Detection Of Underlying Dementia In Bullous Pemphigoid Patients Using Cognitive Evaluation Tests:A Case Control Study

Background:Preliminary observation in clinical practice showed that subjective neurocognitive complaints are relatively common in bullous pemphigoid patients.Yet,little has been done to investigate the neurocognitive status in bullous pemphigoid.Objective:To evaluate for differences in cognitive function between bullous pemphigoid patients and matched controls using two screening instruments:Mini-Mental State Examination(MMSE)and Montreal Cognitive Assessment(MoCA).Methods:This observational case-control study included 45 subjects with a confirmed diagnosis of bullous pemphigoid from January 2014 to October 2017,together with 64 matched controls,were recruited with detailed demographic and clinical data from the Department of Dermatology and Geriatrics,Peking Union Medical College Hospital.43 bullous pemphigoid subjects and 60 matched controls were successfully recruited.The patients underwent MMSE,MoCA and Hamilton depression scale(HAMD-17).Results:This study comprised 43 bullous pemphigoid patients and 60 matched control subjects.The overall scores were significantly lower in bullous pemphigoid than in controls(median[IQR],25.5[13]vs 27[4],PMMSE=0.027;17[15]vs 24.5[4.8],PMoCA<0.001).The percentage of patients screened positive for cognitive impairment in the bullous pemphigoid group was significantly higher than in the control group(27.9%vs 5%,PMMSE=0.001;88.3%vs 61.7%,PMoCA=0.003).On multivariate analysis,bullous pemphigoid was associated with increased odds of cognitive impairment by MMSE(Odds Ratio 5.17,95%CI[0.86-30.96])and MoCA(Odds Ratio 4.39,95%CI[1.42-13.58]).8 bullous pemphigoid subjects without any previous recorded neurological disease were referred to the neurologists due to abnormal screening results,of whom 4 patients were diagnosed with mild cognitive impairment and 3 with Alzheimer's disease.Conclusions:Bullous pemphigoid patients had decreased cognitive abilities and were at a higher risk of cognitive impairment.Our findings suggest that evaluation of cognitive impairment may be warranted for bullous pemphigoid patients in clinical practice for early diagnosis and therapy of dementia.