Utility of EEG in differential diagnosis of adults with unexplained acute alteration of mental status.

EEG is a safe, inexpensive, mobile test that can be integrated with the neurologic clinical examination and other testing to help physicians move more quickly and accurately to the right branch of the differential diagnostic tree even when the EEG result is not specifically diagnostic itself As technology evolves to allow faster; easier electrode application and remote transmission of EEG data to electroencephalographers; the use of EEG in the emergency room and intensive care units to assist with differential diagnosis is likely to sharply increase. We examine some differential diagnostic scenarios and actual cases where EEG proved useful. Neurologists are trained to think in differential diagnostic terms. As they review EEG tracings, they often ask neurodiagnostic technologists questions pertaining to the patient history or other testing results that help them assimilate the relevant differential diagnostic data. Neurodiagnostic technologists have a unique opportunity to collect useful differential diagnostic information because they spend about 20 minutes talking with the patient as they apply electrodes and they see the EEG results while the patient, family members, or the patient's nurse is still available for questioning. Those technologists who are able to see the bigger picture and think in differential diagnostic terms as they do EEG testing are more likely to include in their patient's history important clinical details that will help the neurologist reach the correct diagnosis of the patient.