Lecture 13 Flashcards
(36 cards)
what is meningitis
it is an inflammatory process, usually caused by infection.
chemical meningitis can occur in response to a nonbacterial irritant in the subarachnoid space
acute pyogenic meningitis (bacterial meningitis)
in what ages ar the most common bacterias
bacteria causing
in neonates the most common is escherichia coli and group B strep
in adolescence and in young adults neisseria meningitis is the most common pathogen
in older patients strep pneumonia and listeria monocytogenes are most common
what is aseptic meningitis
inflammation of the meninges not caused by bacteria and due to viral infection
symptoms: neck stiffness, fever, change in consciousness, it is less severe
in the CFD we usually find lymphocytosis ( increased lymphocytes) , moderate protein elevation, normal glucose levels.
brain abscess
caused by bacterial infections
infection can reach the brain via direct implantation, local spread, hematogenous spread
viral encephalitis
infection that affects the brain itself usually accompanied by inflammation of the meninges
Fungal Encephalitis
Fungal infections of the brain typically cause granulomas or abscesses in the brain tissue (parenchyma), and are often associated with meningitis. Each fungus tends to show a distinct pattern:
- Candida albicans
Usually causes multiple microabscesses
May or may not form granulomas - Mucormycosis (Mucorales family)
Causes rhinocerebral infections (nose/sinuses)
Classically seen in diabetics with ketoacidosis
Spreads to the brain via:
Vascular invasion
Direct extension through the cribriform plate - Aspergillus fumigatus
Strong tendency to invade blood vessel walls
Leads to widespread hemorrhagic infarctions due to thrombosis - Cryptococcus neoformans
Seen in immunocompromised patients
Causes meningitis or meningoencephalitis
May be:
Fulminant and fatal within 2 weeks
Or slow and chronic, lasting months to years
what are the signs for meningitis
kernels sign –> stiffness of the hamstrings, instability to straighten leg when the hip is flexed to 90 degrees
brudzinskis sign –> supine position, passive flexion of neck, spontaneous flexion of the hips and knees
cysyicercosis
consequence of end stage infection by the tape worm Xenia solium.
cysts can be found throughout the body but are mainly common in the brain the the subarachnoid space it can causes seizures
prion disease
(TSE) neurodegredation, vacillation and deposition of the abnormal prion protein
symptoms:
- loss of motor control
- dementia
- paralysis
- encephalitis
- wide spread neuronal loss
it can be hereditary spread or infectious via diet, surgical procedure like corneal transplants
creutzfeldt Jakob disease
it is rapidly progressive, neurodegenerative disorder, caused by prion protein
we have 3 categories:
- sporadic: individual has no risk factors
- hereditary: family history
- acquired: exposure to brain/ nervous system tissue
symptoms:
personality change, depression, ataxia, insomnia, dementia, involuntary jerky movements
primary disease of myelin
- multiple sclerosis –> inflammatory and demyelinating disease, progressive, body own immune cells attack the nervous system and the myelin is destroyed, cause is unclear but can be environmental or hereditary. signs: vision impairment, tingling, difficulty walking, memory loss
- lysosomal storage disease
3) peroxisomal disorders e.g Zellweger syndrome
metabolic disorders
hypoglycaemia: low glucose can cause global hypoxia the highly venerable areas are hippocampal neutrons and spared areas are cerebellar purkinje cells
hyperglycaemia: seen in poorly controlled diabetes mellitus
I can occur in diabetic ketoacidosis and hyperosmolar coma and it can lead to confusion, coma and stupor and it is caused by intracellular dehydration from a high blood sugar
hepatic encephalopathy:
caused by liver dysfunction, accumulation of neurotoxic substances
list of toxins that can effect the bairn
metals such as:
- lead ( diffuse encephalopathy)
- arsenic and mercury
- organophosphates in pesticides
- environmental polluters such as carbon monoxide
- ethanol In high doses can lead to cerebellar dysfunction
alzheimers
degenerative brain disorders –> progressive memory loss, impaired thinking, disorientation and changes in personality and mood, degeneration of brain neurone esp in the cerebral cortex and presence of neurofibrillary tangles and plaques containing beta amyloid cells
attacks the nerves and the brain and neurotransmitters, causes plaques and bindles
frontotemporal dementia
deterioration of personality. prominent frontal and temporal lobe
- neuronal loss and gilosis, ballooned tumors
Parkinson’s disease
chronic and progressive disorder of the CNS, it is a motor disorder
direct loss of cells In the substantial nigra
these cells produce dopamine, loss of dopamine can cause the neuron’s in the brain to fire out of control, so the person can not control their movement
most cases are idiopathic and caused by Brian trauma/ viral inflammation/ poisoning by manganese/ intoxication with MPTP
Huntington’s
inherited, faulty gene on chromosome 4 (IT-15) located in exon 1 –> uninterrupted polyglutamine stretch within the N terminus of the Huntington molecule (CAG)
symptoms: uncontrolled jerky movements, disorganised gait, impaired chewing and swallowing
ALS (amyotrophic lateral sclerosis)
neurodegenerative disease of upper and lower motor neurone of Brain and spinal cord
first mutation was discovered in the SOD1 gene on chromosome 21
giolomas and astrocytoma
gliomas: tumors of the Brain parenchyma
main types of gliomas:
Astrocytomas – resemble astrocytes
Oligodendrogliomas – resemble oligodendrocytes
Ependymomas – resemble ependymal cells
Astrocytomas are tumors that arise from astrocytes, a type of glial cell in the brain.
There are several types, each with distinct histologic features, locations, and clinical behavior.
adult primary brain tumors
1) Glioblastoma is the most aggressive and most common type of primary malignant brain tumor in adults. commonly occurs in the cerebral hemispheres (especially frontal and temporal lobes) Can cross the corpus callosum, producing a classic “butterfly glioma” appearance on imaging
2) Oligodendrogliomas are primary brain tumors that arise from oligodendrocytes, the cells responsible for producing myelin in the central nervous system.commonly found in the cerebral hemispheres, especially the frontal lobes
3) Meningiomas are typically benign, slow-growing tumors that arise from the meninges, specifically the arachnoid cap cells of the dura mater.
4) Hemangioblastomas are rare, benign vascular tumors of the central nervous system, arising from blood vessel-forming cells (endothelial precursors or stromal cells). Most commonly in the cerebellum
Also found in the brainstem, spinal cord, and sometimes retina
5) pituitary adenoma can be silent or hyper functioning, primary adenoma generally refers to a benign tumor that arises from glandular epithelial tissue.
childhood brain tumours
- pilocytic astrocytoma: found in posterior fossa, benign, sciatic appearance with mural nodule
- medullloblastoma: common malignant brain tumor involves cerebellum and can compress the 4th ventricle causing hydrocephalus
- ependymoma: found in the 4th ventricle can cause hydrocephalus
- craniopharyngioma: classification is common, associated with high recurrence rate
- pineal gland tumors: more common in males, parinaud syndrome
- primary CNS lymphoma
- primary brain germ cell tumors
- meningiomas
- diffuse large B cell lymphoma and is associated with EBV and can occur anywhere in the CNS esp periventricular
- occurs along the midline in the pineal region or the supra cellar region
- usually benign, from arachnid meningothelial cells
what is conjunctivitis
Conjunctivitis (Pink Eye)
Definition: Inflammation of the conjunctiva (the membrane covering the white of the eye and inner eyelid)
Can be acute or chronic
Causes:
Most commonly viral or bacterial
Includes gonococcal and chlamydial infections
Transmission:
Spread by direct contact, such as:
Fingers
Towels
Handkerchiefs
Can spread to the other eye or to other people
red eye
without vision loss: allergic, bacterial and viral conjunctivitis
with vision loss: acute anterior uveitis, acute angle closure glaucoma, corneal ulcer
signsL severe eye pain, severe photophobia, reduced visual activity,
