A French review has set out to provide an overview of the most emblematic late-onset myopathies (LOMs), those which may appear after the age of 50, and to identify the pitfalls to be avoided and the important steps in the diagnostic approach to these pathologies. Based on an assessment of the literature and medical data on LOMs, the authors note that, overall
- a small number of LOMs, with acquired and genetic forms, the former being more frequent;
- diseases with a late or very late onset (after the age of 60), often presenting atypically and less severely than early forms, with prominent manifestations that may be more subtle;
- axial weakness as a recurrent feature.
In terms of the prevalence of LOMs, the investigators report that :
- among acquired forms, inclusion myositis (IMB) is the most common (also among all pathologies combined), along with adult nemaline myopathy (SLONM);
- in the genetic forms, facioscapulohumeral dystrophy (FSHD), myotonic dystrophy type 2 and oculopharyngeal muscular dystrophy are the most frequently observed;
- more rarely encountered are metabolic diseases (multiple acyl-CoA dehydrogenase deficiency or MADD, McArdle’s disease, chronic progressive external ophthalmoplegia, etc.), congenital myopathies (horn myopathies, etc.), limb-girdle myopathies (LGMD linked to DYSF, ANO5, TTN, etc.) and Becker’s muscular dystrophy.
Diagnosis of these diseases is all the more important as some are treatable, such as MADD or SLONM. The authors advise that IBM and FSHD should be considered as first-line diagnoses, given their frequency.
They also suggest that the diagnostic strategy should include an in-depth study of the medical history, the search for triggers or aggravating factors, and particular attention to symptoms often attributed to age and sarcopenia.
Late-onset myopathies. Salort-Campana, E. & Attarian, S. Curr Opin Neurol 2024.
