Maura Buttiglione

Hippocampal volume and cortical sources of EEG alpha rhythms in mild cognitive impairment and Alzheimer disease

Atrophy of hippocampus and alteration of resting eyes-closed electroencephalographic (EEG) rhythms represent important features of mild cognitive impairment (MCI) and Alzheimers disease (AD). Here we evaluated linear and non-linear aspects of the relationship between these features in the continuum along MCI and AD conditions, as a reflection of neurodegenerative processes. Eyes-closed resting EEG data were recorded in 60 healthy elderly (Nold), 88 MCI, and 35 Alzheimers disease (AD) patients. Hippocampal volume was measured in magnetic resonance imaging of the MCI and AD subjects. Based on the normalized hippocampal volume, selected MCI subjects could be divided into two demographically paired sub-groups: those with larger hippocampal volume (MCI +h; N=40; mini mental state evaluation - MMSE - score=27.5+/-0.26 SE) and those with smaller hippocampal volume (MCI -h; N=40; h; MMSE=26.5+/-0.34 SE); the normalized hippocampal volume was statistically greater in the MCI +h than in the MCI -h and AD subjects (p<0.0001). 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). Cortical EEG generators were estimated by LORETA software. Results showed that the power of occipital, parietal, and temporal alpha 1 sources was maximum in MCI +h, intermediate in MCI -h, and low in AD patients. Furthermore, the power of these sources was linearly and non-linearly correlated with the normalized hippocampal volume. These 3 EEG sources were given as input for evaluating correlations (linear, exponential, logarithmic and power) with hippocampal volume. When subjects were considered as a unique group, there was a significant linear correlation of hippocampal volume with the magnitude of alpha 1 sources in the parietal, occipital and temporal areas. In general, the EEG sources showing significant linear correlation with hippocampal volume also supported a non-linear correlation with hippocampal volume strongly for the logarithmic one. The present results suggest that progressive atrophy of hippocampus correlates with decreased cortical alpha power, as estimated by using LORETA source modeling, in the continuum along MCI and AD conditions.

Hippocampal, amygdala, and neocortical synchronization of theta rhythms is related to an immediate recall during Rey auditory verbal learning test

It is well known that theta rhythms (3–8 Hz) are the fingerprint of hippocampus, and that neural activity accompanying encoding of words differs according to whether the items are later remembered or forgotten [“subsequent memory effect” (SME)]. Here, we tested the hypothesis that temporal synchronization of theta rhythms among hippocampus, amygdala, and neocortex is related to immediate memorization of repeated words. To address this issue, intracerebral electroencephalographic (EEG) activity was recorded in five subjects with drug‐resistant temporal lobe epilepsy (TLE), under presurgical monitoring routine. During the recording of the intracerebral EEG activity, the subjects performed a computerized version of Rey auditory verbal learning test (RAVLT), a popular test for the clinical evaluation of the immediate and delayed memory. They heard the same list of 15 common words for five times. Each time, immediately after listening the list, the subjects were required to repeat as many words as they could recall. Spectral coherence of the intracerebral EEG activity was computed in order to assess the temporal synchronization of the theta (about 3–8 Hz) rhythms among hippocampus, amygdala, and temporal‐occipital neocortex. We found that theta coherence values between amygdala and hippocampus, and between hippocampus and occipital‐temporal cortex, were higher in amplitude during successful than unsuccessful immediate recall. A control analysis showed that this was true also for a gamma band (40–45 Hz). Furthermore, these theta and gamma effects were not observed in an additional (control) subject with drug‐resistant TLE and a wide lesion to hippocampus. In conclusion, a successful immediate recall to the RAVLT was associated to the enhancement of temporal synchronization of the theta (gamma) rhythms within a cerebral network including hippocampus, amygdala, and temporal–occipital neocortex. Hum Brain Mapp, 2009.

The relationship between group A streptococcal infections and Tourette syndrome: a study on a large service-based cohort

Aim  To evaluate the relationship between diagnosis and clinical course of Tourette syndrome and group A Streptococcus (GAS).

Cortical responses to consciousness of schematic emotional facial expressions: A high‐resolution EEG study

Is conscious perception of emotional face expression related to enhanced cortical responses? Electroencephalographic data (112 channels) were recorded in 15 normal adults during the presentation of cue stimuli with neutral, happy or sad schematic faces (duration: “threshold time” inducing about 50% of correct recognitions), masking stimuli (2 s), and go stimuli with happy or sad schematic faces (0.5 s). The subjects clicked left (right) mouse button in response to go stimuli with happy (sad) faces. After the response, they said “seen” or “not seen” with reference to previous cue stimulus. Electroencephalographic data formed visual event‐related potentials (ERPs). Cortical sources of ERPs were estimated by LORETA software. Reaction time to go stimuli was generally shorter during “seen” than “not seen” trials, possibly due to covert attention and awareness. The cue stimuli evoked four ERP components (posterior N100, N170, P200, and P300), which had similar peak latency in the “not seen” and “seen” ERPs. Only N170 amplitude showed differences in amplitude in the “seen” versus “not seen” ERPs. Compared to the “not seen” ERPs, the “seen” ones showed prefrontal, premotor, and posterior parietal sources of N170 higher in amplitude with the sad cue stimuli and lower in amplitude with the neutral and happy cue stimuli. These results suggest that nonconscious and conscious processing of schematic emotional facial expressions shares a similar temporal evolution of cortical activity, and conscious processing induces an early enhancement of bilateral cortical activity for the schematic sad facial expressions (N170). Hum Brain Mapp, 2010.

Opening/blocking actions of pyruvate kinase antibodies on neuronal and muscular KATP channels

ATP-sensitive-K(+) (KATP) channels couple metabolism to the electrical activity of the cells. This channel is associated with glycolytic enzymes to form complexes regulating the channel activity in various tissues. The pyruvate-kinase (PK) enzyme is an antigen in the Paediatric Autoimmune Neuropsychiatric Disorders Associated Streptococcal infection known as PANDAS which is characterized by an abnormal production of auto-antibodies against PK. Here, the effects of the anti-pyruvate kinase antibody (anti-PK-ab) on the muscle and neuronal KATP channels were investigated in native rat skeletal muscle fibres and human neuroblastoma cell-line (SH-SY5Y), respectively. Furthermore, the interaction of PK with the inwardly rectifier potassium channel (Kir6.1/Kir6.2) subunits of the KATP channels was investigated by co-immunoprecipitation experiments in mouse brain using the anti-PK-ab. Patch-clamp experiments showed that the short-term incubation (1h) of the fibres with the anti-PK-ab at the dilutions of 1:500 and 1:300 enhanced the KATP current of 19.6% and 33.5%, respectively. As opposite, the long-term incubation (24h) of the fibres with the anti-PK-ab at the dilutions of 1:500 and 1:300 reduced the KATP current of 16% and 24%, respectively, reducing the diameter with atrophy. The direct application of the anti-PK-ab to the excised patches in the absence of intracellular ATP caused channel block, while in the presence of nucleotide channel opened. In neuronal cell line, in the short-term the anti-PK-ab potentiated KATP currents without affecting survival, while in the long-term the anti-PK-ab reduced KATP currents inducing neuronal death. Opening/blocking actions of the anti-PK antibodies on the KATP channels were observed, the blocking action causes fibre atrophy and neuronal death. We demonstrated that PK and Kir subunits are physically/functionally coupled in neurons. The KATP/PK complex can be proposed a novel target in the autoimmune diseases associated with anti-PK production as in PANDAS.

Leiter-R versus developmental quotient for estimating cognitive function in preschoolers with pervasive developmental disorders

The utility of the developmental quotient (DQ) obtained with the Psychoeducational Profile Revised (PEP-R) was assessed as a means of estimating cognitive ability in young children with pervasive developmental disorders. Data from the PEP-R were analysed in a sample of 44 children aged from 2.0 to 5.9 years (mean 3.46 ± 1), 13 with an autistic disorder and 31 with a pervasive developmental disorder not otherwise specified. DQ scores were compared with scores from the Leiter International Performance Scale Revised-Visualization and Reasoning Battery (Leiter-R) in the same 44 children. Overall and domain DQs on the PEP-R were significantly correlated with Leiter-R scores. This study suggests that DQ scores obtained from the PEP-R in preschool children with pervasive developmental disorders may be a viable alternative to the Leiter-R as an assessment tool.

Molecular cytogenetic characterization and genotype/phenotype analysis in a patient with a de novo 8p23.2p23.3 deletion/12p13.31p13.33 duplication

Genomic copy number imbalances are being increasingly identified as an important cause of intellectual disability (ID) and behavioral disturbances. This article reports the clinical features, and long term follow‐up of a patient with neurodevelopmental, cognitive, and behavioral abnormalities associated with facial dysmorphism, CNS anomalies, and epilepsy. The karyotype was normal; array CGH testing revealed a de novo cryptic aberration with a terminal 8p23.2p23.3 deletion, and a concomitant 12p13.31p13.33 duplication, of 6.86 Mb, and 8.49 Mb, respectively. Our patient clinical features are compared to those of partial 8 monosomy and/or partial 12p trisomy cases reported in literature, in order to establish genotype–phenotype correlations. For some features, for example, electroencephalogram (EEG) abnormalities and epilepsy, both abnormalities seem to make a contribution, while most phenotypic traits have been assigned to 8p monosomy or to 12p trisomy, contributing to a tentative phenotype map for partial monosomy of the short arm of chromosome 8, and trisomy of the short arm of chromosome 12.

Electrophysiological Study in 2 Children With Transient Hypohidrosis Induced by Topiramate

Objective: Hypohidrosis, often associated with hyperthermia, has been reported, mostly in children, as a rare and reversible adverse effect of topiramate, an anticonvulsant drug with a broad spectrum of antiepileptic activity. The aim of our study is to detect a possible skin innervation involvement asthe mechanism underlying hypohidrosis in children treated with topiramate. Methods: A neurophysiological study has been performed on 2 children who have developed hypohidrosis under topiramate treatment. Electrophysiologicaldata have been recorded during topiramate treatment and compared with a control group. Sympathetic skin responses have been recorded during topiramate assumption and after its discontinuation. Results: In our 2 cases with hypohidrosis related to topiramate, electrophysiological study showed normal function of both beta and delta sensory fibers and absent sympathetic skin responses that recovered to normal after topiramate discontinuation. Conclusions: Our findings confirm that topiramate might induce a transitory specific carbonic anhydrase block at the level of sweat glands, without involvement of peripheral nervous system.

Behçet disease presenting with movement disorders and antibasal ganglia antibodies

We read with interest the paper from Marta M. et al. on “The role of infections in Behçet disease and neuro-Behçet syndrome” [1], aimed to establish if common viral infections could be identified as a precipitant of Behçet disease (BD)with orwithout neurological involvement. As several studies have associated BD with streptococcal infections [2,3], they also explored if anti-basal ganglia antibodies (ABGAs), a type of anti-neuronal antibodies associated with a wide spectrum of post-streptococcal neuropsychiatric disorders [4,5], would be associated with neurological involvement in BD. They did not detect ABGAs in any BD patient. Conversely, herewe describe a BDpatient presenting with chorea and myoclonus, with detectable ABGAs in the serum. This 49-year oldwomanwith longstanding history of frequent headache complained, since age 35, of recurrent episodes of lower limb erythema nodosum and previous records of raised serum antistreptolysin O (ASO) (up to 664 UI/ml; n.v. b200 UI/ml) and anti-DNAse B (up to 400 UI/ml; n.v. b200 UI/ml) antibody titres. Since age 41 she presented with recurrent anterior uveitis, episcleritis, and oral and genital aphthosis. BD was diagnosed and treatment courses of corticosteroids, colchicine and azathioprine were initiated, leading to improvement of aphtosis and erythema. At age 45 she experienced the subacute onset of right arm weakness, which has a self-remitting course with near complete recover in onemonth, and concurrent tremor and involuntary jerks of trunk and limbs. At the age 49 years the patient was referred to our clinic for the persistence of the involuntary movements, despite the absence of systemic manifestations of BD. Neurological examination revealed right-sidedpyramidal signs, bilateral armpostural and rest tremor, more evident on the right, spontaneous and reflex myoclonic jerks, and mild chorea in all four limbs. Laboratory tests revealed persistently increased ASO titre (318 IU/L) and circulating immune complexes (5.6 μg/ml). Cerebrospinal fluid (CSF) analysis and pathergy test were negative. BrainMRI showed bilateral small T2-weighted hyperintensities in the frontal white matter. DaT-SCAN (123I-Ioflupane) SPECT was normal. Levetiracetam 1500 mg/die slightly reduced myoclonic jerks. Given the absence of systemic symptoms the patient refused another course of immunosuppressive

Long-term follow-up of neurological manifestations in a boy with incontinentia pigmenti

Incontinentia pigmenti (IP) is an X-linked dominant genodermatosis confined to females. It is usually lethal in males. However, the survival of some males has been reported in literature. We describe a long follow-up case of a 12-year-old male with IP and a normal karyotype but a genomic deletion of the NEMO gene in the Xq28 position in the form of somatic mosaicism. The patient showed severe ophthalmic abnormalities and neurological manifestations characterised by very mild cerebellar ataxia and a history of epilepsy that was severe at the beginning with West syndrome, become moderate overtime and is now resolved. Despite these neurological manifestations, probably related to the presence of at least some mutated cells in his brain, the long-term follow-up in this patient demonstrated good neurological and cognitive outcome.