (death)
Reflexes are lost early on !!!
Back/limb pain
Autonomic features - sweating, ↑ pulse, postural hypotension
Ix Guillain-Barre syndrome
Electromyography (EMG)
Nerve conduction studies - slow conduction
LP (done at L4) - CSF = ↑ protein but normal WBC!
also : can check lung function w/ spirometry
Tx Guillain-Barre syndrome
IV immunoglobulins
Plasmapheresis
When using IVIG to treat Guillain-Barre syndrome, what does it do?
Decreases duration and severity of paralysis
When is IVIG contraindicated?
If IgE deficient
bc can cause severe allergic reaction
When using plasmapheresis to treat Guillain-Barre syndrome, what does it do?
Eliminates harmful antibodies
How can you reduce venous thrombosis in Guillain-Barre syndrome?
LMWH e.g. SC enoxaparin
+ compression stockings
Prognosis of Guillain-Barre syndrome
Disease progresses for 2 weeks then plateaus for 2-4 weeks
then recovery! takes several months to regrow myelin sheath
What is the peak age of onset with Parkinson’s?
55 - 65 years
But can be diagnosed early (40)
What happens in Parkinson’s disease?
Degeneration of dopamine-producing neurons in substantia nigra
Key presentation of Parkinson’s disease
TRAP
Tremor (resting, pin-rolling)
Rigidity (cogwheel)
Akinesia
Postural instability
NO WEAKNESS
Other signs/symptoms of Parkinson’s disease
Shuffling gait!
Mask-like face
Depression
Autonomic problems - constipation! ↑urinary freq
Other signs/symptoms of Parkinson’s disease
Shuffling gait!
Mask-like face
Depression
Constipation
What medication, used to treat a neurological disease, causes constipation?
Levadopa - Parkinson’s
What can cause foot drop?
What is the difference in presentation with these two causes?
Common peroneal nerve palsy - causes eversion
L5 Radiculopathy - causes inversion
Key presentation of Cauda Equina syndrome
Saddle anaesthesia
Loss of sensation in bladder and rectum - not knowing when full
Urinary retention / incontinence
Faecal incontinence
Bilateral sciatica
Bilateral or severe motor weakness in legs
Reduced anal tone
Causes of Cauda Equina
*Herniated disc
Tumours - mets
Spondylolisthesis
Abscess infection
Trauma
Ix Cauda Equina
Medical emergency!! - immediate neurosurgery for lumbar decompression surgery
Emergency MRI scan to confirm !
Tx Cauda Equina
Surgical decompression ASAP
Immobilise spine
Anti-inflammatory agents
Chemo if mets
Abx if infection
What is Bell’s palsy?
LMN weakness of CN 7 (facial nerve)
Results in peripheral facial palsy
Presentation of Bell’s palsy
Rapid onset (< 72 hours) of unilateral facial weakness
Loss of taste
Post-auricular/ear pain
Difficulty chewing
Drooling
Tingling in cheek/mouth
Ocular dryness
Drooping of eyebrow
Define epilepsy
Recurrent tendency of spontaneous, intermittent, abnormal electrical activity in brain that results in seizures
Name of post-ictal symptoms
Headache
Confusion
Myalgia
Sore tongue
What is Todd’s palsy?
Temporary weakness/paralysis after focal seizure, usually resolves after 2 days
