Relevance of neurocognition in chronic pain syndrome: a systematic and methodical approach.

INTRODUCTION: Subjective and objective deficits in neurocognitive domains are well-documented in patients with chronic pain. However, neurocognitive deficits have not been investigated consistently. The main objective of this study was to conduct a comprehensive assessment of self-rated and objectively assessed cognitive differences between patients with chronic pain (CP) and healthy controls (HC). METHOD: The cognitive functioning of 40 CP and 41 HC was assessed using a standardized computer-based test battery, enabling a comparison of subjective and objective neurocognitive factors. To achieve this, the Vienna Test System (VTS) was utilized, incorporating standardized tests from the Cognitive Basic Assessment Battery (COGBAT) with the advantage of objectivity, reliability, validity, efficiency, utility, and standardization. This approach enables the evaluation of cognitive functioning across all pertinent domains. RESULTS: CP reported cognitive deficits in overall performance as well as specific functions, such as attention, memory, and executive functions. Across all neurocognitive domains, CP showed a poorer performance. Affected subdomains of attention were intensity and selectivity of attention. Lower performance was found also in concentration performance, obtaining and overview, visual orientation performance and reactive stress tolerance. Regarding memory, CP performed worse in figural episodic memory and recognition tasks. In addition, CP exhibited poorer performance in mental flexibility, working memory, planning ability, and inhibition as components of executive functioning, when compared to HC. CONCLUSIONS: CP expressed subjective cognitive deficits and demonstrated impaired neurocognitive performance.

Neurocognitive Deficits and Effects of Cognitive Reserve in Mild Cognitive Impairment.

BACKGROUND/AIMS: Mild cognitive impairment (MCI) is a frequent syndrome in the older population, which involves an increased risk to develop Alzheimer's disease (AD). The latter can be modified by the cognitive reserve, which can be operationalized by the length of school education. MCI can be differentiated into four subtypes according to the cognitive domains involved: amnestic MCI, multiple-domain amnestic MCI, non-amnestic MCI and multiple-domain non-amnestic MCI. While neurocognitive deficits are a constituent of the diagnosis of these subtypes, the question of how they refer to the cognitive reserve still needs to be clarified. METHODS: We examined neuropsychological deficits in healthy controls, patients with MCI and patients with mild AD (n = 485) derived from a memory clinic. To reduce the number of neuropsychological variables, a factor analysis with varimax rotation was calculated. In a second step, diagnostic groups including MCI subtypes were compared with respect to their clinical and neuropsychological characteristics including cognitive reserve. RESULTS: Most MCI patients showed the amnestic multiple-domain subtype followed by the pure amnestic subtype, while the non-amnestic subtypes were rare. The amnestic subtype displayed a significantly higher level of cognitive reserve and higher MMSE scores than the amnestic multiple-domain subtype, which was in most cases characterized by additional psychomotor and executive deficits. CONCLUSIONS: These findings confirm earlier reports revealing that the amnestic multiple-domain subtype is the most frequent one and indicating that a high cognitive reserve may primarily prevent psychomotor and executive deficits in MCI.