Medi-Info.COM » Syndromes

Cushing’s Syndrome

admin — Tue, 27 Jul 2010 09:17:12 +0000

- Hypersecretion of glucocorticoids by the adrenal gland, which produces a characteristic constellation of clinical abnormalities, including a moon face and truncal and neck fat pad deposits. It is classified into adrenocorticotropic hormone (ACTH)-dependent (75%) and ACTH-independent (25%) forms. ACTH-dependent forms are also referred to as Cushing’s disease.

Causes and Incidence An ACTH-secreting tumor causes ACTH-dependent Cushing’s syndrome. The tumor may be a pituitary adenoma or an ectopic tumor. The causes of ACTH-independent Cushing’s syndrome include adrenal cancer, adrenal adenoma, micronodular adrenal disease, and factitious or iatrogenic factors. Cushing’s syndrome is most common in women of childbearing age. Iatrogenically induced cases are on the increase.

Disease Process Increased glucocorticoid production is triggered by one of the causal agents. The increased glucocorticoids act as a sort of antianabolic, creating a mediated antagonism in insulin action that results in biochemical energy deprivation. This leads to protein wasting, glucose intolerance, fragility of the vascular system, and reduced effectiveness of the immune system.

Symptoms

General
Muscle weakness, muscle wasting; fragile, thinned skin, purple striae, easy bruising, poor wound healing; moon face, buffalo hump, heavy trunk, thin extremities; back pain, kyphosis; edema, hypertension; mood swings

Children
Precocious puberty; cessation of linear growth

Women
Masculinization: hirsutism, atrophy of breasts, clitoral enlargement, deepening voice, temporal baldness; menstrual irregularities

Men
Feminization: breast enlargement, higher voice, lighter beard; impotence

Potential Complications Potential complications include osteoporosis, pathologic fracture, peptic ulcer, diabetes mellitus, congestive heart failure, and psychoses.

Diagnostic Tests

24-hour urine
Increased urinary free cortisol .250 {micro};g/day

Dexamethasone suppression
Dose of dexamethasone is given at night; positive test result shows reduced plasma cortisol levels next morning (,50% of baseline)

Metyrapone, ACTH stimulation, corticotropin-releasing hormone tests
To determine etiology

Computed tomography, magnetic resonance imaging
To detect adrenal tumors

Treatments Treatment is directed at the underlying cause.

Surgery
Transsphenoidal pituitary resection of the tumor; resection of ectopic tumors, adrenal adenomas, adrenal carcinoma; bilateral adrenalectomy for treatment-resistant pituitary tumor and micronodular adrenal disease.

Drugs
Glucocorticoid and mineralocorticoid lifelong replacement when bilateral adrenalectomy is performed; adrenal inhibitors or ketoconazole used when ectopic tumor cannot be removed; chemotherapy with mitotane for inoperable adrenal carcinomas.

General
Irradiation of the pituitary when surgery cannot be tolerated in treating a pituitary tumor; education that recovery can require a year or longer and that treatment initially makes the patient feel worse.

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Guillain-Barre Syndrome

admin — Sun, 24 Jan 2010 15:21:33 +0000

- A rapidly progressive, acute inflammatory demyelinating polyneuropathy characterized by muscle weakness and paralysis of the extremities and possible respiratory paralysis with abnormal sensation and loss of reflexes.

Causes and Incidence The cause is unknown, but Guillain-Barre syndrome (GBS) is hypothesized to be an autoimmune disorder involving sensitization of peripheral nerve myelin. It is thought to be connected to a previous nonspecific infection and has been associated with inoculation for the swine flu. The incidence of GBS in the United States is 1.7 per 100,000 individuals, and the disorder occurs across age and gender lines.

Disease Process Mononuclear cells infiltrate the peripheral nervous system and set up an inflammatory response in the blood vessels of the cranial and spinal nerves. Demyelination of the peripheral nerves results, causing muscle weakness that begins in the lower extremities and ascends through the body in a symmetric fashion. Respiratory paralysis and facial weakness occur in 30% to 40% of cases. In some cases axonal destruction can cause atrophy in distal muscles and permanent neurologic impairment.

Symptoms The first sign is symmetric muscle weakness in the distal extremities accompanied by paresthesia. This weakness spreads upward to the arms and trunk and then to the face. This ascension usually peaks about 2 weeks after onset. Deep tendon reflexes are absent. Difficulty chewing, swallowing, and speaking may occur, and respiratory paralysis may develop. Bladder atony, postural hypotension, tachycardia, and heart block may be seen. Deep, aching muscle pain is also common.

Potential Complications About 5% of affected individuals die of respiratory failure. Another 10% have permanent residual neurologic deficits. About 90% of survivors make a full recovery, but the recovery time may be as long as 3 years.

Diagnostic Tests The diagnosis is based on the clinical presentation and cerebrospinal fluid samples, which show an increase in protein without an increase in lymphocyte count. Electromyography produces abnormal nerve conductionresults.

Treatments

Surgery
Tracheostomy to provide ventilation in the event of respiratory failure.

Drugs
Immunoglobulin given IV to counteract neurologic defect; narcotic analgesics for pain; prophylactic antiinfectives

Corticosteroids are contraindicated because they worsen the ultimate outcome.

General
Plasma exchange to speed recovery of neurologic deficit; respiratory monitoring and mechanical ventilation for respiratory paralysis; cardiac monitoring for sinus tachycardia, bradyarrhythmia; communication systems if ventilator is used or with facial paralysis; passive range-of-motion exercises; turning to prevent contracture and skin breakdown; rehabilitation to aid neurologic recovery; counseling and support of individual and family for long-term adaptation.

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Irritable Bowel Syndrome

admin — Wed, 06 Jan 2010 15:40:45 +0000

- A noninflammatory motility disorder of the large bowel that alters bowel habits and causes abdominal pain and distention.

Causes and Incidence The cause of irritable bowel syndrome (IBS) is unknown, but it is associated with diet, drugs, toxins, gastrointestinal (GI) hormones, prostaglan-dins, and emotional factors. IBS is a common GI disorder that accounts for about half of all presenting GI complaints in the United States. Women are affected more often than men, and whites and Jews more often than other ethnic groups. All age groups are affected, although the disease is predominant in those under 35 years of age.

Disease Process The pathophysiology of IBS is still unclear. However, two patterns can be identified: one with painful constipation and diarrhea and the other with painless diarrhea. Hypermotility with high-amplitude pressure waves is present in painful IBS, and hypomotility in painless IBS. Myoelectric activity is increased in both patterns, as is contractile activity after meals.

Symptoms The primary symptoms are either painless, urgent diarrhea that occurs after meals, or alternating diarrhea and constipation accompanied by abdominal pain, bloating, flatulence, headache, and fatigue.

Potential Complications IBS is associated with an increased risk of diverticulitis and colon cancer.

Diagnostic Tests A careful history of bowel habits and emotional stimuli, along with a rectal examination that elicits pain in a tender rectum, is important. Manometric studies are done to evaluate electrical response, as are tests to rule out other bowel diseases.

Treatments

Surgery
None.

Drugs
Anticholinergics to reduce pain; bulk-forming agents, antidiarrheal drugs to regulate stool.

General
Highfiber, lowlactose, caffeine-free, low-fat diet; counseling for emotional effects.

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Organic Mental Syndromes (Organic Brain Syndrome)

admin — Mon, 28 Dec 2009 23:49:22 +0000

- A constellation of behavioral signs and symptoms associated with transient or permanent dysfunction of the brain and characterized by impaired intellectual functioning, confusion, and agitation. The most common categories and the ones discussed here are delirium and dementia. Delirium is a reversible, self-limiting condition characterized by a reduced ability to maintain attention to or appropriately shift attention among external stimuli. Dementia is a structurally caused, permanent decline in memory, abstract thinking, and judgment.

Causes and Incidence Delirium most often occurs as a result of withdrawal from intoxication in chronic alcohol and barbiturate abusers and in acute inflammatory disorders such as meningitis and encephalitis. The most common cause of dementia is Alzheimer’s disease; other causes include vascular disease, HIV infection, central nervous system infection, severe head injury, toxic metabolic disturbances, normal pressure hydrocephalus, underlying neurologic disease (parkinsonism, Huntington’s chorea, multiple sclerosis, Pick’s disease), and drug, alcohol, or nutritional abuse. More than 1 million individuals in the United States have dementia, and the elderly are at greatest risk. As the incidence of AIDS increases, the incidence of dementia is expected to increase (an estimated 50% of individuals with end-stage AIDS develop dementia).

Disease Process The pathophysiology of organic mental syndromes is not yet understood. Pathologic changes vary by causation, and in Alzheimer’s-related dementia include atrophy of brain tissue with wide sulci and dilated ventricles, senile plaque formation, and neurofibrillary tangles. Vascular disease–induced dementia is characterized by multiple cerebral infarcts. In AIDS-related dementia, the neurons are infected with HIV, and in hydrocephalus, cerebrospinal fluid circulation and absorption are impeded.

Symptoms

Delirium
Rapid onset; disorientation, including loss of self-recognition in some instances; impaired memory; inability to maintain or shift attention; irritability, agitation, restlessness, hyperactivity; perceptual disturbance, hallucinations, delusions; rambling, fragmented speech; impaired

sleep-wake cycle; lucid intervals, symptoms worse at night; duration about 1 week on average

Dementia
Symptoms vary widely, but the overall picture is a slow, insidious disintegration of personality and intellect with impaired insight and judgment and loss of affect; memory impairment is often the most prominent initial symptom, and others include increasing rigidity of thought; restricted interests; easy distractibility; lack of initiation; speech disturbances; loss of impulse control; change of former traits or exaggeration of those traits (e.g., a neat person becomes slovenly or becomes obsessively preoccupied with orderliness); depression

Potential Complications Delirium may lead to dementia. Dementia (except that caused by trauma) is progressive; the individual eventually becomes totally oblivious to his or her surroundings and ultimately dies. Individuals with dementia are more susceptible to accidents and infection.

Diagnostic Tests The diagnosis of delirium is based on the clinical presentation, particularly the fluctuation of symptoms with periods of lucidity, and a history of one or more etiologic agents. Electroencephalography shows a generalized slowing of background activity. A diagnosis of dementia is warranted with demonstrable impairment of long- and short-term memory and demonstrable disturbances in abstract thinking, judgment, personality, or other higher cortical functions that interfere with social activities and relationships. Attention and arousal tend to be normal in dementia, and manifestations are relatively stable, worsening over time. A definitive diagnosis is available only on autopsy.

Treatments

Surgery
None.

Drugs
Delirium: withdrawal of toxic agents (alcohol, barbiturates) and IV sedation with antianxiety agents for agitation, seizure activity, and tremors Dementia: treatment of underlying disorders; antianxiety agents as disease progresses to relieve anxiety and frustration.

General
Delirium: adequate fluid and electrolytes; seizure precautions; safety precautions (e.g., to prevent wandering, climbing over bedrails); long-term treatment for substance abuse when it is the etiologic agent Dementia: kept in familiar surroundings with minimal environmental changes; use of frequent orientation devices (clocks, calendars, schedules, memory books, name tags); encouragement to do familiar, repetitive routines; safety precautions to prevent wandering; use of adult day care, respite care, or home care to relieve caregiver; family support groups and counseling; prevention of disuse syndrome in end-stage disease.

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Sudden Infant Death Syndrome

admin — Sun, 08 Nov 2009 00:19:10 +0000

- The sudden, unexplained death of an infant under 1 year of age that remains unexplained after a complete postmortem examination.

Causes and Incidence The cause of sudden infant death syndrome (SIDS) is unknown. One widely accepted hypothesis is that it is related to a brainstem abnormality in the neurologic regulation of cardiorespiratory control. Risk factors include prematurity, multiple births, low Apgar scores, central nervous system or respiratory disturbances, poverty, prone sleeping position, overheating, and maternal smoking. SIDS is the most common cause of death in infants 2 weeks to 1 year of age. Distribution is worldwide, and the incidence in the United States is 1.5 in 1,000 live births. More than 7,000 infants die each year in the United States alone. Males are affected more often than females, as are Native Americans and blacks. The incidence is higher in the winter, with January the peak month of occurrence.

Disease Process The pathophysiology is unknown, but pathology results on autopsy are consistent and include findings of pulmonary edema and intrathoracic hemorrhages.

Symptoms The infant is usually found dead in the bed or crib. The bedclothing tends to be disheveled, and the infant is often huddled in a corner face down with the covers over the head. The infant’s hands are often clutching the sheets. Frothy, blood-tinged fluid is in the mouth and nose, and stool and urine fill the diaper.

Potential Complications The syndrome is fatal.

Diagnostic Tests The diagnosis is confirmed by postmortem examination, including examination of the site of death.

Treatments Management focuses on helping the family to cope and on preventing the disorder in infants seen as high risk.

Surgery
None.

Drugs
Respiratory stimulant medications for high-risk infants to prevent SIDS.

General
Intensive psychologic and emotional support of the family from the time of health care contact for at least 1 year, including time to say goodbye to the infant at the emergency center, arranging transportation home, an immediate home visit to allow family to talk and to discuss SIDS (written supplemental material is desirable), support group and counseling referrals, follow-up home visits Preventive measures: identification of infants with high-risk profiles (one or more previous apparently life-threatening events, preterm, SIDS history of two siblings in family, episode of apnea, excessive periodic breathing, central hypoventilation); use of home monitoring devices; nonprone sleeping position for all infants.

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