Alzheimer’s disease (AD) is the most common type of dementia, affecting millions of people worldwide. The disease currently has no cure and it worsens as it progresses, eventually leading to death.

AD is typically diagnosed in people over age 65, but some people can experience an early onset, although this is less prevalent. Alzheimer’s disease affected 26.6 million people worldwide as of 2006, and is estimated to affect 1 in 85 people worldwide by 2050.

Signs and Symptoms of Alzheimer’s Disease

AD develops and unfolds differently for each individual, but there are many common symptoms. The early symptoms of this disease are often mistaken as “age-related” issues or manifestations of stress. The most common symptom in the early stages is difficulty in remembering recent events. AD can go undiagnosed for years before becoming fully apparent. As the disease progresses, symptoms can include confusion, aggression, mood swings, irritability, trouble with language, and long-term memory loss. AD patients gradually lose bodily functions, ultimately leading to death. The life expectancy following an AD diagnosis is 7 years on average. There are exceptions, but fewer than three percent of individuals live more than 14 years after diagnosis.

Stages of Alzheimer’s Disease

The course of this degenerative disease is divided into four main stages, with progressive manifestations of cognitive and functional impairments. The four stages of Alzheimer’s disease are as follows:

1. Pre-Dementia

As previously mentioned, the first symptoms of Alzheimer’s disease are often attributed to aging or stress, without suspecting something more serious. According to detailed neuropsychological testing, a person can experience mild cognitive difficulties for up to eight years before fulfilling the clinical criteria for an AD diagnosis. Such early symptoms can affect the more complex daily activities, with memory loss as the most prevalent deficit. At first, memory loss occurs as difficulty in remembering recent events and recently learned facts, as well as an inability to learn new things.

Other symptoms of pre-dementia include subtle issues with the executive functions of attentiveness, planning, abstract thinking, and flexibility. Sufferers also experience impairments in semantic memory, i.e. remembering meanings and concept relationships. Apathy also occurs during this stage, and continues as the most persistent neuropsychiatric symptom throughout the entire disease progression. This pre-dementia stage is also referred to as mild cognitive impairment.

2. The Early Stages

People affected by Alzheimer’s disease experience an increasing, progressive impairment of learning and memory, eventually leading to a definitive diagnosis. A small portion of patients experience difficulties with language, executive functions, perception or execution of movements as the more prominent symptoms rather than memory difficulties. It’s also important to note that AD does not affect all memory capacity equally. New facts and memories are generally more affected than older memories (episodic memory), previously acquired information (semantic memory) and the memory of the body on how to do things, such as using kitchen utensils to eat (implicit memory).

Language problems usually unfold as a shrinking vocabulary and decreased word fluency. In time, these difficulties lead to a general impoverishment of both oral and written language capabilities. Alzheimer’s patients are still able to communicate basic ideas properly at this stage. As the disease progresses, patients may be able to continue performing a number of tasks independently, but may need assistance in more cognitively demanding activities.

3. The Moderate Stage

The disease eventually trumps independence as it progresses, as subjects become unable to perform even the most common tasks of daily living. Speech difficulties become obvious due to the patient’s inability to recall vocabulary, which leads to paraphasias (incorrect word substitutions). Sufferers also progressively lose reading and writing skills during this stage. As time passes and the disease progresses, complex motor sequences become less coordinated, which in turn increases the risk of falling. Memory problems also worsen in this stage, and the patient may fail to recognize even close relatives such as one’s own children. Long-term memory, which was unaffected until this phase, now becomes impaired as well.

In this phase of Alzheimer’s disease, behavioral and neuropsychiatric changes become increasingly prevalent. Common manifestations of such changes include irritability, wandering, labile effect leading to crying, outbursts of aggression, or resistance to care giving and assistance. Roughly 30 percent of AD patients also develop illusionary misidentifications or other delusional symptoms. Patients are no longer aware of their disease process and limitations, and experience increased frustration. All of these symptoms can produce great stress for close relatives and caretakers, and in many cases the person is moved from home care to specialized long-term care facilities.

4. The Advanced Stage

During the advanced and final stage of Alzheimer’s disease, the patient is entirely dependent upon caregivers. Language and vocabulary becomes limited to simple phrases or single words, until the subject eventually loses speech completely. Despite this loss of verbal language abilities, however, patients can often understand and react emotionally. Aggressiveness may still persist, but extreme apathy and exhaustion are more common. Muscle mass and mobility deteriorate to the point that AD patients are bedridden and lose the ability to feed themselves. Alzheimer’s disease is a terminal illness, but the cause of death is generally an external factor such as pneumonia or infection of pressure ulcers, not the disease itself.

Managing and Treating Alzheimer’s Disease

As there is no cure for AD, available treatments aim to offer symptomatic benefit, remaining palliative in nature. Currently there are five medications for treating the cognitive manifestations of the disease: four treatments are acetylcholinesterase inhibitors – tactrine, rivastigmine, gelantamine and donepezil – while the other, memantine, is an NMDA receptor antagonist. None of these drugs or others has shown any indication of delaying or stopping the progression of AD. According to the French Pharmacoeconomic Committee, these medications provide low benefits.

Antipsychotic drugs, meanwhile, are relatively useful in reducing aggression and psychotics associated with Alzheimer’s disease, but they can carry serious side effects such as cerebrovascular events, movement difficulties or cognitive decline.

Caregiving

Alzheimer’s disease gradually renders patients incapable of tending to their needs, which means proper caregiving is crucial and must be carefully managed throughout the course of AD. During the early stages of the disease, for instance, changes to the living environment and lifestyle can increase safety and make things easier for the caretaker. Such modifications may include placing safety locks, adhering to simplified routines, labeling household items and other such measures. Sufferers may no longer be able to feed themselves, and serving food in smaller pieces or pureed may prove helpful. In some cases, feeding tubes are required if the patient experiences difficulties swallowing. Using physical restraints is rarely indicated, regardless of the stage of the disease, but in some cases they are necessary to prevent harm to the AD patient or their caregivers. During the final stages of Alzheimer’s disease, treatment focuses on relieving discomfort until death.