Petr Vondráček

Risk factors for critical illness polyneuromyopathy

AbstractAlthough numerous clinical, laboratory, and pharmacological variables have been reported as significant risk factors for critical illness polyneuromyopathy (CIPM), there is still no consensus on the aetiology of this condition.Objectives of the study were to assess the clinical and electrophysiological incidence and risk factors for CIPM.A cohort of critically ill patients was observed prospectively for a one–month period and the association between neuromuscular involvement and various potential risk factors was evaluated. Sixty one critically ill patients completed the follow–up (30 women, 31 men, median age 59 years).CIPM development was detected clinically in 17 patients (27.9 %) and electrophysiologically in 35 patients (57.4 %). CIPM was significantly associated with the presence and duration of systemic inflammatory response syndrome and the severity of multiple, respiratory, central nervous, and cardiovascular organ failures. The median duration of mechanical ventilation was significantly longer in patients with CIPM than in those without (16 vs 3 days, p < 0.001). Independent predictors of CIPM obtainable within the 1st week of critical illness were the admission sequential organ failure assessment score (odds ratio [OR], 1.15; 95% confidence interval [CI], 1.02–1.36), the 1st week total sequential organ failure assessment scores (OR, 1.14; 95 % CI, 1.06–1.46) and the 1st week duration of systemic inflammatory response syndrome (OR, 1.05; 95% CI, 1.01–1.15). They were able to correctly predict the development of CIPM at the end of the 1st week in about 80% of critically ill cases.In conclusion, the presence and duration of systemic inflammatory response syndrome and the severity of multiple and several organ failures are associated with increased risk of the development of CIPM.

Mutations in the SPTLC2 Subunit of Serine Palmitoyltransferase Cause Hereditary Sensory and Autonomic Neuropathy Type I

Hereditary sensory and autonomic neuropathy type I (HSAN-I) is an axonal peripheral neuropathy associated with progressive distal sensory loss and severe ulcerations. Mutations in the first subunit of the enzyme serine palmitoyltransferase (SPT) have been associated with HSAN-I. The SPT enzyme catalyzes the first and rate-limiting step in the de novo sphingolipid synthesis pathway. However, different studies suggest the implication of other genes in the pathology of HSAN-I. Therefore, we screened the two other known subunits of SPT, SPTLC2 and SPTLC3, in a cohort of 78 HSAN patients. No mutations were found in SPTLC3, but we identified three heterozygous missense mutations in the SPTLC2 subunit of SPT in four families presenting with a typical HSAN-I phenotype. We demonstrate that these mutations result in a partial to complete loss of SPT activity in vitro and in vivo. Moreover, they cause the accumulation of the atypical and neurotoxic sphingoid metabolite 1-deoxy-sphinganine. Our findings extend the genetic heterogeneity in HSAN-I and enlarge the group of HSAN neuropathies associated with SPT defects. We further show that HSAN-I is consistently associated with an increased formation of the neurotoxic 1-deoxysphinganine, suggesting a common pathomechanism for HSAN-I.

ISPD gene mutations are a common cause of congenital and limb-girdle muscular dystrophies

Dystroglycanopathies are a clinically and genetically diverse group of recessively inherited conditions ranging from the most severe of the congenital muscular dystrophies, Walker–Warburg syndrome, to mild forms of adult-onset limb-girdle muscular dystrophy. Their hallmark is a reduction in the functional glycosylation of α-dystroglycan, which can be detected in muscle biopsies. An important part of this glycosylation is a unique O-mannosylation, essential for the interaction of α-dystroglycan with extracellular matrix proteins such as laminin-α2. Mutations in eight genes coding for proteins in the glycosylation pathway are responsible for ∼50% of dystroglycanopathy cases. Despite multiple efforts using traditional positional cloning, the causative genes for unsolved dystroglycanopathy cases have escaped discovery for several years. In a recent collaborative study, we discovered that loss-of-function recessive mutations in a novel gene, called isoprenoid synthase domain containing (ISPD), are a relatively common cause of Walker–Warburg syndrome. In this article, we report the involvement of the ISPD gene in milder dystroglycanopathy phenotypes ranging from congenital muscular dystrophy to limb-girdle muscular dystrophy and identified allelic ISPD variants in nine cases belonging to seven families. In two ambulant cases, there was evidence of structural brain involvement, whereas in seven, the clinical manifestation was restricted to a dystrophic skeletal muscle phenotype. Although the function of ISPD in mammals is not yet known, mutations in this gene clearly lead to a reduction in the functional glycosylation of α-dystroglycan, which not only causes the severe Walker–Warburg syndrome but is also a common cause of the milder forms of dystroglycanopathy.

Efficacy of pregabalin in neuropathic pain in paediatric oncological patients

OBJECTIVE To evaluate the safety and efficacy of pregabalin in the management of chemotherapy-induced neuropathic pain in patients with childhood solid tumors and leukaemia. MATERIALS AND METHODS In an open-label study, 30 children (11 boys and 19 girls; mean age 13.5 years) who were treated for solid tumors and leukaemia, and developed a painful peripheral neuropathy, were medicated with pregabalin in the daily dose of 150-300 mg for 8 weeks. RESULTS Twenty-eight patients completed the 8-week follow-up. A significant and long-lasting pain relief was noted in 86% of these patients. Median VAS score decreased by 59% at the 8th week from baseline. Adverse effects were infrequent and transient. CONCLUSION The treatment with pregabalin resulted in a significant improvement in pain symptoms. The use of pregabalin in children is off-label so far. However, this drug seems to be a safe and effective remedy, which could significantly broaden the therapeutic spectrum in paediatric oncological patients suffering from neuropathic pain.

Mutations in Czech LGMD2A patients revealed by analysis of calpain3 mRNA and their phenotypic outcome

Calpain3 (CAPN3, p94) is a muscle-specific nonlysosomal cysteine proteinase. Loss of proteolytic function or change of other properties of this enzyme (such as stability or ability to interact with other muscular proteins) is manifested as limb girdle muscular dystrophy type 2A (LGMD2A, calpainopathy). These pathological changes in properties of calpain3 are caused by mutations in the calpain3 gene. The fact that the human gene for calpain3 is quite long led us to analyse its coding sequence by reverse transcription-PCR followed by sequence analysis. This study reports nine mutations that we found by analysing mRNA of seven unrelated LGMD patients in the Czech Republic. Three of these mutations were novel, not described on the Leiden muscular dystrophy pages so far. Further, we observed a reduction of dysferlin in muscle membrane in five of our seven LGMD2A patients by immunohistochemical analysis of muscle sections.

Analysis of histopathologic and molecular pathologic findings in Czech LGMD2A patients

Limb‐girdle muscular dystrophy type 2A (LGMD2A) is an autosomal‐recessive disorder characterized by selective atrophy and progressive weakness of proximal girdle muscles. LGMD2A, the most prevalent form of LGMD, is caused by mutations in the CAPN3 gene that encodes the skeletal muscle–specific member of the calpain family, calpain‐3 (p94). We examined the histopathologic and molecular pathologic findings in 14 Czech LGMD2A patients. Analysis of the CAPN3 gene was performed at the mRNA level, using reverse transcription–polymerase chain reaction (RT‐PCR) and sequencing, and/or DNA level, using PCR and denaturing high‐performance liquid chromatography (DHPLC). Our results confirm that mutation 550delA is the most frequent CAPN3 defect in Czech LGMD2A patients (9 alleles of 28). Furthermore, we established that, in a patient with the 550delA/R490W genotype, mRNA carrying frameshift mutation 550delA was not detected, probably due to its degradation by nonsense‐mediated mRNA decay. In muscle biopsies of two LGMD2A patients, a neurogenic pattern simulating a neurogenic lesion was observed. Immunoblot analysis revealed the deficiency of p94 in all genetically confirmed cases of LGMD2A, and secondary dysferlin deficiency was demonstrated on muscle membranes in 6 patients using immunofluorescence. Thus, we find a combination of DNA and mRNA mutational analysis to be useful in the diagnosis of LGMD2A. Moreover, our study expands the spectrum of calpainopathies to cases that simulate a neurogenic lesion in muscle biopsies, and the knowledge of possible secondary deficiencies of muscular proteins also contributes to a diagnosis of LGMD2A. Muscle Nerve, 2006

Analysis of point mutations in the SMN1 gene in SMA patients bearing a single SMN1 copy

Spinal muscular atrophy (SMA) is caused by homozygous deletion of the SMN1 gene in approximately 96% of cases. Four percent of SMA patients have a combination of the deletion or conversion on one allele and an intragenic mutation on the second one. We performed analysis of point mutations in a set of our patients with suspicion of SMA and without homozygous deletion of the SMN1 gene. A quantitative test determining SMN1 copy number (using real-time PCR and/or MLPA analysis) was performed in 301 patients and only 1 SMN1 copy was detected in 14 of them. When these 14 patients were screened for the presence of point mutations we identified 6 mutations, p.Y272C (in three patients) and p.T274I, p.I33IfsX6, and p.A188S (each in one case). The mutations p.I33IfsX6 and p.A188S were found in two SMAI patients and were not detected previously. Further, evaluation of the relationship between mutation type, copy number of the SMN2 gene and clinical findings was performed. Among our SMA patients with a SMN1 homozygous deletion, we found a family with two patients: the son with SMAII possesses 3 SMN2 copies and the nearly asymptomatic father has a homozygous deletion of SMN1 exon 7 and carries 4 SMN2 copies. Generally, our results illustrate that an increased SMN2 gene copy number is associated with a milder SMA phenotype.

High frequency of SH3TC2 mutations in Czech HMSN I patients.

Laššuthová P, Mazanec R, Vondráček P, Šišková D, Haberlová J, Sabová J, Seeman P. High frequency of SH3TC2 mutations in Czech HMSN I patients.

Glaucoma drainage implants in the treatment of refractory glaucoma in pediatric patients.

PURPOSE The aim of this study is to report the clinical course, effectiveness, and safety of glaucoma drainage implants (Molteno and Baerveldt devices) in primary and secondary childhood glaucomas refractory to conventional surgical treatments and medical therapy. METHODS This retrospective study included 76 children (76 eyes) younger than 18 years who underwent glaucoma drainage device (GDD) implantation in our clinic between 1990 and 2004. The mean age at time of surgery was 6.9+/-5.3 years (range: 4 months to 17.5 years). Intraocular pressure (IOP), visual acuity, corneal diameter, axial length, intraoperative and postoperative complications, and number of glaucoma medications were evaluated. Criteria for success were defined as IOP between 7 and 22 mmHg with or without glaucoma medications, no further glaucoma surgery, the absence of visually threatening complications, and no loss of light perception. Results were compared for children with primary and secondary glaucomas. The mean follow-up was 7.1+/-6.5 years (range: 1.6 to 15.2 years). RESULTS Mean preoperative and postoperative IOP was 33.6+/-11.4 mmHg and 17.1+/-6.5 mmHg (p<0.001), respectively. Kaplan-Meier survival analysis showed cumulative probability of success: 93% at 6 months, 91% at 1 year, 82% at 2 years, 76% at 3 years, 71% at 4 years, 67% at 5 years, and 65% at 6 years. There was no difference between patients with primary (n=31 eyes) and secondary glaucoma (n=45 eyes) in terms of cumulative success (p=0.186), final IOP, number of medications, or length of follow-up. On average, the GDI surgery was successful for a mean period of 6.7 years. Fourteen eyes of 76 (18.4%) failed: 10 eyes with uncontrolled IOP, 2 eyes with retinal detachment, and 2 eyes with no light perception. Statistical regression model did not show influence of gender and previous surgery. Lower age at the time of surgery was found to be associated with higher probability of treatment failure. CONCLUSIONS Molteno and Baerveldt glaucoma drainage implants surgery seems to be safe and effective treatment for primary and secondary pediatric glaucoma refractory to the initial surgical procedure and medical therapy.Purpose The aim of this study is to report the clinical course, effectiveness, and safety of glaucoma drainage implants (Molteno and Baerveldt devices) in primary and secondary childhood glaucomas refractory to conventional surgical treatments and medical therapy. Methods This retrospective study included 76 children (76 eyes) younger than 18 years who underwent glaucoma drainage device (GDD) implantation in our clinic between 1990 and 2004. The mean age at time of surgery was 6.9±5.3 years (range: 4 months to 17.5 years). Intraocular pressure (IOP), visual acuity, corneal diameter, axial length, intraoperative and postoperative complications, and number of glaucoma medications were evaluated. Criteria for success were defined as IOP between 7 and 22 mmHg with or without glaucoma medications, no further glaucoma surgery, the absence of visually threatening complications, and no loss of light perception. Results were compared for children with primary and secondary glaucomas. The mean follow-up was 7.1±6.5 years (range: 1.6 to 15.2 years). Results Mean preoperative and postoperative IOP was 33.6±11.4 mmHg and 17.1±6.5 mmHg (p<0.001), respectively. Kaplan-Meier survival analysis showed cumulative probability of success: 93% at 6 months, 91% at 1 year, 82% at 2 years, 76% at 3 years, 71% at 4 years, 67% at 5 years, and 65% at 6 years. There was no difference between patients with primary (n=31 eyes) and secondary glaucoma (n=45 eyes) in terms of cumulative success (p=0.186), final IOP, number of medications, or length of follow-up. On average, the GDI surgery was successful for a mean period of 6.7 years. Fourteen eyes of 76 (18.4%) failed: 10 eyes with uncontrolled IOP, 2 eyes with retinal detachment, and 2 eyes with no light perception. Statistical regression model did not show influence of gender and previous surgery. Lower age at the time of surgery was found to be associated with higher probability of treatment failure. Conclusions Molteno and Baerveldt glaucoma drainage implants surgery seems to be safe and effective treatment for primary and secondary pediatric glaucoma refractory to the initial surgical procedure and medical therapy.

European Cross-Sectional Survey of Current Care Practices for Duchenne Muscular Dystrophy Reveals Regional and Age-Dependent Differences

Background: Publication of comprehensive clinical care guidelines for Duchenne muscular dystrophy (DMD) in 2010 was a milestone for DMD patient management. Our CARE-NMD survey investigates the neuromuscular, medical, and psychosocial care of DMD patients in Europe, and compares it to the guidelines. Methods: A cross-sectional survey of 1677 patients contacted via the TREAT-NMD patient registries was conducted using self-report questionnaires in seven European countries. Results: Survey respondents were 861 children and 201 adults. Data describe a European DMD population with mean age of 13.0 years (range 0.8–46.2) of whom 53% had lost ambulation (at 10.3 years of age, median). Corticosteroid medication raised the median age for ambulatory loss from 10.1 years in patients never medicated to 11.4 years in patients who received steroids (p < 0.0001). The majority of patients reported receiving care in line with guidelines, although we identified significant differences between countries and important shortcomings in prevention and treatment. Summarised, 35% of patients aged≥ nine years received no corticosteroid medication, 24% of all patients received no regular physiotherapy, echocardiograms were not performed regularly in 22% of patients, pulmonary function was not regularly assessed in 71% of non-ambulatory patients. Patients with regular follow-up by neuromuscular specialists were more likely to receive care according to guidelines, were better satisfied, and experienced shorter unplanned hospitalization periods.