Differences in Supratentorial Damage of White Matter in Pediatric Survivors of Posterior Fossa Tumors With and Without Adjuvant Treatment as Detected by Magnetic Resonance Diffusion Tensor Imaging

Long-term supratentorial brain structure and cognitive function following cerebellar tumour resections in childhood

“…While we are not aware of any studies investigating supratentorial grey matter volumes in this patient group, a few recent studies using DTI to investigate white-matter microstructural properties have reported reduced fractional anisotropy (FA) in patients treated for cerebellar medulloblastomas (Leung et al, 2004;Rueckriegel et al, 2010;Soelva et al, 2013). Further, degree of whitematter abnormalities (both volume, FA and radial diffusivity [RD]) has been shown to correlate with the severity of cognitive deficits (Brinkman et al, 2012;Khong et al, 2003;Mabbott, et al, 2006;Mulhern et al, 2001;Reddick et al, 2003).…”

“…Further, degree of whitematter abnormalities (both volume, FA and radial diffusivity [RD]) has been shown to correlate with the severity of cognitive deficits (Brinkman et al, 2012;Khong et al, 2003;Mabbott, et al, 2006;Mulhern et al, 2001;Reddick et al, 2003). Although the craniospinal radiation therapy and chemotherapy used in the treatment of medulloblastomas may be partly responsible for these effects, reduced FA has also been found in patients with cerebellar astrocytomas, where treatment is limited to surgery (Rueckriegel et al, 2010;Soelva et al, 2013). The first aim of the present study was to compare supratentorial brain structure and cognitive function between patients with surgical resections of cerebellar tumours and matched controls, utilising advanced multimodal MRI -including voxel-based morphometry (VBM) and DTI -in combination with neuropsychological testing.…”

“…Importantly, however, any observed group differences might not be directly related to the cerebellar lesion, but rather to concomitant complications such as hydrocephalus, typically occurring in about 80-90% of cerebellar astrocytoma patients (Due-Tønnessen et al, 2013;Kameda-Smith et al, 2013) due to blocking of the aqueduct by the tumour mass. This latter possibility is especially relevant with respect to white matter, as hydrocephalus may have direct neurotoxic effects on periventricular white matter (Hattori et al, 2012;Scheel et al, 2012;Yuan et al, 2013), possibly due to decreased perfusion and oedema caused by the elevated pressure (Rueckriegel et al, 2010). Studies aimed at investigating the cognitive role of the cerebellum critically rely on the assumption that resection of cerebellar tissue is the main causal factor explaining structural and cognitive outcomes.…”

White and Gray Matter Abnormalities After Cranial Radiation in Children and Mice

“…Increased radiation dose is a significant risk factor for decreased intelligence quotient (IQ), reduced academic performance, and impairments in measurements of processing speed, memory, and executive function (6)(7)(8)(9). Magnetic resonance imaging (MRI) measurements have identified reduced white matter (WM) volume, altered WM structure, and possible changes in hippocampal volume due to CRT (10)(11)(12). These measurements correlate with behavioral outcomes (12)(13)(14)(15), suggesting an intuitive link between normal brain development and proper brain function.…”

Reduced-Distortion Diffusion MRI of the Craniovertebral Junction

“…17,18 Furthermore, fractional anisotropy has been shown to be a good clinical biomarker in detecting the lesions in the brain stem or the posterior fossa, as well as effects of radiation therapy. [19][20][21] Acute stroke lesions in the brain stem are also often missed by DWI because of susceptibility artifacts. 22,23 Here we show that RS-EPI results-qualitatively and quantitatively-in significantly less distortion than SS-EPI in the diffusion trace images, especially at the base of the temporal lobe and the cerebellum.…”