Neuropathology

Question 1

Cerebrospinal fluid

Answer 1

Normal volume 150ml

Production by choroid plexus in the lateral ventricles

Reabsorption by arachnoid granulations in subarachnoid space

Metabolic importance

Cushioning of the CNS

Role in immune regulation and defense

Cerebral autoregulation of blood flow

Question 2

Hydrocephalus

Answer 2

Obstruction to CSF flow

Impaired reabsorption at arachnoid granulations

Shrinking of brain tissue

Very rarely overproduction

Communicating
Non- communicating

Question 3

Raised intracranial pressure

Answer 3

Mean CSF pressure above 200mm H2O

Increased CSF volume

Intracranial space occupying lesion (neoplasm, haemorrhage, abscess)

Cerebral oedema

Question 4

Consequences- herniation

Answer 4

Subfalcial
Central/ transtentorial
Tonsillar/ cerebellar

Tonsillar/ cerebellar herniation may cause compression of the medulla with impairment of vital respiratory and cardiac functions

Question 5

Tonsillar herniation at autopsy

Answer 5

Coning herniation and compression of the medulla oblongata

Duret haemorrhages

Question 6

Space occupying lesions

Answer 6

Extradural/ epidural haemorrhage
Subdural haemorrhage
Subarachnoid haemorrhage
Intracerebral haemorrhage

Ischaemic infarct with subsequent oedema or haemorrhage

Neoplasm
Abscess

Question 7

Head trauma

Answer 7

Skull fracture

Parenchymal injury: contusion (bruising), laceration (penetration or tearing), diffuse axonal injury

Coup and contrcoup

Question 8

Vascular injury

Answer 8

Extradural: severe trauma with arterial laceration

Subdural: trauma may be minor in atrophy

Subarachnoid: rupture of saccular enurysm

Intraparenchymal

Question 9

Cerebral oedema

Answer 9

Vasogenic: increased vascular permeability

Cytotoxic: neuronal, glial or endothelial cell damage

Question 10

Cerebral infarction/ stroke

Answer 10

15% cardiac output

20% of O2 demand

Neurones are the most O2 sensitive cells

Haemorrhagic infacrtion in emboli

Ischaemic infarction in thrombosis

Question 11

Ischaemic infarct histology

Answer 11

Acute neuronal injury

‘Red neurones’

Pyknosis of nucleus

Shrinkage of cell bodies

Loss of nucleoli

Intense eosinophilia of cytoplasm

Question 12

Neoplasms

Answer 12

Approx 75% primary (hense 25% metatastic)

20% malignant childhoof tumours located in CNS

Question 13

Types of neoplasms

Answer 13

Gliomas (astrocytoma, oligodendroglioma, glioblastoma)

Neuronal tumours (ganglion cell tumours)

Meningiomas

Poorly differentiated neoplasms (medulloblastoma)

Primary CNS lymphoma

Metastasis (lung, breast, skin, kidney, GI tract)

Peripheral nerve tumours (scwanoma, neurofibroma, MPNST)

Question 14

Meningitis

Answer 14

Bacterial (acute or chronic)

Viral

Fungal

RMSV, neurosyphilis, lyme disease, malaria

Question 15

Abscess

Answer 15

Usually bacterial

Question 16

Encephalitis

Answer 16

Viral (HSV, CMV, HIV, JC, polyoma virus)

Question 17

Localised infection

Answer 17

Toxoplasmosis

Cysticercosis

Question 18

Progressive/ degenerative conditions

Answer 18

Neurodegenerative diseases (Alzheimer’s, Parkinson’s)

Spinocerebellar degenerative disease

Demyelinating diseases (multiple sclerosis)

Prion diseases (Creutzfeldt-Jakob disease)

Genetic metabolic diseases (neuronal storage diseases)

Toxic and acquired metabolic diseases (Vit B1/ 12 def, CO toxicity, alcohol, toxicity, radiation toxicity)

Question 19

Spinocerebellar degenerative disease

Answer 19

Accumulation of protein aggregates leading to loss of cellular and subsequent loss of CNS functions

Dementia, behavioural and personality changes, language disturbance, movement and coordination disturbance, paraylsis