EEG Could Help to Pinpoint Cause of Rapidly Progressive Dementia
Electrical activity in the brain can distinguish between different types of rapid dementia.
Rapidly progressive dementias are neurologic disorders characterized by the development of cognitive impairment within months or even days. They can be caused by a rare, fatal brain disorder called Creutzfeldt-Jakob disease, which is incurable, or a condition called voltage-gated potassium channel complex–associated autoimmune encephalitis (VGKC AE), which is potentially treatable. However, the clinical features and imaging results for these two conditions can mimic each other, and better methods for diagnosing different types of rapidly progressive dementia are needed.
In a study published last month in Clinical EEG and Neuroscience, researchers examined whether electroencephalography (EEG) -- a technique that records electrical activity in the brain using scalp electrodes -- could distinguish between patients with Creutzfeldt-Jakob disease and VGKC AE. The researchers performed a retrospective review of EEG data for 14 patients with Creutzfeldt-Jakob disease and 17 patients with VGKC AE.
The findings suggest that EEG could aid in the diagnosis of different types of rapidly progressive dementia. For instance, generalized suppression of EEG activity as well as periodic EEG discharges were more prevalent in patients with Creutzfeldt-Jakob disease, presumably due to the greater extent of brain injury. However, the agreement between the two EEG raters was only moderate for diagnosing Creutzfeldt-Jakob disease based on EEG patterns, and poor for interpreting generalized suppression of activity.
According to the authors, repeat testing improves the specificity and sensitivity of EEG and should be performed if the diagnosis is still in doubt. Moreover, the findings suggest that a broad approach involving multiple tests should be used to diagnose the cause of rapidly progressive dementia. Future research is needed to better define particular EEG characteristics that distinguish between different types of patients.