Rosa Angela Fabio

Correlations between neurophysiological, behavioral, and cognitive function in Rett syndrome

Rett syndrome, a neurodevelopmental disorder affecting mainly females, is caused by a mutation of the MeCP2 gene. Girls with Rett syndrome manifest diverse behavioral and cognitive phenotypes, and the reasons for this variability remain unknown. In addition, girls with Rett syndrome often have epileptic seizures and abnormal EEGs, the characteristics of which differ with the patient. The aim of the study was to verify if neurophysiological and epileptological characteristics could be correlated with cognitive measures, obtained using eye tracker technology, and behavioral scores (Vineland Adaptive Behavior Scales and Rett Assessment Rating Scale) in 18 patients with Rett syndrome (mean age 13.7 years) at clinical stages III and IV. Age at epilepsy onset and seizure frequency were strictly correlated with neuropsychological outcome, as were EEG stage and distribution of paroxysmal abnormalities. Our findings demonstrate that neurophysiological features should be considered prognostic of cognitive and behavioral outcome in the clinical management of Rett syndrome.

Effects of hypermedia instruction on declarative, conditional and procedural knowledge in ADHD students.

Two groups of students aged between 12 and 14 years--27 with attention deficit/hyperactivity disorder (ADHD) and 28 with both ADHD and learning problems--were compared to a sample of 29 typically developing students in terms of the acquisition and retention of declarative, conditional and procedural knowledge either in a hypermedia learning or in a traditional instructional setting. Hypermedia instruction produced better learning outcomes than traditional instruction did; the benefits concerned prevalently procedural knowledge and emerged mainly in the retention phase. Hypermedia instruction led ADHD students to reach achievement levels similar to those of typically developing students. Furthermore, hypermedia instruction contrasted the decay of knowledge from the acquisition to the retention phase in both clinical groups. On the basis of these findings, hypermedia instruction is proposed as an approach that may help ADHD learners to overcome attention deficits.

Recent insights into genotype-phenotype relationships in patients with Rett syndrome using a fine grain scale

Mutations in MECP2 gene cause Rett syndrome (RTT), a neurodevelopmental disorder affecting around 1 in 10,000 female births. The clinical picture of RTT appears quite heterogeneous for each single feature. Mutations in MECP2 gene have been associated with the onset of RTT. The most known gene function consists of transcriptional repression of specific target genes, mainly by the binding of its methyl binding domain (MBD) to methylated CpG nucleotides and recruiting co-repressors and histone deacetylase binding to DNA by its transcription repressor domain (TRD). This study aimed at evaluating a cohort of 114 Rett syndrome (RTT) patients with a detailed scale measuring the different kinds of impairments produced by the syndrome. The sample included relatively large subsets of the most frequent mutations, so that genotype-phenotype correlations could be tested. Results revealed that frequent missense mutations showed a specific profile in different areas of impairment. The R306C mutation, considered as producing mild impairment, was associated to a moderate phenotype in which behavioural characteristics were mainly affected. A notable difference emerged by comparing mutations truncating the protein before and after the nuclear localization signal; such a difference concerned prevalently the motor-functional and autonomy skills of the patients, affecting the management of everyday activities.

Training communication abilities in Rett Syndrome through reading and writing

The goal of this clinical case study is to investigate the possibility of training communication abilities in people with Rett Syndrome (RS). Usually, girls with RS never exceed the sensorimotor stage of development, but the inter-individual variability typical of RS may lead us to doubt the irrevocability of that developmental limit, especially for those girls who are engaged in cognitive rehabilitation. The case study reported here concerns a 21-year-old girl with RS who was engaged in cognitive rehabilitation training based upon the principles of Feuersteins modificability and mediated learning theory. The training aimed to teach her basic concepts and enhance reading-writing abilities. Statistical analyses showed that the girl reached adequate reading-writing abilities, proving the validity of the cognitive intervention which allowed her to communicate by composing words with her forefinger on an alphabetic table. Although these results need to be cautiously considered as they derive from a single case study, they have implications for future cognitive rehabilitation for deeply impaired clinical conditions as in the case of RS.

Cognitive training modifies frequency EEG bands and neuropsychological measures in Rett syndrome.

Rett syndrome (RS) is a childhood neurodevelopmental disorder characterized by a primary disturbance in neuronal development. Neurological abnormalities in RS are reflected in several behavioral and cognitive impairments such as stereotypies, loss of speech and hand skills, gait apraxia, irregular breathing with hyperventilation while awake, and frequent seizures. Cognitive training can enhance both neuropsychological and neurophysiological parameters. The aim of this study was to investigate whether behaviors and brain activity were modified by training in RS. The modifications were assessed in two phases: (a) after a short-term training (STT) session, i.e., after 30 min of training and (b) after long-term training (LTT), i.e., after 5 days of training. Thirty-four girls with RS were divided into two groups: a training group (21 girls) who underwent the LTT and a control group (13 girls) that did not undergo LTT. The gaze and quantitative EEG (QEEG) data were recorded during the administration of the tasks. A gold-standard eye-tracker and a wearable EEG equipment were used. Results suggest that the participants in the STT task showed a habituation effect, decreased beta activity and increased right asymmetry. The participants in the LTT task looked faster and longer at the target, and show increased beta activity and decreased theta activity, while a leftward asymmetry was re-established. The overall result of this study indicates a positive effect of long-term cognitive training on brain and behavioral parameters in subject with RS.

Autobiographical memory in ADHD subtypes

Abstract Background Episodic autobiographical memory (EAM) has not been extensively investigated in children with attention-deficit/hyperactivity disorder (ADHD). The objective of this study was to examine EAM in school-age children with ADHD in reference to the encoding period: recent memories (previous school years) and remote memories (first years of life). Methods A sample of 29 children with ADHD and 29 typically developing children, matched for age and gender, completed a questionnaire to assess EAM. These participants were recruited from an initial sample of 572 participants. Developmental differences in accessing and recalling specific personal events and episodic details in groups with ADHD were predicted. Results The control group showed a typical trend of EAM with fewer remote and episodic memories than recent ones. The ADHD groups showed a general EAM deficit. More precisely, the ADHD-I group performed equally poorly on remote and recent EAMs, whereas the ADHD-C group showed a higher number of remote EAMs than recent ones. Conclusions The findings suggest that EAM can be impaired in children with ADHD. Clinical and medicolegal implications of these results and the relation between age and childhood amnesia are discussed.

ADHD Auditory and Visual Stimuli in Automatic and Controlled Processes

OBJECTIVE Deficits in ADHD executive function (EF) task have been widely documented in a number of different studies. The aim of this work is to analyze the characteristics of auditory vigilance in ADHD and control subjects in two conditions: with and without interference. METHOD in the first study the Merrills (1992) procedure on automaticity with the dual-task interference paradigm was used; in the second study the auditory test with automatic procedure was used. RESULTS The results of the study confirm that people with ADHD show deficits in auditory vigilance tests and become less careful when interference is introduced. CONCLUSION Results were discussed in terms of a deficit in automaticity process.Objective: Deficits in ADHD executive function (EF) task have been widely documented in a number of different studies. The aim of this work is to analyze the characteristics of auditory vigilance in ADHD and control subjects in two conditions: with and without interference. Method: in the first study the Merrill’s (1992) procedure on automaticity with the dual-task interference paradigm was used; in the second study the auditory test with automatic procedure was used. Results: The results of the study confirm that people with ADHD show deficits in auditory vigilance tests and become less careful when interference is introduced. Conclusion: Results were discussed in terms of a deficit in automaticity process.

Long-term meditation: the relationship between cognitive processes, thinking styles and mindfulness

The aim of this study is to examine the relationship between meditation and cognitive functions. More in depth the purpose is to demonstrate that long-term meditation practice improves attention skills and cognitive flexibility. Eighteen long-term meditation practitioners were compared to a matched control group, who never practiced meditation. Each subject was tested, using computerized software (Presentation Software 9.90), which measured: attention, visual search abilities, working memory and Stroop’s interference tasks. Furthermore, we examined the relationship between long-term meditation practice, mindfulness skills and thinking styles, namely styles of processing information. The results showed significant differences between the two groups, demonstrating that long-term meditation is linked to improvements of attentional functions, working memory and cognitive flexibility.

Neurophysiological and cognitive effects of Transcranial Direct Current Stimulation in three girls with Rett Syndrome with chronic language impairments

BACKGROUND this study was based on both neurophysiological decelerated activity and communication deficits in Rett Syndrome (RTT). AIMS the aim was to examine the neurophysiological and cognitive effects of Transcranial Direct Current Stimulation (tDCS) in three girls with RTT with chronic language impairments. METHODS AND PROCEDURES we proposed an integrated intervention: tDCS and cognitive empowerment applied to language in order to enhance speech production (new functional sounds and new words). Because maximal gains usually are achieved when tDCS is coupled with behavioral training, we applied tDCS stimulation on Brocas area together with linguistic training. OUTCOMES AND RESULTS the results indicated a general enhancement in language abilities (an increase in the number of vowel/consonant sounds and words and the production and comprehension through discrimination), motor coordination (functional movements), and neurophysiological parameters (an increase in the frequency and power of alpha, beta and theta bands). CONCLUSION AND IMPLICATIONS we assume that tDCS stimulation combined with the cognitive empowerment applied to language can significantly influence a chronic impairment even in genetic syndromes. Our results provide data that support the role of tDCS in fostering brain plasticity and in particular in empowering speech production and comprehension in girls with RTT.

The study of automatic and controlled processes in ADHD: a reread and a new proposal

Attention Deficit Hyperactivity Disorder (ADHD) is described as a persistent or an ongoing pattern of inattention and/or hyperactivity-impulsivity that gets in the way of daily life or typical development. Most research in ADHD shows that the core symptoms are related to deficits in executive functions. Only few works show that deficits in ADHD are also related to automatic processes. The shortsightedness of past studies is that they are in focus when looking at the closer object of executive function deficits, but they are out of focus when they fail to include a larger context beyond the focus such as the inextricable relationship between automatic cognitive processes and executive functions deficits. The aim of the present work is to summarize data on automatic and controlled processes in ADHD subjects. Another purpose is to show that the executive functions alone cannot explain the ADHD symptoms, they have be reinterpreted and integrated in the light of new evidence. The new evidence comes from both cognitive and neurophysiological research. Finally, based on new evidences, the Cumulative and Emergent Automatic Deficit model (CEAD) is proposed, its theoretical implications of emerging patterns and key directions for future work are discussed.