Neuropathology Flashcards
Give 3 mechanisms that infections can enter the CNS
Direct-spread eg. through middle ear
Blood-bourne eg. sepsis
Iatrogenic eg. lumbar puncture
What is meningitis?
Inflammation of the pia mater and arachnoid mater
What is the main causative organism of meningitis in neonates?
E. coli
L. monocytogenes
What is the main causative organism of meningitis in 2-5 years old?
H. influenzae
What is the main causative organism of meningitis in 5-30 years old?
N. meningitidis
What is the main causative organism of meningitis in >30 years old?
S. pneumoniae
What is the causative organism in chronic meningitis?
Mycobacterium tuberculosis
What are some complications of meningitis?
Cerebral infarction, epilepsy, cerebral abscess, death
What is encephalitis?
(Viral) Infection of the brain parenchyma
Which virus commonly affects the spinal cord in encephalitis?
Polio
Which virus commonly affects the temporal lobe in encephalitis?
Herpes
Which virus commonly affects the brain stem in encephalitis?
Rabies
Who is at risk of cytomegalovirus?
HIV sufferers
What are prions?
Normal molecules found in a synapse
How can prions cause neurological disease?
Mutate and misfold to aggregate and cause neuronal death
What is Variant Creutzfeld-Jacob Disease?
Ingested meat causing unique mutations in prions leading to disease
What is dementia?
Acquired, global impairment of interllect, reason and personality without impairment of consciousness
What is a neurofibrillary tangle?
Intracellular twisted filaments of tau proteins
What is a senile plaque?
Misfolded amyloid protein aggregates
What is the normal intracranial pressure?
0-10mmHg
Why is an expanding lesion in the brain an increasing problem?
Brain can be shifted causing herniation
What is a subfalcine herniation?
The cingulate gyrus is pushed under the falx cerebri
What can a subfalcine herniation result in?
Ischaemia of the medial parts of the frontal and parietal lobes and corpus callosum due to compression of the anterior cerebral artery
What is a tentorial herniation?
Uncus moves through the tentorial notch
What can a tentorial herniation result in?
Oculomotor nerve damage
Occlusion of the posterior cerebral artery
Secondary haemorrhage into the brainstem
What is a tonsillar herniation?
Cerebellar tonsils pushed into the foramen magnum which compresses the brainstem
Why are brain tumours rare?
Cells do not divide quickly
Give an example of a benign brain tumour
Meningioma
Give an example of a malignant brain tumour
Astrocytoma
Give 3 risk factors for a cerebral stroke
Hyperlipidaemia
Hypertension
Diabetes
What is an intracerebral haemorrhage normally associated with?
Hypertensive damage to blood vessels
What structure ruptures to form a subarachnoid haemorrhage?
Berry anurysms
What is a diagnosing symptom of a subarachnoid haemorrhage?
Thunderclap headache
