Clinical Features of ALS and PDC

In the 1960s, the mean age of onset for ALS was in the 40s, and it increased to the 50s by 1980. PDC showed similar trends, with a mean age at onset in 1960 in the 50s, rising to the 60s by 1980. The mean age at onset of PDC in 2000 was 68.

Both diseases are more common in men than women. Survival rates after diagnosis were 3-4 yrs for ALS and 4-5 yrs for PDC.

Clinical Features II

  • Clinical signs for ALS include wasting, weakness, UMN signs and bulbar onset in about 20%.
  • For PDC, signs include Parkinsonism with rest tremor in approximately 40% of those affected.
  • There is only fair response to L-dopa therapy and gait ‘apraxia’ is common.
    Dementia is seen within 0-3 years of PD, and there is progressive loss of memory and language.
  • Behavioral symptoms were not prominent.

Clinical features III - Late-life Dementia resembles AD

  • ‘Mariana dementia’ was first mentioned in late 1980s
  • We diagnosed over 200 cases from 1997 - 2005
  • Mean age at onset is 75, increases with age
  • Affects women more than men
  • Typically starts with memory decline, then other cognitive areas
  • No cognitive differences from PDC
  • No significant Parkinsonism until stages of severe dementia