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A large non-Jewish Italian family affected by idiopathic torsion dystonia with autosomal dominant transmission and almost complete penetrance is reported. The prevalent phenotype was characterised by early onset with cranial-cervical involvement and progression to a segmental distribution; progression to generalisation was also found. Among 45 people examined, 14 were considered definitely or probably affected by idiopathic torsion dystonia. Eight definitely affected members had mean age (SD) at onset of 15.6 (12.5); idiopathic torsion dystonia started in the cranial-cervical region in six of them, in the upper limbs in two; in four cases dystonia progressed to other body regions, in two cases a generalisation was seen. Linkage analysis with 9q34 markers excluded the region containing the DYT1 locus in this family; linkage to the dopa-responsive dystonia markers was also excluded. A comparison of the phenotype in the present family and other non-DYT1 families shows striking overlapping features differing from those of DYT1 idiopathic torsion dystonia. [ABSTRACT FROM AUTHOR]

The study aimed at mapping (i) the distributed alpha (8–13 Hz) electroencephalography (EEG) sources specific for mild Alzheimer''s disease (AD) compared with vascular dementia (VaD) in normal, elderly people (Nold) and (ii) the distributed alpha EEG sources sensitive to mild AD at different stages of severity. Resting EEG (10–20 electrode montage) was recorded from 48 mild AD, 20 VaD and 38 Nold subjects. Both AD and VaD patients had 24–17 on their mini mental state examinations (MMSE). Alpha bands were subdivided in alpha 1 (8–10.5 Hz) and alpha 2 (10.5–13 Hz) subbands. Cortical alpha EEG sources were modeled by “low resolution brain electromagnetic tomography” (LORETA). Regarding issue (i), there was a decline of central, parietal, temporal and limbic alpha 1 sources specific to the mild AD group with respect to Nold and VaD groups. On the other hand, occipital alpha 1 sources showed a strong decline in mild AD compared with the VaD group. However, this finding was “unspecific” because a certain decline of these sources was also recognized in VaD compared with Nold. Regarding issue (ii), there was a lower power of occipital alpha 1 sources in the mild AD more severely diseased subgroup. On the whole, these findings stress the reliability of modern technologies for EEG analysis as the LORETA approach to the study of cortical rhythmicity in resting mild AD. [Copyright &y& Elsevier]

Highlights: [•] Through an ad hoc procedure (FSS), distinct sources were identified in S1 and M1. [•] No differences were found between spectral properties of patients and controls for either S1 and M1. [•] Gamma band S1–M1 coherence was bilaterally reduced in patients during movement. [•] In focal hand dystonia, uncoupling replaces the physiological sensorimotor coupling. [•] Bi-hemispheric abnormalities in unilateral dystonia suggest endophenotypic traits. [ABSTRACT FROM AUTHOR]

Abstract: To obtain a direct sensorimotor integration assessment in primary hand cortical areas (M1) of patients suffering from focal task-specific hand dystonia, magnetoencephalographic (MEG) and opponens pollicis electromyographic (EMG) activities were acquired during a motor task expressly chosen not to induce dystonic movements in our patients, to disentangle abnormalities indicating a possible substrate on which dystonia develops. A simple isometric contraction was performed either alone or in combination with median nerve stimulation, i.e. when a non-physiological sensory inflow was overlapping with the physiological feedback. As control condition, median nerve stimulation was also performed at rest. The task was performed bilaterally both in eight patients and in 16 healthy volunteers. In comparison with results in controls we found that in dystonic patients: i) MEG-EMG coherence was higher; ii) it reduced much less during galvanic stimulation in the hemisphere contralateral to the dystonic arm, simultaneously with iii) stronger inhibition of the sensory areas responsiveness due to movement; iv) the cortical component including contributions from sensory inhibitory and motor structures was reduced and v) much more inhibited during movement. It is documented that a simultaneous cortico-muscular coherence increase occurs in presence of a reduced M1 responsiveness to the inflow from the sensory regions. This could indicate an unbalance of the fronto-parietal functional impact on M1, with a weakening of the parietal components. Concurrently, signs of a less differentiated sensory hand representation—possibly due to impaired inhibitory mechanisms efficiency—and signs of a reduced repertoire of voluntary motor control strategies were found. [Copyright &y& Elsevier]

Abstract: High plasma concentration of homocysteine is an independent risk factor for Alzheimer’s disease (AD), due to microvascular impairment and consequent neural loss [ Plasma homocysteine as a risk factor for dementia and Alzheimer’s disease. N Engl J Med 346(7):476–483]. Is high plasma homocysteine level related to slow electroencephalographic (EEG) rhythms in awake resting AD subjects, as a reflection of known relationships between cortical neural loss and these rhythms? To test this hypothesis, we enrolled 34 mild AD patients and 34 subjects with mild cognitive impairment (MCI). Enrolled people were then subdivided into four sub-groups of 17 persons: MCI and AD subjects with low homocysteine level (MCI− and AD−, homocysteine level <11 μmol/l); MCI and AD subjects with high homocysteine level (MCI+ and AD+, homocysteine level ≥11 μmol/l). Resting eyes-closed EEG data were recorded. EEG rhythms of interest were delta (2–4 Hz), theta (4–8 Hz), alpha 1 (8–10.5 Hz), alpha 2 (10.5–13 Hz), beta 1 (13–20 Hz), and beta 2 (20–30 Hz). EEG cortical sources were estimated by low-resolution brain electromagnetic tomography (LORETA). Results showed that delta (frontal and temporal), theta (central, frontal, parietal, occipital, and temporal), alpha 1 (parietal, occipital, and temporal), and alpha 2 (parietal and occipital) sources were stronger in magnitude in AD+ than AD− group. Instead, no difference was found between MCI− and MCI+ groups. In conclusion, high plasma homocysteine level is related to unselective increment of cortical delta, theta, and alpha rhythms in mild AD, thus unveiling possible relationships among that level, microvascular concomitants of advanced neurodegenerative processes, and synchronization mechanisms generating EEG rhythms. [Copyright &y& Elsevier]

Abstract: Objective. Can quantitative electroencephalography (EEG) predict the conversion from mild cognitive impairment (MCI) to Alzheimer’s disease (AD)? Methods. Sixty-nine subjects fulfilling criteria for MCI were enrolled; cortical connectivity (spectral coherence) and (low resolution brain electromagnetic tomography) sources of EEG rhythms (δ=2–4 Hz; θ=4–8 Hz; α 1=8–10.5 Hz; α 2=10.5–13 Hz: β 1=13–20 Hz; β 2=20–30 Hz; and γ=30–40) were evaluated at baseline (time of MCI diagnosis) and follow up (about 14 months later). At follow-up, 45 subjects were still MCI (MCI Stable) and 24 subjects were converted to AD (MCI Converted). Results. At baseline, fronto-parietal midline coherence as well as δ (temporal), θ (parietal, occipital and temporal), and α 1 (central, parietal, occipital, temporal, limbic) sources were stronger in MCI Converted than stable subjects (P<0.05). Cox regression modeling showed low midline coherence and weak temporal source associated with 10% annual rate AD conversion, while this rate increased up to 40% and 60% when strong temporal δ source and high midline γ coherence were observed respectively. Interpretation. Low-cost and diffuse computerized EEG techniques are able to statistically predict MCI to AD conversion. [Copyright &y& Elsevier]

Abstract: Movement control requires continuous and reciprocal exchange of information between activities of motor areas involved in the task program execution and those elaborating proprioceptive sensory information. Our aim was to investigate the sensorimotor interactions in the region dedicated to hand control in healthy humans, focusing onto primary sensory and motor cortices, by selecting the time window at very early latencies. Through magnetoencephalographic recordings, we obtained a simultaneous assessment of sensory cortex activity modulation due to movement and of motor cortex activity modulation due to sensory stimulation, by eliciting a galvanic stimulation to the nerve (the median nerve) innervating a muscle (the opponens pollicis), at rest or during voluntary contraction. The primary sensory and motor cortices activities were investigated respectively through excitability in response to sensory stimulation and the cortico-muscular coherence. The task was performed bilaterally. A clear reduction of the cortico-muscular coherence was found in the short time window following stimuli (between around 150–450 ms). In the same time period, the motor control of isometric contraction was preserved. This could suggest that cortical component of voluntary movement control was transiently mediated by neuronal firing rate tuning more than by cortico-muscular synchronization. In addition to the known primary sensory cortex inhibition due to movement, a more evident reduction was found for the component known to include a contribution from primary motor areas. Gating effects were lower in the dominant left hemisphere, suggesting that sensorimotor areas dominant for hand control benefit of narrowing down gating effects. [Copyright &y& Elsevier]