Prospective measurement of quality of life in myotonic dystrophy type 1

INTRODUCTION

Generic patient reported outcome measures have had varied success in tracking QoL in myotonic dystrophy type 1 (DM1).

AIM

To analyze changes of Individualized Neuromuscular Quality of Life questionnaire (INQoL) scores in clinic patients with DM1 over a 6-year period.

METHOD

Patients completed the INQoL at baseline and after a 6-year period through their attendance in a neurology outpatient clinic. Severity of muscular involvement in DM1 was analyzed using the Muscular Impairment Rating Scale (MIRS).

RESULTS

Ninety-nine DM1 patients completed a baseline visit. Sixty-seven of these patients were retested at an interval time. The overall INQoL score improved in our sample of patients (P<.05) as did the following subscales: myotonia (P<.05), pain (P<.05), activities (P<.01), social relationships (P<.01), and body image (P<.05). No changes were observed for the independence and emotions scales. There were no differences in mean change of INQoL scores between patients with worsened MIRS and those with no change in MIRS scale after follow-up (P>.05).

CONCLUSION

Individualized Neuromuscular Quality of Life questionnaire scores improved in our cohort of DM1 patients during a 6-year period. INQoL score did not correlate with progression of muscle weakness. This must be better understood before the selection of the instrument for use in trials to measure therapeutic benefit in DM1 patients.

Five-year study of quality of life in myotonic dystrophy

Background - Myotonic dystrophy type 1 (DM1) is the most common muscular dystrophy in adults. There is a complete lack of studies that assessed quality of life (QoL) trajectory during time in DM1 cohorts. Aim - To analyze changes of QoL in patients with DM1 during a 5-year follow-up period and to assess responsiveness of the SF-36 questionnaire. Patients and Method - At the baseline, this study comprised 84 DM1 patients, of whom 62 were retested after the mean period of 64.2 ± 3.9 months. Severity of muscular weakness was assessed using the Muscular Impairment Rating Scale (MIRS). Patients completed Serbian version of the SF-36 questionnaire as a measure of health-related QoL. Results - After 5 years, MIRS score of our DM1 patients showed significant progression of 0.5 grade (P < 0.01). All mental subdomains, role physical, and total SF-36 scores significantly improved after 5 years (P < 0.01). Unexpectedly, worsening of muscular weakness from mild to severe was in association with improvement of QoL. Conclusion - QoL improved in our cohort of DM1 patients during a 5-year period despite the progression of the disease. SF-36 should be used with caution as a patient-reported outcome measure in DM1 clinical trials.

Titin antibodies in "seronegative" myasthenia gravis--A new role for an old antigen

Myasthenia gravis (MG) is an autoimmune disease caused by antibodies targeting the neuromuscular junction of skeletal muscles. Triple-seronegative MG (tSN-MG, without detectable AChR, MuSK and LRP4 antibodies), which accounts for ~10% of MG patients, presents a serious gap in MG diagnosis and complicates differential diagnosis of similar disorders. Several AChR antibody positive patients (AChR-MG) also have antibodies against titin, usually detected by ELISA. We have developed a very sensitive radioimmunoprecipitation assay (RIPA) for titin antibodies, by which many previously negative samples were found positive, including several from tSN-MG patients. The validity of the RIPA results was confirmed by western blots. Using this RIPA we screened 667 MG sera from 13 countries; as expected, AChR-MG patients had the highest frequency of titin antibodies (40.9%), while MuSK-MG and LRP4-MG patients were positive in 14.6% and 16.4% respectively. Most importantly, 13.4% (50/372) of the tSN-MG patients were also titin antibody positive. None of the 121 healthy controls or the 90 myopathy patients, and only 3.6% (7/193) of other neurological disease patients were positive. We thus propose that the present titin antibody RIPA is a useful tool for serological MG diagnosis of tSN patients.

Significant impact of behavioral and cognitive impairment on quality of life in patients with myotonic dystrophy type 1

OBJECTIVE

To assess an impact of cognitive and behavioral impairment on QoL in a larger cohort of patients with DM1.

METHODS

Sixty six genetically confirmed DM1 patients (22 with juvenile (jDM1) and 44 with adult form (aDM1) of the disease) were recruited. Following behavioral tests were used: Hamilton scales for depression and anxiety (HamD and HamA), Daytime Sleepiness Scale (DSS), and Krupp's Fatigue Severity Scale (FSS). Patients also underwent detailed classic neuropsychological investigation and Cambridge Neuropsychological Test Automated Battery (CANTAB). Individualized Neuromuscular Quality of Life questionnaire (INQoL) was used as a measure of QoL.

RESULTS

Patients with jDM1 scored lower than aDM1 patients regarding total INQoL score and all INQoL subdomains, except for myotonia. Significant predictors of total INQoL score in patients with jDM1 were severity of fatigue (β=+0.60, p<0.01) and percentage of correct responses on Spatial Recognition Memory test from CANTAB that measures visuospatial abilities (β=-0.38, p<0.05). The most important predictors of total INQoL score in patients with aDM1 were severity of fatigue (β=+0.36, p<0.05) and level of education (β=-0.29, p<0.05).

CONCLUSION

Our results showed clear influence of different central manifestations on QoL in patients with both aDM1 and jDM1.

Dependent and paranoid personality patterns in myotonic dystrophy type 1

OBJECTIVES

To analyze frequency and type of personality pattern in patients with myotonic dystrophy type 1 (DM1), to correlate these findings with clinical data, and to assess its possible influence on quality of life (QoL).

MATERIALS AND METHODS

This cross-sectional study comprised 62 patients with DM1. Following measures were used: Muscular Impairment Rating Scale, Raven's Standard Progressive Matrices (RSPM), Millon Multiaxial Clinical Inventory I (MMCI), SF-36, and Individualized Neuromuscular Quality of Life (INQoL) questionnaires.

RESULTS

The presence of at least one pathological personality trait with score above 85 on MMCI was found in 47 (75.8%) patients. After clinical interview, 36 (58.1%) subjects had significant personality impairment. The most common personality trait in our cohort of patients was dependent found in 51.6% of patients, followed by paranoid (38.7%). Higher score on dependent personality scale correlated with lower education (rho = -0.251, P = 0.049). Dependent personality scores significantly differed between patients with physical and intellectual work (93.1 ± 8.9 vs 66.9 ± 31.7, P = 0.011). Paranoid score was higher in patients with lower education (rho = -0.293, P = 0.021), lower score on RSPM test (rho = -0.398, P = 0.004) and larger number of CTG repeats (rho = 0.254, P = 0.046). Presence of dependent personality was not in association with QoL scores (P > 0.05). On the other hand, patients with paranoid personality trait had worse QoL than those without it (P < 0.05).

CONCLUSION

Almost 60% of our patients with DM1 had clinically significant personality impairment, with dependent and paranoid personality patterns being the most common. Paranoid personality may decrease QoL in these patients, which gives us new opportunities for symptomatic therapy in DM1.

A comprehensive analysis of the epidemiology and clinical characteristics of anti-LRP4 in myasthenia gravis

Double-seronegative myasthenia gravis (dSN-MG, without detectable AChR and MuSK antibodies) presents a serious gap in MG diagnosis and understanding. Recently, autoantibodies against the low-density lipoprotein receptor-related protein 4 (LRP4) have been identified in several dSN-MG sera, but with dramatic frequency variation (∼2-50%). We have developed a cell based assay (CBA) based on human LRP4 expressing HEK293 cells, for the reliable and efficient detection of LRP4 antibodies. We have screened about 800 MG patient sera from 10 countries for LRP4 antibodies. The overall frequency of LRP4-MG in the dSN-MG group (635 patients) was 18.7% but with variations among different populations (range 7-32.7%). Interestingly, we also identified double positive sera: 8/107 anti-AChR positive and 10/67 anti-MuSK positive sera also had detectable LRP4 antibodies, predominantly originating from only two of the participating groups. No LRP4 antibodies were identified in sera from 56 healthy controls tested, while 4/110 from patients with other neuroimmune diseases were positive. The clinical data, when available, for the LRP4-MG patients were then studied. At disease onset symptoms were mild (81% had MGFA grade I or II), with some identified thymic changes (32% hyperplasia, none with thymoma). On the other hand, double positive patients (AChR/LRP4-MG and MuSK/LRP4-MG) had more severe symptoms at onset compared with any single positive MG subgroup. Contrary to MuSK-MG, 27% of ocular dSN-MG patients were LRP4 antibody positive. Similarly, contrary to MuSK antibodies, which are predominantly of the IgG4 subtype, LRP4 antibodies were predominantly of the IgG1 and IgG2 subtypes. The prevalence was higher in women than in men (female/male ratio 2.5/1), with an average disease onset at ages 33.4 for females and 41.9 for males. Overall, the response of LRP4-MG patients to treatment was similar to published responses of AChR-MG rather than to MuSK-MG patients.

Epidemiological study of adult-onset myasthenia gravis in the area of Belgrade (Serbia) in the period 1979-2008

BACKGROUND

The aim of this study was to analyze the prevalence and incidence of adult-onset myasthenia gravis (MG) in the Belgrade population from 1979 to 2008.

METHODS

Data on the number of MG patients and their basic demographic and clinical characteristics were collected from hospital records (1979-1992) and the Belgrade MG Registry (1993-2008). Incidence and prevalence were standardized by the direct method (using the world standard population). A time-trend analysis of MG incidence was performed using a linear regression model.

RESULTS

During the study period 562 cases (316 women, 246 men) were registered. On December 31st, 2008, the standardized prevalence (according to the world standard population) was 188.3/1,000,000 (women: 237.8/1,000,000; men: 139.4/1,000,000). The average annual standardized incidence rate was 13.3/1,000,000 (women: 14.1/1,000,000; men: 12.2/1,000,000). The incidence rates tended to increase significantly in both sexes during the study period (y = 3.299 + 14.363x, p = 0.002). Age-specific incidence rates for women demonstrated a bimodal pattern, with the first peak in the 20- to 29-year age group and the second one in the ≥70-year group. For both genders, an increase in age-specific incidence rates was registered for all age groups, although this was significant (p = 0.001) only for an MG onset of ≥60 years of age.

CONCLUSIONS

The study confirms an increase in the incidence of MG in the area of Belgrade during the study period, especially for those with MG onset after 60 years of age.

Validation of Serbian version of the disease-specific myasthenia gravis questionnaire

AIM

The aim of this study was to validate translated and cross-cultural adapted Italian version of myasthenia gravis-specific questionnaire (MGQ) in Serbian MG patients.

MATERIALS AND METHODS

The questionnaire was validated in 140 consecutive MG patients from Belgrade. In each patient association between the total MGQ score and form and severity of the disease was determined. Also, correlation between regional domain scores of MGQ and main clinical findings according to Besinger's clinical score was analyzed.

RESULTS

Patients' participation in the assessment was satisfactory with excellent internal consistency and reproducibility. Total MGQ score, as well as domain scores, correlated with highly significant inverse relationship with the disease severity and clinical status of patients at the moment of completing the questionnaire. Furthermore, the bulbar domain of the questionnaire appeared more specific and sensitive than clinical history and examination.

CONCLUSION

We concluded that the Serbian version of the MGQ may be useful as a measure of clinical outcome in patients with MG.

Health-related quality of life in patients with myotonic dystrophy type 1 and amyotrophic lateral sclerosis

The aim was to assess factors that might influence health-related quality of life (HRQoL) in patients with two different neuromuscular disorders - myotonic dystrophy type 1 (DM1) and amyotrophic lateral sclerosis (ALS). A cross-sectional study was performed on 79 patients with DM1 and 74 with ALS. The HRQoL was evaluated by SF-36, Serbian version. Depressive and anxiety symptoms were assessed using the Hamilton rating scale for depression and the Hamilton rating scale for anxiety respectively. Severity of muscular involvement in DM1 was measured with MRC scale and severity of ALS with ALSFRSr score. The mean total score as well as all domain scores of SF-36 were similar in DM1 and ALS patients (p > 0.05), except that ALS patients experienced less bodily pain (p < 0.05). Depressiveness was found in 51% and marked anxiety in 38% of DM1 patients. Emotional status and severity of muscular involvement emerged as significant independent contributing factors to the total SF-36 in DMI patients (p < 0.05). Only 3% of ALS patients showed depressiveness and 4% anxiety symptoms. The factors found to contribute to HRQoL in ALS patients were severity of disease and educational level ofpatients (p < 0.05). We found significant percentage of potentially treatable emotional disturbances which together with severity of disease significantly contributed to HRQoL in DM1 patients. On the other hand, in ALS patients depressiveness and anxious symptoms were uncommon and the factors found to contribute to HRQoL were severity of disease and educational level.

Leptin and the metabolic syndrome in patients with myotonic dystrophy type 1

OBJECTIVES

To evaluate serum leptin concentration and its relation to metabolic syndrome (MSy) in non-diabetic patients with myotonic dystrophy type 1 (DM1).

MATERIALS AND METHODS

This study included 34 DM1 patients, and the same number of healthy subjects matched for age, sex and body mass index (BMI).

RESULTS

DM1 patients had increased BMI and insulin resistance, and increased leptin and insulin concentrations, but the other features of MSy such as diabetes, glucose intolerance and hypertension were not detected in DM1 patients. Serum leptin levels were higher in patients with DM1 than in healthy controls (8.5 +/- 6.6 ng/ml vs 3.6 +/- 2.9 ng/ml in men, and 13.9 +/- 10.0 ng/ml vs 10.9 +/- 6.9 ng/ml in women, respectively). In DM1 patients, leptin levels correlated with BMI, fasting insulin and insulin resistance (HOMA) (P < 0.01).

CONCLUSIONS

The leptin overproduction correlated with insulin resistance in DM1 patients but the significance of this finding remains unclear.

Cyclosporine in the treatment of myasthenia gravis

Cyclosporine A (CsA) treatment was evaluated in 52 patients with severe generalized myasthenia gravis (MG) whose illness was not controlled by anticholinesterase drugs, thymectomy, corticosteroids, and azathioprine. The efficacy of CsA treatment was expressed by mean disability score quotient (MDSQ), which was obtained by comparing mean disability score (MDS) at the beginning of the treatment with the MDS at the end of the follow-up period. For the entire group of patients MDSQ was 53.3%, indicating moderate improvement. Analyzing individual cases, eight patients (15%) did not improve, 17 (33%) showed moderate improvement, 20 (38%) showed remarkable improvement, and seven patients (14%) achieved complete remission. The most common side effects were rise of serum creatinine (seven), hypertension (two), gingival hyperplasia (two), hypertrichosis (six), myalgia (10), and 'flu-like' symptoms (10 patients). The results of this study suggest that CsA is efficacious and safe treatment in severe and resistant forms of MG.