Using EEG to distinguish DLB from AD
This is an interesting abstract of an article on the use of EEG to distinguish between AD and DLB. The Dutch authors conclude: "The GTE is a simple EEG scoring method that can be helpful in the differential diagnosis between DLB and AD with a good sensitivity and specificity." GTE = Grand Total EEG score. Sensitivity was 72% and specificity was 85% using a GTE cut-off of 9.5.
Journal of Neurology, Neurosurgery, and Psychiatry. 2007 Aug 6; [Epub ahead of print]
The use of EEG in the diagnosis of dementia with Lewy bodies.
Roks G, Korf E, van der Flier W, Scheltens P, Stam C.
Elisabeth hospital, Netherlands.
Although reports on EEG in dementia with Lewy bodies (DLB) are conflicting, the recent diagnostic guidelines define EEG abnormalities as supportive for the diagnosis. We examined EEG abnormalities in 18 DLB patients, 34 Alzheimer's disease (AD) patients and 36 patients with subjective memory complaints (SMC) using the Grand Total EEG (GTE) score. There was a difference in median GTE score of DLB (11.0), AD (4.
, and SMC (2.5) (P<0.001). Patients with DLB had higher scores than patients with AD. ROC analyses revealed that DLB could be distinguished from AD with a sensitivity of 72% and a specificity of 85% at a GTE cut-off of 9.5. The association between GTE and DLB was independent of age, gender, MMSE, and medication use. Frontal intermittent rhythmic delta activity (FIRDA) was found in 2.9% of the AD patients and in 33.3% of the DLB patients. The GTE is a simple EEG scoring method that can be helpful in the differential diagnosis between DLB and AD with a good sensitivity and specificity.
PubMed ID#: 17682010
Though not necessary to understand the abstract, I found this explanation of a ROC analysis helpful:
That webpage includes this: "An ROC curve is a graphical representation of the trade off between the false negative and false positive rates for every possible cut off. Equivalently, the ROC curve is the representation of the tradeoffs between sensitivity (Sn) and specificity (Sp)."