Everything you need to know about memory disorders.
“Memory is the recollection of previous thoughts or experiences or a person’s ability to save things in his mind and then recall them back when needed.”
These memories are stored in the brain by changing the basic sensitivity of synaptic transmission between neurons as a result of previous neural activity. These facilitated pathways are called memory traces. They are important because once the traces are established; they can be selectively activated by the thinking mind to reproduce the memories. Our brain plays a vital role in the memory process. For example, the hippocampus promotes memory storage.
Some unfortunate people suffer from such damage that they not even lost their memories but also find it difficult to recall them back. There have been various memory disorders. They may be mild to moderate or severe. They depend on which level an injury has occurred. Certain diseases predispose a person to memory dysfunction.
A person can suffer from memory disorders. Most of the time memory loss occurs after severe injury to the brain which can either be complete or partial. Memory loss is found in old age too but not so severe. Many diseases have the ability to cause memory disorders. These include Huntington’s disease, Alzheimer’s Disease, Parkinsonism, Korsakoff syndrome, etc. Other disorders include dementia, amnesia, etc.
Injury or trauma to the head is the leading cause of memory disorders. Injury to the brain leads to tissue displacement, disruption of vascular channels, subsequent hemorrhage, and edema. This damage impairs memory functions and causes a person to lose memory either transient or permanent. A person is unable to recall what happened to him. If the lesion is in the hippocampus, some degree of retrograde amnesia occurs in which a person fails to recall memories from the past and its lesion can also lead to anterograde amnesia in which people are unable to establish new long-term memories of those types of information that are the basis of intelligence.
Diseases like Alzheimer’s lead to memory loss and mostly this disease occurs at a late age. This is a degenerative disease that results in the formation of plaques in brain areas and the cortex becomes atrophic. This disease is characterized by dementia in which intellectual functions of the brain are disturbed. It widely affects thinking, talking, judgment and memory. The loss of neurons in the limbic pathway that drives the memory process leads to memory loss.
Parkinsonism also leads to memory disorders. Her movements are abnormal and are difficult to perform so the highest degree of mental effort is required.
In the case of Korsakoff syndrome which is due to thiamine deficiency in chronic alcohol habitual, the significant loss of brain function seemed. It is characterized by dysfunction of the cerebellum and loss of coordination as well as abnormal eye movement. Mental status is also altered and impaired. A person remains confused and disorientated. This is a permanent type of disease in which a person becomes apathetic.
But such patients should not be regarded as insane. They should be treated with love and care. This thing has proved marked changes in such persons and they can be better with your good treatment.
These are some memory disorders but they can be medically treated now up to a certain level that allows the patient and his family to live well.
We see that one person who was fit got into an accident and loosed his previous memory. Then we see people who are apparently well but showing progressive memory loss. What are the reasons behind this memory loss?
In case of an accident due to severe trauma to the brain, loss of brain functions occur which leads to loss of memory. It can be temporary or it can be permanent depending upon the level of injury and severity of the injury.
We know that some memories last for only a few seconds while others last for hours, days, or years. So we classify memory into three types:
- Short-term memory
- Intermediate-term memory
- Long-term memory.
They are also frequently divided according to the type of information that is stored into two more types:
Declarative memory: It is the memory of various details of integrated thoughts e.g. memory of important experiences
Skill memory: it is associated with motor activities of the person’s body such as the skill developed for learning to drive, hitting a football, etc.
Progressive loss of memory is due to certain diseases. These diseases produce degenerative changes in the brain which affect areas of the brain processing memory and result in a slow loss of memory. Many such diseases have been known these days. Some are Creutzfeldt-Jakob disease, Alzheimer’s disease, alcoholism, pick disease, dementia, HIV, brain tumor and Parkinson’s disease, etc. These diseases result in slow memory loss. Many diseases can cause transient memory loss these are meningitis, stroke due to hypertension, drug abuse, viral infection mostly West Nile virus, malnutrition, certain medicines, disorders, or depression.
Symptoms may vary from mild to severe loss. A person forgets his colleagues’ names, names of his family members, important dates, normal activities which he used to do like driving, office work or cooking, etc. In severe form, a person forgets his own name, address, or family member’s. There is the loss of skill memory as well as declarative memory too. Such persons are mostly shown less alertness and poor response in many activities. Sometimes a person finds it difficult to speak and he mixes up the words and finds it difficult to make the simplest decision.
It has been seen that when damages occur to specific areas of the brain where memory is being processed like the hippocampus, frontal lobes, temporal lobe, and cerebral cortex, memory loss results. These areas store old and new memories.
Treatment entirely depends on the condition and severity of the memory loss. If memory loss is due to some acute diseases, they should be treated first. If it occurs due to some slow and progressive disease, these diseases should be treated to make them further slow so that a person can do his routine work normally. A person should be given multivitamins and natural herbs to sharpen his mind. There is no particular treatment for memory loss. Family support along with complete mental ease can be helpful to the person. He should be allowed to do less mental work, allowing him to take proper sleep and full moral support.
Improve Your Memory:
You can sharpen your memory by simply doing this activity. At night when you go to bed, on lying down try to remember the things and activities you have done throughout the day. At the start, you will find it difficult to remember but do it regularly at night before going to sleep. In this way, you will start remembering things and this will improve your memory a lot.
Mild Cognitive Impairment
“Cognition means the thinking processes of the brain, utilizing both sensory inputs to the brain plus information already stored in the brain.”
Most of our motor actions occur as a result of thoughts generated in the mind. Due to some loss in brain function, this mild cognitive impairment occurs. It is a less severe form of memory disorder. Here no dementia occurs although it may lead to significant changes in memory function. But such patients can perform their daily routine works well without any hazards. There is no impairment in their thinking process or way of talking. They can perform many jobs requiring skills but they tend to forget things or mix up different things together. Mild cognitive impairment is thought to be a boundary line between normal aging and dementia. There is a risk of Alzheimer’s disease with this disorder.
Signs and Symptoms
A person with this disease is characterized by forgetfulness, he tends to tell the same thing again and again and asks the same questions many times. He does not show interest in activities and conversations. He can not initiate anything, he fails to follow different tasks, and he shows poor judgment along with signs of depression and irritability. He feels frustrated and disguises his forgetfulness by laughing and joking. Patients with mild cognitive impairment may also tend to isolate themselves.
A patient’s brain with a mild cognitive impairment may show diffuse amyloid in the cortex region as well as numerous neurofibrillary tangles in the medial temporal lobe like that of Alzheimer but this disease is a bit different from Alzheimer’s disease. There may be a decreased flow of blood to the brain causing stroke and this condition of cognitive impairment. There may see Lewy bodies of Parkinson’s disease. The Lewy bodies are actually clumps of proteins. On MRI an important area of the brain hippocampus may show atrophy or shrinkage and ventricles seem to be enlarged.
A laboratory test for Diagnosis
As there is no particular test to make diagnose this disease so it requires a complete history of a patient along with an examination especially neuropsychological tests should be performed. Other includes complete blood tests as well as other baseline tests. MRI (magnetic resonance imaging) should be done to see the damaged area of the brain. MRI technique is best in telling the progressive loss of grey matter in the brain as a result of this disease.
There is no specific treatment to control or cure this disease but the use of the drug in Alzheimer’s disease is found beneficial here. These are indirect-acting cholinergic agonists especially galantamine, tacrine, donepezil, and rivastigmine. These drugs can delay the progression of the disease but none can stop its progression. Patients with this disease should be treated with love and care by their families. The family should try to be patient and supportive toward those patients.
Lifestyles have a great impact on our brains. Smoking, alcoholism, lack of physical activity, and sluggishness all lead to many other diseases as well as damage to the brain. Other risk factors include increasing age, diabetes, depression, hypertension, hypercholesterolemia, and mutation of a gene that causes Alzheimer’s.
Dementia: “It is a term in which mind has reached a certain, usually normal or acceptable stage of development and then shows signs of deterioration.”
Dementia manifests itself as a decline in the intellectual function of memory, comprehension, reasoning ability, and emotional changes in the life of the patient.
There are three principal forms. We will discuss dementia’s signs and symptoms under these forms.
- Organic dementia
- Senile dementia
- Dementia paralytica or GPI
In all these conditions gross limitation of mental capacity is a late symptom and the early changes, as a rule, are slight. The first indication of this disease may come from a person’s inconsistent behavior detected by his near ones in different spheres of activity.
Organic Dementia – In this condition impairment of the mental faculties occurs due to some lesion of the brain either localized or diffuse. Symptoms: The early stage may be manifested by restlessness and irritability with delirium, excitement, or depression. These usually finish soon and a progressive mental deterioration sets in, with marked loss of memory and confusion about time and place, mistakes as to the identity, and general childishness.
Senile Dementia – This form of dementia is caused by the onset of old age and cerebral arteriosclerosis.
Signs and Symptoms: There is progressive mental deterioration that sets in. The patient loses his memory, behaves silly, becomes childish, and sometimes is perverted in his behavior. In this disease delusions also occur and mostly a patient relates these delusions to his security in later life, with a result he becomes suspicious all the time and even animose towards those members of the family who provide him love, care, support, and comfort.
Dementia Paralytica or GPI: Signs and symptoms: In the early stages, the patient shows a loss of interest in his daily life affairs and becomes negligent and apathetic. There is also blunting of the moral sense with the result that he may micturate in public or commit petty theft or other immoral act. There is a loss of control of sex instinct and that may lead him to expose his genitals in the public or he may assault young girls. In later stages, impulsive outbursts of violence may also take place.
Dementia occurs when there is some damage to certain areas of the brain. These damages may result from a number of diseases and injuries. One of the most important diseases is Alzheimer’s disease, others are multiple sclerosis, Parkinson’s disease, Huntington’s disease, stroke, progressive supranuclear palsy, thiamine deficiency, chronic drug and alcohol abuse, and due to some viral infections of the brain.
All forms of dementia show memory disorders as well as important cognitive function deterioration.
There are no such particular tests done to make a diagnosis of dementia. Complete history and examination are helpful along with a CT scan or MRI, which can tell about the damaged area of the brain.
This includes treating those diseases which have led to this condition. Certain medication is also helpful like mood stabilizers, antipsychotics, stimulants, and some anxiolytics drugs. Also, some brain supplements are good to prevent brain diseases.
Alzheimer’s disease is “a premature aging of the brain, usually beginning in the mid-adult life and progressing rapidly to extreme loss of mental powers.”
Alzheimer’s Disease is a degenerative disease of the brain and memory disorder occurring in the middle to late life but an early manifestation of the disease is now well recognized. This disease affects more than five million people in the United States, resulting in over 100,000 deaths per annum. The risk of the disease increases sharply with age.
The cause of this disease is unknown, but there is evidence of genetic predisposition. Many abnormal genes have been found, each of which leads to similar clinical and pathological features, with only variations in the age of onset and the rate of progression to suggest that there are pathogenetic mechanisms. Some cases of familial Alzheimer’s disease have been shown to have mutations in App, presenilin 1, and presenilin 2 genes.
Sign and Symptoms
Early memory loss, a disintegration of personality, complete disorientation, deterioration in speech, visuospatial deficits, and restlessness are common signs and clinical features. In the late stages, the patient may become mute, incontinent, fragile, bedridden, and usually dies of some other diseases.
On a microscopic level, changes occur eventually throughout the cerebral cortex, but to begin with, certain regions of the brain are particularly involved. The early region is the hippocampus, the entorhinal cortex, and the associated areas of the cerebral cortex. The plaques are formed from the accumulation of several proteins around the beta-amyloid.
Within the center of each plaque is an extracellular collection of degenerating nervous tissue and is surrounded by the rim of large abnormal neuronal processes which are presynaptic terminals filled with an excess of intracellular neurofibrils that are tangled and twisted resulting in the formation of neurofibrillary tangles.
These neurofibrillary tangles are an aggregation of the microtubular protein tau, which is hypophosphorylated. There also seemed to be a marked loss of acetyltransferase which is the biosynthetic enzyme for acetylcholine in the areas of the cortex in which senile plaques occur.
This is thought to be due to the loss of ascending projection fibers instead of a loss of cortical cells. Due to these cellular changes, the affected neuron dies. Thus, there is an accumulation of beta-amyloid peptides in the brain.
At present, there are no such clinical tests available for making the definitive diagnosis of Alzheimer’s disease. Reliance is placed on taking a history carefully and carrying out various neurologic and psychiatric examinations at different intervals of time. In this way, other reasons for dementia can be excluded. Changes in the level of the amyloid peptide or tau in the serum or cerebrospinal fluid may be helpful. MRI or CT scans are also used and they check the abnormalities in the medial part of the temporal lobe which occur in this disease. In advanced cases, a thin atrophied cortex and dilated lateral ventricles may also be found. Positron Emission tomography also gives evidence of diminished cortical metabolism.
Cholinesterase inhibitors like tacrine, donepezil, and rivastigmine are helpful in patients with this disease. These drugs result in an increase in acetylcholine at the site of disease where there is a deficiency of neurotransmitters.
The patient with this disease requires continuous care within a few years after the disease begins.