No abstract

Conventional, anatomical MRI is an essential tool for diagnosis and evaluation of location, quality, and extent of posterior fossa tumors, but offers limited information regarding tumor grade and type. Advanced MRI techniques such as diffusion weighted imaging (DWI) and diffusion tensor imaging (DTI) may improve the specific diagnosis of brain tumors in the posterior fossa in children. In this review the conventional neuroimaging findings, as well as the DWI, and DTI characteristics of common pediatric posterior fossa tumors are discussed and summarized.

Childhood craniopharyngiomas are histologically benign tumours arising from remnants of Rathke's pouch in the hypothalamic-pituitary region. The two common treatment approaches are primary total resection or limited resection followed by radiotherapy. To study the outcome after a primary surgical approach, we followed 25 consecutive patients (10 females, 15 males) under 16 years of age who were treated in a single institution with a management policy of radical tumour excision (mean age at diagnosis 9 years 2 months, SD 4 years 3 months; range 2 years 9 months to 15 years 11 months). Mean follow-up after primary surgery was 11 years 3 months (SD 7 years 7 months). Tumour control, and neurological, endocrine, and hypothalamic complications and their impact on health-related quality of life were assessed (medical follow-up, semi-structured interview, and questionnaires). Results of tumour control were generally good, however, local failure was observed in 6 of 25 patients, and severe late-treatment complications decreased quality of life for many long-time survivors. Endocrine deficiency occurred in 24/25, visual complications in 16/24, neurological complications in 8/24, obesity in 14/23, increased daytime sleepiness in 6/21, and significant school problems in 10/20. Patients with craniopharyngioma rated their health-related quality of life as considerably lower than healthy controls; the domains of social and emotional functioning were particularly affected. Parents' ratings were considerably lower than those of the patients. Poor functional outcome was associated with large tumours infiltrating or displacing the hypothalamus, the occurrence of hydrocephalus, and young age at diagnosis, but also with multiple operations due to tumour recurrence. Alternative treatment strategies should be considered, especially in very young patients with large tumours.

No abstract

No abstract

Cerebellar hypoplasia (CH) refers to a cerebellum with a reduced volume, and is a common, but non-specific neuroimaging finding. The etiological spectrum of CH is wide and includes both primary (malformative) and secondary (disruptive) conditions. Primary conditions include chromosomal aberrations (e.g., trisomy 13 and 18), metabolic disorders (e.g., molybdenum cofactor deficiency, Smith-Lemli-Opitz syndrome, and adenylosuccinase deficiency), genetic syndromes (e.g., Ritscher-Schinzel, Joubert, and CHARGE syndromes), and brain malformations (primary posterior fossa malformations e.g., Dandy-Walker malformation, pontine tegmental cap dysplasia and rhombencephalosynapsis, or global brain malformations such as tubulinopathies and α-dystroglycanopathies). Secondary (disruptive) conditions include prenatal infections (e.g., cytomegalovirus), exposure to teratogens, and extreme prematurity. The distinction between malformations and disruptions is important for pathogenesis and genetic counseling. Neuroimaging provides key information to categorize CH based on the pattern of involvement: unilateral CH, CH with mainly vermis involvement, global CH with involvement of both vermis and hemispheres, and pontocerebellar hypoplasia. The category of CH, associated neuroimaging findings and clinical features may suggest a specific disorder or help plan further investigations and interpret their results. Over the past decade, advances in neuroimaging and genetic testing have greatly improved clinical diagnosis, diagnostic testing, recurrence risk counseling, and information about prognosis for patients and their families. In the next decade, these advances will be translated into deeper understanding of these disorders and more specific treatments.

No abstract

Childhood craniopharyngiomas are histologically benign tumours arising from remnants of Rathke's pouch in the hypothalamic—pituitary region. The two common treatment approaches are primary total resection or limited resection followed by radiotherapy. To study the outcome after a primary surgical approach, we followed 25 consecutive patients (10 females, 15 males) under 16 years of age who were treated in a single institution with a management policy of radical tumour excision (mean age at diagnosis 9 years 2 months, SD 4 years 3 months; range 2 years 9 months to 15 years 11 months). Mean follow‐up after primary surgery was 11 years 3 months (SD 7 years 7 months). Tumour control, and neurological, endocrine, and hypothalamic complications and their impact on health‐related quality of life were assessed (medical follow‐up, semi‐structured interview, and questionnaires). Results of tumour control were generally good, however, local failure was observed in 6 of 25 patients, and severe late‐treatment complications decreased quality of life for many long‐time survivors. Endocrine deficiency occurred in 24/25, visual complications in 16/24, neurological complications in 8/24, obesity in 14/23, increased daytime sleepiness in 6/21, and significant school problems in 10/20. Patients with craniopharyngioma rated their health‐related quality of life as considerably lower than healthy controls; the domains of social and emotional functioning were particularly affected. Parents’ratings were considerably lower than those of the patients. Poor functional outcome was associated with large tumours infiltrating or displacing the hypothalamus, the occurrence of hydrocephalus, and young age at diagnosis, but also with multiple operations due to tumour recurrence. Alternative treatment strategies should be considered, especially in very young patients with large tumours.