- What is myasthenia Gravis in children
- What triggers / Causes of myasthenia Gravis in children
- Pathogenesis (what is happening) at the time of myasthenia Gravis in children
- The symptoms of myasthenia Gravis in children
- Diagnosis of myasthenia Gravis in children
- Treatment of myasthenia Gravis in children
- Prevention of myasthenia Gravis in children
- Which doctors should be consulted if You have Myasthenia in children
What is myasthenia Gravis in children
Myasthenia gravis is an autoimmune disease, transient muscle weakness and abnormal fatigue. Immunological disorders in infants have genetic conditioning.
The prevalence of myasthenia gravis is 1-5 cases per 100 thousand population, there is a tendency to increase the number of patients. Children and adolescents up to 17 years old accounted for 9-15 patients with myasthenia gravis often affects girls. The average age-of-onset – 7.2 years. Clinical observations show that infants can begin at any age.
What triggers / Causes of myasthenia Gravis in children:
The basis of the origin of myasthenia gravis is an autoimmune response to the acetylcholine receptor (AHR) in skeletal muscle. Antibodies to acetylcholine receptors are the cause neuromuscular block.
Manifestation of immunopathological reactions in patients with myasthenia consider changes in thymus or thymus, the Central organ of the immune system). It is observed in most patients in whom the disease developed at the age from 1 year to 17 years. Immunological methods allow to determine in patients with myasthenia change the structures of the postsynaptic membrane.
Pathogenesis (what is happening) at the time of myasthenia Gravis in children:
In children born to mothers with myasthenia, in 10-20 of cases are diagnosed in the neonatal myasthenia, which myasthenic syndrome is transient in nature. Clinical symptoms include General muscle hypotonia, weak cry, difficulty breathing and sucking, may develop ptosis (drooping of an organ), amimia, oculomotor disorders, swallowing disorders, decreased deep reflexes. It is proved that a transient myasthenic syndrome, which is manifested in these children in the first days of life and continuing for 1-1,5 months., due to the postponement of the placental barrier antibodies to the mother-Ahram.
There are 6 forms of congenital myasthenia with different types of inheritance, which should be considered as congenital myasthenic syndromes. Among them are:
- an autosomal recessive syndrome with generalized muscle fatigue, caused by a deficiency of acetylcholinesterase endplates-
- an autosomal dominant syndrome with weakness and atrophy of the shoulder muscles and forearm muscles-
- an autosomal recessive syndrome in which the size of synaptic vesicles containing akhr below normal-
- an autosomal recessive syndrome caused by a decrease in the number of Ahram on endplate-
- an autosomal recessive syndrome, manifested generalized abnormal fatigue of the muscles, due to reduced content of synaptic vesicles and reduced release of acetylcholine-
- an autosomal dominant syndrome with bulbar weakness and lumbar muscles, increasing muscle tension and contact with the heat.
It should be emphasized that congenital myasthenic syndromes usually occur in children whose mothers do not suffer from myasthenia gravis, myasthenic symptoms are determined at birth.
Identify the following types of disorders of myasthenia gravis:
- generalized two types:
- without respiratory failure and cardiac activity-
- problems with breathing and cardiac activity.
- pharyngeal-front: without breathing problems - breathing problems-
- without breathing problems-
- problems with breathing.
The symptoms of myasthenia Gravis in children:
In childhood is more common juvenile form of myasthenia gravis. The first symptoms can be oculomotor disorders: ptosis, limitation of movements of the eyeballs, double vision. The last symptom is sometimes difficult to identify, as small children often can't explain their feelings. Marked disturbances of masticatory muscles, facial muscles, disorders of swallowing, dysphonia, dysarthria. Often appears abnormal fatigue in the muscles of the pelvic girdle, neck, upper extremities. The face of a sick child can have a lifeless expression, often upper eyelids drooping, eyes fixed. There is a growing ptosis, indistinctness of speech, the appearance of a nasal tone of voice – at the end of a long conversation - there is a fatigue with repeated active movements. Muscle weakness and fatigue usually increase toward the evening.
The progression of muscle weakness is noted after physical effort. So, there is ptosis with repeated squatting, hand grip into a fist, with repeated horizontal movements of the eyeballs.
In children myasthenia gravis often begins monocentre, but very quickly joined by other symptoms - typical generalization process during the first months. The course is usually progressive, most of the children identified generalized forms with severe manifestations. Local forms of myasthenia gravis in children occur in 12 cases for their more severe than in adults.
When the pharyngeal-facial and skeletal-muscular form rapidly developed respiratory failure and cardiac activity.
In a generalized form of myasthenia gravis in the pathological process involved primarily the muscles of the cranial division, neck, limbs, torso. Fatigue and muscle weakness worse after exercise, by the end of the day. Movement disorders are caused by a primary lesion of the muscles of the departments of the arms, legs, weakness of the neck muscles.
With eye form the clinical picture is dominated by oculomotor disorders: ptosis, unilateral or bilateral, double vision, strabismus the degree of symptoms is unstable, amplifying the evening, decreasing after the holiday, celebrated a kind of "nystagmus" due to the weakness and fatigue extraocular muscles.
When the pharyngeal-facial form of myasthenia gravis weakness of facial muscles combined with weakness of the muscles of the larynx, soft palate and tongue, you may experience the stillness of the tongue, palate. This is manifested by impaired speech (phonation and articulation), swallowing.
Diagnosis of myasthenia Gravis in children:
Diagnosis of myasthenia gravis in children represent a considerable challenge in connection with the variability of clinical symptoms and peculiarities of examination of the child.
Objective clinical examination is to identify the main symptom of the disease – abnormal muscle fatigue. To confirm the diagnosis used proteinemia test, electromyography, scintigraphy of the thymus gland, the immune status.
Proteinemia sample with the assessment of force and fatigue of the affected muscles is done before and after 30 min after intramuscular injection of 0.05 solution of neostigmine in a single age dose. Distinguish:
- dramatically positive preteenboy trial, when no myasthenic symptoms-
- positive test – only symptoms
- weakly positive samples, thereby reducing the severity of myasthenic symptoms-
- questionable preteenboy sample – the severity of the manifestations of myasthenia gravis varies slightly-
- negative preteenboy sample – clinical symptoms is not changed after the administration of neostigmine.
About the diagnosis of myasthenia gravis can be judged as being one of the first three options preteenboy samples.
Electrophysiological studies in infants are held for the purpose of definition of the phenomenon "myasthenic reaction" progressive deterioration of strength of muscle contractions during nerve stimulation. Currently the children use the global electromyography, in which after exercise showed a significant decrease in the amplitude, the time reduction of electroactivity, the reduction in the frequency of action currents. To clarify the nature of the pathology of the thymus exploring not only the functional activity of the thymus, but also spend tomography of the anterior mediastinum, PrimaMedia-stenography, computed tomography of the chest. It is known that 8-9 patients with myasthenia diagnose a tumor of the thymus – thymoma characterized by a rapid development, mainly affecting the muscles engaged in the act of swallowing, facial muscles.
Along with the assessment of immune status, make a serological assay for determination of antibody to AHR, the number of which in most patients is increased. In localized forms of myasthenia gravis these indicators and electrophysiological data may not be changed, therefore, the differential diagnosis of localized forms of myasthenia gravis complicated enough. Differential diagnosis is needed to rule out diseases in the structure of the myasthenic syndrome. These include botulism, poisoning by antibiotics of the aminoglycoside, illness Itsenko-Cushing's, Addison's disease, Hypo - and hyperthyroidism, polymyositis.
Treatment of myasthenia Gravis in children:
In the treatment of myasthenia gravis use of conservative and surgical methods.
The basis of conservative treatment consists of anticholinesterase drugs (AHAP). Use neostigmine (neostigmine), kalimin (pyridostigmine bromide), oksazil. Dose AHAP individually and depends on the age of the child, the form of the disease, results preteenboy samples, allowing to assess the reaction to the drug, attained the degree of compensation, the presence or absence of side effects. When choosing AHAP considered inherent pharmacokinetics:
Neostigmine when administered subcutaneously at a dose of 1-2 ml of 0.05 solution works in 15-20 minutes, the maximum effect manifests itself after 30-40 min after injection. The duration of action is 2-3 hours
Kalimin ingestion causes the effect using 40-90 min, which lasts up to 5-6 hours
Oksazil starts to act in 45-50 min for 6-8 hours
With difficulty swallowing, often using a combination of AHAB: 30 minutes before food administered intramuscularly 1 ml of a solution of neostigmine 0.05 and 1 hour after it appointed interior kalimin giving a more lasting effect.
In cases of severe overdose, AHAP can develop cholinergic crisis, which is manifested by symptoms of combined muscarinic and nicotinic intoxication. Arise bradycardia, miosis, fibrillary twitching, increased salivation, colicky abdominal pain, vomiting, diarrhea, agitation, breathing problems (bronchospasm, hypercapnia). In severe cases, develops tremors, convulsions and death. At a younger age (under 1 year) the body more resilient to anticholinesterase drugs. Therefore, parents need to be very careful to make sure proyavleniem side effects in children. In case of cholinergic crisis requires immediate hospitalization of the sick child. Cholinergic crisis develops slowly, over several days, it is characterized by tingling in the muscles, a feeling of spasm in the throat, signs of peripheral vascular insufficiency: pale skin, cold extremities, mottled skin.
Also patients may experience a myasthenic crisis, in which the weighting of the patient's condition is due to an insufficient dose of AHAP. In the treatment of myasthenic crisis use neostigmine or kalimin in higher doses.
Some drugs aggravate the course of myasthenia gravis: antibiotics (neomycin, streptomycin, te-tracycline), d-penicillamine, hydantoin, magnesium-containing drugs, quinine, quinidine, clonazepam, and muscle relaxants, polymyxin b, kanamycin, gentamicin, lincomycin, clindamycin, phenytoin, lithium carbonate, tricyclic antidepressants, novopassit.
In severe myasthenia prescribe corticosteroids: prednisolone 1.5 mg/kg per day or more, depending on clinical condition of the patient.
Noteworthy method of enterosorption, in particular with the use of Politeama. This method leads to improved neuromuscular transmission. There is evidence of successful use in children with myasthenia gravis and plasmapheresis as a component of complex therapy.
Myasthenia gravis can be used immunoglobulin for intravenous administration (Intraglobin, immunoglobulin (Pentaglobin). They are administered in a dose of 400-1000 mg/kg / day for 2-5 days. Individual intolerance to immunoglobulins can be manifested by headache, nausea, dizziness, vomiting, diarrhea, tachycardia, cyanosis, dyspnea, pyrexia, chills, increased sweating, back pain, myalgia, etc. these symptoms may occur within 30 min after the start of infusion and observed in the first days.
Surgical treatment of myasthenia gravis in childhood is thymectomy (removal of thymus), which in infants is positive in 70-80 cases. The main indications for thymectomy:
- the presence of thymoma or cysts of the thymus
- insufficient efficiency of treatment using AHAP-
- resistance to the therapy, despite the high-dose AHAP-
- intolerance AHAP.
In children, surgical treatment is indicated in severe and moderate forms of the disease. The best results are observed in patients with minimal disease duration. Children who were sick with infants less than 5 years, have improved after surgery in 98 cases, more than 5 years – only in 71.
After surgery thymectomy patients transferred to the hospital. The treatment continues with a reduced dose of the drugs AHAP further prescribe b vitamins, vitamin E, ATP. Long-term monitoring of children with myasthenia gravis undergoing surgery thymectomy, shows that the excellent and good results (a full recovery, a significant improvement) were observed in 75-80 patients.
Corticosteroids (prednisone, etc.) designate:
- in the preoperative period – with a severe form of myasthenia gravis-
- in the postoperative period, with no effect of thymectomy or when the deterioration in the near or long-term period. There are various schemes of corticosteroid therapy, which are developed and assigned individually depending on the severity of the disease.
Currently, despite advances in therapy, the improvement of methods of treatment of myasthenia gravis in children.
Prevention of myasthenia Gravis in children:
If child is diagnosed with myasthenia, he is banned for excessive exercise and long exposure to the sun. The child's diet should contain low-calorie products. In order to prevent the need to take medications that strengthen the immune system. During treatment and prophylaxis in infants there are a number of drugs that are not indicated for use, these include: antipsychotics, diuretics, tranquilizers, antibiotics groups of ftorkhinolonov. Therefore, the choice of drug should be cautious.