Changes to memory structures in children treated for posterior fossa tumors.
Children treated for medulloblastoma (MB) exhibit long-term impairments in declarative memory, but the pathophysiology underlying this is unclear. Previous studies report declines in global white matter volume, but have failed to link this to declines in memory performance. We examined the effects of treatment on measures of global brain structure (i.e., total white and gray matter volume) and specific memory structures (i.e., hippocampus and uncinate fasciculus). We used volumetric MRI and diffusion tensor imaging in pediatric survivors of MB and one survivor of astrocytoma treated with cranial-spinal radiation (n = 20), and healthy controls (n = 13). Compared to controls, the survivor group exhibited reduced white matter volume, damage to the uncinate fasciculus, and a smaller right hippocampus. Critically, reduced hippocampal volume was not related to differences in brain volume, suggesting that the hippocampus may be especially vulnerable to treatment effects. A subset of the survivors (n = 10) also underwent memory testing using the Children's Memory Scale (CMS). Performance on the general index of the CMS was significantly correlated with measures of hippocampal volume and uncinate fasciculus. The examination of treatment effects on specific brain regions provides a better understanding of long-term cognitive outcome in children with brain tumors, particularly medulloblastoma.
1 Neurosciences and Mental Health, Hospital for Sick Children, Toronto, Ontario.
Lily
L
Riggs
3 Department of Haematology/Oncology, Hospital for Sick Children, Toronto, Ontario.
Eric
E
Bouffet
5 Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario.
Suzanne
S
Laughlin
6 Radiation Oncology, Princess Margaret Hospital, Toronto, Ontario.
Normand
N
Laperriere
1 Neurosciences and Mental Health, Hospital for Sick Children, Toronto, Ontario.
Fang
F
Liu
1 Neurosciences and Mental Health, Hospital for Sick Children, Toronto, Ontario.
Jovanka
J
Skocic
1 Neurosciences and Mental Health, Hospital for Sick Children, Toronto, Ontario.
Nadia
N
Scantlebury
5 Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario.
Frank
F
Wang
1 Neurosciences and Mental Health, Hospital for Sick Children, Toronto, Ontario.
Nicholas J
NJ
Schoenhoff
7 Departments of Oncology and Pediatrics, University of Calgary, Calgary, Alberta.
Douglas
D
Strother
8 Department of Oncology, British Columbia Children's Hospital, Vancouver, British Columbia.
Juliette
J
Hukin
8 Department of Oncology, British Columbia Children's Hospital, Vancouver, British Columbia.
Christopher
C
Fryer
9 Department of Psychology, British Columbia Children's Hospital, Vancouver, British Columbia.
Dina
D
McConnell
1 Neurosciences and Mental Health, Hospital for Sick Children, Toronto, Ontario.
Donald J
DJ
Mabbott
D000293:Adolescent; D000704:Analysis of Variance; D001921:Brain / Q000473:pathology* / Q000528:radiation effects; D016022:Case-Control Studies; D002648:Child; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D015192:Infratentorial Neoplasms / Q000150:complications* / Q000473:pathology* / Q000532:radiotherapy; D008279:Magnetic Resonance Imaging; D008297:Male; D008527:Medulloblastoma / Q000150:complications* / Q000473:pathology* / Q000532:radiotherapy; D008569:Memory Disorders / Q000175:diagnosis / Q000209:etiology*; D009483:Neuropsychological Tests; D066127:White Matter / Q000473:pathology / Q000528:radiation effects