Inclusion body myositis

Abstract

The clinical features of inclusion body myositis (IBM) were of minor importance in the design of consensus diagnostic criteria, mainly because of controversial views on the specificity of signs and symptoms, although some authors reported "typical" signs. To re-assess the clinical spectrum of IBM, a single investigator using a standard protocol studied a cohort of 64 patients cross-sectionally. Symptom onset was before the age of 50 years in 20% of cases. Only a few patients (14 %) started with weakness other than that of quadriceps, finger flexor or pharyngeal muscles. The sequence of power loss was erratic, but onset of symptoms with quadriceps weakness predicted an earlier onset of dysphagia in older patients (> or = 56 years) compared with younger ones (< 56 years) (p = 0.02). Despite widespread weakness patients had favourable scores on three commonly used function scales and they kept their employment. Complete wheel-chair dependency was rare (3 %). A dominant characteristic was the anatomical distribution of afflicted muscles: ventral extremity muscle groups were more affected than dorsal muscle groups and girdle muscles were least affected, the latter preserving postural stability. Ankylosis, especially in extension of the fingers,was frequently present. Together with the sparing of intrinsic hand muscles it was helpful in the preservation of many skillful movements. IBM has a unique distribution of muscle weakness. Ankylotic contractures are common. We feel that their joint impact on daily functioning is characteristic for the disease.

Idiopathic inflammatory myopathies – a guide to subtypes, diagnostic approach and treatment

“…Dysphagia occurs in over half of all patients with IBM. 17 The condition follows a slowly progressive course and is unresponsive to immunotherapy. High degrees of disability are seen, especially due to falls and weakness of grip.…”

Diagnostic criteria for idiopathic inflammatory myopathies. Problems of their optimization

“…Спорадический миозит с включениями (inclusion body myositis -IBM) традиционно классифицируется как ИВМ, он имеет ряд особенностей, отличающих его от других вос-палительных миопатий. Важнейшими из них являются се-лективность вовлечения определенных групп мышц, мед-ленно прогрессирующая слабость преимущественно дис-тальных отделов конечностей и плохой ответ на ГК и другие иммуносупрессанты, которые, как правило, эффективны при ПМ/ДМ [34][35][36][37][38][39][40]. Особенностью миозита с включения-ми является асимметрия амиотрофии, более заметная на не-доминирующей стороне глубоких (дистальных) сгибателей пальцев руки (до 82%).…”

C. elegans models of neuromuscular diseases expedite translational research

“…Leading to progressive muscle weakness that descends from proximal to distal limb regions and later affecting respiratory muscles, sporadic inclusion body myositis (IBM) is the most common myopathy in the over 50 age group [127], but also occurs in younger people [128]. An autosomal dominant, familial form of IBM also exists but is rare [129].…”