Table 1

Direct-evidence studies on the association between OH and cognitive impairment

StudyDesignComparisonOH testingMain cognitive end pointsOutcome
Peralta et al40*C-SPD, N=10
PDD, N=8		Tilt tableMMSE
Attention, verbal fluency Verbal memory

  • OH worse in PDD vs PD

  • Tilt produced worse attention in PDD

Idiaquez et al41C-SPD, N=29
PDD, N=11		Orthostatic BPMMSE
FAB

  • OH same in PDD vs PD

  • PDD reported more cardiovascular symptoms

Hohler et al42*C-SPD+OH, N=17
PD−OH, N=27		Orthostatic BPMMSE
FIM (cognitive items)

  • PD+OH: worse MMSE and lower cognitive FIM

Bae et al43C-SPD+OH, N=18
PD−OH, N=27		Tilt tableSNSB: executive, attention, language, visuospatial, memory

  • Verbal memory was worse in the OH+ group

Pilleri et al44*C-SPD+OH, N=23
PD−OH, N=25		Tilt tableMMSE
FAB

  • MMSE same +OH and −OH

  • PD+OH: worse in attention visuospatial working memory and delayed verbal recall

Anang et al45*Prospective cohortPD, N=80 at 4.4 yearsOrthostatic BPTests of executive, attention, memory and visuospatial domains

  • 27/80 developed PDD

  • OH associated with dementia risk: OR=1.84 per 10 mm Hg BP drop

Kim et al46*C-SPD, N=25
PD-MCI, N=48
PDD, N=14		Tilt tableMMSE
CDR
SNSB: executive, attention, language, visuospatial, memory

  • OH in 71% of PDD vs 20% of PD

  • OH correlated with verbal immediate and delayed memory

Allcock et al47C-SPD+OH, N=42
PD−OH, N=45		Orthostatic BPMMSE

  • MMSE same in +OH and −OH

Allcock et al48C-SPD+OH, N=80
PD−OH, N=79		Orthostatic BPMMSE

  • MMSE same in +OH and −OH

Allcock et al37*C-SPD+OH, N=87
PD−OH, N=88		Orthostatic BPMMSE
Computerised testing

  • MMSE same in +OH and −OH

  • OH+ worse in digit vigilance and visual episodic memory

  • *Indicates a positive association.

  • BP, blood pressure; C-S, cross-sectional; CDR, clinical dementia rating scale; FAB, Frontal Assessment Battery; FIM, functional independence measure; MCI, mild cognitive impairment; MMSE, mini-mental state examination; +OH, orthostatic hypotension present; −OH, orthostatic hypotension absent; PD, Parkinson's disease; SNSB, Seoul Neuropsych Screening Battery.