Fronto-Temporal Dementias

• This group makes up 25% of all dementias . It includes a group of syndromes characterized by degeneration of the frontal and temporal lobes.
• Also known as "Dysexecutive syndrome"
• Approximately 40% of cases are familial (Autosomal dominant) and a minority of these have been linked to a mutation in the Tau gene on Chromosome 17.
  • Tau is a microtubule associated glycoprotein which is the major component of paired helical filaments found in neurofibrillary tangles of Alzheimer's Disease
• A variety of FTD's have been associated with Tau gene mutations on Chromosome 17, including:
  • Pallido-ponto-nigral degeneration
  • Hereditary Pick's disease
  • Progressive subcortical gliosis
  • Hereditary dysphasic dementia
  • Disinhibition dementia pakinsonism amyotrophy complex

Clinical Features

• frequently encountered with poor judgement, behaviour and planning.
• Early disturbances in language
• Memory is typically less impaired than with Alzheimer's Disease
  • FTD's are involve more of a behavioural problem as opposed to a memory deficit
• Pathological Features:
  • In SPEC scan, frontal lobes are hypoperfused
  • Anterior frontal and temporal lobe atrophy
  • neuronal cell loss
  • gliosis
  • variety of neuronal inclusions