Signs and symptoms method in neuropsychology: A standardized observational examination of cognitive functions can be effective in detecting mild cognitive impairment.

OBJECTIVE: The present study aimed at investigating the sensitivity and specificity of the NeuroPsychological Examination (NPE), a systematic collection of cognitive signs and symptoms based on the observation of the patient's behavior during a clinical interview, in detecting Mild Cognitive Impairment (MCI). METHOD: 475 participants, 208 suffering from MCI, 188 suffering from dementia and 79 subjective cognitive decline (SCD), have been assessed using NPE for the presence of signs and symptoms of cognitive impairment. Receiver operating characteristic (ROC) curve analysis and the Youden's test were used to determine the more appropriate cutoff points for the number of neuropsychological signs at the NPE that enabled to discriminate SCD from MCI, SCD from dementia and MCI from dementia. A sensitivity and specificity analysis and comparisons among the three groups were conducted. RESULTS: The mean number of signs at the NPE were 1.73 for SCD, 7.98 for MCI and 12.82 for dementia. Pairwise comparisons among the three group of participants showed significant differences (SCD vs. MCI, p < .001, r = -0.66; SCD vs. dementia, p < .001, r = -0.76; MCI vs. dementia, p < .001, r = -0.44). The criterion of 3 signs at the NPE showed a sensitivity of 0.95 (95% CI [0.91, 0.97]) and a specificity of 0.76 (95% CI [0.65, 0.84]) in discriminating SCD from MCI participants. CONCLUSIONS: A signs and symptoms approach could be a useful tool for clinical neuropsychologists working in the field of MCI and dementia assessment. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Diencephalic versus Hippocampal Amnesia in Alzheimer's Disease: The Possible Confabulation-Misidentification Phenotype.

BACKGROUND: Alzheimer's disease (AD) is clinically heterogeneous, including the classical-amnesic (CA-) phenotype and some variants. OBJECTIVE: We aim to describe a further presentation we (re)named confabulation-misidentification (CM-) phenotype. METHODS: We performed a retrospective longitudinal case-series study of 17 AD outpatients with the possible CM-phenotype (CM-ADs). Then, in a cross-sectional study, we compared the CM-ADs to a sample of 30 AD patients with the CA-phenotype (CA-ADs). The primary outcome was the frequency of cognitive and behavioral features. Data were analyzed as differences in percentage by non-parametric Chi Square and mean differences by parametric T-test. RESULTS: Anterograde amnesia (100%) with early confabulation (88.2%), disorientation (88.2%) and non-infrequently retrograde amnesia (64.7%) associated with reduced insight (88.2%), moderate prefrontal executive impairment (94.1%) and attention deficits (82.3%) dominated the CM-phenotype. Neuropsychiatric features with striking misidentification (52.9%), other less-structured delusions (70.6%), and brief hallucinations (64.7%) were present. Marked behavioral disturbances were present early in some patients and very common at later stages. At the baseline, the CM-ADs showed more confabulation (p < 0.001), temporal disorientation (p < 0.02), misidentification (p = 0.013), other delusions (p = 0.002), and logorrhea (p = 0.004) than the CA-ADs. In addition, more social disinhibition (p = 0.018), reduction of insight (p = 0.029), and hallucination (p = 0.03) persisted at 12 months from baseline. Both the CA- and CM-ADs showed anterior and medial temporal atrophy. Compared to HCs, the CM-ADs showed more right fronto-insular atrophy, while the CA-ADs showed more dorsal parietal, precuneus, and right parietal atrophy. CONCLUSION: We described an AD phenotype resembling diencephalic rather than hippocampal amnesia and overlapping the past-century description of presbyophrenia.

Autonomic function predicts cognitive decline in mild cognitive impairment: Evidence from power spectral analysis of heart rate variability in a longitudinal study.

Background: Despite the emerging clinical relevance of heart rate variability (HRV) as a potential biomarker of cognitive decline and as a candidate target for intervention, there is a dearth of research on the prospective relationship between HRV and cognitive change. In particular, no study has addressed this issue in subjects with a diagnosis of cognitive status including cognitive impairment. Objective: To investigate HRV as a predictor of cognitive decline in subjects with normal cognition (NC) or Mild Cognitive Impairment (MCI). Specifically, we tested the literature-based hypothesis that the HRV response to different physical challenges would predict decline in different cognitive domains. Methods: This longitudinal study represents the approximately 3-year follow-up of a previous cross-sectional study enrolling 80 older outpatients (aged ≥ 65). At baseline, power spectral analysis of HRV was performed on five-minute electrocardiographic recordings at rest and during a sympathetic (active standing) and a parasympathetic (paced breathing) challenge. We focused on normalized HRV measures [normalized low frequency power (LFn) and the low frequency to high frequency power ratio (LF/HF)] and on their dynamic response from rest to challenge (Δ HRV). Extensive neuropsychological testing was used to diagnose cognitive status at baseline and to evaluate cognitive change over the follow-up via annualized changes in cognitive Z-scores. The association between Δ HRV and cognitive change was explored by means of linear regression, unadjusted and adjusted for potential confounders. Results: In subjects diagnosed with MCI at baseline a greater response to a sympathetic challenge predicted a greater decline in episodic memory [adjusted model: Δ LFn, standardized regression coefficient (ß) = -0.528, p = 0.019; Δ LF/HF, ß = -0.643, p = 0.001] whereas a greater response to a parasympathetic challenge predicted a lesser decline in executive functioning (adjusted model: Δ LFn, ß = -0.716, p < 0.001; Δ LF/HF, ß = -0.935, p < 0.001). Conclusion: Our findings provide novel insight into the link between HRV and cognition in MCI. They contribute to a better understanding of the heart-brain connection, but will require replication in larger cohorts.

Signs and symptoms method in neuropsychology: A preliminary investigation of a standardized clinical interview for assessment of cognitive decline in dementia.

Psychologists usually perform a preliminary assessment of the person's cognitive status through a brief interview conducted before the formal testing. However, this exam has not yet been standardized with ad hoc recommendations in psychology literature. In this work, a standard observational NeuroPsychological Examination (NPE) designed for psychologists was proposed, and its clinical effectiveness evaluated. The NPE was administered to patients referred to a neuropsychological service in a memory clinic over a 2-year period. The NPEs of the patients with Alzheimer dementia (AD), vascular dementia (VaD), and healthy controls (HC) were retrospectively retrieved. Comparisons among the three groups were conducted. Abnormalities/signs identified during the NPE in the AD and VaD groups are more numerous compared to those reported in the HC group. About 80% of HCs show none or only one abnormal sign. Vice versa, 87.5% of both AD and VaD patients show three or more abnormalities. Accordingly, the NPE has 0.88 (95%CI = 0.81-0.95) sensitivity and 0.95 (95%CI = 0.88-1.02) specificity for detecting cognitive decline when a cut-point of three or more signs is applied. Some significant differences also emerge on the number of pathological signs between AD and VaD patients. NPE is a promising tool with demonstrated diagnostic utility in dementia patients.

Autonomic function in amnestic and non-amnestic mild cognitive impairment: spectral heart rate variability analysis provides evidence for a brain-heart axis.

Mild cognitive impairment (MCI) is a heterogeneous syndrome with two main clinical subtypes, amnestic (aMCI) and non-amnestic (naMCI). The analysis of heart rate variability (HRV) is a tool to assess autonomic function. Cognitive and autonomic processes are linked via the central autonomic network. Autonomic dysfunction entails several adverse outcomes. However, very few studies have investigated autonomic function in MCI and none have considered MCI subtypes or the relationship of HRV indices with different cognitive domains and structural brain damage. We assessed autonomic function during an active orthostatic challenge in 253 oupatients aged ≥ 65, [n = 82 aMCI, n = 93 naMCI, n = 78 cognitively normal (CN), neuropsychologically tested] with power spectral analysis of HRV. We used visual rating scales to grade cerebrovascular burden and hippocampal/insular atrophy (HA/IA) on neuroimaging. Only aMCI showed a blunted response to orthostasis. Postural changes in normalised low frequency (LF) power and in the LF to high frequency ratio correlated with a memory test (positively) and HA/IA (negatively) in aMCI, and with attention/executive function tests (negatively) and cerebrovascular burden (positively) in naMCI. These results substantiate the view that the ANS is differentially impaired in aMCI and naMCI, consistently with the neuroanatomic substrate of Alzheimer's and small-vessel subcortical ischaemic disease.

The guilty brain: the utility of neuroimaging and neurostimulation studies in forensic field.

Several studies have aimed to address the natural inability of humankind to detect deception and accurately discriminate lying from truth in the legal context. To date, it has been well established that telling a lie is a complex mental activity. During deception, many functions of higher cognition are involved: the decision to lie, withholding the truth, fabricating the lie, monitoring whether the receiver believes the lie, and, if necessary, adjusting the fabricated story and maintaining a consistent lie. In the previous 15 years, increasing interest in the neuroscience of deception has resulted in new possibilities to investigate and interfere with the ability to lie directly from the brain. Cognitive psychology, as well as neuroimaging and neurostimulation studies, are increasing the possibility that neuroscience will be useful for lie detection. This paper discusses the scientific validity of the literature on neuroimaging and neurostimulation regarding lie detection to understand whether scientific findings in this field have a role in the forensic setting. We considered how lie detection technology may contribute to addressing the detection of deception in the courtroom and discussed the conditions and limits in which these techniques reliably distinguish whether an individual is lying.

Transcranial direct current stimulation (tDCS) for fatigue in multiple sclerosis.

BACKGROUND: The debilitating fatigue that patients with multiple sclerosis (MS) commonly experience during day-to-day living activities responds poorly to current therapeutic options. Direct currents (DC) delivered through the scalp (transcranial DC stimulation or tDCS) at weak intensities induce changes in motor cortical excitability that persist for almost an hour after current offset and depend on current polarity. tDCS successfully modulates cortical excitability in various clinical disorders but no information is available for MS related fatigue. OBJECTIVE: In this study we aimed to assess fatigue symptom after five consecutive sessions of anodal tDCS applied over the motor cortex in patients with MS. METHODS: We enrolled 25 patients with MS all of whom experienced fatigue. We delivered anodal and sham tDCS in random order in two separate experimental sessions at least 1 month apart. The stimulating current was delivered for 15 minutes once a day for 5 consecutive days. In each session the Fatigue Impact Scale (FIS) and the Back Depression Inventory (BDI) were administered before the treatment (baseline), immediately after treatment on day five (T1), one week (T2) and three weeks (T3) after the last tDCS session. RESULTS: All patients tolerated tDCS well without adverse events. The fatigue score significantly decreased after anodal tDCS in 65% of the patients (responders). After patients received tDCS for 5 days their FIS scores improved by about 30% and the tDCS-induced benefits persisted at T2 and T3. CONCLUSION: Our preliminary findings suggest that anodal tDCS applied over the motor cortex, could improve fatigue in most patients with MS.

Counterfactual thinking in Tourette's syndrome: a study using three measures.

Pathophysiological evidence suggests an involvement of frontostriatal circuits in Tourette syndrome (TS) and cognitive abnormalities have been detected in tasks sensitive to cognitive deficits associated with prefrontal damage (verbal fluency, planning, attention shifting, working memory, cognitive flexibility, and social reasoning). A disorder in counterfactual thinking (CFT), a behavioural executive process linked to the prefrontal cortex functioning, has not been investigated in TS. CFT refers to the generation of a mental simulation of alternatives to past factual events, actions, and outcomes. It is a pervasive cognitive feature in everyday life and it is closely related to decision-making, planning, problem-solving, and experience-driven learning-cognitive processes that involve wide neuronal networks in which prefrontal lobes play a fundamental role. Clinical observations in patients with focal prefrontal lobe damage or with neurological and psychiatric diseases related to frontal lobe dysfunction (e.g., Parkinson's disease, Huntington's disease, and schizophrenia) show counterfactual thinking impairments. In this work, we evaluate the performance of CFT in a group of patients with Tourette's syndrome compared with a group of healthy participants. Overall results showed no statistical differences in counterfactual thinking between TS patients and controls in the three counterfactual measures proposed. The possible explanations of this unexpected result are discussed below.