Question 9

You have been asked to see a 52-year-old female in the Emergency Department who presented with a fever of 39.5ºC and generalised tonic-clonic seizures. Apart from a persistent reduced level of consciousness, her vital signs are currently stable.

a)    List three central nervous system (CNS) and three non-CNS aetiological classifications for her presentation, with an example of each.    (30% marks)

b)    List six findings on physical examination that would be important in differentiating between potential diagnoses.    (30% marks)

c)    Describe the specific laboratory tests/investigations you would perform or request in this patient with justification for your inclusions.    (40% marks)

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College answer

Not available.


This patient with seizures and a persistently decreased level of consciousness has status epilepticus by the standard definition (where you fail to recover your level of consciousness within a reasonable timeframe). 

a) Three CNS "aetiological classifications" (or could we just call them "causes"):

  • Infectious causes (Meningitis/encephalitis. brain abscess)
  • Autoimmune causes (eg. CNS vasculitis)
  • Subarachnoid haemorrhage

Three extracranial reasons for fever and decreased level of consciousness:

  • Infectious causes (eg. septic encephalopathy)
  • Autoimmune causes (eg. TTP/HUS)
  • Drugs (serotonin syndrome, drug withdrawal, NMS)

b) Six findings on physical examination:

  • Petechii (TTP, meningococcal meningitis, DIC of sepsis)
  • Meningism (meningitis, SAH)
  • Focal neurological signs (brain abscess)
  • Dilated pupils (serotonin syndrome, drug withdrawal)
  • Anuria (TTP/HUS)
  • Evidence of IV drug use (brain abscess, drug withdrawal, serotonin syndrome)

c) Investigations: 

  • LP (meningitis, encephalitis)
  • CK (?rhabdomyolysis)
  • Urine drug screen
  • Blood cultures and inflammatory markers (sepsis, DIC)

One could also include:

  • MRI/MRA (limbic encephalitis, cerebral vasculitis)
  • CT brain (brain abscess, SAG)
  • EEG (ongoing seizures?)

But- as one of the readers has pointed out - a typical examiner's response may be that "some candidates either listed investigations without a description, or included investigations that aren't sent to a laboratory, and scored zero marks." 


Oh's Intensive Care manual:

Chapter 49   (pp. 549) Disorders  of  consciousness  by Balasubramanian  Venkatesh

Chapter   50   (pp. 560) Status  epilepticus  by Helen  I  Opdam

Tan, R. Y. L., A. Neligan, and S. D. Shorvon. "The uncommon causes of status epilepticus: a systematic review." Epilepsy research 91.2 (2010): 111-122.

Johnson, Nicholas, et al. "Anti-NMDA receptor encephalitis causing prolonged nonconvulsive status epilepticus." Neurology 75.16 (2010): 1480-1482.

Chen, James WY, and Claude G. Wasterlain. "Status epilepticus: pathophysiology and management in adults." The Lancet Neurology 5.3 (2006): 246-256.