[Ocular myasthenia gravis]. / Miasteniya, glaznaya forma.

The article describes an urgent medical and social problem - the diagnosis and treatment of the ocular myasthenia gravis. Despite recent advances in the study of synaptic pathology, the diagnosis of the ocular form of myasthenia gravis remains a challenging problem. This is due to the poor information content of laboratory and electromyographic methods in the diagnosis of ocular myasthenia gravis, and the generalized myasthenia gravis manifests in 90% of cases by external ophthalmoplegia and ptosis. The article highlights the features of the diagnosis and differential diagnosis of ocular myasthenia gravis. Data on the course and features of the clinical presentation of the disease are presented. The importance of analyzing anamnestic data and clinical manifestations of the disease is emphasized. The article discusses modern approaches to the treatment of the ocular myasthenia gravis. The authors present clinical observations of 2 patients with ocular myasthenia gravis.

[Seronegative nonparaneoplastic Lambert-Eaton myasthenic syndrome]. / Seronegativnyi neparaneoplasticheskii miastenicheskii sindrom Lamberta-Itona.

The authors studied two patients with Lambert-Eaton myasthenic syndrome (LEMS) in whom the repeated examination did not find specific of LEMS P/Q type voltage-gates calcium channel autoantibodies. The results of clinical testing and electrophysiological examination showed the typical character of movement disorders with the absence of tendon reflexes and signs of disautonomia as well as a decrease in M-response amplitude and phenomena of decrement with low frequency- and increment with high frequency stimulation. Both patients revealed no signs of paraneoplastic process. Autoimmune character of the damage was confirmed by the effectiveness of treatment with glucocorticoid hormones.

[A comparative analysis of the informative value of anti-AChR-antibody radioimmunoassay and laser correlation spectroscopy in myasthenia gravis]. / Sravnitel'nyi analiz informativnosti radioimmunologicheskogo opredeleniya antitel k atsetilkholinovomu retseptoru i lazernoi korrelyatsionnoi spektroskopii pri miastenii.

AIM: An aim of the study was to compare informative value of traditional approach (anti-AChR antibody radioimmunoassay) and evaluation of metabolic shifts by laser correlation spectroscopy in myasthenia gravis. MATERIAL AND METHODS: The search for the relationship between the disease severity in 77 patients, 12-80 years and the distribution pattern of subfraction serum components revealed three informative zones: 6-15, 27-67, and 127-223 nm. RESULTS AND CONCLUSION: In patients without disturbances of vital functions, the contribution of the first zone particles into light scatter increases and that of the third zone particles decreases. Considerable differences attaining the level of statistical significance in zones 6 and 20 nm were revealed in the spectra of serum from patients with myasthenia gravis of the same severity with and without thymoma. This opens prospects for dynamic monitoring of the efficiency of therapy.

[Thoracoscopic thymectomy in children by myasthenia gravis].

The authors' experience of surgical treatment of myasthenia gravis in children was analyzed. 32 patients were operated on, mean age was 13±3 (5-21 years); girls were 26, boys were 6 (19%). Disease severity was IIB-IVB by the MGFA classification, all patients were on anticholinesterase and pednisolone therapy. The operation was indicated by certified neurologists, specialized in myasthenia. All patient were thoracoscopically thymectomized using left- or rightside access. There were no conversions and intraoperative complications. The operation duration was 77±23 min. The postoperative hospital stay was 6.6±3.6 (3-9) days. Excellent long-term results were achieved in 6 (25%) patients, good - in 20 (62.5%) children, no changes were registered in 2 and deterioration of myasthenia in 2 (6.25%) patients. The study proved that thoracoscopic thymectomy obtains the radicalism of open technique, proposing the easier postoperative period and being the method of choice for the surgical treatment of myasthenia gravis in children.

[Thymectomy and antibodies to acetylcholine receptors (AChR) in patients with myasthenia gravis in the early postoperative period].

Thymectomy and removal of the hyperplastic thymus have been performed in 21 patients with myasthenia. In 14 patients, thymectomy is performed through thoracoscopic access (TA), while in 7 cases through thoracotomic access (TT). The serum levels of antibodies to acetylcholine receptors (AChR) determined before and after surgery were increased in both groups of patients. Thus, thymectomy, regardless of the degree of clinical improvement in early post operative period, significantly increases the level of anti-AChR antibodies in the serum of patients in the early postoperative period compared to baseline. These changes may reflect the immune response to a stressful situation related to the traumatic surgery. It should be noted that the level of anti-AChR antibodies was significantly higher in a group of TT that may be related with a larger volume of the removed tissue.

[The use of the QMGS for quantitative assessment of the severity of movement disorders in patients with myasthenia].

The MRC scale is traditionally used for assessment of the severity of movement disorders. The patients' effort is graded on a scale of 0-5. The use of this scale is limited by subjective biases and inadequate assessment of some functions. The quantitative scale for assessment of the severity of clinical symptoms of myasthenia (QMGS) allows to evaluate pathological muscle fatigability, the main syndrome of this disease, which is important for evaluating the severity of symptoms before and after the pathogenetic treatment or when probes with the introduction of acetylcholinesterase preparations are used.

[Anti-acetylcholine receptor antibodies: effect of immunosuppressive drug therapy in patients with myasthenia gravis].

We studied anti-acetylcholine receptor antibodies (ARAb) in 25 patients with myasthenia gravis before and after the immunosuppressive drug (steroid) therapy and in 22 patients before and after thymectomy. The clinical effect after the treatment was correlated with the reduction of ARAb levels by more than 20% in 62% of patients. The ARAb levels did not change, or even increased, in 15% patients despite the improvement of their clinical state. We showed the direct correlation between the clinical improvement and the decrease of ARAb level.

[Clinical features of myasthenia related with autoantibodies to muscle specific tyrosine kinase (MuSK)].

Anti-acetylcholine receptor antibodies are detected in 80 to 90% of patients with generalized myasthenia gravis - seropositive myasthenia gravis (SPMG). Approximately 10% to 20% of patients with autoimmune MG do not have antibodies to acetylcholine receptor (AChR) - seronegative MG (SNMG). An immunological study of the blood serum of patients with SNMG revealed patients with or without antibodies to muscle specific tyrosine kinase (MuSK+ and MuSK-, respectively). A clinical study of 13 MuSK+ patients with myasthenia showed that this group was characterized by predominant affect of mimic and bulbar muscles with the rare involvement of eye movement and body muscles. In Musk+ patients with myasthenia, the clinical efficacy of antitoxin esterase drugs was minimal or absent. No unequivocal conclusion on the clinical pattern of this form of myasthenia has been made.

[Clinical and electrophysiological peculiarities of seronegative myasthenia].

Thirty-seven patients with myasthenia gravis (MG) underwent AChR-Ab analysis, clinical study and neurophysiological examination - repetitive nerve stimulation (RNS). About 16,2% of MG patients who were anti-AChR-negative constituted a so-called seronegative MG group (SNMG). Compared to the AChR-Ab positive patients (SPMG), the SNMG was characterized by the higher female/male ratio (6:1), higher frequency of infantile onset of MG (33,3%), absence of association with thymoma and highest frequency of myasthenic crisis (83,3%). The clinical pattern of SNMG differed from SPMG and was characterized by predominant affect of mimic bulbar and respiratory muscles that determined severity of the course and high frequency of myasthenic crises. The identical clinical pattern was found in 19,3% of SPMG patients. However the character of neuromuscular transmission in orbicularis oculi muscle was different in SNMG and this SPMG-group. The pathological decrement was observed in 83,3% muscles of the SPMG-group (from -20% to -74%) and only in one case in the SNMG-group (-48%). Besides, the absence of clinical and neurophysiological responses to anticholinesterase was noted in the SNMG-group. Cholinergic neuromuscular hyperactivity in SNMG patients manifested itself in clinical fasciculations and myokymic contractions of muscles which prevailed in facial muscles in 66,7% of SNMG patients. Neurophysiologic examination displayed extra repetitive discharges after the compound motor action potential (R-CMAP) at low-frequency stimulation after acetylcholine esterase inhibitors in 100% cases.

[Long-term results of surgical treatment of thymomas at the patients with generalized myasthenia].

Results of diagnosis and treatment of 150 patients with thymoma and generalized myasthenia are analyzed. The results of examination were registered before surgery, and also in 1, 3, 5 and 10 years after one. It is demonstrated that thymoma is potentially malignant tumor with risk of recurrence and requires long follow-up of patient after operation. Morphologic type and stage of tumor, severity of myasthenia are the main predictors in the prognosis of surgical treatment. Thymomectomy with excision of fatty tissue of anterior mediastinum is absolutely indicated for this severe category of patients, and it decreases the risk of tumor progression. Mortality of patients depends not only on tumor growth or recurrence but also on concomitant myasthenic disorders.

[Anti-Titin-antibodies at the patients with myasthenic and non-myasthenic thymoma].

Serum specimens from 52 myasthenic patients with thymoma of various histological characteristics and 4 patients with thymoma without myasthenia have tested for anti-Titin-antibodies titer. It has been demonstrated that organ-specific thymoma dominated at myasthenic patients, and organ-nonspecific thymoma - at the patients without myasthenia. There was no correlation between severe clinical symptoms and the level of anti-Titin-antibodies. The titer of antibodies at the patients with organ-specific thymoma was higher that at ones with organ-nonspecific thymoma, but there was no correlation between the level of anti-Titin-antibodies and histological type of organ-specific thymoma.

[Myasthenic myopathy].

We have tested clinical and electrophysiological parameters as well as sera for specific anti-titin-antibodies in 40 myasthenic patients with thymoma, 10 with late-onset and 40 with early-onset without thymoma. We have revealed the prevalence of clinical symptoms: chew and bulbar disturbances, neck and deltoideus muscle weakness in the patients with thymoma and late-onset myasthenia gravis without thymoma. These clinical peculiarities were associated with the absence of changes in duration of minimal motor unit potential after correction for synaptic lesions by proserine injections and increase of titin-antibodies level. The clinical data, along with the results of electrophysiological and immunological studies, suggest a presence of "myasthenic myopathy" in patients with myasthenia, comorbid with thymoma, and patients with late-onset of myasthenia without thymoma.

[The differential diagnostic criteria and clinical features of endocrine ophtalmopathy in patients suffering from myastenia with oculomotor disturbances].

The article covers clinical and ophthalmologic characteristics of oculomotor disturbances in myastenic patients with endocrine ophtalmopathy, and differential diagnostic signs and peculiarities of endocrine ophtalmopathy in patients with a combination of the two diseases.

[Lambert-Eatone myastenic syndrome].

A detailed comparative analysis of neurologic symptoms in 45 patients with Lambert-Eatone myastenic syndrome (LEMS) and 42 patients with generalized myasthenia allowed us to single out clinical patterns facilitating disease diagnosis and differentiation. There were no clinical differences in patients having LEMS with or without paraneoplastic process. Electromyography study revealed the presence of typical phenomena: a reduced amplitude of compound muscle action potential and incremental response at 40-Hz stimulation. The compound muscle action potential tripled after 20 s of maximal voluntary contraction. Sera from 89% of patients with LEMS contained IgG antibodies that immunoprecipitate a radiolabeled complex of a selective antagonist of P/Q type voltage-gated calcium channels. The degree of inhibition of calcium influx by patient's IgG correlated with the reduction in amplitude of the resting compound muscle action potential.