Introduction to Hydrocephalus

An excessive accumulation of cerebrospinal fluid (CSF) within the ventricular spaces of the brain, hydrocephalus occurs most commonly in neonates. It can also occur in adults as a result of injury or disease. In infants, hydrocephalus enlarges the head, and in both infants and adults, the resulting compression can damage brain tissue.
With early detection and surgical intervention, the prognosis improves but remains guarded. Even after surgery, such complications as developmental delay, impaired motor function, and vision loss can persist. Without surgery, the prognosis is poor: Mortality may result from increased intracranial pressure (ICP) in people of all ages; infants may also die prematurely of infection and malnutrition.
Causes
Hydrocephalus may result from an obstruction in CSF flow (noncommunicating hydrocephalus) or from faulty absorption of CSF (communicating hydrocephalus).
Noncommunicating hydrocephalus
In noncommunicating hydrocephalus, the obstruction occurs most commonly between the third and fourth ventricles, at the aqueduct of Sylvius, but it can also occur at the outlets of the fourth ventricle (foramina of Luschka and Magendie) or, rarely, at the foramen of Monro.
This obstruction may result from faulty fetal development, infection (syphilis, granulomatous diseases, meningitis), a tumor, a cerebral aneurysm, or a blood clot (after intracranial hemorrhage).
Communicating hydrocephalus
In communicating hydrocephalus, faulty absorption of CSF may result from surgery to repair a Continue reading “Introduction to Hydrocephalus”

Anorexia nervosa

The key feature of anorexia nervosa is self-imposed starvation resulting from a distorted body image and an intense and irrational fear of gaining weight, even when the patient is obviously emaciated. An anorexic patient is preoccupied with her body size, describes herself as “fat,” and commonly expresses dissatisfaction with a particular aspect of her physical appearance.
Although the term anorexia suggests that the patient’s weight loss is associated with a loss of appetite, this is rare. Anorexia nervosa and bulimia nervosa can occur simultaneously. With anorexia nervosa, the refusal to eat may be accompanied by compulsive exercising, self-induced vomiting, or abuse of laxatives or diuretics.
Incidence
Anorexia occurs in 5% to 10% of the population; about 95% of those affected are women. This disorder occurs primarily in adolescents and young adults but may also affect older women. The occurrence among males is rising.
Although the prognosis varies, it improves if the patient is diagnosed early or if she wants to overcome the disorder and seeks help voluntarily. Mortality ranges from 5% to 15%—the highest mortality associated with a psychiatric disturbance. One-third of these deaths can be attributed to suicide.
Causes
No one knows what causes anorexia nervosa. Researchers in neuroendocrinology are seeking a physiologic cause but have found nothing definite. Clearly, social attitudes that equate slimness with beauty play some role in provoking this disorder; family factors also are implicated. Most Continue reading “Anorexia nervosa”

Sudden infant death syndrome

A medical mystery of early infancy, sudden infant death syndrome (SIDS)—commonly called crib death—kills apparently healthy infants, usually between ages 1 month and 1 year, for reasons that remain unexplained, even after an autopsy. Typically, parents put the infant to bed and later find him dead, often with no indications of a struggle or distress of any kind.
Some infants may have had signs of a cold, but such symptoms are usually absent. SIDS has occurred throughout history, all over the world, and in all climates.
Causes
SIDS is one of the leading causes of infant death. Most of these deaths occur during the winter, in poor families, and among underweight babies and those born to mothers younger than age 20.
Although infants who die from SIDS often appear healthy, research suggests that many may have had undetected abnormalities, such as an immature respiratory system and respiratory dysfunction. In fact, the current thinking is that SIDS may result from an abnormality in the control of ventilation, which causes prolonged apneic periods with profound hypoxemia and serious cardiac arrhythmias.
Risk factors for the infant include sleeping on the stomach (up to age 4 months), soft bedding in the crib (up to age 1 year), premature birth, having a history of a sibling who had SIDS, and being Continue reading “Sudden infant death syndrome”

Ovarian cysts

Usually ovarian cysts are nonneoplastic sacs on an ovary that contain fluid or semisolid material. Although these cysts are usually small and produce no symptoms, they require thorough investigation as possible sites of malignant change.
Common ovarian cysts include follicular cysts, lutein cysts (granulosa-lutein [corpus luteum] and theca-lutein cysts), and polycystic (or sclerocystic) ovarian disease. Ovarian cysts can develop anytime between puberty and menopause, including during pregnancy. Granulosa-lutein cysts occur infrequently, usually during early pregnancy. The prognosis for nonneoplastic ovarian cysts is excellent.
Causes
Follicular cysts are generally small and arise from follicles that overdistend instead of going through the atretic stage of the menstrual cycle. When such cysts persist into menopause, they secrete excessive amounts of estrogen in response to the hypersecretion of follicle-stimulating hormone and luteinizing hormone that normally occurs during menopause.
Granulosa-lutein cysts, which occur within the corpus luteum, are functional, nonneoplastic enlargements of the ovaries caused by excessive accumulation of blood during the hemorrhagic Continue reading “Ovarian cysts”

Introduction to Septic Arthritis

A medical emergency, septic (infectious) arthritis is caused by bacterial invasion of a joint, resulting in inflammation of the synovial lining. If the organisms enter the joint cavity, effusion and pyogenesis follow, with eventual destruction of bone and cartilage.
Septic arthritis can lead to ankylosis and even fatal septicemia. However, prompt antibiotic therapy and joint aspiration or drainage cures most patients.

Causes
In most cases of septic arthritis, bacteria spread from a primary site of infection, usually in adjacent bone or soft tissue, through the bloodstream to the joint.
Common infecting organisms include four strains of gram-positive cocci—Staphylococcus aureus, Streptococcus pyogenes, Streptococcus pneumoniae, and Streptococcus viridans—and two strains of gram-negative cocci—Neisseria gonorrhoeae and Haemophilus influenzae. Various gram-negative bacilli—Escherichia coli, Salmonella, and Pseudomonas, for example—also cause infection.
Anaerobic organisms such as gram-positive cocci usually infect adults and children older than age 2. H. influenzae most often infects children younger than age 2.

Risk factors
Various factors can predispose a person to septic arthritis. Any concurrent bacterial infection (of the genitourinary or the upper respiratory tract, for example) or serious chronic illness (such as Continue reading “Introduction to Septic Arthritis”

Bulimia nervosa

The essential features of bulimia nervosa include eating binges followed by feelings of guilt, humiliation, and self-deprecation. These feelings cause the patient to engage in self-induced vomiting, the use of laxatives or diuretics, following a strict diet, or fasting to overcome the effects of the binges. Electrolyte imbalances (including metabolic alkalosis, hypochloremia, and hypokalemia) and dehydration can occur, increasing the risk of physical complications.

Bulimia nervosa usually begins in adolescence or early adulthood and can occur simultaneously with anorexia nervosa. It affects nine women for every man affected. Nearly 2% of adult women meet the diagnostic criteria for bulimia nervosa; 5% to 15% have some symptoms of the disorder.

Causes

Bulimia nervosa has no known cause, but psychosocial factors may contribute to its development, including family disturbance or conflict, sexual abuse, maladaptive learned behavior, struggle for control or self-identity, cultural overemphasis on physical appearance, and parental obesity.

Signs and symptoms

The history of a patient with bulimia nervosa is marked by episodes of binge eating that may occur Continue reading “Bulimia nervosa”

Hypothyroidism in adults

Hypothyroidism, a state of low serum thyroid hormone, results from hypothalamic, pituitary, or thyroid insufficiency. The disorder can progress to life-threatening myxedema coma. Hypothyroidism is more prevalent in women than in men.

Causes:

Hypothyroidism results from inadequate production of thyroid hormone, usually because of dysfunction of the thyroid gland due to surgery (thyroidectomy), radiation therapy (particularly with 131I), inflammation, chronic autoimmune thyroiditis (Hashimoto’s disease) or, rarely, conditions such as amyloidosis and sarcoidosis. It may also result from pituitary failure to produce thyroid-stimulating hormone (TSH), hypothalamic failure to produce thyrotropin-releasing hormone, inborn errors of thyroid hormone synthesis, inability to synthesize thyroid hormone because of iodine deficiency (usually dietary), or the use of antithyroid medications such as propylthiouracil.
In patients with hypothyroidism, infection, exposure to cold, and sedatives may precipitate myxedema coma.
Signs and symptoms:
Typically, the early clinical features of hypothyroidism are vague and may include fatigue, forgetfulness, sensitivity to cold, unexplained weight gain, and constipation. As the disorder progresses, characteristic myxedematous signs and symptoms appear, such as decreasing mental stability; dry, flaky, inelastic skin; puffy face, hands, and feet; hoarseness; periorbital edema; Continue reading “Hypothyroidism in adults”

Treatment Options for Thalassemia Major

Before chronic transfusions are initiated, the diagnosis of B0-thalassemia should be confirmed and the parents counseled about this lifelong therapy. Initiating transfusion and chelation therapy can be difficult for parents to face early in their child’s life.

If there is the possibility of a bone marrow transplant, the blood should be negative for cytomegalovirus and irradiated.

Blood Transfusion therapy:

Transfusion therapy promotes general health and well-being and avoids the consequences of ineffective erythropoiesis. A transfusion program generally requires monthly transfusions, with the pretransfusion hemoglobin level >9.5 and <10.5 g/dL. In patients with cardiac disease, higher pretransfusion hemoglobin levels may be beneficial. Some blood centers have donor programs that pair donors and recipients, decreasing the exposure to multiple red cell antigens.

Transfusional hemosiderosis causes many of the complications of thalassemia major. Accurate assessment of excessive iron stores is essential to optimal therapy. The serum ferritin level is useful in assessing iron balance trends, but does not accurately predict quantitative iron stores. Undertreatment or overtreatment of presumed excessive iron stores can Continue reading “Treatment Options for Thalassemia Major”

Introduction to Liver Abscess

Liver AbscessA liver abscess occurs when bacteria or protozoa destroy hepatic tissue, producing a cavity, which fills with infectious organisms, liquefied liver cells, and leukocytes. Necrotic tissue then walls off the cavity from the rest of the liver.
Liver abscess occurs equally in men and women, usually in those older than age 50. Death occurs in 15% of affected patients despite treatment.
Causes
Underlying causes of liver abscess include benign or malignant biliary obstruction along with cholangitis, extrahepatic abdominal sepsis, and trauma or surgery to the right upper quadrant. Liver abscesses also occur from intra-arterial chemoembolizations or cryosurgery in the liver, which causes necrosis of tumor cells and potential infection.
The method by which bacteria reach the liver reflects the underlying causes.
Biliary tract disease is the most common cause of liver abscess. Liver abscess after intra-abdominal sepsis (such as with diverticulitis) is most likely to be caused by hematogenous spread through the portal bloodstream. Hematogenous spread by hepatic arterial flow may occur in infectious endocarditis. Abscesses arising from hematogenous transmission are usually caused by a single organism; those arising from biliary obstruction, by mixed flora. Patients with metastatic cancer to the liver, diabetes mellitus, or alcoholism are more likely to develop a liver abscess. Continue reading “Introduction to Liver Abscess”

Folic acid deficiency anemia

A common, slowly progressive megaloblastic anemia, folic acid deficiency anemia is most prevalent in infants, adolescents, pregnant and lactating females, alcoholics, elderly people, and people with malignant or intestinal diseases.
Causes
Folic acid deficiency anemia results from a decreased level or lack of folate, a vitamin that’s essential for red blood cell production and maturation. Causes include:
  • alcohol abuse (may suppress metabolic effects of folate)
  • inadequate diet (common in alcoholics, elderly people who live alone, and infants, especially those with infections or diarrhea)
  • impaired absorption (due to intestinal dysfunction from such disorders as celiac disease, tropical sprue, and regional jejunitis and from bowel resection)
  • bacteria competing for available folic acid
  • overcooking, which can destroy a high percentage of folic acids in foods
  • limited storage capacity in infants
  • prolonged drug therapy (with anticonvulsants and estrogens)
  • increased folic acid requirement during pregnancy, during rapid growth in infancy (common because of increased survival rate of preterm infants), during childhood and adolescence (because of general use of folate-poor cow’s milk), and in patients with neoplastic diseases and some skin diseases (chronic exfoliative dermatitis).
Signs and symptoms
Folic acid deficiency anemia gradually produces clinical features that are characteristic of other Continue reading “Folic acid deficiency anemia”