Long-term forgetting is independent of age in healthy children and adolescents.

Introduction: In clinical neuropsychology, the phenomenon of accelerated long-term forgetting (ALF) has advanced to be a marker for subtle but clinically relevant memory problems associated with a range of neurological conditions. The normal developmental trajectory of long-term memory, in this case, memory recall after 1 week, and the influence of cognitive variables such as intelligence have not extensively been described, which is a drawback for the use of accelerated long-term forgetting measures in pediatric neuropsychology. Methods: In this clinical observation study, we analyzed the normal developmental trajectory of verbal memory recall after 1 week in healthy children and adolescents. We hypothesized that 1-week recall and 1-week forgetting would be age-dependent and correlate with other cognitive functions such as intelligence and working memory. Sixty-three healthy participants between the ages of 8 and 16 years completed a newly developed auditory verbal learning test (WoMBAT) and the WISC-V intelligence test (General Ability Index, GAI). Using these tests, 1 week recall and 1 week forgetting have been studied in relation to GAI, verbal learning performance, and verbal working memory. Results: Neither 1-week recall nor 1-week forgetting seems to be age-dependent. They are also not significantly predicted by other cognitive functions such as GAI or working memory. Instead, the ability to recall a previously memorized word list after 7 days seems to depend solely on the initial learning capacity. Conclusion: In the clinical setting, this finding can help interpret difficulties in free recall after 7 days or more since they can probably not be attributed to young age or low intelligence.

Impaired episodic verbal memory recall after 1 week and elevated forgetting in children after mild traumatic brain injury - results from a short-term longitudinal study.

Objective: There is preliminary evidence that children after traumatic brain injury (TBI) have accelerated long-term forgetting (ALF), i.e., an adequate learning and memory performance in standardized memory tests, but an excessive rate of forgetting over delays of days or weeks. The main aim of this study was to investigate episodic memory performance, including delayed retrieval 1 week after learning, in children after mild TBI (mTBI). Methods: This prospective study with two time-points (T1: 1 week after injury and T2: 3-6 months after injury), included data of 64 children after mTBI and 57 healthy control children aged between 8 and 16 years. We assessed episodic learning and memory using an auditory word learning test and compared executive functions (interference control, working memory, semantic fluency and flexibility) and divided attention between groups. We explored correlations between memory performance and executive functions. Furthermore, we examined predictive factors for delayed memory retrieval 1 week after learning as well as for forgetting over time. Results: Compared to healthy controls, patients showed an impaired delayed recall and recognition performance 3-6 months after injury. Executive functions, but not divided attention, were reduced in children after mTBI. Furthermore, parents rated episodic memory as impaired 3-6 months after injury. Additionally, verbal learning and group, but not executive functions, were predictive for delayed recall performance at both time-points, whereas forgetting was predicted by group. Discussion: Delayed recall and forgetting over time were significantly different between groups, both post-acutely and in the chronic phase after pediatric mTBI, even in a very mildly injured patient sample. Delayed memory performance should be included in clinical evaluations of episodic memory and further research is needed to understand the mechanisms of ALF.

Long-term intellectual and developmental outcomes after pediatric epilepsy surgery: A systematic review and meta-analysis.

In addition to the primary aim of seizure freedom, a key secondary aim of pediatric epilepsy surgery is to stabilize and, potentially, optimize cognitive development. Although the efficacy of surgical treatment for seizure control has been established, the long-term intellectual and developmental trajectories are yet to be delineated. We conducted a systematic review and meta-analysis of studies reporting pre- and postsurgical intelligence or developmental quotients (IQ/DQ) of children with focal lesional epilepsy aged ≤18 years at epilepsy surgery and assessed at >2 years after surgery. We determined the IQ/DQ change and conducted a random-effects meta-analysis and meta-regression to assess its determinants. We included 15 studies reporting on 341 patients. The weighted mean age at surgery was 7.1 years (range = .3-13.8). The weighted mean postsurgical follow-up duration was 5.6 years (range = 2.7-12.8). The overall estimate of the mean presurgical IQ/DQ was 60 (95% confidence interval [CI] = 47-73), the postsurgical IQ/DQ was 61 (95% CI = 48-73), and the change was +.94 IQ/DQ (95% CI = -1.70 to 3.58, p = .486). Children with presurgical IQ/DQ ≥ 70 showed a tendency for higher gains than those with presurgical IQ/DQ < 70 (p = .059). Higher gains were determined by cessation of antiseizure medication (ASM; p = .041), not just seizure freedom. Our findings indicate, on average, stabilization of intellectual and developmental functioning at long-term follow-up after epilepsy surgery. Once seizure freedom has been achieved, ASM cessation enables the optimization of intellectual and developmental trajectories in affected children.

Lesion Extent Negatively Impacts Intellectual Skills in Pediatric Focal Epilepsy.

BACKGROUND: Cognitive development in children and adolescents with focal lesional epilepsy is determined by the underlying epileptogenic lesion, in addition to epilepsy itself. However, the impact of lesion-related variables on intelligence quotient (IQ) and developmental quotient (DQ) remains largely unexplored. Here, we aimed to determine the effect of lesion-related predictors and their relation with epilepsy-related predictors of intellectual functioning. METHODS: We retrospectively analyzed data from children with focal lesional epilepsy who underwent standardized cognitive evaluation yielding IQ/DQ in our institution. RESULTS: We included 50 consecutive patients aged 0.5 to 17.5 years (mean, 9.3; S.D., 4.9) at cognitive assessment. Epilepsy duration was 0 to 15.5 years (mean, 3.8; S.D., 4.1). Of the total cohort, 30 (60%) patients had unilobar lesions, seven (14%) multilobar, 10 (20%) hemispheric, and three (6%) bilateral. Etiology was congenital in 32 (64%) cases, acquired in 14 (28%), and progressive in four (8%). For patients with unilobar lesions, the mean IQ/DQ was 97.1 ± 15.7, for multilobar 98.9 ± 20.2, for hemispheric 76.1 ± 20.5, and for bilateral 76.3 ± 4.5. Larger lesion extent, earlier epilepsy onset, and longer epilepsy duration correlated with lower IQ/DQ in the univariate analysis, whereas only lesion extent and epilepsy duration contributed significantly to the explanatory model in the multivariable analysis. CONCLUSIONS: The present study demonstrates that lesion extent and epilepsy duration are important risk factors for intellectual impairment in pediatric patients with focal lesional epilepsy. These findings are useful for family counseling and the early consideration of interventions that may limit the duration of epilepsy.

Delayed episodic memory recall after one week is associated with executive functions and divided attention in pediatric epilepsy patients.

AIM: Recent studies suggest that although children with epilepsy may show normal learning and memory performance, accelerated long-term forgetting (ALF) may become evident over time. Our study examined associations between delayed episodic memory performance (recall 1-week after learning) and executive functions. METHOD: A consecutive sample of children with a diagnosis of idiopathic epilepsy with focal or generalized seizures, without morphologic or metabolic abnormalities (n = 20, mean age: 11.70 years) was compared to an IQ-matched healthy control group (n = 20, mean age: 11.55 years). We also assessed parents' and children's rating of forgetting in everyday life and explored its association with delayed episodic memory recall. RESULTS: Similar to results from recent studies of pediatric patients with temporal lobe epilepsy or genetic generalized epilepsy, our pediatric epilepsy patients showed a significantly elevated recall loss over time, although verbal learning, immediate and 30-minute recall was comparable to the matched control group. Additionally, delayed memory recall in patients was moderately associated with their subjective rating of forgetting, as well as with executive functions (verbal fluency and switching) and divided attention. INTERPRETATION: We assume that executive functions play a crucial role in deep memory encoding, facilitating stronger and more enduring memory traces. Given that approximately 20% of epilepsy patients - compared to a healthy reference sample - had a significantly reduced delayed recall and due to the clinical relevance of long-term memory, age-appropriate standard norms for free memory recall after 1-week are desirable.

Optimized quantitative magnetic resonance spectroscopy for clinical routine.

Several practical obstacles in data handling and evaluation complicate the use of quantitative localized magnetic resonance spectroscopy (qMRS) in clinical routine MR examinations. To overcome these obstacles, a clinically feasible MR pulse sequence protocol based on standard available MR pulse sequences for qMRS has been implemented along with newly added functionalities to the free software package jMRUI-v5.0 to make qMRS attractive for clinical routine. This enables (a) easy and fast DICOM data transfer from the MR console and the qMRS-computer, (b) visualization of combined MR spectroscopy and imaging, (c) creation and network transfer of spectroscopy reports in DICOM format, (d) integration of advanced water reference models for absolute quantification, and (e) setup of databases containing normal metabolite concentrations of healthy subjects. To demonstrate the work-flow of qMRS using these implementations, databases for normal metabolite concentration in different regions of brain tissue were created using spectroscopic data acquired in 55 normal subjects (age range 6-61 years) using 1.5T and 3T MR systems, and illustrated in one clinical case of typical brain tumor (primitive neuroectodermal tumor). The MR pulse sequence protocol and newly implemented software functionalities facilitate the incorporation of qMRS and reference to normal value metabolite concentration data in daily clinical routine.

Macrocephaly in neurofibromatosis type 1: a sign post for optic pathway gliomas?

PURPOSE: Optic pathway gliomas, which occur in 15-20% of paediatric patients with neurofibromatosis type 1, are the most common central nervous system tumour associated with this neurocutaneous disorder. The detection of optic pathway gliomas is essential for further management but is often delayed in infancy due to oligosymptomatic progression and difficulties in clinical detection. Therefore, the aim of our study was to find a clinical indicator for the presence of optic pathway gliomas in children with neurofibromatosis type 1 in order to facilitate early diagnosis and initiate further ophthalmological and neuroimaging investigations. METHODS: We retrospectively evaluated 70 patients (mean age of 10.5 years; SD of 4.3 years; range of 0.5-19.6 years; 35 females) with neurofibromatosis type 1 seen at the University Children's Hospital of Bern, Switzerland, between January 1998 and December 2008 regarding clinical features of neurofibromatosis type 1 in relation to the presence of optic pathway gliomas. RESULTS: Fifty-seven of the 70 patients (81.4%) had no clinical or radiological signs of optic pathway gliomas [magnetic resonance imaging (MRI) of the brain in 26/57], whereas 13/70 patients (18.6%) were diagnosed with optic pathway gliomas by MRI. Patients with optic pathway gliomas showed macrocephaly significantly more often compared to patients without optic pathway gliomas (8/13 vs. 9/57, respectively; p = 0.004). CONCLUSION: Macrocephaly significantly correlates with the incidence of optic pathway gliomas in children with neurofibromatosis type 1. We therefore hypothesise that in otherwise asymptomatic patients, macrocephaly is an additional indicator for performing MRI to detect optic pathway gliomas.

Brain metabolite composition in relation to cognitive function and dystrophin mutations in boys with Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is a hereditary X-linked recessive disorder affecting the synthesis of dystrophin, a protein essential for structural stability in muscle. Dystrophin also occurs in the central nervous system, particularly in the neocortex, hippocampus and cerebellum. Quantitative metabolic analysis by localized (1) H MRS was performed in the cerebellum (12 patients and 15 controls) and a temporo-parietal location (eight patients and 15 controls) in patients with DMD and healthy controls to investigate possible metabolic differences. In addition, the site of individual mutations on the dystrophin gene was analyzed and neuropsychological cognitive functions were examined. Cognitive deficits in the patient group were found in line with earlier investigations, mainly concerning verbal short-term memory, visuo-spatial long-term memory and verbal fluency, but also the full-scale IQ. Causal mutations were identified in all patients with DMD. Quantitative MRS showed consistent choline deficits, in both cerebellar white matter and temporo-parietal cortex, as well as small, but significant, metabolic abnormalities for glutamate and total N-acetyl compounds in the temporo-parietal region. Compartment water analysis did not reveal any abnormalities. In healthy subjects, choline levels were age related in the cerebellum. The choline deficit contrasts with earlier findings in DMD, where a surplus of choline was postulated for the cerebellum. In patients, total N-acetyl compounds in the temporo-parietal region were related to verbal IQ and verbal short-term memory. However, choline, the putative main metabolic abnormality, was not found to be associated with cognitive deficits. Furthermore, in contrast with the cognitive performance, the metabolic brain composition did not depend significantly on whether or not gene mutations concerned the expression of the dystrophin isoform Dp140, leading to the conclusion that the effect of the missing Dp140 isoform on cognitive performance is not mediated through the observed metabolite composition, or is caused by local effects beyond the resolution accessible to MRS investigations.

Long-term sequelae after acquired pediatric hemorrhagic cerebellar lesions.

PURPOSE: The aim of the present study was to assess cognitive, affective, and motor long-term sequelae after acquired focal pediatric cerebellar lesions. METHODS: Eight patients with a history of isolated acquired hemorrhagic cerebellar lesions before the age of 13 participated in this study. All participants underwent a neurologic examination, including the Zurich Neuromotor Assessment (ZNA) and the International Cooperative Ataxia Rating Scale (ICARS). Cognitive functions have been evaluated with a general cognitive assessment and an extensive neuropsychological battery. Furthermore, patients and parents filled in questionnaires about quality of life and possible behavioral or emotional problems. RESULTS: The results revealed that all patients exhibited motor problems (ZNA). Most participants had further restricted oculomotor movements (ICARS). Age at injury and the full scale IQ were significantly positively correlated (Pearson correlation 0.779; p = 0.023). Conversely, no overall neuropsychological profile could be identified except for marginally reduced reaction times and susceptibility to interference. In addition, borderline results in semantic and phonemic word fluency tasks were apparent. A dysexecutive syndrome was diagnosed in one patient. However, verbal performance and reading abilities were non-pathologic in all participants. The patients reported having a good quality of life without major physical restrictions. CONCLUSIONS: Emotional disturbances and the presence of a mild cerebellar cognitive affective syndrome (as frequently described in adult patients) could only be confirmed in adolescents with vermis lesions. Nevertheless, in laboratory conditions, neuropsychological impairments were present in all patients. Heterogeneity of age at injury and exact lesion site may have led to interpersonal differences in neuropsychological outcome.

Neuropsychological impairments and the impact of dystrophin mutations on general cognitive functioning of patients with Duchenne muscular dystrophy.

Mutations in the dystrophin gene have long been recognised as a cause of mental retardation. However, for reasons that are unclear, some boys with dystrophin mutations do not show general cognitive deficits. To investigate the relationship between dystrophin mutations and cognition, the general intellectual abilities of a group of 25 boys with genetically confirmed Duchenne muscular dystrophy were evaluated. Furthermore, a subgroup underwent additional detailed neuropsychological assessment. The results showed a mean full scale intelligence quotient (IQ) of 88 (standard deviation 24). Patients performed very poorly on various neuropsychological tests, including arithmetics, digit span tests and verbal fluency. No simple relationship between dystrophin mutations and cognitive functioning could be detected. However, our analysis revealed that patients who lack the dystrophin isoform Dp140 have significantly greater cognitive problems.

Cerebral sinus venous thrombosis in Swiss children.

UNLABELLED: AIMo describe the characteristics of paediatric cerebral sinus venous thrombosis (CSVT) in Switzerland. METHOD: data on clinical features, neuroimaging, risk factors, and treatment were collected for all children in Switzerland younger than 16 years of age who had CSVT between January 2000 and December 2008. A follow-up examination and a cognitive assessment were performed (mean follow-up period 26mo). Differences between neonates and children (patients older than 28d) were assessed and predictors of outcome were determined. RESULTS: twenty-one neonates (14 males, seven females; mean age 9d, SD 8d) and 44 children (30 males, 14 females; mean age 8y 7mo, SD 4y 5mo) were reported. The incidence of paediatric CSVT in Switzerland was 0.558 per 100000 per year. In neonates, the deep venous system was more often involved and parenchymal injuries were more common. The strongest predictor of poor outcome was neonatal age (odds ratio 17.8, 95% confidence interval 0.847-372.353). Most children showed global cognitive abilities within the normal range, but impairments in single cognitive subdomains were frequent. INTERPRETATION: paediatric CSVT is rare. Its outcome is poor in neonates. Most children have good neurological outcomes, but some patients have individual neuropsychological impairments.

Lateralization of cognitive functions after stroke in childhood.

RATIONALE: A child's brain shows a remarkable ability to recover from adverse events such as stroke. Language functions recover particularly well, while visuo-spatial skills are more affected by brain damage, regardless of its localization. This study investigated the lateralization of language and visual search after childhood stroke. METHODS: Ten patients with unilateral stroke (aged 10-19 years, five left-, five right-sided lesion) and 20 healthy controls (aged 8-20 years) completed a neuropsychological test battery and functional magnetic resonance imaging (fMRI) intended to activate predominantly right (visual search) and left-sided functional networks (language). RESULTS: After stroke, patients demonstrated atypical lateralization of visual search functions (8/10 patients, left lateralization) more often than that of language (4/10 patients, right lateralization). There was a dissociation between the lateralization of productive and semantic language (4/10 patients, 1/20 controls) and between the lateralization of simple and complex visual search (3/10 patients, 3/20 controls). In patients, atypical contralateral activations occurred in the same areas that showed decreasing activation during development in healthy participants. CONCLUSION: The lateralization of functions depends upon the cognitive function measured. Dissociation between the lateralization of different language or visual search tasks can occur.