Creutzfeldt-Jakob disease in Sweden

OBJECTIVES—To find and investigate,retrospectively, as many cases as possible ofCreutzfeldt-Jakob disease (CJD) in Sweden dying during the period1 January 1985 to 31 December 1996 and to detect any possible case(s)of new variant CJD.
METHODS—The patients were found through computersearch of all death certificates in Sweden on which CJD was mentioned,through information from the Swedish neuropathologists, and spontaneousreports from Swedish doctors and hospitals. Data concerning thepatients were then collected from patients' case records and frombrain histopathology reports.
RESULTS—In total 72 cases of spongiformencephalopathy were confirmed as definite by neuropathology, one ofthem with Gerstmann-Stäussler-Scheinker disease. In 51 further casesthere were no brain pathology data but the diagnosis "probable" (37 patients) or "possible" (14 patients) CJD according to WHO criteriacould be made on clinical grounds. There was a variation in number ofdeaths/year, from a minimum of five (1985) to a maximum of 16 (1990).Sixty patients died during the period 1985-90 and 62 during 1991-6.The sex ratio was nearly 1:1. Calculated for a population of 8.6 million (mean of 12 years) in Sweden this gives 1.18/million/year. Ageat the time of the presenting symptoms ranged from 34 to 84 years. Only one patient was under 40 at the onset of symptoms. He had a spongiform encephalopathy but prion protein staining was negative. The duration ofsymptoms that could be attributed to CJD was 6 months or less in 75 cases, 7-12 months in 16 cases, 1 to 2 years in 15 cases, and morethan 2 years in 16 patients. By definition all patients were demented.Other more common symptoms and signs were aphasia, dysphasia,dysathria, ataxia, myoclonus, pareses of the extremities, rigidity orspasticity, different types of hyperkinesias, and other psychiatricsymptoms (depression, anxiety, and aggressiveness). Less commonsymptoms were hallucinations (mainly visual), visual defects, sensorysymptoms (paraesthesias, itching, or pain), apraxia of swallowing, anddisorders of eye movements.
CONCLUSIONS—The incidence, the symptomatology, theage distribution (age in years at onset and at death), and the durationof illness were similar to those of other countries except for thecases of new variant CJD in the United Kingdom. There is so far noindication of any cases of new variant CJD in Sweden.