Perfusion Magnetic Resonance Imaging Correlates of Neuropsychological Impairment in Multiple Sclerosis

Abstract

Although cognitive impairment is common in multiple sclerosis (MS), its pathophysiology is still poorly understood. Abnormalities of cerebral blood flow (CBF) have long been acknowledged in MS and advances in perfusion magnetic resonance imaging (MRI) allow for their assessment in vivo. We investigated the relationship between regional perfusion changes and neuropsychological (NP) dysfunctions in patients with relapsing-remitting and primary-progressive MS. Absolute CBF, cerebral blood volume (CBV) and mean transit time were measured in 32 MS patients and 11 healthy controls using dynamic susceptibility contrast-enhanced T2*-weighted MRI. A comprehensive NP test battery was administered to all patients. A mixed model analysis of covariance was performed for group comparisons in terms of perfusion measures in normal-appearing white matter (NAWM) and deep gray matter (GM). Pearson's correlations were used to describe the association of perfusion metrics with NP Z-scores. CBF and CBV values were significantly decreased in both NAWM and deep GM in MS patients compared with controls (P = 0.01). In all patients, deep GM CBF was significantly associated with Rey Complex Figure Test (RCFT)-Copy (r = 0.5; P = 0.001) and deep GM CBV and NAWM CBV were significantly associated with Color-Word Interference Inhibition Switching test (D-KEFSIS) (r = 0.4; P = 0.008 and r = 0.4; P = 0.02). However, the only associations that remained significant after Bonferroni correction were between deep GM CBF and RCFT-Copy (P = 0.006), and deep GM CBV and D-KEFSIS (P = 0.04). Our results suggest a role for tissue perfusion impairment in NP dysfunction in MS. Large-scale studies are needed to characterize better this association.

Decreased Frontal Lobe Gray Matter Perfusion in Cognitively Impaired Patients with Secondary-Progressive Multiple Sclerosis Detected by the Bookend Technique

“…25 While we did not corroborate their results in terms of our anterior and posterior basal ganglia regions, that study did not examine cortical GM, so there is no basis for comparison with respect to our frontal lobe findings. Paulesu et al 26 examined cerebral metabolic rates in patients with MS with memory impairment using PET imaging and identified significantly diminished metabolism in their bilateral prefrontal cortices compared with patients with MS without memory impairment.…”

“…There has been a single prior study that examined cerebral perfusion in cognitively impaired patients with MS. 25 Inglese et al reported significant correlations between subcortical GM CBF and the Rey Complex Figure Test score, and subcortical GM CBV and the Delis-Kaplan Executive Function System score. 25 While we did not corroborate their results in terms of our anterior and posterior basal ganglia regions, that study did not examine cortical GM, so there is no basis for comparison with respect to our frontal lobe findings.…”

Cerebral Arterial Bolus Arrival Time is Prolonged in Multiple Sclerosis and Associated with Disability

“…15,35,36 The differences may be due to patient selection. Patients in our study all had relapsing-remitting MS with a higher median EDSS with similar disease duration compared with studies where a reduction in CBF was reported.…”

Avaliação das funções cognitivas de atenção, memória e percepção em pacientes com esclerose múltipla

“…A comparação dos resultados relativos à Figura Complexa de Rey-Osterrieth, com outros estudos não foi possível, por diferença de metodologia empregada. A maioria das pesquisas utilizando esse teste era tipo caso-controle, não informava o percentual de pacientes com EM e comprometimento de memória de trabalho ou de curto prazo e tinha análise estatística por regressão multivariada ou correlação (Inglese et al, 2008;Schulz et al, 2006). O percentual de perda de memória de curto prazo avaliada pelo teste RAVLT igual a 17,8% desta pesquisa foi menor que os 33% referidos por Schulz et al (2006), usando o mesmo teste, embora se deva considerar que o padrão não foi construído para a população brasileira.…”

“…Ressaltaram que a perda de memó-ria de curto prazo deve ser valorizada no tratamento da EM, porque compromete muito o desempenho das ativi-dades diárias e reduz a qualidade de vida. Inglese et al (2008), também empregando esse instrumento, informaram que 50% dos pacientes tinham perda de memória de curto prazo. O percentual de pacientes da presente pesquisa com prejuízo dessa memória, avaliada pelo RAVLT, foi menor que os 33,3% relatados por Negreiros et al (2008), testando 54 pacientes na forma clínica surto-remissão, mas teve em comum a identificação de uma curva de aprendizagem que não se associou à gravidade de esclerose múltipla, avaliada pelo EDSS.…”