The DM1-Neuro Study: Myotonic dystrophy research update Mark Hamilton, Clinical Research Fellow

Key research questions Which methods represent meaningful outcome measures for CNS-symptoms of myotonic dystrophy How do structural brain changes relate to the severity of symptoms, in particular those of excessive daytime sleepiness?

The DM1-Neuro study Cohort 40 individuals with aDM1, plus 6 with MRI contraindications 20 age-matched controls Recruitment Comorbidities Genotyping by SP-PCR Clinical assessment Neuropsychological assessment Self-reported outcome measures MRI brain T1, T2 weighted imaging Diffusion tensor imaging Resting state functional MRI Sleep Studies Domiciliary polysomnography Modified maintenance of wakefulness tests

The DM1-Neuro study Cohort 40 individuals with aDM1, plus 6 with MRI contraindications 20 age-matched controls Recruitment Comorbidities Genotyping by SP-PCR Clinical assessment Neuropsychological assessment Self-reported outcome measures MRI brain T1, T2 weighted imaging Diffusion tensor imaging Resting state functional MRI Sleep Studies Domiciliary polysomnography Modified maintenance of wakefulness tests

Selection of neuropsychological assessment methods Consensus recommendations of OMMYD1 Colour-word Stroop test FAS word association Trailmaking Tests A & B  Trailmaking tests from D-KEFS Block design subtest from WAIS-R  WASI II Cognitive screen without motor tasks The Edinburgh Cognitive and Behavioral ALS Screen Explained that we used all of the tests recommended by the ‘Outcome measures in Myotonic Dystrophy’ consensus meeting, plus the ECAS, which we selected based on non-interference by motor impairment Self- and informant-reported outcome measures Myotonic Dystrophy Health Index DM1-ActivC© Fatigue and Daytime Sleepiness Score Self and carer Dex questionnaire Beck Depression Inventory II McGill pain scale SF-36 pain items

Summary scores for main neuropsychology assessments   Mean score of DM1-affected participants (SD) Mean score of control participants Cohen’s D effect size Stroop colour-word task 41.74 (10.40) 53.80 (7.98) 1.301 Trailmaking test (Number sequencing) 7.80 (3.74) 12 (1.59) 1.462 Trailmaking Test (number-letter sequencing) 8.41 (4.20) 11.70 (2.00) 1.000 FAS word association 36.59 (11.15) 47.10 (11.11) 0.944 Block design subtest 37.57 (9.79) 52.15 (8.49) 1.591 ECAS Total score 107.87 (11.69) 116.00 (9.50) 0.763 ECAS Visospatial 11.02 (1.45) 11.85 (0.37) 0.783 ECAS verbal fluency 17.35 (3.73) 18.70 (3.91) 0.354 ECAS Executive 35.87 (6.12) 39.35 (5.80) 0.583 ECAS Memory 17.04 (3.77) 18.90 (2.83) 0.559 ECAS language 26.59 (1.94) 25.90 (5.99) 0.155 0.6 On the face of it, a large difference is seen between the performance of DM1 patients and controls in all of the recommended tests. Scores on ECAS are still significant, but generally somewhat more modest. 0.3

Correction for motor impairment in D-KEFS trailmaking tests Component test Cohen’s D effect size (affected vs. control) Trail 2 (number sequencing) 1.462 Trail 4 (number-letter switching) 1.000 Trail 5 (motor) 1.427 Motor contrast score (Trail 4 scaled score – Trail 5) 0.087 Dm1-affected participants performed particularly poorly in Trailmaking - 11/46 (24%) more than 2 SDs below predicted on the number-letter switching task. However, also poor at trail 2 (predominantly a test of attention), and trail 5 (motor component isolated). When corrected for motor slowness, the difference vs controls is lost. Number-letter switching Motor 2 B A Start Start 1 3 C

Corrected scores for Stroop test Component test Cohen’s D effect size (affected vs. control) Word test 0.992 Colour test 1.377 Colour-word test 1.301 Stroop Interference 0.553 ECAS executive score 0.583 Similarly, correction of the Stroop colour-word score for performance in the first two tasks shows a more modest impairment, comparable to the ECAS executive score. Word test Colour test Colour-word test GREEN BLUE RED RED GREEN RED BLUE GREEN BLUE GREEN RED GREEN RED BLUE RED XXXX XXXX XXXX GREEN BLUE RED RED GREEN RED BLUE GREEN BLUE GREEN RED GREEN RED BLUE RED

Self-reported muscle impairment correlates with performance in neuropsychology assessments with a manual task Trail 5 (motor) scaled score Block design test (T-score) We cannot definitively say why DM1 patients are slow even at Trail 5 and the word test of Stroop. Attention and motivation may be factors. But we would suspect muscle impairment may play a role - further evidenced by the fact that performance in all of the trails correlate with self-reported muscle strength in DM1Active, as does score for block design test. We must therefore be cautious in recommending these tests as measures of CNS response to a drug therapy. p < 0.001; Adj R2 = 0.314 p = 0.001; Adj R2 = 0.191 ECAS subscores did not correlate with any scales of self-reported measures of muscle function

Low mood, pain and fatigue Significant correlations between depression scores and: Sleepiness and fatigue (R2 0.42) Pain (R2 0.25) Low mood also strongly predicts: Self-reported cognitive impairment (R2 0.61) Impaired social performance (R2 0.41) ‘Frontal’ personality traits (R2 0.48) Low mood 2% 33% 11% 0% 18% In self-reported measures we saw fatigue as a frequent issue, often accompanied by pain and low mood. Low mood was generally predictive of higher self-reported central symptoms. 17% 4% 15% Fatigue Pain

Automated segmentation of white matter hyperintensities MRI analysis: Automated segmentation of white matter hyperintensities It’s therefore useful to ask “do self-reported central symptoms correlate with any objective measures of disease?”. Neuropsychology ‘puzzles’ represent one objective measure, and imaging another. MRI analysis is in early stages (DTI, fMRI, regional volumes to come), but we do have white matter lesion volumes as illustrated

Self-reported cognitive impairment does not reflect severity of brain involvement Self-reported cognitive impairment did not correlate with any objective measures of CNS disease Trend towards higher depression scores and greater self-reported impairment in those with less white matter change Self-reported central symptoms did not correlate significantly with performance in any of the tests, nor with severity of imaging changes. In fact, there was a trend towards an inverse correlation, with patients with less severe brain changes more likely to be low in mood and report higher cognitive impairment. Unclear why those with worse brain changes don’t - ? Acceptance over time, ?? Impaired insight p = 0.129 p = 0.171

Informant-reported Dex score correlates significantly with severity of white matter disease Only significant correlation with brain changes is the carer-reported outcome. ?? Role for development of more carer-reported outcomes for future clinical trials. P = 0.001; R2 = 0.264 © Pearson Publishing 2006

Correlations with CTG repeat length logPAL is associated with self-reported age at onset (p = 0.09; R2 0.05) Modal allele length predicts scores in: - DM1ActivC (R2 0.12) - Trail 5 motor (R2 0.07) - Block design (R2 0.18) - Stroop interference (R2 0.16, in multivariate analysis with age) Our patients have been very accurately genotyped by small pool PCR. This technique has recently shown very good correlations with muscle measures in other populations. Sureprising therefore that correlations with our brain measures to date have been comparatively poor. Reasons might include: Self-reported measures are introduce subjectivity Neuropsychological measures are subject to wide variation within normal range, with modest additional effect of DM1 Additional environmental/genetic factors may be important for development of WMHs Based on previous literature, we would hope for better correlations with DTI measures.

Participants with variant trinucleotide repeats report fewer symptoms There is evidence that patients with variant repeats (CCG sequence within their CTG expansion) may have less severe symptoms than those with similar gene expansions made of pure CTG repeats. We found two patients with variant repeats, both of whom reported few symptoms as illustrated. AAT CTG CCG

Summary of first 15 domiciliary polysomnography studies Measure Mean (SD) Apnoea-hypopnoea index 25 (27) Central apnoea / hour 4 (8) Obstructive apnoea/ hour 0.1 (0.3) Central hypopnoea / hour 1.7 (4.0) Obstructive hypopnoea / hour 20 (15) Sleep efficiency (%) 76 (14.5) Periodic Limb Movement Index 11 (26) Mean sleep latency in mMWT 24 (10.0) We are in early stages of sleep study analysis, but clearly detecting lots of pathology as illustrated Sleep disordered breathing

Structure-phenotype correlations with MRI imaging In particular, we have found several patients with central apnoeas. Will be very interesting to correlate this with structural changes in specific brain regions on MRI.

Conclusions Recommended “executive” tests show significant interference from motor impairment Low mood is associated with greater severity of self-reported symptoms, particularly in those with mild CNS disease Correlations of brain phenotype with CTG repeat size are so far relatively poor compared with muscle Future directions will explore structural correlations with neuropsychology performance and sleep disorder

And thank you to the study participants and their families Acknowledgements Supervisors Darren G Monckton Maria E Farrugia University of Glasgow Sarah Cumming Gayle Overend Josephine McGhie Clarissa Hocking Dept of Neuroradiology John McLean Ravi Jampana The Scottish Myotonic Dystrophy Consortium Dept of Health and Wellbeing Jonathan J Evans University of Newcastle Antonio Atalaia Hanns Lochmuller Nikoletta Nikolenko University of Iowa Peg Nopoulos Vincent Magnotta Eric Axelson Dept of Clinical Genetics Bob Ballantyne Cheryl Longman Marina Di Marco Dept of Respiratory Medicine Eric Livingston Scott Davidson Alison Clarke And thank you to the study participants and their families

Contact: markhamilton1@nhs.net