endocrinology, cardiology, respiratory and sleep medicine

Endocrinology, Cardiology, Respiratory and Sleep Medicine, Neurosciences These posters or presentations are available at the padlet https://padlet.com/ResearchFest/2021_EndoCardioRSMNeuro The numbers in the left column are the position of the work in the display Authors Title of abstract keywords CR01 Rajapaksha I, Gunarathne L, Herath C, Angus P, Angiotensin converting enzyme 2 gene

therapy improves glycaemic control in diabetic mice

ACE2 gene therapy, Diabetes, NAFLD

CR02 Gunarathne, L.S., Rajapaksha, I.G., Herath, C.B., Angus, P.W. Mas related G-protein coupled receptor type-D (MrgD) is a potential therapeutic target to inhibit splanchnic vasodilatation in cirrhotic portal hypertension

Portal hypertension, Cirrhosis, MasR, MrgD

CR03 Whenn C, Wilson D, Churchward TJ, Ruehland WR, Worsnop CJ, Tolson J

The impact of including oxygen desaturations occurring during awake epochs on the oxygen desaturation index.

Oximetry, sleep

CR04 Sheers N; Howard M.E; Hannan L; Retica S; Berlowitz D.J. Research in the time of COVID-19: Recruitment to a clinical trial comparing models of NIV implementation in people with MND

COVID-19, research trial recruitment

CR05 Suzana Miseski, Julie Tolson, Warren Ruehland, Christopher Worsnop, Pavlina Toman and Thomas Churchward

Automated Vs. Expert manual analysis of the Multiple sleep Latency Test

CR06 DL Wilson, C Whenn, M Barnes, SP Walker, ME Howard A trial of a position modification device for the prevention of supine sleep during pregnancy

pregnancy, sleep position, supine, SDB

CR07 ChurchwardT and Kao C, D’Rozario A, Wimaleswaran H, McMahon M, HowardM, Tolson J, Ruehland W

Quantitative EEG analysis of polysomnography in a case of Fatal Familial Insomnia.

CR08 Rishu Agarwal, Wendi Lin, Suzanne Svobodova, Chun Fong NGS based clonality testing for assessing clonality status, somatic hypermutation and minimal residual disease in lymphoid disorders.

CR09 Zimeng Ye, Sufang Lin, Xia Zhao, Yi Yao, Lin Li, Li Chen, Jing Duan, Zhide Cao, Zhanqi Hu, Samuel F. Berkovic, Ingrid E. Scheffer, Jianxiang Liao, Michael S. Hildebrand

Parental Mosaicism in "De Novo" Tuberous Sclerosis Complex

Tuberous Sclerosis Complex; Parental Mosaicism

ResearchFest 2021 Endocrinology, Cardiology, Respiratory and Sleep Medicine, Neurosciences Abstracts

https://padlet.com/ResearchFest/2021_EndoCardioRSMNeuro

CR10 Timothy E. Green, Mareike Schimmel, Susanna Schubert, Johannes R Lemke, Mark F. Bennett, Michael S. Hildebrand, Samuel F. Berkovic

Bi-allelic SMO variants in Hypothalamic Hamartoma: a recessive cause of Pallister-Hall syndrome

CR11 Michael Ginevra, Kevin D O'Connor, Linda Dalic Anakinra used to treat seizures 5-years after new-onset refractory status epilepticus

NORSE, Epilepsy, Anakinra, case report

CR12 Stanley Hughwa Hung, Mohamed Salah Khlif, Sharon Kramer, Emilio Werden, Laura J Bird, Bruce CV Campbell, Amy Brodtmann

Post-stroke physical activity and white matter hyperintensities: a CAVNAS exploratory analysis

physical activity, stroke, neuroimaging, neuroscience

CR13 Andrew K. Nunn,Morry Silberstein, Mary P. Galea A Human Sensory Pathway Connecting the Foot to Ipsilateral Face That Partially Bypasses the Spinal Cord

a new neural network

CR14 Desneves, KJ , Panisset, MG , Galea, MP , Kiss, N , Daly, RM , Ward, LC Comparison of segmental lean tissue mass in individuals with spinal cord injury measured by dual energy X-ray absorptiometry and predicted by bioimpedance spectroscopy

body composition, lean tissue mass, spinal cord injury

CR15 Dr Jesse Schnall, Georgina Oliver, Sabine Braat, Prof Richard Macdonell, Dr Katherine Gibney, Prof Richard Kanaan

A case series of Australian patients with debilitating symptom complexes attributed to ticks (DSCATT).

CR16 Restrepo C, Patel SK, Khlif MS, Bird LJ, Singleton R, Werden E, Ekinci EI, MacIsaac RJ, Burrell LM, Brodtmann A

This abstract is not included at the request of the author

Cardiovascular risk, cognition, atrophy, dementia

CR17 N Krishnadas, V Doré, R Mulligan, R Tyrrell, S Bozinovski, K Huang, F Lamb, S Burnham, VL Villemagne, CC Rowe


Tau, Longitudinal, Positron Emission Tomography (PET), Alzheimer's disease, ageing

CR18 N Krishnadas, V Doré, F Lamb, R Tyrrell, S Bozinovski, VL Villemagne, CC Rowe


Amyloid, tau, Alzheimer's disease, Positron Emission Tomography (PET)


CR19 Mohamed Nasra, Goran Mitreski, Hong Kuan Kok, Julian Maingard, Lee-Ann Slater, Jeremy H. Russell, Jonathan Hall, Winston Chong, Ashu Jhamb, Duncan Mark Brooks, Hamed Asadi


Blood Blister Aneurysm, Endovascular, Microsurgical, Stent, Flow Diversion, Clip, Bypass

CR20 Linda J Dalic, Aaron E.L Warren, Leonid Churilov, Wesley Thevathasan, Annie Roten, Kristian Bulluss, John S Archer


Epilepsy; deep brain stimulation; seizures; neurosurgery; neuromodulation

CR21 Patel SK, Restrepo C, Khlif MS, Werden E, Singleton R, Alsawaf S, Ramchand J, Srivastava PM, Zajac JD, MacIsaac RJ, Ekinci EI, Burrell LM, Brodtmann A


Left ventricular hypertrophy, diabetes, brain atrophy, dementia

CR22 Nie T, Venkatesh V, Golub S, Zajac JD, Grossmann M, Davey RA This abstract is not included at the request of the author

transgender, endocrinology, estradiol, bone, microCT

CR23 Mojtaba Lotfaliany, Aurora Poon, Kartik Kishore, Niloufar Torkamani, Vuthi Khanijou, Richard J. MacIsaac, Leonid Churilov, Elif I. Ekinci


CR24 Mojtaba Lotfaliany, Aurora Poon, Kartik Kishore, Niloufar Torkamani, Vuthi Khanijou, Richard J. MacIsaac, Leonid Churilov, Elif I. Ekinci





CR26 Chau Ng, Mina Botrous, Peter Mount, Darren Lee, Matthew Davies This abstract is not included at the request of the author

Peritoneal dialysis, kidney transplant, peritoneal dialysis catheter removal, deceased donor kidney transplantation


CR27 Sampaio Rodrigues T, Patel SK, Lancefield T, Jess A, Moini N, Ramchand J, Kwong J, Yates P, McDonald CF, Stewart S, Burrell LM


cardiovascular disease; clinical trial; seasonality

CR28 Restrepo C, Patel SK, Khlif MS, Bird LJ, Singleton R, Werden E, Ekinci EI, MacIsaac RJ, Burrell LM, Brodtmann A


Cardiovascular risk, cognition, atrophy, dementia





Rajapaksha I, 1, Gunarathne L,1, Herath C, 1,2, Angus P, 1,3

¶ Angiotensin converting enzyme 2 gene therapy improves glycaemic control in diabetic mice ¶ 1. Department of Medicine, The University of Melbourne, Austin Health Heidelberg, Vic., Australia; 2. South Western Sydney Clinical School, Faculty of Medicine, Ingham Institute for Applied Medical Research, University of New South Wales, Australia; 3. Department of Gastroenterology, Austin Health, Heidelberg, Vic., Australia. ¶ Aim Approximately 70% of type 2 diabetics develop non-alcoholic fatty liver disease (NAFLD) and NAFLD induced cirrhosis and liver cancer have become a major cause of morbidity and mortality in diabetic patients. Angiotensin-converting enzyme 2 (ACE2), the major enzyme of the protective arm of the renin angiotensin system (RAS), generates the anti-diabetic peptide angiotensin-(1-7) from the pro-diabetic peptide, angiotensin II. In the current study, we investigated whether ACE2 gene therapy using an adeno-associated viral (AAV) vector decorated with a capsid showing trophism towards the pancreatic cells improves glycaemic control in diabetic NAFLD mice. Methods Mice fed the HFHC diet for 40 weeks were rendered diabetic by streptozotocin injections after 15-weeks and were given a single intraperitoneal injection of recombinant AAV2/8 vector carrying mouse ACE2 gene (rAAV2/8-mACE2) after 30-weeks of the diet and sacrificed 10 weeks later. Fasting plasma insulin and glucose, islet numbers and islet insulin and ACE2 protein content were determined to evaluate the effect of ACE2 in the diabetic pancreas. β-cells (MIN6) and α-cells (α-TC clone 6) were also transduced with ACE2 vector. Results ACE2 therapy significantly increased islet numbers in diabetic mice, leading to increased insulin protein content in β-cells, resulting in increased plasma insulin levels with subsequent reduction in plasma glucose levels compared to controls vector injected diabetic mice. There was strong ACE2 protein expression, co-localised with insulin, in the islets of ACE2-treated diabetic mice. There was high ACE2 mRNA expression in ACE2 vector-transduced α- and β-cells compared to control vector-transduced cells. Conclusion We demonstrate that ACE2 therapy targeting pancreatic β-cells stimulates islet re-growth, leading to increased β-cells and insulin production with subsequent reduction in plasma glucose levels in diabetic NAFLD mice. We conclude that ACE2 gene therapy has the potential to improve insulin synthesis and/or secretion with subsequent improvement in glycaemic control in diabetic NAFLD patients.


Gunarathne LS1, Rajapaksha IG1, Herath CB1,2, Angus PW1,3 Mas related G-protein coupled receptor type-D (MrgD) is a potential therapeutic target to inhibit splanchnic vasodilatation in cirrhotic portal hypertension 1. Department of Medicine, The University of Melbourne, Austin Health, Heidelberg,

VIC, Australia. 2. South Western Sydney Clinical School, Faculty of Medicine, Ingham Institute for

Applied Medical Research, University of New South Wales, NSW, Australia. 3. Department of Gastroenterology & Hepatology, Austin Health, Heidelberg, VIC,

Australia. Aims Splanchnic vasodilatation plays a central role in the pathogenesis of cirrhotic portal hypertension (PHT). In cirrhosis, angiotensin-(1-7) mediates splanchnic vasodilatation via the Mas receptor (MasR). Recently discovered Mas related G-protein coupled receptor type-D (MrgD) is an alternate receptor for angiotensin-(1-7); however, its contribution to circulatory changes that occur in cirrhosis is unknown. In this study, we examined the expression of MrgD in experimental and human cirrhosis to investigate its possible role as a therapeutic target in PHT. Methods Liver and mesenteric vascular bed (MVB) samples were collected from Sprague-Dawley rats with cirrhotic PHT induced by bile duct ligation (BDL) or carbon-tetrachloride (CCl4) injections. Healthy and sham-operated rats served as controls. Liver and omental vessels were collected from human patients with cirrhosis due to primary sclerosis cholangitis (PSC) or alcohol, and samples collected from non-cirrhotic liver cancer resected patients served as controls. Liver and vessel gene expression of MrgD and MasR was analysed by RT-qPCR and protein expression by western blotting and immunohistochemistry. Results MasR and MrgD were markedly upregulated in the MVB of cirrhotic BDL and CCl4 rats compared to healthy controls. Similarly, MrgD and MasR expressions were upregulated in human cirrhotic omental vessels compared to control vessels. However, in cirrhotic rat livers, MasR was upregulated whilst MrgD expression was low and unchanged compared to controls. In human cirrhotic livers, MasR, but not MrgD expression was detected. Conclusion These findings suggest that MrgD may play an important role in mediating splanchnic vasodilation in cirrhotic PHT. Although MasR is upregulated, there was minimal hepatic expression of MrgD. This suggests that unlike MasR blockers, drugs that inhibit MrgD may be expected to reduce splanchnic vasodilation without adversely affecting hepatic resistance. We therefore conclude that MrgD is a promising target for the design and development of novel splanchnic vasculature-specific therapies to treat PHT in cirrhosis.


Whenn C1,2, Wilson D1,2,3, Churchward TJ1,2, Ruehland WR1,2, Worsnop CJ1,2,3, Tolson J1,2,3

The impact of including oxygen desaturations occurring during awake epochs on the oxygen desaturation index.

1. Department of Respiratory and Sleep Medicine, Heidelberg, Vic, Australia

2. Institute for Breathing and Sleep, Heidelberg, Vic, Australia

3. University of Melbourne, Parkville, Vic, Australia

Introduction

The oxygen desaturation index (ODI) is an important measure of sleep disordered breathing during

polysomnography (PSG) however there is no accepted standard for its calculation. The AASM Manual for

the Scoring of Sleep and Associated events (V2.6) does not specify whether oxygen desaturations

occurring during awake epochs should be included. More generally, epoch-based scoring is potentially

problematic for accurate ODI calculation. This study aims to compare the calculation of ODI including

and excluding oxygen desaturations occurring during awake epochs and to determine the impact of

sleep efficiency on any discrepancy.

Methods

Using twenty-one consecutive unattended PSG’s for investigation of OSA, two oxygen desaturation

indices were calculated from each PSG; one excluding (ODIsleep) and one including (ODIall) oxygen

desaturations marked in awake epochs.

Results

The median (IQR) ODIall was 19.3 (10.3, 27.0) and ODIsleep was 13.0 (6.6, 16.7). The median (IQR) difference

(ODIall - ODIsleep ) was 5.2/h (2.7, 10.4). This difference was greater with decreasing SE (r = -.63, p = .002).

Patients with SE ≤ 75% (n=10) had a median ODI difference of 11.5/h (4.0, 17.6), and those with SE > 75%

(n=11) had a difference of 2.8/h (2.0, 5.5) (p = .02).

Discussion

ODI was greater when including oxygen desaturations during awake epochs, with this discrepancy being

greatest when SE is ≤ 75%. We plan to confirm these findings in a larger sample. This investigation

informs clinical practice, highlights the difficulties of epoch scoring, and informs future standards for the

scoring of sleep and associated events.


Sheers N,1,2,3 Howard M.E.,1,2,3 Hannan L,3,4 Retica S,5 Berlowitz D.J.1,2,3,5

Research in the time of COVID-19: Recruitment to a clinical trial comparing

models of NIV implementation in people with MND

1. Victorian Respiratory Support Service, Department of Respiratory and Sleep

Medicine, Austin Health

2. The University of Melbourne

3. Institute for Breathing and Sleep

4. Department of Respiratory Medicine, The Northern Hospital

5. Department of Physiotherapy, Austin Health

Introduction

A pilot randomised controlled trial (RCT) examining the feasibility of a new model of

non-invasive ventilation (NIV) implementation was due to commence in early 2020.

Based on previous research, it was anticipated that 100% of people with motor

neurone disease (MND) would be eligible, 60% would consent to participate and 20

people would be randomised in five months. The aim of this report is to describe the

impact of the COVID-19 pandemic contingencies in Victoria on trial recruitment.

Methods

Report of project progress, participant screening and recruitment.

Results

First reports of COVID-19 coincided with study commencement and changed usual

healthcare delivery. Lockdowns meant telehealth substituted for face-to-face

assessment, respiratory function testing was limited and/or patients were reluctant to

seek medical treatment. This modified-assessment pathway impacted evaluation of

diagnosis, timing of need for NIV and procedural safety, with patients then referred

specifically for a single-day hospital NIV implementation to enable face-to-face

multidisciplinary assessment to aid decisions. Of 81 potential participants screened in

an 8-month period, 64% were ineligible for the RCT. Despite this shift in eligibility rate,

16 people with MND have been recruited as of May 2021.

Conclusion

The current climate has amplified the significance of this research trial; people with

MND have had reduced access to face-to-face services globally, and clinicians have

had to quickly adapt to a changing landscape of telemedicine and remote monitoring

of patients. This trial’s screening data suggests that COVID-19 hasn’t stopped people

with MND being implemented on NIV, but it has altered assessment pathways.


Authors: Suzana Miseski 1 2, Julie Tolson 1 2 3, Warren Ruehland 1 2, Christopher Worsnop 1 2 3, Pavlina

Toman 1 2, Thomas Churchward 1 2.

1. Austin Health, Heidelberg, Vic., Australia.

2. Institute for Breathing and Sleep (IBAS), Heidelberg, Vic., Australia.

3. University of Melbourne, Parkville, Vic., Australia.

Automated vs. Expert manual analysis of the Multiple Sleep Latency Test

Purpose. To compare Compumedics Profusion PSG™ automated sleep analysis of Multiple Sleep Latency Tests (MSLTs) with expert consensus manual analysis. 

Methods. Consecutive PSG with MSLTs were analysed using automated software (Compumedics Ltd (Abbottsford, Victoria, Australia) Profusion PSG™ V4.5 Build 531) (‘Auto’) and by two of nine experienced scientists. Discrepancies between scientists were discussed to establish expert consensus (‘Final’). 

Results. Fifty consecutive patients referred for investigation of Narcolepsy were included. Two were excluded due to poor signal quality (1) and early test termination (1). The remaining 48 (37 M, 10 F, 1) had a median (range) age of 37 (17-63) years, BMI 28.0 (19.9-66.1) kg/m2, and mean sleep latency (MSL) 14.0 (1.5-20.0) minutes.

Of five MSLTs with MSL <=8 min, Auto-MSL was also <=8 min. Of 43 MSLTs with MSL >=8 min, Auto-MSL was <=8 min in 12. MSL sensitivity was 100% and specificity 72%. 

For the one MSLT with >=2 SOREMs, Auto identified 1SOREM. 

Nap-wise, Auto-SOREM sensitivity was 17% and specificity 98%; one of six REM-positive naps was detected by auto-analysis and there were seven false positive and five false negative SOREM results. 

Conclusions. (1) Automated analysis poorly detected short MSL and SOREM occurrence in this MSLT dataset but was able to rule-out all true-negative results. (2) This comparison methodology and dataset facilitates robust prospective testing of other current and future algorithms.


Wilson DL1,2, Whenn C1,, Walker SP2,3, Barnes M1,4, Howard ME1,4

A trial of a position modification device for the prevention of supine sleep during pregnancy

1. Institute for Breathing and Sleep, Heidelberg, Vic., Australia; 2. Department of Obstetrics and Gynaecology, University of Melbourne, Parkville, Vic., Australia; 3. Mercy Perinatal, Mercy Hospital for Women, Heidelberg, Vic., Australia; 4. Department of Medicine, University of Melbourne, Parkville, Vic., Australia. Aim Self-reported supine position at sleep onset during late pregnancy is related to a 2.6x increase in stillbirth risk1, possibly due to the enlarged uterus compressing major blood vessels supplying the placenta. This study aimed to test the effectiveness of a pillow designed to decrease supine sleep in pregnant women. Methods Twelve women in the third trimester of pregnancy used their own pillows for a control week and the intervention pillow for a week, in randomised order. Sleep position for each night of both weeks was monitored with the Night Shift Sleep Positioner, with a sleep study (WatchPat300) on the last night of each week to measure the impact of the intervention on sleep-disordered breathing. Results During the control week, the women slept supine for a median of 19.9% (IQR = 11.6, 27.4) of total sleep time (TST), compared to a median of 20.4% (10.2, 31.0) TST using the intervention pillow (p = .64). Use of the intervention pillow did not impact sleep efficiency (control = 85.3% (80.7, 88.0) v. intervention = 85.2% (78.3, 89.0), p = .48). On the sleep study night, supine sleep was reduced in the intervention compared to control condition (12.9% vs. 17.7%, p = .04), but AHI did not differ (intervention = 2.6/hr (0.8, 6.7) vs. control = 1.5/hr (0.6, 3.6), p = .11). Conclusion We found that the adoption of a pillow designed to discourage supine sleep was not effective in late pregnancy. Considering the reasonably high amount of supine sleep in our participants, alternative devices should be investigated.

References

1. Cronin RS, Li M, Thompson JM, et al. An individual participant data meta-analysis of maternal going-to-sleep position, interactions with fetal vulnerability, and the risk of late stillbirth. EClinicalMedicine. 2019; 10: 49-57.


Churchward T 1 2 and Kao C 5, D’Rozario A 4 5, Wimaleswaran H 1 2, McMahon M 1 2, Howard M 1 2 3,

Tolson J 1 2 3, Ruehland W 1 2

1 Austin Health, Heidelberg, Vic, Australia

2 Institute for Breathing and Sleep, Heidelberg, Vic, Australia

3 University of Melbourne, Parkville, Vic, Australia

4 School of Psychology, University of Sydney, Camperdown, NSW, Australia

5 Centre for Sleep and Chronobiology, Woolcock Institute of Medical Research, Glebe, NSW,

Australia

Title.

Quantitative EEG analysis of polysomnography in a case of Fatal Familial Insomnia.

Purpose.

To report on quantitative electroencephalograph (EEG) activity during polysomnography (PSG) in a

rare case of confirmed Fatal Familial Insomnia (FFI).

Methods.

Sleep/wake characteristics of a 32-year-old male patient were quantitatively analysed using central

EEG recordings during two PSGs (FFI-1 and FFI-2) first, for investigation of insomnia and PLMS but

with no suspicion of FFI and second, 120 days later with suspected but unconfirmed FFI at the time;

89 days prior to death. PSG metrics; absolute EEG power in specified frequency bands; EEG slowing

ratio of slow-to-fast frequencies ((delta + theta)/ (alpha + sigma + beta)); and sleep spindle density

were calculated. Results were compared with gender and age-matched insomnia and healthy

controls (two of each).

Results.

FFI-1 and FFI-2 PSGs revealed total time in bed of 413.5 and 392 minutes, total sleep times of 208.5

and 7.5 minute, including NREM 153.0 and 2.5 minutes, and REM 55.5 and 5.0 minutes, respectively.

FFI-1 had approximately 1.5 times lower slow wave activity (SWA, 0.5-4.5Hz) during N3 than

insomnia and controls. FFI-1 had 2 times and 1.8 times higher slowing ratio during REM than

insomnia and controls, respectively. Spindle density (per minute of NREM sleep) for FFI-1 was 0.9,

compared to pair-averages of 1.2 for insomnia disorder and 4.7 for healthy controls.

Conclusions.

PSG in FFI revealed poor sleep efficiency that severely deteriorated with disease progression.

Quantitative analysis of EEG revealed lower spindle density, lower SWA in N3, and higher slowing

ratio in REM, when compared to insomnia patients and healthy sleepers.


Title: NGS based clonality testing for assessing clonality status, somatic

hypermutation and minimal residual disease in lymphoid disorders.

Aim: Molecular assays for assessing clonal rearrangement of the immunoglobulin receptor

(IgH) and T-cell receptor (TCR) genes, as well as determination of IgH somatic mutation

status, enables improved diagnostic accuracy and disease monitoring in lymphoid

malignancies. Next generation sequencing (NGS) based assays allows identification of the

full range of clonal populations, with underlying DNA sequences, and offers improved

sensitivity over conventional testing. Here, we evaluated the performance of an NGS based

assay for clonality and MRD (minimal residual disease) testing in patients with ALL (Acute

Lymphoblastic Leukaemia), CLL (Chronic Lymphocytic Leukaemia) and lymphomas.

Method: Patient samples were analysed using the LymphoTrack® Dx and MRD Assay to

detect IGH/TCR gene rearrangements. Target regions were sequenced on Illumina® MiSeq

and data was analysed using the LymphoTrack® Software. NGS results were correlated

with ASO-PCR, flow cytometry and clinical details.

Results: A diagnostic clone was identified in ~85% of B-ALL (22/26) samples. 82% (28/34)

concordance was obtained between TCRG NGS based assay and conventional assays for

T-cell disorders. MRD monitoring assay was able to detect 1 leukemic cell in 100,000 normal

cells (10-5 sensitivity) for B-cell malignancies. The addition of the spike-in LymphoQuant™

control enabled to report the MRD results as the percentage of total cells. There was ~80%

(43/55) concordance between MRD monitoring methods, NGS detected MRD at lower levels

than conventional assays & correlated well with the poor clinical outcomes. The IgHV

somatic hypermutation assay for CLL showed 100% (26/26) concordance with functionality,

genes identified, percentage homology, classification and subsets enumeration.

Conclusion: Our study demonstrates that NGS based testing can be successfully

implemented in diagnostic laboratories for establishing IgH and TCR based clonality. The

assay generates and quantifies clonal sequences for disease monitoring, is substantially

more sensitive than conventional PCR based assays, detects clonality results in specimens

that have failed conventional assays, and is highly concordant with clinical & histological

diagnosis.


Parental Mosaicism in “De Novo” Tuberous Sclerosis Complex

Zimeng Ye1,*, Sufang Lin2, *, Xia Zhao2, *, Yi Yao2, Lin Li2, Li Chen2, Jing Duan2, Zhide

Cao2, Zhanqi Hu2, Samuel F. Berkovic1,3, Ingrid E. Scheffer1,3,4,5*, Jianxiang Liao2,*, Michael

S. Hildebrand1,3,4,*

1Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Heidelberg, Victoria

3084, Australia; 2Epilepsy Centre, Department of Neurology, Shenzhen Children’s Hospital, Shenzhen,

Guangdong Province 518038, China; 3Austin Health, Heidelberg, Victoria 3084, Australia; 4 Murdoch

Children’s Research Institute, The Royal Children’s Hospital, Parkville, Victoria 3052; 5 Florey Institute

of Neuroscience and Mental Health, Parkville, Victoria 3052, Australia *These authors contributed

equally to this work

Rationale: Tuberous sclerosis complex (TSC) is a genetic disorder associated with

neurological, renal, dermatological and other anomalies. Over 85% of reported patients have

germline mutations in TSC1 or TSC2, with a higher yield of pathogenic variants in cohorts with

more severe, earlier onset disease. Some patients appear to have “de novo” variants on routine

testing of parental blood-derived DNA, yet one parent may have clinical features of TSC or

multiple affected children carrying the same germline mutation, indicating the likelihood of

low-level parental mosaicism. We aimed to identify parental mosaicism in 7 families with TSC

and features suggesting underlying parental mosaicism.

Methods: Seven families had known pathogenic germline mutations previously identified in

the probands on clinical genetic testing. All parents were negative for their child’s variant on

segregation analysis via clinical Sanger sequencing. Blood, saliva, buccal and urine DNA were

obtained from all parents. Droplet digital PCR (ddPCR) or deep targeted amplicon sequencing

(5,000x) were used to detect and quantitate the variants in parental tissues.

Results: We found parental mosaicism in blood-derived DNA in five of 7 families at low

frequency ranging from 0.1-8.8%, all well below the threshold of detection by Sanger

sequencing. In 3 parents with mosaic variants, we determined variant allele frequency (VAF)

in different tissues. One parent had mosaicism at a similar level across four different tissues

(7.26-9.11% VAF); while in the other two parents, mosaicism was variable (0.9-3.12% VAF

across three tissues and 0.39-2.2% VAF across four tissues, respectively). Of the two families

without mosaicism detected, one had two affected children carrying the same germline

mutation so one parent must have gonadal mosaicism that we could not detect in peripheral

tissues. In the second negative family, the mother has unilateral renal hamartoma without any


other clinical features of TSC; so, her hamartoma may not be due to TSC.

Conclusions: Our findings confirm that low-level parental mosaicism missed on routine

clinical testing can be detected with high levels of coverage. This finding has critical

implications for reproductive counseling.

Funding: This study was supported by a Sanming Project of Medicine in Shenzhen, China

(SZSM201812005) to J.L. and I.E.S., and National Health and Medical Research Council

Program Grant (1091593) to I.E.S. and S.F.B., a Project Grant (1129054) to S.F.B., a Project

Grant (1079058) to M.S.H., a Practitioner Fellowship (1006110) to I.E.S., and a R.D Wright

Career Development Fellowship (1063799) to M.S.H.

Characters (including spaces):

Title: 58; abstract body: 2,248; funding: 404; total: 2,652/3,200.


Bi-allelic SMO variants in Hypothalamic Hamartoma: a recessive cause of Pallister-

Hall syndrome

Timothy E. Green,1, Mareike Schimmel,2, Susanna Schubert,3, Johannes R Lemke,3,

Mark F. Bennett,1,4,5, Michael S. Hildebrand,1,6*, Samuel F. Berkovic,1*

1. Epilepsy Research Centre, Department of Medicine, The University of Melbourne,

Austin Health, Heidelberg, Victoria, 3084, Australia

2. Children’s Hospital, University Hospital Augsburg, Augsburg, Germany

3. Institute of Human Genetics, University of Leipzig Medical Centre, Leipzig, Germany

4. Population Health and Immunity Division, The Walter and Eliza Hall Institute of

Medical Research, Melbourne, Victoria, Australia

5. Department of Medical Biology, University of Melbourne, Melbourne, Victoria,

Australia

6. Neuroscience Research Group, Murdoch Children’s Research Institute, Royal

Children’s Hospital, Parkville, Victoria, Australia

* These authors contributed equally to this work

Abstract

Pallister-Hall syndrome, typically caused by germline or de novo variants within the GLI3

gene, has key features of hypothalamic hamartoma and polydactyly. Recently, a few similar

cases have been described with bi-allelic SMO variants. We describe two siblings born to non-

consanguineous unaffected parents presenting with hypothalamic hamartoma, post-axial

polydactyly, microcephaly amongst other developmental anomalies. Previous clinical

diagnostic exome analysis had excluded a pathogenic variant in GLI3. We performed exome

sequencing re-analysis and identified bi-allelic SMO variants including a missense and

synonymous variant in both affected siblings. We functionally characterised this synonymous

variant showing it induces exon 8 skipping within the SMO transcript. Our results confirm bi-

allelic SMO variants as an uncommon cause of Pallister-Hall syndrome and describe a novel

exon-skipping mechanism, expanding the molecular architecture of this new clinico-molecular

disorder.


Anakinra used to treat seizures 5-years after new-onset refractory status

epilepticus

Authors: Michael Ginevra1, Kevin O’Connor2,3,4, Linda Dalic 1,5

1Department of Neurology, Austin Health, Heidelberg, Victoria, Australia.

2Department of Immunology, Royal Perth Hospital, Perth, Western Australia, Australia

3Department of Neurology, Joondalup Health Campus, Perth, Western Australia, Australia

4Department of Postgraduate Medical Education, Royal Perth Hospital, Perth, Western Australia, Australia

5Department of Medicine (Austin Health) University of Melbourne, Heidelberg, Victoria, Australia.

Anakinra, an IL-1 antagonist, has been used in acute treatment of febrile infection-related epilepsy

syndrome (FIRES) and new-onset refractory status epilepticus (NORSE). However, its use in the chronic

phase of NORSE has not been well-described.

We report the use of anakinra, 5-years after NORSE onset. A previously healthy 24-year-old man

presented with altered mental state, headache and fever followed by a status epilepticus.

Investigations during a 2-month admission did not identify a cause for seizures. Empiric

immunosuppression with oral prednisolone, intravenous immunoglobulin and plasma exchange was

trialled for presumed autoimmune aetiology, without improvement. One year post onset, repeat MRI

showed new hippocampal sclerosis. Despite five anti-seizure medications and vagal nerve stimulator,

average (± 1SD) generalised tonic-clonic seizure (GTCS) frequency 5-years post NORSE was 6.7±1.2

seizures/month and focal impaired awareness seizures (FIAS) was 6.3±7.5 seizures/month.

At age 29, anakinra 200mg daily was commenced. After 2-months, GTCS reduced to 1.0±0

seizures/month. There was no change in FIAS (8±2.8 seizures/month) or the number of epileptiform

discharged on 24-hour ambulatory EEG. Reduction in anakinra dose to 100mg daily saw sustained

reduction in GTCS at 12-months (1.4±0.9 seizures/month). Anakinra was well-tolerated with minor

injection site reaction only on initial use.

The reduction in tonic clonic seizures with use of anakinra may suggest either persisting inflammation

in the pathophysiology of chronic epilepsy post NORSE or a direct anti-epileptic effect of IL-1

antagonism as seen in in-vitro models. This case demonstrates a potential benefit in the use of

anakinra in NORSE related epilepsy years after initial disease.


Hung SH,1,2 Khlif MS,1 Kramer S,1,2,3,4 Werden E,1,2,5 Bird L,1,2 Campbell CV,1,6 Brodtmann A1,2,5 Post-stroke physical activity and white matter hyperintensities: a CAVNAS exploratory analysis

1. The Florey Institute of Neuroscience and Mental Health, University of

Melbourne, Victoria, Australia 2. Neurology Department, Austin Health, Victoria, Australia. 3. Centre for Quality and Patient Safety Research, Alfred Health

Partnership, Victoria, Australia 4. School of Nursing and Midwifery, Faculty of Health, Deakin University,

Victoria, Australia 5. Melbourne Dementia Research Centre, The Florey Institute of

Neuroscience and Mental Health, Victoria, Australia 6. Department of Medicine and Neurology, Melbourne Brain Centre at the

Royal Melbourne Hospital, University of Melbourne, Victoria, Australia Aims: White matter hyperintensities (WMHs) are associated vascular risk factors and increased risk of cognitive decline(1). Increasing physical activity (PA) is recommended to stroke survivors to reduce vascular risk factors(2). However, the relationship between post-stroke PA and WMH progression remains unclear. We examined the association between PA and total WMH volumes 12-months after stroke. Methods: We included ischemic stroke survivors from the Cognition And Neocortical Volume After Stroke (CANVAS)(3) cohort with available brain MRI at 3-months and 12-months post-stroke, and objective PA data at 12-months post-stroke. Total WMH volumes (mL) were estimated with manually edited, automated segmentations using the Wisconsin White Matter Hyperintensities Segmentation toolbox(4). Daily minutes of moderate-to-vigorous intensity PA (MVPA) was estimated using the SenseWear® Armband. Participants with MVPA ≥30 minutes/day were classified as “Meeting PA Guidelines”. We used univariable and multivariable quantile regression to estimate the association between PA (MVPA, 25th, 50th, 75th percentiles; Meeting PA Guidelines, 50th percentile) and 12-month total WMH volume, adjusted for age and intracranial volume. Results: One hundred participants were included (mean age 68.4±11.2 years, 30% female). MVPA was not associated with total WMH volume at 12-months. In univariable analysis, meeting PA guidelines was associated with lower total WMH volumes by 3.4 (95%CI: 0.8 – 22.7) mL. However, this association was not observed after adjusting for age. Age was associated with total WMH volume, where each year of older age was associated with 0.15 (95%CI: 0.06 – 0.20) mL of greater total WMH volume. Conclusion: MVPA was not associated with WMH volume at 12-months post-stroke. Meeting PA guidelines may be associated with lower WMH volume. However, this association did not persist in multivariable analysis. Older age remained a robust predictor of greater WMH volumes. Future, appropriately


powered, studies should examine the complex association between age, PA, WMH, and other variables, such as cardiorespiratory fitness. References 1. Debette S, Schilling S, Duperron M-G, Larsson SC, Markus HS. Clinical

Significance of Magnetic Resonance Imaging Markers of Vascular Brain Injury: A Systematic Review and Meta-analysis. JAMA Neurol. 2019 Jan 1;76(1):81–94.

2. Billinger SA, Ross A, Bernhardt J, Eng JJ, Franklin BA, Mortag JC, et al. Physical Activity and Exercise Recommendations for Stroke Survivors. Stroke. 2014 Aug 1;45(8):2532–53.

3. Brodtmann A, Werden E, Pardoe H, Li Q, Jackson G, Donnan G, et al. Charting Cognitive and Volumetric Trajectories after Stroke: Protocol for the Cognition and Neocortical Volume after Stroke (CANVAS) Study. Int J Stroke. 2014 Aug 1;9(6):824–8.

4. Ithapu V, Singh V, Lindner C, Austin BP, Hinrichs C, Carlsson CM, et al. Extracting and summarizing white matter hyperintensities using supervised segmentation methods in Alzheimer’s disease risk and aging studies. Hum Brain Mapp. 2014 Aug;35(8):4219–35.


Background and Aims:

We recently described a human ascending sensory pathway connecting the foot to ipsilateral face that partially bypasses the spinal cord, which, we speculate, might utilize cutaneous C-fiber cross-talk. To confirm this mechanism, we sought to stimulate the pathway in reverse from face to foot, in both healthy human volunteers and patients with clinical and MRI confirmation of spinal cord transection.

Methods:

We applied facial thermal pulses designed to stimulate C-nociceptors in both healthy volunteers and spinal cord injured patients. This was performed both before and after topical capsaicin application to ipsilateral lower thigh (20 g X 0.075% cream as a 10 cm wide band circumferentially). Laser Doppler blood flow (Moor Instruments, Devon, UK) was measured via probes attached with adhesive washers to the dorsum of each foot.

Results:

Facial thermal stimulation resulted in reduced ipsilateral foot blood flow, but not after blockade with cutaneous lower thigh capsaicin. This response occurred in both healthy participants and spinal cord injured patients.

Conclusions:

Our preliminary results support the contention that this pathway involves a series of paracrine-like C-fiber communications between bifurcating cutaneous sensory nerves, with serial antidromic and orthodromic conduction, given that it operates in both caudo-cranial and cranio-caudal directions. In addition to possibly being amenable to training spinal cord-injured patients to re-establish locomotion, this pathway may have significant implications in understanding a number of ipsilateral neural phenomena including jogger's migraine, referred itch and the mechanism of acupuncture.

References:

Chahl LA. Antidromic vasodilatation and neurogenic inflammation. Pharmacol Ther. 1988;37(2):275-300. Silberstein M, Nunn AK, Drummond PD, et al. A Human Sensory Pathway Connecting the Foot to Ipsilateral Face That Partially Bypasses the Spinal Cord. Front Neurosci. 2019;13:519.


Desneves, KJ 1,2, Panisset, MG 3, Galea, MP 3, Kiss, N 2, Daly, RM 2, Ward, LC 4 ¶ Title of abstract Comparison of segmental lean tissue mass in individuals with spinal cord injury measured by dual energy X-ray absorptiometry and predicted by bioimpedance spectroscopy

¶ 1. Nutrition and Dietetics Department, Austin Health, Heidelberg, Vic., Australia; 2. Deakin University, Geelong, Australia, Institute for Physical Activity and Nutrition (IPAN), Deakin University; 3. Department of Medicine, Royal Melbourne Hospital, The University of Melbourne; 4. School of Chemistry and Molecular Biosciences, The University of Queensland ¶ Aim To compare two methods for predicting segmental (arms, legs, trunk) lean tissue mass (LTM: non-bone fat free mass) from bioimpedance spectroscopy (BIS) against LTM measured from dual energy X-ray absorptiometry (DXA) in individuals with acute spinal cord injury (SCI).¶ Methods Fourteen participants (two female), within 8 weeks of traumatic SCI had BIS measured following an overnight fast and within 24-h of DXA scanning. Total body fat free mass (FFM, body weight minus fat mass) and segmental LTM were predicted from BIS using manufacturer’s proprietary software and a previously established SCI-specific prediction1 method. Appendicular LTM (ALM) was calculated from the sum of the LTM of the arms and legs. Agreement and strength of relationships with DXA for predicted LTM measures using both approaches were assessed using Lin’s concordance coefficient and limits of analysis agreement (LOA). ¶ Results The BIS proprietary method performed better than the SCI-specific prediction method in predicting DXA LTM, demonstrating substantial concordance for total body FFM (rc = 0.80), ALM (rc = 0.78), arm (rc= 0.76) and leg LTM (rc = 0.65) and a smaller bias and LOA for ALM (+0.8 vs. -3.4 kg; LOA -4.9 – 6.4 vs. -11.9 – 5.1 kg), arm (+0.02 vs. -0.3 kg; LOA -1.1 – 1.1 kg vs. -2.2 – 1.6 kg) and leg (+0.4 vs. -1.4 kg; LOA -2.0 -2.8 vs. -5.6 – 2.8) LTM. ¶ Conclusion BIS can be used to accurately predict total body FFM, segmental LTM and ALM in individuals with acute SCI.

References Cirnigliaro CM, La Fountaine MF, Emmons R, Kirshblum SC, Asselin P, Spungen AM, et al. Prediction of limb lean tissue mass from bioimpedance spectroscopy in persons with chronic spinal cord injury. J Spinal Cord Med. 2013;36(5):443-53.


Dr Jesse Schnall1, Georgina Oliver2, Sabine Braat3,4, Prof Richard Macdonell1, Dr Katherine Gibney5, 6*, Prof Richard Kanaan2*

*Joint last author A case series of Australian patients with debilitating symptom complexes attributed to ticks (DSCATT). 1. Austin Health, Heidelberg, 3084, Australia 2. Department of Psychiatry, University of Melbourne, Austin Health, Heidelberg,

VIC 3084 3. Centre for Epidemiology and Biostatistics, School of Population and Global

Health, The University of Melbourne, Melbourne Australia 4. MISCH (Methods and Implementation Support for Clinical Health research

platform), Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne Australia

5. Department of Infectious Diseases, Austin Health, Heidelberg, VIC 3084 6. The Peter Doherty Institute for Infection and Immunity, Department of Infectious

Diseases, Melbourne Medical School, University of Melbourne Aim To characterise the clinical history, cause of illness and treatment response of Australian patients with Debilitating Symptom Complexes Attributed to Ticks (DSCATT). Methods Single-centre case series of patients referred to Austin Health between 2014 and 2020 for work-up and treatment of suspected DSCATT. Patients were included if they had debilitating symptoms suggested by either themselves or the referring clinician as being attributed to ticks. Data were analysed using Microsoft Excel (Version 16.46, 2021 Microsoft). Results Twenty-nine cases were included for analysis. The most common prior medical and psychiatric diagnoses were Lyme disease (83%), Anxiety (48%), Depression (41%), Epstein-Barr virus (38%), chronic fatigue syndrome (28%) and fibromyalgia (24%). Common presenting symptoms included fatigue (83%), headache (72%) and arthralgia (69%). NATA-accredited serology was not diagnostic of Lyme disease, or other tick-borne diseases, in any patient. Of cases with available data, 53% reported benefiting from prior antimicrobial use. The most common diagnoses made by our health service were chronic fatigue syndrome (31%), migraines (28%) and fibromyalgia (21%). Only one patient had symptoms that were not accounted for by other diagnoses. Conclusion We present the first clinical case series of DSCATT in Australian patients. We found high rates of other medically unexplained syndromes, and no evidence of acute Lyme disease, or any common organic disease process. DSCATT remains medically unexplained, and may be due to an unidentified cause, or alternatively might be considered comparable to other conditions such as chronic fatigue syndrome.


endocrinology, cardiology, respiratory and sleep medicine

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