Table 1.

Algorithm for diagnosing PD-D at Level I (Level I testing) [11]

1 A diagnosis of PD based on the UK Parkinson's Disease Society Brain Bank criteria [12]

2 PD developed prior to the onset of dementia

3 An MMSE [23] score <26

4 Cognitive deficits severe enough to affect daily living (caregiver interview or Pill Questionnaire)

5 Impairment in ≥2 of the following tests:

– Months reversed or seven backward (attention)1

– Lexical fluency or clock drawing (executive function)1

– MMSE pentagons (visuospatial function)1

– Three-word recall (memory)1

For a diagnosis of probable PD-D, all the criteria in this table must be fulfilled. The presence of apathy, depressed mood, delusions, or excessive daytime sleepiness may support the diagnosis of probable PD-D. The presence of major depression, delirium, or any other abnormality that may by itself cause significant cognitive impairment makes the diagnosis uncertain.

¹Relevant cognitive domain.