NEURO: Primary Brain tumours, Meningitis, Encephalitis and Zoster Hepres Flashcards
What are primary tumours
Tumour growing at the anatomical site where tumour progression began + proceeded to form a cancerous mass
What is the telencephalon
Cerebral hemispheres
What is the mesencephalon
Midbrain
Role of glial cells
Maintain homeostasis
Support and protection for neurones
Form myelin
Name 4 glial cells
- Oligodendrocytes
- Astrocytes
- Ependymal cells
- Microglial
Role of astrocytes
Form BBB
Role of microglia
Resident macrophages of CNS
What are glial cell carcinomas called
Gliomas - malignant by the time they are diagnosed
Role of the pineal gland
Produces Melatonin which modulates sleep patterns
Name 4 primary tumours of the brain
Anaplasia
Atypic
Neoplasia
Necrosis
What is anaplasia
Loss of DIFFERENTIATED cells
Total loss of control over normal function
How do cells become anaplastic
Neoplastic tumour cells dedifferentiate to become anapaestic
Cancer stem cells over multiply (uncontrolled growth due to failure of differentiation)
What is Atypia
Cancer cells with structural abnormalities
What is neoplasia
Uncontrolled division of cells
How do neoplasms effect the brain
Grow in confined spaces increasing ICP and invading into the brain as they grow in small spaces - compression of brain structure
Consequences of neoplastic growth
ICP
Destruction of brain parenchyma
In what patients are primary brain tumours common
- Paediatric cancer
What are the main types of gliomas
- Astrocytoma (MOST COMMON PRIMARY BRAIN TUMOUR)
2. Oligodendroglioma
Risk factors for primary brain tumours
- Ionising radiation
- Vinyl Chloride
- Immunosuppreison
- Family History - Genetics
Name Grade I astrocytoma
- Pilocytic astrocytoma
2. Subependymoma
`characteristics of grade I astrocytomas
- Slow growing tumours where total remission is achieved by removal (stereotactic surgery)
Characteristic of grade II astrocytomas
Slow growing benign to malignant tumours
Invasive gliomas that penetrate into surrounding brain (CAN’T be surgically removed)
Name a grade II astrocytoma
- Fibrillary astrocytoma
Clinical presentation of grade II astrocytoma
- SEIZURES
Name a grade III astrocytoma
Anapaestic astrocytoma
Characteristics of grade III astrocytomas
Astrocytes lack vascular proliferation and necrose (These are undifferentiated gliomas)
MALIGNANT
How are grade III astrocytomas
- Radiotherapy
Name a grade IV astrocytomas
Glioblastoma multiform
Characteristics of grade IV astrocytomas
MALIGNANT tumours
Grow quickly and spread to other parts of the brain
So infiltrative no surgical removal of tumour impossible + RADIOTHERAPY doesn’t work
Necrosis
Symptoms of grade IV astrocytomas
BEGIN abruptly with seizures
What do all gliomas progress to at end-stage cancer
Glioblastoma Multiforme (EXCEPT pilocytic astrocytoma)
Clinical presentation of brain gliomas
- Headaches
- Vomiting
- Seizures
- Cranial nerve disorders
- PAPILLOEDEMA
——-INCREASED ICP symptoms——
Clinical presentation of spinal cord gliomas
- Pain
- Weakness
- Numbness
How do gliomas metastasise
Spread via the CSF
What causes malignant gliomas
(50-60)
- Initial genetic error in glucose glycolysis
- Mutation of ISOTRATE DEHYDROGENASE
- Excess build up of 2-hydroxyglutarate
This triggers instability in glial cells and oevrmitosis
OR (older)
CATASTROPHIC GENETIC MUTATION which is sporadic
Clinical presentation of oligodendromas
- Seizures of the frontal lobe
- Increased ICP symptoms
- Visual loss, motor weakness and cognitive decline
What grade cancer are oligodendromas
II
What causes oligodendromas
IDH-1 mutation
In what dura layer are meningiomas made
Arachnoid mater: push into brain but are usually benign
What are neurofibromas
Solid benign tumours form Shwann cells
Where are neurofibromas found
Cerebellopontine angle
What are craniopharyngiomas
Brian tumour from pituitary gland embryonic tissues
Where are craniopharyngiomas common
Children
Are crnaiopharyngiomas benign or malignant
Benign
If Primary brian tumours are benign how can they cause damage
Act as SPACE OCCUPYING LESIONS which increase ICP
Why is there no symptoms when tumour is small
Initially brain removes CSF from ventricles and spinal cord to offset increase in ICP
How does ICP affect brian structures
Midline structure shift and herniation through foramen magnum = brain damage
Symptoms of ICP associated headaches
- WORSE on waking in the morning (we don’t pee at night so accumulation of fluid = ICP)
- Pain can be so bad it can wake patient up
- Pain increased by coughing, straining and bending forwards (increased venous pressure in brain)
- Relieved by vomiting (reduces fluid levels)
Is papilloedema bilateral or unilateral
BILATERAL
What causes papilloedema
Increased ICP
Resp failure!
Guillain-Barre syndrome due to increased protein levels
Tumours of frontal lobe
What is papilloedema
Optic disc swelling
Clinical presentation papilloedema
- Venous engorgement
- Haemorrhages over optic disc
- Blurring of optic margins
- Enlarged blind spot on examination
Pathophysiology of papilloedema
Optic nerve sheath is continuous with subarachnoid space of the brain so increased ICP is transmitted through this sheath
how long does it take for papiloedema to present
DAYS
Clinical presentation of tumours affecting different parts of the brain
Temporal - Dysphagia, amnesia Forntal: Hemiparesis, personality change, brook's dysphagia, lack of initiative, unable to plan tasks Parietal lobe: Hemisensory loss, reduction in 2-point discrimination, dysphagia, astereognosis (unable to recognise object from touch alone) Occipital: Contralateral visual defects Cerebellum: DASHING D - Dysdiadochokinesis A - Ataxia S - Slurred speech (dysarthria) Hypotonia Intention tremor Nystagmus Gait abnormality
What seizures are common with brian tumours
PARTIAL or FOCAL
Differential Diagnosis of primary brain tumours
- Aneurysm
- Abscess
- Cyst
- haemorrhage
- Idiopathic intracranial hypertension
Diagnostic of primary brain tumours
- EEG
- MRI and CT (looks at disruption of BBB)
- FBC
- BIOPSY