Status epilepticus and coma: absence of clinical signs did not exclude status.

Clinical bottom line (level 4)

  1. Patients in a coma may display no clinical signs of status epilepticus.
  2. Patients in a coma who had rhythmic clonic movements were at increased risk of having status epilepticus.
Lowenstein and Aminoff: Neurology 1992; 42: 100-104
Expires November 2003

The study

Setting: university hospital, USA

47 patients (aged range 16 to 82 years; median 55, 53% male) in a coma (36% following a cardiorespiratory arrest; 25% from infection, 20% from metabolic causes) suspected of having status epilepticus

Excluded if
  • <15 years old
  • phenobarbital iv given before EEG recording



    • Independent blinded reference standard, applied in all patients from a consecutive inappropriate spectrum.
    Reference standard:
    • EEG for 20 minutes: positive if spike-and -wave activity with abrupt onset and termination
    Diagnostic test: clinical features: rhythmic clonic movements (typically involving the extremities, eyes or mouth) for = 30 minutes

    The evidence


    diagnostic test status epilepticus no status epilepticus LR+
    (95% CI)    		 LR-
    (95% CI)
    clinical seizure 33 9 0.87
    (0.77 to 0.98)     		infinity
    (0.53 to infinity)
    total 38 9

    • sensitivity: 86%
    • 55% of patients died - all as a consequence of the underlying disorder.

    Comments

    1. As the spectrum of patients was inappropriate, having no clinical seizure cannot necessarily rule out status epilepticus.
    2. Because of the low patient number and inappropriate spectrum, the results should be viewed with great caution.

    Citation

    1. Lowenstein DH, and Aminoff MJ: Clinical and EEG feature of status epilepticus in comatose patients. Neurology 1992; 42: 100-104
    Contributor: Chris Ball and Clare Wotton, November 2000
    Reviewer:

    Clinical Question.
    Patient suspected status epilepticus
    Intervention or Exposure clinical features
    Outcome diagnosis