Alternans syndromes are brainstem syndromes that cause crossed paralysis symptoms and are usually due to strokes in the brainstem region. Conceivable causes are also tumors or inflammatory processes in these regions. Treatment is dependent on the primary cause, but includes physical therapy and speech therapy in virtually all cases.
What is alternans syndrome?
Alternans syndrome, as it is called, is a brainstem syndrome that results from unilateral decreased blood flow to the brainstem. With the exception of the cerebellum, the brainstem is defined as all parts of the brain below the diencephalon. The midbrain with cerebral peduncle, midbrain dome and midbrain roof thus makes up the anatomical unit of the brainstem together with the rhomboid brain including the bridge and myelencephalon. The brainstem controls vital body processes such as respiration, blood pressure, and cardiac activity. In addition, vital reflexes such as the vomiting and coughing reflexes are located in this part of the brain. When there is damage to areas of the brainstem, so-called brainstem syndromes occur. Brain stem syndromes are always related to reduced blood flow to the brain stem and can show different symptoms. The so-called Alternans syndrome is a brainstem syndrome that is due to a one-sided reduced blood supply to the brainstem. Characteristic are failures of cranial nerves on the affected side of the brain. In addition, hemiparesis with hemifacial sensory loss occurs on the opposite side of the body. Depending on the exact localization of damage, Alternans syndrome corresponds to Jackson syndrome, Weber syndrome, Millard-Gubler syndrome, or Wallenberg syndrome.
Causes
The cause of each brainstem syndrome is cerebral ischemia. In most cases, each syndrome is caused by circulatory disturbances in the basilar or vertebral arteries. In individual cases, tumors, inflammatory diseases such as multiple sclerosis, mechanical injuries, or infections may also trigger the insufficiency. Alternans syndromes are usually preceded by vascular damage caused by strokes. Depending on the exact localization, Alternans syndrome is further subdivided. Millard-Gubler syndrome is mentioned in case of circulatory disturbance in the pons area. Weber syndrome is caused by circulatory disturbance in the midbrain and Wallenberg syndrome is due to circulatory damage in the region of spinal cord extension. In circulatory disorders and ischemic processes, the tissues no longer reach sufficient amounts of blood. Since the blood carries vital oxygen, nutrients as well as messenger substances, individual cells die due to the reduced supply. The crossed symptoms of Alternans syndromes are due to the fact that cranial nerves descend to their supply areas on the same side. Spinal cord fibers, on the other hand, each descend to the opposite side of the body.
Symptoms, complaints, and signs
Patients with Alternans syndrome suffer different symptoms depending on the location of damage. Weber syndrome causes oculomotor nerve palsy on the same side of the brain damage to the side, which is like a kind of unilateral gaze paralysis. On the opposite side of the body, spastic hemiplegia occurs due to increases in muscle tone, which may also affect the mimic muscles due to damage to the tractus corticonuclearis. In Millard-Gubler syndrome, abducens paresis with peripheral facial paresis again occurs toward the side of the damage. On the opposite side of the body, as in Weber syndrome, there is spastic hemiplegia. In contrast, Wallenberg’s syndrome leads to Horner’s syndrome and additionally evokes hemiparesis, soft palate paralysis, dysphonic hoarseness, and inability to speak. There is excessive sensitivity in the facial region. In addition, rotational vertigo may occur. On the opposite side of the damage, dissociated sensory disturbances occur due to damage to the tractus spinothalamicus lateralis. Jackson syndrome is distinguished from the other alternans syndromes primarily by paralysis of the tongue.
Diagnosis and course
The suspected diagnosis of Alternans syndrome is made by the physician on the basis of visual diagnosis. In this context, the crossed paralysis symptoms are particularly diagnostic. The neurologist obtains confirmation by imaging of the brain.By means of this imaging, the primary cause of the syndrome can also be localized. If tumors in the brainstem are responsible for the symptoms instead of circulatory disturbances, these changes show a relatively typical image on MRI. The prognosis for patients with Alternans syndrome depends on the extent of damage, the localization, and the primary cause of damage.
Complications
A hallmark of Alternans syndrome is reduced blood flow to the brainstem, resulting in nerve loss on the affected side of the brain. Complete paralysis and hemiplegia occur on the opposite side of the body. Depending on the exact location of brain damage, alternans syndromes are classified as Weber syndrome, Wallenberg syndrome, Millard-Gruber syndrome, and Jackson syndrome. Circulatory disturbances in the midbrain or blood flow-related previous diseases in the area of the spinal cord extensions indicate Wallenberg syndrome. As a result of these disorders, individual cells of the body die because they are no longer supplied with sufficient oxygen and messenger and nutrient substances. Depending on the location of the damage, spastic hemiplegia may occur, as in Weber syndrome, resulting in reduced facial expression. Paralysis of the sixth cranial nerve causing double vision and facial paralysis indicates Millard-Gruber syndrome. Movement disorders, hoarseness, speech disorders, rotational vertigo, and increased sensitivity in the facial area are signs of Horner syndrome, a specific nerve damage to the eye muscles. Jackson syndrome is characterized by paralysis of the tongue. The crossed paralysis symptomatology leaves permanent damage in most cases because the nerve tissue of each part of the brain is highly specialized. Therefore, the prospect of recovery or at least partial regeneration is very low even with timely diagnosis and appropriate treatment. If Alternans syndrome is due to a tumor in the brainstem or to a stroke, an improved quality of life sets in with consistent postoperative therapy.
When should you see a doctor?
In alternans syndrome, medical examination and treatment are necessary in any case. The complaints do not disappear on their own and there is no spontaneous healing or improvement of this syndrome. However, not all complaints can be narrowed down. As a rule, the treatment also depends on the cause of the alternans syndrome. In any case, a doctor should be consulted if Alternans syndrome causes movement restrictions and an inability to speak. The movement restrictions can also be associated with paralysis over the entire body. Sensory disturbances can also occur in the face, which also indicate the syndrome. Furthermore, most patients also suffer from dizziness and nausea. A doctor should also be consulted if there are sudden visual complaints, as these may indicate complaints in the brain. Likewise, treatment must take place if a stroke occurred prior to Alternans syndrome or if the affected person suffers from heart problems. In this case, however, not all complaints can be completely alleviated, so paralysis may remain.
Treatment and therapy
Damage to the brain often leaves permanent damage. The nerve tissue within the brain portions is highly specialized. Unlike other body tissues, the ability to regenerate is therefore severely limited. After damage, cells can migrate into other tissues of the body and take over the specific functions of the respective tissue type. In the brain, this is only possible to a limited extent because the specializations here are too great. However, it has been observed, especially in stroke patients, that consistent exercise and specific training can induce neighboring brain tissue to take over the function of the defective area. Therefore, depending on the damaged areas, physiotherapy and speech therapy sessions take place, which can promote a redistribution of brain functions. To prevent strokes in the future, patients receive supportive therapy. This treatment consists of minimizing risk factors and possibly drug therapy that thins the blood. If it is not a stroke but a tumor that has caused the Alternans syndrome, surgical treatment takes place.Depending on the degree of malignancy and the operability of the tumor, drug therapy may be considered as an alternative or at the same time. Acute inflammations are in turn brought to an end with drugs such as cortisone or antibiotics. In the case of autoimmunologic inflammation due to multiple sclerosis, patients also receive long-term immunosuppressive therapy.
Outlook and prognosis
Alternans syndrome causes many different neurologic and mental symptoms. The affected person’s quality of life is significantly reduced by the syndrome, so that he or she may be dependent on the help of other people in everyday life. There are also disturbances in movement and coordination. Furthermore, an inability to speak can occur and the affected person sometimes suffers from sensory disturbances or even paralysis. Furthermore, there are often feelings of dizziness or spinning vertigo. Paralysis of the tongue can also occur, so that patients are no longer able to take in food or liquids properly. This can lead to deficiency symptoms or dehydration. The patient’s relatives or parents may also experience severe psychological distress as a result of the symptoms. Alternans syndrome can be treated by various therapies. However, it cannot be generally predicted whether this will result in a positive course of the disease. It is possible that the affected person will have to live with these limitations for the rest of his or her life. Life expectancy is usually reduced only if the tumor cannot be removed.
Prevention
Because alternans syndromes are usually caused by strokes, the same prevention steps that apply to strokes apply to the prevention of symptomatology. For example, smoking should be refrained from. In addition, a change in diet can be considered. Sufficient exercise also represents a step in stroke prevention. Regular monitoring of blood pressure levels can also be helpful.
Follow-up care
In alternans syndrome, there are very limited aftercare measures available to affected individuals. As a rule, medical treatment is always necessary to relieve the symptoms and prevent the death of the affected person. Self-cure does not occur, and the symptoms cannot be treated by self-help measures. The treatment is usually carried out with the help of medication or antibiotics. The patient should always ensure that the medication is taken regularly and should also take into account possible interactions with other medications. In the case of antibiotics, it is important to ensure that no alcohol is consumed when taking them, so as not to weaken the effect of the antibiotics. Furthermore, physiotherapy measures are often necessary. In this case, many of the exercises can also be repeated and performed in the patient’s own home, thus accelerating the healing of the affected person. In the case of a tumor in Alternans syndrome, it is usually removed by surgery. After such an operation, the patient should always rest and take care of his body as much as possible. Strenuous activities or other stressful activities should be refrained from. Contact with other patients of Alternans syndrome can also be useful to exchange information about therapeutic methods.
Here’s what you can do yourself
Alternans syndrome must always be diagnosed and treated by a doctor. The measures that affected individuals can take themselves depend on the severity of the syndrome. A mild Alternans syndrome can at least be alleviated by physical and occupational therapy. Physical exercise counteracts the physical symptoms of failure, as do regular sports, yoga or Pilates. In addition, dietary measures such as a balanced diet and the avoidance of stimulants also help. Severe alternans syndrome cannot be treated independently. The affected person usually only has to accept the neurological and mental symptoms. Once the disease has been accepted, the quality of life can gradually be improved again by forming new hobbies and a healthy lifestyle. The relatives of those affected must also learn to accept the new living conditions, whether through therapeutic measures or a change in previous lifestyle habits.Through acceptance and the exhaustion of medical possibilities, a certain normality in daily life can be restored despite the disease. The doctor in charge can give valuable tips on how to deal with Alternans syndrome and guide the way back to life.
