AD manifests in various ways. The signs and symptoms are specific to each individual and the characteristics of how the dementia develops will be different for each person.
Most patients (85% of cases) present the typical form (amnestic or hippocampus), which starts with the symptom of episodic progressive memory loss in relation to recent events and difficult taking in new information, and thereby losing the ability to adapt to new situations. Discrete constructional apraxia. Loss of fluidity of speech with normal comprehension. Early and persistent depression, anxiety or apathy (most common), with a substantial decline in initiative, motivation and interest, and with indifference and passivity.
In the mid stages, the disease presents loss of remote memory. Temporal and spatial disorientation. Ideomotor and ideational apraxia occur as well as constructional apraxia. Speech continues to worsen and comprehension issues are added to the loss of fluidity and anomia. Visual and body image agnosia (somatagnosia) develops. The mid stages are when sleep and psychiatric disorders are most evident, including becoming agitated at night, being restless, delirium (being unable to distinguish what is reality: delusional jealousy, confusing TV programmes with real life) and hallucinations (false sensory perceptions: hearing voices, seeing insects).
In the late stages, patients present severe agnosia, a loss of bladder and bowel control, become mute or almost mute, and present motor function alternations such as overall stiffness and a stooped posture. Approximately 10% present epileptic seizures. All patients show obvious weight loss during this final stage.
In around 15% of patients with AD, memory may be relatively preserved until the late stages. These are atypical forms or variants (without memory loss in the early stages) which may present in three forms: with behavioural or personality changes, with visuospatial alterations, or with changes to language as the earliest and predominant symptom of the disease. As it progresses, the other symptoms described as the typical form of the disease also appears. These atypical forms of AD are more common in cases where the onset occurs at a younger age.
Daily activities (DA) are progressively affected: first there is a reduction in work and social activities (advanced daily activities); followed by changes to everyday activities (handling domestic objects, money, cooking, housework), and in the late stages, basic daily activities are affected (washing, dressing, eating, bladder and bowel control). In the final stage, patients enter a vegetative state and die as the result of an intercurrent illness: the time from diagnosis to death is usually around » 5-10 years.
Who is affected by Alzheimer’s disease?
The prevalence and incidence of the disease increases after 65 years of age. It therefore affects 5% of the population over 60, 20% of those over 80 and 30% of those over 90. In Spain there are 800,000 people with the condition. The real figure is undoubtedly much higher, however, as the first symptoms are sometimes difficult to distinguish from those that naturally appear with age. For this reason it is an underdiagnosed disease, with around 1 in 3 people with AD believed to be undiagnosed.
Fewer than 5% of cases of AD are hereditary. This is known as familial or inherited AD and occurs through autosomal dominant inheritance. The clinical picture includes an earlier onset of the condition (before 65 years old) and a faster evolution.
The remaining 95% (sporadic AD) present the combination of risk factors for the development of the disease together with genetic alterations, together making the patient susceptible to the disease.
Apart from genetic factors, other risk factors for developing the disease are: ageing; gender (from 65 it is more common in women); vascular risk factors such as high blood pressure, diabetes or obesity; lifestyle (smoking, alcohol, lack of physical activity, lack of intellectual activity, little social interaction); previous head injuries, and chronic sleep disorders. People with Down syndrome (trisomy 21) have an extra copy of the gene that encodes the amyloid precursor protein (APP) making them more susceptible to AD at a younger age. Chronic sleep problems increase the risk of AD. Interrupted sleep increases levels of the amyloid-beta and tau protein.
Due to the fact that pathological alterations (amyloid deposit following tau) begin in the brain 15-20 years before symptoms appear, there are currently considered to be 3 stages of the disease:
- Dementia caused by Alzheimer’s (cognitive alterations affecting daily activities)
- MCI caused by Alzheimer’s (cognitive alterations not affecting daily activities)
- Preclinical or presymptomatic Alzheimer’s (people with biomarkers (+) but no symptoms: cognitively normal).
Although there is currently no cure for the disease, there are treatments that can delay or slow the progression of the disease for a time, improving quality of life for these people. Drug treatments are: cholinesterase inhibitors (rivastigmine donepezil, galantamine) that act to facilitate cholinergic neurotransmission and are licensed for the symptomatic treatment of light or moderate AD, and memantine, a non-competitive glutamatergic NMDA receptor antagonist, which decreases levels of glutamate (an excitotoxin that destroys neurons when released chronically and in excess) and is licensed for the mid and late stages of the disease.
In addition to these treatments, proper management of lifestyle factors is very important, such as: correcting any hearing loss, reducing smoking and drinking, proper management of blood pressure and diabetes, a balanced diet, avoiding obesity, doing regular physical activity, preserving and encouraging social contact. Together with the above, cognitive stimulation is useful during a large part of the progression of the disease.
There are currently 400 studies assessing the efficacy and safety of different treatments in patients with AD.
Known preventions strategies work on the risk factors for the disease: healthy habits, controlling vascular risks (high blood pressure, diabetes, etc.), a higher level of education, changes to lifestyle (essentially increasing physical activity) giving up toxic habits (smoking and drinking). All of the above can reduce cases of AD by 35-40%, or at least delay its onset.
Education and mental activity stimulate the connections in the brain and increase the cerebral reserve capacity, so it is very important to remain mentally active.
Related departments that treat this disease:
The Dementia Unit in the Neurology department is in charge of diagnosing and looking after patients with Alzheimer’s. The unit includes neurologists with expertise in diagnosing and managing the different pathologies that can occur with dementia (changes to cognitive and behavioural functions that result in changes to daily life) as the main manifestation. Neuropsychologists, nurses and social services and healthcare staff also play a very important role in the Unit.
Other units and departments involved in the diagnosis and monitoring of these patients are: Primary Care, Nuclear Medicine, Neuroradiology, Psychiatry, Pathological Anatomy, Genetics.
Notable professionals at Vall d’Hebron who treat this condition:
The head of the Dementia Unit is Dr José Álvarez Sabin, head of the Neurology Department.
Hospital o serveis complementaris relacionats