Steroid myopathy (SM) was first described in 1932 by Cushing [1]. It can be caused by excessive endogenous or exogenous corticosteroids. Adrenal tumors are associated with excessive endogenous corticosteroid production while excessive exogenous corticosteroid is due to steroid treatment for medical conditions like asthma, chronic obstructive pulmonary disease, and autoimmune diseases such as polymyositis, connective tissue disorders, and rheumatoid arthritis. [2] [3] [4]. On an average, 12% of patients on steroid treatment develop SM [5] with glucocorticoid-induced myopathy being the commonest drug-induced myopathy [6]. Risk factors for the development of SM include the advanced age, patients with cancer, patients with respiratory muscle weakness, debilitation and physical inactivity.

SM can develop either acutely or insidiously. Acute SM is the rapid onset of progressive generalized weakness as well as proximal and distal muscles weakness [7] including respiratory muscle weakness occurring within a week after the onset of treatment with high-dose corticosteroids [8]. It is commonly seen in patients admitted to intensive care who are on mechanical ventilation with neuromuscular blockade. In chronic SM, there is an insidious onset of progressive proximal muscle weakness in the arms and legs. Pelvic girdle muscles are affected more than the arms with sparing of the sphincteric muscles and the muscles innervated by the cranial nerves. Patients may be unable to rise from chairs or climb stairs or raise their arms above their heads to perform activities. With time, myalgias become constant and studies have reported pulmonary symptoms secondary to weakness of the respiratory muscles like the diaphragm [8]. The pattern of SM is identical in iatrogenic SM as well as endogenous SM [5].

• Fatigue

  We ask about general symptoms (anxious mood, depressed mood, fatigue, pain, and stress) regardless of condition. Last updated: May 12, 2019 [patientslikeme.com]

  In addition, patients complain of fatigue, loss of appetite and fever. Polymyalgia rheumatica is often treated with a low-dose of steroids to relieve the muscular pain. Treatment may be needed for two to six years. [livestrong.com]

  Other symptoms of myositis may include Fatigue after walking or standing Tripping or falling Trouble swallowing or breathing Doctors may use a physical exam, lab tests, imaging tests and a muscle biopsy to diagnose myositis. [fpnotebook.com]

  Adrenal insufficiency commonly causes muscle fatigue. The degree of weakness may be difficult to assess but is typically mild. [frontiersin.org]

  Metabolic Myopathies The primary goal in treating metabolic myopathies is to avoid situations that tax the muscles and promote muscle pain and fatigue. [consultantsinneurology.com]

• Difficulty Climbing Stairs

  Her headaches are gone, but she has difficulty climbing stairs and getting up form a chair.Her blood pressure is 120/70mm Hg, pulse 82/min and respiration are 12/min.Physical examination show 4/5 muscle power in her proximal lower extremities bilaterally [forums.studentdoctor.net]

  Proximal muscle weakness is associated with difficulty climbing stairs, arising from a chair, combing hair or lifting objects overhead. On the other hand, distal muscle weakness can lead to difficulty opening or closing jars, foot drop. [frontiersin.org]

• Unable to Stand

  Today for the first time I was unable to stand up on my own. I have lost all strength in my legs. This is called Steroid Myopathy and is a long-term side-effect of high-dose steroids. It is progressive muscle weakness. [mariechantalmarchand.wordpress.com]

• Wheelchair Bound

  She was otherwise wheelchair-bound. [wrshlaw.com]

• Myopathy

  We recommend that muscle derived enzyme levels should not be used to differentiate steroid myopathy from inflammatory myopathies. [ncbi.nlm.nih.gov]

• Quadriceps Muscle Weakness

  muscle weakness and finger flexor muscle weakness Dysphagia Hypothyroid myopathy Affects 30%–80% of patients with hypothyroidism Proximal symmetrical pelvic shoulder girdle weakness Pseudohypertrophy of muscles Peripheral neuropathy Delayed relaxation [clevelandclinicmeded.com]

• Muscular Atrophy

  Palpation revealed symmetric muscular atrophy at the pelvic and shoulder girdles. No signs of effusion or ecchymosis were present. [jaoa.org]

• Asthenia

  Prognosis Poor prognostic indicators include recalcitrant disease, delay in diagnosis, older age, malignancy, fever, asthenia-anorexia, pulmonary interstitial fibrosis, dysphagia and leukocytosis. [aafp.org]

• Meningism

  The second section is devoted to nervous system metastases, addressing in turn, brain, spinal cord, meningeal and cranial and peripheral nerve metastases, describing clinical symptoms, approach to diagnosis and current treatment. [books.google.com]

The workup in SM is focused on differentiating between endogenous hypercortisolism and exogenous glucocorticoid use. Laboratory tests include creatine kinase, lactate dehydrogenase (LDH), and aldose. In acute SM, patients have elevated levels of serum creatine kinase and aldolase [5] [9] with myoglobinuria. On the other hand, in chronic SM the serum levels of creatine kinase are normal but the urine creatinine clearance increases dramatically and can even appear several days prior to the appearance of symptoms of myopathy [2]. Myoglobinuria and rhabdomyolysis are absent in chronic SM.

Electromyography (EMG) and nerve conduction studies (NCS) in acute SM may reveal abnormal spontaneous activity, early recruitment, and small, polyphasic motor units as well as findings suggestive of neuropathy subsequent to high-dose corticosteroid treatment [10] [11].

Muscle biopsy in acute SM shows focal and diffuse necrosis of all types of muscle fibers without the involvement of type II fibers. In chronic SM, the muscle biopsy demonstrates specific atrophy of type IIb muscle fibers, an absence of inflammatory infiltrate, variations in fiber size with centrally placed nuclei, and occasional muscle necrosis [9].

1. Cushing H. The basophil adenoma of the pituitary body and their clinical manifestation. Johns Hopkins Med J. 1932;50:137
2. Askari A, Vignos PJ Jr, Moskowitz RW. Steroid myopathy in connective tissue disease. Am J Med. 1976 Oct;61(4):485-92.
3. Yamaguchi M, Niimi A, Minakuchi M, et al. Corticosteroid-induced myopathy mimicking therapy-resistant asthma. Ann Allergy Asthma Immunol. 2007 Oct;99(4):371-4.
4. Lacomis D, Smith TW, Chad DA. Acute myopathy and neuropathy in status asthmaticus: case report and literature review. Muscle Nerve. 1993 Jan;16(1):84-90.
5. Alshekhlee A, Kaminski HJ, Ruff RL. Neuromuscular manifestations of endocrine disorders. Neurol Clin. 2002;20:35–58.
6. Gupta A, Gupta Y. Glucocorticoid-induced myopathy: pathophysiology, diagnosis, and treatment. Indian J Endocrinol Metab. 2013 Sep-Oct; 17(5): 913-916
7. Van Balkom RH, van Der Heijden HF, van Herwaarden CL, Dekhuijzen PN. Corticosteroid-induced myopathy of the respiratory muscles. Neth J Med. 1994;45:114–22.
8. Dekhuijzen PN, Decramer M. Steroid-induced myopathy and its significance to respiratory disease: a known disease rediscovered. Eur Respir J. 1992 Sep;5(8):997-1003.
9. Pereira RM, Freire de Carvalho J. Glucocorticoid-induced myopathy. Joint Bone Spine. 2011;78:41–4.
10. Ahlbeck K, Fredriksson K, Rooyackers O, et al. Signs of critical illness polyneuropathy and myopathy can be seen early in the ICU course. Acta Anaesthesiol Scand. 2009 Jul; 53(6):717-23.
11. Hanson P, Dive A, Brucher JM, et al. Acute corticosteroid myopathy in intensive care patients. Muscle Nerve. 1997 Nov; 20(11):1371-80