title: Characterizing Clinical and MRI Dissociation in Patients with Multiple Sclerosis.
abstract: Two common approaches for measuring disease severity in multiple sclerosis (MS) are the clinical exam and brain magnetic resonance imaging (MRI) scan. Although most patients show similar disease severity on both measures, some patients have clinical/MRI dissociation.
  
  
  
  Subjects from a comprehensive care MS center who had a concurrent brain MRI, spinal cord MRI, clinical examination, and patient reported outcomes were classified into three groups based on the Expanded Disability Status Scale (EDSS) and cerebral T2 hyperintense lesion volume (T2LV). The first group was the low lesion load/high disability group (LL/HD) with T2LV < 2 ml and EDSS ≥ 3. The second group was the high lesion load/low disability group (HL/LD) with T2LV > 6 ml and EDSS ≤ 1.5. All remaining subjects were classified as not dissociated. The three groups were compared using regression techniques for unadjusted analyses and to adjust for age, disease duration, and gender.
  
  
  
  Twenty-two subjects were classified as LL/HD (4.1%; 95% CI: 2.6%, 6.2%), and 50 subjects were classified as HL/LD (9.4%; 95% CI: 7.0%, 12.2%). Subjects in the LL/HD group were more likely to have a progressive form of MS and had significantly lower physical quality of life in adjusted and unadjusted analysis. Subjects in HL/LD had significantly more gadolinium-enhancing lesions, and subjects in the LL/HD group had significantly more cervical spinal cord lesions.
  
  
  
  Our results indicate that dissociation may occur between physical disability and cerebral lesion volume in either direction in patients with MS. Type of MS, brain atrophy, and spinal cord lesions may help to bridge this dissociation.
authors.affiliation: Partners Multiple Sclerosis Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.
authors.forename: Brian C
authors.initials: BC
authors.lastname: Healy
authors.affiliation: Neuroimaging Research, MS Institute at Shepard Center, Atlanta, GA.
authors.forename: Guy J
authors.initials: GJ
authors.lastname: Buckle
authors.affiliation: Partners Multiple Sclerosis Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.
authors.forename: Eman N
authors.initials: EN
authors.lastname: Ali
authors.affiliation: Partners Multiple Sclerosis Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Egorova
authors.affiliation: Laboratory for Neuroimaging Research, Brigham and Women's Hospital, Boston, MA.
authors.forename: Fariha
authors.initials: F
authors.lastname: Khalid
authors.affiliation: Laboratory for Neuroimaging Research, Brigham and Women's Hospital, Boston, MA.
authors.forename: Shahamat
authors.initials: S
authors.lastname: Tauhid
authors.affiliation: Partners Multiple Sclerosis Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.
authors.forename: Bonnie I
authors.initials: BI
authors.lastname: Glanz
authors.affiliation: Partners Multiple Sclerosis Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.
authors.forename: Tanuja
authors.initials: T
authors.lastname: Chitnis
authors.affiliation: Center for Neurological Imaging, Brigham and Women's Hospital, Boston, MA.
authors.forename: Charles R G
authors.initials: CRG
authors.lastname: Guttmann
authors.affiliation: Partners Multiple Sclerosis Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.
authors.forename: Howard L
authors.initials: HL
authors.lastname: Weiner
authors.affiliation: Partners Multiple Sclerosis Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.|Laboratory for Neuroimaging Research, Brigham and Women's Hospital, Boston, MA.
authors.forename: Rohit
authors.initials: R
authors.lastname: Bakshi
mesh_terms: D000328:Adult; D001284:Atrophy / Q000000981:diagnostic imaging / Q000473:pathology; D001921:Brain / Q000000981:diagnostic imaging* / Q000473:pathology; D066193:Cervical Cord / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000000981:diagnostic imaging* / Q000473:pathology; D009929:Organ Size / Q000502:physiology; D011788:Quality of Life
keywords: brain atrophy; clinical/MRI dissociation; gadolinium-enhancing lesions; lesion volume; multiple sclerosis; quality of life; spinal cord lesions