title: The prevalence of frontal variant frontotemporal dementia and the frontal lobe syndrome in a population based sample of 85 year olds.
abstract: OBJECTIVE
  To investigate the prevalence of the frontal lobe syndrome (FLS) and the frontal variant of frontotemporal dementia (fvFTD) in a population based sample of 85 year olds.
  
  
  METHODS
  A representative sample of 85 year olds (n = 451) in Gothenburg, Sweden was examined with a neuropsychiatric examination and a key informant interview performed by an experienced psychiatrist. A subsample underwent computed tomography (CT) of the head. The Lund-Manchester research criteria were used as a basis for a symptom algorithm to identify individuals with FLS and fvFTD. These were diagnosed blindly to the diagnosis of dementia according to DSM-III-R.
  
  
  RESULTS
  A total of 86 individuals (19%) fulfilled the criteria for FLS, and 14 of them fulfilled criteria for fvFTD. There were no differences between men and women. Among those with FLS, 75 (87%) fulfilled DSM-III-R criteria for other types of dementia, mainly Alzheimer's disease and vascular dementia. Among the 14 fvFTD cases, only five were demented according to DSM-III-R. Moderate to severe frontal atrophy was found in 93% of those with FLS (and in all cases with fvFTD), but also in 49% of those without FLS. FLS was found in 35% of those with moderate to severe frontal atrophy, and in 3% of those without these changes.
  
  
  CONCLUSIONS
  The prevalence of fvFTD was 3% in 85 year olds, which is higher than previously expected in this age group. Only a minority of those with fvFTD were detected by the DSM-III-R criteria for dementia. FLS was even more common, especially in those diagnosed with a dementia disorder.
authors.affiliation: The Institute of Clinical Neuroscience, Department of Psychiatry, Sahlgrenska Hospital, Gothenburg, Sweden.
authors.forename: T B
authors.initials: TB
authors.lastname: Gislason
authors.forename: M
authors.initials: M
authors.lastname: Sjögren
authors.forename: L
authors.initials: L
authors.lastname: Larsson
authors.forename: I
authors.initials: I
authors.lastname: Skoog
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D003704:Dementia / Q000453:epidemiology* / Q000473:pathology; D005260:Female; D005625:Frontal Lobe / Q000473:pathology*; D006801:Humans; D008297:Male; D015995:Prevalence; D013548:Sweden / Q000453:epidemiology; D013577:Syndrome; D014057:Tomography, X-Ray Computed