The role of cerebellum in the child neuropsychological functioning

Cerebellar cognitive affective syndrome with long-term features of autism spectrum disorder: evidence in a 9-year-old girl after vermian medulloblastoma surgery

The time course of socio-communicative disturbances in children after posterior fossa tumor resection is variable in clinical reports, and its assessment may help to understand the role of the cerebellum in the pathogenesis of socio-communicative disorders and improve rehabilitation plans. We report the 3-year cognitive-behavioral follow-up of a female patient (LZ) who underwent surgical ablation of the vermis due to medulloblastoma at age 9. LZ developed a severe post-operative Cerebellar Cognitive Affective Syndrome (CCAS) with cognitive-executive dysfunctions and behavioral alterations resembling an Autism Spectrum Disorder (ASD)-like syndrome. The lack of empathy and reduced ability to recognize others' intentions and mental states persisted at follow-up evaluations, as did language alterations. The present case report evidenced that lesions affecting cerebellar and vermal lobules may cause severe CCAS and impairment of social skills overlapping with that observed in ASD. This case is significant in its clinical features, revealing long-term social impairment, while the cognitive, linguistic, and executive functioning improved over time. Prospective case studies should plan the evaluation of symptoms of ASD within the clinical longitudinal assessment.

Sociocultural variables have a major impact on participation in patients treated for paediatric posterior fossa tumours

BACKGROUND

This study investigates the severeness of participation barriers in patients surviving paediatric posterior fossa tumours (PFT) many years after treatment. In the past, aetiological studies on adverse outcome have primarily focused on pathobiological risk factors. The current analysis aims to investigate the importance of environmental variables.

METHODS

On average, 10 years after diagnosis, educational and social difficulties of 42 patients surviving paediatric PFT (mean age 17 years) were inquired using a self-constructed questionnaire following the Psychosocial Resource-Orientated Assessment (PREDI). Educational or social participation barriers were defined by self- and/or proxy-reported difficulties in school or in peer relationships. Accordingly, the children and adolescents were categorized into groups of adequate and limited participation. Subsequently, the study identified potential pathobiological (treatment type, hydrocephalus, tumour relapse, gender, age at diagnosis, seizures and cerebellar mutism) and environmental (parental and maternal education, siblings, main language, discrepancies between personal and environmental values, regular physical activity and private living space) risk factors and investigated whether patients with adequate and limited participation differed in the number of risk factors.

RESULTS

Almost one decade after treatment, two thirds of patients experienced educational and/or social difficulties. Patients with limited participation were more frequently associated with environmental factors such as low maternal education degree, siblings, main language other than German, discrepancies between societal and personal values and irregular physical activity, as well as the pathobiological risk factors treatment type, hydrocephalus, tumour relapse, cerebellar mutism and seizures. These variables significantly discriminated between patients with and without limited participation.

CONCLUSIONS

Limited participation in patients treated for paediatric PFT is common. Next to pathobiological, also environmental risk factors play a major role in educational and social participation barriers. This highlights the fact that solely considering pathobiology is not sufficient when investigating risk factors for the emergence of late sequelae. Future aetiological studies must adopt a biopsychosocial perspective.

The Cerebellar Mutism Syndrome: Risk Assessment, Prevention and Treatment

Cerebellar mutism syndrome (CMS) has received increasing attention over the last decades as a complication of posterior fossa tumour surgery in children. Risk factors, aetiological aspects, and treatment measures of the syndrome have been investigated, yet the incidence of CMS remains unchanged. Overall, we are currently able to identify patients at risk, but we are unable to prevent it from occurring.Once CMS sets in, several symptomatic pharmacological treatments have been suggested, but only in smaller case series and not in randomized controlled trials, and it is not clear whether the treatment or time itself had a helpful effect.Within weeks to months, most patients regain their ability to speak after a phase with mutism or severely reduced speech; however, many patients continue to have speech and language deficits. At this point, anti-cancer treatment with chemotherapy and radiotherapy may be of focus more than the prognosis of CMS; however, many patients continue to have speech and language problems for months and years to come, and they are at high risk of other neurocognitive sequelae as well.Without reliable measures to prevent or treat the syndrome, we may look towards improving the prognosis of speech and neurocognitive functioning in these patients. As speech and language impairment is the cardinal symptom and late effect of CMS, the effect of intense and early-onset speech and language therapy as a standard of care in these patients should be investigated in relation to its effect on regaining speech capacity.

Evaluating the diagnostic validity of the Cerebellar Cognitive Affective Syndrome (CCAS) in pediatric posterior fossa tumour patients

Background

The aim of this case-control study was to investigate the severity of the cerebellar cognitive affective syndrome (CCAS) in patients treated for pediatric posterior fossa tumors (PFT) and evaluate its diagnostic validity and predictive value for long-term effects.

Methods

Using neuropsychological test data from 56 patients with PFT (average age: 14 years), the severity of deficits in the CCAS core areas (executive functions, verbal functions, visuospatial abilities and emotions/behaviour) was examined. Neuropsychological and academic long-term outcomes of patients with CCAS were compared to two control groups of PFT patients (treated with either surgery or surgery followed by radio-/chemotherapy) without the syndrome. Risk factors associated with various deficits were considered.

Results

All but one PFT patient suffered from slight to severe impairments in at least one CCAS domain, while complete CCAS occurred in 35.7%. Seven years after tumor diagnosis CCAS patients performed worse in information processing, logical reasoning, verbal functions, visuospatial skills, and executive functioning and required more special educational support compared to the control groups. CCAS patients performed equally poor as patients treated with chemo-/radiotherapy in tasks measuring information processing speed. Risk factors were significantly associated with deficits in information processing speed but not CCAS emergence.

Conclusions

Deficits in the core CCAS domains are commonly found in PFT patients, but varying in severity, which suggests the syndrome to be continuous rather than dichotomous. However, the validity of CCAS diagnosis was low and unspecific. The exclusion of relevant functions typically impaired in PFT patients (eg, information processing) resulted in difficulties being overlooked.

Networking of the Human Cerebellum: From Anatomo-Functional Development to Neurosurgical Implications

In the past, the cerebellum was considered to be substantially involved in sensory-motor coordination. However, a growing number of neuroanatomical, neuroimaging, clinical and lesion studies have now provided converging evidence on the implication of the cerebellum in a variety of cognitive, affective, social, and behavioral processes as well. These findings suggest a complex anatomo-functional organization of the cerebellum, involving a dense network of cortical territories and reciprocal connections with many supra-tentorial association areas. The final architecture of cerebellar networks results from a complex, highly protracted, and continuous development from childhood to adulthood, leading to integration between short-distance connections and long-range extra-cerebellar circuits. In this review, we summarize the current evidence on the anatomo-functional organization of the cerebellar connectome. We will focus on the maturation process of afferent and efferent neuronal circuitry, and the involvement of these networks in different aspects of neurocognitive processing. The final section will be devoted to identifying possible implications of this knowledge in neurosurgical practice, especially in the case of posterior fossa tumor resection, and to discuss reliable strategies to improve the quality of approaches while reducing postsurgical morbidity.