Funicular Myelosis: Causes, Symptoms & Treatment

Funicular myelosis is a degenerative breakdown of spinal cord structures due to chronic vitamin B12 deficiency. The condition manifests mainly after the fifth decade of life.

What is funicular myelosis?

Funicular myelosis is the degeneration of specific areas of the spinal cord (posterior cord, pyramidal side cords), which is generally due to long-term vitamin B12 deficiency. This leads to a degradation of the medullary sheaths enveloping the nerve cells of the spinal cord. The nerve tracts are exposed and, as with uninsulated electrical wiring, the risk of short circuits is increased. Symptomatic manifestations in funicular myelosis include gait unsteadiness and dizziness due to regression of the posterior cords, insensitivity to the point of paralysis, pain (especially in the legs), rapid fatigue when walking, impotence, urinary retention, and burning of the tongue. In addition, if the optic nerve and/or the nerve pathways leading to the brain are also affected, visual disturbances may occur. In addition, funicular myelosis is associated with pernicious anemia (enlarged erythrocytes with concomitant decrease in concentration).

Causes

Funicular myelosis is due to chronic vitamin B12 deficiency. This may result from inadequate dietary intake on the one hand and malabsorption on the other. The intrinsic factor (glycoprotein) formed in the stomach is required for the absorption of vitamin B12 in the intestine. As a result of chronic gastric diseases (including gastric carcinoma, gastritis), this factor can no longer be produced sufficiently, leading to malabsorption and, in the long term, vitamin B12 deficiency. In addition, infection with the fish tapeworm, various diseases such as tumors (including myeloma, leukemia), pathogenic bacterial colonization of the intestine, Crohn’s disease, ulcerative colitis, sprue or celiac disease, and chronic pancreatic insufficiency can cause vitamin B12 deficiency and thus funicular myelosis. Other risk factors for funicular myelosis include (partial) resection of the stomach, alcoholism, unbalanced diet, and certain medications (including antiepileptic drugs, cytostatic drugs).

Symptoms, complaints, and signs

Funicular myelosis develops very slowly with prolonged vitamin B12 deficiency. Before this, symptoms of hyperchromic anemia first appear, in which the number of erythrocytes decreases but the existing red blood cells have an increased concentration of hemoglobin. Only then does funicular myelosis develop, which can have a wide variety of symptoms. For example, in the majority of cases, sensory disturbances occur in the legs, which can be manifested by tingling, numbness and painful insensations. Sense of position, vibration and touch are disturbed. Furthermore, the sensation of temperature and pain may also be impaired. Due to the sensory disturbances, there is gait instability and rapid fatigue when walking. The progressive destruction of the spinal cord and brain later leads to spastic paralysis in the legs. More rarely, the arms are also affected by the paralyses. At the same time, pyramidal tract signs appear, manifested by abnormal reflexes such as the Babinski reflex. Bladder, bowel and sexual function may also be disturbed. Thus, urinary and fecal incontinence and impotence are possible. Furthermore, damage to the brain also occurs, which can be manifested by cognitive impairment. In addition to severe fatigue, psychotic and dementia symptoms are also observed. If vitamin B12 deficiency is treated early, the symptoms can still be reversed. However, if treatment begins too late, permanent damage is to be expected.

Diagnosis and course

Funicular myelosis is diagnosed on the basis of characteristic symptoms such as pale yellow discoloration of the skin and sclerae, Hunter glossitis, sensory disturbances and impaired intrinsic reflexes (legs, feet), gait unsteadiness, positive Romberg sign, pathologic reflexes (including Babinski’s reflex, Gordon’s reflex, Bechterew-Mendelian reflex), impaired vibratory sensation, impaired positional sensation, signs of dementia, and depressed mood and even delusions. In addition, in most cases (over 65 percent) the protein concentration in the cerebrospinal fluid (CSF) is slightly elevated, while the nerve conduction velocity (in 75 percent) is slowed.A blood test can reveal enlarged erythrocytes and hypersegmented granulocytes as well as a reduced vitamin B12 concentration. Furthermore, homocysteine and methylmalonate levels in the urine are usually elevated. The Schilling test can be used to differentiate whether the vitamin B12 deficiency is due to inadequate intake or malabsorption. The course and prognosis of funicular myelosis depend largely on the time of diagnosis and the start of therapy. Early initiation of therapy ensures regression of symptoms and a good prognosis, whereas in advanced funicular myelosis many symptoms are irreversible.

Complications

In most cases, only adults suffer from myelosis. In these cases, there is an increase in the patient’s experiencing sensory dysfunction and sensory disturbances in the hands and feet. Sensory disturbances also occur due to this disease. Due to these disturbances, the patient’s quality of life is considerably reduced and everyday life becomes more difficult. In most cases, the performance of various activities is no longer possible without further ado. On the body, paralysis occurs in various regions, which can also lead to movement restrictions. Coordination disorders can also make everyday life more difficult and lead to psychological complaints. It is not uncommon for patients to complain of depression or other psychological upsets. Myelosis must be treated at all costs. Without treatment, the further course of the disease usually leads to complete paraplegia. This has a very negative effect on the quality of life of the affected person. In most cases, myelosis can be limited and treated relatively well with the help of medication. No particular complications occur. In most cases, the paralysis and movement restrictions then also disappear again and there is no reduced life expectancy.

When should you see a doctor?

If the affected person suffers from movement disorders, gait unsteadiness or dizziness, he should consult a doctor. If he loses his balance and needs assistance in moving around to reduce the general risk of accidents, a doctor should be consulted. If there are signs of paralysis on the body, repeated weakness, lassitude, and fatigue, there is cause for concern. If changes in vision are noticed due to decreased vision or increased sensitivity to light, these observations should be discussed with a physician. Decreased libido and, in men, reduced potency are considered unusual and should be medically clarified. If there are abnormalities in the appearance of the skin, sensory disturbances or problems with the perception of sensitivity on the skin, it is advisable to consult a doctor. If psychological as well as emotional disorders arise, a doctor is also needed. In case of persistent depressive mood, melancholic experience, apathy or decreased drive, a doctor or therapist should be consulted. If the affected person notices an impaired reflex reaction and shows dementia-like symptoms, a visit to the doctor should be made. Comprehensive medical examinations are necessary to clarify the cause. If relatives notice that the affected person shows signs of delusion, a doctor should be consulted. Action is needed to prevent further deterioration of the health condition.

Treatment and therapy

Therapeutic measures in funicular myelosis are aimed primarily at reducing the symptoms of deficiency by parenteral substitution of vitamin B12. For this purpose, vitamin B12 is substituted in the course of intravenous or intramuscular injections or infusions. At the beginning of the therapy, a daily injection of vitamin B12 (e.g. 1mg/d i.m. hydroxycobalamin in the first two weeks) is required. Due to the good storage capacity of the liver with regard to vitamin B12, the injections or infusions can be successively reduced to weekly, then to monthly and finally to quarterly applications in the further course. Substitution therapy can halt progression of the disease and worsening of symptoms. If only the myelin sheaths are involved, the symptoms are usually reversible. If the axon cylinders are also damaged, residual symptoms remain in most cases.In some cases (especially in mild funicular myelosis), the symptoms may worsen at the beginning, so that good compliance (adherence to therapy) on the part of the affected person is required. If there is also marked anemia, potassium and iron should be substituted to prevent relative deficiency. In some cases, supplemental or monotherapeutic folic acid substitution may be indicated to correct hematologic disorders resulting from funicular myelosis.

Prevention

Funicular myelosis can be prevented by avoiding vitamin B12 deficiency. In addition to consistent therapy of possible underlying diseases, a varied diet (meat, fish, dairy products) should be observed for this purpose. Regular control examinations in chronic inflammatory diseases of the intestinal tract allow an increased vitamin B12 requirement to be detected at an early stage and accordingly prevent funicular myelosis.

Follow-up

In this disease, the options for follow-up are very limited. In most cases, the disease can also not be treated completely, so that the patient is thereby dependent on lifelong therapy to permanently alleviate the symptoms. The main focus is on early detection and treatment of this disease in order to avoid complications. As a rule, those affected are dependent on taking medication to reduce the vitamin B12 deficiency. Care must be taken to ensure correct and, above all, regular intake. In the case of children, parents must pay attention to the correct intake and possible interactions with other medications. Furthermore, regular examinations of the internal organs are also very useful in order to detect damage to the liver or kidneys at an early stage. In many cases, those affected are also dependent on taking iron or potassium, as there is also a deficiency in the body of these elements. A balanced and healthy diet can also alleviate these symptoms. Frequently, contact with other patients is also useful, as this can lead to an exchange of information that can make everyday life easier. Life expectancy usually remains unchanged.

What you can do yourself

Funicular myelosis is easily treated, especially in the early stages. It usually arises from a deficiency of vitamin B12. Therapy is based on a precisely dosed supply of the missing vitamin B12, which the physician makes in consultation with the patient. Self-therapy and uncontrolled intake of vitamin B12 are not recommended. Patients should urgently follow their doctor’s instructions and discuss the further course of therapy with him on an ongoing basis. This also includes regular check-ups. If patients cooperate closely with their physician, there is a good chance that funicular myelosis, if it is still in its early stages, will be completely cured. Once the disease has been cured, further administration of vitamin B12 at long intervals can have a preventive effect. If the disease is already more advanced when it is diagnosed, it can also still be treated well. In most cases, further progression can be prevented and the symptoms alleviated. It is also very important not to undertake self-therapies, but always to consult with the treating physician. A healthy and balanced lifestyle with a varied diet, exercise in the fresh air and consistent avoidance of addictive substances strengthens the body’s immune defenses. In this way, the patient can do much to improve his or her health.