A multidisciplinary memory clinic in a neurological setting: diagnostic evaluation of 400 consecutive patients

This report describes the operation of a multidisciplinary university hospital memory clinic in a neurological setting, and the diagnostic evaluations in 400 consecutive patients referred for cognitive symptoms and possible dementia during a period of 27 months (1 September 1995-31 December 1997). The mean age of the patients was 63.6 years (range 19-97). On clinical and neuropsychological examination, 46% of the patients fulfilled DSM IV criteria for dementia, 5% had selective amnesia, and 14% had other selective cognitive deficits. The remaining patients had either no significant cognitive deficits (31%) or were not evaluable (4%). A wide range of disorders from the fields of neurology, psychiatry, neurosurgery and internal medicine were identified as the underlying etiologies for the cognitive symptoms. Potentially reversible conditions were observed in 26% of the patients, not including the 11% in whom no specific underlying disease was identified. Concomitant conditions or risk factors with a potential influence on cognitive functions were identified in 61% of the patients. Diagnostic evaluation of patients with mild to moderate cognitive symptoms and possible dementia is an integrated multidisciplinary task, which should focus on the identification of non-progressive and potentially reversible etiologies, co-morbidity, selective cognitive deficits, and rare or atypical neurological conditions, as well as on the early identification of common progressive dementia disorders.     

Diagnostic profile of young and middle-aged memory clinic patients

With the objective of characterizing the underlying conditions in younger patients with cognitive symptoms, 314 consecutive patients were studied, aged <60 years, referred to a multidisciplinary memory clinic over a period of 54 months. Fifteen percent of the patients fulfilled Diagnostic and Statistical Manual IV criteria for dementia, 17% had selective cognitive deficits, and 55% had no cognitive deficits. Cognitive symptoms in younger patients rarely reflect dementia but more often other medical and psychiatric conditions.     

Idiopathic normal-pressure hydrocephalus: evaluation and findings in a multidisciplinary memory clinic

The diagnostic evaluation of patients with possible idiopathic normal-pressure hydrocephalus (INPH) is traditionally performed in the settings of either neurological, neurosurgical or psychiatric departments. The diagnostic procedure and findings in 71 consecutive patients referred with a clinical and radiological suspicion of INPH to our out-patient multidisciplinary memory clinic are evaluated. Primary diagnoses and potential concomitant disorders considered of secondary importance for the symptomatologies were established. Abnormal hydrodynamics, demonstrated by intraventricular pressure monitoring and infusion test were mandatory for the diagnosis of INPH. Mean age was 68 years and mean Mini-Mental State Examination (MMSE) score was 22. DSM IV criteria of dementia were fulfilled in 42%. In half of the referred patients (n=36), the suspicion of INPH was already disproved subsequently to the evaluation programme performed in the outpatient clinic. The main primary diagnosis was cerebrovascular disease (CVD) comprising 27% (n=19) of the referrals, whereas INPH was diagnosed in only 20% (n=14). Shunt improvement rate was 72%. The remaining patients were diagnosed as having one of 26 different conditions. A multiplicity of disorders mimics the INPH syndrome, with CVD being the primary differential diagnosis. Evaluating patients with possible INPH in an outpatient multidisciplinary memory clinic is an effective and rational diagnostic approach.     

Reversible dementia in elderly patients referred to a memory clinic

Dementia has a reversible cause in some cases, and these should be diagnosed without over-investigating the many patients with irreversible disease. We prospectively studied the prevalence of reversible dementia in a memory clinic, determined the added value of investigations compared with clinical examination and assessed the outcome of treatment of potentially reversible causes by measuring (1) cognition, (2) disability in daily functioning, (3) behavioural changes and (4) caregiver burden. Two hundred patients aged 65 years and over were examined, using the CAMDEX-N. If they were demented, the probable cause was diagnosed clinically and confirmed or excluded by a standard set of investigations, which were done in all patients. Of the patients, 170 (mean age 79.2 years) were demented; 31 were treated for potentially reversible causes. At follow-up after 6 months, no patients showed complete reversal of dementia. Five patients improved on clinical impression, but only one on clinicial measurement. Thirty patients were cognitively impaired, but not demented; seven were treated. Judged clinically, three patients improved, but on assessment only one did so; she recovered completely. Blood tests often produced diagnostic results that were not expected clinically, but electroencephalography and computed tomography of the brain did not. None of the investigations had an effect on outcome of dementia after treatment. We conclude that in elderly patients referred to a memory clinic, the prevalence of reversible dementia is of the order of 1%, if outcome after treatment is assessed by a standardized measurement. We recommend blood tests in all patients, to detect not only metabolic causes of dementia but also co-morbidity possibly worsening the dementia. Other investigations can be performed on clinical indication. Clinical evaluation remains the mainstay of diagnosis in dementia. Received: 29 March 1996 Received in revised form: 11 June 1996 Accepted: 23 August 1996     

Suspected dementia: evaluation of 323 consecutive referrals

A neurological outpatient department studied 323 consecutive referrals for suspected dementia: 135 (41.8%) were not demented. Of the patients 12.1% had diffuse cognitive disorder; 10.2% circumscribed memory disorder; 0.9% other circumscribed cognitive disorder, 14.2% psychiatric disorder, and 4.3% were judged to be normal. Of the nondemented, 44.1% had a potentially treatable cause for their cognitive symptoms; in 27.4% it was depression. The total of demented patients was 188 (58.2%): 38.8% had primary degenerative dementia; 37.2% vascular dementia including combined degenerative and vascular dementia; and 23.4% had a specific cause. Patients with specific cause were significantly younger than those with other causes of dementia. A potentially treatable cause was found in 10.7% of all demented patients, the most common being metabolic disorders, meningioma, hydrocephalus, subdural haematoma, and depressive pseudodementia.     

Dementia in Parkinson's Disease: Its Incidence and a Possible Relationship with Dopa-refractory Symptoms

Background : The diagnostic criteria for dementia in idiopathic Parkinson's disease (PD) remain controversial. In PD, general intelligence is relatively spared, although executive function is commonly impaired.
Methods : Following the Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM-IV), in this study we defined dementia in PD as a combined impairment of memory and executive function, and evaluated its incidence and its relationship with other clinical features.
Results : The prevalence of dementia among patients with PD was estimated to be 20–30% in an outpatient clinic and was found to be associated with the severity of motor impairments, especially Dopa-refractory symptoms. On the other hand, no relationships were observed between the prevalence of dementia and patient age or age of onset.
Conclusion : These data suggest that cognitive deficits, comprising dementia syndrome in PD, are mainly due to common neurodegenerative processes of non-dopaminergic systems, but not to other concomitant diseases, such as Alzheimer's disease.     

A prospective study of reversible dementias: frequency, causes, clinical profile and results of treatment

BACKGROUND: Dementia due to potentially reversible etiologies is an important group of dementias to be identified not only because of the number of such Patients encountered but also due to the potential for substantial improvement with treatment. AIMS: To prospectively investigate the frequency and causes of dementias with potentially reversible etiologies; to examine the clinical features of this subgroup with a view to identifying a signature profile and to determine if this potential reversibility translates into actual reversibility with appropriate treatment. SETTING AND DESIGN: A prospective longitudinal study of patients with dementia presenting to the outpatient services of a tertiary referral hospital. Methods: All Patients above 40 years referred for evaluation of cognitive complaints were serially enrolled and underwent clinical examination, various laboratory tests and neuroimaging. Patients were followed-up for one year. STATISTICAL ANALYSIS: One way analysis of variance for continuous variables followed by post hoc comparisons using Scheffe's procedure. RESULTS: A total of 129 patients met Diagnostic and Statistical Manual of Mental Disorders edition 4 (DSM IV) criteria for dementia and qualified for inclusion into the study. Twenty-four patients (18%), all with moderately severe cognitive [mean mini mental state examination (MMSE) score +/- SD = 17.9 +/- 4.8] and neuropsychiatric [mean neuropsychiatric inventory (NPI) score +/- SD = 30.7 +/- 8.7] dysfunction were diagnosed to have reversible causes - neuroinfections in 11 patients, normal pressure hydrocephalus in 8 patients and vitamin B12 deficiency in 5 patients. The majority of these patients had gait and urinary dysfunction reminiscent of subcortical dementias. These reversible causes were clinically suspected in only 58% of patients. In 20/24 patients in whom follow up was possible mean MMSE score had improved to 22.2 and mean NPI score had improved to 8.0, following 6 months of treatment. CONCLUSIONS: Reversible causes, especially neuroinfections and vitamin B12 deficiency accounted for 18% all dementias in this study. The majority of these conditions was not clinically suspected though resulting in moderate to severe cognitive and psychiatric dysfunction. Most of these patients had a subcortical pattern of dementia and showed substantial improvement with treatment.     

Motor function in subjects with mild cognitive impairment and early Alzheimer's disease

Basic mobility, balance, gait and dual-task performance were characterised in 140 consecutive subjects referred to a multidisciplinary university hospital in a geriatric setting for cognitive symptoms and possible dementia. After completion of an extensive diagnostic evaluation, subjects were classified into four diagnostic categories: no cognitive impairment, mild cognitive impairment, Alzheimer's disease (AD) and other dementia. Mean age was 57 +/- 9.2, 60 +/- 7.3, 68 +/- 9.9 and 64 +/- 10.5, respectively. Data on motor function, medication use and presence of white matter changes were evaluated and compared between the diagnostic groups. Motor function seems to be affected in very mild AD but not in mild cognitive impairment, as assessed with performance-based tests. AD subjects were slowed and had difficulties in dual-task performance requiring concurrently performing a cognitive task while walking.     

A memory clinic at a geriatric hospital: a report on 577 patients assessed with the CAMDEX over 9 years

OBJECTIVE: To report 9 years' experience of an Australian memory clinic using the -Cambridge Mental Disorders in the Elderly Examination (CAMDEX) assessment schedule, summarizing patient demographics, diagnoses at presentation and the utility of four instruments used in distinguishing patients with and without dementia. METHODS: All patients seen at the clinic between December 1989 and September 1998 were assessed using the CAMDEX. Diagnoses were determined according to criteria of the International Classification of Diseases, tenth edition (ICD-10). RESULTS: The mean age of 577 patients seen was 72.9 years and 60.8% were female. Over 40% fulfilled ICD-10 diagnostic criteria for dementia in Alzheimer's disease. A further 24% had another dementing illness. Only 28 patients were "normal". There was no significant difference in the ability of the 107-item Cambridge cognitive examination, the 30-item mini-mental state examination, the 10-item abbreviated mental test score and the 26-item informant questionnaire on cognitive decline in the elderly to differentiate dementia patients from those who were normal or had functional psychiatric disorders. The four cognitive screening tools had high correlations with one another (r = - 0.57 to 0.93). CONCLUSION: Patient demographics and diagnoses were similar to those found in other clinics. Most people who attended the memory clinic had significant cognitive or psychiatric disorders.     

Potentially reversible dementia: a review.

Potentially reversible dementia is reviewed with reference to diagnosis, causes and outcome. Many disorders which cause cognitive impairment, such as drug toxicity and depression, fail to meet diagnostic criteria for dementia. These tend to have the best prognosis. Studies of the neuropsychiatric syndromes associated with disorders causing potentially reversible dementias suggest that dementia is an infrequent outcome and when it does occur, few cases recover. Factors predictive of improvement are short duration of symptoms and mild degree of cognitive impairment, usually subcortical in type. It is suggested that potentially reversible cognitive impairment would be a more accurate term as many cases are due to delirium and depression. While cases of well established dementia do not require extensive investigation, all cases should have a thorough clinical assessment as in many instances dual pathology exists and all require psychosocial management.     

Demenz als Erstsymptom bei spät beginnender Multipler Sklerose

Cognitive impairment is meanwhile accepted as a well-known symptomatology affecting up to 60% of the patients even in the early disease course of multiple sclerosis (MS). After a longer duration the development of dementia is not unusual. However, cognitive dysfunction as the primary or only manifestation of MS is thought to be rare. We report on four elderly patients referred to the memory clinic of our psychiatric university hospital because of beginning dementia. All of them were found to have evidence of a chronic inflammatory CNS process compatible with the diagnosis of MS. At the beginning of their symptomatology all patients were older than 60 years . Just in one case, progressive gait disturbances beginning after cognitive decline contributed to restriction in the activities of daily living. Data of 239 cases of the literature were reviewed and revealed motor disturbances as the main initial symptom and often a primary progressive course with unfavourable prognosis in late onset MS. Until now dementia as the primary symptomatology has not been described in patients older than 60 years. Possibly MS as a differential diagnosis in dementia as well as cognitive impairment as an initial symptom of MS is under-recognized.     

Cognitive and demographic determinants of dementia in depressed patients with subjective memory complaints

BACKGROUND: Previous studies showed that late-life depression with subjective memory complaints (SMC) may be associated with an increased risk of developing dementia. However, not all such patients have cognitive decline. The aim of this longitudinal study was to identify possible clinical determinants of progressive deterioration in depressed elderly patients with SMC. METHOD: Forty-one consecutive patients referred to a memory clinic because of persistent SMC were investigated and received an ICD-10 diagnosis of mild to moderate depression. Over a mean follow-up period of 15 months, 9 of them (22%) developed dementia. Statistical analysis included Mann-Whitney U and Fisher's exact tests as well as univariate and multivariate logistic regression analyses to assess the relationship between cognitive decline and clinical, demographical and neuropsychological characteristics at baseline. RESULTS: Age at baseline was associated with subsequent dementia, and performance on immediate verbal prose recall and a visual organization test at the initial assessment were worse in those who showed cognitive decline. In a multivariate model, age and immediate recall predicted 32.7% of the cognitive variability, with an additional 2.4% when a visual organization test was added. There was no correlation between cognitive performance and severity of depression at baseline. The study was limited by a small sample size, the nondistinction of depressive subtypes and the absence of a formal neuropsychological assessment on follow-up. CONCLUSION: Impairment of the executive component of working memory as well as limited access to visual knowledge may predict cognitive deterioration in depressed patients with subjective memory complaints.     

Diabetes and cognitive impairment

BACKGROUND: Diabetes is a risk factor for dementia,but the issue whether this concerns only vascular dementia or also Alzheimer's disease is debated. We compared the clinical diagnoses and abnormalities on brain MRI in patients with or without diabetes who received standardised, detailed diagnostic studies at a memory clinic, in order to establish whether one specific type of dementia or specific MRI abnormalities were more common in diabetes. PATIENTS AND METHODS: Patients who visited our memory clinic between January 2002 and June 2004 were divided into a group with (n = 42) or without diabetes (n = 389). The diagnoses were recorded, and MRI scans were rated for (sub)cortical atrophy, medial temporal lobe atrophy, infarctions, and white matter changes. RESULTS: The proportion of Alzheimer's disease (36% versus 28%; OR 1.1 (95% CI 0.5-2.2), adjusted for age and sex), vascular dementia (5% versus 2%; OR 2.4 (0.5-12.1)), and so called "cognitive impairment no dementia" (24% versus 17%; 1.3 (0.6-2.9)) was similar in patients with or without diabetes. On MRI lacunar and cortical infarctions were more common and cortical atrophy more pronounced among diabetic patients. By contrast, the severity of white matter changes was similar in the two groups. CONCLUSION: The relative frequency of different diagnoses among diabetic and non-diabetic patients attending a memory clinic was similar, indicating that diabetes does not predispose to one particular subtype of dementia. The imaging findings support the notion that the increased risk of cognitive decline and dementia in elderly subjects with diabetes is due to dual pathology, involving both cerebrovascular disease and cortical atrophy.     

Mild cognitive impairment: a systematic review

MCI is a nosological entity proposed as an intermediate state between normal aging and dementia. The syndrome can be divided into two broad subtypes: amnestic MCI (aMCI) characterized by reduced memory, and non-amnestic MCI (naMCI) in which other cognitive functions rather than memory are mostly impaired. aMCI seems to represent an early stage of AD, while the outcomes of the naMCI subtypes appear more heterogeneous--including vascular dementia, frontotemporal dementia or dementia with Lewy bodies--but this aspect is still under debate. MCI in fact represents a condition with multiple sources of heterogeneity, including clinical presentation, etiology, and prognosis. To improve classification and prognosis, there is a need for more sensitive instruments specifically developed for MCI as well as for more reliable methods to determine its progression or improvement. Current clinical criteria for MCI should be updated to include restriction in complex ADL; also the diagnostic and prognostic role of behavioral symptoms and motor dysfunctions should be better defined. A multidisciplinary diagnostic approach including biological and neuroimaging techniques may probably represent the best option to predict the conversion from MCI to dementia. In this review we discuss the most recent aspects related to the epidemiological, clinical, neuropathological, neuroimaging, biochemical and therapeutic aspects of MCI, with specific attention to possible markers of conversion to dementia.     

Dexamethasone suppression test in depression with reversible dementia

Depression with reversible dementia occurs frequently in the elderly and may be a diagnostic problem. The 1-mg dexamethasone suppression test (DST) was performed in 175 elderly psychiatric patients. Abnormal DSTs occurred in both patients with primary degenerative dementia (n = 43, 34.9%) and those with major depression without cognitive dysfunction (n = 59, 66.1%). This finding suggests the presence of common hypothalamic abnormalities in these two disorders. There was no difference in the incidence of abnormal DSTs among depressives with a reversible dementia (n = 28, 78.6%), cognitively intact depressives (n = 59, 66.2%), and depressives who also had primary degenerative dementia (n = 24, 70.8%). An abnormal DST is not clinically useful in predicting the outcome of dementia in depressed patients with cognitive dysfunction.     

Who refuses the diagnostic assessment for dementia in primary care?

OBJECTIVE: Early screening and detection of dementia in primary care remains controversial. At least half of the patients identified as cognitively impaired by screening instruments do not meet criteria for dementia and some patients refuse further evaluation following a positive screen. The aim of this study was to identify the characteristics of patients who refuse a clinical diagnostic assessment for dementia after screening. DESIGN: Cross sectional study. SETTING: Seven primary care practice centers in Indianapolis. PARTICIPANTS: Four hundred and thirty-four individuals aged 65 and older who screened positive for dementia with a mean age of 74.6, 67% women, and 68% African-American. MAIN OUTCOME MEASURE: Patients' acceptance of undergoing a dementia diagnostic assessment that included neuropsychological testing, caregiver interview, and medical chart review. RESULTS: Among patients with positive screening results for dementia, approximately half (47.7%) refused further assessment to confirm their screening results. In a bivariate analysis, possible factors associated with a higher probability of refusing dementia assessment were older age and better screening score. In a multiple logistic regression model, performing well on the temporal orientation of the screening instrument was associated with a higher probability of refusing diagnostic assessment for dementia (OR = 1.37; p = 0.001). Also, African-American patients aged 80 and older were more likely to refuse the diagnostic assessment than African-Americans less than 80 years of age (OR = 3.1, p < 0.001), while there was no significant age association for white patients (OR = 0.9, p = 0.728). CONCLUSIONS: Older primary care patients who perceived themselves as having no cognitive symptoms refused dementia diagnostic assessment despite their positive screening results. We must improve our understanding of the decision-making process driving patients' beliefs and behaviors about the benefits and risks of dementia screening and diagnosis before implementing any broad-based screening initiatives for dementia.     

The prevalence and phenomenology of psychotic symptoms in dementia sufferers

One hundred patients referred to old age psychiatry services in the West Midlands and 25 patients referred to a memory clinic in Bristol with mild to moderate dementia were assessed using the GMS/HAS schedule together with a detailed inventory to assess their psychotic symptoms. On careful evaluation one patient did not have dementia. Eighty-three of the other 124 patients (66.9%) had at least one psychotic symptom. The prevalence of psychotic symptoms in the patients from the West Midlands and from the memory clinic in Bristol were extremely similar. Thirty-five per cent had at least one visual hallucination, 12.9% had at least one auditory hallucination, 48.4% had at least one delusional belief and 29.0% had at least one delusional misperception. Most individuals experienced their psychotic symptoms at a frequency between weekly and daily. Twenty-four had no insight into their psychotic symptoms and acted upon them, while only one patient had full insight into their symptoms. Thirty-seven subjects were mildly distressed and 14 were severely distressed by the psychotic symptoms they experienced. There was a trend for patients with cortical Lewy body dementia to be more likely to have psychotic symptoms than patients with Alzheimer's disease or vascular dementia. The symptom profile of psychotic symptoms in the different dementias was, however, very similar. The frequencies of individual psychotic symptoms are described in the text.     

Early diagnosis of dementia in primary care: a representative eight-year follow-up study in Lower Saxony, Germany

OBJECTIVE: To investigate whether primary care competency in early diagnosis of dementia might have changed during 1993 and 2001. METHOD: By means of a representative follow-up survey 122 out of 170 (71.8%) family physicians (FPs) in Lower Saxony, Germany, were randomly assigned to two written case samples presenting a patient with mild cognitive impairment (case 1a vs. 1b: female vs. male patient) and moderate dementia (case 2a vs 2b: vascular type (VD) vs Alzheimer's disease (DAT)), respectively. By means of a structured face-to-face interview, they were asked for their diagnostic considerations. RESULTS: In comparison to 1993, dementia was significantly more frequently considered. However, there was a striking tendency in overestimating vascular aetiology and under-diagnosing probable DAT (case 1a/1b: DAT: 11.0% in 1993 vs 26.2% in 2001; VD: 2.1% in 1993 vs 17.2% in 2001). As a possible contributor to a dementia syndrome, concomitant medication was considered only exceptionally (case 2a/2b: 4.4% in 1993 vs 2.5% in 2001). Physicians above 50 years of age showed a significantly lower early diagnostic awareness. At follow-up, the presumed interest in geriatric (psychiatric) topics dramatically faded from 66.9% to 35.2%. CONCLUSIONS: Our results demonstrate a persistent need of training efforts aiming at the early recognition of dementia, especially of DAT, in primary care.     

Organization of memory centers and prospects

The concept of memory centers is based on a multidisciplinary approach to memory disorders and dementia, especially Alzheimer's disease, a public health challenge. The first memory centers were established in the 80s in the US and the British Isles. The aims of these centers are to make a diagnosis (and to reassure the 'worried well'), to detect dementia, to provide a service for their management, to educate care takers, to evaluate new therapies, and to contribute to clinical and basic research. Follow-up is crucial. The first memory centers all experienced long delay to diagnosis of dementia and found that Alzheimer's disease was the first cause of consultation. These observations led to the creation of such centers in many countries. A survey of 20 French memory centers defined the "ideal memory center": an identified structure with a clinic and a day-care unit for diagnosis and follow-up, with neurological, psychological, psychiatric, and geriatric skills. It must be part of a medical and social network for the management of dementia and participate in a network of memory centers at the regional and national level. Relationships between dementia and somatic diseases, frequent in demented patients, are still poorly known. Dementia interferes with the clinical expression, the management, and the prognosis of somatic diseases, some of which, such as cardiovascular conditions, are possibly linked with dementia. Conversely, somatic diseases may rapidly worsen the cognitive state and induce delirium, leading to hospitalization. Medical wards are not all appropriate. Memory centers must also be involved in these care, educational and research issues.