20 years of vertigo in a portuguese health care unit
Abstract
The authors have conducted a retrospective study in about 15,000 beneficiaries of Portugal Telecom/ACS who attended its ENT Department at its Health Care Unit of Lisbon, during a period of 20 years (1983-2003). 1001 patients with isolated or associated vertigo complaints were selected. Their analysis was sometimes difficult – owing to the scarce characterization of the complaints, poor diagnosis definition, patients lost to follow-up and patients with only one visit, etc. – and therefore a distribution by the different clinical entities was only possible in 57% of the cases. In these patients we were able to identify: BPPV (28%), Menière’s disease and other types of vertigo evolving by crises (12%), neuritis/labyrinthitis (7%), central vertigo (5%), vascular diseases (1%), tumours (1%), and other causes (3%). These values present some degree of distortion, namely the low significance of vertigo with central topography, which is observed primarily in Neurology. The nosologic identification of peripheral vertigo instead provides reasonable assurance. The high percentage of non-identified clinical pictures is due, among other factors, to a deficient characterization, to referral to other specialties and to not considering vertigo of psychogenic origin.
Based on these results, the authors tried further to establish the prevalence of Menière’s disease in the Lisbon area, including the districts in the northern and southern banks of the river Tejo, where about 2,5 million people were surveyed (2547916) in the last Census (2001). The study covered all the councils in the Metropolitan Area of Lisbon (Grande Lisboa) and the major part of the peninsula of Setubal (Alcochete, Almada, Barreiro, Moita, Montijo, Palmela, Seixal and Sesimbra), to which corresponds a sample of 32 073 users of the “Health Care Unit of Lisbon” of the PT-ACS. These data allowed us to estimate a prevalence between 0.19% and 0.25%, depending on whether Menière’s disease was classified only according to the definition of the AAO-HNS guidelines as definite or including probable and possible cases.
