P300 Evoked Potential May Identify Early Brain Deterioration

DENVER — The P300 evoked-potential component of the EEG may provide a readily accessible early window on cognitive decline well in advance of the irreversible changes leading to dementia.

That’s the working hypothesis of Dr. Eric Braverman, who noted that the P300 is an easy-to-administer test that takes just 10 minutes and is well suited for use as a screening tool for middle-aged patients in primary care physicians’ offices.

"My vision is that we’re all going to have laptop brain-health checkups," he declared at the annual meetingof the American Neuropsychiatric Association.

He drew a parallel between dementia and coronary heart disease: Much as electrophysiological deterioration of the heart (as elicited by an exercise treadmill test) is generally antecedent to the massive metabolic derangement of an MI, he is convinced that electrophysiological deterioration in the brain (as expressed in delayed P300 evoked-potential latency) precedes the hypometabolic changes seen on functional PET imaging.

"The P300 is like a stress test of the head to find early deterioration in the [electrophysiological] parameters of voltage – a marker of overall brain cellular atrophy – and latency, or brain-processing speed," according to Dr. Braverman of Cornell University, New York, who is the founder and director of PATH (Place for Achieving Total Health) Medical.

"Thirty-five years of experience have shown me that a positive metabolic PET scan generally results in my patients’ having deteriorated compliance, deteriorated management, and a deteriorated progression," he said. "I’ve come to realize that the PET scan is really amazingly helpful in seeing patients in mild cognitive impairment states that are very damaged. The issue for me in preventive medicine is, can I predict who’s going to get a bad PET scan, so we can break the process through all the techniques we have, from treating depression to nutritional therapy, hormonal therapy, and lifestyle therapy."

Dr. Braverman presented a study of 85 subjects with mild cognitive impairment who received a comprehensive medical evaluation, including functional FDG [¹⁸fluorodeoxyglucose]–PET imaging, neuropsychological testing, and P300. In all, 44 had hypometabolism on PET and the rest had normal brain metabolism. Both groups had a mean age in the mid-50s.

The key study finding was that the two groups differed significantly in terms of their P300 voltage and latency. The mean P300 latency was 346 ms in the group with hypometabolic PET findings, compared with 323 ms in the normal metabolic group. The mean P300 voltage was 3.25 mV in the hypometabolic group and 5.0 mV in those with normal metabolism on functional PET.

It’s known that P300 latency increases with advancing age at a rate of 7-10 ms per decade. Since the mean difference between the hypometabolic and normal metabolic PET groups was 23 ms, that means that the hypometabolic patients exhibited the slower brain-processing speeds that are more typical of individuals at least 20-30 years older, according to Dr. Braverman.

The next step in his research project will be to try to identify the combination of P300 latency and voltage values and neuropsychological test results that are optimally predictive of which patients with memory and attention complaints are sufficiently early in cognitive decline that they haven’t developed hypometabolism, he added.

Session chair Dr. Jeremy D. Schmahmann indicated that this novel preventive strategy is still far from ready for routine use in clinical practice.

"It’s an interesting beginning, and hopefully we’ll see it progress," commented Dr. Schmahmann, professor of neurology at Harvard Medical School and director of the ataxia unit and the laboratory of neuroanatomy and cerebellar neurobiology at Massachusetts General Hospital, both in Boston.

Dr. Braverman indicated he had no relevant financial interests.

DENVER — The P300 evoked-potential component of the EEG may provide a readily accessible early window on cognitive decline well in advance of the irreversible changes leading to dementia.

That’s the working hypothesis of Dr. Eric Braverman, who noted that the P300 is an easy-to-administer test that takes just 10 minutes and is well suited for use as a screening tool for middle-aged patients in primary care physicians’ offices.

"My vision is that we’re all going to have laptop brain-health checkups," he declared at the annual meetingof the American Neuropsychiatric Association.

He drew a parallel between dementia and coronary heart disease: Much as electrophysiological deterioration of the heart (as elicited by an exercise treadmill test) is generally antecedent to the massive metabolic derangement of an MI, he is convinced that electrophysiological deterioration in the brain (as expressed in delayed P300 evoked-potential latency) precedes the hypometabolic changes seen on functional PET imaging.

"The P300 is like a stress test of the head to find early deterioration in the [electrophysiological] parameters of voltage – a marker of overall brain cellular atrophy – and latency, or brain-processing speed," according to Dr. Braverman of Cornell University, New York, who is the founder and director of PATH (Place for Achieving Total Health) Medical.

"Thirty-five years of experience have shown me that a positive metabolic PET scan generally results in my patients’ having deteriorated compliance, deteriorated management, and a deteriorated progression," he said. "I’ve come to realize that the PET scan is really amazingly helpful in seeing patients in mild cognitive impairment states that are very damaged. The issue for me in preventive medicine is, can I predict who’s going to get a bad PET scan, so we can break the process through all the techniques we have, from treating depression to nutritional therapy, hormonal therapy, and lifestyle therapy."

Dr. Braverman presented a study of 85 subjects with mild cognitive impairment who received a comprehensive medical evaluation, including functional FDG [¹⁸fluorodeoxyglucose]–PET imaging, neuropsychological testing, and P300. In all, 44 had hypometabolism on PET and the rest had normal brain metabolism. Both groups had a mean age in the mid-50s.

The key study finding was that the two groups differed significantly in terms of their P300 voltage and latency. The mean P300 latency was 346 ms in the group with hypometabolic PET findings, compared with 323 ms in the normal metabolic group. The mean P300 voltage was 3.25 mV in the hypometabolic group and 5.0 mV in those with normal metabolism on functional PET.

It’s known that P300 latency increases with advancing age at a rate of 7-10 ms per decade. Since the mean difference between the hypometabolic and normal metabolic PET groups was 23 ms, that means that the hypometabolic patients exhibited the slower brain-processing speeds that are more typical of individuals at least 20-30 years older, according to Dr. Braverman.

The next step in his research project will be to try to identify the combination of P300 latency and voltage values and neuropsychological test results that are optimally predictive of which patients with memory and attention complaints are sufficiently early in cognitive decline that they haven’t developed hypometabolism, he added.

Session chair Dr. Jeremy D. Schmahmann indicated that this novel preventive strategy is still far from ready for routine use in clinical practice.

"It’s an interesting beginning, and hopefully we’ll see it progress," commented Dr. Schmahmann, professor of neurology at Harvard Medical School and director of the ataxia unit and the laboratory of neuroanatomy and cerebellar neurobiology at Massachusetts General Hospital, both in Boston.

Dr. Braverman indicated he had no relevant financial interests.

DENVER — The P300 evoked-potential component of the EEG may provide a readily accessible early window on cognitive decline well in advance of the irreversible changes leading to dementia.

That’s the working hypothesis of Dr. Eric Braverman, who noted that the P300 is an easy-to-administer test that takes just 10 minutes and is well suited for use as a screening tool for middle-aged patients in primary care physicians’ offices.

"My vision is that we’re all going to have laptop brain-health checkups," he declared at the annual meetingof the American Neuropsychiatric Association.

He drew a parallel between dementia and coronary heart disease: Much as electrophysiological deterioration of the heart (as elicited by an exercise treadmill test) is generally antecedent to the massive metabolic derangement of an MI, he is convinced that electrophysiological deterioration in the brain (as expressed in delayed P300 evoked-potential latency) precedes the hypometabolic changes seen on functional PET imaging.

"The P300 is like a stress test of the head to find early deterioration in the [electrophysiological] parameters of voltage – a marker of overall brain cellular atrophy – and latency, or brain-processing speed," according to Dr. Braverman of Cornell University, New York, who is the founder and director of PATH (Place for Achieving Total Health) Medical.

"Thirty-five years of experience have shown me that a positive metabolic PET scan generally results in my patients’ having deteriorated compliance, deteriorated management, and a deteriorated progression," he said. "I’ve come to realize that the PET scan is really amazingly helpful in seeing patients in mild cognitive impairment states that are very damaged. The issue for me in preventive medicine is, can I predict who’s going to get a bad PET scan, so we can break the process through all the techniques we have, from treating depression to nutritional therapy, hormonal therapy, and lifestyle therapy."

Dr. Braverman presented a study of 85 subjects with mild cognitive impairment who received a comprehensive medical evaluation, including functional FDG [¹⁸fluorodeoxyglucose]–PET imaging, neuropsychological testing, and P300. In all, 44 had hypometabolism on PET and the rest had normal brain metabolism. Both groups had a mean age in the mid-50s.

The key study finding was that the two groups differed significantly in terms of their P300 voltage and latency. The mean P300 latency was 346 ms in the group with hypometabolic PET findings, compared with 323 ms in the normal metabolic group. The mean P300 voltage was 3.25 mV in the hypometabolic group and 5.0 mV in those with normal metabolism on functional PET.

It’s known that P300 latency increases with advancing age at a rate of 7-10 ms per decade. Since the mean difference between the hypometabolic and normal metabolic PET groups was 23 ms, that means that the hypometabolic patients exhibited the slower brain-processing speeds that are more typical of individuals at least 20-30 years older, according to Dr. Braverman.

The next step in his research project will be to try to identify the combination of P300 latency and voltage values and neuropsychological test results that are optimally predictive of which patients with memory and attention complaints are sufficiently early in cognitive decline that they haven’t developed hypometabolism, he added.

Session chair Dr. Jeremy D. Schmahmann indicated that this novel preventive strategy is still far from ready for routine use in clinical practice.

"It’s an interesting beginning, and hopefully we’ll see it progress," commented Dr. Schmahmann, professor of neurology at Harvard Medical School and director of the ataxia unit and the laboratory of neuroanatomy and cerebellar neurobiology at Massachusetts General Hospital, both in Boston.

Dr. Braverman indicated he had no relevant financial interests.