Central nervous system
Edema and hydrocephalus, malformations, trauma, vascular disease, infections, demyelination, neurodegeneration and tumours.
42 pages
Lesion
- Acute meningitis: pyogenic vs asepticMeningitis is infection of the brain's coverings; bacteria give pus and an emergency, viruses…
- Adult diffuse gliomasDiffuse gliomas grow into normal brain like roots; glioblastoma, the worst, shows dead zones…
- Alzheimer disease: plaques and tanglesAlzheimer disease is the commonest cause of dementia: amyloid plaques build up between neurons…
- Berry aneurysm and subarachnoid hemorrhageA berry aneurysm is a thin pouch at a fork of the brain's arteries; when it bursts, blood fills…
- Brain abscess and empyemaBacteria can reach the brain from sinuses, ears, teeth, the blood or wounds and form a pocket of…
- Brain and spinal cord traumaA blow or a sudden stop can crack the skull, bruise the brain where it hits bone, shear axons…
- Brain malformations: forebrain and posterior fossaBrain malformations arise when cells are too few, move to the wrong place or fold wrongly; many…
- Brain metastases and paraneoplastic syndromesCancers from the lung, breast, skin and kidney often spread to the brain; others act at a…
- Cerebral infarctionWhen one brain artery is blocked, the tissue it feeds dies and liquefies; the age of the infarct…
- Chronic bacterial meningoencephalitis: TB, syphilis, LymeTuberculosis, syphilis and Lyme disease can smoulder in the brain for weeks or years, causing…
- Ependymal, choroid plexus and glioneuronal tumoursTumours from the ventricle lining and choroid plexus block CSF flow; mixed neuronal tumours are…
- Epidural vs subdural hematomaEpidural bleeds are arterial and fast, between skull and dura; subdural bleeds are venous and…
- Frontotemporal lobar degenerationFrontotemporal degeneration shrinks the frontal and temporal lobes, changing personality and…
- Fungal infections of the CNSFungi reach the brain mostly in people with weak immunity, causing chronic meningitis, abscesses…
- Global hypoxic-ischemic brain injuryWhen the whole brain loses blood or oxygen, as in cardiac arrest, the most sensitive neurons die…
- Herpesvirus encephalitisHerpes simplex type 1 is the most common cause of serious sporadic encephalitis; zoster and CMV…
- HIV in the brain and PMLHIV can damage the brain directly and opens the door to infections such as JC virus, which…
- How brain cells react to injuryNeurons cannot divide, so they show injury by shrinking, swelling or storing debris; astrocytes…
- Huntington disease and inherited ataxiasHuntington disease destroys the caudate and causes chorea and dementia; inherited ataxias wear…
- Inherited metabolic diseases of the brainMissing enzymes can fill neurons with stored material, destroy white matter or starve the brain…
- Medulloblastoma and other embryonal tumoursMedulloblastoma is the commonest malignant brain tumour of children: small blue cells in the…
- MeningiomaMeningiomas grow from the brain's covering, are usually slow and benign, and press on the brain…
- Metabolic and toxic brain injuryLow sugar, ammonia from a failing liver and poisons such as carbon monoxide, alcohol and…
- Motor neuron diseasesMotor neuron diseases kill the nerve cells that move muscles; ALS takes both upper and lower…
- Multiple sclerosis: the plaqueIn multiple sclerosis the immune system strips myelin from nerve fibres in the brain and cord…
- Neural tube defectsIf the neural tube does not close in the fourth week, brain or spinal cord stay open or bulge…
- Other demyelinating diseasesSeveral diseases besides multiple sclerosis destroy myelin: antibody attacks on astrocytes…
- Parasitic brain infectionsPork tapeworm larvae, Toxoplasma, amoebae and malaria can all attack the brain…
- Parkinson disease and Lewy body disordersIn Parkinson disease, dopamine neurons of the substantia nigra die and alpha-synuclein clumps…
- Perinatal brain injuryBabies born early or deprived of oxygen around birth can bleed into fragile brain tissue or lose…
- Pilocytic astrocytomaPilocytic astrocytoma is a slow, well-defined childhood tumour, often a cyst in the cerebellum…
- Poliomyelitis and rabiesPoliovirus kills motor neurons and leaves floppy paralysis; rabies travels up nerves to the…
- Primary CNS lymphomaPrimary CNS lymphoma is a B-cell cancer that starts in the brain, eyes or spinal cord, mostly in…
- Prion diseasesPrion diseases are caused by a misfolded protein that converts normal copies; they cause rapid…
- Small vessel disease: hypertensive and amyloid hemorrhageYears of high blood pressure or amyloid damage the brain's tiny arteries, which then bleed or…
- Thiamine and B12 deficiency in the CNSLack of thiamine damages memory and eye-movement centres; lack of B12 damages the back and side…
- Vascular malformations of the brainSome brain vessels form abnormally from birth: tangles of arteries and veins or clusters of thin…
- Viral encephalitis: the shared patternViruses that infect the brain leave a common footprint of lymphocytes around vessels and…
Mechanism
Topic
- CNS tumours: an overviewBrain tumours are now named by both their look and their genes; even ‘benign’ ones can kill by…
- Familial tumour syndromes of the nervous systemSome families inherit a faulty tumour-suppressor gene that causes many nervous system tumours…
- Neurodegeneration: the protein tableMost neurodegenerative diseases share one theme: a misfolded protein clumps inside or outside…
A to Z
Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.
Representative model, for educational purposes only.