Alzheimer’s disease

Alzheimer’s disease (AD) is a disorder that causes degeneration of the cells in the brain; and it is the major cause of dementia, and is characterized by a decline in thinking ability and independence in personal daily activities. It also causes the brain shrinkage and death. Alzheimer’s disease affects people of age 65 years and above with only 10% of cases occurring in people younger than this.

In AD, plaques are formed in the hippocampus, which helps in encoding memories, and in other areas of the cerebral cortex that are involved in thinking and making decisions.

 

Symptoms of Alzheimer’s disease

Alzheimer’s disease develops in a progressive manner, with the symptoms becoming worse over time. The key features of AD are memory loss, and it is also the first symptoms to develop.

Symptoms of Alzheimer’s disease include:

Memory loss: An AD patient usually has difficulty in taking and processing new information as well as in remembering new information. This leads to:

  • Repeating questions and conversations.
  • Forgetting about events or appointments.
  • They wander about and usually get lost.

Cognitive deficit: The patient experiences difficulty in reasoning, complex task and in judgment.

Problem with recognition: The patient may not be able to recognize faces or objects.

Problems with speaking, reading and writing: The patient would develop difficulties remembering common words, or make more speech, writing and spelling errors.

Personality and behavior changes: The patient may experience certain changes in personality and behavior that include:

  • A loss of interest of motivation in activities they previously enjoyed engaging in.
  • A loss of empathy.
  • The person may become upset, angry or worried often than before.

 

Stages of Alzheimer’s disease

Alzheimer’s disease occurs in stages; from mild to severe cases.

 

Mild Alzheimer’s disease

Patients with mild AD have memory problems and cognitive difficulties, which may also include:

  • Difficulties in handling money or paying bills.
  • Wandering aimlessly and getting lost often.
  • Experiencing behavioral and personality changes.
  • Not being able to perform daily task in shorter time.

 

Moderate AD

In this stage of the disease, the parts of the brain responsible for language, senses, reasoning and consciousness are damaged. The patient finds it difficult recognizing family and friends, lose the ability to learn new things and finds it difficult coping with new the situation. Hallucinations, delusions and paranoid sets in.

 

Severe AD

In this stage, plaques and tangle, which cause brain tissue to shrink substantially, begin to occur.

 

Risk Factors of Alzheimer’s Disease

Age

The older a person becomes, the greater the person’s chances of developing Alzheimer’s disease. Age remains the greatest risk factor of Alzheimer’s disease.

Family history: An individual, whose parents or sibling has the disease, is at a higher risk of developing the disease.

Down syndrome

Many people with Down syndrome develop Alzheimer’s disease later on. This may be associated with having three copies of chromosome 21 and subsequently three copies of the gene for coding the protein that leads to the formation of beta-amyloid. Patients of Down syndrome expresses signs and symptoms of AD 10 to 20 years earlier than in general population.

Head Trauma

Patients who suffer traumatic brain injury (TBI) are at greater risk of developing AD. The more severe the TBI, the greater the chances of developing AD.

 

Treatments of Alzheimer’s disease

Alzheimer’s disease has no cure, currently. But there are however, some available medicines that can temporarily reduce the symptoms. Some of the medications for AD are:

Acetylcholinesterase (AChE) inhibitors

The medicine works by increasing the cellular levels of acetylcholine. Acetylcholine is a brain neurotransmitter that helps nerve cells communicate with each other.

AChE inhibitors include Donepezil, Galantamine and Rivastigmine. They can be prescribed for people with early-to mild-stage AD.

Some side effects associated with these medications include nausea, vomiting and loss of appetite.

Memantine

Memantine works by inhibiting the effects of excess amount of glutamate. It is best used to treat moderate or severe AD and good for those who cannot use AChE inhibitors.

Side effects associated with memantine medication include headache, constipation and dizziness.

 

 

Down syndrome

Down syndrome (DS) is a genetic disorder that  occurs when there is an abnormal cell division, which results in an extra copy of chromosome 21. This extra genetic material is the cause of some developmental changes and physical features of DS.

A baby is typically born with 46 chromosomes, but in babies with Down syndrome, there is an extra copy of the chromosome, chromosome 21. This extra chromosome changes the baby’s body and brain development, which can cause mental and physical challenges for the baby.

People with Down syndrome usually look alike. But despite the similarities in facial appearances, each person has different abilities. They usually have low IQ and are slower to speak than other children.

 

Symptoms of Down syndrome

Down syndrome may be mild, moderate or severe. Some patients are healthy while others may have significant health challenges such as heart defects. Some of the common features of DS include:

  • Small head
  • Short neck
  • Protruding tongue
  • Small ears
  • Poor muscle tone
  • Small hands and feet
  • A single line across the palm of the hand
  • Shorter height as children and adults

 

Types of Down syndrome

There are three types of Down syndrome; nevertheless, without diagnosis it is hard to spot one type from another, because, the physical features remain the same.

Trisomy 21

In this type, which is about 96%, each cell in the body has 3 separate copies of chromosome 21 instead of the normal 2 copies.

Translocation Down syndrome

This can occur when a portion of chromosome 21 becomes translocated onto another chromosome, before or at conception. The child would have the two copies of chromosome 21 and yet another copy of genetic material from chromosome 21 attached to another chromosome.

Translocation Down syndrome accounts for a small percentage of people with DS.

Mosaic Down syndrome

This is a rare form of Down syndrome. In Mosaic DS the child or children have 3 copies of chromosome 21 in some cells and 2 copies in normal cells. They may have fewer features of the condition due to the presence of some normal cells with normal 2 copies of chromosome 21.

 

Is Down syndrome inherited?

Down syndrome actually occurs due to a mistake in cell division during early development of the fetus. However, translocation DS can be passed from parent to child. Nevertheless, only a small percentage of children with translocation DS inherited it from one of their parents.

In this case, one of the parents has some rearranged genetic material from chromosome 21 with no extra genetic material. He or she has no symptoms of DS, but can pass an unbalanced translocation to the child that will result in Down syndrome.

 

Causes and risk factors

The main cause of DS is the extra genetic material of chromosome 21, which leads to the physical features and developmental challenges that is seen among people with DS.

Some of the risk factors are:

Age

The older a woman becomes, the greater the chances of having a child or children with Down syndrome. Women who are 35 years or older are at high risk of having their fetus affected by DS than women who become pregnant at their younger age.

 

Being carriers of genetic translocation for Down syndrome

As indicated above, both parents can pass the genetic translocation for Down syndrome on to their children.

 

Complications associated with Down syndrome

Heart defects: About half of the children with DS have some heart defects, which may be life threatening and may require surgical operations in early infancy.

Dementia: people with Down syndrome are at greater risk of dementia at older age, say 50 and above. Having DS also increases the chances of developing Alzheimer’s disease.

Leukemia: The children have increased risk of leukemia. Other complications include:

  • Obesity
  • Spinal problem
  • Seizures
  • Underactive thyroid

 

Life Expectancy of people with Down syndrome

Unlike in previous ages, life expectancy for people living with DS has dramatically increased. Some people can live for more than 60 years, depending on the severity of health complications.

Management/Treatment

There is no cure for people with DS; but some services can be offered to such people that can improve their physical and intellectual capabilities. These services include speech, occupational and physical therapy.