CNS Pathology

• Fill in the blanks

  A) Basilar

  B) Vertebral

  C) Anterior inferior cerebellar (AICa)

  D) Posterior inferior cerebellar (PICa)

  E) Superior cerebellar

  F) Posterior cerebral

  G) Posterior communicating

  H) Middle cerebral

  I) Internal carotid

  J) Anterior cerebral

  K) Anterior communicating

  
• What is shown in this CT scan?


  Infarct in L inferior cerebellum (territory of AICA or PICA)

  
• What does the circle of Willis supply?

  Cerebral and cerebellar circulation
• Why is cortical functional anatomy important in diagnosing ischaemic events?

  It helps identify movement (M1, premotor areas), visual loss (visual cortex), and speech issues (Broca's & Wernicke's)
• Which cranial nerves are supplied by the vertebrobasilar system?

  Cranial nerves III to XII
• What are the functions of the cerebellum?

  Cognitive function, proprioception, motor coordination, vestibular function
• What is the role of the cerebrocerebellum?

  Broader cortical function and feedback to frontal cortex
• What is the blood supply to the cerebellum?

  Superior cerebellar artery, anterior and posterior inferior cerebellar arteries
• What does a DWI MRI scan show in stroke?

  Bright signal indicates infarct due to water diffusion issues
• What does the term 'locked-in syndrome' refer to?

  Condition where patient is aware but cannot move

  Motor tracts are ischaemic but dorsal tracts are spared
• What areas are involved in conscious vestibular sensation?

  S1 and vestibulocortical areas in the brain
• What is the significance of Broca's area?

  Associated with language production and speech
• What does damage to the vagus nerve cause?

  Dysphonia or slurred speech
• What is the role of the cerebellum in vestibular function?

  Coordinates balance and spatial orientation
• What does 'occlusion of the left vertebral artery' suggest?

  Potential for brainstem ischemia and stroke
• What can occlusion of the basilar artery lead to?

  Altered consciousness

  Coma

  Locked-in syndrome
• What happens if the motor tracts are ischemic but sensory tracts are spared?

  It can lead to locked-in syndrome
• What is the percentage of strokes that are hemorrhagic?

  Approximately 10%
• What are the consequences of hemorrhagic strokes?

  Raised intracranial pressure and herniation
• What is the function of Protein S?

  Inhibiting thrombosis
• What does a patent foramen ovale (PFO) allow?

  Venous thrombemboli to enter systemic circulation
• What is the typical shape of an epidural hematoma?

  Convex
• What typically causes a subdural hematoma?

  Soft tissue trauma resulting in venous bleed
• What is a common symptom of subarachnoid hemorrhage?

  Thunderclap headache
• What can tonsillar herniation compress?

  The brainstem (pons/medulla)
• What cranial nerve is affected by uncal herniation?

  Oculomotor nerve (CN III)
• What is the area postrema known for?

  Initiating the vomiting reflex

  Compression on this area triggers vomiting
• What are the types of herniation and their causes?

  • Subfalcine: Caused by space-occupying lesion
  • Transtentorial: Caused by large mass (e.g., hemorrhage)
  • Uncal: Impinges on crus cerebri (corticospinal/bulbar tracts) and oculomotor nerve
  • Tonsillar: Pushes cerebellar tonsils into foramen magnum
• What are the consequences of raised intracranial pressure?

  • Can lead to herniation
  • Can cause altered consciousness
  • Can result in coma
• What are the common causes of ischemic stroke?

  • Thrombosis
  • Embolism
  • Hypoperfusion
• What are the key features of a hemorrhagic stroke?

  • Rarer than ischemic strokes
  • Generally worse prognosis
  • Can lead to raised intracranial pressure
• What are the different types of haematomas?

  Epidural -> often associated with the middle meningeal artery

  Subdural

  Sub-arachnoid
• Fill in the blanks

  A) epidural

  B) subdural

  C) subarachnoid

  
• What is the typical shape of a subdural haematoma?

  Concave
• What is the typical cause of an epidural haematoma?

  Skull fracture that perforates meningeal artery
• How do subarachnoid haematomas look on imaging?


  Blood in subarachnoid space & cisterns

  
• Subarachnoid haematomas can be clinically asymptomatic to fatal. Most pts have a thunderclap headache - due to immediate rise in ICP (when result of ruptured aneurysm).
• What is Duret haemorrhage?

  Bleeding in pons in region of corticospinal/bulbar tracts

  Frequently fatal