Epidemiology of functional stroke mimic patients: a systematic review and meta-analysis

Stroke mimics form a significant proportion of cases in acute stroke services and some present with functional neurological disorder. Little is known about the prevalence or clinical characteristics of functional stroke mimics (FSMs). A systematic literature search and meta-analysis were carried out on published studies reporting suspected stroke and stroke mimic rates; 114 papers met the inclusion criteria of which 70 provided an FSM rate. Random-effects models estimated prevalence rates across settings and moderators of FSM rate. Pooled proportions indicated that 25% [95% confidence intervals (CI), 22-27%] of suspected stroke cases were stroke mimics. Within the 67 studies providing positive FSM rates, FSMs represented 15% (95% CI, 13-18%) of stroke mimics and 2% (95% CI, 2-3%) of suspected strokes. FSMs were younger and more likely to be female, and presented more with weakness/numbness but less with reduced consciousness or language problems. Stratified analyses suggested higher stroke mimic rates in primary care versus acute settings (38% vs. 12%) but higher FSM rates in stroke units compared with primary care (24% vs. 12%). Functional rates were higher in studies that were descriptive, retrospective and in patients receiving thrombolysis. Several studies reported the proportion of functional stroke patients presenting to stroke services. FSMs have discernible demographic and clinical characteristics, but there is a conspicuous lack of evidence on their presentation or guidance for treatment. The social and psychological mechanisms underlying FSM presentations need more accurate quantification to help inform stroke pathways and improve care for these patients.