Neuro PATH Flashcards
Chronic menigitis causes ?
- TB
- Cryptococcus
Pyogenic meningitis causes by age
Neonate-
Young adult-
Older pts-
Neonate
- E-coli
- Group B strep
Young adult
- Neisseria Meningitidis
Older patients
- Strep pneumonia, listeria, H-influenza
Aseptic meningitis causes
- Enterovirus
- Self limiting
CADASIL
- inheritance ?
AD
CADASIL
- affects small, medium or large vessels ?
- Small vessel vasculopathy without stroke risk factors*
CADASIL
- mutation ?
NOTCH 3 gene on Chromosome 19
CADASIL small vessel morphology ?
- Fibrotic thickening of basement membrane
- No atherosclerosis or amyloid deposition
- Diagnosed with gene testing*
CADASIL affects which part of brain ?
- Basal ganglia (most common) >
- Paramedian superior frontal lobe**
- Parietal lobe
- External capsule*
- Anterior temporal lobe** (classic)
- Cerebral cortex and U-fibers spared**
What’s unique about CADASIL infarcts ?
- Infarcts cross arterial territory
- Less frequently hemorrhage
- Diagnosed with skin/muscle biopsy**
4 types of vascular malformations ?
- AVM
- Cavernous malformations
- Capillary telangiectasia
- Venous angiomas
of the 4 types of vascular malformations, which type are associated with hemorrhage and development of neurologic symptoms ?
- AVM
- Cavernous malformations
AVM associated with what mutation ?
KRAS oncogene mutation
AVM vs Cavernous malformation
AVM
- intervening gliotic tissue
- no intervening capillary
- often have prior hemorrhage
- most common MCA territory posterior* branch
- AD familial form are common (will have multiple)
- High flow (dAVF, pial AVF, then everything else low flow)
Cavernous malformation
- No intervening brain
- Most common in cerebellum > pons > subcortical
- Low flow
- Old hemorrhage as well
Capillary telangiectasia (hemangioma) RF ?
- Radiation*
Sinus Pericranii
- Anomalous communication between intracranial dural venous sinus, extracranial venous
circulation. - Majority congenital.
- Probable anomalous venous development during late embryogenesis.
- Incomplete sutural fusion over prominent/abundant diploic or emissary veins.
- In utero DVS thrombosis*.
Capillary telangectasia
- Cluster of dilated, but histologically normal capillaries. - Thin-walled, endothelial-lined vascular channels, largest channels may represent draining veins.
- Normal brain interspersed between dilated
capillaries. - No surrounding gliosis, hemorrhage or calcification.
Developmental venous anomaly
- Radially oriented dilated medullary veins.
- Separated by normal brain.
- Normal white matter (no gliosis).
- 20% have mixed histology (CM most common), may hemorrhage.
- Variant: “Angiographically occult” DVA
Summary of tumor grades
Grade 1
- well circumscribed
Grade 2
- Poorly circumscribed
Grade 3
- Mitotic cells and atypia
Grade 4
- Necrosis and angiogenesis
Diffuse Astrocytic and Oligodendroglial Tumours ?
IDH Mutant (1p/19q codeletion present)
- Oligodendroglioma (grade 2)
IDH Mutant (1p/19q codeletion absent)
- Diffuse astrocytoma (grade 2)
- Anaplastic astrocytoma (grade 3)
IDH Wild type
- GBM (grade 4)
H3K27M
- Diffuse midline glioma (grade 4)
Ependymal tumors ?
- Myxopapillary ependymoma : grade 1
- Ependymoma : grade 2
- Anaplastic ependymoma : grade 3
- Subependymoma : grade 1
Choroid Plexus tumours (all enhance a lot)
- Choroid plexus papilloma (grade 1) - kids
- Atypical choroid plexus papilloma (grade 2)
- Choroid plexus carcinoma (grade 3) - adults
Neuronal and Mixed Neuronal-Glial Tumours
Grade I
- Dysembryoplastic neuroepithelial tumour (DNET)
- Ganglioglioma and gangliocytoma
- Desmoplastic infantile astrocytoma and ganglioglioma
- Dysplastic gangliocytoma of the cerebellum (Lhermitte-Duclos)
Embryonal Tumours
All are WHO 4
- Medulloblastoma
- Atypical teratoid/rhabdoid tumour
- CNS neuroblastoma
- CNS ganglioneuroblastoma
- Medulloepithelioma
Arachnoidal Tumours
All Meningiomas basically
Craniopharyngioma arises from?
- Rathke pouch remnant
- Epithelial tumor*
- Benign grade 1 tumor
Craniopharyngioma clinical presentation
- Growth retardation due to pituitary dysfunction (Growth hormone deficiency)
- Headache and visual disturbance
Ependymoma epidemiology
- Bi-Modal
- first peak 1-5 year old (A subtype)
- second peak mid 30s (B subtype)
Ependymoma arises from ?
- Glial cells of ependymal lining of ventricles / ependymal rests
Ependymoma subtype and prognosis and location ?
60% infratentorial - 2 subtypes in the posterior fossa
- Subtype A: Most common, predominately infants, poor prognosis
- Subtype B: Older children and adults, better prognosis
10% spinal
Supratentorial Ependymoma location ?
- Extra-ventricular (most)*
- if intra-ventricular will be in 3rd ventricle*
supratentorial ependymoma, ZFTA (RELA) fusion-positive (POOR PROGNOSIS)
supratentorial ependymoma, YAP1-MAMLD1 fusion
Ependymoma microscopic ?
- Perivascular Pseduorosettes**
Myxopapillary ependymoma seen, next step ?
- MRI whole spine
- Benign but up to 50% do have leptomeningeal disease at time of diagnosis so must image neural axis
- Despite this, excellent prognosis*
GBM associations ?
- NF-1
- Li-Fraumeni
- Turcot
- Ollier
- Maffuci
Uncal herniation causes:
- Duret Hemorrhages from basilar perforating arteries
- CN3 compressed between PCA and SCA causing ipsilateral pupil dilatation and ptosis
- “Kernohan’s Notch”: Ipsilateral hemiparesis. Mid brain compresses tentorium, cerebral peduncle on contralateral.
HTN causes what vessel changes
Accelerated atherosclerosis
- larger arteries
Hyaline arteriosclerosis + Hyperplastic
- small arteries
- vulnerable to rupture
Lipohyalinosis –> Charcot buchard microaneurysm
- basal ganglia
- site of rupture
Fibrinoid necrosis
- small vessels
In amyloid angiopathy there is deposition of AB in the walls of medium to small meningeal and cortical vessels - PERIPHERAL rather than central*
Global hypoxic ischemia
- most common site
- Diffuse cortical Grey Matter perirolandic cortex (affected first)
- Watershed infarcts after hypotensive episodes*
- Cerebellum (more common in older patients)
- Diffuse white matter
Meningioma morphology types
Rounded “globose”
- well defined dural base
- CSF cleft between tumour and cortex
En plaque
- sheet like over dura
- Hyperostosis*
–> Psamomma bodies
Meningioma genetic mutations
- loss of chromosome 22** (most common)
- NF2 mutation seen in sporadic (60%) and almost all high grade meningiomas
Define grade II and III Meningioma features
Grade II = < 20 mitoses / brain invasion / 3 atypical features*
Grade III = overt malignancy cytology or 20 mitoses / 10 HPF*
Multiple Sclerosis epidemiology
- Female
- Peak at 35
MS pathophysiology
- Autoimmune attack against myelin sheath
- EBV associated
MS active vs chronic plaque
Active
- Periventricular
- Myelin breakdown with abundant macrophages
- Lyphocytes as perivascular cuffs
Chronic
- Marked loss of Myelin and Oligodendrocytes
- Astrogliosis**
- No perivascular inflammation
MS Macroscopy
- Firmer than surrounding white matter due to sclerosis
Clinical presentation, Inclusions, Genetic for:
Prion disease
Alzheimer
FTLD
Parkinson
PSP
Corticobasal degeneration (CBD)
MSA
Huntington
ALS
SBMA
Prion
- Rapid progerss dementia
Alzheimer
- AB (plaques)
- tau (tangles)
- Trisome 21, PS-1, PS-2, APP
FTLD
- Behavioural, Language change
- Tau*
- TDP-43*
Parkinson
- a-synuclein
- tau
- Lewy bodies
PSP
- Parkinson + abnormal eye movement
- tau
Corticobasal degeneration (CBD)
- Parkinson + asymmetric movement disorder
- tau
MSA
- Parkinson + cerebellar ataxia + autoimmune failure**
- a-synuclein
Huntington
- AD
- Hyperkinetic movement (Chorea)
- HTT gene**
ALS
- weakness with upper and lower motor neuron signs
- SOD1
- TDP43
- FUS
SBMA
- Lower motor neuron weakness and low androgen
- Androgen receptor
Huntington
- Inheritance
- Gene
- Image
- AD
- HTT gene with tri-nucleotide repeat
- loss of GABAergic neurones at BG
- Atrophy caudate head and putamen + box-like frontal horn
MSA
- inheritance
- gene
- Sporadic
- Parkinson + cerebellar ataxia + autoimmune failure**
- a-synuclein
Oligodendroglioma macroscopic appearance
- Cystic degeneration, Calcification, Hemorrhage common
- Remodelling of adjacent bone
- Supratentorial (adult)
- Posterior fossa and spinal cord (children)
- Fried egg appearance of tumor cells
- Chicken wire pattern of microvasculature
Pituitary adenoma epidemiology
- peak 35-60
- 15% found on autopsy*
- most are non-functional microadenomas*
–> Pituitary carcinoma is rare, <1% of all pituitary tumours. Mostly functional. Differ from adenomas due to the presence of distant metastases.
Least common pituitary hormonal abnormality
- TSH (1%)
Pituitary adenoma RF
- MEN-1
Pituitary adenoma aetiology
- due to Mutation of G-protein
- Sporadic (most)
Pituitary adenoma macroscopic appearance
- Cyst, necrosis and hemorrhage in large adenomas
- Calcifications in Prolactinomas*
HSV-1 affects who ?
- adults and young children
- Accounts for 90% of Herpes simplex encephalitis
HSV-2 affects who ?
- neonates and immunocompromised
CMV, HIV, JCV afects who ?
- Immunocompromised
HSV encephalitis brain imaging feature ?
- Medial temporal lobe*
- Spares basal ganglia
- restricted diffusion (earliest sign, most sensitive)
Limbic encephalitis looks similar**
Limbic encephalitis imaging feature ?
(if they say HSV titer is negative..then its this)
- Paraneoplastic syndrome from small cell lung ca*
- Looks like HSV encephalitis on imaging:
- Medial temporal lobe* (same as HSV encephalitis)
- Spares basal ganglia
Microscopic finding of HSV encephalitis
- Cowdry Bodies**
- Perivascular inflammation
HIV encephalitis is a chronic or acute inflammation ?
- Chronic inflammation
- Associated with microglial nodules**
- Aseptic meningitis occur after seroconversion
PML preferentially infects what type of brain cells ?
- Oligodendrocytes*
- leads to demyelination*
What are causes of Basal meningitis ?
- Cryptococcus
- TB
- Sarcoidosis
SAE association
- HTN (strong association)**
SAE imaging ?
(looks like CADASIL)
- ONLY involves white matter
- Centrum semiovale white matter*
- Fronto-temporal horn (classic)
- Spares U-fibers
- Seen in >55yo
Alzheimer vs Vascular dementia vs Lewy body dementia
- imaging features
Alzheimer
- hippocampal, temporal lobe atrophy
- FDG posterior temporoparietal uptake (ear muff)
Vascular Dementia
- Cortical infarcts
- Lacunar infarcts
- Generalized brain atrophy
Lewy body dementia
- Generalized atrophy
- a-synuclein*
- clinically like Parkinsons, but dementia comes before parkinsonism
- Visual hallucinations**
MELAS features
(MELAS)
- Mitochondria disorder
- Lactic Acidosis
- Seizures
- Strokes (in non-vascular distribution)
- normal WM
Adrenal Leukodystrophy (ALD)
- Imaging ?
- F or M more common
- Parietal occipital predominance
- Crosses splenium of Corpus Callosum
- MALE predominance
- can Enhance, restrict
Metachromatic
- Imaging ?
- Frontal lobe
- Periventricular Tigroid
- Spares U-fibers
- Most common leukodystrophy*
Multifocal brain tumors from seeding ?
- Medulloblastoma
- GBM
- Oligodendroglioma
- Ependymoma
Germinoma of pineal gland*
- epidemiology
- Exclusively in BOYS
- the MOST COMMON pineal gland tumor
Germinoma pineal gland labs ?
- high bHCG
Pineoblastoma resembles what other tumors ?
Small round blue cell tumor, pNET of the pineal gland. WHO grade-4 highly aggressive tumor.
Resembles:
- Medulloblastoma (pineoblastoma also highly aggressive and often seeds)
- Retinoblastoma
Pineoblastoma epidemiology
- girls (c.f. germinoma is boys)
Pineoblastoma association ?
- Retinoblastoma (5% with retinoblastoma gets pineoblastoma)
Pineoblastoma labs
- Homer Wright rosettes and Flexner-Wintersteiner rosettes
- synaptophysin: positive
- chromogranin-A
- neurone-specific enolase: positive
Pineocytoma epidemiology ?
- Adult
- RARE in childhood (c.f. pineoblastoma and germinoma)
- non-invasive, well circumscribed (c.f. pineoblastoma)
Most common neonatal brain infection ?
- CMV (3x more common than toxo)
- Polymicrogyria (highest association amongst TORCH)
What trimesters does TORCH infection matter most ?
- only matter in the first two trimesters (doesn’t cause much harm in third)
Calcification pattern of CMV vs Toxo
- CMV (periventricular)
- Toxo (Basal ganglia with hydrocephalus)
Most common opportunistic infection in AIDS ?
Toxoplasmosis
CJD 3 types ?
- Sporadic (90%)
- Variant “mad cow” (rare)
- Familial (10%)
CJD imaging
Restricted diffusion most sensitive sign
- Cortex (most common early site)
- Basal ganglia
- Progressive brain atrophy**
Hockey stick (variant)
- FLAIR dorsal medial thalamus
Pulvinar sign (variant)
- FLAIR pulvinar thalamic
Things that involve corpus callosum
- Tumor: Lymphoma (most classic), GBM
- Post Treatment: Radiation Necrosis
- Demyelination; Big Tumefactive MS Plaque, Marchiafava-Bignami
- Infection: Progressive Multifocal Leukoencephalopathy (PML)
- Trauma: Diffuse Axonal Injury
- Weird Shit: transient lesions of the splenium of the corpus callosum - cytotoxic stuff often from seizure medications (oval spot in the splenium)
Bilateral thalamic stroke differentials
- Artery of Percheron (arise from PCA)
- Tip of basilar occlusion
- Bilateral internal cerebral vein thrombosis
Caudate infarct which artery affected
- Recurrent artery of Heubner stroke (from ACA, can be due to clipping of ACOM aneurysm)
Infarct in Anterior and Posterior circulation of the same hemisphere
- Fetal PCOM stroke
Fusiform aneurysm association and site
Association:
- PAN
- Syphilis
- Marfans, Ehlers Danlos
Location:
- Posterior circulation
2 types of paraganglioma and locations
Parasympathetic paragangliomas
- Carotid body paraganglioma (most common - 40-60%)
- Jugular Paraganglioma (invades occipital and petrous apex)
- Jugulotympanic paraganglioma (erodes middle ear)
- Tympanic paraganglioma (doesnt erode middle ear)
Sympathetic paraganglioma
- Intra-adrenal: Pheochromocytoma (most common)
- extra-adrenal: organ of Zuckerkandl, bladder, mediastinum
Jugular Paraganglioma
- Epidemiology
- Clinical presentation
- Imaging
Epi
- 40% hereditary*
Presentation
- Hoarseness from vagal nerve compression (most common)
Imaging
- Can erode middle ear, petrous apex, occipital bone
- Salt and pepper
- FDG-avid
Cholesterol Granuloma
- imaging ?
- most common petroud apex lesion with smooth bony expansile lesion
- T1 and T2 bright
- T2 dark hemosiderin rim and faint peripheral enhancement
- slow growing one can watch and wait, fast growing needs surgery
Cholesteatoma in petrous apex
- congenital or acquired ?
- how to tell from cholesterol granuloma
- these are Congenital (c.f. middle ear cholesteatoma is acquired)
- slow growing with similar bony changes to Cholesterol Granuloma
- T1 dark, T2 bright with restricted diffusion* (c.f. Cholesterol granuloma is T1, T2 bright, No restricted diffusion)
Malignant “Necrotizing” Otitis externa
- Causing agent ?
- Risk factor ?
Causative agent
- Pseudomonas (always)
Risk factor
- Diabetics* (always)
Swollen EAC soft tissue with small abscesses and bony erosion
phthisis bulbi causes
IMage: Shrunken, crenated appearance of the left globe with associated calcification
Cause
- chronic end-stage condition due to severe ocular insults
- Traumatic injury
- Infection, or radiation.
What is LEAST LIKELY to be associated with enlarged nerves of the cauda equina?
Dejerine-Sottas
Hereditary sensory motor neuropathy
Guillain-Barre syndrome
Metastatic adenocarcinoma
Guillain-Barre typically shows diffuse cauda equina enhancement, but does not enlarge the nerves.
- Chronic demyelinating polyneuropathies such as
- Dejerine-Sottas and HSMN will enlarge the nerves of the cauda equina.
- Leptomeningeal metastases will also enlarge the roots in a nodular pattern.
Saccular aneurysm in how many % population ? how many % multiple
2% of populatoin
- 90% are found near major branch points in anterior circulation.
- 10% posterior
Up to 30% multiple
Features of intracranial hypertension
- papilloedema: flattening of the posterior sclera (~80%)
- Prominent subarachnoid space around the optic nerves
- Tortuous optic nerves
- Empty sella
- Enlarged Meckel cave
- Slit like ventricle
Optic neuritis bilateral
- NMO (devics)
ischemic optic neuropathy in Vasculitis can look like ?
Optic neuritis
Rectus pseudotumor or thyroid disease show tendons sparing
Pseudotumor
- Involves unilateral rectus muscle most common
- involves tendons
- will see peri-orbital oedema (if dont seen, then dealing with real tumor)
JNA most common arterial supply
Internal maxillary artery of the external carotid artery
Craniocynosotosis associations
- Apert syndrome
- Crouzon syndrome
- Carpenter syndrome
- Choanal atresia
What are some conditions that are associated with BBB disruption besides Infarct, Tumor, Infection ?
- Temporal lobe epilepsy (TLE)
- Posterior reversible encephalopathy syndrome (PRES)
- Hypoxia, ischaemia and infarction, tumour
- Inflammatory conditions, e.g. meningitis, trauma, intracranial irradiation, multiple sclerosis,
progressive multifocal leukoencephalopathy: the JC virus can cross the BBB.
Examples of Communicative hydrocephalus ?
- meningitis, haermorrhage, overproduction of CSF
Which vascular malformation has NO normal intervening brain tissue ?
Cavernous haemoangioma
Which vascular malformation angiographically occult ?
DVA
