Learning objectives

  1. Name 5 causes of raised intracranial pressure.
    • Neoplasms: primary or mets (esp. breast, lung, melanoma)
    • Abscesses: sinusitis, OM, dental, mastoiditis, surgery
    • Haemorrhage: stroke, hypertension, intracranial (subarachnoid haemorrhage, subdural or epidural haematoma)
    • CSF hydrocephalus: blockage of CSF at the aqueduct of Sylvius (cerebral aqueduct) by oedema or blood
    • Infection: encephalitis (e.g. HSV), meningitis (e.g. NM, SP)
    • Others: MS, granuloma, herniation
  2. Describe 5 complications of raised ICP.
    • Respiratory depression: compression of respiratory centres
    • Bradycardia: decreased sympathetic input to heart
    • Decerebrate posture: extension of neck
    • Death: cardio-respiratory arrest
    • Altered consciousness: due to coning (herniation of cerebellar tonsils through foramen magnum)
  3. Describe the clinical Sx of spinal cord compression (5 Sx).
    • Initially localised back pain: exacerbated by movements, worsens when supine
    • Radicular pain: tight band like constrictions over thorax/abdo, radiates down arms/legs
    • Lhermitte's sign: when neck flexed
    • Incontinence: urinary & faecal
    • Motor symptoms: e.g. heavy legs
  4. What causes hypercalcemia in bone metastases?
    • Result of bone destruction!!
    • Tumours cells secretions may stimuate osteoclast activity
  5. Name 4 common viral causes of meningitis.
    • HSV& EBV
    • Mumps
    • Enteroviruses
  6. Name 4 common viral causes of encephalitis.
    • EBV & HSV (same as meningitis)
    • Arbovirus
    • Variecella
  7. Name 3 non-infectious causes of meningeal irritation.
    • Sarcoidosis
    • Subarachnoid haemorrhage
    • Chemical meningitis (intrathecal drugs/contaminants)
  8. Explain the mechanism of headache, neck stiffness, photophobia and N&V in meningitis.
    • Headache: raised ICP
    • Neck stiffness: cervical muscle spasm
    • Photophobia: oedema causes over-stimulation of retinal photoreceptors with electric impulses to optic n.
    • N&V: afferent nerves to the vomiting centre arise from splanchinic and vagal n., vestulo-labyrithine receptor, cerebral cortex and the chemoreceptors trigger zone (which samples CSF)
Card Set
Learning objectives