Aust. N.Z. J. Med. (1977), 7, pp. 420421 CASE REPORT
Primary Hyperparathyroidism Presenting as a Proximal Myopathy R. D. Rollinson" and B. S. Gilligant F r o m the Neurology Department, Alfred Hospital, Melbourne
SUmmary: Primary hyperparathyroidism presenting as a proximal myopathy. R. D. Rollinson and B. S. Gilligan, Aust. N.Z. J. Med., 1977, 7, pp.420421.
A 46-year-old female presented with a three year history of progressive weakness. Asymptomatic apart from proximal m yopath y, multi channel screening and radiological features indicated primary hyperparathyroidism with severe metabolic bone disease. Removal of a parathyroid adenoma led to improvement of muscle strength and regression of bony and metabolic changes. Case History
A 46-year-old housewife presented in April 1975 with a history of gradually increasing weakness, predominantly of proximal muscles, severely limiting her activity. There were no other symptoms. The patient's diet was assessed as adequate, there was no clinical evidence of malabsorption and the patient was exposed daily to sunlight. Physical examination : BP 160/100 mmHg, pulse 80/min. Apart from the multinodular goitre there were no signs other than those related to the neuromuscular system. She had a marked waddling gait with moderate wasting of shoulder and pelvic girdles. There was generalized hypotonia. Hip flexion and extension, abduction of the shoulders and extension of the elbows were markedly weak. All other movements at the hips and shoulders, elbow flexion and movements of the knees were moderately weak. Distally, power was normal. The tendon reflexes were brisk and symmetrical and the plantar responses were flexor. Sensation was normal. Intrestigations
The following investigations were normal : Haematology profile, renal function and electrolytes, liver function tests, creatine kinase and aldolase, glucose tolerance test, plasma cortisols, VMA estimation. Her thyroid function tests showed borderline low T4 pre-operatively but post-operatively were normal. Serum calcium 3.69 mmol/l(2.1-2.6), serum phosphate 0 . 5 mmol/l(0~8-1.3), serum alkaline phosphatase 1644 U/l (20-90). * RACP. Advanced Trainee in Neurology. Research Fellow in cerebrovascular diseases. ?Senior Neurologist. Correspondence: Dr. R. D. Rollinson, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, North Carolina, USA Accepted for publication: 6 April, 1977
Chest X-ray and skeletal survey revealed changes consistent with the metabolic bone disease secondary to primary hyperparathyroidism. Figures 1 and 2 show X-rays of pelvis and upper femora demonstrating bony resorption with a Looser zone in right inferior ramus of pubis. Intravenous pyelogram was normal. Electromyography and nerve conduction were normal. Muscle biopsy of quadriceps muscle showed type I1 B fibre atrophy. Bone biopsy from iliac crest was consistent with osteomalacia. In May 1975 Mr. N. T. Hamilton removed a parathyroid adenoma. She was discharged on the ninth post-operative day on vitamin D 10,000 units mane and calcium supplements. Her discharge serum calcium was 2.1 mmol/l. Her muscle strength gradually improved over a period of months with the early disappearance of the waddling gait. When last reviewed in June 1976 she was asymptomatic with normal serum calcium, phosphate and alkaline phosphatase and radiological evidence of healing of the bony changes. She was on no treatment.
Discussion
The occurrence of myopathy is well documented in primary hyperparathyroidi~m'-~, familial hyperparathyr~idism~and o s t e ~ m a l a c i a . ~ - ~ However as the sole presenting complaint this is exceedingly rare.2 The clinical tetrad of proximal myopathy, bone pains, waddling gait, brisk tendon reflexes is well recognized. Conventional electromyography was normal, not an uncommon finding in this condition. By employing quantitative methods of electromyography more positive results can be obtained.8 Type I1 fibre atrophy is compatible with a metabolic myopathy.' The mechanism of the myopathy is not clear. However it is not related to the serum calcium level5; disorded metabolism of vitamin D seems the most likely m e c h a n i ~ mOsteomalacia .~ is uncommon in primary hyperparathyroidism. The probable mechanism is that excess parathormone leads to diversion of the metabolism of vitamin D to 24-25 dihydroxychole calciferol in the kidney which is inactive, leading to vitamin D deficiency.'O
AUGUST
1977
HYPERPARATHYROIDISM MYOPATHY -
FIGURE Extensive demineralisation with arrows indicating a Looser zone and a subcortical fracture.
The present patient exemplifies the natural history of this metabolic myopathy with slow resolution of weakness with removal of the offending adenoma. Acknowledgement The authors gratefully acknowledge support provided by the Ewen Downie Metabolic Unit of the Alfred Hospital in the management of the metabolic status of this patient. References 1. HLNSON.R. A. (1966): The neurological aspects of hypercalcaemia with special reference to primary hyperparathyroidism, J . 1 0 , Call. Phycns. Land. 1, 41.
42 1
FlGUR 2. Resolution of bone changes after removal of the parathyroid adenoma. 2. MURPHY,T. R., RE MINE,W. H . and BURBANK, M. K. (1960): Report of a case which parathyroid adenoma presented primarily with profound muscular weakness, Mayo Clin. Proc. 35, 629. 3. FRAME,B., HEINZE, E. G. Jr., BLOCK,M. A. and MANSON, G. A. (1968): Myopathy in primary hyperarthyroidism. Observations in three patients, Ann. mrern. Med. 68, 1022. 4. CHOLOD,E. I., HAUST,M. D., HUSION, A. J. and LENISEN. . (1970): Myopathy in primary familial hyperparathyroidism, Amer. J. Med. 48, 700. 5. PRINEAS, J. W., MASON,A. S. and HENSON,R. A. (1965): Myopathy in metabolic bone disease, Brir. med. J . 1, 1034. 6. SCHOTT.G . D. and WILLS,M . R. (1976): Muscle weakness in osteomalacia. Lancer 1, 626. 7. SCHOII, G. D. and WILLS,M. R. (1975): Myopathy in hypercalcaemic osteomalacia presenting in adult life, J. Neurol. Neurosurg. Psychiar. 38,297. 8. IRANI,P. F. (1976): Electromyography in nutritional osteomalacia myooathv. J. Neurol. Neurosurn. Psvchiar. 39. 686. V., and B R O O ~ EM. , A. (1973): Muscle biopsy: a modern 9. D U ~ O W I T Z approach. Saunders, London, pp. 78-80. 10. LUMB,G . A. and STANBURY, M. (1974): Parathyroid function in human Vitamin D deficiency and Vitamin D deficiency in primary hyperparathyroidism, Amer. J . Med. 56, 38.
Primary Hyperparathyroidism Presenting as a Proximal Myopathy R. D. Rollinson" and B. S. Gilligant F r o m the Neurology Department, Alfred Hospital, Melbourne
SUmmary: Primary hyperparathyroidism presenting as a proximal myopathy. R. D. Rollinson and B. S. Gilligan, Aust. N.Z. J. Med., 1977, 7, pp.420421.
A 46-year-old female presented with a three year history of progressive weakness. Asymptomatic apart from proximal m yopath y, multi channel screening and radiological features indicated primary hyperparathyroidism with severe metabolic bone disease. Removal of a parathyroid adenoma led to improvement of muscle strength and regression of bony and metabolic changes. Case History
A 46-year-old housewife presented in April 1975 with a history of gradually increasing weakness, predominantly of proximal muscles, severely limiting her activity. There were no other symptoms. The patient's diet was assessed as adequate, there was no clinical evidence of malabsorption and the patient was exposed daily to sunlight. Physical examination : BP 160/100 mmHg, pulse 80/min. Apart from the multinodular goitre there were no signs other than those related to the neuromuscular system. She had a marked waddling gait with moderate wasting of shoulder and pelvic girdles. There was generalized hypotonia. Hip flexion and extension, abduction of the shoulders and extension of the elbows were markedly weak. All other movements at the hips and shoulders, elbow flexion and movements of the knees were moderately weak. Distally, power was normal. The tendon reflexes were brisk and symmetrical and the plantar responses were flexor. Sensation was normal. Intrestigations
The following investigations were normal : Haematology profile, renal function and electrolytes, liver function tests, creatine kinase and aldolase, glucose tolerance test, plasma cortisols, VMA estimation. Her thyroid function tests showed borderline low T4 pre-operatively but post-operatively were normal. Serum calcium 3.69 mmol/l(2.1-2.6), serum phosphate 0 . 5 mmol/l(0~8-1.3), serum alkaline phosphatase 1644 U/l (20-90). * RACP. Advanced Trainee in Neurology. Research Fellow in cerebrovascular diseases. ?Senior Neurologist. Correspondence: Dr. R. D. Rollinson, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, North Carolina, USA Accepted for publication: 6 April, 1977
Chest X-ray and skeletal survey revealed changes consistent with the metabolic bone disease secondary to primary hyperparathyroidism. Figures 1 and 2 show X-rays of pelvis and upper femora demonstrating bony resorption with a Looser zone in right inferior ramus of pubis. Intravenous pyelogram was normal. Electromyography and nerve conduction were normal. Muscle biopsy of quadriceps muscle showed type I1 B fibre atrophy. Bone biopsy from iliac crest was consistent with osteomalacia. In May 1975 Mr. N. T. Hamilton removed a parathyroid adenoma. She was discharged on the ninth post-operative day on vitamin D 10,000 units mane and calcium supplements. Her discharge serum calcium was 2.1 mmol/l. Her muscle strength gradually improved over a period of months with the early disappearance of the waddling gait. When last reviewed in June 1976 she was asymptomatic with normal serum calcium, phosphate and alkaline phosphatase and radiological evidence of healing of the bony changes. She was on no treatment.
Discussion
The occurrence of myopathy is well documented in primary hyperparathyroidi~m'-~, familial hyperparathyr~idism~and o s t e ~ m a l a c i a . ~ - ~ However as the sole presenting complaint this is exceedingly rare.2 The clinical tetrad of proximal myopathy, bone pains, waddling gait, brisk tendon reflexes is well recognized. Conventional electromyography was normal, not an uncommon finding in this condition. By employing quantitative methods of electromyography more positive results can be obtained.8 Type I1 fibre atrophy is compatible with a metabolic myopathy.' The mechanism of the myopathy is not clear. However it is not related to the serum calcium level5; disorded metabolism of vitamin D seems the most likely m e c h a n i ~ mOsteomalacia .~ is uncommon in primary hyperparathyroidism. The probable mechanism is that excess parathormone leads to diversion of the metabolism of vitamin D to 24-25 dihydroxychole calciferol in the kidney which is inactive, leading to vitamin D deficiency.'O
AUGUST
1977
HYPERPARATHYROIDISM MYOPATHY -
FIGURE Extensive demineralisation with arrows indicating a Looser zone and a subcortical fracture.
The present patient exemplifies the natural history of this metabolic myopathy with slow resolution of weakness with removal of the offending adenoma. Acknowledgement The authors gratefully acknowledge support provided by the Ewen Downie Metabolic Unit of the Alfred Hospital in the management of the metabolic status of this patient. References 1. HLNSON.R. A. (1966): The neurological aspects of hypercalcaemia with special reference to primary hyperparathyroidism, J . 1 0 , Call. Phycns. Land. 1, 41.
42 1
FlGUR 2. Resolution of bone changes after removal of the parathyroid adenoma. 2. MURPHY,T. R., RE MINE,W. H . and BURBANK, M. K. (1960): Report of a case which parathyroid adenoma presented primarily with profound muscular weakness, Mayo Clin. Proc. 35, 629. 3. FRAME,B., HEINZE, E. G. Jr., BLOCK,M. A. and MANSON, G. A. (1968): Myopathy in primary hyperarthyroidism. Observations in three patients, Ann. mrern. Med. 68, 1022. 4. CHOLOD,E. I., HAUST,M. D., HUSION, A. J. and LENISEN. . (1970): Myopathy in primary familial hyperparathyroidism, Amer. J. Med. 48, 700. 5. PRINEAS, J. W., MASON,A. S. and HENSON,R. A. (1965): Myopathy in metabolic bone disease, Brir. med. J . 1, 1034. 6. SCHOTT.G . D. and WILLS,M . R. (1976): Muscle weakness in osteomalacia. Lancer 1, 626. 7. SCHOII, G. D. and WILLS,M. R. (1975): Myopathy in hypercalcaemic osteomalacia presenting in adult life, J. Neurol. Neurosurg. Psychiar. 38,297. 8. IRANI,P. F. (1976): Electromyography in nutritional osteomalacia myooathv. J. Neurol. Neurosurn. Psvchiar. 39. 686. V., and B R O O ~ EM. , A. (1973): Muscle biopsy: a modern 9. D U ~ O W I T Z approach. Saunders, London, pp. 78-80. 10. LUMB,G . A. and STANBURY, M. (1974): Parathyroid function in human Vitamin D deficiency and Vitamin D deficiency in primary hyperparathyroidism, Amer. J . Med. 56, 38.
