The clinical profile of cerebral small vessel disease: Toward an evidence-based identification of cognitive markers

There is no consensus on which test is more suited to outline the cognitive deficits of cerebral small vessel disease (cSVD) patients. We explored the ability of eight cognitive tests, selected in a previous systematic review as the most commonly used in this population, to differentiate among cSVD patients, controls, and other dementing conditions performing a meta-analysis of 86 studies. We found that cSVD patients performed worse than healthy controls in all tests while data on the comparison to neurodegenerative diseases were limited. We outlined a lack of data on these tests' accuracy on the diagnosis. Cognitive tests measuring processing speed were those mostly associated with neuroimaging cSVD markers. There is currently incomplete evidence that a single test could differentiate cSVD patients with cognitive decline from other dementing diseases. We make preliminary proposals on possible strategies to gain information about the clinical definition of cSVD that currently remains a neuroimaging-based one.

Cortical Thickness Alterations in Chronic Pain Disorder: An Exploratory MRI Study

OBJECTIVE

Chronic pain disorder (CPD) has been associated with brain changes, especially in limbic circuits. However, in most patients with chronic pain, depression or anxiety is a common comorbidity. In this exploratory and naturalistic study, we investigated brain cortical thickness (CTh) differences between patients with CPD and healthy controls, with consideration of concurrent psychiatric symptoms.

METHODS

Twenty-three patients with CPD and 23 age- and sex-matched healthy volunteers were included in this study. CTh was estimated using Freesurfer on high-resolution three-dimensional T1-weighted images acquired with a 3T scanner. Group differences were investigated using an analysis of covariance model that included age, sex, and Beck Depression Inventory I and Trait Anxiety Inventory scores as covariates. The relationship between CTh and Toronto Alexithymia Scale (TAS-20) scores was also investigated in patients. Data were corrected for multiplicity using the False Discovery Rate approach (q < .05).

RESULTS

The comparison between groups using demographics and Beck Depression Inventory I scores as covariates showed thinner cortex in patients compared with controls, after correction for multiplicity in the left precentral (F(1,42) = 21.9, p < .05) and postcentral gyri (F(1,42) = 26.9, p < .05) and in the left inferior temporal sulcus (F(1,42) = 19.6, p < .05). Moreover, using the Trait Anxiety Inventory as covariate, a trend toward significance (p < .001 uncorrected) was seen for the left precentral gyrus (F(1,42) = 13.8), right middle frontal (F(1,42) = 14.3) and inferior parietal gyri (F(1,42) = 13.4), and right anterior temporal pole (F(1,42) = 15.9).

CONCLUSIONS

The results indicate that brain morphological differences between patients with chronic pain disorder and healthy controls are localized to regions that correspond to sensory as well as affective dimensions of pain processing.

Reaction Time is a Marker of Early Cognitive and Behavioral Alterations in Pure Cerebral Small Vessel Disease

BACKGROUND

The assessment of early and subtle cognitive and behavioral effects of cerebral small vessel disease (SVD) requires specific and long-lasting evaluations performed by experienced neuropsychologists. Simpler tools would be helpful for daily clinical practice.

OBJECTIVE

To determine whether a simple reaction time task that lasts 5 minutes and can be performed without external supervision on any tablet or laptop can be used as a proxy of early cognitive and behavioral alterations in CADASIL (Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy), a monogenic form of pure SVD related to NOTCH3 mutations.

METHODS

Twenty-two genetically confirmed patients with CADASIL having preserved global cognitive abilities and without disability (MMSE >24 and modified Rankin's scale ≤1) were compared to 29 age-and-gender matched controls to determine group differences according to: 1) conventional neuropsychological and behavioral testing; 2) a computerized battery evaluating reaction time, processing speed, and executive functions. In a second step, correlations between reaction time and cognitive and behavioral alterations detected using both conventional and computerized testing were tested in patients.

RESULTS

Reaction time was significantly higher in patients than in controls (mean in patients: 283 ms - in controls: 254 ms, p = 0.03). In patients, reaction time was significantly associated with conventional and chronometric tests of executive functions, working memory, and apathy.

CONCLUSION

Reaction time obtained using a very simple task may serve as a proxy of early cognitive and behavioral alterations in SVD and could be easily used in daily clinical practice.

Impairments in Episodic-Autobiographical Memory and Emotional and Social Information Processing in CADASIL during Mid-Adulthood

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) - is the most common genetic source of vascular dementia in adults, being caused by a mutation in NOTCH3 gene. Spontaneous de novo mutations may occur, but their frequency is largely unknown. Ischemic strokes and cognitive impairments are the most frequent manifestations, but seizures affect up to 10% of the patients. Herein, we describe a 47-year-old male scholar with a genetically confirmed diagnosis of CADASIL (Arg133Cys mutation in the NOTCH3 gene) and a seemingly negative family history of CADASIL illness, who was investigated with a comprehensive neuropsychological testing battery and neuroimaging methods. The patient demonstrated on one hand severe and accelerated deteriorations in multiple cognitive domains such as concentration, long-term memory (including the episodic-autobiographical memory domain), problem solving, cognitive flexibility and planning, affect recognition, discrimination and matching, and social cognition (theory of mind). Some of these impairments were even captured by abbreviated instruments for investigating suspicion of dementia. On the other hand the patient still possessed high crystallized (verbal) intelligence and a capacity to put forth a façade of well-preserved intellectual functioning. Although no definite conclusions can be drawn from a single case study, our findings point to the presence of additional cognitive changes in CADASIL in middle adulthood, in particular to impairments in the episodic-autobiographical memory domain and social information processing (e.g., social cognition). Whether these identified impairments are related to the patient's specific phenotype or to an ascertainment bias (e.g., a paucity of studies investigating these cognitive functions) requires elucidation by larger scale research.