Nervous System Part 1

1. Depression

Diksha Bhatla 01 Jan 1970

DEPRESSION 

Depression is a common mental disorder, characterized by sadness, loss of interest or pleasure, feelings of guilt or low self-worth, disturbed sleep or appetite, feelings of tiredness and poor concentration. It can be long lasting or recurrent, substantially impairing a person’s ability to function at work or school, or cope with daily life. There are many different types of depression caused by certain events in life and chemical changes in brain. 

Major depression: Major depression is the presence of depressed mood or loss of pleasure for at least two consecutive weeks along with changes in appetite or weight, changes in sleep pattern, retardation, fatigue, feeling of worthlessness, excessive guilt, difficulty concentrating, and thoughts of suicide and can lead to a variety of emotional and physical problems. 

Chronic major depression: Depressed mood for at least two years along with appetite disturbance, sleep disturbance, fatigue, low self-esteem, poor concentration and difficulty in making decision and feeling of hopelessness. 

Dysthymia (recurrent, mild depression): Dysthymia is a type of chronic “low-grade” depression. More days than not, person feel mildly or moderately depressed, although person may have brief periods of normal mood. 

Seasonal affective disorder (SAD): Some people get depressed in the fall or winter, when overcast days are frequent and sunlight is limited. This type of depression is called seasonal affective disorder (SAD). 

Bipolar disorder: When depression is just one side of the coin, it is bipolar disorder, also known as manic depression and it is characterized by cyclic mood changes. 

Atypical features: An ability to be cheered by happy events, increased appetite, little need for sleep, sensitivity to rejection, and a heavy feeling in arms or legs. 

Mixed features: Simultaneous depression and mania, which includes elevated self-esteem, talking too much, and racing thoughts and ideas. 

Psychotic features: Depression accompanied by delusions or hallucinations, which may involve themes of personal inadequacy or negative themes. 

Catatonia: Include motor activity that involves either uncontrollable and purposeless movement or fixed and inflexible posture. 

Peripartum onset: It occurs during pregnancy or in the weeks or months after delivery. 

Causes 

The causes of depression are not fully understood and may not be down to a single source. Depression is likely to be due to a complex combination of factors that include: 

• Genetics 

• Environmental
• Psychological and social (psychosocial)

Pathophysiology

Deregulation of Serotonin (5HT) and Norepinephrine (NE) in the brain are strongly associated with depression. Deregulation of 5HT and NE in the spinal cord may explain an increased pain perception among depressed patients. Decreased levels of 5HT and NE may explain the presence of both emotional and physical symptoms of depression. 

Serotonin: 

As a neurotransmitter, serotonin helps to relay messages from one area of the brain to another. Because of the widespread distribution of its cells, it is believed to influence a variety of psychological and other body functions. Approximately 40 million brain cells, most are influenced either directly or indirectly by serotonin. 

Serotonin is made via a unique biochemical conversion process. It begins with tryptophan, a building block to proteins. Cells that make serotonin use tryptophan hydroxylase, a chemical reactor which, when combined with tryptophan, forms 5-hydroxytryptamine, otherwise known as serotonin. 

Symptoms 

People with depressive illnesses do not all experience the same symptoms. The severity, frequency and duration of depression depending on the individual’s particular illness. Although depression may occur only one time during life, usually people have multiple episodes of depression. During these episodes, symptoms occur most of the day, nearly every day and may include: 

• Feelings of sadness, emptiness or unhappiness. 

• Angry outbursts, irritability or frustration, even over small matters.
• Loss of interest or pleasure in normal activities, such as sex.
• Sleep disturbances, including insomnia or sleeping too much.
• Tiredness and lack of energy, so that even small tasks take extra effort.

• Changes in appetite often reduced appetite and weight loss, but increased cravings for food and weight gain in some people.
• Anxiety, agitation or restlessness, e.g., excessive worrying, pacing, hand- wringing or an inability to sit still.
• Slowed thinking, speaking or body movements.

Treatments And Drugs 

Numerous depression treatments are available. Medications and psychological counseling (psychotherapy) or other mental health counselor are very effective for most people. 

Medications: Many types of antidepressant medications are available to treat depression, including those below. The more commonly used medications are from the following classes: 

• Selective serotonin reuptake inhibitors (SSRIs): SSRIs include Fluoxetine, Paroxetine, Sertraline, Citalopram and Escitalopram.
• Serotonin-norepinephrine reuptake inhibitors (SNRIs): SNRI medications include Duloxetine, Venlafaxine and Desvenlafaxine.
• Atypical antidepressants: Trazodone and Mirtazapine
• Serotonin modulators.

Older, less commonly used, antidepressants include: 

• Tricyclic antidepressants: Tricyclic antidepressants such as Imipramine and Nortriptyline tend to cause more severe side effects than do newer antidepressants.
 

• Monoamine oxidase inhibitors (MAOIs): Commonly used MAOIs are Tranylcypromine and Phenelzine. Taking MAOIs should avoid or limit certain foods, which can interact with the medication and cause serious health problems.

Psychotherapy: 

Psychotherapy treatment is focused on improving positive changes in depressive patients. There are many specific types of psychotherapy that are used to treat depression. Each works in a slightly different way, but all have been proven to help improve the symptoms of depression. 

• Cognitive-behavioural therapy (CBT): In CBT, the therapist is to identify and reshape the thought and behaviour patterns that contribute to depression. 

• Interpersonal psychotherapy: In interpersonal psychotherapy, focus is on improvement of relationships, the way that depressive patients interact with other people in their life. 

• Family and couples therapy: In family and couples therapy, the therapist shall improve interaction of patient with family members so that depressive patients can work together on the issues that are contributing depression. 

• Problem solving therapy: In problem- solving therapy, the therapist have to develop practical and systematic approach to the problems in life and 

find effective ways to solve them.
• Psychodynamic psychotherapy: In psychodynamic therapy, therapist might explore childhood or historic life events and work to reduce their influence by gaining insight into how they may be shaping current behaviour. 

Prevention 

Avoid alcohol drinking or use of illegal drugs. These substances can make depression worse and might lead to thoughts of suicide. Take medication exactly as instructed. 

There is no sure way to prevent depression. However, the following strategies may help feel better: 

Get more exercise, maintain good sleep habits, seek out activities that bring pleasure, volunteer or get involved in group activities, try to be around people who are caring and positive, intervening with a depressed friend, be empathetic and understanding, avoid critical or shaming statements and challenge expressions of hopelessness 

2. ALZHEIMER'S DISEASE NOTES

Diksha Bhatla 01 Jan 1970

ALZHEIMER'S DISEASE 

Alzheimer’s disease (AD) is a progressive, degenerative disorder that attacks the brain’s nerve cells, or neurons especially in the cerebral cortex, resulting in loss of memory, thinking and language skills, and behavioural changes. A degenerative brain disease of unknown cause that is the most common form of dementia or loss of intellectual function, is generally found among people aged 65 and older. A common form of dementia of unknown cause, begin in late middle age, characterized by progressive memory loss and mental deterioration associated with brain damage. A disease marked by the loss of cognitive ability, generally over a period of 10 to 15 years and associated with the development of abnormal tissues and protein deposits in the cerebral cortex. Alzheimer's disease is a condition in which nerve cells in the brain die, making it difficult for the brain's signals to be transmitted properly. Alzheimer’s symptoms may be hard to distinguish early on. A person with Alzheimer's disease has problems with memory, judgment, and thinking, which makes it hard for the person to work or take part in day-to-day life. The death of the nerve cells occurs gradually over a period of years. 

Causes 

Like all types of dementia, Alzheimer's disease is a neurodegenerative disease which results from a combination of genetic, lifestyle and environmental factors that affect progressive brain cell death over a course of time. 

Although the causes of Alzheimer's are not yet fully understood, its effect on the brain is clear. Alzheimer's disease damages and kills brain cells. A brain affected by Alzheimer's disease has many fewer cells and many fewer connections among surviving cells than does a healthy brain. As more and more brain cells die, Alzheimer's leads to significant brain shrinkage. 

Plaques: These clumps of a protein called β-amyloid may damage and destroy brain cells in several ways, including interfering with cell-to-cell communication. Although the ultimate cause of brain-cell death in Alzheimer's is not known, the collection of β-amyloid on the outside of brain cells is a prime suspect. 

Tangles: Brain cells depend on an internal support and transport system to carry nutrients and other essential materials throughout their long extensions. This system requires the normal structure and functioning of a protein called tau. 

Loss of nerve cell connections: The tangles and plaques cause neurons to lose their connection to one another and die off. 

Types of AD 

Early onset AD: Symptoms appear before age 60. This type is much less common than late onset. However, it tends to get worse quickly. Early onset disease can run in families. Several genes have been identified. 

Late onset AD: This is the most common type. It occurs in people after age 60 and older. It may run in some families, but the role of genes is less clear. 

Symptoms 

In most people with Alzheimer's, the disease progresses slowly, usually over a number of years. Dementia symptoms include difficulty with many areas of mental function, including: Emotional behaviour or personality. 

Common symptoms of Alzheimer's disease include: 

Impaired memory and thinking: The person has difficulty in remembering things or learning new information. In the later stages of the disease, long-term memory loss occurs, the person cannot remember personal information, such as place of birth or occupation, or names of close family members. Forgetting details about current events and forgetting events of own life history. 

Disorientation and confusion: People with Alzheimer's disease may get lost when out on their own and may not be able to remember where they are or how they got there. They may not recognize previously familiar places and situations. They also may not recognize familiar faces or know what time of the day it is, or even what year it is. 

Misplacing items: The person forgets where they put items used every day, such as glasses, a hearing aid, keys etc. The person may also put things in strange places, such as leaving their glasses in the refrigerator. 

Abstract thinking: Difficulty performing tasks that take some thought, but used to come easily, such as balancing a check book, playing complex games (such as bridge), and learning new information or routines. 

Trouble performing familiar tasks: Difficulty in performing basic tasks, such as preparing meals, choosing proper clothing, grooming and driving. Planning for normal day-to-day tasks are also impaired. 

Hallucinations, arguments, striking out, and violent behaviour: The person becomes unusually angry, irritable, restless, or quiet. At times, people with Alzheimer's disease can become confused, paranoid, or fearful. 

Poor or decreased judgment: People with Alzheimer's disease may leave the house on a cold day without a coat or shoes or could go to the store wearing pajamas. 

Treatment 

Although there is no cure, Alzheimer's medications can temporarily slow the worsening of symptoms and improve quality of life for those with Alzheimer's and their caregivers. The U.S. Food and Drug Administration (FDA) has approved five medications (listed below) to treat the symptoms of Alzheimer's disease. 

Exercise: Regular exercise has known benefits for heart health and may also help prevent cognitive decline. Exercise may also help improve mood. 

Nutrition: People with Alzheimer's may forget to eat, lose interest in preparing meals or not eat a healthy combination of foods. They may also forget to drink enough water, leading to dehydration and constipation.  

Prevention 

Although there is no proven way to prevent alzheimer's disease, there are some practices that may be worth incorporating into daily routine, particularly with family history of dementia. 

Consume a low-fat diet, eat cold- water fish (like tuna, salmon and mackerel) rich in omega -3 fatty acids, at least 2 to 3 times per week, reduce intake of linoleic acid found in margarine, butter, and dairy products, increase antioxidants like carotenoids, vitamin E and vitamin C by eating plenty of darkly coloured fruits and vegetables, maintain a normal blood pressure and stay mentally and socially active throughout life.