Regional hippocampal involvement and cognitive impairment in pediatric multiple sclerosis.
OBJECTIVE
We assessed global and regional hippocampal volume abnormalities in pediatric multiple sclerosis (MS) patients and their correlations with clinical, neuropsychological and magnetic resonance imaging metrics.


METHODS
From 53 pediatric MS patients and 18 healthy controls, global hippocampal volume was computed using a manual tracing procedure. Regional hippocampal volume modifications were assessed using a radial mapping analysis. MS patients with abnormal performance in three or more tests of a neuropsychological battery for children were classified as cognitively impaired.


RESULTS
Global hippocampal volume was reduced in MS patients compared with controls, but did not correlate with clinical, neuropsychological and magnetic resonance imaging measures. Compared to controls, MS patients experienced bilateral radial atrophy of the cornu ammonis, subiculum and dentate gyrus subfields as well as radial hypertrophy of the dentate gyrus subfield. Regional hippocampal volume modifications correlated with brain T2 lesion volume as well as attention and language abilities. Global hippocampal volume did not differ between cognitively impaired (n=12) and cognitively preserved MS patients. Compared to cognitively preserved, cognitively impaired MS patients had atrophy of the subiculum and dentate gyrus subfields of the right hippocampus.


CONCLUSIONS
Hippocampal subregions have different vulnerability to damage in pediatric MS. Regional rather than global hippocampal involvement contributes to global cognitive impairment as well as to deficits of selected cognitive tests.
Neuroimaging Research Unit, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Italy/Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Italy.
Maria A
MA
Rocca
Neuroimaging Research Unit, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Italy/Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Italy.
Maria E
ME
Morelli
Department of Neurology, University of Florence, Italy.
Maria P
MP
Amato
Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Italy.
Lucia
L
Moiola
Multiple Sclerosis Center, Ospedale di Gallarate, Italy.
Angelo
A
Ghezzi
Department of Child Neurology and Psychiatry, C. Mondino National Neurological Institute, Pavia, Italy and Brain and Behaviour Department, University of Pavia, Pavia, Italy.
Pierangelo
P
Veggiotti
Multiple Sclerosis Center, Spedali Civili of Brescia, Italy.
Ruggero
R
Capra
Neuroimaging Research Unit, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Italy.
Elisabetta
E
Pagani
Department of Neurology, University of Florence, Italy.
Emilio
E
Portaccio
Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Italy.
Agnese
A
Fiorino
Multiple Sclerosis Center, Ospedale di Gallarate, Italy.
Lorena
L
Pippolo
Department of Child Neurology and Psychiatry, C. Mondino National Neurological Institute, Pavia, Italy and Brain and Behaviour Department, University of Pavia, Pavia, Italy.
Maria C
MC
Pera
Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Italy.
Giancarlo
G
Comi
Department of Neuroradiology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Italy.
Andrea
A
Falini
Neuroimaging Research Unit, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Italy/Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Italy filippi.massimo@hsr.it.
Massimo
M
Filippi
D000293:Adolescent; D001284:Atrophy; D001931:Brain Mapping; D002648:Child; D003072:Cognition Disorders / Q000000981:diagnostic imaging* / Q000209:etiology / Q000473:pathology; D005260:Female; D006624:Hippocampus / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009103:Multiple Sclerosis / Q000000981:diagnostic imaging* / Q000473:pathology
Hippocampus; cognition; magnetic resonance imaging; pediatric multiple sclerosis; radial mapping