Thursday, 3 September 2015

To shrink or not to shrink what will I remember

Rocca MA, Morelli ME, Amato MP, Moiola L, Ghezzi A, Veggiotti P, Capra R, Pagani E, Portaccio E, Fiorino A, Pippolo L, Pera MC, Comi G, Falini A, Filippi MRegional hippocampal involvement and cognitive impairment in paediatric multiple sclerosis.Mult Scler. 2015 Aug. pii: 1352458515598569. [Epub ahead of print]

OBJECTIVES: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 paediatric 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 paediatric MS. Regional rather than global hippocampal involvement contributes to global cognitive impairment as well as to deficits of selected cognitive tests.

In vivo evidence of hippocampal dentate gyrus expansion in multiple sclerosis. Rocca MA, Longoni G, Pagani E, Boffa G, Colombo B, Rodegher M, Martino G, Falini A, Comi G, Filippi M.Hum Brain Mapp. 2015 Aug. doi: 10.1002/hbm.22946. [Epub ahead of print]

Using MR-based radial mapping, we assessed morphological alterations of the hippocampal dentate gyrus (DG) in patients with relapse-onsetmultiple sclerosis (MS). We analyzed different stages of the disease and the association of DG alterations with hippocampal-related cognitive functions. Using high-resolution morphological imaging, hippocampal radial mapping analysis was performed in 28 relapsing-remitting (RR), 34 secondary progressive, and 26 benign MS patients and 28 healthy controls (HC). Between-groups differences of DG radial distance (from surface points to the central core of the hippocampus) and correlations with clinical, neuropsychological, and radiological measures were evaluated using surface-based mesh modeling. Compared with HC, all MS clinical phenotypes revealed a larger radial distance of the DG, which was more marked on the left side. Radial distance enlargement was more pronounced in RRMS patients compared with the other disease clinical phenotypes and was inversely correlated to disease duration. Radial distance enlargement was correlated with higher T2 lesion volume and a better cognitive performance in RRMS and with a poor cognitive performance in secondary progressive and benign MS patients. Surface expansion of the DG might represent an inflammation-induced neurogenic (reactive) process of the subgranular zone of the hippocampus primarily aimed at rescuing the functional competence of hippocampal circuitry.

To shrink or not to shrink that is the question? 

The hippocampus is where your short term memory is formed, which facts will you put there, left or right, big or small?

Calabrese M, Reynolds R, Magliozzi R, Castellaro M, Morra A, Scalfari A, Farina G, Romualdi C, Gajofatto A, Pitteri M, Benedetti MD, Monaco S.Regional Distribution and Evolution of Gray Matter Damage in Different Populations of Multiple Sclerosis Patients. PLoS One. 2015 Aug;10(8):e0135428.

BACKGROUND:Both gray-matter (GM) atrophy and lesions occur from the earliest stages of Multiple Sclerosis (MS) and are one of the major determinants of long-term clinical outcomes. Nevertheless, the relationship between focal and diffuse GM damage has not been clarified yet. Here we investigate the regional distribution and temporal evolution of cortical thinning and how it is influenced by the local appearance of new GM lesions at different stages of the disease in different populations of MS patients.
METHODS:We studied twenty MS patients with clinically isolated syndrome (CIS), 27 with early relapsing-remitting MS (RRMS, disease duration <5 years), 29 with late RRMS (disease duration ≥ 5 years) and 20 with secondary-progressive MS (SPMS). The distribution and evolution of regional cortical thickness and GM lesions were assessed during 5-year follow-up.
RESULTS:The results showed that new lesions appeared more frequently in hippocampus and parahippocampal gyri (9.1%), insula (8.9%), cingulate cortex (8.3%), superior frontal gyrus (8.1%), and cerebellum (6.5%). The aforementioned regions showed the greatest reduction in thickness/volume, although (several) differences were observed across subgroups. The correlation between the appearance of new cortical lesions and cortical thinning was stronger in CIS (r2 = 50.0, p<0.001) and in early RRMS (r2 = 52.3, p<0.001), compared to late RRMS (r2 = 25.5, p<0.001) and SPMS (r2 = 6.3, p = 0.133).
CONCLUSIONS: We conclude that GM atrophy and lesions appear to be different signatures of cortical disease in MS having in common overlapping spatio-temporal distribution patterns. However, the correlation between focal and diffuse damage is only moderate and more evident in the early phase of the disease.

3D Regional map of the frequency of the appearance of new grey matter lesions during the 5-year follow up in the whole group and in the different MS subsets.

"The development of regional cortical thinning was not homogeneous across different MS groups. The reduction of CTh and volume of the hippocampus and the parahippocampal gyrus, the insula, and the cingulate cortex were particularly severe in CIS and early RRMS patients whereas in late RRMS and SPMS cortical thinning and volume loss were significantly greater in the precentral gyrus, the postcentral gyrus, and the cerebellum"

To shrink or is it the left gets bigger or is it the right shrinks so the left is bigger.


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