ORIGINAL COMMUNICATION

Identification of cortical lesions using DIR and FLAIR in earlystages of multiple sclerosis

Pierre Kolber1• Swantje Montag1

• Vinzenz Fleischer1• Felix Luessi1 •

Janine Wilting1• Joachim Gawehn2

• Adriane Groger1• Frauke Zipp1

Received: 13 February 2015 / Revised: 25 March 2015 / Accepted: 26 March 2015

� Springer-Verlag Berlin Heidelberg 2015

Abstract The use of non-routine MRI sequences such as

DIR has highlighted the role of gray matter (GM) pathol-

ogy in multiple sclerosis (MS). The aim of this study was to

assess the detection and relevance of cortical lesions (CLs)

using MRI in early (\5 years) MS patients. 3D DIR and

3D FLAIR images at 3T from 122 patients [93 relapsing–

remitting MS (RRMS), 29 clinically isolated syndrome

(CIS)] were scored for CLs by two blinded readers. Pa-

tients were divided into two groups depending on the

presence or absence of CLs. For FLAIR, 51 CLs were

identified, of which 13 were purely intracortical and 38

mixed CLs; for DIR, this was 60 in total and 16 and 44,

respectively. In both groups, there was no difference in GM

fraction. Neuropsychological testing was performed for a

subgroup of 66 patients. In 22.1 % of patients CLs were

identified. The number of CLs revealed an association with

lower working memory scores and semantical word flu-

ency. Overall, CLs imaged with 3D FLAIR and 3D DIR

sequences are found more frequently in RRMS patients

than CIS and may also be a correlate for mild neuropsy-

chological pathology.

Keywords Multiple sclerosis � Cortical lesions �Magnetic resonance imaging � Neuropsychological testing

Introduction

Multiple sclerosis (MS), one of the most common chronic

neuroinflammatory diseases and causes of disability in

young adults, is traditionally considered to be caused by

demyelination in white matter (WM); however, the role of

gray matter (GM) is becoming increasingly prominent.

Although described in anatomopathological studies over a

century ago [1], cortical pathology only recently returned

to the spotlight of MS research as a result of specialized

MRI sequences not used in clinical routine. With con-

ventional T2-weighted sequences, GM lesions are less

visible, but by nulling the signal from the CSF and WM,

double inversion recovery (DIR) allows better detection of

cortical lesions (CLs). Using this sequence, CLs have even

been reported to potentially precede demyelination of WM

[2–4], the neuroinflammatory [5] and neurodegenerative

[6] processes that characterize all MS phenotypes and

occur early in the disease [7]. However, controversy re-

mains about whether DIR should be adopted in MS clin-

ical routine [8–10]. Other specialized sequences such as

phase-sensitive inversion recovery (PSIR) have been

shown to offer improvements over DIR in evaluating

cortical pathology and offer complementary information

[11–13].

Recent studies indicate an association of CL with clin-

ical and cognitive impairment [14–19] in relapsing–

remitting (RRMS) and progressive MS patients. The aim of

this study was to evaluate the frequency and clinical impact

of CLs in patients early in the disease. To ensure an ac-

curate determination of CL load, we independently

A. Groger and F. Zipp contributed equally.

& Frauke Zipp

frauke.zipp@unimedizin-mainz.de

1 Department of Neurology, Neuroimaging Center (NIC) of the

Focus Program Translational Neuroscience (FTN),

University Medical Center of the Johannes Gutenberg-

University Mainz, Langenbeckstraße 1, 55131 Mainz,

Germany

2 Institute of Neuroradiology, University Medical Center of the

Johannes Gutenberg-University Mainz, Mainz, Germany

123

J Neurol

DOI 10.1007/s00415-015-7724-5

assessed both 3D DIR and 3D fluid-attenuated inversion

recovery (FLAIR) sequences, considering that they provide

complementary information [13, 20, 21] and were both

available as part of our standard MRI protocol for MS. This

was performed for a large cohort of CIS and early RRMS

patients and the results were then correlated against clinical

and cognitive measures.

Materials and methods

Patients

This retrospective, single-center analysis was performed on

122 patients (29 CIS, 93 RRMS) diagnosed using the

McDonald criteria [22] with a median age of 32 years

(18–63 years), female/male ratio of 2.3, median disease

duration of 1.7 years (0–5 years), median number of re-

lapses (NOR) of 2 (1–6) and median Expanded Disability

Status Scale (EDSS) [23] of 1.0 (0–4.0). At the time of

MRI, 37 patients were being treated with interferon-beta

(IFNb), 21 with glatiramer acetate (GA), 4 with oral im-

munomodulating drugs [teriflunomide (TF) or dimethyl

fumarate (DF)], 15 with monthly natalizumab infusions

(NA) and 45 subjects were not being treated (NT). Nine of

the 29 CIS patients converted to RRMS within 2 years of

diagnosis. Patients with a disease duration exceeding

5 years were not included to establish a cohort of early MS

patients. Other exclusion criteria were being under

18 years of age or having a chronic progressive form of

MS (SPMS, PPMS). Detailed demographic data are shown

in Table 1.

Table 1 Demographic data Variable Total (n = 122) CIS (n = 29) RRMS (n = 93) p value

Gender

Female (n) 85 18 67 0.308c

Male (n) 37 11 26 0.308c

Disease type

CIS (n) 29 – – –

RRMS (n) 93 – – –

Age (years)

Median (range) 31.75 (18–63) 32.50 (19–56) 30.50 (18–63) 0.691b

EDSS

Median (range) 1.0 (0.0–4.0) 1.0 (0.0–3.0) 1.5 (0.0–4.0) 0.389b

NOR

Median (range) 2 (1–6) 1 2 (1–6) \0.0001b,*

DD (years)

Median (range) 1.65 (0.00–5.00) 0.60 (0.00–4.00) 2.00 (0.00–5.00) \0.0001b,*

LV (ml)

Median (range) 1.82 (0.00–45.36) 1.27 (0.10–19.47) 2.05 (0.00–45.36) 0.127b

GMF

Mean ± SD 0.44 ± 0.03 0.44 ± 0.03 0.44 ± 0.03 0.837a

Therapy

Interferon-beta 37 9 28 0.924c

Glatiramer acetate 21 3 18 0.262c

Teriflunomide 2 1 1 0.380c

Dimethyl fumarate 2 0 2 0.426c

Natalizumab 15 0 15 0.026c,*

Other/none 45 16 29 0.019c,*

CIS clinically isolated syndrome, RRMS relapsing–remitting multiple sclerosis, GA? group of subjects

treated with glatiramer acetate, GA- group of subjects not treated with glatiramer acetate, CL? group with

cortical lesions, CL- group without cortical lesions, EDSS Expanded Disability Status Scale, DD disease

duration, NOR number of relapses, LV lesion volume, GMF gray matter fraction

* Statistically significanta Derived from t testb Derived from Mann–Whitney U testc Derived from Chi-square test

J Neurol

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All patients gave their written informed consent to ex-

aminations before participating in this study, which was

approved by the local ethics committee and adhered to

institutional guidelines in accordance with the Declaration

of Helsinki.

For a subgroup of 66 of the patients, we also had results

from neuropsychological testing, including measurements

of information processing speed [Symbol Digit Modality

Test (SDMT), Trail Making Test (TMT-A)], working

memory [Paced Auditory Serial Addition Test (PASAT)],

visual short-term memory [block span of the Wechsler

Memory Scale-Revised (WMS-R)], learning and memory

[Verbal Learning and Memory Test (VLMT), with

VLMT_verbal for verbal learning, VLMT_global for

global learning and VLMT_longterm for longterm learning

capacity], alertness [Tests of Attentional Performance

(TAP)––subtest Alertness], cognitive flexibility (TMT-B)

and word fluency [Regensburger Word Fluency Test

(RWT), with RWT_lexical for lexical word fluency and

RWT_semantical for semantical word fluency]. Neu-

ropsychological data are given as z-scores.

MR image acquisition

All patients underwent an MRI examination. Measure-

ments were performed on a 3T MR scanner (Magnetom

Tim Trio, Siemens Healthcare, Erlangen, Germany) with a

32-channel head coil. The following sequences were used:

1. Sagittal 3D fluid-attenuated inversion recovery

(FLAIR): repetition time (TR) = 5000 ms, echo time

(TE) = 388 ms, inversion time (TI) = 1800 ms, turbo

factor = 141, echo train length = 848 ms, field of

view (FOV) = 256 9 256 mm2, matrix size = 256 9

256, slab thickness = 192 mm, voxel size = 1 9 1 9

1 mm3, optimized variable flip angle, band-

width = 781 Hz/Px.

2. Sagittal 3D double inversion recovery (DIR): repeti-

tion time (TR) = 7500 ms, echo time (TE) = 307 ms,

inversion time (TI) = 3000 ms, turbo factor = 216,

echo train length = 657 ms, field of view (FOV) =

256 9 256 mm2, matrix size = 256 9 256, slab

thickness = 192 mm, voxel size = 1 9 1 9 1 mm3,

optimized variable flip angle, bandwidth = 781 Hz/

Px.

3. Sagittal 3D T1-weighted magnetization prepared rapid

gradient echo (MP-RAGE): repetition time

(TR) = 1900 ms, echo time (TE) = 2.52 ms, inver-

sion time (TI) = 900 ms, field of view (FOV) =

256 9 256 mm2, matrix size = 256 9 256, slab

thickness = 192 mm, voxel size = 1 9 1 9 1 mm3,

flip angle = 9�, bandwidth = 170 Hz/Px.

Image analysis and group definition

Given that the sensitivity and specificity of DIR are low

[11, 21, 24, 25] (signal intensity variations or vessel hy-

perintensities) and possible misinterpretation is common if

used alone without other confirmatory sequences [21], we

used a second T2-weighted MR sequence, in this case 3D-

FLAIR, to confirm the presence of lesions. FLAIR se-

quences are well established in clinical practice for the

diagnosis of MS and T2-weighted sequences are included

in the revised McDonald criteria [22]. DIR and FLAIR

were viewed (in groups and several days apart to avoid any

bias) by two raters with respect to CL load, blinded to the

outcome of the other sequence and the clinical features of

the patients.

For scoring, both raters followed the international

criteria proposed by Geurts et al. [21]. CLs were classi-

fied by their topographic location (infra- and supratento-

rial lesions) (Fig. 1c) and their relation to the cortical

band (purely intracortical lesions or mixed white–gray

matter lesions). Intracortical lesions were confined ex-

clusively to the cortical ribbon, and did not encompass

any subcortical WM (Fig. 1a, b); mixed cortical lesions

were defined as lesions that overlap both the cortical

ribbon and the WM (Fig. 1d). Patients were positively

scored for CL (CL?) if both raters identified lesions in

both scans, and otherwise negatively scored (CL-). The

number of patients with CLs as well as the total number

of CLs was counted.

MRI post-processing

For lesion and tissue segmentation, the statistical parameter

mapping (SPM8) software (http://www.fil.ion.ucl.ac.uk/

spm) with lesion segmentation toolbox (LST) (http://www.

applied-statistics.de/lst.html) and VBM8 toolbox (http://

dbm.neuro.uni-jena.de/vbm/) was used.

First, using LST, 3D FLAIR images were co-registered

to 3D MP-RAGE images and bias corrected. After partial

volume estimate (PVE) label estimation, lesion segmenta-

tion was performed with an optimal threshold value

(j = 0.1) for the lesion growth algorithm [26]. Subse-

quently, the filled MP-RAGE images were segmented into

GM, WM, and cerebrospinal fluid (CSF). With regard to

measuring brain atrophy [27, 28], GM results were asses-

sed as fractions of total brain volume.

Statistics

Statistical analysis was performed using SPSS Statistics,

Version 22.0 (IBM, Chicago, Illinois, United States of

America). The Kolmogorov–Smirnov test was used to

J Neurol

123

verify a normal distribution of data. Means with standard

deviations (SD) as well as medians with ranges were cal-

culated. Between-group differences of demographic and

MRI features were evaluated with the t test, Mann–Whit-

ney U test and Chi-square test, respectively. The Spearman

rank and Pearson correlation tests were used to determine

correlations between the variables. The significance level

was set to p \ 0.05.

Results

Using DIR images, we identified 27 patients with C1 CL,

representing 22.1 % of our cohort. In total, 60 CL (16 in-

tracortical, 44 mixed lesions) were counted (Table 2).

After using FLAIR images, we confirmed the 27 subjects

with CLs. However, only 51 lesions were counted, of

which 13 were purely intracortical and 38 mixed CLs.

These 27 patients were defined as the group positively

scored for CLs (CL?).

We detected most CLs in supratentorial GM, with 49

CLs in DIR (35 mixed and 14 intracortical) and 41 CLs in

FLAIR (32 mixed and 9 intracortical). In infratentorial

GM, DIR and FLAIR images revealed a similar number of

CLs (11 and 10, respectively) (Table 2). Altogether, with

FLAIR images we were able to detect 85 % of the CLs

seen in DIR.

Clinical data (disease duration, number of relapses,

EDSS, gender and comorbidities) as well as GMF and LV

did not differ between CL? and CL- (Table 1). We found

clear differences between the number of patients with and

without CLs being treated with GA (p = 0.035) and also

between those with the CIS phenotype (p = 0.006). Fur-

ther, the number of CLs (counted in DIR or in FLAIR

images) did not correlate with these clinical and MRI data

(Table 3).

Fig. 1 Examples of cortical

lesions. a Intracortical lesion

(DIR left, FLAIR right). b U-

shaped cortical lesion in DIR

(sagittal view left, axial view

right). c Infratentorial cortical

lesion (DIR left, FLAIR right).

d Mixed gray–white matter

lesion in DIR

J Neurol

123

Ta

ble

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fter

inte

r-re

ader

con

firm

atio

n(F

LA

IRan

dD

IR)

To

tal

(n=

12

2)

CIS

(n=

29

)

RR

MS

(n=

93

)

pv

alu

ea,c

GA

?

(n=

21

)

GA

-

(n=

10

1)

pv

alu

ea,d

To

tal

(n=

12

2)

CIS

(n=

29

)

RR

MS

(n=

93

)

pv

alu

ea,c

GA

?

(n=

21

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GA

-

(n=

10

1)

pv

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Les

ion

count

(num

ber

of

CL

)

ST

mix

edC

L35

629

0.3

99

035

0.0

32*

32

230

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53

032

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intr

acort

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CL

14

311

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81

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91

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09

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58

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21

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J Neurol

123

Table 3 Group comparison (CL? vs CL-): clinical impact of cortical lesions in early phase of the disease

Variable CL? (n = 27) CL- (n = 95) p value Correlation with number of CL

in CL? group

p value

Gender

Female (n) 16 69 0.182c

Male (n) 11 26 0.182c

Disease type

CIS (n) 1 28 0.006c,*

RRMS (n) 26 67 0.006c,*

Age (years)

Median (range) 32.90 (19–63) 31.10 (18–63) 0.953b

EDSS

Median (range) 1.0 (0.0–3.5) 1.5 (0.0–4.0) 0.227b -0.301 0.127

NOR

Median (range) 2 (1–6) 1 (1–5) \0.0001b,* -0.163 0.416

DD (years)

Median (range) 2.00 (0.00–5.00) 1.60 (0.00–5.00) 0.269b 0.312 0.114

LV (ml)

Median (range) 2.05 (0.24–32.99) 1.66 (0.00–45.36) 0.246b 0.133 0.509

GMF

Mean ± SD 0.45 ± 0.04 0.44 ± 0.03 0.805a 0.038 0.850

Therapy

Interferon-beta 10 27 0.390c

Glatiramer acetate 1 20 0.035c,*

Teriflunomide 0 2 0.447c

Dimethyl fumarate 1 1 0.338c

Natalizumab 4 11 0.651c

Other/none 11 34 0.638c

Cognitive tests (n = 66) CL? (n = 18) CL- (n = 46) p value Correlation with number of CL p value

TAP

Mean ± SD, n 0.09 ± 0.59, 18 0.00 ± 0.90, 46 0.647a 0.085 0.738

SDMT

Mean ± SD, n -0.61 ± 1.33, 18 -0.19 ± 1.03, 45 0.268a 0.462 0.054

PASAT

Median (range), n -0.17 (-3.00 to 1.31), 18 -0.14 (-3.00 to 1.31), 46 0.321b 0.495 0.037*

WMS-R

Median (range), n 0.15 (-1.30 to 1.50), 18 0.20 (-2.00 to 2.40), 44 0.950b 0.096 0.706

VLMT_verbal

Median (range), n -0.37 (-2.23 to 1.99), 18 0.12 (-1.62 to 2.23), 45 0.062b 0.294 0.236

VLMT_global

Mean ± SD, n -0.21 ± 0.99, 18 0.18 ± 0.90, 45 0.140a 0.134 0.597

VLMT_longterm

Median (range), n -0.34 (-4.57 to 0.83), 18 0.23 (-2.57 to 1.43), 45 0.088b 0.209 0.406

TMT_A

Median (range), n -0.48 (-2.50 to 2.20), 18 -0.23 (-11.11 to 1.63), 46 0.585b 0.310 0.210

TMT_B

Median (range), n -0.10 (-2.50 to 1.20), 18 0.16 (-3.00 to 2.30), 46 0.988b 0.165 0.514

J Neurol

123

In the subgroup of 66 patients (18 CL? and 48 CL-) for

whom we had neuropsychological test results, all z-scores

were in the same range as those of healthy controls, indi-

cating that there was no cognitive impairment. No differ-

ences between the CL? and CL- groups were found in the

results of the cognitive tests (Table 1). In the CL? group, a

significant correlation was found between the total number

of CLs in FLAIR and the RWT semantic word fluency

(p = 0.035), as well as with the PASAT working memory

(p = 0.037) (Table 3).

Discussion

Patient-based studies with the goal of translating ex-

perimental findings to the clinic are necessary to advance

the understanding and treatment of multiple sclerosis [29].

Among other challenges facing research of this disease is

that the meaning and processes of neuronal compartment

pathology are still not fully understood [30]. One approach

to address this gap in our knowledge is to employ MRI

sequences such as DIR that are not routinely used in

clinical practice to unravel the overall role of GM pathol-

ogy in the disease [31]. CLs are difficult to detect, but have

been reported to be associated with disability and a more

severe disease course [32]. Studies have shown that CLs

are present in early stages of MS [2], but that their im-

portance increases with disease progression (EDSS) [15].

However, both the frequency and specific role of these

lesions are still under debate. These studies have focused

on small or rather heterogeneous cohorts, including various

disease phenotypes and patients across the whole course of

the disease. Our study aimed to evaluate the frequency and

clinical impact of CLs in a large disease cohort consisting

of only RRMS and CIS patients in very early stages of the

disease, namely less than 5-year disease duration.

The most common type of CL is located on the subpial

layer of the cortex [33, 34] and often can only be seen

postmortem or with magnetic field strengths greater than

3T [13]. Also, different MR sequences can affect the

identification of lesions, with some juxtacortical lesions

assigned in FLAIR images being interpreted as mixed GM/

WM lesions in DIR due to poor definition of lesion

boundaries [11] (Fig. 2). Artifacts due to magnetic field

inhomogeneities or vessel hyperintensities are further

causes of misinterpretation. Additionally, even when fol-

lowing the international recommendations on lesion scor-

ing, an agreement of only 19 % of the CLs scored was

reached between experts [21], so that DIR, despite its

sensitivity for CL scoring, may have a rather low speci-

ficity. To ensure reliable findings [24, 25] and to minimize

any false positives resulting from artifacts in DIR images,

two blinded readers viewed both 3D DIR and 3D FLAIR

images to assess them for the presence of CLs; only in

cases where the readers were in consensus were the pa-

tients defined as having CLs. The use of additional T2- or

T1-weighted MRI sequences to classify a cortical lesion

[13, 35] follows current recommendations [21] and has also

been discussed recently in smaller studies [36].

In 122 patients (93 RRMS, 29 CIS) with a median dis-

ease duration of 1.5 years, we detected CLs in 22.1 % of

the patients (28.0 % RRMS, 3.4 % CIS). We did not find

major clinical differences between patients with and

without cortical lesions, suggesting that these lesions may

be less frequent in early stages of RRMS than previously

thought [15, 17, 32]. In the neuropsychological analysis

Table 3 continued

Cognitive tests (n = 66) CL? (n = 18) CL- (n = 46) p value Correlation with number of CL p value

RWT_lexical

Median (range), n -0.15 (-2.50 to 1.50), 18 0.25 (-1.60 to 1.60), 44 0.629b 0.233 0.352

RWT_semantical

Mean ± SD, n -0.43 ± 1.03, 17 -0.32 ± 0.90, 41 0.678a 0.514 0.035*

CIS clinically isolated syndrome, RRMS relapsing–remitting multiple sclerosis, GA ? group of subjects treated with glatiramer acetate, GA -

group of subjects not treated with glatiramer acetate, CL ? group with cortical lesions, CL - group without cortical lesions, EDSS Expanded

Disability Status Scale, DD disease duration, NOR number of relapses, LV lesion volume, GMF gray matter fraction, TAP tests of attentional

performance, SDMT Symbol Digit Modality Test for information processing speed, PASAT Paced Auditory Serial Addition Test, WMS-

R Wechsler Memory Scale-Revised, VLMT_verbal Verbal Learning and Memory Test for verbal learning, VLMT_global Verbal Learning and

Memory Test for global learning, VLMT_longterm Verbal Learning and Memory Test for longterm learning capacity, TMT_A Trail Making Test

for information processing speed, TMT_B Trail Making Test for cognitive flexibility, RWT_lexical Regensburger Word Fluency Test for lexical

word fluency, RWT_semantical Regensburger Word Fluency Test for semantical word fluency

* Statistically significanta Derived from t testb Derived from Mann–Whitney U testc Derived from Chi-square test

J Neurol

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performed on a subgroup of 66 patients, we found a cor-

relation between the number of CLs and the semantic word

fluency (RWT), as well as working memory (PASAT),

suggesting that GM pathology in MS starts with structural

or functional alterations in the left frontal lobe of the brain.

In a study on CL and WM lesions in a pediatric form of MS

[37], investigators found that CL volume and GM volume

were the same in both cognitively impaired and cognitively

preserved children, but that WM volume was significantly

decreased in patients with cognitive deficits. However, in

recent studies on adults with MS [17, 18], GM pathology

[38] has been associated with a bad cognitive outcome,

which is in agreement with our findings.

Interestingly, we note that fewer subjects treated with

GA were scored positively for CL and had a lower CL

count than those receiving other therapies. However, fur-

ther studies with more subjects must be performed to

conclude whether this finding might be of significance.

In contrast to earlier studies, we observed fewer CLs

than expected. Calabrese et al. [14] reported that 64 % of

RRMS patients with a disease duration up to 13 years

(mean disease duration of 5 years) and mean EDSS of 2

exhibited CLs as identified by 1.5T MRI, and 36 % of CIS

patients with mean disease duration of 0.8 years and EDSS

of 1.2 (up to 3.5). We found only 28 % of patients had CLs

in the RRMS group with a median disease duration of less

than 2 years and not exceeding 5 years and identified only

3 % having CLs in our group of CIS patients, whose dis-

ease duration did not exceed 4 years. These differences

could be due to the shorter disease duration of our cohort as

well as the different methodologies employed (2D FLAIR

and 2D DIR at 1.5T versus 3D FLAIR and 3D DIR at 3T;

different voxel size).

Based on the results presented here, we agree with

Chard et al. [9].that the identification of CLs with DIR is

not yet suitable to allow clear-cut conclusions concerning

disease severity or overall ‘‘neurodegeneration’’ in clinical

practice.

Although the use of DIR is relatively widespread, this

study shows that it remains of limited value in the de-

tection of CLs in MS. This finding is in line with other

studies [11, 24, 25] and the current recommendations

[21], which specify that DIR should be used with other

T1- or T2-weighted MRI sequences to assure reliable

findings. 3D FLAIR at 3T has a similar contrast for

cortical lesions and a higher signal-to-noise ratio than

DIR. Furthermore, DIR is very time consuming and has a

high specific absorption rate. Therefore, for high-field

MRI, it seems that 3D-FLAIR might be the best sequence

to study cortical pathology lesion [13, 35]. The more

recently used PSIR sequence permits better detection of

CLs than DIR, which may further make the utility of DIR

sequences less relevant [11, 12]. Although it has been

previously reported that the number of CLs increases over

time and that there is an association with disability in MS,

in our early cohort we found no correlation between CLs

and EDSS or NOR. However, a correlation was found

between the number of CLs and changes in cognitive

function in word fluency and working memory, suggest-

ing that cognitive functions are the first to be altered by

GM pathology. Furthermore, a recent report on RIS pa-

tients identified 40 % as having CLs using DIR [39],

which in light of the difference we observed between CIS

and RRMS CL frequency must be interpreted either as a

different underlying pathology or erroneous CL identifi-

cation using DIR images alone.

A limitation of our study is the cross-sectional design as

well as detailed neuropsychological testing being available

for only a subgroup of patients. Further prospective in-

vestigations focusing on early phase MS patients including

a detailed analysis of the lesion distribution should increase

our knowledge of the early disease.

In conclusion, using 3D DIR and 3D FLAIR images in

CIS and RRMS, we present evidence that CLs, although

already present, are less common in early phases of the

disease than previously expected. Despite a clear difference

between CIS and MS, no relation with other parameters

such as GMF, which characterizes the neuronal compart-

ment, or with disease severity was detected at this early

disease stage, indicating that the presence and number of

CLs may not be a relevant indicator of early neurodegen-

eration in MS.

Fig. 2 Juxtacortical lesion

scored as a mixed gray–white

matter lesion. The DIR image is

shown in the left panel and the

FLAIR in the right

J Neurol

123

Acknowledgments F.Z. is grateful for financial support from the

German Multiple Sclerosis Competence Network (KKNMS, Project

B7.3) funded by the Federal Ministry for Education and Research

(BMBF).

Conflicts of interest Pierre Kolber reports no conflicts of interest

and financial disclosures. Swantje Montag reports no conflicts of in-

terest and financial disclosures. Dr. Vinzenz Fleischer reports no

conflicts of interest and financial disclosures. Dr. Felix Lussi reports

no conflicts of interest and financial disclosures. Janine Wilting re-

ports no conflicts of interest and financial disclosures. Dr. Joachim

Gawehn reports no conflicts of interest and financial disclosures. Dr.

Adriane Groger reports no conflicts of interest and financial disclo-

sures. Dr. Frauke Zipp has received research grants from Teva, Merck

Serono, Novartis and Bayer as well as consultation funds from Teva,

Merck Serono, Novartis, Bayer Healthcare, Biogen Idec Germany,

ONO, Genzyme, Sanofi-Aventis and Octapharma. Her travel com-

pensation has been provided for by the aforementioned companies.

Ethical standard All patients gave their written informed consent

to examinations before participating in this study, which was ap-

proved by the local ethics committee and adhered to institutional

guidelines in accordance with the Declaration of Helsinki.

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