Executive function and intellectual disability: innovations, methods and treatment.

This editorial presents an introduction to and an overview of the current JIDR special issue on "Executive Function in Intellectual Disability." The articles included in this special issue provide a contemporary, in depth exploration of questions regarding the nature of EF in individuals with ID. Topics include the emergence of EF during early childhood in ID-related conditions, the influence of EF on other domains of development, and the relationship between EF and adaptation throughout the lifespan. This editorial synthesizes the findings presented in this special issue and identifies methodological challenges that researchers will continue to face in future investigations of this important area.

Developmental trajectories of spatial-sequential and spatial-simultaneous working memory in Down syndrome.

BACKGROUND: Working memory (WM) is generally considered an area of weakness in the cognitive profile associated with Down syndrome (DS). The great majority of studies explored WM in this population through a comparison with typical development (TD) on the basis of mental age or developmental level. However, it is also relevant to understand how these skills develop and whether such development could be more related to chronological or developmental level. In the present study, we explored cross-sectional developmental trajectories of spatial-sequential and spatial-simultaneous WM in individuals with DS across chronological age and developmental level. Typically developing children (TD) of similar mental age were also included as a comparison group. METHODS: Eighty-four individuals with DS (aged between 7 and 30 years) and 327 children with TD (aged between 4 and 8 years) were administered with tasks to assess spatial-sequential and spatial-simultaneous WM, together with tasks to assess both general verbal and spatial developmental levels. RESULTS AND CONCLUSION: Performance in spatial-simultaneous WM task was lower compared with spatial-sequential WM task in both groups. In the case of individuals with DS, the developmental trajectories of chronological age are better described through a segmented model showing increased performance until approximately 13 years of age, followed by a rather flat progress. In the case of TD children, developmental trajectories are better described through a linear model in the spatial-simultaneous WM task when chronological age is considered; in the spatial-sequential WM, the increase in performance with age was however characterised by a discontinuity at age 6. The increase in performance followed a linear pattern in both groups (DS and TD) without substantial differences between the types of measure used (verbal vs. spatial) when the developmental level is considered.

Executive functions and adaptive behaviour in individuals with Down syndrome.

BACKGROUND: Previous research has explored executive functions (EFs) and adaptive behaviour in children and adolescents with Down syndrome (DS), but there is a paucity of research on the relationship between the two in this population. This study aims to shed light on the profile of EFs and adaptive behaviour in DS, exploring the differences by age and investigating the relationship between these two domains. METHOD: Parents/caregivers of 100 individuals with DS from 3 to 16 years old participated in the study. The sample was divided into preschoolers (3-6.11 years old) and school-age children (7-16 years old). Parents/caregivers completed either the Preschool Version of the Behaviour Rating Inventory of Executive Function (for children 2-6.11 years old) or the Second Edition of the same Inventory (for individuals 7 + years old). Adaptive behaviour was assessed with the Vineland Adaptive Behaviour Scale - Interview, Second Edition. RESULTS: Findings suggest that individuals with DS have overall difficulties, but also patterns of strength and weakness in their EFs and adaptive behaviour. The preschool-age and school-age children's EF profiles differed slightly. While both age groups showed Emotional Control as a relative strength and Working Memory as a weakness, the school-age group revealed further weaknesses in Shift and Plan/Organise. As concerns adaptive behaviour, the profiles were similar in the two age groups, with Socialisation as a strength, and Communication and Daily Living Skills as weaknesses, but with a tendency for preschoolers to obtain intermediate scores for the latter. When the relationship between EFs and adaptive behaviour was explored, Working Memory predicted Communication in the younger group, while in the older group the predictors varied, depending on the adaptive domains: Working Memory was a predictor of Communication, Inhibit of Daily Living Skills, and Inhibit and Shift of Socialisation. CONCLUSION: As well as elucidating the EF profiles and adaptive behaviour in individuals with DS by age, this study points to the role of EFs in adaptive functioning, providing important information for targeted interventions.

Environment learning from virtual exploration in individuals with down syndrome: the role of perspective and sketch maps.

BACKGROUND: Spatial knowledge about an environment is an important determinant of ability to move effectively within it and of personal autonomy. Individuals with Down's syndrome (DS) have difficulty managing configural visuospatial information. METHOD: Twenty-nine individuals with DS and 29 typically developing (TD) children, matched for mental age, learned about environments through virtual exploration using a route or survey view. A sketch map of the environment was or was not presented before exploration. Then the acquisition of configural knowledge (landmark locations) and route retracing were tested. RESULTS: Individuals with DS were able to acquire configural knowledge through virtual exploration in all presentation conditions, and generally performed no worse than matched TD children. However, they were not able to benefit from the conditions that facilitated acquisition of configural knowledge in TD children, that is, seeing a sketch map before exploring and exploring in survey (rather than route) view. As regards route retracing, individuals with DS paused more often than controls and tended to travel longer paths, which made them slower overall. CONCLUSIONS: DS reduces children's ability to benefit from additional survey information and may be related to difficulty in elaborating configural/simultaneous information.

Working memory in Down syndrome: is there a dual task deficit?

BACKGROUND: Recent studies have shown that individuals with Down syndrome (DS) are poorer than controls in performing verbal and visuospatial dual tasks. The present study aims at better investigating the dual task deficit in working memory in individuals with DS. METHOD: Forty-five individuals with DS and 45 typically developing children matched for verbal mental age completed a series of verbal and visuospatial working memory tasks, involving conditions that either required the combination of two tasks in the same modality (verbal or visual) or of cross-modality pairs of tasks. RESULTS AND CONCLUSIONS: Two distinct deficits were found in individuals with DS: impairment in verbal tasks and further impairment in all dual task conditions. The results confirm the hypothesis of a central executive impairment in individuals with DS.

The effect of configuration on VSWM performance of Down syndrome individuals.

BACKGROUND: Recent studies have demonstrated that individuals with Down syndrome (DS) are poorer than controls in spatial-simultaneous tasks, but not in spatial-sequential tasks. To explain this finding, it has been suggested that the simultaneous visuo-spatial working memory deficit of individuals with DS could be due to the request for processing more than one item at a time. The present study examines the possibility of reducing the difficulties encountered by DS individuals on spatial-simultaneous tasks by proposing a task that uses structured material. METHOD: Two tasks were administered to 20 children and adolescents with DS, and 20 controls matched for verbal mental age. The tasks involved memorising and recalling filled-cell positions in a series of matrices in which an increasing number of cells (1-7) were filled. In the structured condition the filled cells were displayed to form a pattern, whereas in the random condition they were randomly arranged. RESULTS AND CONCLUSIONS: Results showed that individuals with DS are able to take advantage of structured material for raising their performance, but to a less extent than typically developing children.

Executive function in adolescents with Down Syndrome.

BACKGROUND: The present work is aimed at analysing executive function (EF) in adolescents with Down Syndrome (DS). So far, EF has been analysed mainly in adults with DS, showing a pattern of impairment. However, less is known about children and adolescents with this syndrome. Studying adolescents with DS might help us better understand whether performances on EF tasks of individuals with DS are determined by age or by Alzheimer disease, as some studies suggest, or whether their performances are directly related to DS cognitive profile. METHOD: A battery of EF tasks assessing set shifting, planning/problem-solving, working memory, inhibition/perseveration and fluency, as well as a tasks assessing sustained attention has been administered to a group of 15 adolescents with DS and 15 typically developing children matched for mental age. All EF tasks were selected from previous studies with individuals with intellectual disabilities or from developmental literature and are thought to be useful for the samples considered. RESULTS: The present results revealed that the group of individuals with DS performed at a significantly lower level on tasks assessing set shifting, planning/problem-solving, working memory and inhibition/perseveration, but not on the tasks assessing fluency. In addition, individuals with DS demonstrated a greater number of errors and less strategy use for the sustained attention task. CONCLUSIONS: The results suggest a broad impairment in EF in adolescents with DS, and are consistent with several similar studies conducted with adults with DS. We assume that EF deficit is a characteristic of DS.

A specific deficit in visuospatial simultaneous working memory in Down syndrome.

BACKGROUND: Recent studies have demonstrated that individuals with Down syndrome (DS) present both central and verbal working memory deficits compared with controls matched for mental age, whereas evidence on visuospatial working memory (VSWM) has remained ambiguous. The present paper uses a battery of VSWM tasks to test the hypothesis that individuals with DS can also encounter specific difficulties in VSWM. METHOD: Four tasks were administered to 34 children and adolescents with DS and 34 controls matched for verbal mental age. In two of these tasks, participants had to remember a series of locations sequentially presented on a matrix (spatial-sequential WM); in another two, they had to remember locations simultaneously presented (spatial-simultaneous WM). RESULTS AND CONCLUSIONS: Results showed that individuals with DS are poorer than controls in the spatial-simultaneous tasks, but not in the spatial-sequential tasks. These findings were not due to a difference in speed of visuospatial processing. In fact, when performances of the two groups in VSWM were compared using speed measures as covariates, differences between groups remained. It is suggested that the simultaneous VSWM deficit of individuals with DS could be due to the request for processing more than one item at a time.

Effectiveness of ibuprofen-arginine in the treatment of acute migraine attacks.

The purpose of this study was to evaluate the effectiveness of a new formulation of ibuprofen (ibuprofen-arginine [IA]) in the treatment of migraine attacks. This is a faster absorbed formulation as compared with ibuprofen alone. The rapidity of action is considered to be a crucial factor in the treatment of migraine attacks. Forty migraine patients participated in this multicenter, double-blind, crossover, randomized, placebo-controlled trial. Each patient was treated with a single oral dose of IA 400 mg or placebo during two consecutive migraine attacks. The results confirm the efficacy of IA, with a significant (p < 0.05) improvement in pain relief at 30 min after treatment. A statistically significant (p < 0.001) reduction in pain intensity was observed at 1, 2, 4 and 6 h after treatment with ibuprofen as compared with placebo. IA was well tolerated and our data indicate that this new formulation of ibuprofen is valuable in the treatment of acute migraine attacks.

[Pathogenesis of tension headache: role of temporomandibular disorders. A research protocol]. / La patogenesi delle cefalee di tipo tensivo: ruolo dei disordini cranio-cervico-mandibolari. Protocollo di ricerca.

BACKGROUND: The purpose of this research is to verify through a blind, controlled study if there is a positive correlation between tension-type headache and the most likely causative factors. In accordance with the headache classification of the international headache society, they are: oro-mandibular dysfunction; psychosocial stress; anxiety; depression; headache as a delusion or an idea; muscular stress; drug overuse for tension-type headaches. METHODS: The subjects who participated in the study were selected from patients diagnosed as having tension-type headache. The patients were of both sexes and aged between 18 and 60 years. A control subject was joined to every case. 102 subjects entered the study. The protocol includes the following examinations: questionnaire about the headache's characteristics; questionnaire about muscular stress; questionnaire about sleep; physiologic and pathologic history; structured Clinical Interview for DSMIII-R (Diagnostic and Statistical Manual of Mental Disorders) for diagnosis of anxiety, depression and somatoform disorder; DSMIII-R questionnaire about psychosocial stressors; EMG; algometry; evaluation of the TMJ; evaluation of the muscles of mastication; evaluation of the denture. RESULTS AND CONCLUSIONS: A positive correlations between oro-mandibular dysfunction, anxiety, muscular stress and tension-type headache was found.

Posterior headache as a warning symptom of vertebral dissection: a case report.

Cervicocerebral arterial dissection is an important cause of stroke in young adults; the onset is often characterised by severe occipital headache, followed by nausea, vomiting and vertigo, mimicking a migraine attack. We describe herewith a case of vertebral arterial dissection with cerebellar infarction, which started with a posterior headache and neurovegetative symptoms, without other signs. Recommendations for recognition of similar cases, potentially dangerous and treatable, are discussed.

Asymmetrical reduction of the nociceptive flexion reflex threshold in cluster headache.

The nociceptive flexion reflex (NFR) of the lower limbs (RIII reflex) was examined bilaterally in 54 cluster headache (CH) patients suffering from episodic CH (ECH) and chronic CH (CCH). Fifteen ECH patients were examined in both remission and active phases. The RIII reflex threshold (Tr) and the threshold of pain sensation (Tp) were significantly reduced on the symptomatic side in patients with episodic CH during the bout. During the active phase of episodic CH an inverse correlation was found between the severity of CH (ratio: number of cluster periods/years of illness duration) and the Tp, which may suggest a role for secondary central sensitization in pain pathways. The lower Tr and Tp on the symptomatic side is in keeping with previous observations exploring pain mechanisms using different methods (i.e. corneal reflex, pain pressure threshold). On the whole, these data tie in with the view of an impairment of the pain control system, which parallels the periodicity of the disorder in the episodic form.

3D kinematic analysis and clinical evaluation of neck movements in patients with whiplash injury.

In recent decades whiplash injuries, being a major reason for compensation claims, have become increasingly important in forensic medicine. In view of this, a reliable diagnostic method of assessing cervical range of motion (ROM) is needed. The aim of the present study was to evaluate neck function with a 3D kinematic method compared with clinical evaluation in whiplash injury. Seventy consecutive patients (M/F = 18/52) with a history of whiplash injury (WH) and 46 healthy volunteers (M/F = 24/22), mean age, respectively 33 +/- 9 and 28 +/- 6 years (mean+/-SD) entered the study. Patients suffered from neck pain and/or unilateral headache. A computerized kinematic analysis of the ROM (Elite system) using passive markers and two infrared TV cameras was used. Clinical evaluation of active ROM was also performed both in patients and in 61 controls (M/F = 23/38; mean age 47 +/- 18 years). Thirty out of 70 patients were tested at the time of their first consultation (T0) and 6 months later (T6), and 12 were also followed up after a year (T12). All neck movements, except extension, were significantly reduced in WH subjects compared with controls, in particular lateral bending. Comparing ROM at T0, T6 and T12, no significant differences were found. A global index of motion (GIM), obtained by calculating the sum of ROM in absolute value for all the movements acquired, was significantly reduced in WH compared with control subjects. The interobserver reliability of the clinical evaluation was globally acceptable. On the basis of the clinical evaluation, a significantly reduced ROM was found in all movements in WH subjects compared with an age-matched population. Computing the number of impaired cervical movements (ICMs), a significantly higher number was observed in WH patients than in controls, showing a decreasing trend at T6 and T12, with a significant improvement at T6 vs. T0. The computerized study of neck ROM may constitute a useful tool in the evaluation of WH at baseline and follow-up.

Eye movement abnormalities in myotonic dystrophy.

We studied saccade and smooth pursuit eye movements in 31 patients suffering from myotonic dystrophy (MD). On the basis of mean value comparisons, saccades were slower and hypometric and smooth pursuit eye movements performed worse in MD patients than in controls. On an individual basis, saccade duration was prolonged in 67.7%, saccades were hypometric in 19.4%, saccade latency was delayed in 9.7%, and the smooth pursuit performance index was decreased in 9.7% of patients. Eye movement abnormalities did not correlate with those detectable by visual, brain-stem auditory and somatosensory evoked potentials. We attempted to classify eye movement abnormalities as myogenic or neurogenic on the basis of differences in combination of eye movement abnormalities and the occurrence of D5/D35 dissociation; the latter consists of a prolonged duration for large (35 degrees) but not for small (5 degrees) saccades. Since D5/D35 dissociation occurred in 26/33 multiple sclerosis patients with increased saccade duration, we considered it to be a neurogenic pattern attributable to a central nervous system (CNS) dysfunction. A prolonged duration without dissociation especially in combination with saccade hypometria, is interpreted as a myogenic pattern, although the lack of dissociation may also occur with CNS impairment in case of a marked increase in saccade duration. Accordingly we classified the oculomotor abnormalities detected as neurogenic in 11 MD patients and as myogenic in another 10, but in some subjects belonging to the second group concomitant CNS impairment is not to be excluded.

La función ejecutiva en los adolescentes con síndrome de Down / No disponible

La función ejecutiva en las personas con síndrome de Down se había evaluado hasta ahora sólo en los adultos, encontrándose deteriorada; pero no se había analizado en edades anteriores, por lo que el deterioro podría deberse al envejecimiento precoz propio de este síndrome. En el este estudio se analiza en 15 adolescentes la función ejecutiva mediante el pase de una batería de pruebas que evalúan el cambio de contexto, la capacidad de planificación y resolver problemas, la memoria operacional, la capacidad para inhibirse y para mantener la atención. Los resultados muestran un deterioro generalizado, según se desprende de las pruebas que analizan el cambio de contexto, la planificación y resolución de problemas, la memoria operacional y la constancia en la atención. Se trata, pues, de una alteración propia del síndrome en sí, no del envejecimiento (AU)

No disponible