Pathology Flashcards
Specific Symptoms Of Demyelinating
Unexplained optic neuritis
Ophthalmoplegia (MS)
Genetic Factors Of MS
Strong association with a DR (2 and 15 in clinical medicine) haplotype of MHC
Associations with IL-2 and IL-7 receptor genes
Active Plaques On Microscopy
Centred on small veins
CSF In MS
- Elevated protein
- Serum Glucose: Normal
- Lymphocytes
- Macrophages
- Plasma cells
- Increased IgG
- Oligoclonal IgG bands on immunoelectrophoresis
Non-demyelinating Ddx Of MS
- Spinal cord neoplasms
- Sarcoidosis
- Infarction of spinal cord
- Vasculitis
- Arteriovenous fistula
NOM Antibody + Component
SEARCH THE ANTIBODY
Aquaporin-4
Subacute Combined Degeneration Of SC Paraesthesia Direction
Ascending paresthesias
Tertiary Syphilis Diagnosis
Clinical exam
History
Serology
Hypoxic-ischaemic demyelination areas
Affects globus pallidus and white matter
Pathophysiology:
Anti-MAG Neuropathy
POEMS Syndrome
Anti-MAG Neuropathy - Monoclonal IGM Gammopathy
POEMS Syndrome - Plasma Cell Neoplasm
Selective Vulnerability
Neurons are the most vulnerable cells in the CNS to ischemia
◦ e.g pyramidal neurons in the hippocampus, and Purkinje cells in the cerebellum.
Pick body locations
These are tau-immunopositive bodies predominantly
located in granular neurons in the hippocampal dentate gyrus,
hippocampal CA1 pyramidal neurons, and layer II of frontal and
temporal cortices.
IgG Index
- IgG index is derived from the following formula:
IgG In= [IgGCSF/albuminCSF]/ [IgGserum/albuminserum]
CNS Tumour Common Types For Age
Adults (70% supratentorial – Intrinsic + extrinsic - 65% primary intrinsic):
Astrocytoma
Glioblastoma (COMMONEST IN BOTH AGE GROUPS)
Meningioma
Metastatic
Oligodendroglioma
Children (Children - 70% infratentorial – Intrinsic - all primary intrinsic):
Astrocytoma (COMMONEST IN CHILDREN - 50%)
Medulloblastoma (45%)
Tumours with hydrocephalus in children occur in which cranial fossa usually?
Posterior fossa tumours
Diagnosis Of Brain Tumours
MRI!!! Higher and better sensitivity, resolution, and three planar views
MRI with gadolinium contrast is the gold standard
MRI better than CT: Tumor of suprasellar, optic path, infratentorial & pituitary region
Lumbar puncture indications in tumours
Indication:
Medulloblastoma
Ependymoma
Germ cell tumours
Contraindications:
Newly dx hydrocephalous sec. to CSF flow obstruction
Tumour causing supratentorial midline shift
Infratentorial tumours
What primary brain tumours are highly malignant?
Glioblastoma
Medulloblastoma
Factors in the aetiology of CNS neoplasms
- Sex – gliomas commoner in males
- Exposure to ionizing radiation implicated in
immunodeficiency - Primary CNS lymphoma – is associated with 4. No convincingevidence has linked CNS neoplasms
with trauma, occupation, diet, electromagnetic
fields
meningiomas commoner in females ~ meningiomas ~ gliomas ~ nerve sheath tumors
Tumours are now divided based on whether cells have mutations in which genes?
Tumors are now divided based on whether the cells have mutations in one of the IDH genes (IDH1 or IDH2). For a specific type of tumor, those with IDH mutations tend to have a better outlook.
Primitive neuroectodermal tumours/medulloblastoma (not sure which one she meant) molecular subtypes
Wnt pathway activation - gene for β-catenin –good prognosis Hedgehog pathway activation-mutations in PTCH1–intermediate MYC overexpression – poorest prognosis
Wnt and HH lead to personalised therapy
How is PCNSL diagnosed?
Stereotactic needle
DO LAILA’S SUMMARY ON GENES
At end of the note
Distribution of pus in meningitis
Pneumococcal - convexities + near sagittal sinus
H. influenzae - basal (hence the cranial deficiencies)
Are fibroblasts part of brain abscesses?
NO we have gliosis
Which organism shows a spiderweb appearance when the lumbar tap test tube is left standing?
TB
Basilar meningitis causes
H. influenzae
TB
Histoplasma capsulatum
Viral meningitis and encephalitis r/shp
Encephalitis is accompaniedby viral meningitis whereas aseptic meningitis may occur alone. (unrelated to this card but herpes can reach CNS by olfactory)
Viral Neurotropism
(1) Neurons – eg. Herpes, polio, rabies, SSPE
(2) Astrocytes – eg. Herpes, SSPE
(3) Oligodendro glial cells – eg. Papova (JC, SV40)
This tropism is influence by :
(1) Viral factors
(2) Host factor
Herpes – HSV1 – temporal lobes
Polio – Anterior horn cells of spinal cord
Rabies – Ammon’s horn (hippocampus), Purkinje cells
HSV Diagnosis
Polymerase chain reaction — Gold standard - Detects HSV DNA in CSF -sensitivity (98 %),specificity (99%)
Is positive early in the course of illness.
Brain biopsy (not used anymore) — Prior to PCR testing, was only way to diagnose HSVE. Now only role in patients with clinical
deterioration despite antiviral therapy or if alternative diagnosis is considered. Examines for HSV by
Culture
HSV antigens by IHC
Viral DNA by in situ hybridization
Not done routinely as invasive and can lead to sequelae
Viral culture of CSF is rarely positive in the early infection
CSF antigen and antibody determinations — not helpful in early diagnosis
Triad of congenital toxoplasmosis
Triad of chorioretinitis, hydrocephalus, and intracranial calcifications.
Diagnosis of cryptococcus neoformans
Microscopic examination
Culture of tissue or body fluids such as blood, CSF, and sputum
Cryptococcal antigen test is a rapid test that can be performed on blood and/or on CSF
Which stroke has the most rapid onset?
Embolic stroke
Where does ICH usually occur?
Cerebellum and basal ganglia
Berry aneurysm distribution
- ACA and ant. comm. artery junction (more on comm.)
- MCA
- ICA and post. comm. junction
- Bifurcation of basilar
Lacunar infarct cause
HT + lenticulostriate arteries of BG, internal capsule, putamen, thalamus, pontine tegmentum,
cerebellum.
Recap salah humood
Week 5
