Citations

Abstract Delayed diagnosis of immune-mediated necrotizing myopathy leads to increased morbidity. Patients with the chronic course without 3-hydroxy-3-methylglutaryl-coenzyme-A reductase-IgG or signal recognition particle-IgG are often challenging to diagnose. Immunotherapy response can also be difficult to assess. We created a statistical model to assist immune-mediated necrotizing myopathy diagnosis. Electrical myotonia versus fibrillations were reviewed as biomarkers for immunotherapy treatment response. Identified were 119 immune-mediated necrotizing myopathy cases and 938 other myopathy patients. Inclusion criteria included all having electrophysiological evaluations, muscle biopsies showing inflammatory/necrotizing myopathies, comprehensively recorded neurological examinations, and creatine kinase values. Electrical myotonia was recorded in 56% (67/119) of retrospective and 67% (20/30) of our validation immune-mediated necrotizing myopathy cohorts, and significantly (P < 0.001) favoured immune-mediated necrotizing myopathy over other myopathies: sporadic inclusion body myositis (odds ratio = 4.78); dermatomyositis (odds ratio = 10.61); non-specific inflammatory myopathies (odds ratio = 8.46); limb-girdle muscular dystrophies (odds ratio = 5.34) or mitochondrial myopathies (odds ratio = 14.17). Electrical myotonia occurred in immune-mediated necrotizing myopathy seropositive (3-hydroxy-3-methylglutaryl-coenzyme-A reductase-IgG 70%, 37/53; signal recognition particle-IgG 29%, 5/17) and seronegative (51%, 25/49). Multivariate regression analysis of 20 variables identified 8 (including electrical myotonia) in combination accurately predicted immune-mediated necrotizing myopathy (97.1% area-under-curve). The model was validated in a separate cohort of 30 immune-mediated necrotizing myopathy cases. Delayed diagnosis of cases with electrical myotonia occurred in 24% (16/67, mean 8 months; range 0–194). Half (8/19) had a chronic course and were seronegative, with high model prediction (>86%) at the first visit. Inherited myopathies were commonly first suspected in them. Follow-up evaluation in patients with electrical myotonia on immunotherapy was available in 19 (median 21 months, range 2–124) which reduced from 36% (58/162) of muscles to 7% (8/121; P < 0.001). Reduced myotonia correlated with immunotherapy response in 64% (9/14) as well as with median creatine kinase reduction of 1779 U/l (range 401–9238, P < 0.001). Modelling clinical features with electrical myotonia is especially helpful in immune-mediated necrotizing myopathy diagnostic suspicion among chronic indolent and seronegative cases. Electrical myotonia favours immune-mediated necrotizing myopathy diagnosis and can serve as an adjuvant immunotherapy biomarker.

Abstract Our study aims to quantitate neuromuscular morbidity from radiotherapy in Hodgkin lymphoma including: (i) frequency and (ii) time of onsets for neurological localizations; (iii) degree of disabilities and (iv) number of clinical visits compared to cardiopulmonary Hodgkin lymphoma-radiation complications. Medical records from Mayo Health systems were retrieved; identifying neuromuscular radiation treated Hodgkin lymphoma-complications from 1 January 1994 to 31 December 2016. Of an estimated 4100 post-radiotherapy Hodgkin lymphoma patients, 4.6% (189) were identified with complications. Mean latency to physician visit for symptoms was 23.7 years (range: 1–50). Most commonly identified complications included: head drop 10% (19) with or without myopathy, myopathy 39% (73), plexopathy 29% (54), myelopathy 27% (51) and polyradiculopathy 13% (24). Other findings included benign and malignant nerve sheath tumours 5% (9), phrenic and long thoracic mononeuropathies 7% (14) and compressive spinal meningioma 2% (4). Patients frequently had multiple coexisting complications (single = 76% [144], double = 17% [33], triple = 4% [8], quadruple = 2% [4]). Cardiac 28% (53) and pulmonary 15% (29) complications were also seen in these patients. History of Hodgkin lymphoma was initially overlooked by neurologists (14.3%, 48/336 clinical notes). Hospital and outpatient visits for complications were frequent: neuromuscular 19% (77/411) versus cardiopulmonary 30% (125/411). Testing was largely exclusionary, except when imaging identified secondary malignancy. Modified Rankin score at diagnosis varied: 0–1 (55.8%), 2–3 (5.8%) and 4–5 (38.3%). Neuromuscular complications among post-radiation Hodgkin lymphoma are diverse, occurring in ∼1 of 20 having markedly delayed onsets often eluding diagnosis. Frequent care visits and major morbidity are common. Survivorship recommendations should recognize the diverse neurological complications.