“Cerebellar lesions after low-grade tumor resection can induce memory impairment in children, similar to that observed in patients with frontal lesions”

Correlates of performance on the Child and Adolescent Memory Profile (ChAMP) in a mixed pediatric sample

This study aimed to determine some of the factors that influence performance on a comprehensive test of verbal and visual memory in children, the Child and Adolescent Memory Profile (ChAMP) in a mixed clinical sample (n = 178; 56% male, 67% White, median age 12 years). We used hierarchical linear regression analyses with ChAMP standard scores as the dependent variable, and parental education as well as Wechsler Intelligence Scale for Children-Fifth Edition (WISC-V) factor index scores as the independent variables. WISC-V Processing Speed and (to a lesser extent) Working Memory were statistically significant predictors of most ChAMP Index scores. In addition, WISC-V Verbal Comprehension contributed to the model for ChAMP Verbal Memory, and WISC-V Visual Spatial to the model for ChAMP Visual Memory. In each case better performance on the WISC-V was predictive of higher scores on the ChAMP, with large effect sizes. WISC-V variables also mediated the positive effect of parental education on ChAMP scores. We conclude that clinicians should consider performance on measures of speed of processing, working memory, language and visual-spatial skills as potential influences on ChAMP results that may suggest a specific memory deficit.

The long-term impact of cerebellar tumor resection on executive functioning, anxiety, and fear of pain: A mixed methodology pilot study

This pilot study investigated the long-term impact of a surgery-only treatment (no exposure to other treatments, such as chemotherapy and radiation) for pediatric cerebellar low-grade gliomas on executive function, anxiety, and fear of pain (FOP) beliefs. Twelve patients who underwent surgical glioma resection during childhood (surgery age was 4-16 years, study visit age was 10-28 years), and 12 pain-free controls matched for age, sex, race, and handedness were tested. The spatial extent of resection was precisely mapped using magnetic resonance imaging (MRI). Executive function, anxiety, and FOP were assessed using validated self-report age-appropriate questionnaires for children and adults. Structured clinical interviews at a post-surgery follow-up visit were completed (average: 89 months, range: 20-99). No significant differences in FOP (FOPQ-C t[14 = 1.81, p = 0.09; FOPQ-III t[4] = 0.29, p = 0.79), executive function scores (BRIEF t[20] = 0.30, p = 0.28), or anxiety scores (MASC t[16] = 0.19, p = 0.85; MAQ t[4] = 1.80, p = 0.15) were found in pediatric or adult patients compared to pain-free controls. Clinical interviews mainly categorized pediatric patients as not anxious. One participant reported mild/subclinical anxiety, and one had moderate clinical anxiety. Neither psychologists nor patients endorsed impairments to executive functioning, anxiety, or FOP. Our pilot results suggest that pediatric cerebellar tumor survivors treated with surgery-only have favorable long-term functioning related to these themes. While these results are promising, they will need to be replicated in a larger patient sample.

New Light on Prions: Putative Role of PrPc in Pathophysiology of Mood Disorders

Mood disorders are highly prevalent and heterogenous mental illnesses with devastating rates of mortality and treatment resistance. The molecular basis of those conditions involves complex interplay between genetic and environmental factors. Currently, there are no objective procedures for diagnosis, prognosis and personalization of patients' treatment. There is an urgent need to search for novel molecular targets for biomarkers in mood disorders. Cellular prion protein (PrPc) is infamous for its potential to convert its insoluble form, leading to neurodegeneration in Creutzfeldt-Jacob disease. Meanwhile, in its physiological state, PrPc presents neuroprotective features and regulates neurotransmission and synaptic plasticity. The aim of this study is to integrate the available knowledge about molecular mechanisms underlying the impact of PrPc on the pathophysiology of mood disorders. Our review indicates an important role of this protein in regulation of cognitive functions, emotions, sleep and biological rhythms, and its deficiency results in depressive-like behavior and cognitive impairment. PrPc plays a neuroprotective role against excitotoxicity, oxidative stress and inflammation, the main pathophysiological events in the course of mood disorders. Research indicates that PrPc may be a promising biomarker of cognitive decline. There is an urgent need of human studies to elucidate its potential utility in clinical practice.

Language outcomes in children who underwent surgery for the removal of a posterior fossa tumor: A systematic review

BACKGROUND

Children who underwent posterior fossa tumor removal may have spoken or written language impairments. The present systematic review synthesized the literature regarding the language outcomes in this population. Benefits of this work were the identification of shortcomings in the literature and a starting point toward formulating guidelines for postoperative language assessment.

METHODS

A systematic literature search was conducted, identifying studies with patients who had posterior fossa surgery before 18 years of age. Included studies were narratively synthesized to understand language outcomes by language function (e.g., phonology, morphosyntax) at a group and individual level. Furthermore, the influence of several mediators (e.g., postoperative cerebellar mutism syndrome (pCMS), tumor type) was investigated. A critical evaluation of the language assessment tools was conducted.

RESULTS

The narrative synthesis of 66 studies showed that a broad spectrum of language impairments has been described, characterized by a large interindividual heterogeneity. Patients younger at diagnosis, receiving treatment for a high-grade tumor and/or radiotherapy and diagnosed with pCMS seemed more prone to impairment. Several gaps in language assessment remain, such as a baseline preoperative assessment and the assessment of pragmatics and morphosyntax. Further, there were important methodological differences in existing studies which complicated our ability to accurately guide clinical practice.

CONCLUSION

Children who had posterior fossa surgery seem to be at risk for postoperative language impairment. These results stress the need for language follow-up in posterior fossa tumor survivors.

Involvement of the cerebellum in the regulation of executive functions in children—Preliminary analysis based on a neuropsychological study of children after cerebellar tumour surgery

Aim

Preliminary assessment of executive functions in children with cerebellar lesions, description of their emotional-social functioning and selection of sensitive neuropsychological tools to detect the cerebellar cognitive affective syndrome (CCAS).

Materials and methods

The study group consisted of 10 children after cerebellar tumour surgery. The control group consisted of 10 healthy children, matched for age and sex: The IDS-2 executive functions battery, the Conners 3 ADHD questionnaire, the Autism Spectrum Rating Scales (ASRS) and the International Cooperative Ataxia Rating Scale (ICARS) were used.

Results

Statistical analysis showed statistically significant differences between the experimental and control groups in terms of two dimensions of executive functioning. Children from experimental group was characterised by worse planning and divided attention than healthy controls. Moreover children with cerebellar lesions were characterised by significantly higher levels of some behaviours similar to that observed in autism spectrum disorders, namely difficulties in social relationships, self-regulation of emotions, attention, and greater behavioural rigidity. Test power analysis and estimation of the effect size by the Cohen’s d coefficient indicated that with a slight increase in the size of the experimental group, the probability of detecting statistically significant difference in the executive functions total measure score as well as in several ASRS subscales increased, but not in Conners 3 subscales.

Conclusions

Cerebellar damage may pose a risk for dysexecutive syndrome and social-emotional problems in children. The IDS-2 executive functions battery and the ASRS test are sufficiently sensitive tools to assess elements of the CCAS in children.

Cerebellar Functional Lateralization From the Perspective of Clinical Neuropsychology

Objective: The cerebellar functional laterality, with its right hemisphere predominantly involved in verbal performance and the left one engaged in visuospatial processes, has strong empirical support. However, the clinical observation and single research results show that the damage to the right cerebellar hemisphere may cause extralinguistic and more global cognitive decline. The aim of our research was to assess the pattern of cognitive functioning, depending on the cerebellar lesion side, with particular emphasis on the damage to the right cerebellar hemisphere.

Method: The study sample consisted of 31 patients with focal cerebellar lesions and 31 controls, free of organic brain damage. The Addenbrooke’s Cognitive Examination ACE III and the Trail Making Test TMT were used to assess patients’ cognitive functioning.

Results: Left-sided cerebellar lesion patients scored lower than controls in attention and visuospatial domain, but not in language, fluency, and memory functions. Participants with right-sided cerebellar lesion demonstrated a general deficit of cognitive functioning, with impairments not only in language and verbal fluency subscales but also in all ACE III domains, including memory, attention, and visuospatial functions. The TMT results proved that cerebellar damage is associated with executive function impairment, regardless of the lesion side.

Conclusion: The cognitive profiles of patients with cerebellum lesions differ with regard to the lesion side. Left-sided cerebellar lesions are associated with selective visuospatial and attention impairments, whereas the right-sided ones may result in a more global cognitive decline, which is likely secondary to language deficiencies, associated with this lateral cerebellar injury.

Is Addenbrooke's Cognitive Examination III Sensitive Enough to Detect Cognitive Dysfunctions in Patients with Focal Cerebellar Lesions?

OBJECTIVE

The main aim of the study was to evaluate whether the available brief test of mental functions Addenbrooke's cognitive examination III (ACE III) detects cognitive impairment in patients with cerebellar damage. The second goal was to show the ACE III cognitive impairment profile of patients with focal cerebellar lesions.

METHOD

The study sample consisted of 31 patients with focal cerebellar lesions, 78 patients with supratentorial brain damage, and 31 subjects after spine surgery or with spine degeneration considered as control group, free of organic brain damage. The ACE III was used.

RESULTS

Patients with cerebellar damage obtained significantly lower results in the ACE III total score and in several subscales: attention, fluency, language, and visuospatial domains than healthy controls without brain damage. With the cut-off level of 89 points, the ACE III was characterized by the sensitivity of 71%, specificity of 72%, and accuracy of 72%. The cerebellar cognitive impairment profile was found to be "frontal-like" and similar to that observed in patients with anterior supratentorial brain damage, with decreased ability to retrieve previously learned material and its preserved recognition, impaired word fluency, and executive dysfunction. The results are consistent with cerebellar cognitive affective syndrome.

CONCLUSIONS

The ACE III can be used as a sensitive screening tool to detect cognitive impairments in patients with cerebellar damage.

Possible association between the integrity of cerebellar pathways and neurocognitive performance in children with posterior fossa tumors

BACKGROUND

Cerebellar tumor survivors often exhibit neuropsychological deficits that could be related to alterations in cerebro-cerebellar networks. This is a pilot study designed to understand if diffusion tensor imaging (DTI)-based tractography is able to identify possible correlations between cerebellar white matter structure and cognitive outcome in children on long-term follow-up for posterior fossa (PF) tumors who were thoroughly assessed for neuropsychological functioning.

METHODS

DTI-based tractography was performed in pediatric patients with PF tumors. Fractional anisotropy (FA) and volumetric measurements of spinocerebellar, dentorubrothalamocortical and corticopontocerebellar tracts were analyzed. Cognitive and neuropsychological functioning was assessed by the Wechsler Intelligence Scale for Children-IV Edition (WISC-IV) and the Developmental Neuropsychological Assessment (NEPSY II). The associations between Full-Scale Intelligence Quotient (FSIQ), NEPSY-II scores, and fiber tracts were tested by the Spearman rank correlation coefficient.

RESULTS

Seven patients (median age at diagnosis five years, range, 3-13) treated for medulloblastoma (2/7; 29%) and pilocytic astrocytoma (5/7; 71%) were retrospectively evaluated. All children had complete surgery. The median FSIQ was 84 (range, 67-93). Patients presented with several deficits on many NEPSY-II tasks; in particular, memory was impaired in nearly half of them. FSIQ and neurocognitive tasks significantly correlated with specific corticopontocerebellar tracts.

CONCLUSION

Children on follow-up for PF tumor showed scattered cognitive impairments, including deficits in long-term and immediate memory. Tractography allowed us to describe a possible association between the integrity of cerebellar pathways and neurocognitive performance, suggesting that the myelinization of these fibers may represent an indicator for the development of long-term cognitive sequelae.