Masticatory dysfunction in patients with myotonic dystrophy (type 1): a 5-year follow-up

Small bowel obstruction secondary to phytobezoar in a patient with myotonic dystrophy

A male patient in his 30s, with myotonic dystrophy (DM), presented to the emergency department with abdominal pain and vomiting. CT imaging revealed a soft tissue lesion in the terminal ileum causing small bowel obstruction (SBO). The patient underwent diagnostic laparoscopy which allowed identification and removal of the obstructing lesion. This was in the form of an intact, undigested potato, a phytobezoar. Bezoars are collections of undigested material found in the gastrointestinal (GI) tract, a phytobezoar is composed of plant material and is the most common form of bezoar. DM is a multisystem disorder characterised by skeletal muscle weakness, however it often presents with GI symptoms and the muscles of mastication are often affected. DM is a known risk factor for bezoar formation and should be considered as an important differential in DM patients presenting with SBO.

Masseter muscle volume as a disease marker in adult-onset myotonic dystrophy type 1

The advent of clinical trials in myotonic dystrophy type 1 (DM1) necessitates the identification of reliable outcome measures to quantify different disease manifestations using minimal number of assessments. In this study, clinical correlations of mean masseter volume (mMV) were explored to evaluate its potential as a marker of muscle involvement in adult-onset DM1 patients. We utilised data from a preceding study, pertaining to 39 DM1 patients and 20 age-matched control participants. In this study participants had undergone MRI of the brain, completed various clinical outcome measures and had CTG repeats measured by small-pool PCR. Manual segmentation of masseter muscles was performed by a single rater to estimate mMV. The masseter muscle was atrophied in DM1 patients when compared to controls (p<0.001). Significant correlations were found between mMV and estimated progenitor allele length (p = 0.001), modal allele length (p = 0.003), disease duration (p = 0.009) and and the Muscle Impairment Rating Scale (p = 0.008). After correction for lean body mass, mMV was also inversely correlated with self-reported myotonia (p = 0.014). This study demonstrates that changes in mMV are sensitive in reflecting the underlying disease process. Quantitative MRI methods demonstrate that data concerning both central and peripheral disease could be acquired from MR brain imaging studies in DM1 patients.

Outcome measures frequently used to assess muscle strength in patients with myotonic dystrophy type 1: a systematic review

Measurement of muscle strength is fundamental for the management of patients with myotonic dystrophy type 1 (DM1). Nevertheless, guidance on this topic is somewhat limited due to heterogeneous outcome measures used. This systematic literature review aimed to summarize the most frequent outcome measures to assess muscle strength in patients with DM1. We searched on Pubmed, Web of Science and Embase databases. Observational studies using measures of muscle strength assessment in adult patients with DM1 were included. From a total of 80 included studies, 24 measured cardiac, 45 skeletal and 23 respiratory muscle strength. The most common method and outcome measures used to assess cardiac muscle strength were echocardiography and ejection fraction, for skeletal muscle strength were quantitative muscle test, manual muscle test and maximum isometric torque and medical research council and for respiratory muscle strength were manometry and maximal inspiratory and expiratory pressure. We successfully gathered the more consensual methods and measures to evaluate muscle strength in future clinical studies, particularly to test muscle strength response to treatments in patients with DM1. Future consensus on a set of measures to evaluate muscle strength (core outcome set), is important for these patients.

Swallow-related quality of life and oropharyngeal dysphagia in myotonic dystrophy

Purpose

This study describes swallow-related quality of life (SWAL-QOL) in patients with myotonic dystrophy type 1 (DM1) and investigates its association with swallowing function and disease severity.

Methods

A SWAL-QOL questionnaire was completed by 75 DM1 patients and 25 healthy control subjects. The severity of the disease was evaluated using the muscular impairment rating scale (MIRS). Twenty-eight DM1 patients underwent a videofluroscopic swallowing examination (VFS). Spearman’s correlation coefficient was used to measure the direction and strength of associations.

Results

The SWAL-QOL median scores were significantly lower for the DM1 group than for the healthy control group. The scores for the majority of the SWAL-QOL domains were lower in patients with proximal muscular weakness (MIRS 4 and 5). Postswallow vallecular pooling and piecemeal deglutition were the most impaired VFS outcome variables.

Conclusion

Our results suggest that a multidimensional swallowing assessment is recommended for DM1 patients as SWAL-QOL and VFS measure different aspects of the swallowing function, thus providing complementary information.

Variability of multisystemic features in myotonic dystrophy type 1--lessons from Serbian registry

BACKGROUND

Myotonic dystrophy type 1 (DM1) is a rare disease. Creating registry for such a disease is of outstanding importance since it provides us with a full spectrum of the disorder.

AIM

To assess variability of different multisystemic features in a large cohort of patients with DM1.

PATIENTS AND METHOD

Data from the Serbian registry for myotonic dystrophies were used in the study. Final number of included DM1 subjects was 275.

RESULTS

Registry included 53.8% of male patients. Age at enrollment was 47.2 ± 9.9 years, mean disease duration 20.4 ± 9.9 years, and mean CTG repeats number 598.3 ± 269.8.Progression of muscle weakness was pretty slow, slower in proximal than distal muscles, and slower in arms than in legs. Severe ECG abnormality was found in 25.0% of patients and pacemaker was implanted in 9.5%. Lens opacities were observed in 83.5% of DM1 patients and 35.3% had ocular hypotony. Metabolic disturbances were very common, while 19.5% of patients had hypokalemia and 37.8% hypochloremia. Sterility was found in 20.5% of males and 4.1% of females. Cholelithiasis was found in 36.4% of patients and constipation in 29.9%.

CONCLUSIONS

We defined the most common characteristics of our DM1 patients and observed some treatable symptoms that have been neglected previously. Certain findings deserve further investigations in terms of their causes and consequences. Besides this, presented data analysis directs us to make further improvements of the registry.

Dysphagia in Duchenne muscular dystrophy versus myotonic dystrophy type 1

INTRODUCTION

In this study we aimed to demonstrate the distinctive features of dysphagia in patients with myotonic dystrophy type 1 (DM1) and Duchenne muscular dystrophy (DMD).

METHODS

Diet-type score (DTS) and maximum tongue pressure (MTP) were measured in 20 DM1 and 24 DMD patients; all patients were also examined by videofluoroscopy (VF). We used VF to measure the range of hyoid bone excursion (RHBE) during pharyngeal transit time and the area of pharyngeal residue (APR) after the first swallow.

RESULTS

RHBE and APR values for DM1 patients were significantly greater than those for DMD patients. DTS and MTP did not differ between patients. A significant correlation was observed between DTS, MTP, and RHBE in DMD patients, but not in DM1 patients.

CONCLUSIONS

Our findings reveal the differences in the distinctive features of dysphagia in DM1 and DMD. Adjustments in the diet of DMD patients in accordance with swallowing ability could be useful.