All Tests

A urinalysis, also called a urine test, can detect the presence of nitrites in the urine. Normal urine contains chemicals called nitrates. If bacteria enter the urinary tract, nitrates can turn into different, similarly named chemicals called nitrites. Nitrites in urine may be a sign of a urinary tract infection(UTI).

UTIs are one of the most common types of infections, especially in women. Fortunately, most UTIs are not serious and are usually treated with antibiotics. It's important to see your health care provider if you have symptoms of a UTI so you can start treatment right away.

Other names: urine test, urine analysis, microscopic urine analysis, microscopic examination of urine, UA

Nail infection, fungal: The most common fungus infection of the nails is onychomycosis.

Onychomycosis makes the nails look white and opaque, thickened, and brittle. Those at increased risk for developing onychomycosis include:

People with diabetes;
People with disease of the small blood vessels (peripheral vascular disease)
Artificial nails increase the risk for onychomycosis because, when an artificial nail is applied, the nail surface is usually abraded with an emery board damaging it, emery boards can carry infection, and water can collect under the nail creating a moist, warm environment favorable for fungal growth.

Your child may bite his nails for any number of reasons – curiosity, boredom, stress relief, habit, or imitation. Nail-biting is the most common of the so-called "nervous habits," which include thumb-sucking, nose picking, hair twisting or tugging, and teeth grinding.

The nail organ is an integral component of the digital tip. It is a highly versatile tool that protects the fingertip, contributes to tactile sensation by acting as a counterforce to the fingertip pad, and aids in peripheral thermoregulation via glomus bodies in the nail bed and matrix. Because of its form and functionality, abnormalities of the nail unit result in functional and cosmetic issues. The structures that define and produce the nail (nail plate) include the matrix (sterile and germinal), the proximal nail fold, the eponychium, the paronychium, and the hyponychium (see the images below). Collectively, the nail bed (sterile matrix), nail fold, eponychium, paronychium, and hyponychium are referred to as the perionychium.

Nasal congestion or "stuffy nose" occurs when nasal and adjacent tissues and blood vessels become swollen with excess fluid, causing a "stuffy" feeling. Nasal congestion may or may not be accompanied by a nasal discharge or "runny nose."

Nasal congestion usually is just an annoyance for older children and adults. But nasal congestion can be serious for children whose sleep is disturbed by their nasal congestion, or for infants, who might have a hard time feeding as a result.

Stomach queasiness, the urge to vomit. Nausea can be brought on by many causes, including systemic illnesses (such as influenza), medications, pain, and inner ear disease.

Neck pain is the sensation of discomfort in the neck area. Neck pain can result from disorders of any of the structures in the neck, including the cervical vertebrae and intervertebral discs, nerves, muscles, blood vessels, esophagus, larynx, trachea, lymphatic organs, thyroid gland, or parathyroid glands. Neck pain arises from numerous different conditions and is sometimes referred to as cervical pain.

Neuromyelitis optica (NMO) is a central nervous system disorder that primarily affects the eye nerves (optic neuritis) and the spinal cord (myelitis). NMO is also known as neuromyelitis optica spectrum disorder or Devic's disease. It occurs when your body's immune system reacts against its own cells in the central nervous system, mainly in the optic nerves and spinal cord, but sometimes in the brain.

The cause of neuromyelitis optica is usually unknown, although it may sometimes appear after an infection, or it may be associated with another autoimmune condition. Neuromyelitis optica is often misdiagnosed as multiple sclerosis (MS) or perceived as a type of MS, but NMO is a distinct condition.

Neuromyelitis optica may cause blindness in one or both eyes, weakness or paralysis in the legs or arms, painful spasms, loss of sensation, uncontrollable vomiting and hiccups, and bladder or bowel dysfunction from spinal cord damage. Children may experience confusion, seizures or coma with NMO. Neuromyelitis optica flare-ups may be reversible, but can be severe enough to cause permanent visual loss and problems with walking.

Non-Hodgkin's lymphoma, also called non-Hodgkin lymphoma, is cancer that originates in your lymphatic system, the disease-fighting network spread throughout your body. In non-Hodgkin's lymphoma, tumors develop from lymphocytes — a type of white blood cell.

Non-Hodgkin's lymphoma is more common than the other general type of lymphoma — Hodgkin lymphoma.

Many different subtypes of non-Hodgkin's lymphoma exist. The most common non-Hodgkin's lymphoma subtypes include diffuse large B-cell lymphoma and follicular lymphoma

Bleeding from the blood vessels of the nose. The nose is rich in blood vessels and is situated in a vulnerable position on the face. As a result, any trauma to the face can cause bleeding, which may be profuse. Nosebleeds can also occur spontaneously when the nasal membranes dry out, crust, and crack, as is common in dry climates or during winter months, when the air is dry and warm from household heaters. People have increased susceptibility to nosebleeds if they are taking medications that prevent normal blood clotting, such as warfarin (brand name: Coumadin), aspirin, or any anti-inflammatory medication. Other predisposing factors include infection, trauma, allergic and nonallergic rhinitis, hypertension, alcohol abuse, and inherited bleeding problems. Also known as epistaxis.

Numbness in one or both hands describes a loss of sensation or feeling in your hand or fingers. Often, hand numbness may be accompanied by other changes, such as a pins-and-needles sensation, burning or tingling. Your arm, hand or fingers may feel clumsy or weak.

Numbness can occur along a single nerve in one hand, or it may occur symmetrically in both hands.

If you have ever experienced any pain in your neck or back, you’ve probably heard the term “pinched nerve.” In fact, if you have seen a doctor about neck or back pain that did not go away on its own after a few weeks, you’ve probably been diagnosed with a spinal pinched nerve. A pinched nerve is often the result of any type of degenerative spine condition that causes pain and other symptoms. Though this is a common occurrence for most people at some point in their lives, a pinched nerve can be difficult to treat because there are so many potential causes for nerve compression.

The best thing you can do when you start to develop pain that you believe comes from a pinched nerve is to schedule an appointment with your doctor. If diagnosed in time, you may be able to find pain relief with several weeks or months of conservative treatment. Take a moment to read below about what causes a pinched nerve and some warning signs you should be aware of to know whether or not you should see a doctor.

As part of the body’s nervous system, nerves branch out from the brain and spinal cord to carry instructions to every area of the body. Essentially, the nerves are like electrical wires that allow signals to travel from the brain to the spinal cord to the organs and extremities, and back again.

Nerves within the brain and spinal cord are part of the central nervous system, while nerves that run from the spine to other areas of the body are called peripheral nerves. The peripheral nerves originate as nerve roots that exit the spinal cord and then branch off to spread throughout the body. The nerves that travel to muscles allow the muscles to move. Nerves also pass to the skin, providing the ability to feel.

Naturopathic medicine is a distinct primary health care profession, emphasizing prevention, treatment, and optimal

health through the use of therapeutic methods and substances that encourage individuals’ inherent self-healing

process.  The practice of naturopathic medicine includes modern and traditional, scientific, and empirical methods.

Nonalcoholic fatty liver disease is an umbrella term for a range of liver conditions affecting people who drink little to no alcohol. As the name implies, the main characteristic of nonalcoholic fatty liver disease is too much fat stored in liver cells.

Nonalcoholic steatohepatitis, a potentially serious form of the disease, is marked by liver inflammation, which may progress to scarring and irreversible damage. This damage is similar to the damage caused by heavy alcohol use. At its most severe, nonalcoholic steatohepatitis can progress to cirrhosis and liver failureNonalcoholic fatty liver disease is increasingly common around the world, especially in Western nations. In the United States, it is the most common form of chronic liver disease, affecting an estimated 80 to 100 million people.

Nonalcoholic fatty liver disease occurs in every age group but especially in people in their 40s and 50s who are at high risk of heart disease because of such risk factors as obesity and type 2 diabetes. The condition is also closely linked to metabolic syndrome, which is a cluster of abnormalities including increased abdominal fat, poor ability to use the hormone insulin, high blood pressure and high blood levels of triglycerides, a type of fat.

Narcolepsy is a neurological disorder that affects the control of sleep and wakefulness. People with narcolepsy experience excessive daytime sleepiness and intermittent, uncontrollable episodes of falling asleep during the daytime. These sudden sleep attacks may occur during any type of activity at any time of the day.

In a typical sleep cycle, we initially enter the early stages of sleep followed by deeper sleep stages and ultimately (after about 90 minutes) rapid eye movement (REM) sleep. For people suffering from narcolepsy, REM sleep occurs almost immediately in the sleep cycle, as well as periodically during the waking hours. It is in REM sleep that we can experience dreams and muscle paralysis -- which explains some of the symptoms of narcolepsy.

Narcolepsy usually begins between the ages of 15 and 25, but it can become apparent at any age. In many cases, narcolepsy is undiagnosed and, therefore, untreated.

Naegleria (nay-GLEER-e-uh) infection is a rare and usually fatal brain infection caused by an amoeba commonly found in freshwater lakes, rivers and hot springs. Exposure occurs during swimming or other water sports.The amoeba — called Naegleria fowleri — travels up the nose to the brain, where it causes severe damage. Most people who have naegleria infection die within a week.Millions of people are exposed to the amoeba that causes naegleria infection each year, but only a handful of them ever get sick from it. Health officials don't know why some people develop naegleria infection while others don't.Avoiding warm bodies of fresh water and wearing nose clips while in the water may help prevent such infections.

Nasal polyps are soft, painless, noncancerous growths on the lining of your nasal passages or sinuses. They hang down like teardrops or grapes. They result from chronic inflammation due to asthma, recurring infection, allergies, drug sensitivity or certain immune disorders.Small nasal polyps may not cause symptoms. Larger growths or groups of nasal polyps can block your nasal passages or lead to breathing problems, a lost sense of smell and frequent infections.Nasal polyps can affect anyone, but they're more common in adults. Medications can often shrink or eliminate nasal polyps, but surgery is sometimes needed to remove them. Even after successful treatment, nasal polyps often return.

Nasopharyngeal (nay-zoh-fuh-RIN-jee-ul) carcinoma is cancer that occurs in the nasopharynx, which is located behind your nose and above the back of your throat.Nasopharyngeal carcinoma is rare in the United States. In other parts of the world — specifically Southeast Asia — nasopharyngeal carcinoma occurs much more frequently.Nasopharyngeal carcinoma is difficult to detect early. That's probably because the nasopharynx isn't easy to examine and symptoms of nasopharyngeal carcinoma mimic those of other, more-common conditions.Treatment for nasopharyngeal carcinoma usually involves radiation therapy, chemotherapy or a combination of the two. You can work with your doctor to determine the exact approach depending on your particular situation

Nearsightedness (myopia) is a common vision condition in which you can see objects near to you clearly, but objects farther away are blurry.Nearsightedness may develop gradually or rapidly, often worsening during childhood and adolescence. Nearsightedness tends to run in families.A basic eye exam can confirm nearsightedness. You can easily correct the condition with eyeglasses or contact lenses. Another treatment option for nearsightedness is surgery.

Nephrotic syndrome is a kidney disorder that causes your body to excrete too much protein in your urine.Nephrotic syndrome is usually caused by damage to the clusters of small blood vessels in your kidneys that filter waste and excess water from your blood. Nephrotic syndrome causes swelling (edema), particularly in your feet and ankles, and increases the risk of other health problems.Treatment for nephrotic syndrome includes treating the underlying condition that's causing it and taking medications. Nephrotic syndrome can increase your risk of infections and blood clots. Your doctor may recommend medications and dietary changes to prevent these and other complications of nephrotic syndrome.

Neurodermatitis is a skin condition that begins with an itch.The itch can develop anywhere on the surface of the body. Most commonly, though, an itchy patch develops on an arm, leg, or the back of the neck. It also commonly develops in the anal and genital areas. When it appears in the genital area, it often appears on the scrotum or vulva.The itch can be so intense that a person scratches or rubs the itchy patch frequently. The itch can also come and go. For most people, the area feels itchiest when they are relaxing or sleeping. The itch causes people to scratch or rub the area while sleeping — and it can awaken someone from a sound sleep.Quite often, the itch begins during an especially stressful time in someone’s life. Even when the stress subsides, the itch usually continues. Scratching or rubbing can change the appearance of that itchy patch.

Neuroendocrine tumors are abnormal growths that begin in specialized cells called neuroendocrine cells. Neuroendocrine cells have traits similar to nerve cells and to hormone-producing cells.Neuroendocrine tumors are rare and can occur anywhere in the body. Most neuroendocrine tumors occur in the lungs, appendix, small intestine, rectum and pancreas.Neuroendocrine tumors can be noncancerous (benign) or cancerous (malignant).Diagnosis and treatment of neuroendocrine tumors depend on the type of tumor, its location, whether it produces excess hormones, how aggressive it is and whether it has spread to other parts of the body

Neurofibromatosis is a genetic disorder that causes tumors to form on nerve tissue. These tumors can develop anywhere in your nervous system, including your brain, spinal cord and nerves. Neurofibromatosis is usually diagnosed in childhood or early adulthood.The tumors are usually noncancerous (benign), but sometimes can become cancerous (malignant). Symptoms are often mild. However, complications of neurofibromatosis can include hearing loss, learning impairment, heart and blood vessel (cardiovascular) problems, loss of vision, and severe pain.Neurofibromatosis treatment aims to maximize healthy growth and development and to manage complications as soon as they arise. When neurofibromatosis causes large tumors or tumors that press on a nerve, surgery can help ease symptoms. Some people may benefit from other therapies, such as stereotactic radiosurgery or medications to control pain.

The University of Michigan C.S. Mott Children’s Hospital offers one of the nation’s leading treatment programs for infants, children and adolescents with neurological problems (problems affecting the nervous system).Our specialists treat children with brain and neurological conditions with a multidisciplinary approach led by physicians in our department of neurosurgery and our pediatric neurology service. Together with our colleagues in many other pediatric specialties throughout Mott Children’s Hospital, we provide our patients and their families with individualized treatment plans.The pediatric neurology service coordinates medical treatment and therapy for children with neurological conditions

Your doctor can usually diagnose nickel allergy based on your skin's appearance, and a recent exposure to items that may contain nickel.If the cause of your rash isn't apparent, however, your doctor may recommend a patch test (contact hypersensitivity allergy test). He or she may refer you to an allergy specialist (allergist) or a skin specialist (dermatologist) for this test.

Nicotine dependence ― also called tobacco dependence ― is an addiction to tobacco products caused by the drug nicotine. Nicotine dependence means you can't stop using the substance, even though it's causing you harm.Nicotine produces physical and mood-altering effects in your brain that are temporarily pleasing. These effects make you want to use tobacco and lead to dependence. At the same time, stopping tobacco use causes withdrawal symptoms, including irritability and anxiety.While it's the nicotine in tobacco that causes nicotine dependence, the toxic effects of tobacco result from other substances in tobacco. Smokers have much higher rates of heart disease, stroke and cancer than nonsmokers do.Regardless of how long you've smoked, stopping smoking can improve your health. Many effective treatments for nicotine dependence are available to help you manage withdrawal and stop smoking for good. Ask your doctor for hel

Niemann-Pick is a rare, inherited disease that affects the body's ability to metabolize fat (cholesterol and lipids) within cells. These cells malfunction and, over time, die. Niemann-Pick disease can affect the brain, nerves, liver, spleen, bone marrow and, in severe cases, lungs.People with this condition experience symptoms related to progressive loss of function of nerves, the brain and other organs.Niemann-Pick can occur at any age but mainly affects children. The disease has no known cure and is sometimes fatal. Treatment is focused on helping people live with their symptoms.

A nightmare is a disturbing dream associated with negative feelings, such as anxiety or fear that awakens you. Nightmares are common in children, but can happen at any age, and occasional nightmares usually are nothing to worry about.Nightmares may begin in children between 3 and 6 years old and tend to decrease after the age of 10. During the teen and young adult years, girls appear to have nightmares more often than boys do. Some people have them as adults or throughout their lives.Although nightmares are common, nightmare disorder is relatively rare. Nightmare disorder is when nightmares happen often, cause distress, disrupt sleep, cause problems with daytime functioning or create fear of going to sleep.

Nonallergic rhinitis with eosinophilia syndrome (NARES) is a clinical syndrome comprising symptoms consistent with allergic rhinitis in which an absence of atopy has been demonstrated by allergen skin testing, and nasal cytology analysis demonstrates more than 20% eosinophils. Anosmia is a prominent feature not shared with allergic rhinitis. The pathophysiology of NARES is poorly understood, but a key component involves a self-perpetuating, chronic eosinophilic nasal inflammation with development of nasal micropolyposis and polyposis. Mast cells likely play an important role as well. NARES is a risk factor for the development of nasal polyposis and aspirin sensitivity, as well as obstructive sleep apnea. Treatment consists mainly of intranasal corticosteroids with or without the addition of second-generation antihistamines and/or leukotriene-receptor antagonists.

Nonulcer stomach pain is a term for recurring signs and symptoms of indigestion that have no obvious cause. Nonulcer stomach pain is also called functional dyspepsia (dis-PEP-see-uh) or nonulcer dyspepsia.Nonulcer stomach pain is common and can be long lasting. The condition can cause signs and symptoms that resemble those of an ulcer, such as pain or discomfort in your upper abdomen, often accompanied by bloating, belching and nausea.

Noonan syndrome is a genetic disorder that prevents normal development in various parts of the body. A person can be affected by Noonan syndrome in a wide variety of ways. These include unusual facial characteristics, short stature, heart defects, other physical problems and possible developmental delays.Noonan syndrome is caused by a genetic mutation and is acquired when a child inherits a copy of an affected gene from a parent (dominant inheritance). It can also occur as a spontaneous mutation, meaning there's no family history involved.Management of Noonan syndrome focuses on controlling the disorder's symptoms and complications. Growth hormone may be used to treat short stature in some people with Noonan syndrome.

Norovirus infection can cause the sudden onset of severe vomiting and diarrhea. The virus is highly contagious and commonly spread through food or water that is contaminated during preparation or contaminated surfaces. You can also be infected through close contact with an infected person.Diarrhea, abdominal pain and vomiting typically begin 12 to 48 hours after exposure. Norovirus symptoms last one to three days, and most people recover completely without treatment. However, for some people — especially infants, older adults and people with underlying disease — vomiting and diarrhea can be severely dehydrating and require medical attention.Norovirus infection occurs most frequently in closed and crowded environments such as hospitals, nursing homes, child care centers, schools and cruise ships.

Proximal conduction studies by F-wave technique, with conventional distal motor and sensory conduction were performed along the ulnar nerves of 20 patients each with cervical spondylotic radiculopathy and/or myelopathy and with classical motor neurone disease (MND). Such F-wave parameters as shortest F-latency, F-conduction velocity, conduction time and F-ratio were calculated. Twenty-five age- and sex-matched healthy volunteers acted as controls. Proximal slowing associated with sensory conduction abnormalities and normal distal motor conduction favored cervical spondylosis (CS). Distal slowing with a normal proximal motor and sensory conduction was associated with motor neurone disease.

A nerve conduction velocity (NCV) test is used to assess nerve damage and dysfunction. Also known as a nerve conduction study, the procedure measures how quickly electrical signals move through your peripheral nerves.Your peripheral nerves are located outside of your brain and along your spinal cord. These nerves help you control your muscles and experience the senses. Healthy nerves send electrical signals more quickly and with greater strength than damaged nerves.The NVC test helps your doctor differentiate between an injury to the nerve fiber and an injury to the myelin sheath, the protective covering surrounding the nerve. It can also help your doctor tell the difference between a nerve disorder and a condition where a nerve injury has affected the muscles.Making these distinctions is important for proper diagnosis and determining your course of treatment.

A nerve conduction velocity test (NCV) is an electrical test that is used to determine the adequacy of the conduction of the nerve impulse as it courses down a nerve. This test is used to detect signs of nerve injury. In this test, the nerve is electrically stimulated, and the electrical impulse 'down stream' from the stimulus is measured. This is usually done with surface patch electrodes (they are similar to those used for an electrocardiogram) that are placed on the skin over the nerve at various locations. One electrode stimulates the nerve with a very mild electrical impulse. The resulting electrical activity is recorded by the other electrodes. The distance between electrodes and the time it takes for electrical impulses to travel between electrodes are used to calculate the speed of impulse transmission (nerve conduction velocity). A decreased speed of transmission indicates nerve disease or abnormal pressure on the nerve. A nerve conduction velocity test is often done at the same time as an electromyogram (EMG). An EMG is carried out in order to exclude or detect muscle conditions which may be present due to muscular or neurologic disease.

The facial nerve conduction velocity was measured in 30 healthy subjects (60 sides) and in 51 patients with a unilateral Bell's palsy. The normal value was 47.8 +/- 5.1 m/s. Incomplete recovery was common in Bell's palsy when the velocity was below 30 m/s. Mild synkinesis was observed in only one patient when the nerve conduction velocity was above 30 m/s. When the degree of degeneration revealed by electroneuroneography did not exceed 60%, the conduction velocity was in the normal range. For degrees of degeneration in excess of this, the conduction velocity decreased in parallel with the increase in the degree of degeneration.

Eosinophils from nasal smears can be easily distinguished from other granulocytes when submitted to a cytochemical stain. A careful evaluation of the cytological picture may be of diagnostic value in the differentiation of allergy from super imposed infections, or in the attribution of a cause of asthma in children and adults.While it is well documented that the scope of eosinophil stains goes well beyond screening for allergic rhinitis when evaluating body fluids other than those of nasal origin, for compliance purposes with CLIA regulations, the scope of this procedure is restricted to the examination of nasal secretions. This procedure does not apply to the examination of specimens such as urine, stool, or GI secretions.In non-allergic patients experiencing acute infections, few scattered eosinophils may be noted mixed with neutrophils in the resolution stage of the infection. If the number of eosinophils adds up to portray an allergic response, it is recommended follow- up smears are done to achieve distinction between the 2 cases. In the allergic patient, the eosinophils will increment to large numbers whereas neutrophils will disappear (provided a chronic infection does not complicate the picture). Goblet cells, a constant and reliable feature observed in smears from allergy patients even when eosinophils are not demonstrated. These cells are normally not exfoliated; therefore, they will only be apparent if the specimen was obtained by swabbing the mucosa. Goblet cells are “edematous” columnar epithelial cells that are goblet in form. Their cytoplasm is vacuolated and mostly without cilia. Cells eventually rupture leaving the nucleus behind.

Enolase is a glycolytic enzyme that catalyzes the conversion of 2-phosphoglycerate to phosphoenolpyruvate. Enolase exists in the form of several tissue-specific isoenzymes, consisting of homo or heterodimers of 3 different monomer-isoforms (alpha, beta, and gamma). Neuron specific enolase (NSE) is a 78 kD gamma-homodimer and represents the dominant enolase-isoenzyme found in neuronal and neuroendocrine tissues. Its levels in other tissues, except erythrocytes, are negligible. The biological half-life of NSE in body fluids is approximately 24 hours.

Due to this organ-specificity, concentrations of NSE in serum or, more commonly, cerebrospinal fluid (CSF), are often elevated in diseases which result in relative rapid (hours/days to weeks, rather than months to years) neuronal destruction. Measurement of NSE in serum of CSF can therefore assist in the differential diagnosis of a variety of neuron-destructive and neurodegenerative disorders. The most common application is in the differential diagnosis of dementias, where elevated CSF concentrations support the diagnosis of rapidly progressive dementias, such as Creutzfeldt-Jacob Disease. NSE might also have utility as a prognostic marker in neuronal injury. There is, for example, increasing evidence that elevated serum NSE levels correlate with a poor outcome in coma, in particular when caused by hypoxic insult.

NSE is also frequently overexpressed by neural crest-derived tumors. Up to 70% of patients with small cell lung carcinoma (SCLC) have elevated serum NSE concentrations at diagnosis, and approximately 90% of patients with advanced SCLC will have serum levels above the healthy reference range. Other neuroendocrine tumors with frequent expression of NSE include carcinoids (up to 66% of cases), islet cell tumors (typically <40% of cases), and neuroblastoma (exact frequency of NSE expression unknown). NSE levels in NSE-secreting neoplasms correlate with tumor mass and tumor metabolic activity. High levels have therefore some negative prognostic value. Falling or rising levels are often correlated with tumor shrinkage or recurrence, respectively.

Serum neuron-specific enolase (NSE) measurement has its greatest utility in the follow-up of patients with tumors of any type that have been shown to secrete NSE. With successful treatment, serum concentrations should fall with a half-life of approximately 24 hours. Persistent NSE elevations in the absence of other possible causes (see Cautions) suggest persistent tumor. Rising levels indicate tumor spread, or in patients who had previously become NSE negative, recurrence.

In the context of a patient with a lung mass, disseminated malignancy of unknown origin or symptoms suggestive of paraneoplastic disease without identifiable tumor, elevated NSE suggests an underlying small cell lung carcinoma (SCLC).

In patients with suspected carcinoid, islet cell tumor, or neuroblastoma, who have no clear elevations in the primary tumor markers used to diagnose these conditions, an elevated serum NSE level supports the clinical suspicion.

1.Carcinoid: chromogranin A, urinary 5-hydroxyindoleacetic acid, serum/blood 5-hydroxytryptamine

2.Islet cell tumors: variety of peptide and amine-derived hormones, chromogranin A

3.Neuroblastoma: vanillylmandelic acid and homovanillic acid

When considered alongside established outcome predictors of coma, such as Glasgow coma scale and other clinical predictors (papillary light responses, corneal reflexes, motor responses to pain, myoclonus, status epilepticus), electroencephalogram, sensory evoked potentials, measurement of serum NSE concentrations provides additional information. Elevated levels are indicative of a poor outcome. Currently, no established algorithms exist to combine serum NSE concentrations and the various other predictors into a composite score that gives clear predictive outcome information. The NSE measurement therefore needs to be considered in a qualitative or semi-quantitative fashion and carefully weighed against other predictors by a physician experienced in examining and managing coma patients.

All neuron-specific enolase (NSE) test results must be considered in the clinical context, and interferences or artifactual elevations should be suspected if the clinical NSE test results are at odds with the clinical picture or other tests. The laboratory should be contacted for assistance in these situations.

Hemolysis can lead to significant artifactual NSE elevations, since erythrocytes contain NSE.

Hemoglobin concentrations as low as 20 mg/dL were found to have an adverse effect on NSE testing.

Proton pump inhibitor treatment, hemolytic anemia, hepatic failure, and end stage renal failure can also result in artifactual NSE elevations.

Other false positives depend on the treating context. When performing NSE testing for tumor diagnosis or follow-up, epileptic seizure, brain injury, encephalitis, stroke, and rapidly progressive dementia might result in false-positive results. On the other hand, when NSE testing is performed to assist in neurological diagnosis, NSE-secreting tumors can represent a source of false-positive results.

NSE values can vary significantly between methods/assays. Serial follow-up should be performed with the same assay. If assays are changed, patients should be re-baselined. This assay is an immunometric assay, and can therefore in rare situations be affected by false low results in the presence of extremely high NSE concentrations ("hooking") or autoantibodies to NSE, as well as by false results in the presence of heterophile antibodies.

Diagnosis of Niemann-Pick disease begins with a thorough physical exam, which can show an early warning sign such as an enlarged liver or spleen. Your doctor will also take a detailed medical history and discuss symptoms and family health history. Niemann-Pick disease is rare, and its symptoms can be confused with other diseases. Diagnostic techniques depend on the type of Niemann-Pick disease.

1.Type A or B. Using a blood or skin sample (biopsy), experts measure how much sphingomyelinase is in white blood cells to confirm the diagnosis.

2.Type C. Experts take a small sample of skin to test for Niemann-Pick to assess how the cells move and store cholesterol.

Other tests also may be done, such as:

1.Magnetic resonance imaging (MRI). An MRI of the brain may show loss of brain cells. But in the early stages of Niemann-Pick, an MRI may be normal because symptoms typically occur before the loss of brain cells.

2.Eye exam. An eye exam can show signs that may be an indication of Niemann-Pick disease, such as eye movement difficulties.

3.Genetic testing. DNA testing of a blood sample may show the specific abnormal genes that cause Niemann-Pick types A, B and C. DNA tests can show who the carriers are for all types of Niemann-Pick disease if the mutations have been described in the first person identified in a family (the index case).

4.Prenatal testing. Ultrasound can detect the enlarged liver and spleen that's caused by type C. And amniocentesis or chorionic villus sampling may be used to confirm a diagnosis of Niemann-Pick.

No cure exists for Niemann-Pick disease. No effective treatment is available to people with type A or B. For people with mild to moderate type C, a drug called miglustat (Zavesca) may be an option. An international study of 92 people with type C Niemann-Pick showed improved neurological symptoms after taking miglustat regularly for an average of two years.

Physical therapy is an important part of treatment to help maintain mobility as long as possible. People with Niemann-Pick disease need to see their doctors regularly, because the disease progresses and symptoms worsen.