Memory loss can be caused by many things.
Alzheimer's Disease is an illness which can cause mild to severe memory loss.
Alzheimer's disease (AD), a neurodegenerative disorder, is the most common cause of dementia and characterised clinically by progressive intellectual deterioration together with declining activities of daily living and neuropsychiatric symptoms or behavioral changes. The most striking early symptom is memory loss (amnesia), usually manifest as minor forgetfulness that becomes steadily more dense with illness progression, with relative preservation of older memories. As the disorder progresses, cognitive (intellectual) impairment extends to the domains of language (aphasia), coordinated movement (apraxia), recognition (agnosia) and those functions (such as decision-making and planning) closely related to the frontal lobe of the brain, reflecting extension of the underlying pathological process. This consists principally of neuronal (cell) loss (or atrophy), together with deposition of amyloid plaques and neurofibrillary tangles. Genetic factors are known to be important, and polymorphisms (variations) in three different autosomal dominant genes - Presenilin 1, Presenilin 2, and A-Beta - have been identified that account for a small number of cases of familial, early-onset AD. For late onset AD (LOAD), only one susceptibility gene has so far been identitified - the epsilon 4 allele of the APOE gene. Age of onset itself has a heritability of around 40%.
Parkinson's Disease is a genetic defect, which can result in memory loss.
Parkinson's disease (PD; paralysis agitans) is a neurodegenerative disease of the substantia nigra (an area in the basal ganglia of the brain). The disease was first discovered and its symptoms documented in 1817 (An Essay on the Shaking Palsy) by the British physician Dr. James Parkinson; the associated biochemical changes in the brain of patients were identified in the 1960s. Some genes were identified only recently; others remain unknown.
The disease involves a progressive movement disorder of the extrapyramidal system, which controls and adjusts communication between neurons in the brain and muscles in the human body. It also commonly involves depression and disturbances of sensory systems.
In the United States, the prevalence of Parkinson's disease is 1 per 625 people, though this increases with age, as indicated by the mean onset of 55 years of age. Symptoms usually begin in the upper extremity, and are usually unilateral (one-sided) or asymmetrical at onset.
Huntington's Disease is another disease which can result in memory loss.
Huntington's disease is inherited in autosomal dominant fashion, meaning that it is a dominant allele. People with Huntington's disease have a 50% chance of passing the disease to each of their children.
Symptoms of the disorder include loss of cognitive ability (thinking, speaking), changes in personality, jerking movements of the face and body in general and unsteady walking. These symptoms develop into dementia and cognitive decline (not mental retardation which is an older term referring to the lack of development of mental ability rather than loss of it.) and an advanced form of jerking called chorea, the Greek word for dance.
It usually takes between 10-25 years for the disease to kill someone, and it is invariably fatal. The age of onset of the disease is in the 30s and 40s in most cases.
About 10 percent of Huntington's disease cases occur in people under the age of 20 years and is called juvenile Huntington’s disease. It has an age of onset anywhere between infancy and 20 years of age. The symptoms of juvenile HD are very different from those of adult-onset HD. Individuals with juvenile HD often become stiff or rigid in their movements (instead of having chorea). Any case of HD with an onset before the age of 20 is considered to be the juvenile form.
One interesting fact about the disease is that it contributes to a chemical imbalance that leads many victims to commit suicide. This is also believed in part to be a result of the position in which sufferers find themselves . Another interesting fact about the disease is that it is unusually prevalent in the small Venezuelan fishing village of Barranquitas. Families there have a high presence of the disease and geneticists and doctors view this community as invaluable in the research of the disease.
Symptoms
The symptoms of Huntington’s disease begin insidiously. One-half to three-fourths of the patients present with abnormal movement or rigidity. The remainder of the patients present with mental status changes, such as irritability, moodiness, or antisocial behavior. All of the patients eventually exhibit chorea, which is jerky, random, uncontrollable, rapid movements. Typically, the abnormal movements begin at the extremities and then later progress to involve the trunk.
Other symptoms exhibited by HD patients eventually include slurred speech, speech volume control issues, swallowing disorders (frequently resulting in gagging and/or choking), behavior problems, depression, loss of cognitive abilities, changes in personality, and eventually develop mental deterioration leading to dementia.
Initially, symptoms may present in most any order. Some patients first develop memory or other cognitive difficulties whereas others may first develop chorea or slurred speech. HD patients may initially be highly functional in most capacities while only being diminished in a few.
Approximately 10% of the patients have a juvenile form of Huntington’s disease. Typically, these patients present with muscular rigidity and may later develop a seizure disorder.
Most symptoms tend to worsen in patients when the patient is otherwise ill (e.g. fever, common cold), under stress, or when tired.
Patients with HD, viewed by the lay person, are easily mistaken as being under the influence of alcohol. As a result, HD patients may risk public discrimination due to the presentation of the disease.
Common Neurological Disorders
|
