“Progress is currently being made in dementia research particularly in diagnosis. Dementia diagnosis rely mainly on clinical information, and few decades ago, definite diagnosis could not come until an autopsy was conducted. With the advances in the genetic field, definite diagnosis is now possible much before death. Moreover, several biomarkers of the different dementia sub-types made differential diagnoses coming ever closer to diagnosing Alzheimer’s disease and other forms of dementia in their early stages, when cognitive impairments are still slight,” Dr Ana Verdelho (Santa Maria Hospital, University of Lisbon) reported at the 23rd Meeting of the European Neurological Society (ENS) in Barcelona. About 3,000 experts are discussing current developments in their field at this congress right now.
The expert sees big advances in diagnostic methods involving several biomarkers, and the combination of all methods can improve ability to the diagnosis. Atrophy in the medial temporal lobe can be depicted with magnetic resonance imaging (MRI). In addition, depositions of beta-amyloid in the brain, which play a part in the origins of the disease, can be measured or rendered visible in the brain of living patients with, for instance, Pittsburgh Compound B using positron emission tomography (PET). It is also possible to determine metabolism changes in the cerebral cortex using the PET process. In this case, radioactive flurdesoxyglucose (FDG) can be employed. Measure of cerebrospinal fluid proteins are added to improve diagnosis (Tau protein and ?-amyloid).
Tracking the degeneration of the brain
On the other hand, identification of genes responsible for some specific phenotypes enable changes in dementia patients over time to be described more accurately. One example came for one group of Italian researchers from Milan that reported at the ENS Meeting an atypical presentation of the repeated expansion in the C9orf 72 gene, with psychotic presentation. Another group described 63 year-old female patient with aphasia language disorders attributed to a progranulin mutation and described the neuroanatomical correlates of disease progression precisely. “Results such as these will be highly significant especially when the medical field comes up one day with protein-specific forms of therapy.” This is especially relevant for diseases with no treatment, so far, as in Frontotemporal degeneration. Data collected over time would also help to distinguish the various forms of dementia better from each other. Dr Verdelho: “Hopefully, several European projects are currently working together and I believe data will be of most interest. Precise determination helps in the selection of patients for studies that test new early-stage treatments such as we are currently trying with Alzheimer’s disease with the immunisation against protein beta-amyloid.”
Dementia not unavoidable
Observational studies presented at the ENS Meeting brought good news in that they underscored the fact that dementia in old age is not unpreventable: around 40 to 50% of 90 year-olds are not affected by it. From this fact, prevention basically appears to be possible. Attention is increasingly focused on prevention out of health policy considerations and because there is still no therapy. The consensus of the research conducted thus far is that prevention should begin at mid-life and continue into advanced old age. Dr Verdelho elaborated: “Education and life style – e.g. how a person deals with vascular risk factors and nutrition – play a part in dementia prevention, also physical activity and a person’s general state of health, for example, the control of diabetes and hypertension, and prevention of stroke.”
DNA testing for predicting disease later on
Further research presented at the ENS Meeting in Barcelona was devoted to clinical manifestations of individual forms of dementia. In addition, there is a wealth of new data on genes discovered in recent years. Dr Verdelho: “The medical field did not even associate many early clinical manifestations of, say, frontotemporal dementia with this disease.” In collaboration with colleagues from Portugal and France, they identified a gene mutation in a family in which there were many cases of frontotemporal lobe degeneration, and this mutation was also identified in dementia at a young age in a particular sporadic form (corticobasal syndrome). It was striking that this same mutation involving the progranulin gene manifested itself completely differently in terms of symptoms. Dr Verdelho: “This dementia can therefore occur in families as well as in individual patients.”
DNA testing is also relevant for still healthy progeny of dementia patients with gene mutation to determine whether or not they themselves will be affected by the disease in the future. “The risk can be 50%. We recommend that all family members have genetic counselling so they can be helped taking decisions to be or not screened and eventually organise their lives accordingly,” Dr Verdelho explained. Until now, very few relatives were interested in having genetic counselling. This hesitancy can be attributed to the lack of cures for those diseases. “What might motivate people to think about it or to participate in research studies is that in doing so they would contribute to the search for future therapies. The more patients we can find, the easier it is to conduct drug tests.”
Computers helping with brain rehabilitation
Advances in dementia therapy or prevention are a rare commodity at the moment and confined largely to the vascular form of the disease. Prevention of the latter has improved markedly in recent decades, focused in the prevention of cerebrovascular disease, according to the expert. Scattered successes in basic research in animal studies or at cell level are often difficult to apply to humans. Dr Verdelho: “For this reason, researchers are taking the neuropsychology path to make progress, as shown by current Czech pilot studies with computer-assisted cognitive rehabilitation. There can be a large number of widely diverging factors in patients, however, which has turned out to pose a difficulty in these training approaches.”
23rd Meeting of the European Society of Neurology (ENS) 2013.
ENS Abstract 175: Is aging without dementia just a dream?;
ENS Abstract O330: Phenotypic variability of familial and sporadic progranulin p.Gln257ProfsX27 mutation;
ENS Abstract O331: Neuroanatomical correlates of disease progression in a case of nonfluent/agrammatic variant of primary progressive aphasia due to progranulin (GRN) Cys157LysfsX97 mutation;
ENS Abstract P661:Computer-assisted cognitive rehabilitation in stroke and Alzheimer’s disease: pilot study;
ENS Abstract P 670: Cerebrospinal fluid and neuroimaging biomarkers in posterior cortical atrophy
European Neurological Society