Brain Tumours Flashcards
(94 cards)
What is a tumour?
Swelling of a tissue
Classifications of brain tumours?
Benign OR malignant
Primary OR secondary
Supratentorial OR infratentorial
Extrinsic (AKA extra-axial) OR intrinsic (AKA intra-axial)
Most common extra-axial tumour?
Meningioma - tumours that arise from residual mesenchymal cells in the meninges; usually benign
NOTE - rarely malignant or invade brain
Produce neurological symptoms by compressing the brain
Other extra-axial tumours?
Pituitary tumours, e.g: adenoma
Cranipharyngioma
Choroid plexus papilloma
Acoustic neuroma (AKA vestibular schwannoma)
Occurence of primary brain tumours?
2nd most common tumour in children (after leukaemia)
Most common cause of cancer death <40 years
Presentation of brain tumours?
Progressive neurological deficit (main presenting feature)
Usually motor weakness
Headache
Seizures
Why are brain tumours not necessarily considered benign?
Contribute to increased mass and ICP within the rigid skull
Can also cause issues by:
• Blocking CSF flow, leading to hydrocephalus
• Haemorrhage
• Midline shift and herniations
Symptoms of raised ICP?
Headaches
Vomiting
Mental changes
Seizures
Types of brain herniations?
Subfalcine herniation (most common cerebral herniation pattern) - characterised by displacement of the brain, typically cingulate gyrus, beneath the free edge of the falx cerebri
Central herniation -
diencephalon and parts of the temporal lobes (of both cerebral hemispheres) are squeezed through a notch in the tentorium cerebelli
Uncal transtentorial herniation - a type of transtentorial herniation that occurs downwards
Tonsillar herniation - characterised by inferior descent, of the cerebellar tonsils, below the foramen magnum
Signs of uncal herniation?
Compression of CN III causes IPSILATERAL, DILATED PUPIL (parasympathetics are affected)
NOTE - this is a pre-terminal sign (patient is close to death)
Causes of headaches?
May occur with or without raised ICP, i.e: there are many causes
Characteristics of headaches due to brain tumours?
Worse in the morning (A HEADACHE THEY WAKE UP)
Headache increases with coughing / leaning forward
May be assoc. and increase in severity with vomiting
OR
Patient may have symptoms similar to tension headache / migraine (difficult to diagnose as a brain tumour)
Examination that must be done with headaches?
Fundoscopy (looking for papilloedema as a sign of raised ICP)
How can brain tumours cause headache?
- Raised ICP
- Invasion / compression of dura, blood vessels, periosteum
- Secondary to diplopia (CN III, IV, VI); CN VI (false localising sign of raised ICP; they need a scan)
- Secondary to difficulty focusing
- Extreme hypertension (Cushing’s triad)
- Psychogenic (stress of loss of functional capacity)
What is the Cushing’s triad?
Cushing’s reflex is a physiological NS response to raised ICP; it results in the Cushing’s triad:
- Increased BP
- Irregular breathing
- Bradycardia
NOTE - this is another pre-terminal event
In situations that are pre-terminal, what should be done about raised ICP?
Administer mannitol (osmotic diuretic); this works for ~20 mins, before body compensates
Organise emergency surgery
Define perseveration?
Repetition of a particular response (such as a word, phrase, or gesture) despite the absence or cessation of a stimulus
It is usually caused by a brain injury
E.g: tapping a patient at the unibrow and they continue to blink after the 1st tap (should stop blinking after the 1st), AKA Glabellar tap test
Define dyspraxia?
……….
Responsibilities of the frontal lobe?
Though, reasoning, behaviour and memory
Region for smell
Motor cortex (movement) in pre-central gyrus, anterior to the central sulcus
Responsibilities of the parietal lobe?
Intellect, thought, reasoning, memory
Region for hearing
Somatosensory cortex (sensation) in post-central gyrus, posterior to the central sulcus
Responsibilities of the occipital lobe?
Right - abstract concepts
Left - speech, motor and sensory functions
NOTE - this is for right-handed individuals
Region for vision
Responsibilities of the temporal lobe?
Behaviour
Memory
Hearing and vision pathways
Emotion
Mnemonic for symptoms and signs that arise due to cerebrellar issues?
D - dysdiadochokinesis A - ataxia N - nystagmus I - intention tremor S - scanning dysarthria H - heel-shin test +ve
Indications that there should be urgent suspicion of cancer referral?
Focal neurological deficit - progressive deficit, inc. personality or behavioural change ((absence of previously diagnosed / suspected alternative disorders)
Change in behaviour - progressive deterioation in cognitive, psychological, behvioural and higher executive functions (absence of previously diagnosed / suspected alternative disorders)
Seizure
Headache - patients with this, vomiting and / or papilloedema
