Background Severe weakness of axial muscle leads to dropped head syndrome or camptocormia. The signification of these symptoms has not been studied in inflammatory myopathies (IM).
Objectives To assess the signification of dropped head syndrome and/or camptocormia in patients with IM.
Methods All practitioners of the French Myositis Network and the Club Rhumatisme et Inflammation (>1000 physicians) were invited to report their patients suffering from IM (myopathy with myositis specific autoantibody and/or typical muscle biopsy according to the ENMC criteria) with camptocormia and/or dropped head syndrome. These axial IM cases were included only if no other explanation of axial weakness was found. IM patients without axial involvement (non-axial IM group), were randomly selected from the participative centers, and included as control patients (ratio 1:2). Clinical, serological, muscle pathological features, management and outcomes were studied using a standardized form.
Results Twenty patients (sex ratio 2.6) with axial involvement (camptocormia: 60%, dropped head syndrome: 40%) were included. Compared with the control group, these axial IM-patients were older (64.05±11.64 y. vs. 48.22±18.28. p<0.005) and diagnosis of IM was delayed (16.4±4.5 months vs. 8.5±2.7, p<0.05).
All patient except one had also proximal weakness of the limbs. CK blood level was 2794±870 UI/L, which was similar to the controls (2864±559 UI/L). According to the ENMC classification, non-specific myositis was the most frequent finding on muscle biopsy (n=5/15, 30% vs. n=1/24, 4% in the non-axial group, p<0.05) and dermatomyositis (DM) pattern tended to be less frequent in axial-IM patients (3/12 20% vs. 11/24, 46%, p=0.10).
Most of the patients (75%) had also extra muscular involvement including acrosyndrome (45%), interstitial lung disease (35%), sclerodactyly (30%), telangiectasia (25%), digital tip ulcer (10%), sclerodermy (5%). By contrast, no patient had polyarthrithis (vs. 20% in the controls, p<0.05). DM rash was hardly threefold less frequent in axial IM patients (15% vs. 42%, p<0.05).
Auto-antibodies associated with scleromyositis were the most frequent in axial-IM patients (30% vs. 10.3%, p=007, manly anti-PM/Scl). One patient (5%) had cancer within the 3 years before or after IM diagnosis (NS vs. controls).
Thus, most frequent diagnosis in axial IM-patients were scleromyositis (35% vs. 5% in the controls, p<0.05) and inclusion body myositis (20% vs. 2.6% in the controls, p<0.05). DM was twofold less frequent than in control (10% vs 41%, p<0.05). Other IM subtypes were not statistically different from the control groups.
Except patients with diagnosis of sIBM, all axial IM-patients received corticosteroids with another immunomodulatory drugs (median number 2, range 1–5). Half of the axial-IM patients received intravenous immunoglobulin. After a mean follow up of 68.4±3.76 months all patients had improvement, including in axial weakness, except in patients with sIBM. One patient died from ischemic cardiomyopathy.
Conclusions In IM, camptocormia and dropped head syndrome are associated with late onset scleromyositis and sIBM with delayed diagnosis.
Disclosure of Interest None declared