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Sporadic inclusion body myositis presenting with severe camptocormia
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Case Reports / Journal of Clinical Neuroscience 20 (2013) 1628–1629
Sporadic inclusion body myositis presenting with severe camptocormia Haihan Ma 1, Kathleen M. McEvoy, Margherita Milone ⇑ Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
a r t i c l e
i n f o
Article history: Received 4 June 2013 Accepted 10 June 2013
Keywords: Axial myopathy Bent spine syndrome Camptocormia Inclusion body myositis Paraspinal muscle weakness
a b s t r a c t Sporadic inclusion body myositis (sIBM) is a slowly progressive idiopathic inflammatory myopathy. The characteristic early quadriceps and finger flexor muscle weakness often leads to the diagnosis of sIBM, especially when all canonical pathological features of sIBM are not present on muscle biopsy. Weakness of the paraspinal muscles, resulting in head drop and/or camptocormia, is a rare clinical finding along the course of sIBM, and even more rare as the presenting feature. We describe two patients with sIBM manifesting with camptocormia as the sole clinical manifestation for several years prior to the diagnosis by muscle biopsy. This observation emphasizes the role of sIBM in the etiology of camptocormia and the need to consider this common myopathy as a cause of weakness, despite the lack of classic quadriceps and finger flexor muscle weakness years after the onset of the paraspinal muscle weakness. Ó 2013 Elsevier Ltd. All rights reserved.
1. Introduction Sporadic inclusion body myositis (sIBM) is the most common acquired myopathy over the age of 50 [1]. sIBM is an idiopathic inflammatory myopathy with degenerative features [2]. Protein misfolding and proteosomal dysfunction seem to be responsible for abnormal protein accumulations in the muscle fibers [2]. The pathological hallmarks of sIBM are inflammatory infiltrates invading non-necrotic muscle fibers, rimmed vacuoles, congophilic deposits and/or 15–18 nm tubulofilaments [2,3]. Patients with these pathological findings meet diagnostic criteria for definite sIBM [3]. Early weakness of the quadriceps and finger flexor muscles is a classic feature of sIBM and a clinical diagnostic criterion for sIBM [3]. Paraspinal muscle weakness as a manifestation of sIBM is infrequent and to our knowledge only three sIBM patients presenting with such a phenotype have been reported [4–6]. We report two patients with pathological features of sIBM who manifested with camptocormia for many years prior to the diagnosis.
2. Case histories
deposits, and a few cytochrome c oxidase-negative fibers, consistent with the diagnosis of sIBM (Fig. 1A–C). MRI of the cervical spine showed no structural abnormalities. 2.2. Patient 2 A 66-year-old man had 7 year history of progressive difficulty maintaining the erect posture and developed a stooped posture. Only recently he developed leg fatigue. His examination showed camptocormia and paraspinal muscle atrophy; he had to push his hands against his thighs to stand. He had mild proximal lower extremity weakness as suggested by his difficulty climbing a 30 cm step, but finger flexor and quadriceps strength was normal. Also, he was able to extend his spine while lying. CK, thyroid-stimulating hormone and inflammatory markers were normal or negative. EMG/nerve conduction study showed myopathic changes with fibrillation potentials in paraspinal muscles and trapezius and a mild sensorimotor peripheral neuropathy. Biopsy of the trapezius revealed few necrotic fibers, fibers with rimmed vacuoles, few endomysial collections of mononuclear inflammatory cells invading non-necrotic muscle fibers and intracellular congophilic deposits (Fig. 1D–F).
2.1. Patient 1 A 78-year-old woman had progressive difficulty maintaining the erect posture for the past 18 years. Only 5–6 years ago she developed dysphagia, followed by left leg and bilateral hand weakness. Her examination revealed moderate to severe weakness and atrophy of the paraspinal muscles resulting in camptocormia that compromised her ability to stand and ambulate, mild bifacial weakness, and generalized limb weakness more severely affecting the finger flexors. Her spine could be extended in the supine position. Creatine kinase (CK) level was 243 U/L (normal level less than 176). Electromyography (EMG)/nerve conduction study showed mixed myopathic and neurogenic motor unit potentials with fibrillation potentials and a mild sensorimotor peripheral neuropathy. Muscle biopsy of the biceps brachii revealed scattered necrotic fibers, a mononuclear inflammatory exudate invading non-necrotic muscle fibers, several fibers with rimmed vacuoles and congophilic ⇑ Corresponding author. Tel.: +1 507 538 1037; fax: +1 507 284 4074. E-mail address: [email protected] (M. Milone) Permanent address: Department of Neurology, The 153rd Hospital of the People’s Liberation Army, Zhengzhou, Henan, China 1
3. Discussion We describe two patients with sIBM who presented with camptocormia due to paraspinal muscle weakness. This preceded the limb and bulbar weakness by more than 10 years in Patient 1; quadriceps, finger flexor and other distal muscles, classically involved in sIBM, were spared 7 years after the onset of camptocormia in Patient 2. Despite the unusual clinical manifestation, their muscle biopsies showed findings consistent with sIBM [3]. Several studies have underlined the early involvement of finger flexors, knee extensors and ankle dorsiflexors in sIBM [1,7–9]. These clinical features allow the diagnosis of probable sIBM when canonical pathological findings, such as intracellular amyloid or tubulofilaments, are absent [3]. Most sIBM patients fall under the category of probable sIBM because of sampling errors or because the classic pathological features may be late findings [10]. Paraspinal muscle weakness is uncommon in sIBM. In large cohorts of sIBM patients, no patient had paraspinal muscle weakness [9,11]. Occasionally, neck muscle weakness affecting flexors more than extensors and less severe than limb weakness has been observed
Case Reports / Journal of Clinical Neuroscience 20 (2013) 1628–1629
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Fig. 1. Muscle biopsy of Patient 1 (A–C) and Patient 2 (D–F) showing autoaggressive mononuclear inflammation, rimmed vacuoles (A, B, D, E; hematoxylin and eosin) and congophilic deposits within vacuolated fibers (C, F; Congo red viewed under rhodamine optics). Scale bar is 50 l.
in the disease course [7]. To our knowledge, only three sIBM patients manifesting paravertebral weakness have been reported, one with dropped head syndrome [5] and two with thoraco-lumbar paraspinal weakness resulting in camptocormia [4,6]. Contrary to the two reported patients with camptocormia, who developed back muscle weakness subacutely [4] or limb weakness shortly after the axial weakness, [6] our patients had insidiously progressive paraspinal muscle weakness for many years (12 years in Patient 1 and 7 years in Patient 2) prior to the development of limb weakness. Our observation of two additional sIBM patients manifesting with camptocormia, and having camptocormia as dominant clinical features for many years, underscores the importance of considering sIBM in the differential diagnosis of paraspinal myopathy. Conflicts of interest/disclosure The authors declare that they have no financial or other conflicts of interest in relation to this research and its publication. Acknowledgments This study was approved by the Mayo Clinic Institutional Review Board. We thank Dr A.G. Engel for the comments and the muscle biopsy photographs. doi:http://dx.doi.org/10.1016/j.jocn.2013.06.004
References 1. Benveniste O, Guiguet M, Freebody J, et al. Long-term observational study of sporadic inclusion body myositis. Brain 2011;134:3176–84. 2. Needham M, Mastaglia FL. Sporadic inclusion body myositis: a continuing puzzle. Neuromuscul Disord 2008;18:6–16. 3. Tawil R, Griggs RC. Inclusion body myositis. Curr Opin Rheumatol 2002;14:653–7. 4. Hund E, Heckl R, Goebel HH, et al. Inclusion body myositis presenting with isolated erector spinae paresis. Neurology 1995;45:993–4. 5. Katz JS, Wolfe GI, Burns DK, et al. Isolated neck extensor myopathy: a common cause of dropped head syndrome. Neurology 1996;46:917–21. 6. Goodman BP, Liewluck T, Crum BA, et al. Camptocormia due to inclusion body myositis. J Clin Neuromuscul Dis 2012;14:78–81. 7. Lotz BP, Engel AG, Nishino H, et al. Inclusion body myositis. Observations in 40 patients. Brain 1989;112:727–47. 8. Dalakas MC. Polymyositis, dermatomyositis and inclusion-body myositis. N Engl J Med 1991;325:1487–98. 9. Amato AA, Gronseth GS, Jackson CE, et al. Inclusion body myositis: clinical and pathological boundaries. Ann Neurol 1996;40:581–6. 10. Benveniste O, Hilton-Jones D. International workshop on inclusion body myositis held at the institute of myology, Paris, on 29 May 2009. Neuromuscul Disord 2010;20:414–21. 11. Dimachkie MM, Barohn RJ. Inclusion body myositis. Curr Neurol Neurosci Rep 2013;13:321.
Case Reports / Journal of Clinical Neuroscience 20 (2013) 1628–1629
Sporadic inclusion body myositis presenting with severe camptocormia Haihan Ma 1, Kathleen M. McEvoy, Margherita Milone ⇑ Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
a r t i c l e
i n f o
Article history: Received 4 June 2013 Accepted 10 June 2013
Keywords: Axial myopathy Bent spine syndrome Camptocormia Inclusion body myositis Paraspinal muscle weakness
a b s t r a c t Sporadic inclusion body myositis (sIBM) is a slowly progressive idiopathic inflammatory myopathy. The characteristic early quadriceps and finger flexor muscle weakness often leads to the diagnosis of sIBM, especially when all canonical pathological features of sIBM are not present on muscle biopsy. Weakness of the paraspinal muscles, resulting in head drop and/or camptocormia, is a rare clinical finding along the course of sIBM, and even more rare as the presenting feature. We describe two patients with sIBM manifesting with camptocormia as the sole clinical manifestation for several years prior to the diagnosis by muscle biopsy. This observation emphasizes the role of sIBM in the etiology of camptocormia and the need to consider this common myopathy as a cause of weakness, despite the lack of classic quadriceps and finger flexor muscle weakness years after the onset of the paraspinal muscle weakness. Ó 2013 Elsevier Ltd. All rights reserved.
1. Introduction Sporadic inclusion body myositis (sIBM) is the most common acquired myopathy over the age of 50 [1]. sIBM is an idiopathic inflammatory myopathy with degenerative features [2]. Protein misfolding and proteosomal dysfunction seem to be responsible for abnormal protein accumulations in the muscle fibers [2]. The pathological hallmarks of sIBM are inflammatory infiltrates invading non-necrotic muscle fibers, rimmed vacuoles, congophilic deposits and/or 15–18 nm tubulofilaments [2,3]. Patients with these pathological findings meet diagnostic criteria for definite sIBM [3]. Early weakness of the quadriceps and finger flexor muscles is a classic feature of sIBM and a clinical diagnostic criterion for sIBM [3]. Paraspinal muscle weakness as a manifestation of sIBM is infrequent and to our knowledge only three sIBM patients presenting with such a phenotype have been reported [4–6]. We report two patients with pathological features of sIBM who manifested with camptocormia for many years prior to the diagnosis.
2. Case histories
deposits, and a few cytochrome c oxidase-negative fibers, consistent with the diagnosis of sIBM (Fig. 1A–C). MRI of the cervical spine showed no structural abnormalities. 2.2. Patient 2 A 66-year-old man had 7 year history of progressive difficulty maintaining the erect posture and developed a stooped posture. Only recently he developed leg fatigue. His examination showed camptocormia and paraspinal muscle atrophy; he had to push his hands against his thighs to stand. He had mild proximal lower extremity weakness as suggested by his difficulty climbing a 30 cm step, but finger flexor and quadriceps strength was normal. Also, he was able to extend his spine while lying. CK, thyroid-stimulating hormone and inflammatory markers were normal or negative. EMG/nerve conduction study showed myopathic changes with fibrillation potentials in paraspinal muscles and trapezius and a mild sensorimotor peripheral neuropathy. Biopsy of the trapezius revealed few necrotic fibers, fibers with rimmed vacuoles, few endomysial collections of mononuclear inflammatory cells invading non-necrotic muscle fibers and intracellular congophilic deposits (Fig. 1D–F).
2.1. Patient 1 A 78-year-old woman had progressive difficulty maintaining the erect posture for the past 18 years. Only 5–6 years ago she developed dysphagia, followed by left leg and bilateral hand weakness. Her examination revealed moderate to severe weakness and atrophy of the paraspinal muscles resulting in camptocormia that compromised her ability to stand and ambulate, mild bifacial weakness, and generalized limb weakness more severely affecting the finger flexors. Her spine could be extended in the supine position. Creatine kinase (CK) level was 243 U/L (normal level less than 176). Electromyography (EMG)/nerve conduction study showed mixed myopathic and neurogenic motor unit potentials with fibrillation potentials and a mild sensorimotor peripheral neuropathy. Muscle biopsy of the biceps brachii revealed scattered necrotic fibers, a mononuclear inflammatory exudate invading non-necrotic muscle fibers, several fibers with rimmed vacuoles and congophilic ⇑ Corresponding author. Tel.: +1 507 538 1037; fax: +1 507 284 4074. E-mail address: [email protected] (M. Milone) Permanent address: Department of Neurology, The 153rd Hospital of the People’s Liberation Army, Zhengzhou, Henan, China 1
3. Discussion We describe two patients with sIBM who presented with camptocormia due to paraspinal muscle weakness. This preceded the limb and bulbar weakness by more than 10 years in Patient 1; quadriceps, finger flexor and other distal muscles, classically involved in sIBM, were spared 7 years after the onset of camptocormia in Patient 2. Despite the unusual clinical manifestation, their muscle biopsies showed findings consistent with sIBM [3]. Several studies have underlined the early involvement of finger flexors, knee extensors and ankle dorsiflexors in sIBM [1,7–9]. These clinical features allow the diagnosis of probable sIBM when canonical pathological findings, such as intracellular amyloid or tubulofilaments, are absent [3]. Most sIBM patients fall under the category of probable sIBM because of sampling errors or because the classic pathological features may be late findings [10]. Paraspinal muscle weakness is uncommon in sIBM. In large cohorts of sIBM patients, no patient had paraspinal muscle weakness [9,11]. Occasionally, neck muscle weakness affecting flexors more than extensors and less severe than limb weakness has been observed
Case Reports / Journal of Clinical Neuroscience 20 (2013) 1628–1629
1629
Fig. 1. Muscle biopsy of Patient 1 (A–C) and Patient 2 (D–F) showing autoaggressive mononuclear inflammation, rimmed vacuoles (A, B, D, E; hematoxylin and eosin) and congophilic deposits within vacuolated fibers (C, F; Congo red viewed under rhodamine optics). Scale bar is 50 l.
in the disease course [7]. To our knowledge, only three sIBM patients manifesting paravertebral weakness have been reported, one with dropped head syndrome [5] and two with thoraco-lumbar paraspinal weakness resulting in camptocormia [4,6]. Contrary to the two reported patients with camptocormia, who developed back muscle weakness subacutely [4] or limb weakness shortly after the axial weakness, [6] our patients had insidiously progressive paraspinal muscle weakness for many years (12 years in Patient 1 and 7 years in Patient 2) prior to the development of limb weakness. Our observation of two additional sIBM patients manifesting with camptocormia, and having camptocormia as dominant clinical features for many years, underscores the importance of considering sIBM in the differential diagnosis of paraspinal myopathy. Conflicts of interest/disclosure The authors declare that they have no financial or other conflicts of interest in relation to this research and its publication. Acknowledgments This study was approved by the Mayo Clinic Institutional Review Board. We thank Dr A.G. Engel for the comments and the muscle biopsy photographs. doi:http://dx.doi.org/10.1016/j.jocn.2013.06.004
References 1. Benveniste O, Guiguet M, Freebody J, et al. Long-term observational study of sporadic inclusion body myositis. Brain 2011;134:3176–84. 2. Needham M, Mastaglia FL. Sporadic inclusion body myositis: a continuing puzzle. Neuromuscul Disord 2008;18:6–16. 3. Tawil R, Griggs RC. Inclusion body myositis. Curr Opin Rheumatol 2002;14:653–7. 4. Hund E, Heckl R, Goebel HH, et al. Inclusion body myositis presenting with isolated erector spinae paresis. Neurology 1995;45:993–4. 5. Katz JS, Wolfe GI, Burns DK, et al. Isolated neck extensor myopathy: a common cause of dropped head syndrome. Neurology 1996;46:917–21. 6. Goodman BP, Liewluck T, Crum BA, et al. Camptocormia due to inclusion body myositis. J Clin Neuromuscul Dis 2012;14:78–81. 7. Lotz BP, Engel AG, Nishino H, et al. Inclusion body myositis. Observations in 40 patients. Brain 1989;112:727–47. 8. Dalakas MC. Polymyositis, dermatomyositis and inclusion-body myositis. N Engl J Med 1991;325:1487–98. 9. Amato AA, Gronseth GS, Jackson CE, et al. Inclusion body myositis: clinical and pathological boundaries. Ann Neurol 1996;40:581–6. 10. Benveniste O, Hilton-Jones D. International workshop on inclusion body myositis held at the institute of myology, Paris, on 29 May 2009. Neuromuscul Disord 2010;20:414–21. 11. Dimachkie MM, Barohn RJ. Inclusion body myositis. Curr Neurol Neurosci Rep 2013;13:321.