In a recent Johns Hopkins study, researchers sought to use a systematic approach to characterizing PTLDS based on the most current consensus diagnosis. In addition, they examined PTLDS-related cognitive decline, operationalized as a significant decline in cognitive test performance relative to premorbid cognitive ability.
The study enrolled 124 patients with conﬁrmed PTLDS deﬁned by the Infectious Diseases Society of America’s proposed case deﬁnition. Cognitive functioning was evaluated using standardized neuropsychological measures of attention, memory, processing speed, and test engagement.
The majority (92%) of participants with PTLDS reported symptoms of cognitive difﬁculty to some degree. Objective evidence of cognitive decline (compared to estimated pre-morbid function) was identified in 26% of participants, with the most robust findings in verbal memory and processing speed. A subset (22% of those with decline) also showed objective evidence of cognitive impairment compared to population-level performance. Despite subjective symptoms, 50% of the sample showed no statistically or clinically signiﬁcant objective decline in cognitive function using standardized neuropsychological measures. The remaining 24% of the sample were found to have sub-optimal engagement on testing measures, which may be due to the impact of fatigue, pain, prior negative clinical experiences, or other unknown factors.
The current ﬁndings support objective evidence of cognitive decline and impairment in subsets of patients with PTLDS in distinct areas of cognitive functioning, especially verbal memory and processing speed. Further studies are needed to better understand the patient subjective experience of cognitive decline as well as the factors associated with objective cognitive decline to better manage symptoms of PTLDS and improve health related quality of life.
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