S4.5 Diagnosis of causes of cognitive impairment and dementia, lessons learned from the Nordic Network in Dementia Diagnostics
Chair: Knut Engedal
A network of eight Memory Clinics in five Nordic countries and Lithuania was established in 2010 coined “Nordic Network in Dementia Diagnostics” or NIDD. NordForsk originally financed the network for meetings and seminars. In addition, the network planned and conducted a multicentre scientific study, financed by Kavli Research Foundation, validating a novel method of electrophysiology (EEG) for diagnosis of causes of cognitive impairment and dementia. The network is now entering a new multicentre study that is a follow up of the former one. At this symposium, the concepts of cognitive impairment and dementia will be discussed as well as the different methods of diagnosis as used in the centres. The cornerstone of diagnosis is the history from the patient and his/her close relative and detailed evaluation of cognition by neuropsycological methods. In addition, various types of investigations for the presence of different biomarkers are used. These are quantitative measures of atrophy of brain structures with Magnetic Resonance Imaging (MRI), activity of brain tissue measured by radioactive sugar ligands in Positron Emission Tomography (FDG-PET), amyloid load of the brain measured with amyloid PET or amyloid in the Cerebrovascular fluid (CSF), signs of neuronal death measured by tau proteins in the CSF and electrophysiological activity of the brain measured by quantitative Electroencephalography (qEEG). No single method is sufficient and therefore the diagnosis depends on a weighted evaluation. Clinical signs of psychiatric symptoms, prevalent in dementia are also of great importance primarily of two reasons; they can give a clue to the cause of cognitive impairment and secondly, they can be treated more effectively than the cognitive symptoms.
S4.5.1 Cognitive Impairment and dementia, definitions and major causes
Landspitali University Hospital, Reykjavik, Iceland
When a patient enters a Memory Clinic, the main question is whether the symptoms are due to a progressive neurodegenerative disorder or if they have a more benign cause. With increasing knowledge of the biological disturbances of these disorders, here exemplified by the most common disorder, Alzheimer´s disease, definitions are changing. The first criteria, primarily intended for research purposes, were published in 1984 and used unchanged for more than two decades. Since 2007, an era of rapid change of knowledge has been reflected by the criteria being updated every few years, a process that is still on-going. Two major changes are being made. The stages before dementia are defined in a more precise manner and biomarkers are increasingly used. This process of changing criteria will be described and how this is reflected in work-up and research in the Nordic Memory Clinics.
S4.5.2 The use of MRI and CT in the evaluation of cognitive disorders
Karolinska Institutet, Stockholm, Sweden
In the evaluation of cognitive disorders such as dementia, structural imaging of the brain has been fundamental. Previously mainly to detect tumors and other space occupying processes. Today due to increased knowledge MRI and CT can be used of help to differ between dementia disorders such as Vascular dementia and Alzheimer’s disease. In many national guidelines on dementia care and dementia evaluation, a structural image evaluation of the brain is almost mandatory in the clinical work up. In modern imaging with MRI and CT the evaluation of images is performed with a combination of image analysis and advanced multi variate statistical methods. In this way the evaluation single patients will be more and more automatic with little influence from the human eye. The recognition of specific areas of atrophy, even in very small areas and subtle changes in the white matter have helped to increase the possibility to differentiate between patients with Alzheimer’s disease, frontotemporal dementia and vascular dementia.
S4.5.3 The use of FDG-PET and amyloid PET in diagnosis of Alzheimer´s disease
Birgitte Bo Andersen
Rigshospitalet, Copenhagen, Denmark
S4.5.4 CSF analysis as biomarkers for Alzheimer´s disease
Oslo University Hospital, Norway
The cerebrospinal fluid (CSF) biomarkers amyloid β (Aβ), phospho tau (P-tau) and total tau (T-tau) reflect neuropathological changes seen in Alzheimer’s disease (AD) patients, and are used increasingly to support a clinical diagnosis of AD. However, the CSF biomarkers are not specific for AD, but may be pathological in other conditions as well. The diagnostic power of these biomarkers has been reported to vary among different studies. The results are poorer when heterogeneous groups of patients have been included compared to studies where patients with Alzheimer’s dementia and healthy controls have been studied. Not only an AD diagnosis, but other factors as age, the presence of one or two APOE ε4 alleles and the degree of cognitive impairment are associated with the levels of the CSF biomarkers as well. At last, the levels of the CSF biomarkers (especially Aβ) are vulnerable for both interlaboratory and intralaboratory variations as well as for preanalytical variability due to different routines in handling the samples. These aspects are important to be aware of when we interpret the CSF biomarker results in clinical daily practice.
S4.5.5 Neuropsychiatric symptoms in cognitive impairment and dementia
Maria Lage Barca
Norwegian National Advisory Unit on Ageing and Health, Oslo University Hospital, Norway
Neuropsychiatric symptoms (NPS) include mood
symptoms (depression, mania), anxiety, apathy, sleep, appetite, behavioral symptoms
(aggression, agitation), disinhibition, irritability, delusions and
hallucinations. Prevalence rates are as high and increase with dementia
severity. Patients with NPS in dementia have a poor prognosis, such as
cognitive decline, functional impairment, worse quality of, caregiver
burden, institutionalization and higher mortality. Different prevalence rates
of NPS have been reported in different dementia disorders. Patients with
Frontotemporal dementia (FTD) typically present NPS before the cognitive
symptoms. However, there is growing evidence
that other types of dementia (not only FTD) can also have NPS before the
cognitive symptoms. Depression and apathy have been shown to be a prodromal
symptom of Alzheimer’s disease and other symptoms, such as psychosis, have
recently been reported as preceding the cognitive symptoms in AD. Additionally,
NPS are common in mild cognitive impairment (MCI) and associated with poorer prognosis,
including conversion to dementia. The annual conversion rate for MCI to AD in
patients with NPS is estimated to be around 25% in contrast to an annual rate of 10-15% for
MCI without NPS. This presentation will review the
literature on the topic and highlight the importance of evaluating NPS in
cognitive impairment and dementia.