Abstract
Dementia is broadly defined by DSM-V as cognitive decline from a previous level that
impacts the patient's functioning at work or play. This broad definition does not
provide information about the underlying disease process, an aspect of clinical care
that is of increasing importance, as therapeutic development inches closer to effective
disease-modifying treatments. The most common neurodegenerative dementias include
Alzheimer's disease, dementia with Lewy bodies, frontotemporal dementia, and Parkinson's
disease dementia. Although rare, the prion diseases constitute an important group
of dementias that should be routinely considered in the evaluation. Over the last
two decades, advances in neuroimaging, biomarker development, and neurogenetics have
not only led to a better understanding of the biology of these diseases, but they
have improved our awareness of less common clinical subtypes of dementia. As such,
to best define the disease process, the evaluation of a patient with cognitive decline
requires attention to a myriad of disease aspects, such as the primary symptom at
onset (memory, language, visual perception, praxis, etc.), the age at onset (younger
or older than 65 years), the rate of disease progression (weeks to months or years),
the cognitive and behavioral profile (neuropsychological assessment), and involvement
of physical findings. We present here three cases that highlight the decision-making
process in the evaluation of patients with atypical presentations of dementia.
Keywords
posterior cortical atrophy - frontotemporal dementia - Creutzfeldt–Jakob disease -
variably protease sensitive prionopathy - Alzheimer's disease - amyotrophic lateral
sclerosis
