Phase 2 - Neuro Flashcards
Define meningitis
Inflammation of the pia and arachnoid mater. Oft caused by organisms infecting the CSF.
Define meningism
A set of symptoms indicative of some kind of meningitis, not necessarily of an infective cause (e.g. chemical meningitis/post-surgical)
- Stiffness of neck
- Severe headacje
- Photophobia
Symptoms of infective meningitis
- Pyrexia
- Malaise; N+V
- May have NON-BLANCHING PURPURIC RASH - characteristically HAEMORRHAGIC in meningococcal (n meningitidis) meningitis
- Meningism
- Kernig (can’t extend knee when hip is flexed)
- Brudzinski sign (knee + hip automatically flex when neck flexed while lying down)
Causes of infective meningitis
- 80% - viruses:
- Enteroviruses (Echo virus, Coxsackie virus)
- historically Polio
- Herpes simplex
- Mumps
- Lymphocytic chorio meningitis virus
- Enteroviruses (Echo virus, Coxsackie virus)
Bacterial (notifiable):
- Neonates:
- E coli
- Group B (found in genital tract - 25% at child-bearing age)
- Listeria monocytogenes
- Pinpoint to small, semi transparant colonies with narrow haemolytic zone on Blood Agar
- S pneumoniae
- infants:
- N meningitidis
- Strep pneumoniae
- H influenzae
- a G -ve bacillo-coccus
- fastedious, requires Factors V+X
- Adults:
- Neisseria meningitidis
- Strep pneumoniae
- both are diplococci but Neisseria is G -ve
- Elderly:
- Strep pneu
- N mening
- Listeria monocytogenes
Listeria affects extremes of age, immunocompromised (including pregnant women + DM)
- crowded environment + non-vaccination = RFx
Viral more common, bacterial more severe
Define encephalitis
Inflammation of cerebral cortex
Symps of encephalitis
- Lethargy + fatigue
- decreased level of consiousness
- Fever
- Headache
- Encephalopathy, Focal neurology - esp Temporal lobe -> e.g. aphasia
- occasionally - fits
Combined with meningism = meningo-encephalitis
Causes of encephalitis
Usually viral:
- Herpes simplex - 95%
- Vaicella zoster
- Parvovirus
- HIV
- Measles
- Mumps
Occassionally - toxoplasma gondii from cats
Lab investigations for meningitis/encephalitis
MRI HEAD for Encephalitis (unilateral inflam) - do first to check ICP
CSF obtained via LUMBAR PUNCTURE - ‘gin-clear’, pressure <15cm of H2O (fast - analysed within couple of hours)
- analysed for:
- cell count
- Gram film
- Protein
- Glucose
- Culture on blood/chocolate agar
- PCR - enteroviruses, HSV, VZV, s pneum, n mening
- CONTRAINDICATED in raised ICP due to risk of tentorial herniation/coning
Blood - cultures + PCR for S pneum + N mening
Nose + throat swabs - blood/chocolate agar + PCR for enterovirus
Stool PCR for Enterovirus
CSF lab findings consistent with bacterial infection
- Neutrophil predominant leucocyotosis
- Raised protein (from dying bacteria, acute phase antibacterial proteins + Ab)
- Reduced CSF glucose to serum glucose ratio (Neutrophils + bacteria use up)
Empirical treatment for bacterial meningitis
IV cefotaxime/ceftriaxone (3rd gen cephalosporins)
- broad spectrum against all common CNS bacteria
- good CNS penetration
+ IV DEXAMETHASONE (corticosteroid) adjuvent therapy (ie simultaneously)
- reduce risk of long term neurological complications
- start at same time/immediately prior to starting antibiotics (ie as soon as bacterial diagnosis confirmed)
If Immunocomp give AMOXICILLIN - covers Listeria
If Px presents to GP with non-blanching, purpuric rash -> give IM BENZYLPENICILLIN + immediate hospital referral
Antibiotic therapy for Listeria monocytogenes CSF infection
IV AMOXICILLIN - HIGH DOSE + FREQUENCY
- 2g every 4-6hrs
- start as soon as diagnosed or empirically if suspicion of bacterial meningitis in Immunocomp patient.
May add IV GENTAMICIN as adjunctive Abx
When is a lumbar puncture not required in diagnosing bacterial meningitis
If the patient presents with the carachterisitc haemorrhagic rash + meningism -> strong clinical suspicion of MENINGOCOCCAL SEPTICAEMIA + meningitis
- lumbar puncture is unnecessary + may be harmful if there are any coag abnormalities secondary to meningococcal sepsis
- diagnosis can be confirmed by peripheral blood culture or peripheral blood molecular testing (PCR) for N meningitidis
What actions should be taken if a patient is confirmed to have meningococcal meningitis
- Notify Public Health England
- Close contacts should be offered antibiotic prohphylaxis
- usually single dose of ORAL CIPROFLOXACIN (fluoroquinolone)
CSF lab findings consistent with viral meningitis/encephalitis
- predominantly lymphocytic response
- only moderately raised protein
- CSF glucose is >50% of the level of the paired serum sample glucose
Treatment for encephalitis
IV ACICLOVIR for HSV or VZV
If enterovirus -> self limiting, no antiviral needed just supportive measures where necessary
Define Transient Ischaemic Attack
Sudden onset neurological Deficit that lasts for less than 24hrs, caused by focal brain, spinal cord or retinal ISCHAEMIA WITHOUT EVIDENCE OF ACUTE INFARCTION
- not a medical emergency so doesn’t require immediate hospitalisation
Epidemiology of TIA
- 90% = ICA (anterior)
- 10% vertebral (posterior)
Causes of TIA
CAROTID THROMBO-EMBOLI
- thrombosis
- emboli (fat from atheroma or thrombus, typically from heart) - remember AFib = risk factor for stroke!
RFx for TIA
Almost same as IHD/stroke
- Smoking: Increased Alcohol
- Diabetes T2
- HTN
- AFib
- Obesity/hypercholesterolaemia
- VSD
Also:
- FHx of stroke/TIA
- Age >55
- Higher risk in males
(-genetics may play a factor)
Presentation of TIA
Focal neurology - sudden onset; typically lasts 5-15mins, can last up to 24hrs:
- ACA -> weak/numb contralateral leg
- MCA -> contralateral hemiparesis - esp forehead sparing face drooping
- temporal = receptive dysphasia; frontal = Expressive dysphasia
- Posterior CA -> Contralateral homonymous hemianopia w/ macular sparing (occipital cortex)
- Vertebral A -> Cerebellar syndrome (DANISH - sensory + motor)
- potential Brainstem infarct (loss of basic vital functions)
- Cranial nerve lesions 3-12
- potential Brainstem infarct (loss of basic vital functions)
- AMAUROSIS FUGAX -> occlusion/reduced blood flow to RETINA via OPTHALMIC, RETINAL or CILIARY ARTERY
- BAD PROGNOSIS - oft indicates oncoming STROKE
Dx of TIA
Clinical - same as stroke
- FAST (face, arms, speech, time)
- ABCD2 (no longer advocated by NICE)
- Age >60 (1 point)
- BP >140/90 (1)
- Clinical Sx (unilateral weakness = 2; slurred speech, no weakness = 1)
- Duration (>1hr = 2; <1hr = 1)
- T2DM (1)
- score >6 = urgent referal to nerology, >4 = high risk TIA
Tx of TIA
- Refer to specialist assessment within 24hrs (7 days) of onset
- Start STATIN (simastatin 40mg)
- Acutely = Immediate ASPIRIN/Clopidogrel 300mg
- Treat BP if raised
- Long term prophylaxis = CLOPIDOGREL 75mg (or MR diapyramidole) + ATRVASTATIN 80mg
Don’t drive till seen by specialist
- If High risk need to be assessed within 24hrs
Classification of ischaemic stroke
TOAST classification (subtypes of ischaemic stroke):
- Large vessel disease (atherosclerosis) - (mc - 50%)
- Small vessel disease (occlusion) (25%)
- Cardioembolic (esp AFib -more common in elderly, female) (20%)
- Cryptogenic (no RFx + can’t find cause - undetermined aetiology) (+ rarities = 5%)
- Rarities (other aetiologies not covered by above)
Define iscahemic stroke
Episode of NEUROLOGICAL DYSFUNCTION caused by FOCAL cerebral, spinal or retinal INFARCTION (lasting more than 24 hrs)
Epidemiology of Ischaemic Stroke
- 80-85% of strokes
- 25% of ischaemic strokes in young people (<45 y/o) is caused by DISSECTION
- Better prognosis/outcomes if treated on a dedicated stroke unit vs conventional ward
- 84% return home but few return to work
Causes/RFx of Ischaemic strokes
- Large vessel = atheroma (obesity) -> thromboembolism
- Small vessel = HTN, DIABETES, SMOKING + AGE -> microatheromas
- Cardioembolism
- Mural thrombus, (HF?)
- AFib, Atrial septal defect
- Endocarditis
- Dissection (carotid/vertebral)
- trauma/cervical manipulation (e.g. getting head pulled back at hairdresser’s)
- Vigorous physical activity (e.g. weight lifting)
- Vasculopathy (fibromuscular dysplasia, Marfan’s -> weaker, more likely to tear)
- Causes stenosis/aneurysm of medium-sized arteries -> reduced perfusion/wall can break
- Sympathomimetic drug abuse (e.g. dopamine, NAd, Adr etc.)
- Increased stimulation of sympathetics -> peripheral vasoconstriction + reduced systemic compliance -> increased blood flow/pressure during systole -> more likely to tear
- Rarities
- Vasculitis (string of beads - microaneurysms) - consider renal involvement
- Venous thrombosis (back pressure -> swelling -> blocks blood supply) - oft have thrombophilia (consider in post-partum, infection, dehydration, malig) - shows up as papilloedema
- Haem conditions like SCD or aPL syndrome -> increased coagulability
- Hyperviscosity syndrome e.g. Polycythemia vera
- Idiopathic
Other RFx:
- MALE
- Main = increased AGE (>65), HTN, SMOKING
- Migraine with aura (concurrent sensory disturbance) (esp in younger women) -> causes brain hypoperfusion
- FHx; genetic factors
- Previous TIA (increased risk of stroke in around 10 days after)
- Alcohol
- DM+lipids + cardiac disease
- Carotid bruit (indicates stenosis)
Pathophysiology of ischaemic stroke
Large vessel:
- Atherosclerosis - esp at bifurcations/curvature/confluence (carotid bifurcation, aortic arch + basilar artery respectively) - most common
- Rupture -> thromboembolism further up brain vessel (e.g. MCA - unlikely to have atherosclerosis, much more likely to have embolism)
Small vessel:
- Small, deep perforator/penetrating arteries blocked by the formation of in situ microatheromas or lipohyalinosis (concentric thickening of small cerebral arteries -> narrowing of lumen -> occlusion)
- Looks like small holes/cobweb mesh at post-mortem (lacunae)
- Microatheroma -> weakens vessel
Cardioembolism (blood stasis forming thrombus/pathogenic colonies in heart -> embolism from heart - Oft get big clots)
Dissection - increased strain on vessels - esp CAROTID/VERTEBRAL - or reduced ability of vessels to comply with increased strain -> wall breaks
Presentation of anterior circulation stroke
Anterior circulation (stemming from internal carotid):
- Dominant hemisphere affected (usually left, even in left-handed people)
- Language dysfunction
- Expressive or Receptive dysphasia
- Dyslexia
- Dysgraphia
- Non-dominant hemisphere affected:
- Anosognosia
- Neglect (unaware of paralysed side of body)
- Denial of weakness
- Visuospatial dysfunction
- Dressing/gait apraxia
- Anosognosia
- Either hemisphere ->
- Hemiparesis (one side paralysis)
- Hemisensory loss
- Visual field defect
Presentation of posterior circulation of iscaemic stroke
- Unsteadiness (cerebellar involvement)
- Visual disturbance
- Homonymous hemianopia w/ MACULAR SPARING (occipital lobe)
- Prosopagnosia (can’t regnise faces)
- Slurred speech
- Headache more common than in anterior stroke
- Vomiting (can be mistaken for viral infection - oft leads to late diagnosis)
What specifically does a lacunar stroke affect/present with
It is just a small vessel ischaemic stroke affecting the LENTICULOSTRIATE ARTERIES which supplies deep brain structures
-> ischaemia/infarct of basal ganglia, internal capsule, thalamus, pons
Contralateral hemiparesis + pure motor/sensory loss (or mix of both)
Stroke vs non-stroke
- Stroke usually more abrupt (within secs)
- Strokes usually more focal
- Strokes usually cause loss of function (non-strokes = =ve symps e.g. flashes of light in visual field - migraine)
- Max neurological symptoms at beginning for strokes - for non-strokes can get worse over time
DDx for stroke
- Todd’s paresis - after effect of EPILEPTIC SEIZURE
- Space occupying lesions e.g. tumours
- Infection (esp in elderly) - can cause decompensation in areas previously affected by stroke
- Metabolic disorders - hyper/hyponatraemia, hypoglycaemia, alcohol/drugs (cannabis/cocaine), thyroid dysfunction
- MS (oft in younger) - can have episodes years apart, recover fully inbetween
- Functional neurological disorder (stressful situations - linked to PTSD)
- Migraine
Treatment of ischaemic stroke
Hyperacute:
-
IV Thrombolysis within 4.5 hours of starting stroke - prevents progression -> TISSUE PLASMINOGEN ACTIVATOR or ALTEPLASE (if at risk of bleeding may take aspirin/other anti-platelet)
- Drugs can be administered via catheter to brain
- If proximal M1 (stem of MCA) occlusion (v. large) - thrombolysis only works in ⅓ of cases
-
Mechanical thrombectomy - wire fed up femoral artery in groin -> fed up to brain -> grab clot + pull out
- Needs to be given within 6 hrs (or within 24hrs if sufficient penumbra on CT perfusion);
- works best if they had good function before stroke (e.g. could walk unaided) + had large proximal artery occlusion (internal carotid or proximal M1/M2 segment)
-
Mechanical thrombectomy - wire fed up femoral artery in groin -> fed up to brain -> grab clot + pull out
- Carotid atherosclerosis -> remove surgically within a week (ENDARTERECTOMY)
- Urgent if 50-99% stenosis on symp side
Secondary prevention:
- ANTIPLATELETS - Aspirin 300mg for 2 weeks -> lifelong clopidogrel 75mg
- Warfarin/DOAC if AFib/mural thrombus
- STATINS - reduces risk of future vascular attacks (aim to lower LDL by >40% + keep total cholesterol <3.5)
Lower plasma LDL, inhibit cholesterol synthesis (in liver), stabilise atheromas + are anti-inflammatory - LOWER BP - ACEI, THIAZIDEs, CCBs
Complications of ischaemic stroke
- Ischaemia can cause oedem within next 48hrs
-> Hemicraniectomy (remove part of skull) - but can cause disability
Define Haemorrhagic stroke
2 types:
- Primary Intracerebral: RAPIDLY developing clinical signs of NEUROLOGICAL DYSFUNCTION attributable to a FOCAL COLLECTION OF BLOOD within brain PARENCYMA/VENTRICULAR SYSTEM - not caused by trauma - more acute than ischaemic
- Subarachnoid: RAPIDLY developing NEUROLOGICAL DYSFUNCTION AND/OR HEADACE due to bleeding into subarachnoid space - not caused by trauma
Define haemorrhagic stroke
2 type:
- Primary Intracerebral: RAPIDLY developing clinical signs of NEUROLOGICAL DYSFUNCTION attributable to a FOCAL COLLECTION OF BLOOD within brain PARENCYMA/VENTRICULAR SYSTEM - not caused by trauma - more acute than ischaemic
- Subarachnoid: RAPIDLY developing NEUROLOGICAL DYSFUNCTION AND/OR HEADACE due to bleeding into subarachnoid space - not caused by trauma
Epidemiology of Haemorrhagic strokes
20% of strokes
Causes of haemorrhagic stroke
2 types -> Intracerebral + subarachnoid
- Intracerebral:
-HTN- Amyloidosis
- Arteriovenous malformation
- Aneurysm rupture
- Subarachnoid:
- Aneurysm rupture - esp BERRY ANEURYSM (feels like Thunderclap headache/hit on head by cricket bat)
Presentation of haemorrhagic stroke
- Focal neurological symps
- RAISED INTERCRANIAL PRESSURE -> papilloedema, more generalised symps
- risk of TENTORIAL HERNIATION
- CONING: hernitation of medulla/brainstem through foramen magnum
- oft Midline shift
Treatment of haemorrhagic stroke
- DO NOT GIVE/STOP ANTICOAGS
- Aggressively Reduce BP <150 systolic (e.g. RAMIPRIL)
- unless underlying structural cause, GCS <6, early surgery or poor prognosis
-
Neurosurgery referral
- May clamp broken vessel/use coil to give structural support
- For arteriovenous malformation -> surgical removal; shrink with radiation; chemically block blood flow to malformed are
- IV mannitol for raised ICP
2ndry
- fix clotting
- lower BP <150 systolic
- Statins
Dx of stroke
- 1ST LINE (+ gold for bleeds) = NCCT HEAD (fast, cheap)
- ischaemia looks normal in first few hours; Haemorrhage = HYPERDENSE BLOOD
- Gold = MRI BRAIN with DIFFUSION WEIGHTED IMAGING (for ischaemic) - measures changes in water movement across cell walls to show exact affected area
- Bloods (including vasculitis screen)
- WCC, Plts, Cholesterol/Lipid screen
- PT/aPTT
- ECG +/- 72 hour tape (irregular heart rhythms -> can indicate stroke) - esp in cardioembolic
- Carotid Doppler US - common area of atherosclerosis -> need to remove or can thrombose (need to image within few days of stroke)
- ECHO (for cardioembolic)
- CT/MR angiogram of head + neck - e.g. for dissection or carotid occlusion
What is Romberg test
Determines if your balance issues are related to the function of your dorsal column by removing the visual and vestibular components that contribute to maintaining balance
(need at least 2 of: proprioception, vision, vetibular input - to normally maintain balance)
Just stand still w// eyes closed + arms crossed
- used to identify cerebellar damage
DANISH acronym
- Dysdiadochokinesia
- Ataxia (gait and posture)
- Nystagmus
- Intention tremor
- Slurred, staccato speech
- Hypotonia/heel-shin test
Define subarachnoid haemorrhage
Bleeding into subarachnoid space typically due to BERRY ANEURYSM RUPTURE (circle of Willis - esp at anterior commisure artery junction) or Trauma
RFx for Subarachnoid haemorrhage
- Marfan’s/Ehlers Danlos
- HTN
- POLYCYSTIC KIDNEY DISEASE
- TRAUMA
- Increased age
- FHx
Sx of subarach haem
- SUDDEN ONSET OCCIPITAL THUNDERCLAP HEADACHE (berry aneurysm rupture)
- 50% have SENTINAL HEADACHE (throbbing ocipital pain) preceding for weeks
- 0 -> 10 severity instantly (worst headache ever)
- Meningism (but no meningitis)
- Kernig’s sign - can’t straighten leg when hip flexed to 90 degrees (stiff hamstring)
- Brudzinski’s sign - severe neck stiffnes -> hips + knees flex when neck is flexed/elevated in lying position
- reduced Glasgow Coma Score
- nerve palsy CN 3 + 6 (fixed dilated pupil + raised ICP signs)
DDx subarach haem
- meningitis (no thunder clap headache + has infection)
- migrane (no meningism or thunderclap)
Diagnosis of subarach haemorrhage
- 1st + Gold = NCCT HEAD (diagnostic)
- star shaped white area
- If +ve -> CT angiogram (to see extent of rupture)
- If -ve -> LUMBAR PUNCTURE (but wait around 12 hours as results are most sensitive after 12hrs)
- will see XANTHOCHROMIA after 12hr (CSF = yellowish from RBC haemolysis)
Can get vasospasm or delayed cerebral ischaemia - usually 3-14 days after haemorrhage - indicated by:
- drop of 2 or more GCS
- new focal deficit occuring 3-14 days after; not attributable to other causes
Tx of subarach haemorrhage
- 1st line - cardiopulmonary support if GCS <= 8; >8 = support + monitoring
-
NIMODIPINE (CCB - decreases vasopressin + BP - reduced risk of delayed ischaemia)
- stop/reverse anticoag if needed
- anticonvulsant where needed
- Gold - NEUROSURGERY - endovascular coiling or surgical clipping
- if acute hydrocephalus - ventriculostomy or lumbar drainage of CSF
If vasospasm pr delayed cerebral ischaemia -> refer to neurosurgeon
Define subdural haemorrhage
Rupture of BRIDGING VEIN due to SHEARING
RFx for subdural haemorrhage
- TRAUMA (e.g. DECELERATION injuries)
- Coagulopathy/anticoag use
- AGE >65
- CHILD ABUSE (SHAKEN BABY SYNDROME)
- Cortical atrophy (e.g. dementia, excessive alcohol)
Sx of subdural haem
- GRADUAL ONSET - has a LATENT PERIOD
- small bleeding -> accumulation + AUTOLYSIS of blood
-> Symps after days/weeks/months
- characterised by evidence of trauma, headache, N+V + loss of function
- small bleeding -> accumulation + AUTOLYSIS of blood
- Signs of RAISED ICP
- CUSHING’S TRIAD (bradycardia, irregular respirations, widening pulse pressure)
- Fluctuating GCS
- Papilloedema
Focal neurology later e.g. CN3 palsey
Dx of subdural haem
NCCT HEAD -> CRESENT shaped haematoma, NOT CONFINED to suture lines
- midline shift
- acute = hyperdense
- subacute = isodense
- chronic (or late) = HYPOdense (darker than brain)
Alt MRI/plain skull x-ray
Tx of subdural haem
If <10mm size; midline shift <5mm; no significant neurological dysfunction
- consider prophylactic antiepileptics
- normalise coag profile but STOP ANTICOAG
10mm or more; midline shift >5mm; significant/expansile neurological dysfunction
- SURGERY
- BURR HOLE CRANIOTOMY (make 2 burr holes - irrigate clot with saline + suction)
- Trauma craniotomy (frontotemporoparietal craniotomy, durotomy, removal of clot)
- Hemicraniotomy (oft done when considerable cerebral swelling/intraparenchymal lesions)
Address cause of fall e.g. from arrhythmia or cateracts
If chronic -> give antiepileptics
Give IV MANNITOL to lower ICP
Extradural/epidural haemorrhage
TRAUMA esp to MIDDLE MENINGEAL ARTERY due to damage to pterygoid bone (around ear)
RFx for extradural haemorrhage
- Typically 20-30 y/o - HEAD TRAUMA
- less likely to occur in older as dura more firmly adhered
- v rarely can get extradual contralateral to a subdural bleed - surgery to remove subdural can then allow extradural to rapidly expand if not identified
Presentation of extradural haemorrhage
- Initial event -> Lucid interval - may last hours-days-weeks -> RAPID DETERIORATION due to RAISED ICP
- old blood clots become haemolysed + TAKE UP WATER (osmotically active) -> increase ICP by increasing volume
- Reduced GCS (coma, confusion)
- RAISED ICP (cushing triad, papilloedema)
Dx of extradural haem
- NCCT HEAD -> (LENS shaped) BICONVEX hyperdense bleed - CONFINED TO SUTURE LINES - midline shift
- Alt MRI or Plain skull XR
Tx of extradural haem
- ABCDE
- URGENT SURGERY
- MANNITOL to reduce ICP
Complication of intracranial haemorrhage
BRAINSTEM/TONSILLAR HERNIATION/CONING -> Compressed respiration centres -> resp arrest (-> death)
- due to untreated raised ICP
Issue with codeine in headaches
Oft used for headaches but causes worsening of headache
Types of primary brain tumours
Classified based on cell of origin + area
- GLIOMAS (most common)
- Astrocytoma (astrocytes - maintain homeostasis + neuronal metabolism - 90%
- 2nd mc pediatric cancer overall - Oligodendrocytoma/oligodendroglioma (myelinating cells)
- Ependymoma (ependymal cells lining ventricles)
- Astrocytoma (astrocytes - maintain homeostasis + neuronal metabolism - 90%
- Meningioma
- In sellar region
- e.g. Craniopharyngioma, Pit adenoma
- Germinomas (rare, usually pediatric, cancerous, usually in pit/pineal region)
- Cranial nerves = SCHWANNOMA (e.g. VIII nerve = acoustic neuroma)
- Haematopoetic (primary CNS lymphoma)
Most common cause of brain tumour
SECONDARY METS
- Non-small cell LUNG cancer (main cause) + small cell lung cancer
- BREAST
- Malignant Melanoma
- Renal cell cancer
- Gastric cancer/COLORECTAL
- Testicular
Epidemiology of brain tumours
Increasing incidence
55% malig
9th most common - commonest cause in younger ppl (men <45, women <35)
Only 3% of all cancers
Non germinomatous pineal tumours = 90% male - esp during puberty 10-19 y/o
- Grade 2 gliomas - slow growing but undergo anaplastic transformation:
AVERAGE SURVIVAL = 10 YEARS (astrocytomas worse - 3-5 yrs)- Even if it goes anaplastic - better prognosis than de novo high grade
- Grade 3 gliomas - survival = 3-5 yrs
- Grade 4 - survival = 12 months
Median age affected by diff grades of primary brain tumours
Grade 2 = 35
Grade 3 = 45
Grade 4 = 60
Causes/RFx for primary brain tumours
- Majority idiopathic
- Ionising radiation (esp if in childhood e.g. for leukaemias - esp meningiomas)
- 5% family Hx
-Associated genetic syndromes:- neurofibromatosis type 1 (nerve tumour disease)
- tuberous sclerosis (mostly benign tumours, diff parts of body),
- Hippel-Lindau disease (tumours + cysts - usually benign)
- white males
- Immunosuppression (CNS lymphoma)
Classification system used for brain tumours
WHO classification system
- based on histology, molecular markers + genetic factors
(brain tumours only spread in CNS so no TNM classification - medulloblastomas can drop down spine but still inside CNS)
Grading of primary brain tumours
graded according to how fast they grow + how likely they are to grow back (based on morphology) - also by WHO
- Garde 1 = low grade (low proliferation potential), benign (discrete) + associated with long term survival
- Grade 2 = low grade (typically benign but can transform into malig) - has ATYPIA + infiltrative but low mitotic activity -> can recur as high-grade
- Grade 3 = high grade. ANAPLASTIC (loss of mature/specialised features) + increased mitotic activity. Malignant.
- Grade 4 = high grade, v aggressive (reproduce rapidly). Anaplasia, mitotic activity + microvascular proliferation +/- necrosis - has disseminating potential
Complication associated with pineal region masses especially
tend to cause OBSTRUCTIVE HYDROCEPHALUS - tend to cluster in midline + compresses aqueduct -> signs + symptom of raised intracranial pressure
Monroe-Kellie Doctrine
- Skull fixed box consisting of Brain parenchyma (80%), Blood supply (10%), CSF (10%)
- Brain = 1400ml
- Blood = 150ml
- CSF = 150ml
- If change in make up of intracranial structure -> initially compensation
- Increased CSF drainage via ventricular system
- Increased venous drainage via dural venous sinuses
- non-linear relationship so as volume continues to increase, pressure suddenly rapidly increases: ie decompensation = signs/symps
Presentation of Brain tumour
Depends on type, grade + site
- typically if progressive over day/s weeks -> consider tumour
- but if long Hx of isolated headache -> probably not tumour (only 2% of brain tumour Px)
Symps:
-
Headache - from raised ICP (24% 1st symp)
- Associated N+V
- Worse when lying down/at night -> worse in morning; can wake Px up (caused by pressure increase when lying down)
- Exacerbated by coughing, sneezing, drowsiness (all increase ICP)
-
New onset/different SEIZURES (>80% - always check for brain tumours in adults presenting with seizures)
- more likely in temporal lobe tumours
- Focal neurological symptoms
- Non-focal symptoms
- Blurred vision from papilloedema
- Cognitive problems
- Personality/behavioural changes (e.g. disinhibtion or loss of motivation - could potentially be specific to frontal lobe)
- Cushing’s triad (bradycardia, irregular breathing/respirations, widened pulse pressure - raised BP but reduced HR)
Signs:
- Papilloedema
- Focal neurological deficit
- False localising (e.g. Diplopia due to 6th nerve palsey from raised ICP)
BRAIN METS associated with a lot of OEDEMA (so raised ICP symps)
+ lethargy + weight loss
Examples of the effects of seizures affecting different lobes e.g. in brain tumours
- Temporal lobe = affects emotions -> dread, deja/jamais vu
- Frontal lobe = motor, problem solving + personality/mood -> limb jerking, head/eye deviation, absence seizures
- Parietal = sensory -> sensory disturbance e.g. spreading tingling
- Occipital = vision -> +ve visual disturbance e.g. aura
Examples of focal neurological symps (not seizures)
- Weakness/loss of voluntary control (primary motor)
- Loss of skin sensation (primary somatosensory)
- Reduced problem solving; change in personality (frontal lobe)
- Speech disturbance:
- Expressive dysphasia (Broca’s - immediately anterior to primary motor, in frontal)
- Receptive dysphasia (Wernicke’s - posterior temporo-parietal border, in temporal)
- Hearing/memory problems (Temporal)
- visual loss with macular sparing (Primary visual - occipital)
- Loss of balance/co-ord (ataxia - Cerebellum)
- loss of consiousness, breathing or heart rate (brain stem)
Low grade vs high grade brain tumour symps
- Low grade - oft asymp till seizures or incidentally found
- High grade - raised intacranial pressure/rapidly progressing neurological deficit
4 examples of focal neurological deficit
- Hemiparesis
- Hemisensory loss
- Visual field defect
- Dysphasia
When is an urgent referral required for potential brain tumours/RED FLAG SIGNS
- Headache + other signs of raised ICP
- Headache with focal neurology (check for visual field defect as well)
- New onset focal seizure
- Rapidly progressive focal neurology even without headache
- Past Hx of cancer
Also:
- Age >50
- New onset CHANGE in previously existing headache
Dx of brain tumours
- 1st line + diagnostic = MRI Head +/- spine with contrast (gadolinium) (Diffusion weighted imaging)
- T1 weighted = black CSF -> tumour = hypointense
- T2 weighted = white CSF -> tumour = hyperintense (remember by thinking of Michael jackson)
- perfusion MRI to check level of malignancy (more perfused)
- can do functional MRI to check if any functional areas affected (if slow growing tumour - brain may have adapted + functional centres may be displaced to different sites than expected)
- Can do CT head if acute presentation (rule out haemorrhage, herniation etc) or if MRI unavailable/contraindicated
- Brain BIOPSY (determines grade based on histology, molecular markers + genetics)
- Othalmological evaluation; visual field testing (if issue suspected)
- CT chest/abdo/pelvis - check for secondary causes
Unusual to do lumbar puncture - Raised ICP can cause herniation upon puncturing
Prognostic factors of low grade gliomas
- Histology type
- AGE
- Size of tumour
- Rate of growth
- Location
- Crossing midline
- Presenting features
- Performance status (score that estimates Px ability to perform activities of daily living independently)
Prognostic factors of high grade gliomas
- IDH status (mutation is favourable)
- Performance status
- Extent of resection
- Older age at time of surgery
3 molecular/genetic variations particularly associated with brain tumours
- MGMT methylation (big prognostic factor!)
- if unmethylated - radiochemotherapy = less effective
- IDH mutation
- IDH wildtype results in progression of diffuse glioma to grade 4 Glioblastoma
- IDH mutant more likely to -> grade 2/3 Oligodendroglioma or Astrocytoma
- Still risk of grade 4 Astrocytoma
- Chromosome 1p19q loss (in oligodendroglial)
DDx of brain tumours
- Stroke (more sudden onset)
- Abscesses (typically thinner wall on imaging - surgical emergancy)
- Check Temp, WCC, CRP + MRI DWI
- Lymphomas - can spontaneoulsy regress with steroids
- makes diagnosis difficult if trying to biopsy
- MS (may have had similar episode years in the past)
Treatment of Low grade glioma
- SURGERY - EARLY RESECTION (risk of neuro damage)
- Radiotherapy + early chemo -> prolongs survival but risk of long-term issues e.g. dementia
Treatment of high grade gliomas
- STEROIDS (DEXAMETHOSONE) - increases WCC but REDUCES OEDEMA
- Optimise clotting/coag
- MAXIMAL SAFE SURGICAL RESECTION/Debulking (remove radiographically identified area of tumour + surrounding area as long as it is not functionally important)
- 5-ALA guided (pink drink that causes tumour to glow pink under ultraviolet light)
- Awake craniotomy -> allows CORTICAL MAPPING (checking effects of stimulating areas on Px) -> supramaximal resection
- may choose to not debulk if in functionally important area as unable to take out much anyways
- Intensive Radiotherapy
- Chemo = TEMOZOLOMIDE, PCV
Complications of surgery
- Wound infection
- CSF LEAK
- Neuro deficit
- Seizures
- Hydrocephalus (potentially due to blood in ventricles -> poor reabsorption of CSF)
- Thrombus related: DVT/PE, MI, CVA (ie stroke/TIA)
- recurrence/death
Factors affecting effectiveness of high-grade glioma treatment
- Various routes can be affected
- Interpatient variability
- Intratumoural heterogeneity
- Difficult to cross blood-brain barrier
What is a glioblastoma multiforme
AKA grade 4 astrocytoma - fast growing + v aggressive - invasive
Define a diagnosis of epilepsy
A condition characterised by recurrent epileptic seizures unprovoked by any immediate identified cause
Any of the following:
- At least 2 unprovoked seizures occuring more than 24hrs apart
- One unprovoked seizure + at least 60% probability of further seizures occuring within 10 years of 2 previous unprovoked seizures
- Diagnosis of epilepsy syndrome - a typically idiopathic cause of recurrent seizures
Define seizure
The transient occurrence of changes in behaviour, sensation or cognitive processes due to abnormal excessive, hypersynchronous neuronal activity in the brain
Pathophys of epileptic seizures
Shifting of balance between GABA and glutamate leading to increased glutamate stimulation + GABA inhibition -> Increased EXCITATION
Classification of epileptic seizures
- Focal - limited to 1 hemisphere
- Motor or non-motor
- Retained awareness = simple
- impaired awareness = complex
- Can be focal to bilateral spreading
- Generalised (originates in bilaterally distributed networks) - cortical or subcortical but not necessarily both simultaneously
- always loss of consiousness
Types of seizures
- Tonic-clonic (Most common)
- oft in phases: tonic phase = high frequency (continuous epileptic acitivity) -> rigidity, clonic = lower frequency but oft larger amplitude -> contraction
- Absence seizures (common in children, rarer in adults) - can be v quick + hard to spot
- Myoclonic = brief, shock-like muscle contractions
- Tonic = sudden onset, widespread muscle rigidity
- Atonic = spontanous muscle relaxation
Define status epilepticus
- Prolonged convulsive seizure lasting 5mins or more
or
- consecutive recurrent seizures without recovery in-between
Epidemiology of Epilepsy
- around 1% affected
- Higher incidence in low-income countries
- Higher rates in people with learning difficulties
- Highest risk of incidence in infants and ppl >50 y/o - BIPHASAL DISTRIBUTION
2/3 treated with just monotherapy but 30% (usually with co-morbidities) don’t respond well to treatment
Causes/RFx of Seizures
- Symptomatic epilepsy (most common in elderly)
- Head trauma
- oft presents with LoC >30 min + amnesia > 30min
- could be iatrogenic
- Cerebrovascular disease (infarct, haemorrhage, venous thrombosis)
- Brain tumour
- Head trauma
- Metabolic disorders (hypoglycaemia, hypo/hypernatraemia, hypo/hypercalcaemia - typically not K+)
- Infections
- v severe response to systemic - typically only in young children
- Encephalitis
- Drugs
- Isoniazid, Tricyclic antidepressants
- Alcohol misuse, cocaine
- Neurodegenerative disease e.g. Alzheimer’s (rarer)
- Sclerosis e.g. Mesial temporal sclerosis (common cause of focal)
- Idiopathic epilepsy (oft)
- can have genetic component esp in absence, myoclonic + primary generalised tonic clonic seizures