Approximately 2 of every 3 of all pediatric patients with brain tumors will be long-term survivors. However, there is a steep cost for pediatric brain tumor survivors, and the group as a whole faces significantly more late effects than many other survivors of pediatric cancers. Most of these effects can be attributed to direct neurologic damage to the developing brain caused by the tumor and its removal, the long-term toxicity of chemotherapy, or the effects of irradiation on the central nervous system. The late effects experienced by childhood brain tumor survivors involve multiple domains. This article will review the significant late effects that occur within the medical, neurocognitive, psychosocial, and economic domains of the survivorship experience. We conclude by discussing how the late effects in different domains often coexist and can create a complex set of obstacles that pose significant challenges for a survivor of a pediatric brain tumor on a daily basis.

Late effects of therapy for pediatric brain tumor survivors.

Subcortical structures and cognition : , Subcortical structures and cognition : , کتابخانه دیجیتال جندی شاپور اهواز

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Subcortical structures and cognition

Posterior fossa syndrome is characterized by cerebellar dysfunction, oromotor/oculomotor apraxia, emotional lability and mutism in patients after infratentorial injury. The underlying neuroanatomical substrates of posterior fossa syndrome are unknown, but dentatothalamocortical tracts have been implicated. We used pre- and postoperative neuroimaging to investigate proximal dentatothalamocortical tract involvement in childhood embryonal brain tumour patients who developed posterior fossa syndrome following tumour resection. Diagnostic imaging from a cohort of 26 paediatric patients previously operated on for an embryonal brain tumour (13 patients prospectively diagnosed with posterior fossa syndrome, and 13 non-affected patients) were evaluated. Preoperative magnetic resonance imaging was used to define relevant tumour features, including two potentially predictive measures. Postoperative magnetic resonance and diffusion tensor imaging were used to characterize operative injury and tract-based differences in anisotropy of water diffusion. In patients who developed posterior fossa syndrome, initial tumour resided higher in the 4th ventricle ( P = 0.035). Postoperative magnetic resonance signal abnormalities within the superior cerebellar peduncles and midbrain were observed more often in patients with posterior fossa syndrome ( P = 0.030 and 0.003, respectively). The fractional anisotropy of water was lower in the bilateral superior cerebellar peduncles, in the bilateral fornices, white matter region proximate to the right angular gyrus (Tailerach coordinates 35, –71, 19) and white matter region proximate to the left superior frontal gyrus (Tailerach coordinates –24, 57, 20). Our findings suggest that multiple bilateral injuries to the proximal dentatothalamocortical pathways may predispose the development of posterior fossa syndrome, that functional disruption of the white matter bundles containing efferent axons within the superior cerebellar peduncles is a critical underlying pathophysiological component of posterior fossa syndrome, and that decreased fractional anisotropy in the fornices and cerebral cortex may be related to the abnormal neurobehavioural symptoms of posterior fossa syndrome.

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Proximal dentatothalamocortical tract involvement in posterior fossa syndrome

The spectrum of neurobehavioural deficits in the Posterior Fossa Syndrome in children after cerebellar tumour surgery

Confusion has surrounded the description of post-operative mutism and associated morbidity in pediatric patients with cerebellar tumors for years. The heterogeneity of definitions and diagnostic features has hampered research progress within the field, and to date, no international guidelines exist on diagnosis, prevention, treatment, or follow-up of this debilitating condition. An international group of clinicians and researchers from multiple relevant disciplines recently formed a cohesive panel to formulate a new working definition and agree upon standardized methods for diagnosis and follow-up. Consensus was obtained using the modified nominal group technique, involving four rounds of online Delphi questionnaires interspersed with a structured consensus conference with lectures, group work, and open discussion sessions. A new, proposed definition of “post-operative pediatric CMS” was formed, preliminary recommendations for diagnostic and follow-up procedures were created, two working groups on a new scoring scale and risk prediction and prevention were established, and areas were identified where further information is needed. The consensus process was motivated by desire to further research and improve quality of life for pediatric brain tumor patients. The Delphi rounds identified relevant topics and established basic agreement, while face-to-face engagement helped resolve matters of conflict and refine terminology. The new definition is intended to provide a more solid foundation for future clinical and research work. It is thought as a consensus for moving forward and hopefully paves the way to developing a standard approach to this challenging problem with the advent of better scoring methods and ultimate goal of reducing the risk of CMS.

Consensus paper on post-operative pediatric cerebellar mutism syndrome: the Iceland Delphi results.

Following cerebellar tumor resection, some patients develop transient cerebellar mutism (TCM). Although the mutism resolves, it is not known whether there are long-term motor speech deficits in patients with TCM that are in excess of those in individuals with cerebellar tumors who had not developed postoperative TCM. Long-term survivors of cerebellar tumors resected in childhood who developed TCM were matched to survivors without TCM and to controls. Speech samples were formally analyzed by two speech pathologists. Tumor survivors who had TCM had significantly more ataxic dysarthric speech and slower speech than either those without TCM or controls and were more dysfluent than controls. Tumor survivors without TCM did not differ from controls on ataxic dysarthria or speech rate. Survivors who had TCM showed more speech deficits than controls or survivors without TCM. The data suggest that speech deficits are chronic if not permanent sequelae of TCM.

Long-term effects of transient cerebellar mutism after cerebellar astrocytoma or medulloblastoma tumor resection in childhood.

The cerebellum is important for the coordination of fluent speech. The authors studied how childhood cerebellar tumors affect long-term neuromotor speech outcomes, including the relation between outcome and tumor type, radiation, age at diagnosis, and survival years. Videotaped speech samples of child and adult long-term survivors of childhood cerebellar astrocytoma (nonradiated) and medulloblastoma (radiated) tumors and healthy controls were analyzed by 2 speech pathologists for ataxic dysarthria, dysfluency, and speech rate. Ataxia varied with tumor type/radiation. Medulloblastoma survivors had significantly more ataxic dysarthric features than either survivors of astrocytomas or controls, who did not differ from each other. Dysfluency varied with a history of a posterior fossa tumor. Medulloblastoma and astrocytoma survivors were each significantly more dysfluent than controls but did not differ from each other. Speech rate varied with age and tumor type. Adult controls were significantly faster than child controls, although adult tumor survivors were comparable to their child counterparts. Adult controls had significantly faster speech rates than adult survivors of medulloblastoma tumors. Ataxic dysarthric speech characteristics are more frequent in radiated survivors of medulloblastoma tumors than nonradiated survivors of astrocytoma tumors. Dysfluent and slow speech occur in cerebellar tumor survivors, regardless of tumor type and radiation history. Cerebellar tumors in childhood limit speech rate in adulthood.

Long-Term Neuromotor Speech Deficits in Survivors of Childhood Posterior Fossa Tumors: Effects of Tumor Type, Radiation, Age at Diagnosis, and Survival Years:

Kim Bradley

Papers

Long-term effects of transient cerebellar mutism after cerebellar astrocytoma or medulloblastoma tumor resection in childhood.

Long-Term Neuromotor Speech Deficits in Survivors of Childhood Posterior Fossa Tumors: Effects of Tumor Type, Radiation, Age at Diagnosis, and Survival Years: