T1 L17 Neuropathology Flashcards
What is the normal volume of CSF?
150ml
What produces CSF?
Choroid plexus in the lateral ventricles
What are choroid plexuses?
Consist of modified ependymal cells
How much CSF is produced in 24h?
450ml
What are the roles of CSF?
Metabolic importance
Cushioning of CNS
Role in immune regulation & defence
Cerebral auto regulation of blood flow
What causes hydrocephalus?
Obstruction of CSF flow Impaired resorption at arachnoid granulations Shrinking of brain tissue Very rarely an overproduction of CSF Communicating Non-communicating
What is hydrocephalus?
Accumulation of CSF in the brain
What is ex vacuo?
Enlargement of cerebral ventricles & subarachnoid spaces due to shrinkage of brain tissue
What is the consequence of hydrocephalus occurring before fusion of the cranial sutures?
Enlargement of the head circumference
What is the the definition of raised intracranial pressure?
Mean CSF pressure above 200mm H2O
What can cause raised intracranial pressure?
Increased CSF volume (hydrocephalus)
Intracranial space occupying lesion (neoplasm, haemorrhage, abscess)
Cerebral oedema
What is a consequence of raised intracranial pressure?
Herniation
What are some types of herniation caused by raised intracranial pressure?
Subfalcial (cingulate)
Central / transtentorial
Tonsillar cerebellar
Why is tonsillar / cerebellar herniation the most dangerous?
May cause compression of the medulla which impairs the vital respiratory & cardiac functions
What does tonsillar herniation look like at autopsy?
Coning herniation & compression of medulla oblongata
Duret haemorrhages
What are some types of a space occupying lesion?
Extradural / epidural haemorrhage Subdural haemorrhage Subarachnoid haemorrhage Intracerebral haemorrhage Ischaemic infarct with subsequent oedema or haemorrhage Neoplasm Abscess
What are the consequences of head trauma?
Skull fracture
Parenchymal injury - contusion, laceration, diffuse axonal injury
Coup & contrecoup
Vascular injury
What can cause an extradural vascular injury?
Severe trauma with arterial laceration
What is the main cause of a subarachnoid vascular injury?
Rupture of saccular (berry) aneurysm in the circle of willis
What is the main cause of an intraparenchymal vascular injury?
Hypertension
Where is the most common place for a berry aneurysm in the circle of willis?
On the anterior cerebral artery
Where is the least common place for a berry aneurysm in the circle of willis?
The basilar artery
Where on the circle of Willis do 20% of berry aneurysms occur?
On the internal carotid artery
Where on the circle of Willis do 34% of berry aneurysms occur?
In the middle cerebral artery
What are the consequences of a C4 or above injury?
Paralysis of the diaphragm
What is the consequence of a cervical injury?
Quadriplegia
What is the consequence of a thoracic injury?
Paraplegia
What are the 2 types of cerebral oedema?
Vasogenic - increased vascular permeability
Cytotoxic - neuronal, glial or endothelial cell damage
How much of the cardiac output does the brain require?
15%
How much of the oxygen demand does the brain require?
20%
What are the most oxygen sensitive cells?
Neurons
Describe the histology of an ischaemic infarct
Acute neuronal injury Red neurons Pyknosis of nucleus Shrinkage of cell body Loss of nucleoli Intense eosinophilia of cytoplasm
What percentage of neoplasms are primary or secondary?
75% primary
25% secondary
What percentage of malignant childhood tumours are located in the CNS?
20%
Give examples of types of neoplasms
Gliomas Neural tumours Meningiomas Poorly differentiated neoplasms Primary CNS lymphoma Metastasis Peripheral nerve tumours
Where may neoplasms have metastasised from?
Lung Breast Skin / melanoma Kidney GI tract
Give some examples of peripheral nerve tumours
Schwanoma
Neurofibroma
MPNST
Give an example of a poorly differentiated neoplasm
Medulloblastoma
Give some examples of gliomas
Astrocytoma
Oligodendroglioma
Glioblastoma
Give an example of a neural tumour?
Ganglion cell tumours
What are the 4 types of infections?
Meningitis
Abscess
Encephalitis
Localised
What are the types of meningitis?
Bacterial - acute or chronic
Viral
Fungal
RMSV, neurosyphilis, Lyme disease, malaria
What are some examples of viral encephalitis?
HSV
CMV
HIV
JC polyoma virus
Give some examples of localised infections
Toxoplasmosis
Cysticercosis
What are some progressive / degenerative conditions
Neurodegenerative diseases Spinocerebellar degenerative diseases Demyelinating diseases Prion diseases Genetic metabolic diseases Toxic & acquired metabolic diseases
Give some examples of neurodegenerative diseases
Alzheimer’s disease
Parkinson’s disease
Describe the process of spinocerebellar degenerative diseases
Accumulation of protein aggregates –> loss of cellular & subsequent loss of CNS functions
What symptoms do spinocerebellar degenerative diseases cause?
Dementia Behavioural & personality changes Language disturbance Movement & coordination disturbance Paralysis
Give an example of a demyelinating disease
Multiple sclerosis
Give an example of a prion disease
Creutzfeldt-Jakob disease
Give an example of a genetic metabolic disease
Neuronal storage disease
Give examples of toxic & acquired metabolic diseases
Vitamin B1 & B12 deficiency
CO toxicity
Alcohol toxicity
Radiation toxicity
