How often is EEG used as part of routine dementia evaluation in community practice?

Background Recommendations for evaluation of patients with dementia have changed little in the last thirty years. The guideline for diagnosis of dementia published by the American Academy of Neurology (AAN) in 1984 recommended against routine use of EEG for evaluation of dementia, and in the updated guideline from 2001 EEG is not specifically mentioned. Some authors continue to argue for use of EEG in dementia research, though mostly this focuses on specialized EEG techniques like quantitative EEG. There are few reports, however, on the frequency of EEG use in community neurological evaluations for dementia. Method All new patient referrals to the Novant Health Memory Clinic in Charlotte, NC, for 2020 were reviewed. Information was tabulated for those patients who had been previously evaluated by a neurologist in the community, specifically to determine how often EEG was included as part of the routine evaluation. Results of the EEG as taken from the clinician’s report were tabulated, though there was no opportunity to examined the EEG tracing itself. The author made a judgement as to whether the results of the EEG affected the clinical diagnosis or provided useful information for management of the patient in each case, and these data were tabulated. Result During the year of observation, there were a total of 845 new patient evaluations in the Memory Clinic. Of those, 274 patients met clinical criteria for “Probable” Alzheimer Disease, 237 met criteria for Mild Cognitive Impairment, and 207 for Subjective Cognitive Decline. Out of these patients, 89 had been previously evaluated by a community neurologist. In 63 of the evaluations, EEG was obtained as part of the routine evaluation. Of these, 16 were read as “normal,” and 47 were read as “abnormal” due to slowing of background rhythm. In 2 of the 47, the reader also reported finding “sharp waves” in temporal leads, and these 2 patients were treated by the reading neurologist with anticonvulsants, later discontinued in both cases. In no case did the EEG provide useful information for either diagnosis of management of dementia. Conclusion These data support the AAN guideline’s recommendation against routine use of EEG for dementia evaluation.