FIGURE 1. (a) Hypertrophic scars postbrachioplasty in the upper arms. (b) Right forearm flexor muscle atrophy.

(MAC) sensory nerve action potentials (SNAP). The ulnar SNAP amplitude was mildly reduced, and median and ulnar motor conduction studies were normal. Needle EMG demonstrated evidence for active and chronic denervation in all right median-innervated muscles, most prominent in forearm muscles, and mild chronic denervation in ulnar intrinsic hand muscles. In the left arm, the MAC SNAP was absent. Neuromuscular ultrasound along the course of the right median nerve from wrist to axilla was normal. The clinical and electrophysiologic features in this patient suggest multiple nerve injuries related to brachioplasty, including a significant right partial proximal median neuropathy, mild right ulnar neuropathy, and left MAC neuropathy; the right MAC SNAP was also absent but without related symptoms. A single center reported that 5% (2 of 40 patients) had MAC neuropathy post-brachioplasty. 3 In another report, 1 of 7 patients developed an ulnar neuropathy.8 The MAC nerve, after penetrating the deep fascia proximal to the elbow, is in the deep plane of dissection for standard brachioplasty and is potentially vulnerable to injury.3 Many surgeons attempt to place scars in the intermuscular septum; deep to this area lie the ulnar and median nerves under the brachial fascia where they could be injured if the deep fascia is penetrated.3,9 Significant nerve injury may follow body contouring procedures such as the increasingly popular brachioplasty. Sujata P. Thawani, MD, MPH1 Phyllis Bieri, MD2 Steven Herskovitz, MD2 1

Peripheral Neuropathy Center, The Neurological Institute of New York, Columbia University Medical Center, New York, New York, USA 2 Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, New York, New York, USA 1. Estimate of Bariatric Surgery Numbers. American Society for Metabolic and Bariatric Surgery [online]. Available at: http://asmbs.org/ 2014/03/estimate-of-bariatric-surgery-numbers/. 2. Gusenoff JA, Coon D, Rubin JP. Brachioplasty and concomitant procedures after massive weight loss: a statistical analysis from a prospective registry. Plast Reconstr Surg 2008;122:595–603.

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3. Knoetgen J III, Moran SL. Long-term outcomes and complications associated with brachioplasty: a retrospective review and cadaveric study. Plast Reconstr Surg 2006;117:2219–2223. 4. American Society of Plastic Surgeons. 2012 Cosmetic Plastic Surgery Statistics [online]. Available at: http://www.plasticsurgery.org/Documents/news-resources/statistics/2012-Plastic-Surgery-Statistics/CosmeticProcedure-Trends-2012.pdf. 5. Cannistra C, Valero R, Benelli C, Marmuse JP. Brachioplasty after massive weight loss: a simple algorithm for surgical plane. Aesthet Plast Surg 2007;31:6–9; discussion 10–11. 6. Knotts CD, Kortesis BG, Hunstad JP. Avulsion brachioplasty: technique overview and 5-year experience. Plast Reconstr Surg 2014;133:283–288. 7. Bossert RP, Dreifuss S, Coon D, et al. Liposuction of the arm concurrent with brachioplasty in the massive weight loss patient: is it safe? Plast Reconstr Surg 2013;131:357–365. 8. Wolf AM, Kuhlmann HW. Reconstructive procedures after massive weight loss. Obes Surg 2007;17:355–360. 9. Samra S, Samra F, Liu YJ, Sawh-Martinez R, Persing J. Optimal placement of a brachioplasty scar: a survey evaluation. Ann Plast Surg 2013;71:329–332.

Published online 20 February 2015 in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/mus.24617

--------------------------------------------------------NECROTIZING MYOPATHY CAUSED BY CENTRAL HYPOTHYROIDISM A 62-year-old woman from Sierra Leone presented with an 8-year history of myalgia. The myalgia began in the context of exposure to atorvastatin, which she had tolerated well for 5 years before having muscle symptoms. Despite discontinuation of the statin, she continued to have myalgia, and creatine kinase (CK) levels rose to >2,000 IU/L. Other laboratory testing, including repeated testing of the thyroid-stimulating hormone (TSH) level, was normal. Because of persistent symptoms, she underwent a muscle biopsy, which revealed a necrotizing myopathy without lymphocytic infiltrates. When she was first seen at our center, clinical evaluation revealed low blood pressure, difficult-to-palpate thyroid gland, and absent ankle jerks. There was tenderness of her thighs to palpation. Motor examination revealed normal muscle bulk and possible mild hip flexor weakness, but the examination was limited by pain. MUSCLE & NERVE

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Laboratory testing revealed a CK of 2,927 IU/L (normal values 24–170 IU/L) and aldolase of 11.3 IU/L (normal values 8.1 U/L). Antibody testing for human immunodeficiency virus, human T-lymphotropic virus I/II, and tissue transglutaminase was negative. Myositis autoantibody testing, including testing for anti-HMG-CoA reductase autoantibodies, was negative. Erythrocyte sedimentation rate was 12 mm/h, vitamin D 25-OH level was low at 10.3 ng/ml (normal 30–100 ng/ml), and the antinuclear antibody titer was weakly positive at 1:80. Although her TSH was within normal limits (1.24 mcIU/ml), free T4 was undetectable. An adrenocorticotropic stimulation test suggested adrenal insufficiency, and she had low insulinlike growth factor-1 (IGF-1) levels. This biochemical profile was consistent with panhypopituitarism. A subsequent brain MRI revealed a diminutive pituitary gland, which was flattened along the floor of the sella. This was compatible with partial empty sella syndrome. The patient was treated with thyroid hormone replacement and hydrocortisone. Within a few months of treatment, her longstanding musculoskeletal symptoms had resolved, and CK decreased to 87 IU/L. Musculoskeletal symptoms occur in 30%–80% of patients with hypothyroidism.1,2 Symptoms can range from myalgia and cramps to weakness, elevated muscle enzymes, and abnormal, often necrotizing, findings on muscle biopsy.3 The majority of patients have primary hypothyroidism and the prevalence of secondary or central hypothyroidism is rare, estimated at between 1 and 5 per 100,000.4 Muscle symptoms such as fatigue and myalgia may also occur in patients with adrenal insufficiency. Furthermore, rhabdomyolysis with CK elevation has been reported rarely in cases of acute adrenal insufficiency complicated by hyponatremia.5 Adrenal insufficiency may have contributed to our patient’s symptoms. However, the chronicity and the lack of hyponatremia suggest that her necrotizing myopathy was predominantly the result of profound hypothyroidism. Although this presentation may suggest the possibility of autoimmune, inherited, or toxic myopathy, it is important to consider the possibility of central hypothyroidism in patients with persistent musculoskeletal symptoms even when TSH levels are normal. In the context of a normal TSH, a low T4 is indicative of inadequate response of the pituitary gland and should prompt further testing for secondary hypothyroidism. Clinicians should obtain free T4 testing in this clinical setting, which establishes the diagnosis and leads to effective treatment. Eleni Tiniakou, MD1 Andrew L. Mammen, MD, PhD2 1

Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA National Institute of Musculoskeletal and Arthritis and Skin Diseases, National Institutes of Health, Bethesda, Maryland, USA

2

1. Cakir M, Samanci N, Balci N, Balci MK. Musculoskeletal manifestations in patients with thyroid disease. Clin Endocrinol (Oxf) 2003;59: 162–167. 2. Duyff RF, van den Bosch J, Laman DM, van Loon BJ, Linssen WH. Neuromuscular findings in thyroid dysfunction: a prospective clinical and electrodiagnostic study. J Neurol Neurosurg Psychiatry 2000;68: 750–755. 3. Scott KR, Simmons Z, Boyer PJ. Hypothyroid myopathy with a strikingly elevated serum creatine kinase level. Muscle Nerve 2002;26:141– 144.

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4. Persani L. Clinical review: Central hypothyroidism: pathogenic, diagnostic, and therapeutic challenges. J Clin Endocrinol Metab 2012;97: 3068–3078. 5. Lau SY, Yong TY. Rhabdomyolysis in acute primary adrenal insufficiency complicated by severe hyponatraemia. Intern Med 2012;51:2371–2374.

Published online 21 March 2015 in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/mus.24637

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DIAGNOSTIC USE OF SURFACE EMG IN A PATIENT WITH SPINAL MUSCULAR ATROPHY We recently documented that surface EMG (SEMG) successfully discriminated between neurogenic and myopathic disorders using the newly devised “Clustering Index” (CI) method.1,2 Here, we report a patient with spinal muscular atrophy (SMA) who had long been misdiagnosed with Duchenne muscular dystrophy (DMD), but in whom SEMG led to a correct diagnosis. A 44-year-old man was admitted to our hospital with dyspnea. Developmentally, he could sit but did not acquire ambulation. He was diagnosed with DMD at age 2 years without further genetic confirmation and had received home care without a ventilator. His skeletal muscles, including the tongue were extremely atrophic, and only slight voluntary movements were noticed in finger flexors, trapezius, and gastrocnemius muscles. We doubted the diagnosis of DMD because of failure to acquire ambulation, preserved cardiopulmonary function, normal creatine kinase, and tongue atrophy instead of macroglossia. SMA was thought to be the more likely, although a congenital myopathy was also considered. He refused to undergo even a brief needle EMG examination. Therefore, we attempted an SEMG evaluation to differentiate a neurogenic from a myopathic disorder. SEMG was performed on the trapezius muscle. Five age- and gender-matched controls (39–51 years) were also examined. All subjects gave informed consent, and the study was approved by the local ethics committee. Two Ag-AgCl cup electrodes were placed on the muscle belly 3 cm apart. The bandpass filter was set at 50 to 1,000 Hz. The subject was asked to perform a sustained contraction of the trapezius muscle, and 10 to 20 SEMG epochs of 1-s length from weak to maximal contractions were recorded from each subject. Eleven SEMG epochs from the patient, and 91 epochs from the controls were collected. Upon visual inspection, single MUPs firing up to 27 Hz were identified in the patient during weak contractions (Fig. 1A), which corresponded to a reduced recruitment pattern on needle EMG. In contrast, a complete interference pattern was observed from the weakest contraction in control subjects (Fig. 1B). The CI method1 using a window width of 7.5 ms was also applied to these signals. In the CI versus area plot, the epochs from the patient and the controls were well segregated (Fig. 1C). SEMG showed no MUPs in the tibialis anterior muscle and MUSCLE & NERVE

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