LECTURES AND REVIEWS
Duchenne muscular dystrophy is a genetic orphan neuromuscular disease caused by a mutation in the DMD gene encoding the protein dystrophin. As a result of developing and progressive muscle damage and atrophy, children lose the ability to walk, develop respiratory and cardiac disorders. The core elements of good care standards are early diagnosis, prevention and treatment of osteoporosis, daily physical therapy, regular rehabilitation, glucocorticosteroids, and control of heart and lung function. The clinical effect of new targeted pathogenetic therapies for Duchenne muscular dystrophy, restoring synthesis of full or truncated dystrophin, depend on their appropriate combination with existing standards of care.
Neuropathic pain affects 7 % of the general population worldwide, it is often resistant to analgesic treatments and is complicated with depressive states in 57–65 % of this patients’ cohort. Ongoing research of current therapeutic approaches, including repetitive transcranial magnetic stimulation (rTMS) use in neuropathic pain and depression, grants new data about the details of treatment protocols’ designs. The aim of our literature review was to evaluate those parameters of the treatment protocols which proved significant efficacy in the management of the neuropathic pain with comorbid depression.
Focusing on the Scopus, Elsevier and PubMed databases search, we have found 639 peer‑review articles. 23 studies have been included into the data analysis, whereas others were excluded based on their heterogeneous study design. Across the data analysis we evaluated such rTMS parameters as the type of a coil, type of stimulation area, locus of gained evoked motor potential, amplitude of stimulation, duration of session, frequency/number of sessions per day/month, tie duration between sessions, number and frequency of trains, amount and frequency of pulses containing and efficacy of treatment. Those studies that performed repetitive transcranial magnetic stimulation using the figure‑of‑8 coil over the M1 brain area, for 10 or more daily sessions with duration from 7 up to 40 minutes, of 10–20 Hz frequency, intensity 80–90 % of resting motor threshold and total pulses number over 1500 per session demonstrated the greater efficacy in pain level decrease and depression scores reduction among neuropathic pain patients with comorbid depression. Conducting an additional maintenance phase of treatment prolonged the therapeutic effect of the course.
Based on the data review, the parameters of the most efficient rTMS protocols’ designs in management of patients with neuropathic pain and comorbid depression have been revealed. Further research requires investigation of other promising indicators of rTMS efficacy use in neuropathic pain with comorbid depression, such as stimulation over multiple brain areas, the duration/timing of additional maintenance phase of treatment, and the figure‑of‑8 coil orientation options.
Rubinstein–Taybi syndrome is a multisystem pathology characterized by mental retardation and delayed physical development in combination with a set of phenotypic features, which make up a recognizable pattern of the disease. This review of the literature highlights the molecular‑genetic basis and the presumed pathogenesis of the Rubinstein–Taybi syndrome, considers questions of geno‑phenotypic correlations and differential diagnosis in the group of pathologies called chromatinopathies.
ORIGINAL REPORTS
TRPV4‑associated neuromuscular diseases represent a clinical spectrum of neuropathies and motor neuron disorders. To date, 3 phenotypic forms are distinguished. There are Charcot–Marie–Tooth disease type 2C, distal hereditary motor neuropathy type 8 (DHMN8), scapulo‑peroneal spinal muscular atrophy (SPSMA). Here we report 3 families with DNMN8 and one family with SPSMA. In all cases, DNA‑analysis revealed single nucleotide variants in the TRPV4 gene previously reported as pathogenic. In 3 probands, a combination of signs of both motor and motor‑sensory neuropathies led to difficulties in the establishment of the clinical diagnosis. Patients had mild sensory disturbances in the feet, but in all of these cases nerve conduction study revealed normal sensory nerve action potentials. Considering the prevailing signs of motor neuropathy, these patients were diagnosed with DNMN8. Clinical signs of sensory disturbances are regarded as not contradicting the diagnosis, since they can be observed in various forms of distal motor neuropathies. The clinical features of SPSMA in one patient corresponded to those previously described in the literature. The involvement of the shoulder girdle muscles and the peroneal muscles and neurogenic changes in needle electromyography allow suspecting SPSMA clinically. A distinctive features of TRPV4‑associated neuromuscular diseases are the vocal cords paresis, sensorineural hearing loss and respiratory failure, however they are not obligatory according to our clinical reports.
Background. Primary hypertrophic osteoarthropathy is a rare genetically heterogeneous disease with three clinical variants. The classic one is a combination of hyperostosis, arthropathy and pachyderma and two variants with damage to only bone structures or pachyderma. Two genes responsible for the occurrence of primary hypertrophic osteoarthropathy have been identified: HPGD (debut age up to one year) and SLCO2A1 (debut in puberty and adolescence), whose products are involved in prostaglandin E2 metabolism. Two recurrent variants were identified in the HPGD gene: c.175_176delCT(p.Leu59fs) in patients from Europe and c.310_311delCT in patients from China. There were no clinical and genetic correlations in patients with different variants in the identified genes, which may be due to a small number of observations. The analysis of clinical manifestations in patients with newly identified variants or previously unidentified combinations of variants in a compound‑heterozygous state helps to understand the pathogenesis and prognosis of the course of the disease.
Aim. To present the clinical and genetic characteristics of two Russian patients with primary hypertrophic osteoarthropathy caused by a newly identified combination of nucleotide variants in a compound‑heterozygous state in the HPGD and SLCO2A1 genes.
Materials and methods. Clinical examination, radiography of the skeleton and chest, electrocardiography, echocardiography. Confirmation of the pathogenicity of the identified variants and clarification of the type of disease was carried out using automatic Sanger sequencing.
Results. The clinical and genetic characteristics of two unrelated patients with primary hypertrophic osteoarthropathy caused by an undescribed combination of variants in the compound heterozygous state in the HPGD and SLCO2A1 genes were analyzed. In a patient with variants in the SLCO2A1 gene, the disease debuts at the age of 14 with deformities of the fingers, nails on the hands and feet, followed by the addition of burning pain in the distal parts of the arms and legs. At the age of 33, the examination revealed deformity of the fingers of the hands and feet by the type of drumsticks and nails by the type of watch glasses, enlargement of the knee joints, pronounced arthralgia. There were no signs of pachyderma. The new generation sequencing revealed two variants in the SLCO2A1 gene c.764G>A(p.Gly255Glu) in exon 6 and c.1333C>T(p.Arg445Cys) in exon 10. These variants were identified earlier in a compound‑heterozygous combination with other variants in patients with the classical phenotype of the disease, which were not present in the patient we observed. A feature of the case was pronounced hyperhidrosis and burning pain in the extremities, which may be due to stimulation of nociceptors in the musculoskeletal structures.
Deformities of the fingers, nails of the hands and feet occurred in a patient with variants in the HPGD gene at 6 months. At the age of 9 years, a change in shape, stiffness and arthralgia of the knee and elbow joints without pachyderma were revealed. The identified variant with c.175_176delCT(p.Leu59fs) in this gene is often found in patients from European countries, and the other is c.1A>G(p.Met1?) discovered for the first time.
Conclusion. The results allow us to conclude that when we found combinations of two variants in the HPGD and SLCO2A1 genes, there will be no pachyderma in the spectrum of clinical manifestations of primary hypertrophic osteoarthropathy. Sequencing of the new generation exome is the optimal diagnostic method.
Background. Marcher’s digitalgia paresthetica is a neuropathy of the medial plantar proper digital nerve (nervus digita lis plantaris proprii medialis halluci) and in some cases is accompanied by the formation of Joplin’s neuroma. Despite the general population rarity, marcher’s digitalgia paresthetica is significantly common among the special military contingent, athletes and tourists.
Aim. To assess the prevalence of medial digital nerve neuropathy among military personnel and to identify possible factors contributing to its development.
Materials and methods. The study involved 125 male servicemen of the Russian Federation, with an average age 37 (37–40) years. A neurological examination was performed with a detailed assessment of sensory disorders in the lower extremities, electroneuromyography and ultrasound examination of the leg nerves.
Results. In 83 cases, or 66 (55–76) %, of digitalgia paresthetica were identified. Among them asymptomatic – 51 people, or 61 (47–74) %. In 27 cases – 33 (21–47) % – violation of sensitivity was observed on one side. The maximum area of violation of the sensitivity of the innervation of the medial‑plantar surface of the big toes was determined in 57 cases – 68 (55–80) %. At the same time, in 14 (6–25) % of the examined, the distal part of the second toe was additionally involved.
Conclusion. In our study, the hypothesis about the influence of the type of footwear, the average daily duration of wearing and the frequency of its forced removal on the likelihood of developing paresthetic digitalgia was not confirmed. It is important that doctors are informed about the possible development of this neuropathy and its benign course.
CLINICAL DISCUSSION
Necrotizing myopathies are a subtype of autoimmune myopathies characterized by muscle fiber necrosis with minimal infiltration by inflammatory cells on muscle biopsy. This group of myopathies is defined by flaccid palsies due to prima‑ ry skeletal muscle damage as well as extramuscular manifestations such as fever, rash, arthritis, Raynaud’s syndrome and interstitial lung disease. The presence of anti-SRP antibodies is associated with rapidly progressive refractory myositis predominantly affecting limb muscles and axial muscles.
Objective of the work is to analyze the course of severe, refractory to several lines of immunosuppressive therapies anti-SRP associated necrotizing myopathy and to highlight an adequate treatment regime.
Necrotizing myopathy was suspected in patients aged 39 and 56 years with rapidly progressive flaccid tetraparesis on the basis of clinical and anamnestic data, the results of needle electromyography and muscle magnetic resonance imaging, as well as the analysis of myositis-specific and myositis-associated autoantibodies. In both cases, a rapid development of atrophies, marked muscle weakness in the limbs, without involvement of the bulbar musculature, was observed. To achieve effective control of the disease progression, several lines of therapy were required: glucocorticosteroids, intravenous immunoglobulins, methotrexate and rituximab. Our observations are consistent with those in the literature.
Our observations illustrate the clinical course of severe myopathy associated with anti-SRP antibodies. Early initiation of aggressive immunosuppression is crucial to control the disease progression. Treatment and rehabilitation allow achieving significant improvement of the patient’s condition.
CONFERENCES, SYMPOSIUMS, MEETINGS
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