Brief Summary of Headaches

The most common patient complaint, headache usually occurs as a symptom of an underlying disorder. Ninety percent of all headaches are vascular, muscle contraction, or a combination; 10% are due to underlying intracranial, systemic, or psychological disorders.
Migraine headaches, probably the most intensively studied, are throbbing, vascular headaches that usually begin to appear in childhood or adolescence and recur throughout adulthood. Affecting up to 10% of Americans, they’re more common in females and have a strong familial incidence.
Causes
Most chronic headaches result from tension—muscle contraction—that may be caused by emotional stress, fatigue, menstruation, or environmental stimuli (such as noise, crowds, and bright lights).
Other possible causes include glaucoma; inflammation of the eyes or mucosa of the nasal or paranasal sinuses; diseases of the scalp, teeth, extracranial arteries, or external or middle ear; and muscle spasms of the face, neck, or shoulders.
In addition, headaches may be caused by vasodilators (such as nitrates, alcohol, and histamines), systemic disease, hypoxia, hypertension, head trauma and tumor, intracranial bleeding, abscess, and aneurysm.
Migraine headache
The cause of migraine headache is unknown, but a genetic link has been identified. These headaches are associated with constriction and dilation of intracranial and extracranial arteries initiated by neurons in the brainstem. Certain biochemical abnormalities are thought to occur during a migraine attack. They include local leakage of a vasodilator polypeptide called neurokinin through the dilated arteries as an inflammatory response and a decrease in the plasma level of serotonin.
Foods associated with migraine headache include aged or processed cheese and meats, alcoholic beverages (particularly red wine), food additives (such as monosodium glutamate), chocolate- and caffeine-containing foods, and nuts. Changes in the weather pattern, menstrual cycle fluctuations, sleep pattern changes, and too much or too little exercise as well as glaring lights and fatigue can also trigger a migraine headache. In addition, one of the more common causes of a recurring headache is the rebound effect that occurs when the original treatment used to get rid of the headache triggers the next episode (as with narcotics).
Headache pain
Pain may emanate from the pain-sensitive structures of the skin, scalp, muscles, arteries, and Continue reading “Brief Summary of Headaches”

Brief Summary of Ascariasis

Also known as roundworm infection, ascariasis is caused by the parasitic worm Ascaris lumbricoides. It occurs worldwide but is most common in tropical areas with poor sanitation and in Asia, where farmers use human stool as fertilizer. In the United States, it’s more prevalent in the South, particularly among younger children.
Causes
A. lumbricoides is a large roundworm resembling an earthworm. It’s transmitted to humans by ingestion of soil contaminated with human stool that harbors A. lumbricoides ova. Such ingestion may occur directly (by eating contaminated soil) or indirectly (by eating poorly washed raw vegetables grown in contaminated soil).
Ascariasis never passes directly from person to person. After ingestion, A. lumbricoides ova hatch and release larvae, which penetrate the intestinal wall and reach the lungs through the bloodstream. After about 10 days in pulmonary capillaries and alveoli, the larvae migrate to the bronchioles, bronchi, trachea, and epiglottis. There they’re swallowed and return to the intestine to mature into worms.

Signs and symptoms
Mild intestinal ascariasis may cause only vague stomach discomfort. The first clue may be vomiting a worm or passing a worm in the stool. In established infection, adult worms usually cause no symptoms. Severe disease, however, causes stomach pain, vomiting, restlessness, disturbed sleep and, in extreme cases, intestinal obstruction. Larvae migrating by the lymphatic and the circulatory systems cause various symptoms—for example, when they invade the lungs, pneumonitis may result.

Diagnosis
Microscopic identification of ova in the stool or observation of adult worms, which may be passed rectally or by mouth, confirms the diagnosis. When migrating larvae invade the alveoli, other conclusive tests include X-rays that show characteristic bronchovascular markings: infiltrates, Continue reading “Brief Summary of Ascariasis”

Introduction to Fatty liver

Fatty liverSteatosis, or fatty liver, is the accumulation of triglycerides and other fats in liver cells. In severe fatty liver, fat constitutes as much as 40% of the liver’s weight (as opposed to 5% in a normal liver); the liver’s weight may increase from 3.3 lb (1.5 kg) to as much as 11 lb (5 kg).
Minimal fatty changes are temporary and asymptomatic; severe or persistent changes may cause liver dysfunction. Fatty liver is usually reversible by simply eliminating the cause. This disorder may result in recurrent infection or sudden death from fat emboli in the lungs.
Causes
The most common cause of fatty liver in the United States and Europe is chronic alcoholism, with the severity of liver disease directly related to the amount of alcohol consumed. Other common, non-alcohol-related causes include acquired immunodeficiency syndrome, drug toxicity, and pregnancy.
Other causes include malnutrition (especially protein deficiency), obesity, diabetes mellitus, jejunoileal bypass surgery, Cushing’s syndrome, Reye’s syndrome, carbon tetrachloride intoxication, prolonged total parenteral nutrition (TPN), and DDT poisoning.
Whatever the cause, fatty infiltration of the liver probably results from mobilization of fatty acids from adipose tissues or from altered fat metabolism.

Signs and symptoms
Clinical features of fatty liver vary with the degree of lipid infiltration, and many patients are asymptomatic. The most typical sign is a large, tender liver (hepatomegaly). Common symptoms include right upper quadrant pain (with massive or rapid infiltration), ascites, edema, jaundice, Continue reading “Introduction to Fatty liver”

Placenta previa

With placenta previa, the placenta is implanted in the lower uterine segment, where it encroaches on the internal cervical os. This disorder, one of the most common causes of bleeding during the second half of pregnancy, occurs in approximately 1 in 200 pregnancies, more commonly in multigravidas than in primigravidas. Generally, termination of pregnancy is necessary when placenta previa is diagnosed in the presence of heavy maternal bleeding. Maternal prognosis is good if hemorrhage can be controlled; fetal prognosis depends on gestational age and amount of blood lost.

Causes
With placenta previa, the placenta may cover all (total, complete, or central), part (partial or incomplete), or a fraction (margin or low-lying) of the internal cervical os. (See Three types of placenta previa.) The degree of placenta previa depends largely on the extent of cervical dilation at the time of examination because the dilating cervix gradually uncovers the placenta. Although the specific cause of placenta previa is unknown, factors that may affect the site of the placenta’s attachment to the uterine wall include:
  • defective vascularization of the decidua
  • multiple pregnancy (the placenta requires a larger surface for attachment)
  • previous uterine surgery
  • multiparity
  • advanced maternal age.
With placenta previa, the lower segment of the uterus fails to provide as much nourishment as the fundus. The placenta tends to spread out, seeking the blood supply it needs, and becomes larger and thinner than normal. For unknown reasons, eccentric insertion of the umbilical cord often develops. Hemorrhage occurs as the internal cervical os effaces and dilates, tearing the uterine vessels.

Signs and symptoms
Placenta previa usually produces painless third-trimester bleeding (typically the first complaint). Because of the placenta’s location, various malpresentations occur that interfere with proper descent of the fetal head. (However, the fetus remains active, with good heart tones.) Complications of placenta previa include shock or maternal and fetal death.

Diagnosis

Special diagnostic measures that confirm placenta previa include:
  • transvaginal ultrasound scanning for placental position
  • pelvic examination, performed only immediately before delivery. In most cases, only the cervix is visualized. Continue reading “Placenta previa”

Introduction to Tetanus

Tetanus, also known as lockjaw, is an acute exotoxin-mediated infection caused by the anaerobic, spore-forming, gram-positive bacillus Clostridium tetani. Usually, such infection is systemic; less often, localized.
Tetanus is fatal in up to 60% of nonimmunized persons, usually within 10 days of onset. When symptoms develop within 3 days after exposure, the prognosis is poor.

Causes
Normally, transmission is through a puncture wound that is contaminated by soil, dust, or animal excreta containing C. tetani, or by way of burns and minor wounds. After C. tetani enters the body, it causes local infection and tissue necrosis. It also produces toxins that then enter the bloodstream and lymphatics and eventually spread to central nervous system tissue.
Tetanus occurs worldwide, but it’s more prevalent in agricultural regions and developing countries that lack mass immunization programs. It’s one of the most common causes of neonatal deaths in developing countries, where neonates of unimmunized mothers are delivered under unsterile conditions. In such neonates, the unhealed umbilical cord is the portal of entry.
In America, about 75% of all cases occur between April and September.
Signs and symptoms
The incubation period varies from 3 to 4 weeks in mild tetanus to less than 2 days in severe tetanus. When symptoms occur within 3 days after injury, death is more likely. If tetanus remains localized, signs of onset are spasm and increased muscle tone near the wound.
If tetanus is generalized (systemic), indications include marked muscle hypertonicity, hyperactive deep tendon reflexes, tachycardia, profuse sweating, low-grade fever, and painful, involuntary muscle contractions:
  • neck and facial muscles, especially cheek muscles—locked jaw (trismus) and a grotesque, grinning expression called risus sardonicus
  • somatic muscles—arched-back rigidity (opisthotonos), boardlike abdominal rigidity
  • intermittent tonic convulsions lasting several minutes, which may result in cyanosis and sudden death by asphyxiation.
Despite such pronounced neuromuscular symptoms, cerebral and sensory functions remain normal. Complications include atelectasis, pneumonia, pulmonary emboli, acute gastric ulcers, flexion contractures, and cardiac arrhythmias.
Neonatal tetanus is always generalized. The first clinical sign is difficulty in sucking, which usually Continue reading “Introduction to Tetanus”

Introduction to Chalazion

A common eye disorder, a chalazion is a granulomatous inflammation of a meibomian gland in the upper or lower eyelid. This disorder is characterized by localized swelling and usually develops slowly over several weeks.
A chalazion may become large enough to press on the eyeball, producing astigmatism; a large chalazion seldom subsides spontaneously and may have to be incised and curetted surgically. A person susceptible to developing chalazia may have more than one because the upper and lower eyelids contain many meibomian glands. If a chalazion becomes persistent and chronic, a neoplasm should be ruled out by biopsy.

Causes
Obstruction of the meibomian (sebaceous) gland duct causes a chalazion.
Signs and symptoms
A chalazion occurs as a painless, hard lump that usually points toward the conjunctival side of the eyelid. Eversion of the lid reveals a red elevated area on the conjunctival surface.
Diagnosis
Visual examination and palpation of the eyelid reveal a small bump or nodule. Persistently recurrent chalazia, especially in an adult, necessitate a biopsy to rule out meibomian cancer. Continue reading “Introduction to Chalazion”

Sprains and strains

A sprain is a complete or incomplete tear in the supporting ligaments surrounding a joint that usually follows a sharp twist. A strain is an injury to a muscle or tendinous attachment. Both usually heal without surgical repair.

Causes
Sprains occur when there is trauma to the joint, causing the joint to move in a position it wasn’t intended to move. Strains may be caused by excessive physical effort or activity, improper warming up before an activity, or poor flexibility.
Signs and symptoms
Sprains and strains cause varying signs and symptoms.
Sprains
A sprain causes local pain (especially during joint movement), swelling, loss of mobility (which may not occur until several hours after the injury), and a black-and-blue discoloration from blood extravasating into surrounding tissues. A sprained ankle is the most common joint injury.
Strains
A strain may be acute (an immediate result of vigorous muscle overuse or overstress) or chronic (a result of repeated overuse).
An acute strain causes a sharp, transient pain (the patient may say he heard a snapping noise) and rapid swelling. When severe pain subsides, the muscle is tender; after several days, ecchymoses appear.
A chronic strain causes stiffness, soreness, and generalized tenderness. These conditions appear several hours after the injury.
Diagnosis
A history of recent injury or chronic overuse, clinical findings, and an X-ray to rule out fractures establish the diagnosis. Continue reading “Sprains and strains”