Figure 2

The neuropsychological course. At time point 1 (T1) the patient suffered from acoustic illusions, incoherence of thought, psychomotor agitation, mood instability and speech dysfunction (perseveration and neologisms). Mini-Mental-Status-Examination (MMSE: 22/30) showed clinically relevant cognitive impairment. Psychomotor speed assessed by the Trail-Making-Test-A (TMT-A) was average, cognitive flexibility/task switching (TMT-B), verbal memory span, working memory and semantic category verbal fluency were below average (percentile rank < 16). At T2, formal neuropsychological testing was not feasible due to clouding of consciousness, mutism and pronounced psychomotor slowing. Moreover, the patient displayed undirected utilization behaviour suggestive of severe frontal lobe dysfunction. At T3, neuropsychological functioning was considerably improved. MMSE was inconspicuous (30/30). With the exception of discrete impairment regarding verbal memory span, formal neuropsychological testing revealed above average psychomotor speed (TMT-A) and cognitive flexibility (TMT-B), average working memory and executive functioning as measured by semantic category verbal fluency. Interestingly, phonemic verbal fluency, which is considered to involve frontal cognitive control even more than semantic category tasks, was below average, possibly hinting at a subtle residual executive impairment.