Diagnosing brain conditions by quantitative electroencephalography

• US 5,230,346 A
• Filed: 02/04/1992
• Issued: 07/27/1993
• Est. Priority Date: 02/04/1992
• Status: Expired due to Term

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Cook, Ian A., Leuchter, Andrew F.
• Primary Examiner(s): HINDENBURG, MAX F
• Application Number:
  US07/830,676
• Time in Patent Office: 539 Days
• Field of Search: 128/731, 128/732, 128/641, 128/419 R, 128/791
• US Class Current: 600/544
• CPC Class Codes: A61B 5/374 Detecting the frequency distribution of signals, e.g. detecting delta, theta, alpha, beta or gamma waves
• CPC Class Codes: A61B 5/4064 Evaluating the brain A61B5/031, A61B5/369, A61B5/14553 take precedence
• CPC Class Codes: A61B 5/4088 Diagnosing of monitoring cognitive diseases, e.g. Alzheimer, prion diseases or dementia

Abstract

Determining the brain condition of a human between normal and abnormal as determined by dementia, and selectively between dementia of the Alzheimer'"'"'s-type and multi-infarct dementia is effected. Measures of electrical output, spectral ratio and coherence value of the brain are determined. Selected scores are applied to the electrical output, spectral ratio and coherence values. A relationship between the scores and addi-tionally the scored value of a coherence ratio are effected to obtain a diagnostic evaluation.

Claims

1. A method of diagnosing a brain condition in a human comprising applying electrodes from an EEG unit about the head of a human, determining from the electrodes at least one measure of an electrical signal output of a brain region in the head of a subject, determining at least one spectral ratio of a brain region in the head of the subject, determining at lest one coherence value of a brain region, applying a relationship between the electrical signal output, spectral ratio and coherence as a diagnostic evaluation of the brain condition, and presenting such relationship.

2. A method as claimed in claim 1 including determining at least three measures of the electrical signal output of brain regions.

3. A method as claimed in claim 2 including determining at least two spectral ratios of brain regions.

4. A method as claimed in claim 3 including allocating selected scores to each of the electrical signal output, spectral ratios, and coherence and applying a relationship of the scores as the diagnostic evaluation of the brain condition.

5. A method as claimed in claim 4 including allocating selected scores to each of three electrical signal outputs, two spectral ratios and two coherence values, and applying the relationship of the scores as the diagnostic evaluation.

6. A method as claimed in claim 5 wherein the score is related to normal and abnormal brain conditions respectively and wherein the scores are a predetermined number of selected integers, and wherein the highest integer represents an abnormal brain condition, the lowest integer represents a normal brain condition, and middle integers are selected to represent a selected measure of departure from a normal brain condition, and wherein the scores representative of electrical signal output, spectral ratio, and coherence are added to provide a diagnostic evaluation of the brain condition.

7. A method as claimed in claim 2 including allocating selected scores to each of the electrical signal output, spectral ratios, and coherence and applying a relationship of the scores as the diagnostic evaluation of the brain condition.

8. A method as claimed in claim 7 wherein the score is related to normal and abnormal brain conditions respectively and wherein the scores are a predetermined number of selected integers, and wherein the highest integer represents an abnormal brain condition, the lowest integer represents a normal brain condition, and middle integers are selected to represent a selected measure of departure from a normal brain condition, and wherein the scores representative of electrical signal output, spectral ratio, and coherence are added to provide a diagnostic evaluation of the brain condition.

9. A method as claimed in claim 4 wherein the score is related to normal and abnormal brain conditions respectively and wherein the scores are a predetermined number of selected integers, and wherein the highest integer represents an abnormal brain condition, the lowest integer represents a normal brain condition, and middle integers are selected to represent a selected measure of departure from a normal brain condition, and wherein the scores representative of electrical signal output, spectral ratio, and coherence are added to provide a diagnostic evaluation of the brain condition.

10. A method as claimed in claim 1 including determining at least two measures of spectral ratio of brain regions.

11. A method as claimed in claim 3 including allocating selected scores to each of the electrical signal output, spectral ratios, and coherence and applying a relationship of the scores as the diagnostic evaluation of the brain condition.

12. A method as claimed in claim 11 wherein the score is related to normal and abnormal brain conditions respectively and wherein the scores are a predetermined number of selected integers, and wherein the highest integer represents an abnormal brain condition, the lowest integer represents a normal brain condition, and middle integers are selected to represent a selected measure of departure from a normal brain condition, and wherein the scores representative of electrical signal output, spectral ratio, and coherence are added to provide a diagnostic evaluation of the brain condition.

13. A method as claimed in claim 1 including applying a coherence relationship, together with the electrical signal output and spectral ratio as a diagnostic evaluation between a normal condition and a condition of dementia.

14. A method as claimed in claim 13 including allocating selected scores to each of the electrical signal output, spectral ratio and the coherence, and applying the relationship of the scores as the diagnostic evaluation.

15. A method as claimed in claim 13 wherein the score is related to normal and abnormal brain conditions respectively and wherein the scores are a predetermined number of selected integers, and wherein the highest integer represents an abnormal brain condition, the lowest integer represents a normal brain condition, and middle integers are selected to represent a selected measure of departure from a normal brain condition, and wherein the scores representative of electrical signal output, spectral ratio, and coherence are added to provide a diagnostic evaluation of the brain condition.

16. A method as claimed in claim 1 including allocating selected scores to each of the electrical signal output, spectral ratios, and coherence, and applying a relationship of the scores as the diagnostic evaluation of the brain condition.

17. A method of diagnosing a brain condition in the human comprising applying electrodes from an EEG unit about the head of a human, determining from the electrodes at least three measures of electrical signal output of the brain region in the head of the subject, determining at least two spectral ratios of a brain region in the head of a subject, determining at least two coherence values of a brain region in the head of a subject, allocating selected scores to each of the electrical signal outputs, spectral ratios, and the coherence, the scores being selected integers between 0 and 5, and preferably being 0, 1, 2, 3 and 5, and wherein the lowest integer represents a normal brain condition, the highest integer is representative of an abnormal brain condition indicative of dementia, integers 1 to 3 are representative of varying departures from a normal brain condition, adding the scores from the three electrical signal outputs and the scores from the two spectral ratios and the two coherence values as a determination of the measure of normality or dementia of the subject, and presenting such determination.

18. A method of diagnosing a brain condition in the human comprising applying electrodes from an EEG unit about the head of a human, determining at least one measure of coherence between two brain regions in the head of a subject, applying a coherence value as a diagnostic evaluation of the brain condition thereby to facilitate distinguishing between a dementia condition of the Alzheimer'"'"'s-type and a condition of multi-infarct dementia, and presenting such coherence value.

19. A method as claimed in claim 18 including allocating selected scores to the coherence value and applying a relationship of the scores as the diagnostic evaluation of the brain region.

20. A method of diagnosing a brain condition in the human comprising applying electrodes from an EEG unit about the head of a human, determining at least two coherence values of a brain region in the head of the subject, the one coherence value being a coherence value within the posterior cortex, and second coherence value being that between the front and the back of the brain, applying a relationship between the values as a diagnostic evaluation of a brain condition of either dementia of the Alzheimer'"'"'s-type or multi-infarct dementia, and presenting such relationship.

21. A method of diagnosing a brain condition in the human comprising applying electrodes from an EEG unit about the head of a human, determining from the electrodes at least one measure of an electrical signal output of a brain region in the head of a subject, determining at least one spectral ratio of a brain region in the head of a subject, determining at least one coherence value of a brain region in the head of a subject, allocating selected scores to each of the electrical signal output, spectral ratios and coherence values, applying a relationship between the scores and additionally applying a coherence relationship between selected coherence values prior to a further scoring, such selected scores and further scoring being used as a diagnostic evaluation of the brain condition, the evaluation being selectively to distinguish between dementia, nondementia and in the case of dementia, to distinguish between dementia of the Alzheimer'"'"'s-type and multi-infarct dementia, and presenting such relationship.

22. A method of diagnosing the nature of dementia in a human comprising applying electrodes from an EEG unit about the head of a human, determining from the electrodes at least three measures of electrical signal output of a brain region in the head of a subject, the three measures being absolute power from the front of the head, determining at least two spectral ratios of a brain region in the head of a subject, the spectral ratios being at the back of the head, determining at least two coherence values of the brain region in the head of a subject, the one coherence value being that within the posterior cortex and the other coherence value being that between the front and back of the head, allocating selected scores to each of the electrical signal outputs, spectral ratios and selected coherence values, the scores being predetermined values between a low value and a high value, the low value being representative of normal-type conditions, the high value being representative of dementia, and a middle value being representative of intermediate degrees of abnormality, and wherein additionally a condition is distinguishable between dementia of the Alzheimer'"'"'s-type and multi-infarct dementia in accordance with the scored coherence values, and presenting the scores.

23. Apparatus for diagnosing a brain condition comprising electrodes from an EEG unit for location about the head of a human, means for determining from the electrodes at least one measure of an electrical signal output of a brain region in the head of a subject, means for determining at least one spectral ratio of a brain region in the head of the subject, means for determining a coherence value, means for applying a relationship between the electrical signal output, spectral ratio and the coherence value as a diagnostic evaluation of the brain condition, and means for presenting such relationship.

24. Apparatus for diagnosing a brain condition as claimed in claim 23 including means for determining at least three measures of the electrical signal output of the brain region.

25. Apparatus for diagnosing a brain condition as claimed in claim 24 including means for determining at least two spectral ratios of the brain region.

26. Apparatus for diagnosing a brain condition as claimed in claim 23 including means for allocating selected scores to each of the electrical signal output, spectral ratios, and coherence, and means for applying a relationship of the scores as the diagnostic evaluation of the brain condition.

27. Apparatus for diagnosing a brain condition as claimed in claim 26 including means for adding the scores representative of electrical signal output, spectral ratio, and coherence, and selectively including means for additionally adding a score of coherence ratio to provide a diagnostic evaluation of the brain condition.

28. Apparatus for diagnosing a brain condition as claimed in claim 24 including means for allocating selected scores to each of the electrical signal output, spectral ratios, and coherence, and means for applying a relationship of the scores as the diagnostic evaluation of the brain condition.

29. Apparatus for diagnosing a brain condition as claimed in claim 28 including means for adding the scores representative of electrical signal output, spectral ratio, and coherence, and selectively including means for additionally adding a score of a coherence ratio to provide a diagnostic evaluation of the brain condition.

30. Apparatus for diagnosing a brain condition as claimed in claim 23 including means for determining at least two measures of spectral ratio of a brain region.

31. Apparatus for diagnosing a brain condition as claimed in claim 30 including means for allocating selected scores to each of the electrical signal output, spectral ratios, and coherence, and means for applying a relationship of the scores as the diagnostic evaluation of the brain condition.

32. Apparatus for diagnosing a brain condition as claimed in claim 31 including means for adding the scores representative of electrical signal output, spectral ratio, and coherence, and selectively including means for additionally adding a score of a coherence ratio to provide a diagnostic evaluation of the brain condition.

33. Apparatus for diagnosing a brain condition as claimed in claim 23 including means for allocating selected scores to each of the electrical signal output, spectral ratios, and coherence, and means for applying a relationship of the scores as the diagnostic evaluation of the brian condition.

34. Apparatus for diagnosing a brain condition as claimed in claim 33 including means for adding the scores representative of electrical signal output, spectral ratio, and coherence, and selectively including means for additionally adding a score of a coherence ratio to provide a diagnostic evaluation of the brain condition.

35. Apparatus for diagnosing a brain condition in a human comprising electrodes from an EEG unit for locations about the head of a human means for determining from the electrodes at least three measures of electrical signal output of the brain region in the head of the subject, means for determining at least two spectral ratios of a brain region in the head of a subject, means for determining two coherence values, means for allocating selected scores to each of the electrical signal outputs, spectral ratios and a coherence values, the scores being selected integers between 0 and 5, and preferably being 0, 1, 2, 3 and 5, and wherein the lowest integer is representative of a normal brain condition, the highest integer is representative of an abnormal brain condition indicative of dementia, and middle integer scores are representative of varying departures from a normal brain condition, means for adding the scores from the three electrical signal outputs, the scores from the two spectral ratios and the coherence values to determine the measure of normality or dementia of the subject, and means for presenting such scores.

36. Apparatus for diagnosing a brain condition comprising electrodes from an EEG unit for location about the head of a human, means for diagnosing a brain condition in a human comprising means for determining from the electrodes at least two coherence values of a brain region in the head of the subject, the one coherence value being a coherence value within the posterior cortex, and second coherence value being the value between the front and the back of the brain, means for applying a relationship between the values as a diagnostic evaluation of a brain condition of either dementia of the Alzheimer'"'"'s-type or multi-infarct dementia, and means for presenting such relationship.

37. Apparatus for diagnosing a brain condition comprising electrodes from an EEG unit for location about the head of a human, means for diagnosing a brain condition in a human comprising means for determining from the electrodes at least one measure of the electrical signal output of a brain region in the head of a subject, means for determining at least one spectral ratio of a brain region in the head of a subject, means for determining at least two coherence values of a brain region in the head of a subject, means for allocating selected scores to each of the electrical signal output and spectral ratios and a coherence value, means for applying a relationship between the scores and additionally a ratio of coherence values as a diagnostic evaluation of the brain condition, the evaluation being selectively to distinguish between dementia, non-dementia and in the case of dementia, to distinguish between dementia of the Alzheimer'"'"'s-type and multi-infarct dementia, and means for representing such relationship.

38. Apparatus for diagnosing a brain condition comprising electrodes from an EEG unit for location about the head of a human, means for diagnosing the nature of dementia in a human comprising means for determining from the electrodes at least three measures of electrical signal output of a brain region in the head of a subject, the three measures being absolute power from the front of the head, means for determining at least two spectral ratios of a brain region in the head of a subject, the spectral ratios being at the back of the head, means for determining at least two coherence values of the brain region in the head of a subject, the one coherence value being that within the posterior cortex and the other coherence value being that between the front and back of the head, means for allocating and adding selected scores to each of the electrical signal outputs, spectral ratios and coherence values, the scores being predetermined values between a low value and a high value, the low value being representative of normal-type conditions, the high value being representative of dementia, and the middle value being representative of an intermediate degree of abnormality, including means for obtaining a ratio of coherence values and scoring the ratio wherein a determination of dementia is distinguishable between dementia of the Alzheimer'"'"'s-type and multi-infarct dementia in accordance with a scored ratio of coherence values, and means for representing such scores.

39. A method of diagnosing a brain condition in a human comprising applying electrodes from an EEG unit about the head of a human, determining a measure of coherence between two brain regions in the head of a subject and wherein the coherence measure is obtained from averaging coherence data from multiple selected electrode pairs located about the head of the human, applying a coherence value as a diagnostic evaluation of the brain condition thereby to facilitate distinguishing between a dementia condition of the Alzheimer'"'"'s-type and a condition of multi-infarct dementia, and representing such value.

40. A method of diagnosing a brain condition in a human comprising applying electrodes from an EEG unit about the head of a human, determining a measure of coherence between at let two brain regions linked by neuroanatomic tracts in the head of a subject, and wherein the coherence measure is obtained from averaging coherence data from multiple selected electrodes located about the head of a human, applying a coherence value as a diagnostic evaluation of the brain condition, and representing such value.

41. A method as claimed in claim 40 wherein the electrodes are applied as bipolar pairs.

42. A method as claimed in claim 41 wherein the value facilitates distinguishing between conditions with different functional connections related to brain dysfunction of the underlying tracts.

43. A method as claimed in claim 40 wherein the value facilitates distinguishing between conditions with different functional connections related to brain dysfunction of the underlying tracts.

44. A method of diagnosing a brain condition in a human comprising applying electrodes from an EEG unit about the head of a human, determining at least two coherence values of a brain region in the head of the subject, the one coherence value being a coherence value within the posterior cortex, and second coherence value being that between the front and the back of the brain, applying a relationship between the values as a diagnostic evaluation of a brain condition, and presenting such relationship.