A revised neuropsychological test battery, CoCoBattery-Plus, for the diagnosis of HIV-associated neurocognitive disorders in Japan

To diagnose HIV-associated neurocognitive disorders (HAND), several neuropsychological test batteries have been used in various studies and countries. In Japan, the Co-developing Comprehensive Neuropsychological Test Battery (CoCoBattery) was developed during a nationwide study conducted between 2014 and 2016 (the J-HAND study) to explore the prevalence of HAND and has been widely used thereafter. It consists of 14 tests covering eight key cognitive domains: language, attention/working memory, executive function, learning, memory, information-processing speed, visuospatial construction, and motor skills. However, some cases have been difficult to classify in terms of HAND severity due to the lack of subjective impairment assessments in CoCoBattery. Therefore, we added cognitive screening questions to CoCoBattery (CoCoBattery-Plus) and compared the results among 103 HIV-positive individuals. Using the original battery, 10 cases were diagnosed with HIV-associated dementia (HAD), 13 with mild neurocognitive disorder (MND), 39 with asymptomatic neurocognitive impairment (ANI), and 41 with no HAND. In contrast, using the new battery, four individuals who were previously unaware of cognitive impairment reported subjective complaints in response to the questions, leading to diagnostic changes: one case from ANI to HAD and three from ANI to MND. The final diagnoses were 11 HAD, 16 MND, and 35 ANI, corresponding to a reclassification rate of 3.9%. Subjective complaints are a crucial component in determining the severity of HAND, and we anticipate that CoCoBattery-Plus will enable more accurate HAND diagnosis.