SUPPORT FOR CLOSER LINK BETWEEN NEUROLOGY AND PSYCHIATRY GAINS MOMENTUM

Educators have given widespread support to increased integration of neurology and psychiatry, as reported in the August Journal of Neurology, Neurosurgery, and Psychiatry.

Frederick Schon, MBBS, MRCP, and colleagues analyzed questionnaire survey results from 105 trainees (specialist registrars), trainers, and teachers (undergraduate coordinators); 55 were from the neurology field, while the remaining 50 had a psychiatry background. Most respondents were "keen" on the idea of integrating the two disciplines and were "unkeen" on separating the fields. From a possible 15 joint teaching topics, respondents were supportive or very supportive for seven, including somatization, dementia, chronic pain, and pharmacology. Another seven received favorable reactions, while the remaining topic, eating disorders, did not receive support. Among six possibilities for joint training opportunities, trainees were supportive of joint education, clinical and patient management sessions, and outpatient clinics.

The team regarded their finding that the support that psychiatrists gave to the integrated approach tended to be stronger than that of the neurologists, as "perhaps surprising, as the importance of psychiatry to everyday neurological practice was recently emphasized when it was shown that as many as one third of new outpatient attendees have so-called medically unexplained symptoms."

The researchers noted that the ultimate goal for integrating the two disciplines was the improvement of patient care. "We believe that bringing the two disciplines closer will extend the spectrum of knowledge and skills of both specialties: neurologists can gain greater expertise in many aspects of chronic, community-based care as well as in ‘soft’ syndromes (medically unexplained symptoms), and psychiatrists in the diagnosis, investigation, and management of patients with relevant brain disorders," they noted.

Dr. Schon and colleagues gave several possible applications of their findings. One suggestion was the creation of a basic clinical neuroscience training program that would "enable junior doctors considering specializing in neurology, neurosurgery, psychiatry, rehabilitation medicine, and elderly care medicine to attend a neurology attachment before starting specialist training," they pointed out. The researchers also suggested the establishment of joint training days for specialist registrars in both the neurology and psychiatry disciplines.

"Each medical school should increasingly link the teaching of basic neuroscience, psychiatry, neurology, and psychology," Dr. Schon’s group stated. "These results strongly suggest that trainees and trainers are open to a more integrated approach."

Suggested Reading
Schon F, MacKay A, Fernandez C. Is shared learning the way to bring UK neurology and psychiatry closer: what teachers, trainers and trainees think. J Neurol Neurosurg Psychiatry. 2006;77:943-946.

ALZHEIMER'S DISEASE PATHOLOGY IN OLDER PERSONS WITHOUT DEMENTIA?

Older persons without dementia or mild cognitive impairment (MCI) can meet neuropathologic criteria for Alzheimer’s disease, according to D. A. Bennett, MD, and colleagues. Their findings were reported in the June 27 Neurology.

he researchers conducted two community-based studies of aging and Alzheimer’s disease in which more than 2,000 participants did not have dementia. Brain autopsies were performed in 134 subjects who died. Based on National Institute on Aging–Reagan neuropathologic criteria, two of the participants had a high likelihood of Alzheimer’s disease, while 48 had an intermediate likelihood of the disease. Cerebral infarctions were found in 29 participants, and Lewy bodies were observed in 18 subjects. In tests of episodic memory, participants meeting criteria for intermediate or high likelihood of Alzheimer’s disease had a score approximately a quarter standard unit below scores of those who did not meet criteria. Additionally, persons meeting criteria had a mean Mini-Mental State Examination score of 28.2 when proximate to death, while those not meeting criteria had a score of 28.4.

The investigators noted that several terms, such as pathologic aging, preclinical Alzheimer’s disease, and subclinical Alzheimer’s disease, describe the condition suggested by their findings: that persons with MCI or without clinically evident cognitive impairment can have the pathology of Alzheimer’s disease. "It is now well established that MCI is associated with significant morbidity and mortality, and Alzheimer’s disease pathology in persons without clinically evident cognitive impairment now appears to be associated with subtle cognitive deficits," stated the researchers.

"The results also provide evidence in support of the idea that some type of neural reserve can allow a large number of older persons to tolerate a significant amount of Alzheimer’s disease pathology without manifesting obvious dementia," pointed out Dr. Bennett and colleagues. "[T]he functional organization of the brain was thought to be redundant, and a considerable amount of tissue destruction needs to occur before the system is compromised and disease becomes clinically evident. However, brain and neocortical size are crude correlates of cognition, at best, and they explain little of the marked individual differences in the information processing capacity of humans. This has led some to posit that they also differ in their efficiency and ability to respond to environmental challenges (eg, disease pathology), a term sometimes called cognitive reserve."

The researchers noted that their findings "suggest that even slight impairment of episodic memory in older persons may signify the presence of pathology rather than representing a normal consequence of aging."

Suggested Reading
Bennett DA, Schneider JA, Arvanitakis Z, et al. Neuropathology of older persons without cognitive impairment from two community-based studies. Neurology. 2006;66:1837-1844.

APOE e4, CSF AB42, AND ALZHEIMER'S DISEASE

Decreasing concentration of ß-amyloid 42 (Ab42) in the CSF of apolipoprotein E e4 (APOE e4) carriers may occur early in adult life, according to findings published in the July Archives of Neurology.

Elaine R. Peskind, MD, and colleagues assessed 184 community volunteers ages 21 to 88 who had normal cognition. Results showed that while the concentration of Ab40 in CSF did not decrease significantly with age, there was a sharp decrease in Ab42 concentration beginning in the sixth decade of life in participants with the APOE e4 allele. The age-associated decrease in CSF Ab42 concentration was significantly greater in subjects with the APOE e4 allele compared to those without it, the investigators reported.

"Our results suggest that the APOE e4 allele is associated with selective alteration of the fate of Ab42 ... that results in decreasing concentration of Ab42 in CSF during the normal adult life span," Dr. Peskind and colleagues stated. "In persons with the APOE e4 allele, decline in CSF Ab42 concentration possibly begins in young adulthood, followed by marked acceleration of this decline beginning in midlife—decades before clinical manifestations of Alzheimer’s disease."

The researchers’ findings point to the possibility that early change of Ab42 concentration in APOE e4 allele carriers is a "key initiating factor in Alzheimer’s disease pathogenesis. Measuring Ab concentration in CSF provides an indirect estimation of the net effect of production, clearance, aggregation, and deposition; therefore, we cannot determine which of these factors is most important." Dr. Peskind’s team recommended that for therapeutic strategies to have the most substantial impact on amyloid deposition, persons in early midlife or even younger might need to be targeted. "Primary prevention trials for Alzheimer’s disease targeting elderly persons may be too late to affect the early stages of disease pathology," the researchers pointed out.

Suggested Reading
Peskind ER, Li G, Shofer J, et al. Age and apolipoprotein E*4 allele effects on cerebrospinal fluid ß-amyloid 42 in adults with normal cognition. Arch Neurol. 2006;63:936-939.

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