Familial Alzheimer's disease associated with heterozygous NPC1 mutation.

INTRODUCTION: NPC1 mutations are responsible for Niemann-Pick disease type C (NPC), a rare autosomal recessive neurodegenerative disease. Patients harbouring heterozygous NPC1 mutations may rarely show parkinsonism or dementia. Here, we describe for the first time a large family with an apparently autosomal dominant late-onset Alzheimer's disease (AD) harbouring a novel heterozygous NPC1 mutation. METHODS: All the five living siblings belonging to the family were evaluated. We performed clinical evaluation, neuropsychological tests, assessment of cerebrospinal fluid markers of amyloid deposition, tau pathology and neurodegeneration (ATN), structural neuroimaging and brain amyloid-positron emission tomography. Oxysterol serum levels were also tested. A wide next-generation sequencing panel of genes associated with neurodegenerative diseases and a whole exome sequencing analysis were performed. RESULTS: We detected the novel heterozygous c.3034G>T (p.Gly1012Cys) mutation in NPC1, shared by all the siblings. No other point mutations or deletions in NPC1 or NPC2 were found. In four siblings, a diagnosis of late-onset AD was defined according to clinical characterisation and ATN biomarkers (A+, T+, N+) and serum oxysterol analysis showed increased 7-ketocholesterol and cholestane-3ß,5α,6ß-triol. DISCUSSION: We describe a novel NPC1 heterozygous mutation harboured by different members of a family with autosomal dominant late-onset amnesic AD without NPC-associated features. A missense mutation in homozygous state in the same aminoacidic position has been previously reported in a patient with NPC with severe phenotype. The alteration of serum oxysterols in our family corroborates the pathogenic role of our NPC1 mutation. Our work, illustrating clinical and biochemical disease hallmarks associated with NPC1 heterozygosity in patients affected by AD, provides relevant insights into the pathogenetic mechanisms underlying this possible novel association.

Different saccadic profile in bulbar versus spinal-onset amyotrophic lateral sclerosis.

Two clinical phenotypes characterize the onset of amyotrophic lateral sclerosis (ALS): the spinal variant, with symptoms beginning in the limbs, and the bulbar variant, affecting firstly speech and swallowing. The two variants show some distinct features in the histopathology, localization and prognosis, but to which extent they really differ clinically and pathologically remains to be clarified. Recent neuropathological and neuroimaging studies have suggested a broader spreading of the neurodegenerative process in ALS, extending beyond the motor areas, toward other cortical and deep grey matter regions, many of which are involved in visual processing and saccadic control. Indeed, a wide range of eye movement deficits have been reported in ALS, but they have never been used to distinguish the two ALS variants. Since quantifying eye movements is a very sensitive and specific method for the study of brain networks, we compared different saccadic and visual search behaviours across spinal ALS patients (n = 12), bulbar ALS patients (n = 6) and healthy control subjects (n = 13), along with cognitive and MRI measures, with the aim to define more accurately the two patients subgroups and possibly clarify a different underlying neural impairment. We found separate profiles of visually-guided saccades between spinal (short saccades) and bulbar (slow saccades) ALS, which could result from the pathologic involvement of different pathways. We suggest an early involvement of the parieto-collicular-cerebellar network in spinal ALS and the fronto-brainstem circuit in bulbar ALS. Overall, our data confirm the diagnostic value of the eye movements analysis in ALS and add new insight on the involved neural networks.

Diversified social cognition in temporal lobe epilepsy.

OBJECTIVES: In an integrated model of social cognition (SC), the theory of mind (ToM), the recognition of behavior in social situations (RBSS), empathy, and sensitivity to moral and conventional rules (SMCR) cooperate in generating mental representations of the interpersonal relationships. The aim of this study was to extend our knowledge of the SC of temporal lobe epilepsy (TLE) patients by characterizing its various aspects and predictors. MATERIALS AND METHODS: Fifty adult patients with TLE and 50 healthy controls were assessed using ToM, RBSS and SMCR neuropsychological tests, the Empathy Questionnaire, and the psychopathology Symptoms Check List 90R (SCL90-R). RESULTS: Patients and controls were similar in terms of occupation, income level, age, sex, marital status and the number of family members. Multivariate analysis of variance with demographic variables as the covariates showed that they were similar in SMCR and empathy. The patients, conversely, had lower ToM and RBSS scores, and higher scores on the SCL90-R psychoticism, depression, paranoid ideation, obsessive-compulsive, somatization and anxiety scales. Impaired RBSS was predicted by psychopathological symptoms, income level, schooling and the duration of epilepsy; ToM related to TLE laterality, seizure frequency and epilepsy duration. CONCLUSIONS: In adult patients with TLE, SC is simultaneously partially impaired and partially preserved, and the fact this is associated with clinical, demographic and psychological variables suggests that SC depends on the integrity of the temporal lobe and the interconnected brain regions, as well as psychosocial stimuli. This approach may contribute to clarify the neurobehavioural phenotype of TLE.

Functional and Brain Activation Changes Following Specialized Upper-Limb Exercise in Parkinson's Disease.

For the management of Parkinson's disease (PD), the concept of forced exercise (FE) has drawn interest. In PD subjects, the FE executed with lower limbs has been shown to lessen symptoms and to promote brain adaptive changes. Our study is aimed to investigate the effect of an upper-limb exercise, conceptually comparable with the FE, in PD. Upper-limb exercise was achieved in a sitting position by using a specially designed device (Angel's Wings®). Clinical data, computerized dynamic posturography, magnetic resonance imaging (MRI) (resting-state MRI and arterial spin labeling), and neuropsychological tests were used before and after 2 months' exercise training. We found a significant long-lasting improvement in Unified Parkinson Disease Rating Scale (UPDRS)-III and cognitive scales, along with improvement in balance and postural control (better alignment of the gravity center and improvement in weight symmetry and in anticipatory motor strategies). Computerized dynamic posturography pointed out an enhanced central ability to integrate the vestibular signals with afferents from other sensory systems. Neuroimaging analyses after 2 months' exercise training showed, with respect to pretraining condition, many changes. An increase of the cerebral blood flow was evident in the left primary motor cortex (M1), left supplementary motor cortical area, and left cerebellar cortex. The bilateral globus pallidus showed an increased functional connectivity to the right central operculum, right posterior cingulate gyrus, and left sensorimotor cortex. Seed-to-voxel analysis demonstrated a functional connectivity between M1 and the left superior frontal gyrus. Left crus II showed strengthened connections with the left pre-rolandic area, left post-rolandic area, and left supramarginal area. These findings likely reflect compensatory mechanisms to the neuropathological hallmark of PD. Overall, our results show that this upper-limb exercise model, conceptually comparable with the FE already tested in the lower limbs, leads to a global improvement (involving non-exercised limbs) likely consistent with the functional changes observed in the central nervous system.

Clinical course of two Italian siblings with ataxia-telangiectasia-like disorder.

Ataxia-telangiectasia-like disorder (ATLD) due to mutations in the MRE11 gene is a very rare autosomal recessive disease, described so far in only 20 patients. Little is known about the onset of the first symptoms or the clinical course of the disease. The present report contributes to the diagnosis of ATLD and its prognosis at onset. We report 30 years of clinical and ophthalmic observations and the results of quantitative magnetic resonance (MR), MR spectroscopy (proton magnetic resonance spectroscopic imaging) and neuropsychological assessment in the first Italian siblings identified with ATLD. Although the disease had early onset and the clinical picture was initially severe, suggesting ataxia-telangiectasia, neurological impairment, ocular motor apraxia and neuropsychological tests showed very slow deterioration in adult age. The patients developed eye and head motor strategies to compensate ocular motor apraxia. MR measurements and MR spectroscopy disclosed widespread neuronal and axonal involvement. ATLD should be considered in patients with ocular apraxia and ataxia in infancy. The long follow-up provided insights into clinical outcome, with functional neuroimaging studies shedding light on the pathogenetic mechanisms of this rare disease.

EEG features and epilepsy in MECP2-mutated patients with the Zappella variant of Rett syndrome.

OBJECTIVE: To assess the presence/absence of peculiar EEG features and epilepsy in MECP2-mutated Rett patients with the Zappella-Rett variant (Z-RTT) also known as preserved speech variant. METHODS: Retrospective analysis of 16 (age 19.4+/-8.4years; range 8-38years) MECP2 mutated Z-RTT cases, including 11 high or intermediate performance (HIP), and five low-performance (LP) patients was performed. Peculiar EEG features were analyzed as a function of the HIP or LP Z-RTT categories: (1) centro-temporal spikes, (2) multifocal EEG activity, (3) EEG encephalopathy (i.e. multifocal EEG activity associated with the presence of background slowing and diffuse slow activity), (4) spindles and K-complex. Furthermore, we assessed the occurrence of epilepsy. Correlations between electroclinical features and category of Z-RTT genotype (missense or truncation mutation) were also tested. RESULTS: The Z-RTT HIP group showed a very abnormal EEG (presence of centro-temporal spikes: p=0.004808), although the cases studied were not epileptogenic and did not develop encephalopathy. The LP group showed multifocal EEG activity (p=0.000229), EEG encephalopathy (p=0.000229) and epilepsy (p=0.299451). No significant differences between the prevalence of centro-temporal spikes, multifocal EEG activity, EEG encephalopathy, and epilepsy between the patients with the truncation or missense mutation were observed. CONCLUSIONS: EEG electrophysiological patterns and epileptogenic susceptibility differ in Z-RTT according to the level of performance (i.e. HIP or LP). SIGNIFICANCE: These results indicate that HIP and LP Z-RTT should be considered as distinct entities, not only on a clinical basis, but also as it concerns EEG features and epileptogenic susceptibility. These results could offer support in the practical management of patients and family counseling.