Myasthenia gravis incidence in a general North Atlantic isolated population

Objective – There are no previous studies undertaken about
myasthenia gravis in the Faroe Islands. The aim of this study was to
establish the incidence of onset of this disease in the Faroese
population. Method – Patients were ascertained and registered
prospectively from 1986 to 2013 when they were examined at the
Neurological Clinic of the Faroese National Hospital or at a private
neurological practice, which constitutes all the available neurological
services in the Faroe Islands. Result – Twelve new diagnoses were
made over a 27-year period, providing an incidence density rate of 9.4
per million person-years (95% confidence limit 4.9–16.5). At
presentation, nine of 12 patients had generalized myasthenia gravis
and two patients had pure ocular disease, and in one patient, the
symptoms were restricted to the bulbo-facial muscles. The sex ratio
was 2:1, F/M. In nine of the cases, a positive result of acetylcholine
receptor antibody assay was documented. In all patients, there was a
beneficial response to anticholinesterase administration. Conclusion –
The result yielded no strong evidence of a difference in incidence
between that found in the Faroe Islands and those in most European
studies, apart from recent studies from London, UK; Norway; Spain,
and Italy in which incidences from 21 to 30 per million person-years
had been reported.