chronic focal polymyositis in the adult · uncomplicated polymyositis is an inflammatory disease of...

Journal of Neurology, Neurosurgery, and Psychiatry, 1981, 44, 419-425

Chronic focal polymyositis in the adultN E BHARUCHA AND J A MORGAN-HUGHES

From the Institute of Neurology, Queen Square, London

S U M M A R Y Four patients with chronic focal polymyositis are described. Treatment withsteroids appeared to halt clinical progression. The clinical features in all four cases were so strik-ingly similar as to constitute a syndrome which can be mistaken for muscular dystrophyor spinal muscular atrophy unless investigated fully.

Uncomplicated polymyositis is an inflammatorydisease of muscle of uncertain aetiology, whichtypically presents with symmetrical limb girdleweakness, usually without wasting or reflex change.'However, there have been occasional reports in theliterature describing unusual presentations. Thesehave included predominantly distal rather thanproximal muscle involvement,2-4 a fascioscapulo-humeral distribution of weakness, closely mimickingFSH dystrophy5-7 and weakness and wastinglargely confined to the quadriceps muscles.8 Highlyselective involvement of individual muscles orgroups of muscles, however, is unusual in polymyo-sitis and when present is generally regarded to bemore in favour of a muscular dystrophy. Waltonand Adams9 found only two patients with selectivewasting and weakness in their series of over 40 cases.

This paper describes four adult patients withmorphologically proven chronic polymyositis, whoexhibited highly selective muscle wasting andweakness, which remained largely confined to theforearm flexors, brachio radialis and quadricepsmuscles.

Case histories

Case I (Nat Hosp No A82412)A 56-year-old housewife was first admitted to theNational Hospital in June 1975, with a ten-year history ofslowly progressive weakness of the legs, characterised bydifficulty in climbing or descending stairs, and in gettingout of a low chair. There was no history of dysphagia,muscle or joint pain, or skin rash, and her general healthhad been good. In infancy she had suffered from acutepoliomyelitis and had been left with considerable wasting,weakness and shortening of the left arm. There was nofamily history of neuro-muscular disease and no knownconsanguinity. On examination her gait was normal but

Address for reprint requests: Dr JA Morgan-Hughes, The NationalHospital for Nervous Diseases, Queen Square, London WCIN 3BG.

Accepted 28 February 1981

she was unable to climb stairs without using her armsand when descending stairs her legs would tend to buckleat the knees. She was able to sit up from a supine positionwithout difficulty. The cranial nerves were normal exceptfor minimal weakness of neck flexion. In the upperlimbs there was long standing wasting and weakness andshortening of the left arm, due to old poliomyelitis.Muscle power in the right arm was normal. In the lowerlimbs there was marked wasting and weakness of bothquadriceps muscles (fig 1). The other lower limb muscleswere normal in both bulk and strength. The limb reflexeswere present, but depressed (except in the left arm,where they were absent) and the plantar responseswere flexor. Sensation was normal to all modalities.

Fig 1 Case 1. Showing marked bilateral selective wastingof the quadriceps.

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Fig 2 Case 1. Muscle biopsy(x 100) ofright triceps muscleshowing moderately variablemuscle fibre size, smallcollections of interstitial andperivascular inflammatory cellsand occasional regeneratingmusclefibres.

Her blood pressure was 120/70 mm/Hg. The followinginvestigations were normal; haemoglobin, full bloodcount, ESR, serology, serum electrolytes and blood urea,serum calcium, phosphorous and alkaline phosphataseblood glucose, liver function tests, T4, plasma, cortisol,chest radiograph and ECG. An auto-antibody screen wasnegative. The serum CPK was 128 IU/I (normal 10-43).

Electromyographic sampling of the right biceps, rightvastus medialis and right tibialis anterior musclesshowed profuse fibrillation potentials at rest. The inter-ference pattern was full, but there was an excess of shortduration polyphasic motor unit action potentials oflow amplitude indicating a primary muscle disease.Biopsy of the right triceps muscle showed moderatevariation in muscle fibre size, with small collections ofinflammatory cells, which were mainly interstitial butsometimes perivascular (fig 2). Occasional regeneratingmuscle fibres were also seen.The patient was treated with prednisone 60 mg on

alternate days and after two months her serum CPKhad fallen to 31 IU/I. Because of mild epigastric dis-comfort and the appearance of small subcapsularcataracts the dose of prednisone was reduced and finallystopped in October 1978. During this time, there hadbeen a slight improvement in muscle strength but thesigns were largely unchanged. Following discontinuationof the steroids her leg weakness became more markedand she developed weakness of grip in the right handand difficulty with swallowing solid foods. When seenin February 1979, there was definite wasting and weak-ness of the brachio-radialis muscle on the right (fig 3)and also of the forearm flexor muscles. The weakness ofthe quadriceps muscles had also progressed but the otherlower limb muscles were normally strong. The serumCPK had risen to 174 IU/l but other investigations werenormal. Prednisone, 20 mg on alternate days was recom-menced with considerable improvement in her mild

wVFig 3 Case 1. To show wasting of right brachioradialis.

dysphagia, but no significant change in the limb weakness.The serum CPK fell to 33 IU/l. When last seen inAugust 1979, she was taking 30 mg of prednisone onalternate days and her condition was static.

Case 2 (Nat Hosp No A97403)A 53-year-old man was admitted to the National Hospitalin May 1978, with a six-year history of slowly progressingweakness of the legs and of his grip. He had difficulty in

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rising from a chair and in climbing stairs and whendescending stairs his legs tended to buckle at the knees.He also complained of weakness of grip with difficultyin holding a briefcase or a golf club. There was no historyof muscle pain, dysphagia or skin rash, and the familyhistory was negative. On examination, his gait wasnormal but he was unable to climb stairs without usinghis arms and descended stairs backwards, locking hisknees at each step to prevent buckling. The cranialnerves were normal except for longstanding weaknessof the left frontalis and orbicularis oculi muscles. In theupper limbs there was severe wasting and weakness ofthe brachioradialis muscles and the long finger flexors(fig 4). The other muscles in the arms were of normalbulk and strength. In the legs there was gross wastingand weakness of both quadriceps muscles, with sparingof the other muscle groups (fig 5). The limb reflexes weredepressed and the knee jerks were only obtained withreinforcement. The plantar responses were flexor andsensory examination was normal. General examinationwas also normal with a blood pressure of 140/90 mmHg.The following investigations were normal; haemoglobin,full blood count, ESR, serology, serum electrolytes andblood urea, serum calcium, inorganic phosphorous,and alkaline phosphatase, blood glucose, liver functiontests, T4, chest radiograph and ECG. An auto-antibody

Fig 5 Case 2. Showing gross bilateral and selectivequadriceps wasting.

screen was negative. The serum CPK was 96 IU/I.(normal 10-66).Electromyography showed profuse fibrillation in the

right biceps and brachioradialis muscles, with increasedinsertion activity in the right tibialis anterior. All themuscles sampled showed short duration low amplitudepolyphasic motor unit action potentials indicatingprimary muscle disease. Motor and sensory conductionin the right median, ulnar and sural nerves was normal.A biopsy of the left biceps muscle showed markedvariation in muscle fibre size with a number of hyper-trophied fibres, which showed early splitting. There werelarge collections of inflammatory cells between themuscle fibres and around the blood vessels (fig 6).Some of the fibres showed vacuolar changes. A numberof regenerating fibres were present.The patient was treated with prednisone 80 mg on

alternate days and during the next two months there wassome improvement in muscle strength. The serum CPKfell to 25 lU/l after five weeks of treatment. The steroiddosage was gradually reduced and when last seen inApril 1980, the CPK was 33 lU/l and his condition wasrelatively static. He was taking 30 mg of prednisoneon alternate days.

Case 3 (Nat Hosp No A76641)A 54-year-old man was first admitted to the NationalHospital in May 1974, with a two-year history of weak-ness involving the legs and hands. His legs tended to

Fig 4 Case 2. Showing advanced wasting offorearm buckle at the knees when descending stairs and he hadflexors. difficulty in getting out of a low chair and in climbing

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stairs. His grip had weakened over the same period andhe was unable to carry a briefcase or use a screwdriver.There was no other significant history and his previoushealth had been good. On examination, his gait wasnormal but he was unable to rise from a chair or climbsteps without using his arms. The cranial nerves werenormal. In the upper limbs, the long finger flexors in theforearm were markedly wasted and weak. The musclebulk and strength elsewhere in the upper limbs wasnormal. In the legs there was selective wasting and weak-ness of both quadriceps muscles (fig 7) the other lowerlimb muscles being normal. The limb reflexes werenormal and there were no sensory changes. The followinginvestigations were normal; haemoglobin, full bloodcount, serology, serum electrolytes and blood urea,serum calcium, phosphorous and alkaline phosphatase,blood sugar, liver function tests, T4, chest radiographand EGG. The ESR was 35 mm in the hour and the ANFwas positive in a titre of less than one in ten. The serumCPK was 250 IU/1.

Electromyographic sampling of the right rectusfemoris, the right flexor carpi ulnaris and the rightbiceps showed spontaneous fibrillation potentials withpolyphasic motor unit action potentials, indicatingprimary muscle disease. Motor and sensory conductionvelocities in the right median and ulnar nerves werenormal. Muscle biopsy (fig 8) showed marked variationin muscle fibre size, with large collections of inflammatorycells which were interstitial and perivascular in distribu-tion. A number of muscle fibres showed evidence ofnecrosis with phagocytosis and regenerating fibres werecommon.

Treatment was commenced with prednisone 80 mg onalterate days, and during the next six weeks there wasimprovement in muscle strength. He was by now ableto rise from a chair without using his arms, although hestill had difficulty in climbing and descending stairs.

Fig 6 Case 2. Muscle biopsyt.*;4+ (x 67) showing variable muscle

fibre size, some hypertrophiedfibres and some evidence ofregeneration. Note the largecollections of inflammatory cellsbetween fibres and around bloodvessels.

The serum CPK fell to 9 IU/l. The dose of prednisonewas gradually reduced to 20 mg on alternate days and onthis regime the weakness in his legs became worse.Progression of the disease was not halted by increasingthe dose of prednisone to 60 mg on alternate days andbecause of the development of cushingoid features,azathioprine, 200 mg a day was added to his treatment

Fig 7 Case 3. Bilateral selective quadriceps wasting.

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Chronic focal polymyositis in the adult

Fig 8 Case 3. Muscle biopsy% ~~~~~~~~x100) shows variable fibres size,

~~~~~~~~~~inflammatory infiltrates, musclenecrosis and phagocytosis with

.some evidence of regeneration.

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in April, 1978. The prednisone was gradually withdrawnbut because of further slow progression in his weaknessit was recommenced in October 1979. When last seen inMarch 1980, he was taking azathioprine, 200 mg per daytogether with prednisone, 20 mg daily, and his conditionwas relatively static.

Case 4This 65-year-old patient was first seen at the NationalHospital in July 1972, with a two-year history of pro-gressive weakness of the arms and legs. On examination,he was unable to rise from a chair or step up a steepstep without using his arms. The cranial nerves werenormal, but in the limbs he had selective wasting andweakness, which was confined to the brachio-radialismuscles and the forearm flexor muscles in the armsand the quadriceps muscles in the le s. The limb re-flexes were depressed but present, and sensation wasnormal. The following investigations were normal;haemoglobin, full blood count, ESR, serology, serumelectrolytes and blood urea, serum calcium, phos-phorus and alkaline phosphatase, blood sugar, liverfunction tests, T4, chest radiograph and ECG. Anauto-antibody screen was negative. The serum CPKwas 106 IU/l. Electromyographic sampling of theright triceps and tibialis anterior muscles showed nospontaneous activity, but the motor units were poly-phasic and of brief amplitude, indicating primarymuscle disease. A muscle biopsy showed markedvariation in muscle fibre size with large collections ofinflammatory cells which were mainly interstitial butsometimes perivascular in distribution (fig 7).Regenerating fibres were relatively common.The patient was started on prednisone, 80 mg on

altemate days, and there was considerable initial im- Fig 9 Case 4. To show wasting of right bronchioradialis.

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provement in muscle strength during the next three tosix months. The CPK fell to 50 IU/l. His improvementwas maintained during the next two years, on a main-tenance dose of prednisone (between 17-5 and 20 mgon alternate days), but then the disease began to progress.The prednisone was increased up to 60 mg on alternatedays without further improvement. Both cyclophospha-mide and azathioprine were added, but because of asevere leucopenia these drugs were withdrawn. Whenlast seen in December, 1977, the disease was relativelystatic and his serum CPK was 95 IU/l.

Discussion

These patients were suffering from a very chronicform of inflammatory myopathy. In each case theonset was insidious and the wasting and weaknesswas largely confined to the quadriceps muscles, theforearm flexors and the brachio-radialis. Thelaboratory findings, which included elevated CPKlevels, myopathic potentials with fibrillations (inthree out of the four cases) and collections ofinflammatory cells on muscle biopsy were all com-patible with the diagnosis of chronic polymyositis.All four patients also showed some initial improve-ment on high doses of steroids which was accompan-ied by a gradual reduction in the CPK levels in theblood. Although they were on a low dose of predni-sone the weakness progressed a little. It did notappear to spread to involve other muscles and allfour patients have remained ambulant and onlymoderately disabled over prolonged periods offollow-up.

This group of middle-aged patients with chronic

Fig 10 Case 4. Muscle biopsy( x 80) shows variable fibre size,mainly interstitial inflammatorycells and regenerating fibres.

polymyositis had such a strikingly similar distribu-tion of muscle weakness as to constitute a syndrome.They had no evidence of associated malignancy orcollagen vascular disease and have been followedup for periods ranging from 6-14 years. Clinicallythis picture is most closely resembled by late onsetmuscular dystrophy'0-12 and spinal muscularatrophy. However, none of these patients had afamily history of neuromuscular disease or a historyof cosanguinity. Moreover, the absence of muscularhypertrophy or fasciculation and the preservation ofthe reflexes in the presence of severe wasting andweakness would be much more in favour of aninflammatory myopathy. This was confirmed by thepresence of profuse fibrillation on EMG (in threeout of four cases,) muscle biopsy appearance, theclinical response to steroids and lowering of CPKlevels during treatment with steroids. It is interestingthat throughout prolonged follow-up the diseaseshowed little or no evidence of spread to othermuscles. Although steroids proved ineffective inimproving the strength of severely wasted musclesthey may have prevented the disease from spreadingas evidenced by Case 1 who deteriorated rapidlywhen treatment was discontinued.

References

1 Bohan A, Peter JB, Bowman RL, Pearson CM.A computer-assisted analysis of 153 patients withpolymyositis and dermatomyositis. Medicine (Balti-more) 1977; 56:255-86.

2 Eaton LM. Perspective of neurology in regard to

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polymyositis. A study of 41 cases. Neurology(Minneap) 1954; 4:245-63.

3 Hollinrake K. Polymyositis presenting as distalmuscle weakness. A case report. J Neurol Sci 1969;8:479-84.

4. Van Kasteren BJ. Polymyositis presenting withchronic progressive distal muscular weakness. JNeurol Sci 1979; 41:307-10.

5 Rothstein TL, Carlson CB, Sumi SM. Poly-myositis with facioscapulohumeral distribution.Arch Neurol 1971; 25:313-9.

6 Munsat TL, Piper D, Cancilla P, and Mednick J.Inflammatory myopathy with facioscapulohumeraldistribution. Neurology (Minneap) 1972; 22:335-47.

7 Bates D, Stevens JC, Hudgson P. "Polymyositis"with involvement of facial and distal musculature.One form of the facioscapulohumeral syndrome?

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J Neurol Scis, 1973; 19:105-8.8 Mohr PD, Knowlson TG. Quadriceps myositis: an

appraisal of the diagnostic criteria of quadricepsmyopathy. Postg MedJ 1977; 53 :757-60.

9 Walton JN, Adams RD. Polymyositis. Edinburgh:Livingstone, 1958.

10 Shy GM, McEachern D. The Clinical features andresponse to cortisone of menopausal musculardystrophy. J Neurol Neurosurg Psychiatry 1951;101-7.

11 Adams RD, Denny-Brown D, Pearson CM. Dis-eases ofmuscle. New York; PB Hoeber Inc., 1953.

12 Nevin S. Two cases of muscular degenerationoccurring in late adult life, with a review of the re-corded cases of late progressive muscular dystrophy(late progressive myopathy). Q J Med (New Series)1936; 5:51-68.



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