A population-based epidemiologic study of adult neuromuscular disease in the Republic of Ireland
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University College Cork
This research project generates for the first time prevalence rates (PR) for all adult neuromuscular diseases (NMD) as well as the incidence rates (IR) for Guillain-Barre syndrome (GBS) in the Republic of Ireland (ROI). Multiple case ascertainment sources were used to achieve as complete as possible case ascertainment to accurately estimate the country-wide prevalence. Acquired demyelinating polyneuropathies represented the biggest cohort (26.0%) followed by muscular dystrophies (22.5%) and myasthenia gravis (19.7%). For GBS, in the 20 year period (1992 to 2012), comparable with other international studies, incidence rates of 0.3-1.3 per 100,000 person-years were attained. Higher PR figures for chronic inflammatory demyelinating polyneuropathy and sporadic inclusion body myositis were found (5.87 per 100,000 and 11.7 per 100,000 in those older than 50 year, respectively) compared with previous studies. The PR for myasthenia gravis in ROI is comparable with countries such as Australia, Italy and Norway but is lower than in Northern Ireland. The PR for Charcot-Marie-Tooth disease and limb girdle muscular dystrophies were similar with United Kingdom PR; however, a definite diagnosis was attained in only one third of Irish patients. Given the fact that paediatric cases were excluded from our study, lower PR figures were obtained for dystophinopathies. Interestingly, the PR for myotonic dystrophy type 1 and facioscapulohumeral muscular dystrophy (FSHD) in the ROI was lower than in United Kingdom but not considerably. A high PR for periodic paralysis (PP) was found in our study, nearly ten times higher for Hyper PP and as twice as high for Hypo PP when compared with figures from England; however, the ROI figures were derived from large families suggesting a founder effect. Of all the inherited NMD, 46% of cases had a definite histopathology and/or genetic diagnosis. The combined PR for inherited and acquired NMD was high, 62.6 per 100,000, when compared with other chronic neurological diseases in ROI. During the course of the study, a definite genetic diagnosis was achieved in families with rare previously unreported NMD in ROI, such as Laing distal myopathy, Andersen Tawil syndrome and FSHD2. This research defines the burden of NMD in the ROI, raises awareness of these conditions, will facilitate earlier intervention where appropriate and will provide a strong argument for service provision for these patients. This research project will serve as a useful originator for future research studies, especially with regard to obtaining genetic confirmation of currently undefined cases.
Neurology , Nervous system , Diseases , Central nervous system
Lefter, S. 2014. A population-based epidemiologic study of adult neuromuscular disease in the Republic of Ireland. MD Thesis, University College Cork.