HUMAN DISEASES (Part 5 of 7)

Non-infectious Nerve Disorders

Neuritis, disease of the nerves causing pain, abnormal circulation, and reflex action; differs from neuralgia because of inflammation; treatment includes heat, proper nutrition, physical therapy, and medication.

Neuritis is the degeneration of one or more nerves. It is often marked by a pins-and-needles feeling, a burning sensation, or a stabbing pain. Neuritis can result from infection, especially of the facial nerve, hard body blows, or bone fracture causing nerve injury.

Everyday hard grasping of tools and activities requiring cramped body positions can also trigger neuritis.

Neuralgia, severe, stabbing pain along course of nerve; not associated with nerve damage; attacks often triggered by infection, malnutrition, chilling, or fatigue; sometimes is symptom of organic disease; trigeminal neuralgia, popularly called tic douloureux, affects main sensory nerve of face and is treated by local anaesthetic or cutting of nerve roots.

Neuralgia is often confused with neuritis but is a distinct problem. Neuralgia is characterized by sudden, sharp bursts of pain along any of the sensory nerves near the body surface.

Sciatica is severe leg pain resulting from an inflamed sciatic nerve or its branches. A ruptured, or "slipped," disk one of the pads between the vertebra of the spine often causes sciatica.

Tics are usually habitual muscle twitches in the face or neck that seem to serve no purpose. A tic is generally intensified by an emotional situation or by fatigue.

Vertigo, a severe form of dizziness resulting from the inability of the body to adapt to abrupt or unexpected motion.

Vertigo is a dizziness or disorientation that occurs when something is wrong with the body's balancing system, part of which is located in the inner ear. The sufferer feels as though he is falling through space.

Parkinson's disease (or paralysis agitans, or Parkinsonism), chronic disorder of nervous system, manifest by tremors and muscle weakness, accompanied by changes in pigmented cells of brain stem; strikes in middle or late life; treated with drugs and sometimes by brain surgery; named for James Parkinson (1755-1824), British physician who identified it in 1817.

Parkinsonism, or Parkinson's disease, is thought to stem from changes in brain chemistry. Victims of the disorder walk with a slow, shuffling gait, have a wide-eyed, unblinking facial look, and experience muscle tremors, or shakes. They also have trouble speaking and swallowing. Parkinsonism can be treated with a drug called levodopa, or L-dopa.

Multiple sclerosis (MS), chronic disease of the nervous system; cause unknown; leads to disturbances of vision, speech, coordination, and bodily functions.

Multiple sclerosis is a slow-developing disease that eventually involves the entire brain and spinal cord. Its cause is not yet known, but the disease eats away the fatty myelin sheath around many nerves. As a result, it interferes with proper nerve-signal transmission to muscles and organs. Muscle control, vision, mental abilities, and many other body functions are eventually impaired. Physical therapy is often required because the limbs of victims become weak and they are easily tired doing ordinary tasks.

Stroke

Stroke (or cardiovascular accident), common term for cerebral thrombosis (a blood clot that interrupts the blood supply of the brain) and for cerebral haemorrhage (a rupture in a blood vessel that allows blood to escape into the brain tissue); both can cause brain damage with resulting paralysis or death.

A stroke, or cardiovascular accident, occurs when blood can no longer nourish brain tissue and key nerve cells are thereby destroyed. A blood clot in one of the brain's blood vessels, haemorrhage from a broken blood vessel there, or hardening of a brain artery can cause a stroke.

Depending upon the brain area affected, a stroke can culminate in loss of limb use particularly the arms speech difficulties, and partial blindness. In time, victims of relatively non severe strokes often regain most or all of the impaired body functions. In more severe cases, extensive physical or speech therapy is needed for partial rehabilitation of the stroke victim.

Epilepsy

Epilepsy, disease of the nervous system, frequently from subtle brain damage, less often from injury; characterized by sudden, recurrent seizures with loss of consciousness and severe convulsions (grand mal), or in mild form by brief blackouts and fainting spells (petit mal).

Epilepsy is a brain disorder in which nerve signals "fire" abnormally and cause convulsive seizures, or alternating muscle contractions and relaxations. Scar tissue in the brain can provoke some seizures. In many cases, however, doctors cannot pinpoint the reason for an epileptic attack. Someone might have a seizure once and never again. If someone has more than one seizure, the second and any that may follow are officially called epileptic attacks.

Doctors generally recognize several types of epilepsy, including grand mal, petit mal, and infantile spasms. A grand mal attack is usually marked by rigidly contracted muscles, loss of consciousness, and collapse. The attack may last from two to five minutes, followed by deep sleep.

A petit mal attack usually comes as a lapse of awareness for less than a minute. The victim then resumes whatever activity he was engaged in before the attack without realizing anything out of the ordinary took place. Infants under the age of three sometimes have infantile spasms during which sharp muscle contractions force the body to jackknife for a few seconds. Anti convulsive drugs are used to treat and prevent all such attacks.

METABOLIC AND DEFICIENCY DISEASES

Disease can sometimes follow from alterations in normal body metabolism caused by deficiencies in diet, hormones, and vitamins. It can also stem from malfunctions in the body's immunity system.

Malnutrition and Vitamin Deficiencies

Malnutrition can be either over nutrition or under nutrition Obesity resulting from overeating can lead to high blood pressure, heart disease, and diabetes. Under eating can stifle the development of body and mind.

Marasmus is the condition that results when a child's diet lacks both total calories and protein. A child with marasmus is always hungry and wastes away. Kwashiorkor is a protein deficiency that saps a child's strength even though his diet contains enough calories. A child with kwashiorkor lacks an appetite and is sullen. Both conditions occur in underdeveloped nations.

Vitamin deficiencies are uncommon among people in the world's richer nations, except in the cases of pregnant women and those who breast-feed their babies. Since ample vitamins are in the general diet in those lands, there is no medical justification for daily doses of multivitamins to stimulate vigour or prevent colds or infections.

Iron, silver-grey, hard, brittle, fusible element that is the cheapest and most used of all metals. In pure form it is very reactive chemically and rapidly corrodes in moist air and warm temperatures. Iron is often alloyed with other metals to make it tough yet malleable. Pig iron is used to produce steel. The use of iron is prehistoric

Properties of Iron

Symbol Fe

Atomic number 26

Atomic weight 55.8

Group in periodic table VIII

Boiling point 4,982 F (2,750 C)

Melting point 2,795 F (1,535 C)

Specific gravity 7.874

Mineral deficiencies can also produce body disorders. Iron is indispensable for the prevention of anaemia Magnesium is a cofactor in many enzymes. Deficiency of it causes dizziness, weakness, and convulsions. Iodine is a major part of the thyroid hormones.

Without it a person can develop a goitre Fluorine is not considered essential, but it plays a great part in minimizing dental caries, or cavities. Trace elements, such as chromium, cobalt, and manganese are also needed for a healthy body.

Hormone Deficiencies

The body's endocrine system produces a variety of hormones. When the endocrine glands are not working properly, certain disease processes can begin.

Abnormal output of growth hormone from the pituitary gland early in life can result in one of two disorders dwarfism if there is too little or gigantism if there is too much. Abnormal output of certain hormones from the adrenal glands causes irregular regulation of the body's water balance and disturbs the normal retention and excretion of salts. Malfunction in sex hormone production can stem sexual activity, as well as produce excessive hair growth and distribution. Malfunction of the thyroid gland affects the rate at which food is burned for energy, causing the metabolic rate to run too fast or too slow for everyday needs. When part of the pancreas breaks down, diabetes develops.

1921: Insulin found to treat diabetes. In 1921, at the University of Toronto, Frederick Grant Banting and Charles H. Best conducted experiments that successfully isolated the hormone insulin. This hormone is used to control the disease diabetes. The name of the hormone is derived from the Latin word for island, insula, because the hormone is produced in the part of the pancreas called the Islets of Langerhans.

Although it had been known for some time that the pancreas made the enzymes responsible for digesting proteins, it had not been possible to isolate insulin. Insulin is a protein and is digested by the enzymes. Banting and Best used animal experiments to extract insulin and demonstrated that it stopped symptoms of diabetes. Commercial production of insulin uses pigs, oxen, and sheep as sources for the hormone.

Diabetes Mellitus

Diabetes mellitus, a fairly common disease, is caused by lack of biologically active insulin, a hormone secreted by the pancreas. Without insulin the body cannot use sugars and starches in the food. It must then rely upon its stored fat for energy. This storehouse is soon exhausted, however, because without insulin the body can no longer make and store fat. In addition, protein is no longer manufactured and the muscle mass of the body dwindles. The effect of growth hormone is reduced too. All this adds up to a rise in the level of blood sugar and increased urination, which, in turn, dehydrates the body and makes the diabetic thirsty. The sufferer loses weight, experiences muscle cramps, and has an itchy skin. If diabetes is not treated, sodium and potassium are lost in the urine and the products of fat breakdown, called ketones, build up in dangerous proportions in the blood.

The blood also becomes increasingly acid and body dehydration reaches a dangerous level.

Finally, the untreated diabetic goes into a potentially fatal coma.

Diabetes is treated by limiting the patient's diet and injecting him with insulin derived from cattle or hog pancreases. This treatment was pioneered by the Canadian physicians Frederick G. Banting and Charles H. Best in the 1920s.

Recently, an oral medication has proved capable of lowering the blood sugar of diabetics who develop a mild form of the disease after they reach adulthood. These tablets do not contain insulin but are helpful as long as the pancreas of the diabetic still produces some insulin.

Long-term diabetes is often associated with blood vessel degeneration. When this complication occurs, the diabetic can suffer heart disease, stroke, eye haemorrhage and blindness, kidney failure, gangrene of the feet, and serious neuritis.

The normal blood-sugar level ranges between 60 and 100 milligrams per 100 cubic centimetres of blood. It rises slightly higher after a meal. When the level falls below normal, a person has hypoglycaemia and may develop headache, irritability, sweatiness, and other symptoms. Later, the patient has trouble keeping balance, speaks incoherently, and may even become violent or act listless and withdrawn. Finally, the hypoglycaemic person falls into a coma and may have convulsions.

A diabetic may experience hypoglycaemia when he gets an excessive dose of insulin or oral medication. Hypoglycaemia can also result from diseases of the adrenal, pituitary, and pancreas glands, as well as from starvation, liver damage, and alcohol intake. Moreover, some otherwise healthy persons, especially those under too much stress, can suffer mild hypoglycaemia In an emergency, a health care provider may administer sugar, either orally or by intravenous injection. Glucagon, a pancreatic hormone that raises the blood-sugar level, can also be injected. Long-range treatment involves correcting the disorder engendering the low blood sugar. People suffering from hypoglycaemia often respond very favourably to a change in diet that balances sugar and other nutrients.