OVERUSE SYNDROME: A MUSCLE BIOPSY STUDY

905

OVERUSE SYNDROME: A MUSCLE BIOPSY

TABLE I-BIOPSY AND PATIENT GROUPINGS

STUDY XENIA DENNETT1

HUNTER

JOHN HALL FRY2

Muscle Unit, Royal Children’s Hospital, Parkville, Victoria 3052, Australia;1 and 16 Howard Street, Kew, Victoria 31012 were taken from the affected first dorsal interosseous muscle in 29 women with painful chronic overuse syndrome and from 8 volunteer controls. Structural differences in samples from the women with overuse syndrome included increased type 1 fibres with type grouping, decreased type 2 fibres, type 2 fibre hypertrophy, increased internal nuclear count, mitochondrial changes, and various ultrastructural abnormalities. These changes were related to clinical severity, and point to an organic cause for the syndrome.

Summary

Biopsy specimens

*One patient had both hands equally affected and had bilateral biopsies; tone affected patient had two biopsies 5 mo apart. TABLE II-CONTROL FIBRE TYPE DATA

Introduction

OVERUSE syndrome is a musculoskeletal disorder characterised by pain, tenderness, and often functional loss in muscle groups and ligaments subjected to heavy or unaccustomed use. In severe cases-notably, in musicians and keyboard operators-the consequences may include loss of strength, response, and control,1,2 Two review papers have lately discussed the structural and biochemical changes that arise with exercise of various kinds,34 and in painful musculo-ligamentous overuse there has been much interest in what changes, if any, occur in the affected muscles. Biopsy of affected ligaments might carry a risk of producing new symptoms, but open muscle biopsy can be performed under local anaesthesia without hazard to the patient. For the study reported here we chose open biopsy in preference to percutaneous needle biopsy, which carries a greater risk of damage to the small muscles we wished to sample. While some data are available about the histological changes in other sites of muscular overuse,5-9 we are unaware of any histochemical and ultrastructural studies of the small muscles of the hand. We studied a group of women-predominantly keyboard operators-who had chronic pain and loss of function in various upper-limb muscles, including the first dorsal interosseous muscle (FDIM), as a result of overuse. A biopsy specimen was taken and compared by histochemical, ultrastructural, and morphometric techniques with material from control individuals or the contralateral hand.

Subjects and Methods Selection Criteria The clinical diagnosis of overuse syndrome required a history of hand-use-intense activity, a convincing account of symptoms (ie, an individual rather than general description, with no hint of amplification, distortion, or fabrication), and tenderness in muscle groups and ligaments corresponding to the areas of reported pain. Symptoms had to be of at least 6 months’ duration, and in most subjects had been experienced for more than a year. All patients

Figures are mean (SD); 8 individuals. the level of grade 3 overuse or above, on the 5-interval score described by Fry:! Grade 1.-Pain in one site on causal activity. Grade 2.-Pain in multiple sites on causal activity. Grade 3.-Pain with some other uses of the hand, tender structures demonstrable, may show pain at rest or loss of muscle function. Grade 4.-Pain with all uses of the hand, post-activity pain with minor uses, pain at rest and at night, marked physical signs of tenderness, loss of motor function (loss of response control, weakness. Grade 5.-Loss of capacity for use because of continuous pain; loss of muscle function, particularly weakness; gross were at

physical signs. We present data from six groups- (1) non-affected control; (2) subjects with grade 3 lesions; (3) subjects with grade 4/5 lesions (only 2 had grade 5); (4) subjects with unilateral symptoms in whom biopsy specimens were taken from the non-painful side; (5) specimens from the painful muscle in group 4; and (6) a pooled group of those with affected muscles.

Subjects We studied 8 healthy volunteers (3 keyboard operators, 1 hairdresser, and 4 women who were active at home) and 29 patients. All were women, and the ages ranged from 21 to 42 years (mean 29 ’0 SD7) in controls and from 20 to 59 (mean 39-5 SD 12) for patients. In the volunteers biopsy specimens were taken from the nondominant hand. 22 patients had a single biopsy of an affected FDIM, and 1 of these had a second biopsy from her other affected hand some 5 months later. 7 patients had bilateral biopsies, 6 of

whom had a unilateral lesion so that non-painful, apparently non-affected muscle served as an internal control; these control data were not used in other comparisons. The 7th had biopsy specimens taken from both affected FDIMs. All subjects gave their consent to the procedures after a detailed explanation of their nature and purpose.

Technique of Muscle Biopsy 20. Plata

F, Autran B, Pedroza Martins L, et al. AIDS virus-specific cytotoxic T lymphocytes in lung disorders. Nature 1987, 328: 348-51. C, Altman J, Errasti P, et al. Mechanisms of cell-mediated cytotoxicity in mice rejecting xenogeneic human lymphoblastoid cells. Scand J Immunol 1980; 11:

21. Camaud

503-10. 22

Mitsuya H, Weinhold KJ, Furman PA, et al. 3’-azido-3’-deoxythymidine (BW A5097): An anti-viral agent that inhibits the infectivity and cytopathic effect of human T-lymphotropic virus type I II/lymphadenopathy-asaociated virus in vitro Proc Natl Acad Sci USA 1985; 82: 7096-100.

After subcutaneous infiltration with 2% lignocaine and 1:80 000 adrenaline (care being taken to avoid intramuscular infiltration), a 2 cm incision was made directly over the first dorsal interosseous muscle. Once the muscle was exposed, a block (1x1x3 3 mm) was removed for electron microscopy. A second piece of muscle (about 2 x 3 x 10 mm) was taken for histochemistry. The skin was then repaired with 4/0 silk and a bandage was applied with localised pressure for 24 h. Follow-up in both normal and affected individuals was continued for at least 12 months postoperatively.

906 TABLE IV-GROUP WITH BILATERAL BIOPSIES

Fig 1-Cryostat sections from FDIM 43 preincubation.

stained for ATPase after

pH

A, control showing checkerboard staining pattern. B, grade 3 patient showing increased type 1 fibres (black), many enclosed fibres, and internal nuclei (unstained central regions). Both micrographs x 10, reduced by about

*Non-painful, non-clinically affected side; Mann-Whitney U significant differences.

test,

no

half.

Histochemical and Ultrastructural

Techniques

The first portion of each specimen was fixed in 2% glutaraldehyde in cacodylate buffer for electron microscopy; the other was immediately snap-frozen in isopentane precooled in liquid nitrogen. A standardised battery of histochemical and enzymatic stains was performed on each sample including AMPdeaminase, cytochrome oxidase, amylophosphorylase, alkaline phosphatase, NADH-tetrazolium reductase, lactic dehydrogenase, ATPase (post acid preincubation at pH 4-3 and 46), non-specific esterase, and haematoxylin and eosin, Gomori trichrome, sudan black B, periodic-acid/Schiff, and toluidine blue stains. Morphometric studies were done with a Leitz semi-automatic image analyser. The total number of fibres, internal nuclei, and enclosed type 1 fibres were counted in each specimen. One hundred of both type 1 and 2A fibre types were measured for diameter, area, and form function from each specimen (fewer than 100 fibres were present in two) together with all 2B and intermediate fibres. Atrophy and hypertrophy factorslO were based on fibre diameters outside the range of 30-85 and 45-100 pm for type 1 and type 2 fibres, respectively, with significant atrophy and hypertrophy factors being greater than or equal to 60 and 100, respectively. Values for fibre diameters and areas, percentage of enclosed type 1 fibres, internal nuclei, fibre types, and total area of fibres were obtained. The enclosed fibre count percentage is the sum of all the type 1 fibres completely enclosed by other type 1 fibres divided by the total number of type 1 fibres in the sample multiplied by 100.

A mitochondrial score was based on scalloped, motheaten, and fibre changes-these being given values of 1, 2, and 3,

core

respectively. An electron micrographic (EM) score based on ultrastructural abnormalities was derived from the following weighted abnormalities: sawtooth mitchondria, 1; interfibrillary lipofuscin, Z-band streaming, and fibrillary bodies, 2; and paracrystalline inclusion bodies and fingerprint inclusions, 3. These abnormalities were also totalled by simple addition. All data are expressed as mean (SD). The Mann-Whitney U test was used for nonparametric analysis of difference.

Results The biopsy and patient groupings are shown in table I. Table II shows control data for the FDIM, which is a bimodal muscle with type 1 fibres smaller than type 2 fibres (fig 1). Type 2B fibres are few and seem to be lost or converted to "intermediate" or transitional fibres in the affected patients. Because of this, the subsequent type 2 data refer to pooled type 2 fibres unless otherwise stated. Table III shows the data for affected groups and controls. Results of the bilateral biopsies are shown separately in table IV. In addition to the 6 patients affected unilaterally, 1 other was bilaterally affected and had material taken from both sides, making a total of 8 bilateral biopsies in affected

subjects.

TABLE III-AFFECTED GROUPS COMPARED WITH CONTROLS

Mann-Whitney U tests p

<

005; *, p

<

0.01; t; p

<

0-005 &Dag er;

907 TABLE V-ATROPHY AND HYPERTROPHY FACTORS

Significant atrophy factors for type 1 and 2 fibres are;:’ 60 hypertrophy factors for type 1 and 2 fibres area 100.

and

TABLE VI-ULTRASTRUCTURAL ABNORMALITIES IN SPECIMENS

significant i

*(a) vs (d), p

We identified several morphometric differences between the control group and the grade 4/5 group. The scores were not significantly different from control values in the grade 3 group or the bilateral group; there were, however, significant differences between the grade 3 group and the grade 4/5 group. The pooled affected group also showed some differences from controls. Various mitochondrial abnormalities were noted-for example, scalloped fibres were present in 11 / 13 of the grade 3 group, 17/18 of the grade 4/5 group, and 1/8 controls; motheaten fibres were present in 7, 10, and 3, respectively (rare in 1 of the controls); and cores were present in 1,5, and 2, respectively-but the overall mitochondrial scores did not

Fig 2-Cryostat

sections from affected FDIM stained tetrazolium reductase.

0-01.

differ significantly between the groups. Nor did differences emerge for the EM

the combined raised in the mitochondrial/EM The internal nuclei count was grade 4/5 group. greater in the affected individuals than in controls but again not to a statistically significant extent. It did, however, differ significantly between grade 3 and grade 4/5 patients (table III). There seemed to be no difference between sides in the

weighted

score was

though significantly

score,

bilateral group (table IV). The most pronounced differences were observed with enclosed fibre counts, percentage of type 1 fibres, and percentage of type 2 fibres (table III). As a result of changes

A, motheaten and early-core lesions from grade 4 patients, x 25; B and C, scalloped, twisted (asterisk), and ring fibres (arrow) from grade 4 patient, x 25 and x 40; D, several ring fibres adjacent to hypertrophic fibres with central pallor from grade 3 patient, x 40. All micrographs reduced by about

Fig 3-Ultrastructural changes in muscle. A, B, D from grade 3 patients; C from grade 4 patient. A, subsarcolemmal mitochondrial aggregate as part of a scalloped fibre. Note intemalised outer membrane (arrow). B, extrajunctional site. C, abnormal mitochondria with paracrystalline inclusion bodies (arrows) and enlarged electron dense bodies (asterisks) within one fibre. D, fingerprint inclusion body, adjacent to nucleus

half. £

(n).

by

NADH-

<

908

in type 1 and 2 fibre diameters, areas, and percentages (fig 1), the mean total area of fibres in the affected specimens increased from 100% of the control values to 109-1% and even the bilateral affected side showed an increased total area of 1060%. The greatest overall enlargement was shown by the grade 4/5 group. Among other abnormalities noted (fig 2) were ring fibres (present in 4 grade 3 patients and 5 grade 4/5 patients compared with none of the controls), and small collections of perivascular mononuclear inflanunatory cells (4 grade 3 and 5 grade 4/5, 0 controls. Acute changes such as segmental degeneration, myophagia, necrosis, and basophilia were not seen.

In 24 of the 28 (85-7%) patients with known handedness, the dominant hand was the affected or more affected hand. Specifically, in 5 of the 7 patients in the bilaterally sampled group, fibre size was greater in the dominant than in the non-dominant FDIM; both type 1 and type 2 fibres were larger than in the non-dominant FDIM in 6 cases, but the overall mean values did not differ significantly between sides. For atrophy factors no significant differences emerged between control and affected individuals (table v). Type 2 fibre hypertrophy factors were present in 17 of 31 (54-6%) affected patients, the grade 4/5 group being most severely affected. Table VI lists the most interesting EM changes. Two abnormalities were detected only in the affected individuals-namely, paracrystalline inclusion bodies within mitochondria and fingerprint inclusions. The differences in occurrence between control and affected individuals were significant although the weighted EM score per se was not (table IV). AMP-deaminase deficiency was demonstrated in 2 of the 38 women-both were grade 4 affected individuals. All biopsy scars faded almost to invisibility. In the affected individuals, the FDIM either lost its tenderness or became much less tender within eight weeks of biopsy. Discussion The FDIM is

rarely studied so that the baseline data are

RED-CELL-VOLUME DISTRIBUTION CURVES IN DIAGNOSIS OF GLOMERULAR AND NON-GLOMERULAR HAEMATURIA MASAYOSHI SHICHIRI YASUHIDE NISHIO MATSUHIKO SUENAGA SHIGEO TOMURA

KAZUSHIGE HOSODA MITSUO OGURA HIROSHI SAITO TATSUO SHIIGAI

Kidney Centre and Department of Urology, Tokyo Metropolitan Ookubo Hospital, Tokyo; Department of Internal Medicine, Hokushin General Hospital, Nagano; Department of Internal Medicine, Nakano General Hospital, Tokyo; and Department of Internal Medicine, Toride Kyodo Hospital, Ibaraki, Japan The distribution curves of urinary redblood-cell (RBC) size were obtained from automated blood-cell analysis in 146 patients with definite causes of haematuria. In 65 of 67 patients (97%) with haematuria and glomerulonephritis demonstrated by renal biopsy, urinary RBC had an irregular and asymmetrical distribution with RBC size showing a much smaller volume than that of venous RBC. This "glomerular" distribution contrasted with the "non-glomerular" normal distribution when the peak for RBC was at a larger volume than that for peripheral RBC. In 46 of 47 patients with haematuria who had lower urinary tract lesions other than infection, a non-glomerular distribution was obtained; 30 of these cases also showed glomerular distribution, and were classified as "mixed". All 32 patients with urinary tract infection had either a glomerular or mixed distribution, suggesting that they excreted distorted and dysmorphic urinary RBC. After excluding infections, this simple, rapid, reproducible, and non-invasive technique provides reliable information in distinguising glomerular bleeding from other causes of haematuria.

Summary

Introduction HAEMATURIA poses a diagnostic challenge especially in patients with no evidence of renal or systemic disease. Renal biopsy results in cases of idiopathic haematuria may be 2 normal in up

to

22% of adultsl and 44% of children.

very limited. Our study fully supports the fibre size and type

data of Johnson et all’ and Polgar et al 12 who examined the FDIM in 5 young male cadavers. Overuse syndrome is a contentious disorder. In Australia, Brooks13 believes that it is simply normal fatigue to which is added the patient’s psychological reaction. Even in law the status of the disorder is not clear; again Brooks in Cooper vs The Commonwealth14 blamed the patient’s belief system for symptoms of the disorder. We have identified a collection of changes that cannot be accounted for by known psychological mechanisms. Some of these are similar to changes previously described by Bengtsson 15 and Henricksson16 in other tender muscles. It is not possible to conclude whether these changes result directly from the disorder or from other primary factors that the syndrome

produces. We thank Mr Darren Woolley, B Appl Sc, for histochemical investigations and Miss Vicki Apostopoulos, B Appl Sc, for morphometry. REFERENCES

Fry HJH. Overuse syndrome in musicians: prevention and management. Lancet 1986; ii: 728-31. 2. Fry HJH. Overuse syndrome in musicians-100 years ago, an historical review. Med J Aust 1986; 145: 620-25. 1.

3. Editorial. Aching muscles after exercise. Lancet 1987; ii: 1123-24. 4. Howald H. Training-induced morphological and functional changes in skeletal muscles. Int J Sports Med 1982; 3: 1-12. 5. Howard NJ. Peritendinitis crepitans. J Bone Joint Surg 1937; 19: 447-59. 6. Thompson AR, Plewes LW, Shaw EG. Peritendinitis crepitans and simple Med 1951; 8: tenosynovitis: a clinical study of 544 cases in industry. Br Indu J 150-60. 7. Hikada RD, Stavon RS, Hagerman FC, Sherman WM, Costill DL. Muscle fibre necrosis associated with human marathon runners. J Neurol Sci 1983; 59: 185-203. 8. Dalakas MC, Severe JL, Fletcher F, et al. Neuromuscular symptoms in patients with old poliomyelitis: clinical, virological and immunological studies. In: Halstead LS, Weichers DO, eds. Late effects of poliomyelitis. Miami: Symposia Foundation, 1985: 75-89. 9. Larsson L, Ansved T. Effects of long-term physical training and detraining on enzyme histochemical and functional skeletal muscle characteristics in man. Muscle Nerve 1985; 8: 714-22. 10. Dubowitz V, Brooke M. Muscle biopsy: a modem appraoch. London: Saunders, 1973. 11. Johnson MA, Polgar J, Weightman D, Appleton D. Data on the distribution of fibre types in thirty-six human muscles. J Neurol Sci 1973; 18: 111-29. 12. Polgar J, Johnson MA, Weightman D, Appleton D. Data on fibre size in thirty-six human muscles. J Neurol Sci 1973; 19: 307-18. 13. Brooks PM. Regional pain sundrome—the disease of the 80’s. Bull Post/Grad Commmittee Med Univ Sydney 1986; 42: 55-59. 14. Brooks PM. In: Cooper vs The Commonwealth, Melbourne, March 12, 1987, transcript pp 2003-59. 15. Bengtsson A, Henriksson K-G, Larsson J. Muscle biopsy in primary fibromyalgia. Scand J Rheumatol 1986; 15: 1-6. 16. Henriksson K-G, Bengtsson A, Larsson J, et al. Muscle biopsy findings of possible

diagnostic importance in primary fibromyalgia (fibrositis, myofascial syndrome). Lancet 1982; ii: 1395.