Cognitive function in primary progressive and transitional progressive multiple sclerosis: A controlled study with MRI correlates

Abstract

The relative rarity of primary progressive (PP) and transitional progressive (TP) multiple sclerosis has meant that little documentation of cognitive function in such patients is currently available. The aim of this study was to investigate the cognitive skills of patients with PP and TP multiple sclerosis relative to matched healthy controls, and to examine the relationship of this impairment to MRI parameters. Sixty-three patients (43 PP, 20 TP) were individually matched with healthy controls, who undertook the same cognitive tasks as the patient group. The neuropsychological assessment comprised Rao's brief repeatable battery, a reasoning test, and a measure of depression. Patients also underwent T1- and T2-weighted brain MRI. These patients were taken from a larger cohort (158 PP, 33 TP) in whom it had been demonstrated that the re were no significant differences between the mean scores of the PP and TP groups on any of the cognitive variables. The 63 patients were therefore taken as one group for comparison with the healthy controls. These patients performed significantly worse than the controls in tests of verbal memory, attention, verbal fluency and spatial reasoning. An impairment index was constructed and applied to the patient data. This correlated modestly with T2-lesion load (r = 0.45, P = 0.01), T1-hypointensity load (r = 0.45, P = 0.01) and cerebral volume (r = -0.35, P = 0.01). Thus, PP and TP multiple sclerosis patients demonstrate significant cognitive dysfunction when compared with matched healthy controls. The relationship between this impairment and MRI parameters is moderate, suggesting that cognitive dysfunction in PP and TP multiple sclerosis has a complex and multifactorial aetiology, which is not adequately explained by pathology as demonstrated on conventional MRI.

Evaluación neuropsicológica en 129 pacientes chilenos con esclerosis múltiple recurrente remitente previo a inicio de fármacos inmunomoduladores

“…Respecto del perfil de la afectación cognitiva de nuestros pacientes, observamos también lo referido por otros autores en cuanto a mayor compromiso de la memoria verbal, velocidad de procesamiento de la información y fluencia verbal [22][23][24][25][26][27] .…”

Functional MR Imaging Correlates of Neuropsychological Impairment in Primary-Progressive Multiple Sclerosis

“…7,17,25,26 For each patient, a cognitive impairment index was also computed as previously described. 7 Briefly, the cognitive impairment index 7 is a continuous variable obtained by a grading system applied to each patient's score on every cognitive test, dependent on the number of SDs below the mean normative value. These grades are then summed up across all variables to give an overall measure of cognitive dysfunction for each patient (composite cognitive score).…”

“…2 However, another clinical domain that is affected in Յ30% of patients with PPMS is cognition. 7 Previous fMRI studies of cognition in patients with MS with different disease phenotypes have shown that brain plasticity might have a role in maintaining a normal level of function. [8][9][10][11][12][13] However, the fMRI correlates of cognitive network dysfunction in patients with PPMS have not been investigated yet.…”

Neuropsychological Impairment in Systemic Lupus Erythematosus: A Comparison with Multiple Sclerosis

“…Most studies reveal that patients with MS are impaired in their ability to explicitly learn and subsequently recall new material, regardless of whether the material is verbal or visual (Amato et al 1995;Beatty et al 1989;Camp et al 1999;Grafman et al 1991;Minden 1990;Rao et al 1984;Ryan et al 1996). Two lines of research have been particularly influential in this regard.…”