The incidence and lifetime prevalence of neurological disorders in a prospective community-based study in the UK

Over an 18-month period, all incident cases of neurological disorders were ascertained prospectively in an unselected urban population based in 13 gen eral practices in the London area by a General Practice Linkage Scheme with the National Hospital for Neurology and Neurosurgery. In three of these pr actices, the lifetime prevalence of neurological disorders was also assesse d. A population of 100 230 patients registered with participating general p ractices was followed prospectively for the onset of neurological disorders . Multiple methods of case finding were used to maintain accuracy. The age- and sex-adjusted incidence rates of neurological disorders were calculated . The lifetime prevalence of neurological disorders was surveyed in 27 658 of the patients. The age- and sex-adjusted incidence rates were calculated for major neurological conditions. [These are expressed as rates per 100 00 0 persons per annum, with 95% confidence intervals (CI) in parentheses]. Th e commonest of these were first cerebrovascular events, 205 (CI: 183, 230); shingles, 140 (CI: 104, 184); diabetic polyneuropathy, 54 (CI: 33, 83); co mpressive neuropathies, 49 (CI: 39, 61); epilepsy, 46 (CI: 36, 60); Parkins on's disease, 19 (CI: 12, 27); peripheral neuropathies, 15 (CI: 9, 23); CNS infections, 12 (CI: 5, 13); post-herpetic neuralgia, 11 (CI: 6, 17); and m ajor neurological injuries, 10 (CI: 4, 11). Lifetime prevalence rates are a lso reported (expressed as rate per 1000 persons with 95% CI). The most pre valent conditions were: completed stroke, 9 (CI: 8, 11); transient ischaemi c attacks, 5 (CI: 4, 6); active epilepsy, 4 (CI: 4, 5); congenital neurolog ical deficit, 3 (CI: 3, 4); Parkinson's disease, 2 (CI: 1, 3); multiple scl erosis, 2 (CI: 2, 3); diabetic polyneuropathy, 2 (CI: 1, 3); compressive mo noneuropathies, 2 (CI: 2, 3); and sub-arachnoid haemorrhage, 1 (CI: 0.8, 2) . Overall, the onset of 625 neurological disorders was observed per 100 000 population annually. Six percent of the population had at some time had a neurological disorder. This is the first study of the incidence and lifetim e prevalence of neurological disorders in recent times; we found that these disorders give rise to significant morbidity in the community.