Research

Good News for Sufferers of Alzheimer’s disease

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FDA approves two new treatment medications

Two new types of Alzheimer’s treatment medication have been recently approved by the FDA. The new drugs are memantine and cholinesterase inhibitors. Both work on cognitive dysfunction, which is one of the most debilitating outcomes of the disease.

Alzheimer’s disease and cognitive function

One of the consequences of Alzheimer’s is that brain cells die and the connectors, or synapses, between cells become more damaged as the disease progresses, triggering worsening cognitive functioning. The patient’s ability to learn and remember is severely hampered. Medications currently available are not able to reverse the damage caused by Alzheimer’s, although they do offer hope for calming the symptoms.

Memantine and cholinesterase inhibitors work on the neurotransmitters

Neurotransmitters help neurons communicate. Alzheimer’s disease hinders this process by damaging the synapses. The new drugs address this problem in different ways. Memantine regulates glutamate, a key neurotransmitter that impacts learning and memory. If glutamate attaches to the surface of cells, calcium can enter. When Alzheimer’s disease is present, the amount of calcium that enters the cell reaches a level that intensifies the cell damage. Memantine works to decrease the calcium entering the cell. Cholinesterase inhibitors slow down the process whereby key neurotransmitters are damaged.

Typical Alzheimer’s disease treatment methodology

A treatment protocol is established for the Alzheimer’s patient by the doctor depending upon a number of factors. These include:
• The patient’s medical history and current health assessment
• How far the disease has progressed
• The patient’s ability to tolerate medicines and treatment therapies
• Prognosis for the future
• Preferences of the patient and/or guardians

Clinical trials

The only way to determine the effectiveness of new treatment medications is to safely introduce the drugs to people and then document the outcomes. Clinical trials involve a carefully regulated application of new drugs to patients which yields invaluable answers to the questions of a drug’s effectiveness. It is the paramount way for researchers to develop new drug therapies that can reverse, or at least halt, the ravaging effect of Alzheimer’s, and ultimately prevent the disease from occurring.

Michael Mullan: Sex Differences in Alzheimer’s Disease

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Illustration to go with the review of the book, "Brainstorm: The Flaws in the Science of Sex Differences" by Rebecca Jordan-Young
Illustration to go with the review of the book, “Brainstorm: The Flaws in the Science of Sex Differences” by Rebecca Jordan-Young

Article Written by Dr. Michael Mullan

There has long been controversy over whether women or men are most affected by Alzheimer’s disease. Decades ago the perceived wisdom was that Alzheimer’s affected women more than men because women live longer than men and Alzheimer’s is a disease of aging. However, this apparent sex discrimination was challenged in subsequent studies and more recent investigations suggest that women may be at greater risk than men on an age matched basis. However, even this is controversial and may differ between populations.

For instance, some American studies report equal rates between men and women whereas European ones report a sex difference with more women than men being affected. However, several incidence studies looking at new cases of Alzheimer’s suggests that women are more readily affected than men.

Many reasons have been offered as to why there may be sex discrimination by Alzheimer pathology. One idea is that loss of sex hormones after menopause is particularly detrimental to the human brain. It’s known, for instance, that sex hormones can regulate Beta amyloid production. Cell culture studies show that estrogen and testosterone can mitigate the production of amyloid, one of the central features of Alzheimer’s.

Sex hormones may play other roles as well as regulating the amount of amyloid produced. They may have a role for instance in the breakdown of amyloid and the clearance of amyloid by other mechanisms in the brain. It’s also possible that progesterone have a protective role in the brain. Evidence suggests that after difference insults to the brain, progesterone can be protective.

While all of these observations on the sex differences have been very valuable, no therapy has yet emerged based on hormone replacement. In fact, key studies looking at hormone replacement in post-menapausal women have not shown any beneficial reduction in the risk for Alzheimer’s disease. At best, hormone replacement therapy has shown mixed results in relation to any protection against Alzheimer’s disease. Interestingly, any evidence that sex hormones are helpful in Alzheimer’s are restricted to prevention strategies rather than treatment strategies. In other words, it looks as if prolonged exposure to sex hormones may influence the rate of Alzheimer’s disease; but, once the disease is established, sex hormone therapy is not clearly protective.
So, although there is evidence that Alzheimer’s disease does indeed discriminate against women, the underlying causes are still uncertain and simple hormone replacement therapy may not be the best answer. However, more broadly, Alzheimer’s discriminates against both genders once natural hormone levels start to fall in the later decades of life.

Much more work needs to be done to understand these effects and to ask whether any of these findings can be turned into new clinical treatments for the disease.