Left-handedness in early and late onset dementia

Area of Science:

• Neurology
• Neuroscience
• Geriatrics

Background:

• Alzheimer's disease is a progressive neurodegenerative disorder.
• Dementia is categorized by age of onset: presenile (before 65) and senile (after 65).
• Handedness, a marker of brain lateralization, has been explored in relation to neurological conditions.

Purpose of the Study:

• To investigate the relationship between age of onset in Alzheimer's disease and handedness.
• To explore potential biological distinctions between early-onset and late-onset Alzheimer's disease.

Main Methods:

• Sixty-five male patients diagnosed with Alzheimer's disease were recruited.
• Participants were divided into two groups based on age of onset: before or after 65 years.
• A handedness questionnaire was administered to all participants.

Main Results:

• A significantly higher prevalence of left-handedness was observed in the early-onset group (onset before 65).
• The late-onset group (onset after 65) exhibited a lower prevalence of left-handedness.
• These findings indicate a potential association between handedness and the age of dementia onset.

Conclusions:

• The observed difference in left-handedness prevalence suggests that presenile and senile dementia of the Alzheimer type may not be biologically identical.
• Handedness could serve as a potential indicator for differentiating subtypes of Alzheimer's disease.
• Further research is warranted to elucidate the underlying biological mechanisms linking handedness and Alzheimer's disease subtypes.