Diagnostic profile of young and middle-aged memory clinic patients
Vraamark Elberling T, Stockholm J, Hogh P and Waldemar G;
Commented by , 16 Dec 2002
Aim of the study
Establish the cause of cognitive and behavioral symptoms in younger patients referred to memory clinics.
Method
Prospective study of persons referred to a multidisciplinary outpatient memory clinic operating in the neurological setting of a teaching hospital in Copenhagen, Denmark. The analysis includes all consecutive subjects <60 years referred by family practitioners, specialists or other hospitals over a period of 54 months.
The routine evaluation included neurological examination, MMSE, laboratory blood tests, EKG. Other assessments were done as required clinically, including neuropsychological testing, psychiatric evaluation, and brain imaging.
A consensus report was completed by the multidisciplinary team, dividing subjects into (1) dementia, (2) selective cognitive deficits, (3) no cognitive deficits. A primary diagnosis as to the cause of dementia or selective cognitive deficit was then established. The group of young and middle age subjects (<60) was compared with older subjects (> 60) by chi square two-tailed test. When the expected frequency was <5 in one or more cells, the Fisher exact test was used.
Results
Out of 1000 patients referred, 314 were <60 years (175 men, 139 women), mean age 47.6 years (range 17 to 59). Their mean MMSE was 26.8. Neuropsychological examination was done in 65%, psychiatric evaluation in 35%, brain imaging in 85%.
Only 15% fulfilled DSM-IV criteria for dementia, 17% had insolated cognitive deficits not fulfilling DSM-IV criteria for dementia, 13% had mild subjective cognitive symptoms that could not be further classified, 55% had no cognitive deficits.
In terms of primary diagnosis, 14.6% had a depression, 5.1% had ‘mild organic cognitive syndrome’ as defined by ICD-10, 4.5% had personality disorder, 4.5% had alcoholic brain damage.
In the group of young to middle-age patients with dementia, Alzheimer’s disease (AD) was the most common diagnosis, but frontal lobe and alcohol-related dementia were more common than in the older age group (p<0.001 and p<0.01 respectively).
Discussion
The authors highlight the obvious differences in the diagnostic profile of younger vs older persons referred to a memory clinic, where only 47 patients with dementia were found out of 314 in persons <60 years, whereas 79 had some type of psychiatric disorder.
Among the 16 with a diagnosis of ‘mild organic cognitive syndrome’, many would fit the criteria for Mild Cognitive Impairment (MCI).
Overall this survey of diagnosis made in an academic, very high caliber memory clinic among young persons with memory and other cognitive complaints raises a number of issues that need to be addressed as MCI becomes a fashionable term in the medical community and even in the well educated public, and randomized clinical trials are under way to delay conversion from MCI to AD: (1) what assessments can be done in family practice? (2) who to refer? (3) where to refer?
The latter point is partly answered in this article: a multidisciplinary approach is necessary for optimal diagnosis and management, although the cost-effectiveness of such an assessment for persons <60 years remains to be established.