Amyloid myopathy …

Georgette Dib MD

Neuromuscular Disorders

Updated 01.30.2026
Released 10.27.2011
Expires For CME 01.30.2029

Amyloid myopathy

Author: Georgette Dib MD

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Editor: Nicholas E Johnson MD MSCI FAAN

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Amyloid myopathy

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Introduction

Overview

Amyloidosis is a rare disease caused by the deposition of an abnormal protein called amyloid in organs and tissues. The most common types include immunoglobulin light chain amyloidosis (AL), formerly known as primary amyloidosis, (AA) amyloidosis-secondary to chronic inflammation, dialysis-related amyloidosis (beta2M type), hereditary amyloidosis such as familial or mutated amyloid transport protein transthyretin (ATTR) amyloidosis and non-TTR (wild type) hereditary amyloidosis, and organ-specific amyloidosis (02). Amyloidosis can include multiple organ systems, and symptoms vary according to tissue involvement. It can lead to neuropathy, myopathy, and cardiac or renal insufficiency. Amyloid myopathy is a rare, commonly overlooked manifestation of amyloidosis, causing proximal limb muscle weakness and elevated creatine kinase serum levels, among others.

Key points

	• Amyloid myopathy is one of the uncommon manifestations of systemic amyloidosis.
	• AL amyloidosis is the most common form of systemic amyloidosis and accounts for about 61% of total amyloid myopathy cases.
	• The symptoms are usually nonspecific, typically including progressive proximal limb weakness, myalgia, macroglossia, muscle atrophy or pseudohypertrophy, and increased CK level.
	• The diagnosis of amyloid myopathy is usually overlooked, and it is often misdiagnosed as inflammatory myopathy, even when a muscle biopsy is available.
	• When suspecting amyloid myopathy, Congo red staining and either an immunohistochemical assay or immunofluorescence study should be performed.
	• Amyloid myopathy should be a consideration in adults with progressive neuromuscular weakness of uncertain cause.
	• Recognition of amyloid myopathy is important because clinical symptoms may respond to treatment.

Historical note and terminology

The first recognized patient with amyloid-associated muscle involvement was reported by Lubarsch in 1929; both vascular and interstitial deposits were seen in skeletal muscle and heart (16). This entity was not well understood back then. However, with the advancement of diagnostic techniques and a better understanding of amyloid disease, amyloid myopathy is now a well-categorized entity. Classification of amyloidosis is based in part on the chemistry of the amyloid fibrils is clinically classified into familial or acquired, and into systemic or localized (10).

Clinical manifestations

Presentation and course

Amyloid myopathy could be either isolated or associated with systemic amyloidosis. Muscle involvement is rare with systemic amyloidosis and is even less common with ATTR (25). It is usually accompanied by peripheral neuropathy. Although amyloid myopathy patients may not initially experience neuropathy symptoms, careful neurologic examination and electrodiagnostic studies reveal subclinical neuropathy, symmetric proximal weakness, muscle stiffness, pseudohypertrophy, particularly involving the calves or shoulder girdle (with AL amyloidosis), or atrophy (with TTR amyloidosis). Bulbar involvement may manifest as dysphagia or hoarseness, resulting from macroglossia or amyloid infiltration of the pharyngeal and esophageal musculature.

According to Accardi and colleagues, patients can be grouped into three different groups according to their presentation (01). The first group comprises patients with muscle pseudohypertrophy nodules in the muscles, and the second group comprises those with muscle atrophy and degeneration, which constitutes the trickiest diagnosis, given the wide differential that should be excluded. The third group comprises a mixed phenotype of the first two groups (01). AL-associated myopathy can also present with jaw claudication due to involvement of the temporal artery and be misdiagnosed as giant cell arteritis, leading to inappropriate treatment with high-dose corticosteroids (25; 31). Dysphagia and hoarseness may also occur either from macroglossia or from the involvement of the esophagus and pharynx.

Amyloid myopathy is frequently misdiagnosed as an inflammatory myopathy, especially polymyositis, because of similarities in clinical, neurophysiological, and muscle biopsy findings. Both can show similar inflammatory infiltrates on muscle biopsy, especially when only the hematoxylin-eosin stain is used. It can also sometimes mimic inclusion body myositis, presenting with finger flexor weakness, muscle atrophy, and dysphagia (15). Spuler and colleagues found that routine use of Congo red-stained sections increased the frequency of a diagnosis of amyloid myopathy almost 10-fold (29). Sosa and colleagues reported a case of AL amyloidosis presenting as asymmetric scapulohumeral myopathy diagnosed by muscle biopsy (28).

According to Pinto and colleagues, the clinical manifestations of amyloid myopathy can be grouped according to the type of protein involved, as shown in the table below (26):

Table 1. Clinical Manifestations of Amyloid Myopathy

Features	AL amyloidosis	ATTR amyloidosis	Isolated amyloid myopathy
Median age of onset (range), years	65.5 (50-78.5)	66 (45-83)	41.5 (25-63)
Median duration of symptoms at diagnosis (range), months	17.5 (2-120)	12.5 (1-420)	60 (8-336)
Pattern of weakness	• Proximal • Proximal and distal	• Proximal • Proximal and distal • Axial	• Proximal • Distal
Rhabdomyolysis	-	-	+
Dysphagia (%)	+(31.2%)	-	-
Abnormal CK (%)	+(33%)	+(37.5%)	+(100%)
Median CK (range), x ULN	0.77 (0.14-9.22)	0.4 (0.24-3.2)	8.4(2.9-27.2)
Length-dependent peripheral neuropathy (%)	+(40.6%)	+(87.5%)	-
Systemic features (%)	+(100%)	+(87.5%)	-
Abbreviations: +, present; -, absent; ATTR amyloidosis, transthyretin (wild-type and hereditary)amyloidosis; ULN, upper limit of normal.

Prognosis and complications

Outcome in amyloidosis is primarily determined by the amyloid type and the extent of organ involvement, with cardiac disease being the dominant prognostic factor across all subtypes. AL amyloidosis generally carries a poorer prognosis than ATTR amyloidosis due to the direct cardiotoxicity of circulating light chains and the rapid progression of organ dysfunction. The severity of cardiac involvement at diagnosis--reflected by biomarkers such as NT-proBNP and cardiac troponins--forms the basis of validated staging systems and strongly predicts survival. Multiorgan involvement, advanced heart failure, and delayed diagnosis are consistently associated with worse outcomes, underscoring the importance of early recognition before irreversible organ damage occurs.

In AL amyloidosis, depth and speed of hematologic response to plasma cell-directed therapy are critical determinants of survival, with achievement of a very good partial or complete response closely linked to cardiac and overall survival. Functional status, frailty, and comorbidities further influence prognosis and treatment eligibility, particularly for intensive approaches such as autologous stem cell transplantation. In ATTR amyloidosis, disease stage at treatment initiation remains central, although outcomes have improved with the advent of TTR stabilizers and gene-silencing therapies, which can slow disease progression and improve quality of life. Across all forms, timely diagnosis and effective disease-modifying therapy remain the most important modifiable predictors of outcome.

	• Stage 1 — 9.8 years
	• Stage 1 — 9.8 years
	• Stage 3 — 5.3 years
	• Stage 4 — 2.3 years

However, with the new treatment options, the 1-year mortality decreased from 74% (diagnosis made between 1998 and 2002) to 39% (diagnosis made between 2013 to 2017) (04).

Clinical vignette

A 71-year-old woman with a history of primary systemic amyloidosis noted worsening fatigue, claudication, and weakness in her legs more than her arms over the past 2 years. Neurologic examination revealed symmetrical proximal limb weakness with preserved tendon reflexes. Examination showed no other abnormalities. EMG study revealed an irritable myopathy, and CK values were borderline elevated. Bone marrow biopsy revealed an IgG kappa monoclonal gammopathy. MRI of the thighs revealed increased T2 signal of subcutaneous fat and tissue between muscle groups, with only minimal signal intensity alteration of muscle. Muscle biopsy revealed characteristic apple-green birefringent amyloid deposits surrounding individual muscle fibers on Congo red-staining. Electron microscopy demonstrated amyloid filaments in close apposition to muscle fibers exhibiting excessive corrugations of the sarcolemmal membrane.

Biological basis

Etiology and pathogenesis

AL amyloidosis is the most common form of systemic amyloidosis and accounts for about 61% to 75% of total amyloid myopathy cases, per the study by Liewluck and Milone (15). Occasionally, systemic amyloidosis-associated myopathy may be due to mutated transthyretin (ATTR) or amyloid A amyloidosis secondary to chronic inflammatory disorders. Isolated amyloid myopathy (without systemic amyloidosis) was recognized only a few years ago. Amyloid fibril formation is facilitated and driven by aggregation-prone segments within the precursor protein. These segments form tight, complementary interfaces with others in the same protein monomer, allowing monomers to stack into β-sheet spines (31). Amyloid myopathy is characterized by amyloid deposits in either the intramuscular blood vessels or connective tissue elements of the skeletal muscle. Contrary to sporadic inclusion body myositis, hereditary inclusion body myopathies, or myofibrillar myopathies, where sarcoplasmic amyloid inclusions are seen, amyloid deposits are extracellular in amyloid myopathy (15). Amyloid denotes a waxy, amorphous, and eosinophilic material. Amyloidosis can involve multiple organs, including the kidneys, heart, skin, joints, peripheral nerve, and skeletal muscle. The most common form of amyloidosis in the United States is termed “light chain amyloidosis,” which results from the deposition of monoclonal antibody light chains. Of the three types of systemic amyloidosis, primary systemic amyloidosis is the type that most often involves skeletal muscle.

	1. Amyloid fibril deposition: Deposition of insoluble amyloid fibrils in muscle tissue, caused by misfolding of thousands of defective, misfolded proteins that accumulate in extracellular spaces. The most common proteins involved in amyloid myopathy are AL, AA, and TTR. Factors that may predispose to protein misfolding with amyloid formation and deposition include missense and nonsense mutations in the precursor proteins, abnormal proteolytic processing, elevated precursor protein concentrations, interactions with extracellular matrix components, oxidative stress, pH fluctuations, and failure of proteostatic mechanisms (07).
	2. Muscle damage and dysfunction: The accumulation of amyloid fibrils in the muscle leads to:
		• Muscle fiber atrophy: The mechanical disruption of muscle fibers, either by the presence of a misfolded protein or through a mass effect, impairs muscle contraction and metabolism, leading to progressive muscle weakness and atrophy.
		• Impaired muscle regeneration due to disruption of normal cellular processes, including muscle regeneration and inhibiting normal tissue repair.
		• Endomysial inflammation from amyloid deposits, inducing local inflammation, exacerbating muscle damage, and leading to fibrosis and stiffness.
		• Interfering with electrical conduction from amyloid accumulating within or on the sarcolemmal membrane and along the muscle fiber.

Congo red-stained sections revealed infiltration of blood vessel walls and endomysium with amyloid protein as well as an unusual pattern of pathologic changes to muscle fibers. Congo red-stained sections of muscle biopsy viewed under fluorescent or polarized optics, and serum or urine protein immunoelectrophoresis, play an important role in the evaluation of myopathy (05). Neurologic manifestations of amyloidosis may precede involvement of other organs by several years; therefore, recognizing amyloid neuropathy and myopathy is essential as we have effective therapies for light chain (AL) and transthyretin (ATTR) neuropathy (19).

Anoctaminopathy-5 and dysferlinopathy were recognized as causes of isolated amyloid myopathy (25; 31). Isolated amyloid myopathy accounts for almost a quarter of patients with amyloid myopathy, predominantly due to anoctaminopathy-5 (15). There are additional reports of isolated amyloid myopathy secondary to dysferlin (DYSF) gene mutations causing limb girdle muscular atrophy.

Diagnostic workup

Early diagnosis is crucial to prevent irreversible damage and improve prognosis, especially given the advancements in treatment options. A diagnostic delay of amyloidosis is common, and in the Mayo Clinic case series, the median time from the first disease manifestations and diagnosis was 23 months (18). Diagnostic tools include:

	• Analysis of serum and urine electrophoresis and immunofixation, and free light chain assays. A monoclonal protein (M-protein) is often found by immunoelectrophoresis of serum and urine, and this should be a routine diagnostic test during the evaluation of myopathy of unknown cause, followed by tissue biopsy, as monoclonal proteins in the blood or urine can be seen in up to 5.2% of adults aged greater than 70 years (08). Clinicians can also use other noninvasive techniques, like organ-specific biomarkers and imaging.
	• CK that can be normal or mildly elevated.
	• Electromyography showing myopathic features. Nerve conduction velocities and prolonged distal latencies make ATTRv highly prone to being misdiagnosed as demyelinating in up to 13% of ATTRv patients. Temporal dispersion could also be found, but no evidence of conduction block was observed in ATTRv patients (21).
	• Imaging includes CT, MRI, technetium-99m methylene diphosphonate, and technetium 99m-pyrophosphate for skeletal amyloidosis. The MR appearance of amyloid myopathy shows minimal muscle changes and a striking abnormality with marked reticulation of the subcutaneous fat (17). Unique findings on the MRI can alert the clinician to the diagnosis of amyloidosis prior to the muscle biopsy (11).
	• Conventional MRI sequences do not appear to be sensitive for the detection of amyloid deposition; however, MRI can be helpful in displaying hypertrophy of adductor magnus and reticular STIR hyperintensity (30).
	• Histological evaluation of appropriate tissue remains the gold standard for diagnosis. In ATTR amyloidosis, however, non-biopsy diagnosis is possible when 99mtechnetium-labeled bisphosphonate scintigraphy is positive for significant cardiac uptake in the presence of a fully negative screen for a monoclonal gammopathy (31; 08). Once amyloid is identified, accurate amyloid typing is essential, and laser microdissection followed by mass spectrometry-based proteomics should be performed.
	• TTR gene sequencing when there is suspicion of TTR amyloidosis. Identification of TTR variants can help differentiate ATTRv from ATTRwt. Because the prevalence of coexisting monoclonal gammopathy of undetermined significance with ATTRv is reported to be as high as 18% to 49%, gene sequencing should still be considered, even if monoclonal gammopathy has already been identified (13).

None of the procedures is diagnostic, and a biopsy is still required to rule out mimickers and to confirm the diagnosis with Congo red stain, especially when isolated amyloid myopathy is considered. Congo red stain stains the extracellular amyloid deposits a salmon pink color and displays apple-green birefringence and dichroism under polarized light. The type of amyloid protein should then be identified to guide therapy. A proteomics technique using liquid chromatography-tandem mass spectrometry allows direct analysis of the proteins present in the micro-dissected amyloid deposits obtained from paraffin-embedded tissue samples. This technique has emerged as the new gold standard for fibril typing (08).

Management

The recognition of amyloid myopathy is important for timely treatment and improving prognosis, especially given the revolution in treatment options. Previously, the mainstay of treatment for AL amyloidosis was prednisone and melphalan, with survival rates of 12 to 18 months. The introduction of stem cell transplantation improved the survival rate to 48 months for up to 77% of patients, with 2.5% mortality from the transplant itself. Those who are eligible are referred after induction treatment. Bortezomib, a proteasome inhibitor, is frequently used in combination regimens as frontline therapy. Trials from the Amyloidosis Program of Calgary demonstrated improved outcomes with bortezomib-containing regimens, marking it as a viable frontline option (14). As of November 2025, the FDA approved daratumumab, an anti-CD38 monoclonal antibody, in combination with VCd (Dara-VCd) for newly diagnosed AL-amyloidosis. This has led to a variety of other mAbs being considered and further investigated, including isatuximab, belantamab mafodotin, anselamimab and NI009, and elotuzumab. Novel agents, including CAEL-101 and birtamimab, which directly target the misfolded amyloid deposits, are also being investigated. Several other clinical trials are ongoing in the field of amyloidosis, including the EMN27 trial (NCT04617925) investigating the use of belantamab mafodotin, which showed a rapid hematologic response in heavily pretreated patients. NXC-201, a CAR T-cell therapy, received FDA Breakthrough Therapy Designation in January 2026 for relapsed or refractory AL amyloidosis based on promising results in reversing organ damage. More recently, enavogliflozin, an SGLT2 inhibitor developed for treating diabetes, is now being investigated in a randomized double blind placebo controlled study (EMPACT).

Hereditary TTR amyloidosis

Advancements have significantly expanded treatment options for TTR amyloidosis. Although historically liver transplantation was a primary therapeutic approach, targeted medications have now become central to managing the condition. These include:

Gene-silencing therapies.

Vutrisiran and eplontersen. These therapies focus on managing hereditary transthyretin amyloidosis with polyneuropathy by inhibiting TTR production (22).

Patisiran. This RNA interference drug targets TTR protein synthesis and has shown effectiveness in treating both cardiac and polyneuropathy manifestations. It also provides therapeutic potential in wild-type forms, albeit with variable efficacy (24).

TTR stabilizers. Tafamidis and diflunisal are used to stabilize the transthyretin protein, preventing amyloid deposits. Although these drugs are primarily tested in ATTR patients, stabilization of amyloid deposits can help protect muscle tissues in patients with amyloid myopathy. Tafamidis has been widely adopted due to its cardioprotective effects (27).

Gene-editing techniques. Emerging CRISPR-based approaches offer potential to directly modify TTR gene expression, presenting a possible future avenue for more permanent disease control (03).

Supportive and adjunct therapies. Management often includes drugs like doxycycline to reduce amyloid load and interventions like SGLT2 inhibitors for comorbid conditions like heart failure. These therapies, although supportive, enhance overall patient quality of life and help mitigate secondary complications (09).

References

01: Accardi F, Papa V, Capozzi AR, et al. A rare case of systemic AL amyloidosis with muscle involvement: a misleading diagnosis. Case Rep Hematol 2018;2018:9840405. PMID 29651353
02: Benson MD, Buxbaum JN, Eisenberg DS. Amyloid nomenclature 2020: update and recommendations by the International Society of Amyloidosis (ISA) nomenclature committee. Amyloid 2020;27(4):217-22. PMID 33100054
03: Bukhari S, Khan SZ, Ghoweba M, Khan B, Bashir Z. Arrhythmias and device therapies in cardiac amyloidosis. J Clin Med 2024;13(5):1300. PMID 38592132
04: Butt EJ, Boyars MC. An unusual case of heart failure: sometimes when you hear hoof beats you should think of zebras. Cureus 2021;13(12):e20801. PMID 35141062
05: Chapin JE, Kornfeld M, Harris A. Amyloid myopathy: characteristic features of a still underdiagnosed disease. Muscle Nerve 2005;31:266-72. PMID 15478123
06: Chawla J. Stepwise approach to myopathy in systemic disease. Front Neurol 2011;2:49. PMID 21886637
07: Chiti F, Dobson CM. Protein misfolding, amyloid formation, and human disease: a summary of progress over the last decade. Annu Rev Biochem 2017;86:27-68. PMID 28498720
08: Chompoopong P, Mauermann ML, Siddiqi H, Peltier A. Amyloid neuropathy: from pathophysiology to treatment in light-chain amyloidosis and hereditary transthyretin amyloidosis. Ann Neurol 2024;96(3):423-40. PMID 38923548
09: Fine NM, Witteles RM. Drug development for transthyretin amyloidosis: time to fix the system? JACC Case Rep 2024;29(15):102414. PMID 39157559
10: Gentile F, Giannoni A, Aimo A, et al. Clinical and prognostic significance of central and obstructive apneas in patients with transthyretin cardiac amyloidosis. Eur J Prev Cardiol 2024;zwae297. PMID 39308231
11: Hull ME, Griffith L, Kuncl RW, Wigley FM. A deceptive case of amyloid myopathy: clinical and magnetic resonance imaging features. Arthritis Rheum 2001;8:1954-8. PMID 11508448
12: Kelly JJ. Neurologic complications of primary systemic amyloidosis. Rev Neurol Dis 2006;3(4):173-81. PMID 17224900
13: Lewis E, McCulloch S, Mahe E, et al. Effect of the presence of t(11;14) for patients with AL amyloidosis treated with bortezomib-containing regimens: experience from the amyloidosis program of Calgary. Clin Lymphoma Myeloma Leuk 2023;23(10):e331-4. PMID 37532664
14: Lewis S, Huang J, Patel N, et al. Myocardial perfusion imaging-derived left ventricular strain: regional abnormalities associated with transthyretin cardiac amyloidosis. Am Heart J Plus 2024;40:100377. PMID 38510504
15: Liewluck T, Milone M. Characterization of isolated amyloid myopathy. Eur J Neurol 2017;24(12):1437-45. PMID 28888072
16: Lubarsch O. Zur Kenntnis ungewohnlicher Amyloidablagerungen. Virchows Arch Pathol Anat Histol 1929;271:867-89.
17: Metzler JP, Fleckenstein JL, White CL III, Haller RG, Frenkel EP, Greenlee RG Jr. MRI evaluation of amyloid myopathy. Skeletal Radiol 1992;21:463-5. PMID 1439899
18: Muchtar E, Buadi FK, Dispenzieri A, Gertz MA. Immunoglobulin light-chain amyloidosis: from basics to new developments in diagnosis, progosis and therapy. Acta Haematol 2016;135(3):172-90. PMID 26771835
19: Namiranian D, Geisler S. Neuromuscular complications of systemic amyloidosis. Am J Med 2022;135 Suppl 1:S13-9. PMID 35104443
20: Nicolau S, Liewluck T, Milone M. Myopathies with finger flexor weakness: not only inclusion-body myositis. Muscle Nerve 2020;62(4):445-54. PMID 32478919
21: Ohashi N, Kodaira M, Morita H, Sekijima Y. Electrophysiological demyelinating features in hereditary ATTR amyloidosis. Amyloid 2019;26(1):15-23. PMID 30688105
22: Olatunji G, Kokori E, Abraham IC, et al. A mini-review of Vutrisiran and eplonteresen in hereditary transthyretin-mediated amyloidosis with polyneuropathy. Medicine (Baltimore) 2024;103(26):e38767. PMID 38941378
23: Parthiban GP, Wilson J, Nesheiwat J. Amyloid myopathy: a cunning masquerader. Cureus 2023;15(5):e39576. PMID 37378146
24: Pilebro B, Wixner J, Anan I. Anti-PEG antibodies associated with reduced therapeutic effect of patisiran in patients with hereditary transthyretin amyloidosis. Amyloid 2024;31(4):342-3. PMID 39126640
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26: Pinto MV, Milone M, Mauermann ML, et al. Transthyretin amyloidosis: putting myopathy on the map. Muscle Nerve 2020;61(1):95-100. PMID 31587306
27: Shibata A, Izumiya Y, Yoshida T, et al. Effect of tafamidis therapy on physical function in patients with wild-type transthyretin cardiac amyloidosis. J Cardiol 2024:S0914-5087(24)00217-X. PMID 39613156
28: Sosa SM, Aksami A, Pinto MV. Asymmetric scapulohumeral myopathy: expanding the spectrum of AL amyloid myopathy. Neurology 2024;102(17 Suppl 1).
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30: Tasca G, Modoni A, Nicoletti T, Monforte M, Cuccaro A, Ricci E. Muscle hypertrophy in amyloid myopathy. Neuromuscul Dis 2019;29(2):150-1. PMID 30704860
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Contributors

All contributors' financial relationships have been reviewed and mitigated to ensure that this and every other article is free from commercial bias.

Author

Georgette Dib MD

Dr. Dib of Cleveland Clinic has no relevant financial relationships to disclose.
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Editor

Nicholas E Johnson MD MSCI FAAN

Dr. Johnson of Virginia Commonwealth University received consulting fees and/or research grants from AMO Pharma, Avidity, Dyne, Novartis, Pepgen, Sanofi Genzyme, Sarepta Therapeutics, Takeda, and Vertex, consulting fees and stock options from Juvena, and honorariums from Biogen Idec and Fulcrum Therapeutics as a drug safety monitoring board member.
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Former Authors

Emma Ciafaloni MD FAAN
Jasvinder Chawla MD MBA
Michael K Hehir MD
Qihua Fan MD

Patient Profile

Age range of presentation: 45 to 65+ years
Sex preponderance: none
Heredity: Heredity may be a factor for familial amyloidosis related disorders
Population groups selectively affected: None selectively affected
Occupation groups selectively affected: none selectively affected

ICD & OMIM codes

ICD-10: Myopathy, unspecified: G72.9

Myopathy in diseases classified elsewhere: G73.7

Other inflammatory and immune myopathies, not elsewhere classified: G72.49

Amyloidosis, unspecified: E85.9

Muscle weakness (generalized): M62.81
ICD-11: Other specified primary disorders of muscles: 8C7Y

Primary disorders of muscles, unspecified: 8C7Z

Amyloidosis, unspecified: 5D00.Z

Other specified disorders of muscles: FB32.Y
OMIM: Amyloidosis, hereditary, transthyretin-related: #105210

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Amyloid myopathy

Associated Disorders

Peripheral neuropathy, autonomic dysfunction
Multiple myeloma
Cardiomyopathy, arrhythmia,
Kidney disease
Carpal tunnel syndrome
- Spinal stenosis
- Tendon rupture
- Gastrointestinal manifestations including diarrhea, constipation, nausea, vomiting
- Central nervous system involvement

Differential Diagnosis

proximal limb muscle weakness without pseudohypertrophy
finger flexor weakness
inflammatory myopathies
drug- and toxin-induced myopathies
infectious myopathies
- endocrine myopathies
- muscular dystrophies
- anterior horn cell disease (progressive muscular atrophy)
- Lambert-Eaton myasthenic syndrome
- familial amyloid polyneuropathy
- pseudohypertrophy
- amyloidosis

Also Relevant

Distal myopathies
Hereditary amyloid polyneuropathy
Inclusion-body myositis
Neuromuscular pathology: overview
Primary systemic amyloidosis: neurologic complications

Clinical Categories

Neuromuscular Disorders

Amyloid myopathy

Cite this article

Introduction

Overview

Key points

Historical note and terminology

Clinical manifestations

Presentation and course

Table 1. Clinical Manifestations of Amyloid Myopathy

Prognosis and complications

Clinical vignette

Biological basis

Etiology and pathogenesis

Epidemiology

Prevention

Differential diagnosis

Confusing conditions

Diagnostic workup

Management

Hereditary TTR amyloidosis

Special considerations

Pregnancy

References

Contributors

Author

Editor

Former Authors

Patient Profile

ICD & OMIM codes

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