THE SWALLOWING DISORDER IN MYOTONIA DYSTROPHICA

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1 GASTROENTEROLOGY Copyright 1966 by The Williams & Wilkins Co. Vol. 50, No.4 Printed in U.S.A. THE SWALLOWNG DSORDER N MYOTONA DYSTROPHCA CHARLES 1. SEGEL, M.D., THOMAS R. HENDRX, M.D., AND JOHN COLLNS HARVEY, M.D. Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland Dysphagia occurs in myotonia dystrophical - 7 but the incidence, characteristics, and physiological basis for this dysphagia have not been fully defined. To provide further information on this subject, 12 patients with myotonia dystrophica were studied by recording pressures within the pharynx and esophagus following swallowing. The data obtained demonstrate that pharyngeal and esophageal motor abnormalities, singly or in combination, are present in these patients. The striated muscle of the alimentary canal comprising pharynx, upper esophageal sphincter, and upper one-third of esophagus was involved in all the patients, while in one-half of the patients abnormalities of the smooth muscle portion of esophagus were present as well. Materials and Methods Motility studies were performed on 12 patients with myotonia dystrophica who were being studied on the metabolic ward of the Johns Hopkins Hospital. Some of the clinical features of these patients are summarized in table 1. The patients were not selected on the basis of the presence or absence of swallowing symptoms. The diagnosis was based on the Received February 1, Accepted December 2,1965. Presented in part at the Annual Meeting of the American College of Physicians, Denver, Colorado, April, Address requests for reprints to: Dr. Thomas R. Hendrix, The Johns Hopkins Hospital, Baltimore, Maryland This investigation was supported by Training Grant T-AM-5095 and Research Career Program Award 5-K3-AM-4891 from the nstitute of Arthritis and Metabolic Diseases, United States Public Health Service; also Clinical Research Center Grant FR-35 and Vocational Rehabilitation Administration Grant RD-1746-M. 541 characteristic clinical history, the presence of "myopathic facies," swan neck, myotonia, muscle wasting, frontal baldness, and cataracts. Muscle biopsies obtained in all patients and testicular biopsies obtained in all men supported the diagnosis of myotonia dystrophica. Each patient was questioned in detail with regard to dysphagia and other symptoms of disordered swallowing. nquiries were made regarding other gastrointestinal manifestations such as abdominal pain, weight loss, diarrhea, and constipation. Manometric studies were performed in all patients during the fasting state in the supine position. Three water-filled, open tipped polyvinyl catheters (internal diameter, 1.4 rom) with the tips positioned 5 cm apart, were passed through the nose into the stomach and were connected to Sanborn differential pressure transducers (267B). Simultaneous pressures were recorded from three points by means of a multi-channel direct writing recorder. A pneumograph monitored respiratory excursions. The resting pressure within the lower esophageal sphincter was measured by stepwise withdrawal of the recording tip from stomach to esophagus. By repeated withdrawal of the three catheters from stomach to esophagus, from four to 12 technically satisfactory measurements of intrasphincteric pressure were obtained. The mean of the difference between the intrasphincteric and intragastric pressure is termed the "mean effective intrasphincteric pressure." These data were compared with the data obtained from a control group consisting of 25 patients comparable in age distribution, sex, and limitation of activity, without esophageal or neuromuscular symptoms. Pressure recordings were obtained at l-cm intervals throughout the body of the esophagus. The frequency of peristaltic response to swallowing was determined for each subject. At each level the amplitude (in millimeters Hg) and the duration (in seconds) of the peristaltic waves were measured. The peak of the peristaltic wave less the mean resting pressure was recorded as the amplitude. The mean

2 542 SEGEL ET AL. Vol. 50, No.4- TABLE 1. Clinical characteristics of patients studied Patient Age Sex Race C. S. 55 M C J. K. 52 M C H. J. 64 F N C. S. 23 M C C. P. 23 M C W.W. 39 M C T. F. 51 M C J. D. 43 M C V.L.H. 40 M N R. McK. 38 F C T. G. 60 M N R.W. 45 M C Myotonia Dysphagia Speech involvement present present present yy 43 None None 16 2 yr 5 yr 15 None None 6 None None 9 None Nasal voice most of life yr 10 yr, slurred 17 5 yr 3 yr 22 None Nasal voice last 4 yr 30 None Nasal voice most of life 14 None None 25 None Speech impediment all of life 8 U1i yr 7 yr amplitude of contraction was then calculated for each level. The duration was defined as the time in seconds required for the peristaltic wave to pass a given point (fig. 1); the mean for each patient and control was recorded. The total number of swallows and the proportion which initiated peristalsis were recorded for each of the patients. The resting pressure within the upper esophageal sphincter and the duration of relaxation of this sphincter with swallowing were determined for each patient. The mean and standard deviation of all technically satisfactory values were recorded for each patient. The mean amplitude and mean duration of pharyngeal contraction were also determined. n the same manner as outlined for the patients with myotonia dystrophica, esophageal motility studies from 12 control subjects, comparable in age distribution, sex, and limitation of activity (coronary artery disease, cirrhosis) were analyzed. None of the controls had known muscle disease or symptoms of a swallowing disorder. For the study df the lower and upper esophageal sphincter the control group was enlarged to 25 patients. The raw data from which the means were obtained are available from the authors upon request. Results The mean amplitude of the peristaltic contraction for each patient, obtained in pharynx and at centimeter intervals throughout the esophagus, was compared with the mean value obtained from the control group. The mean amplitude of pharyngeal peristaltic contraction was less in all 12 patients with myotonia dystrophic a (mean, 15.5 mm Hg ± 6.9; range, 4.2 to 26.7 mm Hg) than in the controls (mean, 46.1 ± 12.1; range, 35 to 80 mm Hg) (fig. 2). The mean duration of pharyngeal contraction in patients with myotonia dystrophica was prolonged (1.16 ± 0.45 sec; range, 0.46 to 1.9 sec) compared with the controls (0.45 ± 0.14 sec; range, 0.3 to 0.75 sec). Ten of the 12 patients had a mean duration greater than the range of the controls. n two patients (J. K. and R. McK.) prolongation was sufficient (1.9 and 1.9 sec) to suggest a myotonic response (fig. 3). The mean resting pressure of the upper esophageal sphincter in the control group was 14.3 mm Hg ± 3.5; range, 9 to 21.5 mm Hg. n the patients with myotonia dystrophica the mean upper sphincter resting pressure was 7.5 mm Hg ± 4.2; range, 2.5 to 16 mm Hg. n seven of the 12 patients with myotonia dystrophica, the mean resting pressure was below the range of the controls (fig. 4). The mean duration of relaxation of the upper esophageal sphincter in the control group ranged from 0.6 to 1.3 sec (mean, 1.0 ± 0.19 sec) compared with 1.0 to 1.9

3 April 1966 DYSPHAGA N MYOTONA DYSTROPHCA 543 sec (mean, 1.52 ± 0.19 sec) for the patients with myotonia dystrophica. All but two of the patients with myotonia dystrophica had a duration of relaxation which was greater than the range for the controls (fig. 5). The mean amplitude of peristaltic contraction was significantly reduced throughout the entire esophagus in 10 of the 12 patients. One patient (W. W.) failed to show any esophageal peristalsis in response to swallowing. The remaining patient (H. J.) demonstrated normal amplitude throughout the lower one-half of the esophagus but had a significant reduction in amplitude in the upper one-half of the esophagus (fig. 6). The duration of peristaltic contraction in upper esophagus was increased in nine of the 12 patients (fig. 7). No significant differences were noted in duration of peristaltic contraction in the lower half of esophagus. The resting pressure within the lower esophageal sphincter expressed as millimeters Hg above fundal pressure, showed no significant difference between the patients with myotonia dystrophica (range, 2.3 to 7.8 mm Hg; mean, 4.95 ± 1.93 mm Hg) and the control group (range, 1.6 to 8.0 mm Hg; mean, 5.13 ± 2.05 mm Hg) (fig. 8). n nine of the 12 patients with myotonia dystrophica, over 50% of the swallows failed to initiate peristaltic contraction compared with failure rates of 11 % in the control group (range, 76 to 100%) (fig. 9). The four patients who experienced dysphagia were among the patients with the most striking motor abnormalities. The patient whose dysphagia was most severe and of the longest duration (W. W., having dysphagia for 15 years) showed severe pharyngeal changes, diminished tone of the upper esophageal sphincter, and failure to initiate an esophageal response to any of a total of 21 swallows. Conversely, the patients who most regularly responded to swallows with a peristaltic contraction did not complain of dysphagia. Discussion Myotonia dystrophic a is an heredofamilial disorder characterized by myotonia and mm. Hg. mm. HQ. mm. Hg. Peristaltic Wove ~ o o Swallowing ~ : com~ Proximol tip Middle tip Distal tip Amplitude o Time in Seconds FG. 1. Schematic representation of peristaltic contraction demonstrating the technique employed in the calculation of amplitude and duration. The peristaltic amplitude is calculated as the peak of peristaltic contraction minus the mean resting pressure. The "swallowing complex" indicates all pressure changes from the onset of swallowing to the return of peristaltic wave to the base line. The duration of the peristaltic wave itself was computed at all levels for patients and controls yielding the data described in the text. wasting of specific muscle groups, myocardial involvement, and dystrophic changes in nonmuscular tissue.2 The occurrence of pharyngeal and laryngeal weakness has been reported but its incidence has not been defined precisely.3-7 n the group of 12 patients herein described, five had complained of dysphagia, six had laryngeal symptoms, and four had experienced periods of marked weight loss, or diarrhea, or both. The dysphagia was generally localized to the pharynx and upper esopha-

4 AMPLTUDE OF PHARYNGEAL CONTRACTONS Myotonia Dystrophica.,! :!-L o~ ~ FG. 2. Mean amplitude of pharyngeal contraction. Each point represents the mean amplitude for a patient or a control. The means and standard deviations for the two groups are indicated. DURATON OF PHARYNGEAL CONTRACTONS Controls Myotonia Oystrophica T Time 1.4 in Seconds i...! A 0: FG. 3. Mean duration of pharyngeal contraction. Each point represents the mean duration for a patient or a control. The mean and standard deviation for the two groups are indicated. 544

5 April 1966 DYSPHAGA N MYOTONA DYSTROPHCA RESTNG PRESSURE CRCOPHARYNGEUS mm. Hg ,,,.1.",....J.. mean.t. - mean CONTROL MYOTONA DYSTROPHCA FG. 4. Resting pressure within the upper esophageal sphincter. The mean is plotted for each patient and each control. The means and standard deviations are plotted for the control and myotonia dystrophica groups. DURATON OF RELAXATON OF CRCOPHARYNGEUS Time 2.0 :. T in 1(, Seconds 1.0 "",on.1.j. T.l.. mea CONTROL MYOTONA DYSTROPHCA FG. 5. Duration of relaxation of the upper esophageal sphincter. The mean is plotted for each patient and each control. The means and standard deviations are plotted for the control and myotonia dystrophica groups.

6 546 SEGEL ET AL. Vol. 50, No _ CONTRACTON = Mean of Controls 0- E E ~ :;) > > Cl c E :;) ~ c 10 O ~------~ r ' ' ' cm Above Lower Esophageal Sphincter FG. 6. Amplitude of esophageal peristaltic contraction. The means of the control group and the myotonia dystrophic a group are plotted in heavy lines. The cross-hatched areas indicate 1 SD from the mean. gus. t was accompanied by laryngeal symptoms in four of five patients, and was often associated with regurgitation of liquids into the nasopharynx. Since the human esophagus contains both smooth and striated muscle, esophageal motor studies provide an opportunity to study the effect of a given disease on both types of muscle. Schumacher,s in his meticulous anatomical studies, demonstrated that the upper one-fourth of the human esophagus consisted of striated muscle, the second fourth was a transition zone from striated to smooth muscle, and the lower half was composed of smooth muscle only. This arrangement is a fairly constant one as shown by Arey and Tremaine9 who found exclusively smooth muscle in the lower half of 73 of 74 human esophagi. ntraluminal manometric studies performed in 12 patients with myotonia dystrophica demonstrated that all patients manifested a marked reduction in amplitude of peristaltic contraction of the pharynx. Of the 11 patients demonstrating esophageal peristalsis, all had mean amplitude of contraction less than that of the controls. mpaired function in pharynx and upper esophagus is a manifestation of striated muscle involvement. n the lower one-half of esophagus (composed of smooth muscle alone) the amplitude of contraction was diminished in 10 patients. n one patient no esophageal peristalsis could be elicited. t is well recognized that myotonia dystrophica involves both striated muscle and myocardial muscle. The demonstration of abnormalities in the lower esophagus in 11 of 12 patients with myotonia dystrophic a suggests involvement of smooth muscle as well in this disease. On the other hand, these findings might also be attributed to impaired conduction of the peristaltic wave from the striated muscle

7 April 1966 DYSPHAGA N MYOTONA DYSTROPHCA 547 DURATON OF PERSTALTC CONTRACTON 8. 0 ~ , T M E N SECO N OS MEAN PONTS FOR M O. - CONTROLS o em. ABOVE LOWER ESOPH AGEAL SPHNCTE R FG. 7. Duration of esophageal peristaltic contraction. The means of the control group and the myotonia dystrophica group are plotted in heavy lines. The means of the two groups were essentially the same for the lower 10 cm of esophagus. Above this level the mean duration decreased in the control group while the mean remained at approximately the same level in the mytonia dystrophica group. The cross-hatched areas indicate 1 so from the mean.

8 548 SEGEL ET AL. Vol. 50, No.4 EFFECTVE MEAN RESTNG PRESSURE N THE LOWER ESOPHAGEAL SPHNCTER MYOTONA CONTROLS DYSTROPHCA MEAN RESTNG PRESSURE mm. Ho ABOVE MEAN NTRAGASTRC PRESSURE ~------~~ ' , ,1r r- 1 -r r~ FG. 8. Resting pressure within the lower esophageal sphincter. Each point plotted is the mean resting intrasphincteric pressure minus the gastric fundal pressure for a patient or a control. The mean ± 1 SD is indicated.

9 April 1966 DYSPHAGA N MYOTONA DYSTROPHCA 549 PERCENTAGE OF SWALLOWS FOLLOWED BY PERSTALSS Controls Myotonia Dystrophica FG. 9. Percentage of swallows followed by peristalsis. The height of each bar indicates the percentage of swallows initiating peristalsis in an individual control or myotonic subject. The number of swallows for each individual is indicated by the number within the bar. The total number of swallows and the average percentage of swallows initiating peristalsis for each group is indicated by the bars labeled "total." Total of the pharynx and upper esophagus. This latter explanation seems unlikely since in other conditions with striated muscle involvement such as dermatomyositis and myasthenia gravis, normal peristalsis is observed in the lower esophagus. Pharyngeal abnormalities were demonstrated in all patients with myotonia dystrophica, including seven of 12 who had no swallowing symptoms. The presence of symptoms correlated with increased severity of the motility disorder. ntraluminal manometry, by the quantitation of motor abnormalities, represents a parameter for serial studies of the natural course of this disorder. Summary The motor function of the pharynx and esophagus was studied in 12 patients with myotonia dystrophica. All 12 patients had diminished peristaltic amplitude in the pharynx and upper esophagus with dim inished resting tone in the upper esophageal sphincter. n addition, 10 of the 12 patients showed diminished peristaltic amplitude in the smooth muscle portion of the esophagus. This study suggests that smooth as well as striated muscle of the upper alimentary tract may be involved in this disorder. REFERENCES 1. Kramer, P., M. Atkinson, S. M. Wym tn, and F. J. ngelfinger The dynamics of swallowing.. Neuromuscular dysphagia of pharynx. J. Clin. nvest. 36: Harvey, J. C Myotonia dystrophica. Trans. Amer. Clin. Climat. Ass. 74: Slatt, B Myotonia dystrophia. Canad. Med. J. 85: Ludman, H Dysphagia in dystrophia myotonica. J. Laryng. 76: Leach, W Generalized muscular diseases presenting as pharyngeal dysphagia. J. Laryng. 76:

10 550 SEGEL ET AL. Vol. 50, No.4 6. Adams, R. D., D. Denny-Brown, and C. M. Pearson Diseases of muscle. Paul B. Hoeber, nc., New York, 735 p. 7. Brown, M. R Diseases of muscle. New Eng. J. Med. 254: Schumacher, S Die Speiserohre, p n Handbuch der mikroskopischen anatomie des menschen, Bd. 5, Teil 1. J. Springer, Berlin. 9. Arey, L. B., and M. J. Tremaine The muscle content of the lower oesophagus of man. Anat. Rec. 56: