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JOURNAL OF THE ROYAL SOCIETY OF MEDICINE
Volume 88
August 1995
Testosterone deficiency myopathy Richard W Orrell BSc MRCP1 David F Woodrow MB FRCPath2 Michael C Barrett BSc PhD2 Martin Press MD MRCP3 David J Dick MD FRCP4 R Clive G Rowe MB FRCPath5 Russell J M Lane MD FRCP1
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J R Soc Med 1995;88:454-456
Keywords: myopathy; testosterone deficiency; hypogonadism
Testosterone is recognized to have a positive effect on nitrogen balance and muscle development in hypogonadal menl2, but significantly myopathy secondary to testosterone deficiency has been reported only rarely. We describe a patient who presented with a myopathy associated with testosterone deficiency, and who demonstrated a significant functional and myometric response to treatment.
CASE HISTORY A 75-year-old man presented with progressive weakness of the legs. Two years previously he had first noticed difficulty standing from a bus seat, and then climbing stairs, eventually having to crawl up the stairs. He had not noticed any weakness of the arms. He commented on a burning sensation in his feet at night, but no other sensory disturbance. He had no abnormality of speech or swallowing. Otherwise he was well. He had been treated for hypopituitarism since the age of 64, with cortisone 25 mg in the morning and 12.5 mg at night. He had always had absent body hair, other than on the face and head, and only needed to shave twice per week. He had three children, but had experienced erectile failure since the age of 66. On examination he had features of hypopituitarism, with a smooth shiny skin, absent body hair, and gynaecomastia. He had a waddling gait, and there were features of a
predominantly proximal myopathy, with symmetrical muscle wasting and weakness in the shoulders, arms and legs, but no fasciculation. Hand-held myometry of maximum voluntary contraction, by an experienced operator using standard equipment (Penny and Giles Transducers Ltd)3, and techniques4'5, confirmed and 'Academic Unit of Neuroscience, 2Departments of Histopathology and 3Endocrinology, Charing Cross and Westminster Medical School, Fulham Palace Road, London W6 8RF, 4Department of Neurology, Norfolk and Norwich Hospital, Norwich, Norfolk and 5Department of Pathology, Ipswich Hospital, Ipswich,
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England, UK Correspondence to: Dr Richard W Orrell
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Muscle group Figure 1 Hand-held myometry. post treatment
FJ =Pre treatment; M=3 years
quantified the weakness (Figure 1). Sensation and reflexes were normal in the limbs. Examination of the cranial nerves was normal. His late father and a brother apparently had similar breasts, but normal hair, and his son has little body hair. No endocrine disorder is known in these relatives. INVESTIGATION
Full blood count, ESR, vitamin B12 levels and autoantibodies were normal. Serum creatine kinase was minimally elevated at 360 U/l (normal< 150 U/l). Glucose tolerance was impaired after a 75g load (5.5 mmol/l fasting and 10.8 mmol/l at 2 h, measured in plasma). Serum testosterone was less than 0.6 nmol/l (normal 13-30) with a normal sex hormone binding globulin of 29 nmol/l (normal 20-45). Both LH (1.7U/l), and FSH (0.8U/l), were inappropriately low for the very low testosterone level, indicating secondary hypogonadism. However, pituitary function tests were in other respects normal. In particular, serum prolactin (123 nmol/l) and thyroid function (thyroxine 97 nmol/l, TSH 1.6 mU/l) were normal. Serum cortisol rose normally, from 179 to 718nmol/l in a short Synacthen test. Computerized tomography scan of the head was normal, but for a small (6mm) pituitary gland, at the base of a normal sella. Sensory and motor nerve conduction studies were normal. Electromyograph (EMG) showed no spontaneous activity, but recruitment at low volitional contraction of
JOURNAL OF THE ROYAL SOCIETY OF MEDICINE
short duration polyphasic units up to 2 mV amplitude in vastus medialis. Muscle biopsy of right quadriceps showed evidence of myonecrosis and regeneration, some fibre splitting, and chronic inflammatory cells, chiefly macrophages, infiltrating degenerating fibres. There was also an increase in adipose and fibrous tissue. The internal nuclei count was increased to 10%. Measurement and quantitation of the fibres was performed using standard techniques6. A minimum of 100 fibres of each fibre type was measured and descriptive statistics determined. Atrophy and hypertrophy factors were calculated by standard methods. These are preferred measurements given the skew with multiple peaks of the distribution of muscle fibre diameters7'8. Normal values for quadriceps are: type 1 fibres (mean fibre diameter 61 i, atrophy factor
