Funicular myelosis

Funicular myelosis: description

Funicular myelosis (spinal disease) is a rare disease that affects mainly people between the ages of 50 and 70 years. Characteristic are (reversible) damage to the posterior area of ​​the spinal cord (posterior cord). The spinal cord runs protected in the spinal canal from the tailbone to the head and belongs to the central nervous system.

Funicular myelosis is caused in most cases by a vitamin B12 deficiency (hypovitaminosis). Vitamin B12 (also called cobalamin) has many functions in the body. It is important for the nerve cells, red blood cells as well as the protein and nucleic acid metabolism. The nucleic acids are building blocks of the genome.

Man absorbs vitamin B12 mainly through dairy products, meat, eggs and whole grains. The vitamin can be stored in the body in relatively large quantities and over years. The main memory is in the liver. Funicular myelosis usually occurs when these stores are completely exhausted.

Funicular myelosis: symptoms

Most of the time Funikular Myelosis develops creeping, rarely fast and acutely. First, a vitamin B12 deficiency by an anemia (pernicious anemia) noticeable. In this form of anemia, the red blood cells are enlarged (megaloblastic) and have an increased concentration of the blood pigment hemoglobin (hyperchromic).

Funicular myelosis is a variant-rich disease. Especially affected is the spinal cord, but also the brain (encephalopathy). Damage to the brain is noticeable through cognitive impairment. The mental symptoms range from tiredness to dementia and psychotic symptoms.

Sensitivity disorders on the legs

In 90 percent of the cases, funicular myelosis causes symmetrical and sometimes painful paresthesia, which often starts at the legs. Disturbances of the position, vibration and contact senses such as tingling and ant running are characteristic. In addition, the funicular myelosis may also be accompanied by disorders of temperature and pain sensation. These sensory disturbances result in a gait insecurity (sensitive ataxia). In addition, sufferers tire quickly when walking.

Rarely, a funicular myelosis at an early stage leads to motor failures.

Spastic paralysis

Funicular myelosis progresses, leading to further damage to the spinal cord and brain over time. As a result, the gait disorders become clearer in the further course. Finally, spastic paralysis of the legs and later also the arms are added.

Disturbances of the reflexes

The muscle reflexes may be increased by the funicular myelosis or reduced in the presence of polyneuropathy. Polyneuropathy is a disease characterized by damage to a variety of nerves and can also occur in a funicular myelosis.

At the same time, non-existent reflexes such as the Babinski reflex on the soles of the foot can usually be triggered. This is the case when the funicular myelosis also affects the so-called pyramidal tract. This is an important nerve pathway in the spinal cord that sends signals from the brain to the muscles.

Disorders of bladder, bowel and sexual function

In about a quarter of cases, the funicular myelosis leads to bladder complaints. These include an initially increased urination, which may later develop into incontinence. The function of the rectum can also be disturbed. In some cases, there is also a risk of impotence.

Further consequences of vitamin B12 deficiency

Funicular myelosis and anemia are not the only consequences of vitamin B12 deficiency. In addition, there are also damage to the mucous membranes, which require vitamin B12. Particularly striking is an inflammatory and painful tissue loss on the tongue (Hunter glossitis).

In addition, homocysteinemia can occur: the amino acid homocysteine ​​can not be metabolised due to the vitamin B12 deficiency, which increases its concentration in the blood. This disease leads to some dangerous vascular damage.

Funicular myelosis: causes and risk factors

The funicular myelosis is usually caused by a vitamin B12 deficiency, more rarely by a folic acid deficiency. In isolated cases, a copper deficiency is responsible for the symptoms. In the case of a vitamin B12 deficiency, the blood level of the vitamin is below 150 picograms per milliliter (pg / ml).

Damage in the spinal cord

Funicular myelosis initially affects the posterior region of the spinal cord. In the further course the illness can spread, for example on the so-called Hinterseitenstränge.

The spinal cord consists mainly of the so-called gray matter, the nerve cell bodies and the white matter in which the nerve processes are located. The nerve processes are surrounded by a high-fat envelope (myelin sheath) to improve electrical signal transmission. Funicular myelosis is associated with swelling of these myelin sheaths. The swelling is reversible through early treatment.

However, the envelope can also be damaged as in multiple sclerosis (demyelination). In the course of the nerve lines can be further and irreversible destroyed.

Slow start

A vitamin B12 deficiency and thus a funicular myelosis are usually slow, because the body can store the vitamin in a relatively large amount (up to four milligrams). Since the daily requirement is only a few micrograms, the store can provide sufficient vitamin B12 for years. If a cobalamin deficiency occurs, this can have a variety of causes.

Vitamin B12 deficiency due to lack of intake

Only in rare cases is the diet responsible for the vitamin B12 deficiency. For example, a strictly vegetarian or vegan diet can result in a reduced vitamin B12 level in the blood. In addition, a vitamin B12 deficiency and thus a funicular myelosis in chronic alcohol abuse and anorexia (anorexia nervosa) occur. Even in old age, diet-related vitamin deficiency situations are possible.

Vitamin B12 deficiency due to lack of absorption

Most of the lack of vitamin B12 and thus the funicular myelosis are caused by insufficient intake of vitamin B12 in the gastrointestinal tract. This so-called resorption disorder occurs in 80 percent of cases due to the lack of a transport protein, which is required for the absorption of the vitamin. This protein is called Intrinsic Factor. It binds to vitamin B12 and brings it to special docking sites (receptors) in the small intestine, where the vitamin can be absorbed into the bloodstream.

The intrinsic factor is formed by certain cells of the gastric mucosa and secreted. For some gastrointestinal disorders (like chronic atrophic gastritis) or after Removal of a stomach part is it possible that insufficient intrinsic factor is being produced? Then there is a risk of long-term funicular myelosis.

In addition, the gastric acid secretion is often disturbed: as a result, cobalamin can not be released from the animal proteins of the food to which it is attached. Then it can not be absorbed in blood. This can be done even with years of taking Gastric acid-inhibiting drugs (like omeprazole) happen.

at bowel disease or Partial removal of the small intestine The intake of vitamin B12 may also be disturbed. Possible causes include chronic intestinal inflammation (such as ulcerative colitis), tuberculosis infections, gluten intolerance, amyloidosis and connective tissue diseases.

Vitamin B12 deficiency due to increased consumption

Only in rare cases is an increased vitamin B12 consumption responsible for the funicular myelosis. Thus, during pregnancy and lactation, the need and thus the consumption of cobalamin increases. Even with infectious diseases caused by fungi, bacteria or fish tapeworms may be an increased need for vitamins. The same applies to diseases with a high rate of cell renewal (such as cancer).

Vitamin B12 deficiency due to impaired use

Even with sufficient intake and absorption, a vitamin B12 deficiency can arise, and this when the use of the vitamin is disturbed. This happens, for example, when antibodies to vitamin B12 form, too much nitrous oxide is inhaled (such as in anesthesia) or congenital disorders of vitamin utilization exist. Thus, a congenital defect of the vitamin B12 transport protein transcobalamin leads to absorption and transport disorders with deficiency symptoms, although the blood concentration of the vitamin is normal in many cases.

Folic acid deficiency

In a few cases, funicular myelosis develops as a result of a deficiency of folic acid. This may be due to inadequate intake, impaired absorption, impaired use and increased consumption (as is the lack of cobalamin):

Inadequate intake of folic acid, for example, may be due to chronic alcohol consumption or anorexia. Intestinal uptake may be affected by chronic bowel disease (such as Crohn’s disease, celiac disease), liver cell damage or certain medications (such as oral contraceptives or the analgesic acetylsalicylic acid). The use of folic acid may also be disturbed by certain medications (such as anticancer drugs) or congenital disorders in folic acid metabolism. As with vitamin B12, increased consumption of folic acid is associated with pregnancy and lactation, as well as diseases with a high rate of cell formation (such as cancer).

Funicular myelosis: examinations and diagnosis

The symptoms of a funicular myelosis cause most sufferers to visit the family doctor or neurologist.

Survey of the medical history (medical history)

First, the doctor in a conversation with the patient raises the medical history (anamnesis). He inquires, for example, about the onset, nature and extent of the complaints.

Physical examination

As part of the physical examination, the doctor will examine the various qualities of sensitivity (such as position, contact, vibration, pain and temperature sensation). In addition, the reflexes are checked. The focus of the investigation is usually suspected of having a funicular myelosis, because most of the symptoms are most obvious there.

blood test

Of particular importance for the diagnosis “Funicular myelosis” is the blood test. There are often signs of anemia due to vitamin deficiency anemia. Among other things, the following parameters are important in this context:

• Blood cells: number and appearance are analyzed.
• Vitamin B12
• folic acid
• Holo-Transcobalamin: This is an early marker of vitamin B12 deficiency. A low value indicates that more vitamin B12 is consumed than absorbed.
• Methylmalonic acid: An elevated level of methylmalonic acid indicates a vitamin B12 deficiency.
• Intrinsic factor antibodies: they render the intrinsic factor useless and thus hinder the absorption of vitamin B12.
• Parietal cell antibodies: The parietal cells of the gastric mucosa produce the intrinsic factor. Antibodies to these cells therefore hinder the production of the protein.
• Indirect bilirubin
• cholesterol

Magnetic Resonance Imaging (MRI)

To further analyze the damage to the spinal cord, an image is taken using magnetic resonance imaging (MRI). Characteristic of a funicular myelosis are abnormalities of the posterior (posterior column) and posterior (posterior lateral) region of the spinal cord.

Neurophysiological examinations

Neurophysiological examinations such as electromyography (EMG, measurement of electrical muscle activity) can be performed to further investigate nerve damage caused by funicular myelosis. Funicular myelosis can be associated with polyneuropathy, which can be detected with these examinations.

Schilling test (vitamin B12 absorption test)

Suspected funicular myelosis sometimes involves the Schilling test (Vitamin B12 absorption test). For this, the patient must take radioactively labeled vitamin B12. In the next 24 hours, his urine is collected and analyzed to see how much of the radiolabeled vitamin has been eliminated. If it is less than five percent, this indicates a resorption disorder.

To prevent radiolabeled cobalamin from being stored in the body, unlabeled vitamin B12 is injected into a muscle during the test. It saturates the body tissue with cobalamin.

If the test result speaks for a vitamin B12 absorption disorder, the examination can be repeated slightly differently for a more detailed clarification. In addition to the radioactively labeled cobalamin, the patient then receives Intrinsic Factor, the transport protein of the vitamin. If the excretion of radioactive cobalamin continues to be reduced, the absorption of the vitamin in the small intestine is disturbed. As excretion normalizes, lack of intrinsic factor is the reason for decreased vitamin intake.

The use of the Schilling test in suspected funicular myelosis is controversial and is sometimes considered superfluous.

sternal

To further investigate anemia, the doctor can perform a so-called neural puncture. To do this, he will use a fine needle to remove some bone marrow from the patient’s breastbone for analysis in the laboratory.

Clarification of gastritis

Pernicious anemia, such as a vitamin B12 deficiency, can cause chronic gastritis. This causes digestive problems and in turn vitamin deficiencies, as not enough hydrochloric acid is secreted for digestion in the stomach (“histamine refractory anacidity”). A gastritis should therefore be examined by a gastroenterologist.

Exclusion of other diseases

Funicular myelosis is similar to a number of other diseases with its symptoms, which must be taken into account when making a diagnosis. The most important alternative diagnosis is multiple sclerosis. Other so-called differential diagnoses include spinal cord inflammation (myelitis), lupus erythematosus, sarcoidosis, muscle diseases (myelopathies) and infectious spinal cord diseases.

Funicular myelosis: treatment

Funicular myelosis progresses steadily without therapy and can leave lasting damage. It should therefore be treated as early as possible. In what way, depends on the cause of the disease.

Funicular myelosis: therapy for vitamin B12 deficiency

The funicular myelosis is usually characterized by the fact that all body stores for vitamin B12 are emptied. The treatment therefore begins with the so-called saturation, that is: In the beginning not only the acute daily requirement of cobalamin (two to five micrograms) must be covered, but also the memory must be refilled. For this purpose, in the first two weeks of therapy usually a milligram of vitamin B12 is injected into the muscle daily.

Subsequently, in the context of long-term therapy, the vitamin deficiency (and thus the funicular myelosis) with once or twice weekly or even once a month cobalamin injections are treated. As an alternative to the injections, there are also vitamin B12 tablets.

Funicular myelosis: therapy for folic acid deficiency

When funicular myelosis is caused by folate deficiency, 15 milligrams of folic acid per day are injected into the muscle. After three to five days can be switched to tablets, which must be taken two to three times a day. After about two weeks, the folic acid storage is usually filled.

In the further course, a balanced diet is often sufficient to maintain a sufficient level of folic acid in the body. Otherwise, or in situations with increased folic acid needs (such as during pregnancy) folic acid can be taken several times a day.

Acute treatment with folic acid and vitamin B12

The combined administration of folic acid and vitamin B12 should only take place in acute cases, as long as the cause of the funicular myelosis is not yet known. Folic acid administration may well ameliorate the symptoms of the blood, but in the case of a vitamin B12 deficiency, it does not prevent the neurological symptoms due to the funicular myelosis. The consequence may be that the administration of folic acid obscures a vitamin B12 deficiency and that the funcular myelosis caused by the cobalamin deficiency is not recognized and treated early.

Funicular myelosis: disease course and prognosis

The early start of treatment is crucial because the funicular myelosis symptoms can only regress if no permanent damage to the nerve cell processes (axons) has occurred.

The symptoms may worsen immediately after the start of treatment. The therapy should be continued anyway.

Almost always the therapy causes at least an improvement of the symptoms within days to weeks. If, however, after three months, no improvement is noticeable, the diagnosis “funicular myelosis” must be checked.

Symptoms that last for months or even years usually do not completely recede. In a not inconsiderable part of Funicular myelosisPatients remain despite successful therapy – often minor – residual symptoms.