Transitory cognitive impairment with brief generalized spike-wave paroxysm: a clinical counterexample to the three-second rule.

The topic of transitory impairment of consciousness with spike wave bursts has been of interest to neurologists for years. Based on some early experiments, a 3-second rule was formulated and has found its way into the conventional wisdom of neurology. It states that, in order to result in impairment of consciousness, a spike-wave burst must be of at least 3 seconds' duration. We discuss a case which poses a clinical counterexample to that rule.