Connectivity-based parcellation of the thalamus explains specific cognitive and behavioural symptoms in patients with bilateral thalamic infarct

A novel approach based on diffusion tractography was used here to characterise the cortico-thalamic connectivity in two patients, both presenting with an isolated bilateral infarct in the thalamus, but exhibiting partially different cognitive and behavioural profiles. Both patients (G.P. and R.F.) had a pervasive deficit in episodic memory, but only one of them (R.F.) suffered also from a dysexecutive syndrome. Both patients had an MRI scan at 3T, including a T1-weighted volume. Their lesions were manually segmented. T1-volumes were normalised to standard space, and the same transformations were applied to the lesion masks. Nineteen healthy controls underwent a diffusion-tensor imaging (DTI) scan. Their DTI data were normalised to standard space and averaged. An atlas of Brodmann areas was used to parcellate the prefrontal cortex. Probabilistic tractography was used to assess the probability of connection between each voxel of the thalamus and a set of prefrontal areas. The resulting map of corticothalamic connections was superimposed onto the patients' lesion masks, to assess whether the location of the thalamic lesions in R.F. (but not in G. P.) implied connections with prefrontal areas involved in dysexecutive syndromes. In G.P., the lesion fell within areas of the thalamus poorly connected with prefrontal areas, showing only a modest probability of connection with the anterior cingulate cortex (ACC). Conversely, R.F.'s lesion fell within thalamic areas extensively connected with the ACC bilaterally, with the right dorsolateral prefrontal cortex, and with the left supplementary motor area. Despite a similar, bilateral involvement of the thalamus, the use of connectivity-based segmentation clarified that R.F.'s lesions only were located within nuclei highly connected with the prefrontal cortical areas, thus explaining the patient's frontal syndrome. This study confirms that DTI tractography is a useful tool to examine in vivo the effect of focal lesions on interconnectivity brain patterns

Intentional and automatic measures of specific-category effect in the semantic impairment of patients with Alzheimer's disease

The breakdown of semantic knowledge relative to living and non-living categories was studied in patients with Alzheimer's disease (AD). The same living and non-living items were used in a semantic battery and in a semantic priming paradigm exploring automatic access to the semantic system. Although AD patients showed a semantic deficit on the intentional semantic battery, they demonstrated normal semantic facilitation on the priming task. In the AD group as a whole, the semantic impairment did not preferentially affect the living category either in the intentional or automatic condition. Instead, a prevalent deficit for the living category was found in three AD patients (14% of the group) on the intentional semantic tasks, but not on the automatic one. These findings support the view that the category effect may not be a generalised phenomenon in AD but may be restricted to a limited number of patients. The intentional/automatic dissociation of the semantic breakdown demonstrated by AD patients is discussed in relation to different theories regarding the organisation of semantic memory

Griscelli syndrome type 2: long-term follow-up after unrelated donor bone marrow transplantation

Griscelli syndrome (GS) is a rare autosomal recessive disease characterized by silvery hair ('partial albinism'). Three forms exist; GS type 2 (GS2), the most common one, is characterized by severe primary immunodeficiency with acute episodes of hemophagocytic lymphohistiocytosis (HLH) which may be fatal in the absence of hematopoietic stem cell transplantation. A 5-year-old boy with HLH was referred to us because of silvery-gray hair present since birth. Abnormal pigment clumps were observed in the medulla of hair shafts on light microscopy. Electron microscopy of a skin biopsy revealed melanosomes in melanocytes, but not in keratinocytes. Leukocytes were devoid of intracytoplasmic granules on blood smear. Neurological signs were absent. Genotyping revealed a homozygous haplotype for polymorphic markers linked to the RAB27A locus, but no RAB27A mutation. A diagnosis of GS2 was established. The patient received bone marrow transplantation (BMT) from an unrelated donor, and after 72 months he did not show relapse of HLH. The long, uneventful follow-up supports the use of BMT from an unrelated donor if transplantation from a relative is not possible

A Case of Ketron-Goodman Disease

Pagetoid reticulosis (PR) is a rare form of cutaneous T-cell lymphoma [Mod Pathol 2000;13:502–510]. Two variants of the disease are described: the localized type Woringer-Kolopp disease (WKD) and the disseminated type Ketron-Goodman disease (KGD). KGD may have disseminated lesions, high rate of recurrence and a guarded prognosis [Mod Pathol 2000;13:502–510]. In patients with KGD, therefore, long-term observation is necessary. Disappearance of cutaneous lesions does not mean resolution of the disease [J Am Acad Dermatol 2002;47:183–186]. Herein we report the case of an 84-year-old man with erythematous patches of the trunk and the upper and lower extremities in whom the diagnosis of KGD was made. We describe this case for the rarity of this pathology and for the good response to therapy (IFN)

Wells Syndrome with Multiorgan Involvement Mimicking Hypereosinophilic Syndrome

Eosinophil-associated diseases represent a spectrum of heterogeneous disorders, where blood and cutaneous eosinophilia is the most important feature and eosinophils are the principal cause of cutaneous lesions. These diseases show some similarities in the clinical features but also many distinctive characteristics [Saurat et al., Dermatologia e malattie sessualmente trasmesse, Milano, Masson, 2000]. Wells syndrome is one of these disorders and is an uncommon recurrent inflammatory dermatosis, rarely associated to signs and symptoms of multiple organ involvement [Arch Dermatol 2006;142:1157–1161]. Hypereosinophilic syndrome, in contrast, constitutes a group of idiopathic disorders characterized by blood eosinophilia for at least 6 months, associated with single or multiple organ system dysfunction [Arch Dermatol 2006;142:1157–1161]. Clinically atypical Wells syndrome with multiorgan involvement is reported here. A correct diagnosis is difficult in this case, but clinical and histopathological features are compatible with this diagnosis. The reported condition likely represents a borderline hypereosinophilic disease, in which clinical features of both hypereosinophilic syndrome and Wells syndrome are present

Thalamocortical disconnection affects the somatic marker and social cognition: a case report

Thalamo-cortical connectivity was characterised in a patient with bilateral infarct of the thalami, without evidence of cognitive deficits in everyday life. Patient underwent social and emotional tests, Iowa Gambling Task (IGT), with and without concomitant heart rate variability (HRV) recording and at 3T-MRI to assess thalamo-cortical connectivity. Patient showed impairment at the IGT, in somatic marker, in emotions and theory of mind. MRI documented a bilateral damage of the centromedian-parafascicular complex. Patient's thalamic lesions disconnected brain areas involved in decision-making and autonomic regulation, affecting the somatic marker and resulting in the neuropsychological deficit exhibited by L.C

Automatic memory processes in normal ageing and Alzheimer’s disease

This study examined the contribution of automatic and controlled uses of memory to stem completion in young, middle-aged and older adults, and compared these data with a study involving patients with Alzheimer’s disease (AD) who performed the same task (Hudson and Robertson, 2007). In an inclusion task participants aimed to complete three-letter word stems with a previously studied word, in an exclusion task the aim was to avoid using studied words to complete stems. Performances under inclusion and exclusion conditions were contrasted to obtain estimates of controlled and automatic memory processes using process-dissociation calculations (Jacoby, 1991). An age-related decline, evident from middle age was observed for the estimate of controlled processing, whereas the estimate of automatic processing remained invariant across the age groups. This pattern stands in contrast to what is observed in AD, where both controlled and automatic processes have been shown to be impaired. Therefore, the impairment in memory processing on stem completion that is found in AD is qualitatively different from that observed in normal ageing

Relationships Between Daily Acute Glucose Fluctuations and Cognitive Performance Among Aged Type 2 Diabetic Patients

The mean amplitude of glycemic excursions (MAGE) is a significant deter-minant of overall metabolic control as well as increased risk for diabetes complications. Older individuals with type 2 diabetes are more likely to have moderate cognitive deficits and structural changes in brain tissue. Considering that poor metabolic control is considered a deranging factor for cognitive performance in diabetic patients, we evaluated whether the contributions of MAGE to cognitive status in older patients with type 2 diabetes were independent from the main markers of glycemic control, such as sustained chronic hyperglycemia (A1C), postprandial glycemia (PPG), and fasting plasma glucose (FPG)RESEARCH DESIGN AND METHODS — In 121 older patients with type 2 diabetes, 48-h continuous subcutaneous glucose monitoring (CSGM) were assessed. MAGE and PPG were evaluated during CSGM. The relationship of MAGE to performance on cognitive tests was assessed, with adjustment for age, glycemic control markers, and other determinants of cognitive status. The cognitive tests were a composite score of executive and attention functioning and the Mini Mental Status Examination (MMSE). RESULTS — MAGE was significantly correlated with MMSE (r * 0.83; P * 0.001) and with cognition composite score (r * 0.68; P * 0.001). Moreover, MAGE was associated with the MMSE (P * 0.001) and cognition composite score (P * 0.001) independently of age, sex, BMI, waist-to-hip (WHR) ratio, drug intake, physical activity, mean arterial blood pressure, FPG, PPG, and A1C. CONCLUSIONS — MAGE during a daily period was associated with an impairment of cognitive functioning independent of A1C, FPG, and PPG. The present data suggest that inter-ventional trials in older patients with type 2 diabetes should target not only A1C, PPG, and FPG but also daily acute glucose swing

Exploring the neural and behavioral correlates of cognitive telerehabilitation in mild cognitive impairment with three distinct approaches

Data management: Study data will be recorded in the REDCap database in compliance with the General Data Protection Regulation (GDPR). All participants will be registered with an identification code. The database will be kept updated to reflect the participant’s status at each stage during the course of the study. The collected data, after scientific publication, will be deposited in dedicated repositories according to the good practice of data sharing.Background: Currently, the impact of drug therapies on neurodegenerative conditions is limited. Therefore, there is a strong clinical interest in non-pharmacological interventions aimed at preserving functionality, delaying disease progression, reducing disability, and improving quality of life for both patients and their caregivers. This longitudinal multicenter Randomized Controlled Trial (RCT) applies three innovative cognitive telerehabilitation (TR) methods to evaluate their impact on brain functional connectivity reconfigurations and on the overall level of cognitive and everyday functions. Methods: We will include 110 participants with mild cognitive impairment (MCI). Fifty-five participants will be randomly assigned to the intervention group who will receive cognitive TR via three approaches, namely: (a) Network-based Cognitive Training (NBCT), (b) Home-based Cognitive Rehabilitation (HomeCoRe), or (c) Semantic Memory Rehabilitation Training (SMRT). The control group (n = 55) will receive an unstructured home-based cognitive stimulation. The rehabilitative program will last either 4 (NBTC) or 6 weeks (HomeCoRe and SMRT), and the control condition will be adapted to each TR intervention. The effects of TR will be tested in terms of Δ connectivity change, obtained from high-density electroencephalogram (HD-EEG) or functional magnetic resonance imaging at rest (rs-fMRI), acquired before (T0) and after (T1) the intervention. All participants will undergo a comprehensive neuropsychological assessment at four time-points: baseline (T0), within 2 weeks (T1), and after 6 (T2) and 12 months (T3) from the end of TR. Discussion: The results of this RCT will identify a potential association between improvement in performance induced by individual cognitive TR approaches and modulation of resting-state brain connectivity. The knowledge gained with this study might foster the development of novel TR approaches underpinned by established neural mechanisms to be validated and implemented in clinical practice. Clinical trial registration: [https://classic.clinicaltrials.gov/ct2/show/NCT06278818], identifier [NCT06278818].The author(s) declare that financial support was received for the research, authorship, and/or publication of this article. This study is supported by the Italian Ministry of Health (Ricerca Corrente 2022-2024 - IRCCS Mondino Foundation, Pavia). SC, MM, RM research activities are supported by #NEXTGENERATIONEU (NGEU) and funded by the Ministry of University and Research (MUR), National Recovery and Resilience Plan (NRRP), project MNESYS (PE0000006) a multiscale integrated approach to the study of the nervous system in health and disease (DN. 1553 11.10.2022)

Brain connectivity changes in autosomal recessive Parkinson Disease: a model for the sporadic form

Biallelic genetic mutations in the Park2 and PINK1 genes are frequent causes of autosomal recessive PD. Carriers of single heterozygous mutations may manifest subtle signs of disease, thus providing a unique model of preclinical PD. One emerging hypothesis suggests that non-motor symptom of PD, such as cognitive impairment may be due to a distributed functional disruption of various neuronal circuits. Using resting-state functional MRI (RS-fMRI), we tested the hypothesis that abnormal connectivity within and between brain networks may account for the patients' cognitive status. Eight homozygous and 12 heterozygous carriers of either PINK1 or Park2 mutation and 22 healthy controls underwent RS-fMRI and cognitive assessment. RS-fMRI data underwent independent component analysis to identify five networks of interest: default-mode network, salience network, executive network, right and left fronto-parietal networks. Functional connectivity within and between each network was assessed and compared between groups. All mutation carriers were cognitively impaired, with the homozygous group reporting a more prominent impairment in visuo-spatial working memory. Changes in functional connectivity were evident within all networks between homozygous carriers and controls. Also heterozygotes reported areas of reduced connectivity when compared to controls within two networks. Additionally, increased inter-network connectivity was observed in both groups of mutation carriers, which correlated with their spatial working memory performance, and could thus be interpreted as compensatory. We conclude that both homozygous and heterozygous carriers exhibit pathophysiological changes unveiled by RS-fMRI, which can account for the presence/severity of cognitive symptom