Flashcards in Conditions Deck (21)
What are primary headaches?
Refer to disorders with no secondary underlying pathology e.g. migraine
What are secondary headaches?
- Space occupying lesion - increased pressure
- Intracranial hypertension
What is cortical spreading depression?
Initiated by slowly propagated wave of depolarization in neurones and glial cells. This is followed by a sustained suppression of spontaneous neuronal activity.
What conditions does cortical spreading depression occur in?
- Cerebrovascular accident
- Traumatic brain injury
What are some trigger factors for migraines?
- Relaxing after stress
- Menstruation - triggered by oestrogen decline
- Jet-lag - change in sleep pattern
- Cheese - food containing tyramine, red wine, cheese, chocolate, citrus fruits
- Flickering lights on tv screen - bright lights, loud sounds
What are the differentials of meningitis?
- Encephalitis: most common cause is herpes simplex virus (HSV). This is inflammation of the brain and causes confusion, disorientation, drowsiness. seizures, changes in personality and behaviour e.g. agitated.
- Non-infectious causes (blood, trauma, drugs) of meningeal irritation
- Subdural empyema
What are the risk factors for meningitis?
- Extremes of age
- Living in close proximity - outbreaks can occur in student halls and boarding schools
- Vaccination history (absence of)
- Immune suppression/deficiency
Who is most at risk of meningitis?
- Immunocompromised people to infections caused by less common organisms
- Neonates and children under 1 year of age are particularly vulnerable to meningitis, as their BBB is not fully developed
What do you need to ask in a history for meningitis?
Recent travel history as some countries have high rates of pneumococcal penicillin resistance.
e.g. Canada, Greece, Italy, Mexico, Poland, Spain, Turkey, USA
What are the causes of intracranial space occupying lesions?
- Tumours - primary: benign, malignant or secondary
What are the infectious causes of intracranial space occupying lesions?
- Brain abscess
- Subdural empyema
- Granuloma e.g. tuberculosis
What are the vascular causes of intracranial space occupying lesions?
- Extradural haemorrhage - acute/trauma
- Subdural haemorrhage - acute/trauma
- Subarachnoid haemorrhage - spontaneous
- Parenchymal brain haemorrhage - spontaneous
- Caveroma or vascular malformations
- Brain infarction
What are the hydrocephalus causes of intracranial space occupying lesions?
- Non-communicating or obstructive - tumours, cysts, intra-ventricular haemorrhage
- Communicating - meningitis, SAH
- Overproduction (rare) - choroid plexus papilloedema
What is the WHO grading of glioma?
Grade I: pilocytic astrocytoma (least malignant)
Grade II: low grade astrocytoma
Grade III: anaplastic astrocytoma
Grade IV: glioblastoma multiforme (most malignant)
What is meningioma?
- Arises from arachnoid cap cells
- Generally benign
- Trauma, radiation, oncogenic virus and hormones are implicated in their causation but still unclear
What is vestibular schwannoma?
- Benign tumour arising from the nerve sheath of vestibular nerves, typically in CP angle
- Usually presents with ipsilateral hearing problems and tinnitus
- 5th, 7th and lower cranial nerves can be affected
What is the normal and pathological ICP?
Normal - <15mmHg
Pathological - >20mmHg
What influences ICP?
- ICP is lower in children and can be negative in newborns
- Transient elevations occur when coughing/sneezing etc
- Can be negative standing up because of rigid venous sinuses
- Can be influenced by intra-thoracic pressures
What are the causes of raised ICP?
Increase in brain/tissue/mass volume
- Cerebral oedema
- SOL - tumour, haematoma, abscess
Increase in CSF volume
- Obstruction to CSF circulation
- Reduced CSF absorption
- Increased CSF production
Increase in blood volume
- Raised arterial pCO2
- Venous obstruction
- Increased temperature
What is a cluster headache?
Most severe pain ever lasting 30-120mins. Unilateral, side-locked. Agitation, pacing.