Cognition, mood and behavior in CADASIL

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CADASIL is responsible for cognitive, mood or behavior disturbances.

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Cognitive disturbances range from moderate cognitive slowing to impairment of executive functions and may progress to a global decrease of cognitive efficiency up to severe dementia.

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Mood disturbances are extremely variable in intensity, depression is the most frequent symptom.

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Behavioral changes may occur at all stage of the disease, but are often associated with the onset of cognitive alterations. Apathy is the most prominent behavior alteration.

CADASIL is the most common familial cerebral small vessel disease (cSVD). Stereotyped mutations of the NOTCH3 gene are responsible for this archetypal ischemic cSVD that can lead, at the very end stage, to severe dementia. Variable cognitive alterations, mood, or behavior disturbances are frequently observed during the course of the disease. In this review, these clinical manifestations, their occurrence, severity and duration are analyzed in relation to the disease progression. Also, the potential relationships with cerebral lesions and treatment options are discussed.

Altered Regional Brain Homogeneity of BOLD Signal in CADASIL: A Resting State fMRI Study

BACKGROUND AND PURPOSE

The cognitive decline in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is assumed to be due to a cortical-subcortical disconnection secondary to damage to the cerebral white matter (WM). Using resting state functional MRI (rsfMRI) and analysis of the regional homogeneity (ReHo), we examined a group of CADASIL patients and a group of healthy subjects in order to: (1) explore possible differences between the two groups; and (2) to assess, in CADASIL patients, whether any ReHo abnormalities correlate with individual burdens of WM T₂ -weighted hyperintensity and diffusion tensor imaging (DTI)-derived index of mean diffusivity (MD) of the cerebral WM, an index reflecting microstructural damage in CADASIL.

METHODS

Twenty-three paucisymptomatic CADASIL patients (13 females; age mean ± standard deviation = 43.6 ± 11.1 years; three symptomatic and 20 with no or few symptoms) and 16 healthy controls (nine females; age 46.6 ± 11.0 years) were examined with T₁ -weighted, T₂ -weighted fluid attenuated inversion recovery images, DTI, and rsfMRI.

RESULTS

When compared to controls, CADASIL patients showed four clusters of significantly lower ReHo values in cortical areas belonging to networks involved in inhibition and attention, including the right insula, the left superior frontal gyrus, and the bilateral anterior cingulated cortex. ReHo changes did not correlate with an individual patient's lesion burden or MD.

CONCLUSIONS

This study reveals decreased ReHo of rsfMRI signals in cortical areas involved in inhibition and attention processes, suggesting a potential role for these functional cortical changes in CADASIL.

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.