Diagnostics

PROCTOSCOPY Proctoscopy is an examination of the rectum using a special metal scope called a proctoscope. The rectum is the final portion of the large intestine. It is the 8-inch muscular tube-like section that leads to the anus, the opening of the intestine out of the body. Waste “bowel movements” and gas pass out of the body through the anus. Why is this test done? A proctoscopy is mainly performed to detect and assess diseases of the rectum or anus. How is proctoscopy performed? This test usually is done in the doctor’s office but can also be done in the operating room by a colorectal surgeon. You will be asked to remove your clothing below the waist and lie on your side on a table. The doctor will gently insert a gloved finger into your anus to check for tenderness or blockage caused by a mass lesion. The lubricated proctoscope is then carefully inserted into the rectum. Air is gently pumped in to distend the rectum, and you may feel some fullness and a need to pass stool. The doctor also may use special instruments to remove polyps or a sample of tissue (biopsy) for further testing. When the doctor finishes examining your rectum, he or she will gently withdraw the scope. Most patients do not require anesthesia for this procedure. You may feel some pressure or cramping while the scope is in place, but you should not feel any pain. It is not unusual to feel and hear some air escaping during this procedure. This is normal and expected, and you should not be embarrassed. If you continue to have cramps after the procedure, passing gas may help. Walking around the room after the test may help you to pass the gas. The proctoscopy test usually takes from five to 15 minutes. You will usually be asked to use an enema (medication inserted into the rectum in order to cleanse the bowel) the night before or be given one in the office just before the test. There may be no special preparation at all. Be sure to check with your doctor for specific instructions before your test. Pres-test:

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Talk with your health professional to find out if you need to stop taking some medicines, such as warfarin, before the test.

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Talk with your health professional to find out if you need to take antibiotics before the test, especially if you have a heart murmur, an artificial heart valve, or an artificial implant (such as a replacement joint).

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Tell your health professional if you have been diagnosed with peritonitis, diverticulitis, or toxic megacolon or if you have had recent bowel surgery.

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The preparation for these tests usually involves a thorough cleaning of the lower colon, because it must be completely clear of stool (feces). Even a small amount of fecal material can affect the accuracy of the test.

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You may be instructed to follow a liquid diet for 1 to 2 days before the test. But do not drink red food items such as red juice or red Jell-O.

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You may be instructed to not eat for up to 12 hours before the test.

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You may need to have an enema the night before the test and another enema an hour before the examination.

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You may not need special preparation, especially if you have watery or bloody diarrhea.

Intra-test: You will usually lie on your left side during the test. You may also be asked to kneel on the table with your bottom raised in the air. Once you are in position: •

Your health professional will gently insert a gloved finger into your anus to check for tenderness or blockage. For men, your health professional will also check the condition of the prostate gland.

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The lubricated scope is then inserted. The scope is moved slowly forward into the rectum and lower colon. During a sigmoidoscopy, puffs of air sometimes are blown through the scope to open the colon so that your health professional can see more clearly.

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Suction may be used to remove watery stool, enema liquid, mucus, or blood through the scope.

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Once your health professional has moved the scope forward as far as possible, it is slowly withdrawn while tissue is carefully inspected.

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Your health professional may also insert tiny instruments (forceps, loops, swabs) through the scope to collect tissue samples (biopsy) or to remove growths. Tissue samples may be sent to a laboratory for examination. After the scope is removed, your anal area will be cleaned with tissues. If you are having cramps, passing gas may help relieve them. The entire examination usually takes 5 to 15 minutes, slightly longer if tissue samples are taken or if polyps are removed. If you received a sedative during the test, do not drive, operate machinery, or sign legal documents for 24 hours after the test. Arrange to have someone drive you home after the test. After the test you may resume your regular diet, unless your health professional gives you other directions. Be sure to drink plenty of liquids to replace those you have lost during the preparation for the sigmoidoscopy.

How It Feels: An anoscopy, proctoscopy, and sigmoidoscopy examination can be embarrassing and uncomfortable. You may have cramping, a feeling of pressure or bloating, or feel a brief, sharp pain when the scope is moved forward or when air is blown into your colon. The removal of tissue samples (biopsy) from the colon does not cause discomfort. A local anesthetic is used when a biopsy of the anal area is done. Your anus may be sore for a few days. You may have mild gas pains and may need to pass some gas after the procedure. Walking may help relieve the gas pains. If a biopsy was done or a polyp removed, you may have traces of blood in your stool for a few days. Risk: There is very little risk of complications from having an anoscopy, proctoscopy, or sigmoidoscopy. •

There is a slight chance of piercing the colon (perforation) or causing severe bleeding by damaging the wall of the colon. However, these problems are rare.

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There is also a slight chance of a colon infection (very rare). Call your health professional immediately if you have:

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Heavy rectal bleeding.

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Severe abdominal pain.

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A fever.

Results: Anoscopy, proctoscopy, and sigmoidoscopy tests allow your health professional to look at the inner lining of your anus, rectum, and the lower part of the large intestine (colon). Your health professional should be able to discuss some of the findings with you immediately after the test. Lab results (such as from a biopsy) may take several days. Anoscopy, proctoscopy, and sigmoidoscopy Normal:•

The lining of the colon appears smooth and pink, with numerous folds.

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No abnormal growths, pouches, bleeding, or inflammation is present.

Abnormal: Some of the more common abnormal findings include: •

Hemorrhoids, which are the most common cause of blood in the stool.

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Colon polyps.

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Cancer in the colon.

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A sore (ulcer).

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Pouches in the wall of the colon (diverticulosis).

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Redness and swelling of the lining of the colon (colitis).

Your health professional will discuss any significant abnormal results with you in relation to your symptoms and past health. What Affects the Test Factors that can interfere with your test or the accuracy of the results include: •

Stool in the colon or rectum.

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The structure of the colon, such as a colon that has many turns.

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A barium enema done within a week before sigmoidoscopy.

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Rectal bleeding.

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Drinking red fluids or eating red gelatin. This can change the color of secretions in the colon and may be mistaken for blood. What To Think About

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Follow-up tests, such as colonoscopy, may be needed after sigmoidoscopy. A colonoscopy may also be needed to examine the upper section of the colon if growths were seen during sigmoidoscopy. For more information, see the medical test Colonoscopy.

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In some cases, the sigmoidoscope may be attached to a video monitor and a recording device that lets your health professional see the inside the colon and record the findings.

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Most medical experts recommend colon cancer screening beginning at age 50 for people who have an average risk and earlier for those who have an increased risk for colon cancer, such as those with a family history of colon cancer. Talk with your health professional about which colon cancer screening test is best for you.

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You may not be able to have this test if you have peritonitis, diverticulitis, toxic megacolon, or if you have had recent bowel surgery.

VISUAL EVOKED RESPONSE An evoked potential test measures the time it takes for nerves to respond to stimulation. The size of the response is also measured. Nerves from different areas of the body may be tested. Types of responses are: •

Visual evoked response or potential (VER or VEP), which is when the eyes are stimulated by looking at a test pattern.

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Auditory brain stem evoked response or potential (ABER or ABEP), which is when hearing is stimulated by listening to a test tone.

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Somatosensory evoked response or potential (SSER or SSEP), which is when the nerves of the arms and legs are stimulated by an electrical pulse. Each type of response is recorded from brain waves by using electrodes taped to the head. The visual evoked response (VER) is the most commonly used evoked potential test in the diagnosis of multiple sclerosis (MS). Conducting gel and electrodes are applied to the scalp. The location will depend on the type of response being recorded. For example, when VERs are recorded, the electrodes are applied to the rear (occipital region) of the scalp over the brain areas that register visual stimuli. Stimuli are delivered:

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For VER by a strobe light or a screen with a checkerboard pattern.

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For ABER by clicking noises or a tone sent through earphones.

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For SSER by an electrical pulse at the wrist or knee. This pulse is a mild electrical shock. Responses from the electrodes are recorded. The time between the stimulation and the response is called the latency, which indicates the speed at which the nerves pass a signal. Why It Is Done This test may be used when MS is suspected and a neurological examination alone does not provide enough evidence. For a clear diagnosis of MS, the doctor has to find evidence that multiple parts of the central nervous system are affected. When there are symptoms clearly caused by MS lesions of the spine but no visual symptoms, the visual response may be tested anyway. Abnormal results in such cases mean that there are also areas of damage (MS lesions) on the brain.

Results Findings of this test may include the following. Normal The time between the stimulation and the nerve's response is within the normal range.

Abnormal Some people who are free from symptoms in the nerve area tested will still have abnormal responses in that area. Abnormal response times can also be associated with other neurological diseases or with damaged optic nerves and eyes. What To Think About An evoked potential test typically takes half an hour or longer to do.

ELECTROENCEPHALOGRAM An EEG, or electroencephalogram, is a test that can help diagnose epilepsy. During an EEG, the electrical signals of the brain are recorded. This electrical activity is detected by electrodes, or sensors, placed on the patient's scalp and transmitted to a polygraph that records the activity. How It Works Electrical signals produced by the brain neurons are picked up by the electrodes and transmitted to a polygraph, where they produce separate graphs on moving paper using an ink writing pen or on a computer screen. How to Prepare To prepare for your EEG you should: •

Discuss any medications you are taking with your physician prior to your procedure.

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Wash your hair the night before the test. Do not use hair cream, oils or spray afterward. What Happens During the EEG? You lie down on the examining table or bed while about 20 electrodes are attached to your scalp. You are asked to relax and lie first with your eyes open, then later with them closed. You may be asked to breathe deeply and rapidly or to stare at a flashing light - both of these activities produce changes in the brainwave patterns. If you are prone to seizures, it is rare that you may experience one during the test. If you are being evaluated for a sleep disorder, EEG may be performed continuously during the night while you are asleep. Such a recording, which may involve an evaluation of other body functions during sleep, such as respiration and pulse, is referred to as polysomnography. What Happens After the Test? The electrodes are removed and the glue that held them in place is washed away with acetone. You may have to use additional acetone at home to completely remove the glue. Unless you are actively having seizures or are restricted by your physician, you may drive home. If the EEG was performed overnight, you should arrange to have someone drive you home. If you stopped taking anticonvulsant drugs for the EEG, you can usually start taking them again.

A neurologist examines the EEG recording for abnormalities in the brain-wave pattern, which may reflect diseases of the nervous system.

MAGNETIC RESONANCE IMAGING

MRI is a test that produces very clear pictures of the human body without the use of X-rays. It uses a large magnet, radio waves and a computer to produce these images. MRI can often detect damaged areas in the brain or spinal cord that would be missed by other imaging techniques such as a CAT scan. Indications: •

To detect MS. MRI is considered the best test to help diagnose MS. However, 5% of people with MS do not have abnormalities detected on MRI, thus a "negative" scan does not completely rule out MS. In addition, some common changes of aging may look like MS on a MRI.

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To track the progress of disease. Although they aren't widely needed, sometimes someone with MS will get repeat scans to determine how fast the disease is progressing. Is the MRI Examination Safe? Yes. The MRI examination poses no risk to the average person if appropriate safety guidelines are followed. Many people who have had heart surgery and people with the following medical devices can be safely examined with MRI:

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Artificial joints

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Staples

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Many cardiac valve replacements (check with your doctor)

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Disconnected medication pumps

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Vena cava filters

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Brain shunt tubes for hydrocephalus Some conditions may make an MRI examination inadvisable. Tell your doctor if you have any of the following conditions:

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Heart pacemaker

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Cerebral aneurysm clip (metal clip on a blood vessel in the brain)

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Pregnancy

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Implanted insulin pump (for treatment of diabetes), narcotics pump (for pain medication), or implanted nerve stimulators ("TENS") for back pain

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Metal in the eye or eye socket

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Cochlear (ear) implant for hearing impairment

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Implanted spine stabilization rods

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Severe lung disease (such as tracheomalacia or bronchopulmonary dysplasia)

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Gastroesophageal reflux (a common disease that causes heartburn)

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Weigh more than 300 pounds

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Not able to lie on back for 30 to 60 minutes

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Claustrophobia (fear of closed or narrow spaces) How Long Does the MRI Exam Take? Allow two hours for your MRI exam. In most cases, the procedure takes 40 to 80 minutes; during that time, several dozen images may be taken. What Happens Before the Exam? Personal items such as your watch, wallet (including any credit cards with magnetic strips that can be erased by the magnet) and jewelry should be left at home if possible or removed prior to the MRI scan. Secured lockers are available to store personal possessions. What Happens During the Exam? You may be asked to wear a hospital gown during the MRI scan. As the MRI scan begins, you will hear the equipment making a muffled thumping sound that will last for several minutes. Other than that sound, you should experience no unusual sensations during the scanning. Certain MRI exams require an injection of a contrast material. This helps identify certain anatomic structures on the scan images. Feel free to ask questions and tell the technologist or doctor if you have any concerns. What Happens After the Exam? Your doctor will discuss the test results with you. Generally, you can resume your usual activities immediately.