Clinical and Radiological Features of Intramuscular Orbital Amyloidosis: A Case Series and Literature Review

Tong, Jessica; Juniat, Valerie; McKelvie, Penelope; O’Donnell, Brett A; Hardy, Thomas G.; McNab, Alan A.; Selva, Dinesh

doi:10.1097/iop.0000000000002061

Cited by 7 publications

(8 citation statements)

References 41 publications

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“…Ocular manifestations were rare in the Bulgarian cohort (40)(41)(42)(43). Decreased tear secretion was found in the majority of the cases, while amyloid deposition in the vitreous body and the lens, as well as bilateral ptosis were quite rare.…”

Section: Discussionmentioning

confidence: 95%

Seven Years of Selective Genetic Screening Program and Follow-Up of Asymptomatic Carriers With Hereditary Transthyretin Amyloidosis in Bulgaria

Chamova¹,

Господинова

Asenov³

et al. 2022

Front. Neurol.

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Hereditary transthyretin amyloidosis (ATTRv amyloidosis) is a rare, autosomal-dominant (AD) multisystem disorder resulting from the extracellular deposition of amyloid fibrils formed by a destabilized mutant form of transthyretin (TTR), a transport protein predominantly produced by the liver.AimThe aims of the current study are to demonstrate the Bulgarian experience with the screening programs among the high-risk patient population over the last 7 years, to present the results from the therapy with TTR stabilizer in our cohort, as well as to stress on the importance of a follow-up of asymptomatic carriers with TTR pathogenic variants by a multidisciplinary team of specialists.Materials and MethodsIn 2014, a screening program among the high-risk patient population for ATTRv was initiated in Bulgaria. On one hand, it was conducted to identify new patients and families among people with “red flag” clinical features, while on the other hand, the program aimed to identify TTR mutation carriers among the families with already genetically proven diagnoses. Sanger sequencing methodology was used to make fast target testing for mutations in the TTR gene in the suspected individuals. All of the identified carriers underwent subsequent evaluation for neurological, cardiac, gastroenterological, and neuro-ophthalmological involvement. Those considered affected were provided with multidisciplinary treatment and a follow-up.ResultsAs a result of a 7-year selective screening program among the high-risk patient population and relatives of genetically verified affected individuals, 340 carriers of TTR mutations were identified in Bulgaria with the following gene defects: 78.53% with Glu89Gln, 10.29% with Val30Met, 8.24% with Ser77Phe, 2.06% with Gly47Glu, and 0.59% with Ser52Pro. All of these affected displayed a mixed phenotype with variable ages at onset and rate of progression, according to their mutation. From the 150 patients treated with TTR stabilizer, 84 remained stable, while in other 66 patients the treatment was terminated either because of polyneuropathy progression or due to death. A program for a regular follow-up of asymptomatic carriers in the last 3 years enabled us to detect the transition of 39/65 to symptomatic patients and to initiate treatment in a timely manner.ConclusionBulgarian ATTRv patients display a mixed phenotype with some clinical peculiarities for each mutation that should be considered when treating the affected and the follow-up of the asymptomatic carriers of a specific gene defect.

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Section: Discussionmentioning

confidence: 95%

Seven Years of Selective Genetic Screening Program and Follow-Up of Asymptomatic Carriers With Hereditary Transthyretin Amyloidosis in Bulgaria

Chamova¹,

Господинова

Asenov³

et al. 2022

Front. Neurol.

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“…Amyloid deposition typically exhibits either hypointense or isointense signals on T1 sequences and sometimes appears hypointense on T2 sequences (7). Notably, inhomogeneous enhancement on MRI and calci cation on CT emerge as distinct features (4,7,8).…”

Section: Discussionmentioning

confidence: 99%

“…Nonetheless, involvement of the extraocular muscles is an exceedingly rare (1)(2)(3). To date, a mere 35 cases of localized amyloidosis in the extraocular muscles, with or without systemic involvement, have been reported in the literature (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15). The diagnostic process can be intricate due to the resemblance of clinical features to thyroid eye disease (4).…”

Section: Introductionmentioning

confidence: 99%

A Case of Bilateral Amyloidosis Localized to Extraocular Muscles Mimicking Thyroid Eye Disease

Yoshida-Hata,

Mimura,

Aikawa

et al. 2023

Preprint

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Background:Amyloidosis is a rare condition characterized by the abnormal deposition of amyloid proteins in various tissues and organs. While systemic amyloidosis has been well-documented, amyloid deposition in extraocular muscles is an exceptionally rare occurrence, with only 35 reported cases. This case report sheds light on the importance of considering amyloidosis in the differential diagnosis of patients presenting with proptosis and diplopia, which are often associated with thyroid eye disease. Case Presentation: A woman in her twenties sought medical attention due to a complaint of diplopia. Her ocular examination revealed almost normal findings except for exotropia and proptosis. Orbital magnetic resonance imaging displayed fusiform enlargement of nearly all eye muscles, a presentation typically observed in thyroid eye disease. However, despite corticosteroid therapy, her symptoms showed no improvement. Given the unusual lack of response to conventional treatment, and inhomogeneous enhancement of the muscle, an extraocular muscle biopsy was conducted. This biopsy yielded a unique finding—amyloid deposition within the muscle tissue. This discovery was particularly intriguing due to the extreme rarity of amyloidosis affecting extraocular muscles, with fewer than three dozen documented cases worldwide. Conclusion: This unique case underscores the critical need for a comprehensive approach to diagnosing patients with proptosis and diplopia. While these symptoms are commonly attributed to thyroid eye disease, it is essential to consider alternative diagnoses such as amyloidosis, especially when standard treatments fail to yield results. The discovery of amyloid deposition in the extraocular muscles, although exceedingly rare, emphasizes the significance of a thorough differential diagnosis. In conclusion, this case report highlights the importance of vigilance in clinical practice, encouraging ophthalmologists to explore less common diagnostic possibilities when faced with challenging cases. Further research and clinical investigation are warranted to better understand the mechanisms and potential treatments for amyloidosis affecting the extraocular muscles.

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“…Depositions in the extraocular muscle are rare: only 1.3% of orbital amyloidosis occurs in the extraocular muscles [52]. All muscles may be affected and can show fusiform enlargement with tendon sparing or irregular nodularity [53,54]. MR shows T2 hypointense foci and T1 hypointense or isointense foci and contrast enhancement.…”

Section: Amyloidosismentioning

confidence: 99%

“…MR shows T2 hypointense foci and T1 hypointense or isointense foci and contrast enhancement. CT can show calcifications in the extraocular muscles, adjacent hyperostosis and bony irregularity [54,55].…”

Section: Amyloidosismentioning

confidence: 99%

Orbital Muscle Enlargement: What if It’s Not Graves’ Disease?

Lakerveld

Gijp

2022

Curr Radiol Rep

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Purpose of Review To provide the radiologist with tools to recognize findings atypical for Graves’ ophthalmopathy and differentiate between the most important and common alternative causes of extraocular muscle enlargement on CT and MR imaging. Recent findings We introduce five ‘red flags’ representing features that are atypical for Graves’ ophthalmopathy: unilateral disease, atypical pattern of muscle involvement, adjacent structure involvement, restricted diffusion, and absence of pain. Summary About 95% of the cases with extraocular enlargement are due to Graves’ ophthalmopathy, other causes are less well known and recognized. The ‘red flags’ may aid in recognizing and suggesting alternative diagnoses.

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Clinical and Radiological Features of Intramuscular Orbital Amyloidosis: A Case Series and Literature Review

Cited by 7 publications

References 41 publications

Seven Years of Selective Genetic Screening Program and Follow-Up of Asymptomatic Carriers With Hereditary Transthyretin Amyloidosis in Bulgaria

Seven Years of Selective Genetic Screening Program and Follow-Up of Asymptomatic Carriers With Hereditary Transthyretin Amyloidosis in Bulgaria

A Case of Bilateral Amyloidosis Localized to Extraocular Muscles Mimicking Thyroid Eye Disease

Orbital Muscle Enlargement: What if It’s Not Graves’ Disease?

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