In progressive bulbar paralysis, the motor cranial nerve nuclei of the trigeminal, facial, glossopharyngeal, vagus, and hypoglossal nerves die. This atrophy results in paralysis of the face and esophagus. Similar symptomatology characterizes ALS, so progressive bulbar paralysis is sometimes referred to as an ALS subtype.
What is progressive bulbar paralysis?
Progressive bulbar palsy is a systemic progressive atrophy associated with tissue loss in the motor cranial nerve nuclei. The tissue atrophy has the medulla oblongata as its center and spreads from there. In addition to a form of the disease in adults, an infantile variant with infantile age of manifestation exists. Both forms of the disease belong to the neurological diseases and affect mainly the motor neurons. Progressive bulbar paralysis is classified as a spinal muscular atrophy associated with a specific distribution pattern. With disease onset in childhood, the disease is sometimes called Fazio-Londe syndrome. Adult-onset progressive bulbar paralysis is referred to by some sources as a special form of the degenerative disease ALS. When progressive bulbar paralysis is associated with symptoms of deafness, it is also called Brown-Vialetto-van Laere syndrome.
Causes
The exact causes of each form of progressive bulbar paralysis are as yet unknown. In some cases, scientists have been able to detect a mutation of a substance called Cu-Zn superoxide dismutase. This substance is an enzyme that carries out transformation processes in the body and catalyzes reactions with the product hydrogen peroxide. The relationship with the degenerative disease ALS is suspected mainly due to the discovered mutation in the SOD gene, which codes for the described enzyme. Thus, this mutation can be detected not only in many cases of progressive bulbar paralysis. According to recent research results, the defects in the SOD gene can also be detected in people with the hereditary familial form of ALS. The defect results in cytotoxic effects of unstabilized SOD. The mutation supports a high accumulation tendency of the corresponding protein, which is responsible for cell death. Only nuclear lesions of the cranial nerve nuclei cause bulbar paralysis. In contrast, a supranuclear lesion causes pseudobulbar paralysis.
Symptoms, complaints, and signs
Progressive bulbar paralysis causes the tissues of the motor nuclei to gradually perish. Patients suffer from increasing difficulty with everyday and vital movements such as chewing, swallowing, or speaking. The gag reflex of most affected persons is significantly reduced within a very short time. Only weak movements in the facial area are still possible for them. Unlike ALS, the entirety of the motor core area is not affected by the degenerative changes. Instead, the disease focuses primarily on cranial nerves V, VII, IX, X, and XII, as well as the corticobulbar tracts of innervated muscles. Thus, the disease predominantly affects the motor neurons in the core areas of the trigeminal, facial, glossopharyngeal, vagus, and hypoglossal nerves. Therefore, unlike patients with ALS, patients do not usually suffer from spastic or flaccid paralysis of the limbs. The lungs and heart are also not affected. Progressive bulbar paralysis symptomatically focuses on the face, preserving the eye muscle nuclei.
Diagnosis and course of the disease
The diagnosis of progressive bulbar paralysis is made using imaging techniques. MRI or CT shows nuclear lesions in the appropriate nuclear areas. The disease must be differentially diagnosed from ALS. Because of the progressively increasing dysphagia, all forms of the disease have an unfavorable prognosis. A common complication is aspiration of food particles or saliva, which often causes pneumonia and frequently leads to patient death within one or three years. In most cases, the disease progresses at a rapid rate. Rapid progression worsens the prognosis.
Complications
Progressive bulbar paralysis has a very poor prognosis. Purely symptomatic treatment is used to try to reduce the risk of complications occurring.The main symptom of progressive bulbar paralysis is increasing dysphagia. Due to the obstruction of the swallowing process, the patient can no longer take in food and would starve to death without artificial nutrition. In addition, however, there is always a risk of aspiration of food, which can lead to fatal complications. Aspiration is the unintentional inhalation of food, fluids or foreign bodies, which then enter the bronchial tubes. There, they can lead to severe infections because the body alone is unable to remove the foreign bodies from the bronchial tubes. Severe pneumonias (lung infections) often develop as a result of these aspirations of food or saliva. In infantile progressive bulbar paralysis, these complications often lead to death between the first and third years of life. In adulthood, progressive bulbar paralysis often occurs in the context of amyotrophic lateral sclerosis (ALS). Here, the paralysis of the swallowing muscles already represents a particular complication of ALS and is responsible for the poor prognosis of this disease. Progressive bulbar paralysis with deafness (Brown-Vialetto-van Laere syndrome) has the best prognosis. In addition to rapidly progressive disease courses leading to death, the course can be arrested at least temporarily in one third of patients.
When should you see a doctor?
Restrictions in swallowing, problems with chewing, and visual abnormalities in the face as well as neck area should be presented to a physician. If food intake is refused, weight loss occurs, or the organism is undersupplied, the affected person needs medical help. Disturbances of the gag reflex or irregularities in respiratory activity should be examined and treated. If a slow increase in symptoms becomes apparent over several weeks or months, a physician must be consulted. In severe cases, food can no longer be ingested due to the impairments. This results in a life-threatening condition for the affected person. In order to enable a diagnosis to be made at an early stage, a visit to the doctor should be made at the first signs. If the affected person chokes repeatedly or develops a fear of choking, a doctor should be consulted. Hyperventilation, a loss of muscle strength, and signs of paralysis should be presented to a physician as soon as possible. If the person’s speech changes, if he or she shows withdrawal behavior or if his or her performance decreases, the person needs help. Slurred speech or a refusal to speak in children should be regarded as warning signs. If there is no change despite an understanding environment, a doctor is needed. If there is a deficiency, internal dryness, or problems cleaning teeth, a doctor should be consulted.
Treatment and therapy
Causal therapy is as yet unavailable for patients with progressive bulbar paralysis as it is for patients with ALS. For this reason, treatment is purely symptomatic, consisting primarily of aspiration prophylaxis and saliva reduction. Nutrition is provided by feeding tubes to exclude aspiration of food components. Most patients suffer from hypersalivation. As the symptoms progress, they are no longer able to swallow the saliva and choke. Conservative therapy of this symptomatology consists in the administration of anticholinergic drugs, such as amitriptyline or methionine. Alternatively, Botox may be injected to paralyze the salivary glands. Since many patients suffer from anxiety, the administration of fast-acting benzodiazepines may also be considered as part of the therapy. In most cases, these drugs are administered as drops because patients are unable to swallow. One of the most important components of treatment is psychological support for patients and their relatives. Since those affected by the adult form in particular have to experience the progression of the disease while fully conscious, psychotherapy is intended to enable patients to process and cope better with the disease. Since 1996, the glutamate antagonist riluzole has been approved for delaying ALS. Whether this drug can also delay the progression of progressive bulbar paralysis has not been clarified. ALS is now also treated in the USA using stem cell therapy. This therapy is not approved in Germany.In addition, the efficacy of therapy in progressive bulbar paralysis is not considered confirmed.
Prevention
Progressive bulbar paralysis cannot be prevented at this time because the causes of the disease have not yet been conclusively determined.
Follow-up
Progressive bulbar paralysis is a currently incurable disease, so follow-up care is very limited. The primary concern here is to reduce symptoms with the help of symptomatic follow-up. Since the risk of progressive dysphagia (swallowing disorder) is high in this disease, it is important to monitor it. There is also a high risk of inhalation of food and possible choking or inflammation of the airways. In this case, the patient is fed prophylactically, usually via tubes. Furthermore, hypersalivation, an increased saliva production, is attempted to be reduced. This is usually done by administering drugs such as amitriptyline or methionine. Botox injections into the salivary glands are also another alternative. Psychological care is also important, as affected individuals often suffer from depression or anxiety. In some cases, additional medication is also necessary. After the disease with progressive bulbar paralysis, regular examinations are advisable to monitor the progression of the disease and adjust medications if necessary. Progressive bulbar paralysis has a poor prognosis. The rapid progression of the disease to death can be delayed in only one-third of patients. Several therapeutic approaches, such as stem cell therapy, are already available, but they are still in the testing phase.
Here’s what you can do yourself
The options for self-help are very limited in progressive bulbar paralysis. The disease has an unfavorable prognosis and a difficult course. In daily life, it is important for the patient to work closely with the medical and nursing team. Immediately after diagnosis, the patient should obtain comprehensive information about the disease and its further development. The restructuring of everyday life and the organization of adequate care are vital. They should be done in time to avoid additional complications. In order to be able to handle the adversities of the disease well, it is necessary that mental strengthening takes place. In addition to the use of various relaxation methods as well as mental techniques, psychotherapeutic support is advisable. The joy of life and the well-being are to be promoted. The handling of the illness must be learned. In addition, mental illnesses must be prevented. The exchange with other affected persons can be helpful and beneficial. Self-help groups or closed Internet forums provide an opportunity for communication with other sufferers. The mutual help for self-help is lived there. Since progressive bulbar paralysis is a heavy burden for relatives, they should also be informed comprehensively about further developments in good time. Cohesion within a family is important for maintaining the patient’s health and should be cultivated.
