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Anal Sphincter Abnormalities Characteristic of Myotonic Dystrophy
Vol. 49, No.6 Printed in U.S.A.
GASTROENTEROLOGY
Copyright
© 1965 by The Williams & Wilkins Co.
ANAL SPHINCTER ABNORMALITIES CHARACTERISTIC OF MYOTONIC DYSTROPHY MARVIN M. ScHUSTER, M.D., DoNALD
E.
Tow, M.D., AND DoNALD
H.
SHERBOURNE, M.B.
Department of Medicine, Baltimore City Hospitals, and The Johns Hopkins University School of Medicine, Baltimore, Maryland
Myotonic dystrophy is a familial disorder of unknown etiology characterized by fron.tal baldness, cataracts, testicular atrophy · and myotonia of skeletal muscle with progressive wasting and weakness. Myotonia may be demonstrated following voluntary contraction with inability to relax the grip after a strong handshake, or mechanically by percussion of the muscles of the thenar eminence. Smooth muscle involvement is less well appreciated in this disorder. In order to assess the effect of myotonic dystrophy upon the smooth and striated muscles of the anal sphincter, separate pressure recordings were simultaneously obtained from the internal anal sphincter, which is composed of smooth muscle, and the external anal sphincter, which is composed of striated muscle. Materials and Methods Two groups of subjects were studied. The first group consisted of 25 normal subjects without gastrointestinal complaints or disease referable to the colon. These were volunteers who either had no known disease, or whose disease, such as pneumonia, was restricted to an organ system other than gastrointestinal. In addition, seven patients with the established diagnosis of myotonic dystrophy were studied from the Received March 5, 1965. Accepted July 9, 1965. Address requests for reprints to: Dr. Marvin M. Schuster, Baltimore City Hospitals, 4940 Eastern Avenue, Baltimore, Maryland 21224. This investigation was supported by Research Grant AM 06352-02 from the National Institute of Arthritis and Metabolic Diseases, and 5 MO 1 FR-35 from the General Clinical Research Center, United States Public Health Service. The authors are grateful to Dr. John C. Harvey for permission to study his patients. 641
Adult Muscle Clinic of The Johns Hopkins Hospital. There were six males, one female. Five of the patients were white, two Negro. Ages ranged from 25 to 66 years, with an average of 45. All had advanced myotonic dystrophy with moderately severe muscle wasting. None was receiving medication. Bowel habits were normal in all but two of the patients, who had moderate constipation. Pressures were recorded separately from the rectum, the internal anal sphincter and the external anal sphincter by a technique previously described.' No premedication or bowel preparation was employed. Recordings were made: (a) during rest, (b) during transient distension of the rectal balloon by 50 cc of air, (c) during maximal voluntary contraction of the anal sphincter, and (d) with balloon distension superimposed upon sustained maximal voluntary contraction. In addition, studies were performed during cutaneous stimulation by perianal pin scratch. The pressure-sensing device consisted of a hollow steel cylinder (fig. lA) around which a double balloon (fig. lB) was tied, creating two separate compartments. Sixteen-gauge needles were soldered to the inner surface of the cylinder and brought to the outer surface, one opening into each balloon compartment. With the subject lying in the left lateral position the metal cylinder with both balloons deflated was inserted into the anal canal in such a manner that, when each balloon was distended with 15 cc of air, the internal balloon was surrounded by the internal sphincter and the external balloon by the subcutaneous bundle of the external sphincter (fig. 2). A Miller Abbott balloon of 50-cc capacity was inserted through _the hollow bore of the metal tube to a depth of 10 em in the rectum. The balloons were connected via polyethylene tubing to pressure transducers (Sanborn model no. 267 B). Tracings were recorded on three channels of a direct writing recorder (Sanborn model 934). A pneumographic tracing on the fourth channel monitored respirations and body movements.
642
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Vol. 49, No. 6
B
FIG. 1. Pressure sensing device. A, Hollow steel cylinder with two 16-gauge needles soldered to inner core and opening to surface. B, Double balloon tied around cylinder, creatmg two separate compartments. One needle communicates with each compartment. Polyethylene tubing connects needles to pressure transducers. (Reprinted with permission of the editors and publishers, Bull. Hopkins Hosp. 116: 79, 1965.)
Results Resting state. In normal subjects a steady base line was observed in the resting state. In contrast, four out of the seven patients with myotonic dystrophy demonstrated a spontaneous cyclical contraction and relaxation which was recorded from both the internal and external sphincter balloons (fig. 3). This spontaneous activity was episodically present for approximately onehalf of the recording time. Transient distension. In normal subjects, transient distension of the rectal balloon with 50 cc of air produced relaxation of the internal sphincter and contraction of the external sphincter (fig. 4). The average pressure fall in the internal sphincter was 25 mm Hg and the average duration of relaxation was 15 sec. In patients with myotonic dystrophy two patterns of response to rectal distension were noted. In one, a myotonic contraction of high amplitude and
markedly prolonged duration was seen in both the internal and external anal sphincters (fig. 5A). The internal sphincter did not relax, but instead, after a short delay, it underwent a tonic contraction. The external sphincter had an initial, apparently normal contraction; after a brief delay it then had a tonic contraction of high amplitude and prolonged duration. No contraction was seen in the rectum. In the second type of response the internal sphincter relaxed in normal fashion but then contracted tonically as shown by the sustained rise above resting level (fig. 5B). Both patterns of response (fig. 5A, B) were present in four patients. Two patients had only the pattern illustrated in figure 5A, and one patient only the type illustrated in figure 5B. The relaxation averaged 22 mm Hg in amplitude (range, 6 to 40 mm.) and 10 sec in duration (range, 8 to 20 sec). Contraction of the internal sphincter averaged 22 mm Hg in
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MYOTONIC DYSTROPHY
amplitude (range, 10 to 45 mm) and 35 sec in duration (range, 10 to 50 sec) . The external sphincter also underwent tonic contraction averaging 18 mm Hg in amplitude and 28 sec in duration (fig. 6A, B). Voluntary contraction. In normal subjects voluntary contraction of the anal sphincter produced a sharp rise in base line in both sphincter balloons (fig. 7A). If the rectal balloon was distended while contraction was maintained, the internal sphincter relaxed in normal fashion, whereas no further contraction appeared in the external sphincter. A similar response was seen in patients with myotonic dystrophy (fig. 7B). Pressure dropped abruptly (without myotonia) to resting level when voluntary sphincter contraction suddenly ceased. Perianal pin scratch. Scratching the perianal skin of normal subjects with a pin produced contraction of the external sphinc-
+I~~~· ~. -ro]. -~- ~
Rectum
::oi t4
+30
..
Int. Sphinct .
+20
I
+10
(.)
0
c.
:z: + 15 E
+10
E + 5
0
Ext. Sphinct.
- 5
-ro 0
20
40
60
80
100
120
140
Time in Seconds
FIG. 3. Spontaneous cyclical contraction in myotonic dystrophy. In this and in subsequent tracings, pressure change in the balloons is recorded on the vertical axis in millimeters of mercury.
''~L.t-A_~~-vv - 10 I---- . -- Rectum
('~rt II"'\~ Int. Sphinct. !
..r. -10 0
.,;.
J
-zo
I
J: -30
-40
Rectal -- -
btdloon
~ :'~ 1
h
Ext. Sphinct.
-5~1l 0
20
40
60
80
Time in Seconds
FIG. 2. Schematic diagram of recording technique. Metal cylinder with attached double balloon lies in anal canal so that, when inflated, the internal sphincter balloon is surrounded by the internal sphincter and the external sphincter balloon by the subcutaneous bundle of the external sphincter. Note overlap of internal sphincter by deeper bundles of external sphincter. Rectal balloon lies in rectum. (Reprinted with permission of the editors and publishers, Bull. Hopkins Hosp. 116 : 79, 1965.)
FIG. 4. Transient rectal distension m normal subject. In this and in subsequent pressure tracings distension of rectum is indicated by arrows over t ime axis. Upgoing arrow indicates inflation, and do wn going arrow, deflation of rectal balloon. Resting pressure in each balloon is assigned a zero value. Pressure increase above resting level is designated as positive and decrease below this level as negative. R ectal distension (arrows ) produced transient relaxation of internal sphincter and contraction of external sphincter. (Reprinted with permission of the editors and publishers, Bull. Hopkins Hosp. 116: 79, 1965.)
ter (fig. 8A). The average amplitude of contraction was 12 mm Hg and the average duration was 5 sec. In patients with myotonic dystrophy a contraction of high amplitude and prolonged duration was elicited (fig. 8B). The amplitude averaged 30 mm Hg and the duration averaged 20 sec (fig. 6).
644
SCHUSTER E1' AL.
Vol. 49, No. 6
+1~1~
Rectum
;~r~-
Rectum
•20
+ 10
..
+'lO~
+20
Int. Sphinct.
~ -+10
~
0
t• 0~
u
-20
!f•25~ ~ + 15 + 10
4
+30 E •20 E • 10
A
-10
+ 20
(.) -10
-I~
Int. Sphinct.
0
j
Ext. Sphinct.
+
Ext. Sphinct.
5 0
1~ 0204060 80 T ime in Seconds
-
5
1l 0
8
20 40 60 Time in Seconds
80
FIG. 5. Two patterns of response found with transient rectal distension in mvotonic
dys~rophy. A, Contraction of high amplitude and prolonged duration is seen in both internal sp~I~cter
and external sphincter. Internal sphincter failed to relax. (Reprinted with perllllSSIOn, Amer. J. Med. 39: 81, 1965). B, Normal relaxation of internal sphincter was followed by myotonic contraction. Myotonic contraction of external sphincter occurred simultaneously wit~ relaxation . of internal sphincter. By the time that myotonic contraction appeared m mternal sphmcter, the pressure in external sphincter had returned to resting level.
Discussion
Abnormalities of the gastrointestinal tract, generally muscular weakness or disordered peristalsis, have previously been demons.t~ated in myotonic dystrophy. Abnormalities of esophageal motility have been described fluoroscopically. 2 -5 More r~cently, studies of the swallowing mechamsm by manometric and cineradiographic techniques have demonstrated weakness of striated muscle of the pharynx and disordered peristalsis of smooth muscle of the esophagus. 6 - 7 Similar findings of dilation and delayed motility have been described in the small bowel. 8 Cardiospasm has also been recorded as well as ptosis and delayed emptying of the stomach and colon.9 However, with the exception of a recent review including the present studies, 10 the authors concluded that there was no evidence for myotonia in the smooth muscle of the gastrointestinal tract. The present investigation demonstrates myotonia of both the smooth and striated muscle of the anal sphincter. The episodic cyclical contractions seen in ~our of th~ seven patients were noted only m myotome dystrophy and were not found in a large number of other conditions
studied. The significance of this finding is not known. Anatomical relationships in the anal sphincter raise the question whether the pressure rise recorded from the internal sphincter balloon represents contraction of the internal sphincter (smooth muscle) or of the deeper bundles of the external sphincter (striated muscle) which surround the internal sphincter (fig. 2). Although the patterns of response seen in figure 5A are not too different in the internal and external sphincters, the response of each sphincter is quite different in figure 5B. Here the internal sphincter relaxed in normal fashion but then contracted tonically, while the external sphincter underwent tonic contraction of such high amplitude that the writing stylus went off the recording paper. The myotonic contraction of the internal sphincter can be seen to be clearly separate from, and independent of, the myotonic contraction of the external sphincter. In fact, the myotonic response did not appear in the internal sphincter until it had disappeared from the external sphincter. It is, therefore, apparent that the myotonic contraction recorded in the internal sphincter balloon cannot be explained as a reflection of con-
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645
MYOTONIC DYSTROPHY
AMPLITUDE OF RESPONSES RECTAL DISTENSION INTERNAL SPHINCTER I
~I
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~J~TION
PERIANAL SCRATCH
EXTERNAL SPHINCTER
EXTERNAL SPHINCTER
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CONTRACTION
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~
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· M.D.
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DURATION OF RESPONSES RECTAL Dl STENSION INTERNAL SPHINCTER RELAXATION
.---'---1
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~
EXTERNAL
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SP~ER
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~DYSTROPHY
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~ 30
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~MO.
Fw. 6. Quantitative comparison of sphincter responses in normals (light bars) and myotonic dystrophy (shaded bars). A, Amplitude of responses. Note that the greatest difference between the two groups lies in the contractile response of the internal sphincter, the smooth muscle (second pair of bars). B, Duration of response. A comparison of a and b demonstrates a greater difference between normals and myotonic dystrophy in duration than in amplitude of response. The most pronounced difference is again seen to be in internal sphincter contraction (second pair of bars) .
traction of the deeper bundles of the external sphincter. It has been previously demonstrated that voluntary effort may alter the response of the striated muscle, the external sphincter, but not affect the response of the smooth muscle, the internal sphincter (fig. 7A) .1 • 11 It is of interest that the response was normal when distension was superimposed upon voluntary contraction in a myotonic patient
(fig. 7B). Another feature demonstrated by figure 7B is severe weakness in the external sphincter in myotonic dystrophy manifested by the sloping drop in pressure in the external sphincter balloon. This finding is compatible with the poor tone and profound weakness of the anal sphincter on digital examination of these patients. Also of importance is the fact that patients were able to relax the sphincter on command
SCHUSTER ET A L.
646
t40l
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•
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20 40 60 80 TIME I N SECO NDS
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8
Int. Sphinct.
~
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EXT. SPH I NCT
,A "\
o
A
Vol. 49 , No.6
---40
Time in
60
80
100
Seconds
FIG. 7. Rectal distension superimposed upon voluntary sphincter contraction. A , Normal subjects (black bar indicates duration of voluntary contraction). Internal sphincter relaxed with rectal distension (arrows), despite voluntary effort to maintain contraction (black bar). Rectal distension produced no alteration in external sphincter. (Reprinted with permission of the editors and publishers, Bull. Hopkins Hosp. 116: 79, 1965.) B, Myotonic. dystrophy. No myotonic response is seen when rectum was distended during voluntary contraction of sphincter.
.,o0 L .. .
r--~_J._~-~ Rectum
+I~ l.~--·
_,o r-
~·~o~ 0
§
.r:; 0
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t3
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Int. Sphinct.
E +40
-~ Ext. Sphinct.
+20 +10
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t 0
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0
- 5
'
+10
0. +6 0 I +5 0
-10
t+IO~ E + 5
~:~~u~ ~
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20
A Time in Seconds
B
t 0
20 40 60 Time in Seconds
FIG. 8. Perianal pin scratch. A, Normal subj ects. Brief contraction of external sphincter appeared with perianal scratch (arrow). (Reprinted with permission of the editors and publishers, Bull. Hopkins Hosp. 116: 79, 1965.) B, Myotonic dystrophy. External sphincter contraction of high amplitude (50 mm Hg) and prolonged duration (25 sec) was produced by perianal scratch.
(fig. 7B), demonstrating absence of myotonia under conditions of voluntary sphincteric contraction. This finding is consistent with the clinical observation that mechanically induced myotonia (here induced by balloon distension) may be present when voluntary myotonia is not present. 9 The myotonic pattern seen in the ex-
ternal sphincter response to pin scratch (fig. 8B) is analogous to myotonia induced by percussion of hypothenar muscles. The contraction reflected in the internal sphincter balloon is probably due to the deeper bundles of the external sphincter which surround the internal sphincter balloon (fig. 2). External sphincter contraction was ap-
December 1965
647
MYOTONIC DYSTROPHY
parently recorded in the internal sphincter balloon when the external sphincter contracted without a corresponding alteration of tone in the internal sphincter. This phenomenon can best be illustrated in patients with scleroderma in whom the internal sphincter response is absent. 12 In these patients contraction of the external sphincter is recorded in the internal sphincter balloon when the rectum is distended or when the perianal skin is scratched. Amplitude and duration of response were analyzed quantitatively (fig. 6). Approximately five complexes were averaged for each individual. Although (as demonstrated by the height of the bars) there was significant quantitative variation between individuals, the results in a given subject were quite reproducible. In the external sphincter (fig. 6A, pair of columns on the right) there was a uniform slight increase in amplitude of contraction in myotonic dystrophy as compared to the normal, whether stimulation was by perianal scratch or rectal distension. The major difference between the myotonic and the normal group lay in the response of the internal sphincter (second pair of columns on the left). Whereas in the normal subject rectal distension produced only relaxation and no contraction, a strong contraction either replaced or followed relaxation of the internal sphincter in patients with myotonic dystrophy. While the amplitude of internal sphincter contraction did not overlap, the duration of internal sphincter relaxation was similar in the two groups (fig. 6B, pair of columns on the left). However, when the sphincter contraction was compared (last three pairs of bars) the response was of appreciably longer duration in myotonic dystrophy than in normal subjects. Here again, the greatest difference between the two groups lay in the internal sphincter response (second pair of columns). A contraction of prolonged duration was found in myotonic dystrophy, but not in normal subjects. These numerical results were subjected to statistical analysis by means of the t-test. There was no significant difference between the normal and myotonic dystrophy groups in terms of either amplitude or duration of relaxation of the internal
sphincter. By inspection there was a wide difference between the two groups in both amplitude and duration of contractile response of the internal sphincter. The difference in external sphincter contraction between these groups was statistically significant whether stimulated by rectal distension (for amplitude, P < 0.05; for duration , P < 0.01) or by perianal scratch (for amplitude, P < 0.01; for duration, P < 0.05). Summary
Manometric studies of anal sphincteric responses to rectal distension, perianal pin prick and voluntary contraction, were performed in 25 normal subjects and seven patients with myotonic dystrophy. In the normal subjects balloon distension of the rectum produced relaxation of the internal sphincter and contraction of the external sphincter. Perianal pin prick produced contraction of the external sphincter. In myotonic dystrophy a distinctly myotonic contraction was produced in both smooth and striated portions of the anal sphincter. REFERENCES 1. Schuster, M. M., P. Hookman, T. R. Hendrix, and A. I. Mendeloff. 1965. Simultaneous
manometric recording of in ternal and external anal sphincteric refl exes. Bull. Hopkins Ho sp .116 : 79-88. 2. Albrecht, W. 1920. The esophagus in myotonia dystrophia. Arch. Laryngol. Rhinol. 33: 145-153. 3. Hirschfield, R. 1911. Myotonia dystrophia. Zbl. Ges. N eurol. Psychiat. 5: 682-689. 4. D'Antona, L . 1935. Osservazioni Sullo Stato Dell'Apparato Circolatorio e Digerente Nella Distrofia Miotonica. Minerva Med. 26: 833-841.
5. Masucci, E. F., H . D . Carter, and S. Katz. 1962. Involuntary muscle involvement (cardiac and esophageal) in myotonia dystrophica. Med. Ann. D. C. 31: 630-637. 6. Siegel, C. 1., J. C. H arvey, and T. R. H endrix. 1962. The swallowing disorder in myotonia dystrophica. Clin. Res. 10: 193. (Abstr.) 7. Sherbourne, D . H., and H. Donner. 1965. Myotonic dystrophy. Radiological investigation of the pharynx, esophagus, and gall bladder. Amer. J. Roentgen. In press. 8. Kaufman, K. K ., and E. W. H eckert. 1954.
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Dystrophia myotonica with associated spruelike symptoms. Amer. J. Med. 16: 614-616. 9. Warring, J. J., A. Ravin, and C. E. Walker. 1940. Studies in myotonia dystrophica: Clinical features and treatment. Arch. Intern. Med. (Chicago) 65: 763-799. 10. Harvey, J. C., D. H. Sherbourne, and C. I. Siegel. 1965. Smooth muscle involvement in myotonic dystrophy. Amer. J. Med. 39: 81-90. 11. Schuster, M. M., T . R. Hendrix, and A. I.
Vol. 49, No. 6
Mendeloff. 1963. The internal anal sphincter response: Manometric studies of its normal physiology, neural pathways and alterations in bowel disorders. J. Clin. Invest. 42: 196207. 12. Schuster, M. M., P. Hookman, T. R. Hendrix, and A. I. Mendeloff. 1964. Selective impairment of anal sphincters in collagen vascular disease. Presented at meeting of the American Gastroenterological Association, Dallas, Texas, April 25, 1964.
GASTROENTEROLOGY
Copyright
© 1965 by The Williams & Wilkins Co.
ANAL SPHINCTER ABNORMALITIES CHARACTERISTIC OF MYOTONIC DYSTROPHY MARVIN M. ScHUSTER, M.D., DoNALD
E.
Tow, M.D., AND DoNALD
H.
SHERBOURNE, M.B.
Department of Medicine, Baltimore City Hospitals, and The Johns Hopkins University School of Medicine, Baltimore, Maryland
Myotonic dystrophy is a familial disorder of unknown etiology characterized by fron.tal baldness, cataracts, testicular atrophy · and myotonia of skeletal muscle with progressive wasting and weakness. Myotonia may be demonstrated following voluntary contraction with inability to relax the grip after a strong handshake, or mechanically by percussion of the muscles of the thenar eminence. Smooth muscle involvement is less well appreciated in this disorder. In order to assess the effect of myotonic dystrophy upon the smooth and striated muscles of the anal sphincter, separate pressure recordings were simultaneously obtained from the internal anal sphincter, which is composed of smooth muscle, and the external anal sphincter, which is composed of striated muscle. Materials and Methods Two groups of subjects were studied. The first group consisted of 25 normal subjects without gastrointestinal complaints or disease referable to the colon. These were volunteers who either had no known disease, or whose disease, such as pneumonia, was restricted to an organ system other than gastrointestinal. In addition, seven patients with the established diagnosis of myotonic dystrophy were studied from the Received March 5, 1965. Accepted July 9, 1965. Address requests for reprints to: Dr. Marvin M. Schuster, Baltimore City Hospitals, 4940 Eastern Avenue, Baltimore, Maryland 21224. This investigation was supported by Research Grant AM 06352-02 from the National Institute of Arthritis and Metabolic Diseases, and 5 MO 1 FR-35 from the General Clinical Research Center, United States Public Health Service. The authors are grateful to Dr. John C. Harvey for permission to study his patients. 641
Adult Muscle Clinic of The Johns Hopkins Hospital. There were six males, one female. Five of the patients were white, two Negro. Ages ranged from 25 to 66 years, with an average of 45. All had advanced myotonic dystrophy with moderately severe muscle wasting. None was receiving medication. Bowel habits were normal in all but two of the patients, who had moderate constipation. Pressures were recorded separately from the rectum, the internal anal sphincter and the external anal sphincter by a technique previously described.' No premedication or bowel preparation was employed. Recordings were made: (a) during rest, (b) during transient distension of the rectal balloon by 50 cc of air, (c) during maximal voluntary contraction of the anal sphincter, and (d) with balloon distension superimposed upon sustained maximal voluntary contraction. In addition, studies were performed during cutaneous stimulation by perianal pin scratch. The pressure-sensing device consisted of a hollow steel cylinder (fig. lA) around which a double balloon (fig. lB) was tied, creating two separate compartments. Sixteen-gauge needles were soldered to the inner surface of the cylinder and brought to the outer surface, one opening into each balloon compartment. With the subject lying in the left lateral position the metal cylinder with both balloons deflated was inserted into the anal canal in such a manner that, when each balloon was distended with 15 cc of air, the internal balloon was surrounded by the internal sphincter and the external balloon by the subcutaneous bundle of the external sphincter (fig. 2). A Miller Abbott balloon of 50-cc capacity was inserted through _the hollow bore of the metal tube to a depth of 10 em in the rectum. The balloons were connected via polyethylene tubing to pressure transducers (Sanborn model no. 267 B). Tracings were recorded on three channels of a direct writing recorder (Sanborn model 934). A pneumographic tracing on the fourth channel monitored respirations and body movements.
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FIG. 1. Pressure sensing device. A, Hollow steel cylinder with two 16-gauge needles soldered to inner core and opening to surface. B, Double balloon tied around cylinder, creatmg two separate compartments. One needle communicates with each compartment. Polyethylene tubing connects needles to pressure transducers. (Reprinted with permission of the editors and publishers, Bull. Hopkins Hosp. 116: 79, 1965.)
Results Resting state. In normal subjects a steady base line was observed in the resting state. In contrast, four out of the seven patients with myotonic dystrophy demonstrated a spontaneous cyclical contraction and relaxation which was recorded from both the internal and external sphincter balloons (fig. 3). This spontaneous activity was episodically present for approximately onehalf of the recording time. Transient distension. In normal subjects, transient distension of the rectal balloon with 50 cc of air produced relaxation of the internal sphincter and contraction of the external sphincter (fig. 4). The average pressure fall in the internal sphincter was 25 mm Hg and the average duration of relaxation was 15 sec. In patients with myotonic dystrophy two patterns of response to rectal distension were noted. In one, a myotonic contraction of high amplitude and
markedly prolonged duration was seen in both the internal and external anal sphincters (fig. 5A). The internal sphincter did not relax, but instead, after a short delay, it underwent a tonic contraction. The external sphincter had an initial, apparently normal contraction; after a brief delay it then had a tonic contraction of high amplitude and prolonged duration. No contraction was seen in the rectum. In the second type of response the internal sphincter relaxed in normal fashion but then contracted tonically as shown by the sustained rise above resting level (fig. 5B). Both patterns of response (fig. 5A, B) were present in four patients. Two patients had only the pattern illustrated in figure 5A, and one patient only the type illustrated in figure 5B. The relaxation averaged 22 mm Hg in amplitude (range, 6 to 40 mm.) and 10 sec in duration (range, 8 to 20 sec). Contraction of the internal sphincter averaged 22 mm Hg in
December 1965
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MYOTONIC DYSTROPHY
amplitude (range, 10 to 45 mm) and 35 sec in duration (range, 10 to 50 sec) . The external sphincter also underwent tonic contraction averaging 18 mm Hg in amplitude and 28 sec in duration (fig. 6A, B). Voluntary contraction. In normal subjects voluntary contraction of the anal sphincter produced a sharp rise in base line in both sphincter balloons (fig. 7A). If the rectal balloon was distended while contraction was maintained, the internal sphincter relaxed in normal fashion, whereas no further contraction appeared in the external sphincter. A similar response was seen in patients with myotonic dystrophy (fig. 7B). Pressure dropped abruptly (without myotonia) to resting level when voluntary sphincter contraction suddenly ceased. Perianal pin scratch. Scratching the perianal skin of normal subjects with a pin produced contraction of the external sphinc-
+I~~~· ~. -ro]. -~- ~
Rectum
::oi t4
+30
..
Int. Sphinct .
+20
I
+10
(.)
0
c.
:z: + 15 E
+10
E + 5
0
Ext. Sphinct.
- 5
-ro 0
20
40
60
80
100
120
140
Time in Seconds
FIG. 3. Spontaneous cyclical contraction in myotonic dystrophy. In this and in subsequent tracings, pressure change in the balloons is recorded on the vertical axis in millimeters of mercury.
''~L.t-A_~~-vv - 10 I---- . -- Rectum
('~rt II"'\~ Int. Sphinct. !
..r. -10 0
.,;.
J
-zo
I
J: -30
-40
Rectal -- -
btdloon
~ :'~ 1
h
Ext. Sphinct.
-5~1l 0
20
40
60
80
Time in Seconds
FIG. 2. Schematic diagram of recording technique. Metal cylinder with attached double balloon lies in anal canal so that, when inflated, the internal sphincter balloon is surrounded by the internal sphincter and the external sphincter balloon by the subcutaneous bundle of the external sphincter. Note overlap of internal sphincter by deeper bundles of external sphincter. Rectal balloon lies in rectum. (Reprinted with permission of the editors and publishers, Bull. Hopkins Hosp. 116 : 79, 1965.)
FIG. 4. Transient rectal distension m normal subject. In this and in subsequent pressure tracings distension of rectum is indicated by arrows over t ime axis. Upgoing arrow indicates inflation, and do wn going arrow, deflation of rectal balloon. Resting pressure in each balloon is assigned a zero value. Pressure increase above resting level is designated as positive and decrease below this level as negative. R ectal distension (arrows ) produced transient relaxation of internal sphincter and contraction of external sphincter. (Reprinted with permission of the editors and publishers, Bull. Hopkins Hosp. 116: 79, 1965.)
ter (fig. 8A). The average amplitude of contraction was 12 mm Hg and the average duration was 5 sec. In patients with myotonic dystrophy a contraction of high amplitude and prolonged duration was elicited (fig. 8B). The amplitude averaged 30 mm Hg and the duration averaged 20 sec (fig. 6).
644
SCHUSTER E1' AL.
Vol. 49, No. 6
+1~1~
Rectum
;~r~-
Rectum
•20
+ 10
..
+'lO~
+20
Int. Sphinct.
~ -+10
~
0
t• 0~
u
-20
!f•25~ ~ + 15 + 10
4
+30 E •20 E • 10
A
-10
+ 20
(.) -10
-I~
Int. Sphinct.
0
j
Ext. Sphinct.
+
Ext. Sphinct.
5 0
1~ 0204060 80 T ime in Seconds
-
5
1l 0
8
20 40 60 Time in Seconds
80
FIG. 5. Two patterns of response found with transient rectal distension in mvotonic
dys~rophy. A, Contraction of high amplitude and prolonged duration is seen in both internal sp~I~cter
and external sphincter. Internal sphincter failed to relax. (Reprinted with perllllSSIOn, Amer. J. Med. 39: 81, 1965). B, Normal relaxation of internal sphincter was followed by myotonic contraction. Myotonic contraction of external sphincter occurred simultaneously wit~ relaxation . of internal sphincter. By the time that myotonic contraction appeared m mternal sphmcter, the pressure in external sphincter had returned to resting level.
Discussion
Abnormalities of the gastrointestinal tract, generally muscular weakness or disordered peristalsis, have previously been demons.t~ated in myotonic dystrophy. Abnormalities of esophageal motility have been described fluoroscopically. 2 -5 More r~cently, studies of the swallowing mechamsm by manometric and cineradiographic techniques have demonstrated weakness of striated muscle of the pharynx and disordered peristalsis of smooth muscle of the esophagus. 6 - 7 Similar findings of dilation and delayed motility have been described in the small bowel. 8 Cardiospasm has also been recorded as well as ptosis and delayed emptying of the stomach and colon.9 However, with the exception of a recent review including the present studies, 10 the authors concluded that there was no evidence for myotonia in the smooth muscle of the gastrointestinal tract. The present investigation demonstrates myotonia of both the smooth and striated muscle of the anal sphincter. The episodic cyclical contractions seen in ~our of th~ seven patients were noted only m myotome dystrophy and were not found in a large number of other conditions
studied. The significance of this finding is not known. Anatomical relationships in the anal sphincter raise the question whether the pressure rise recorded from the internal sphincter balloon represents contraction of the internal sphincter (smooth muscle) or of the deeper bundles of the external sphincter (striated muscle) which surround the internal sphincter (fig. 2). Although the patterns of response seen in figure 5A are not too different in the internal and external sphincters, the response of each sphincter is quite different in figure 5B. Here the internal sphincter relaxed in normal fashion but then contracted tonically, while the external sphincter underwent tonic contraction of such high amplitude that the writing stylus went off the recording paper. The myotonic contraction of the internal sphincter can be seen to be clearly separate from, and independent of, the myotonic contraction of the external sphincter. In fact, the myotonic response did not appear in the internal sphincter until it had disappeared from the external sphincter. It is, therefore, apparent that the myotonic contraction recorded in the internal sphincter balloon cannot be explained as a reflection of con-
December 1965
645
MYOTONIC DYSTROPHY
AMPLITUDE OF RESPONSES RECTAL DISTENSION INTERNAL SPHINCTER I
~I
REL~~~
~J~TION
PERIANAL SCRATCH
EXTERNAL SPHINCTER
EXTERNAL SPHINCTER
CONTRACTION
CONTRACTION
~
~
50
CD
n ·41-""'" u. "'"'""' 10
· M.D.
NORM. M.D.
A
NORMAL
NORM.
NORM.
o.l----.f.NO:-::R~M.-----M.O.--------
DURATION OF RESPONSES RECTAL Dl STENSION INTERNAL SPHINCTER RELAXATION
.---'---1
CONTRACTION
~
EXTERNAL
PERIANAL SCRATCH
SP~ER
EXTERNAL SPHINCTER
CONTRACTION
CONTRACTION
~
50
.---'---1
40
r+8NORMAL
AVERAGE
0
~~MYOTONIC
2
"
~DYSTROPHY
0
~ 30
"'
10
o. NORM . M.D.
M.D.
fJ
Bo~-----=~----~~ NORM. NORM. M.D.
~MO.
Fw. 6. Quantitative comparison of sphincter responses in normals (light bars) and myotonic dystrophy (shaded bars). A, Amplitude of responses. Note that the greatest difference between the two groups lies in the contractile response of the internal sphincter, the smooth muscle (second pair of bars). B, Duration of response. A comparison of a and b demonstrates a greater difference between normals and myotonic dystrophy in duration than in amplitude of response. The most pronounced difference is again seen to be in internal sphincter contraction (second pair of bars) .
traction of the deeper bundles of the external sphincter. It has been previously demonstrated that voluntary effort may alter the response of the striated muscle, the external sphincter, but not affect the response of the smooth muscle, the internal sphincter (fig. 7A) .1 • 11 It is of interest that the response was normal when distension was superimposed upon voluntary contraction in a myotonic patient
(fig. 7B). Another feature demonstrated by figure 7B is severe weakness in the external sphincter in myotonic dystrophy manifested by the sloping drop in pressure in the external sphincter balloon. This finding is compatible with the poor tone and profound weakness of the anal sphincter on digital examination of these patients. Also of importance is the fact that patients were able to relax the sphincter on command
SCHUSTER ET A L.
646
t40l
:~~ ~~f'vv /- ' 1'\\t~ RECTUM +30
•
"'
:;~Lr~rl ./!\
0
"'
~t ::~ ~)~ n (J~ -20
,j
INT. SPHINCT.
\;
E - 4o E -60
••ol ::~
+10
r
j
~\FJ\ -~
I ~-V>II 'l,_·\vc
g. +20
~
+ IO
u
0
::~~~J\. 0 -5
\______
20 40 60 80 TIME I N SECO NDS
100
\.ij
+1 0 +5
I
..~...
20
Ext. Sphinct.
\_
1~ 0
8
Int. Sphinct.
~
E + 15
EXT. SPH I NCT
,A "\
o
A
Vol. 49 , No.6
---40
Time in
60
80
100
Seconds
FIG. 7. Rectal distension superimposed upon voluntary sphincter contraction. A , Normal subjects (black bar indicates duration of voluntary contraction). Internal sphincter relaxed with rectal distension (arrows), despite voluntary effort to maintain contraction (black bar). Rectal distension produced no alteration in external sphincter. (Reprinted with permission of the editors and publishers, Bull. Hopkins Hosp. 116: 79, 1965.) B, Myotonic. dystrophy. No myotonic response is seen when rectum was distended during voluntary contraction of sphincter.
.,o0 L .. .
r--~_J._~-~ Rectum
+I~ l.~--·
_,o r-
~·~o~ 0
§
.r:; 0
E
t3
Int. Sphinct.
Int. Sphinct.
E +40
-~ Ext. Sphinct.
+20 +10
Ext. Sphinct.
0 -1 0
t 0
0
E +30
0
- 5
'
+10
0. +6 0 I +5 0
-10
t+IO~ E + 5
~:~~u~ ~
l? 0
Rectum
20
A Time in Seconds
B
t 0
20 40 60 Time in Seconds
FIG. 8. Perianal pin scratch. A, Normal subj ects. Brief contraction of external sphincter appeared with perianal scratch (arrow). (Reprinted with permission of the editors and publishers, Bull. Hopkins Hosp. 116: 79, 1965.) B, Myotonic dystrophy. External sphincter contraction of high amplitude (50 mm Hg) and prolonged duration (25 sec) was produced by perianal scratch.
(fig. 7B), demonstrating absence of myotonia under conditions of voluntary sphincteric contraction. This finding is consistent with the clinical observation that mechanically induced myotonia (here induced by balloon distension) may be present when voluntary myotonia is not present. 9 The myotonic pattern seen in the ex-
ternal sphincter response to pin scratch (fig. 8B) is analogous to myotonia induced by percussion of hypothenar muscles. The contraction reflected in the internal sphincter balloon is probably due to the deeper bundles of the external sphincter which surround the internal sphincter balloon (fig. 2). External sphincter contraction was ap-
December 1965
647
MYOTONIC DYSTROPHY
parently recorded in the internal sphincter balloon when the external sphincter contracted without a corresponding alteration of tone in the internal sphincter. This phenomenon can best be illustrated in patients with scleroderma in whom the internal sphincter response is absent. 12 In these patients contraction of the external sphincter is recorded in the internal sphincter balloon when the rectum is distended or when the perianal skin is scratched. Amplitude and duration of response were analyzed quantitatively (fig. 6). Approximately five complexes were averaged for each individual. Although (as demonstrated by the height of the bars) there was significant quantitative variation between individuals, the results in a given subject were quite reproducible. In the external sphincter (fig. 6A, pair of columns on the right) there was a uniform slight increase in amplitude of contraction in myotonic dystrophy as compared to the normal, whether stimulation was by perianal scratch or rectal distension. The major difference between the myotonic and the normal group lay in the response of the internal sphincter (second pair of columns on the left). Whereas in the normal subject rectal distension produced only relaxation and no contraction, a strong contraction either replaced or followed relaxation of the internal sphincter in patients with myotonic dystrophy. While the amplitude of internal sphincter contraction did not overlap, the duration of internal sphincter relaxation was similar in the two groups (fig. 6B, pair of columns on the left). However, when the sphincter contraction was compared (last three pairs of bars) the response was of appreciably longer duration in myotonic dystrophy than in normal subjects. Here again, the greatest difference between the two groups lay in the internal sphincter response (second pair of columns). A contraction of prolonged duration was found in myotonic dystrophy, but not in normal subjects. These numerical results were subjected to statistical analysis by means of the t-test. There was no significant difference between the normal and myotonic dystrophy groups in terms of either amplitude or duration of relaxation of the internal
sphincter. By inspection there was a wide difference between the two groups in both amplitude and duration of contractile response of the internal sphincter. The difference in external sphincter contraction between these groups was statistically significant whether stimulated by rectal distension (for amplitude, P < 0.05; for duration , P < 0.01) or by perianal scratch (for amplitude, P < 0.01; for duration, P < 0.05). Summary
Manometric studies of anal sphincteric responses to rectal distension, perianal pin prick and voluntary contraction, were performed in 25 normal subjects and seven patients with myotonic dystrophy. In the normal subjects balloon distension of the rectum produced relaxation of the internal sphincter and contraction of the external sphincter. Perianal pin prick produced contraction of the external sphincter. In myotonic dystrophy a distinctly myotonic contraction was produced in both smooth and striated portions of the anal sphincter. REFERENCES 1. Schuster, M. M., P. Hookman, T. R. Hendrix, and A. I. Mendeloff. 1965. Simultaneous
manometric recording of in ternal and external anal sphincteric refl exes. Bull. Hopkins Ho sp .116 : 79-88. 2. Albrecht, W. 1920. The esophagus in myotonia dystrophia. Arch. Laryngol. Rhinol. 33: 145-153. 3. Hirschfield, R. 1911. Myotonia dystrophia. Zbl. Ges. N eurol. Psychiat. 5: 682-689. 4. D'Antona, L . 1935. Osservazioni Sullo Stato Dell'Apparato Circolatorio e Digerente Nella Distrofia Miotonica. Minerva Med. 26: 833-841.
5. Masucci, E. F., H . D . Carter, and S. Katz. 1962. Involuntary muscle involvement (cardiac and esophageal) in myotonia dystrophica. Med. Ann. D. C. 31: 630-637. 6. Siegel, C. 1., J. C. H arvey, and T. R. H endrix. 1962. The swallowing disorder in myotonia dystrophica. Clin. Res. 10: 193. (Abstr.) 7. Sherbourne, D . H., and H. Donner. 1965. Myotonic dystrophy. Radiological investigation of the pharynx, esophagus, and gall bladder. Amer. J. Roentgen. In press. 8. Kaufman, K. K ., and E. W. H eckert. 1954.
648
SCHUSTER ET AL.
Dystrophia myotonica with associated spruelike symptoms. Amer. J. Med. 16: 614-616. 9. Warring, J. J., A. Ravin, and C. E. Walker. 1940. Studies in myotonia dystrophica: Clinical features and treatment. Arch. Intern. Med. (Chicago) 65: 763-799. 10. Harvey, J. C., D. H. Sherbourne, and C. I. Siegel. 1965. Smooth muscle involvement in myotonic dystrophy. Amer. J. Med. 39: 81-90. 11. Schuster, M. M., T . R. Hendrix, and A. I.
Vol. 49, No. 6
Mendeloff. 1963. The internal anal sphincter response: Manometric studies of its normal physiology, neural pathways and alterations in bowel disorders. J. Clin. Invest. 42: 196207. 12. Schuster, M. M., P. Hookman, T. R. Hendrix, and A. I. Mendeloff. 1964. Selective impairment of anal sphincters in collagen vascular disease. Presented at meeting of the American Gastroenterological Association, Dallas, Texas, April 25, 1964.