Anatomical Pathology Flashcards
T1 MRI shows
Lipid
Anatomy
Intracellular inclusions seen in Parkinson’s
Lewy bodies
T2 shows
Water
Nature of lesion
Mechanisms of cerebral oedema
Cytotoxic
Vasogenic
Cytotoxic oedema is…
Increased intracellular fluid secondary to cell membrane injury.
Eg hypoxia, toxins
Vasogenic oedema is…
Disrupted BBB leading to increased intercellular fluid.
Eg localized - adjacent to inflam, tumour
Generalized - entire brain
Egs of ring enhancing lesions
Abscess
Metastatic tumour
Late hemorrhage
Late infarct
Neonatal bacteria causing meningitis
E. coli
L monocytogenes
Childhood meningitis organisms
H influenzae
S pneumoniae
N meningitidis
CNS reaction types to viruses
- Acute myelo/meningo/encephalitis
- Post vaccinal/ acute perivenous demyelination
- SSPE
Types of extra cerebral haemorrhage
Epidural
Subdural
Subarachnoid
Causes of subarachnoid haemorrhage
Rupture of berry aneurysm
Idiopathic
Blood dyscrasias
Rupture of AV malformation
Define berry aneurysm
Internal elastic laminate damage with developmental arterial media defect at bi/trifurcation
Types of Intracerebral haemorrhage
Primary and secondary
Cause of primary intracerebral haemorrhage
Rupture of Charcot-Bouchard micro aneurysms of penetrating cerebral arteries
Who is most atrisk for primary Intracerebral haemorrhage
Middle aged to elderly hypertensives
Causes of secondary Intracerebral haemorrhage
Mycotic aneurysms AV malformations Thrombocytopenia Neoplasms Vasculitis
Types of lesions in traumatic haemorrhage
Focal (contusions, lacerations, coup and contrecoup)
Diffuse (diffuse axonal injury)
Most common site of brain tumour in children
Posterior fossa
Common midline brain tumours
Germinoma
Pituitary adenoma
Craniopharyngioma
Meningioma
Common CP brain tumours
Acoustic schwannoma
Meningioma
Common peri ventricular brain tumours
Ependymoma
Neurocytoma
Common parenchymal tumours
Glial - astrocytoma, oligodendroma, glioblastoma
Neuronal - neurocytoma
Common metastatic brain tumours
Ca lung, breast, colon
Melanoma
Choriocarcinoma
Therapy given for leukaemia in brain
Intrathecal cytotoxic therapy
Adaptive mechanisms for raised ICP
Reduce CSF
Pressure atrophy of brain
Reduce blood volume
False localizing sign in raised ICP
Kernohan’s notch
Cushing’s triad
Raised systolic BP
Bradycardia
Irregular breathing
Methods used to decrease ICP
Decrease CO2 (keep normocapnic) as CO2 dilated blood vessels Mannitol creates osmotic gradient taking water out of neurons
Major risk factors for stroke
HPT
Atherosclerosis
Previous stroke
Other risk factors for stroke
DM, CF, CAD, Afib
Three causes of ischemia in brain
Embolism
Thrombus
Hypotension
Types of infarct (5)
White matter infarction Laminar infarction Watershed infarction Pale infarction Haemorrhagic infarction
Mechanisms of haemorrhagic infarct in brain
Reperfusion of pale infarct
SSS thrombosis
Aetiology of anencephalocoele
Folate deficiency
Maternal DM
Anti epileptics
Alcohol
Grading in brain tumour increases with
Pleomorphism
Vascularity
Mitotic activity
Features of CNS blastoma
Large nucleus
Little cytoplasm
Minimal to no differentiation
Malformation
Morphological defect of part of an organ that resulted from abnormal developmental process
Deformation
Abnormal shape or position of body part due to abnormal MECHNICAL forces
Disruption
Morphological defect coming from breakdown or interference of originally normal development
Causes of malformations
Genetic
Teratogens
Multifactorial
Why NTDs higher in Transkei
Fumonism
Fungal mycotoxin in contaminated maize
Area of disorganized tissue in anencephaly
Cerebrovasculosa
Two treatment options for hydrocephalus
Endoscopic 3rd ventriculostomy
Ventriculoperitoneal shunt
Factors that reduce life expectancy in NTD
Chiari malformations
Hydrocephalus
Neurogenic bladder
Scoliosis
Charcot Bouchard aneurysms show
Intimate thickening
Medial fibrosis
Rupture of elastic lamina
Components of ring enhancing lesion
Central black = necrosis
White ring = leaking vessels
Black outer ring = vasogenic oedema
Why may subdural present late (even after bleed stops)
Breakdown of blood -> increased osmolarity -> fluid drawn into subdural region -> increased volume
Why aspirin contraindicated in subdural haemorrhage
Inhibits COX which in turn decreases amounts of PGG2 and PGH2. These are substrates for the formation of TXA2 which causes platelet aggregation and vessel vasoconstriction
Define macerated
Dead in utero and undergoing autolysis.
Dissolution of tissue due to enzyme breakdown following death
Five likely malformations in FASD
Heart defects Skeletal abnormalities Microcephaly Congenital hydronephrosis Anal agenesis
Common causes of congenital anomalies
Drugs - thalidomide, warfarin, retinoic acid
Alcohol
Maternal DM
Congenital infections = TORCHS
Features of congenital syphilis
Hydrops fetalis + placental oedema Pancreatitis HSM with pericellular fibrosis Osteochondritis Skin lesion Pneumonia alba
Cancers caused by alcohol in fetus
Embryonal tumours
Blastomas eg neuroblastoma
Extra renal Wilm’s tumour
Malignant mesenchymoma
Neurons most susceptible to ischemia
- pyramidal cells of hippocampus
- neocortex
- purine cells of cerebellum
Golden rules for primary brain tumours
- malignant tumours don’t show distant metastasis
- benign tumours don’t show distant metastasis
- benign can kill patients, malignant don’t always
- if parenchymal tumour can be shelled out, high grade malignant lesion
What pathology associated with subfalcine herniation?
ACA compression
Signs in congenital hydrocephalus
- macrocephaly
- widely separated sutures
- huge fontanelles
- relatively small face
- intellectual impairment, spastic paresis
- cerebellar ataxia
3 branches of ophthalmic nerve
Lacrimal
Frontal
Naso ciliary
Long term eye complications of diabetes
- diabetic retinopathy
- diabetic cataracts
Long term complications of diabetes in the foot
- gangrene (microangiopathy)
- diabetic foot
- peripheral neuropathy
Why are diabetics at risk for UTIs
- raise urinary sugar is a good culture medium for organisms
- obstruction of urethral from papillary necrosis
Mechanism for micro proteinuria in diabetics
- glycosylation of the BM of the glomerulus making it more permeable to proteins
Possible causes of easy bruising in leukemia
- thrombocytopenia
- splenomegaly (platelet sequestration)
- direct plt dysfunction
- DIC
Causes of granulomatous lymphadenopathy
- TB
- sarcoidosis
- fungal infection
- syphilis
Cardiac diseases that could result in cerebral infarct
- cardiomyopathy
- bacterial endocarditis
How ntds cause congenital hydrocephalus
- obstruction of foramen magnum by displaced cerebellum from the tethered cord
Complications of an untreated lumbar meningomyelocoele
- leg paraplegia
- urinary incontinence
- fecal incontinence
- ascending meningitis
Name of haemorrhage in adrenals
Waterhouse friderichsen syndrome
CNS effects in FAS
- microcephaly
- mental retardation
- hypotonia
- poor coordination
- hyperactivity
- sleep disorder
- spastic tetraplegia
- seizures
- hydrocephalus
Factors contributing to persistence of ulcers in diabetic foot
- peripheral neuropathy - repeated trauma and damage
- macroangiopathy (poor blood flow - poor healing)
- microangiopathy (poor blood flow)
- poor efflux of neutrophils from vessels
- raised glucose (prolif of bacteria)
Mechanism of AF leading to stroke
- decreased flow in atrial chamber
- increased thrombotic tendency
- thromboembolism
- MCA (straightest pathway)
Mechanism of AF in chronic rheumatic heart disease
- myocarditis (damage and fibrous repair)
- MS (damage and repair by fibrosis)
- muscle hypertrophy ( increased o2 demand)
- interruption of electrical pathway
Congenital abnormalities associated with FAS
- congenital heart defect
- skeletal abnormality
- microcephaly
- congenital hydronephrosis
- anal agenesis
Ocular signs in raised ICP
- pupillary dilation
- papilloedema
- CN 3 weakness
