Objective: We performed an RNA-Seq analysis of tears from 16 Parkinson's Disease (PD) patients and 16 healthy, age-matched healthy controls (HC) to identify genes and pathways that may serve as biomarkers of PD. Background: We previously demonstrated that PD tears have significantly higher levels of oligomeric a-synuclein than HC tears. Analyses of hundreds of subjects demonstrated this biomarker predicted PD diagnosis, irrespective of disease duration (AUROC=0.76). To improve this model, we performed RNA-Seq on PD and HC tears. Pilot studies of brain and tears revealed ~74% of genes expressed in aged cortex were expressed in tears. Design/Methods: Schirmer's Tear Strips were frozen at −80°C. RNA was extracted and evaluated for quantity and integrity (RIN). RNA-Seq libraries were prepared with the NEBNext Ultra II RNA Library Prep Kit and sequenced on an Illumina NovaSeq sequencer. FASTQ files were aligned with Tophat and transcripts were counted and compared with Cufflinks. Pathway analysis was performed using the Qiagen Ingenuity Pathway Analysis (IPA) software and unsupervised, hierarchical clustering of significantly affected pathways was tested with RStudio. Results: RNA-Seq analysis showed more genes were downregulated in PD tears (N=898) vs. upregulated (N=238). IPA analysis of downregulated genes revealed DNA repair pathways were significantly affected, and reflected the downregulation of 60 genes related to DNA excision repair, recombination, and damage in PD tears. These 60 genes included HNRNPC, TARDBP, USP47, EZH2, FANCC. Unsupervised hierarchical clustering of these 60 genes' transcript levels (FPKMs) separated PD and HC with 83.9% accuracy (sensitivity 93.3% and specificity 75%). Conclusions: RNA-Seq may provide a useful strategy for PD diagnosis using tears, a non-invasive biofluid. Preliminary data suggests increased diagnostic accuracy compared to our tear investigations of oligomeric a-synuclein levels alone. Downregulation of DNA repair genes/pathways suggests that alterations observed in PD brains and dopaminergic neurons are also observed in tears Disclosure: Dr. Lew has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Supernus. Dr. Lew has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for kyowa. Dr. Lew has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for neurocrine. Dr. Lew has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Acorda. Dr. Lew has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Acadia. Dr. Lew has received personal compensation in the range of $500-$4,999 for serving as a Consultant for RegenXBio. Dr. Lew has received personal compensation in the range of $10,000-$49,999 for serving on a Speakers Bureau for Neurocrine. Dr. Lew has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for Kyowa. Dr. Lew has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for acorda. The institution of Dr. Lew has received research support from MJFF. Dr. Lew has received research support from NIH. Miss Omidsalar has nothing to disclose. Miss Singh Kakan has nothing to disclose. Mr. Gerke has nothing to disclose. Ms. Tanveer has nothing to disclose. Dr. Feigenbaum has nothing to disclose. Dr. Tamadonfar has nothing to disclose. Sarah Hamm-Alvarez has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Oyster Point. The institution of Sarah Hamm-Alvarez has received research support from Oyster Point. Dr. Hjelm has nothing to disclose.

Monday, April 27April 14, 2020Free AccessBiomarkers for Parkinson’s Disease with Reflex Tears Correlate with Disease Duration (4417)Mark Lew, Srikanth Janga, Danielle Feigenbaum, Dan Freire, Maria Edman, Wendy Mack, Curtis Okamoto, and Sarah Hamm-AlvarezAuthors Info & AffiliationsApril 14, 2020 issue94 (15_supplement)https://doi.org/10.1212/WNL.94.15_supplement.4417 Letters to the Editor

BackgroundThere is significant evidence for cognitive decline following deep brain stimulation (DBS). Current stimulation paradigms utilize gamma frequency stimulation for optimal motor benefits; however, little has been done to optimize stimulation parameters for cognition. Recent evidence implicates subthalamic nucleus (STN) theta oscillations in executive function, and theta oscillations are well-known to relate to episodic memory, suggesting that theta frequency stimulation could potentially improve cognition in Parkinson's disease (PD).ObjectiveTo evaluate the acute effects of theta frequency bilateral STN stimulation on executive function in PD versus gamma frequency and off, as well as investigate the differential effects on episodic versus nonepisodic verbal fluency.MethodsTwelve patients (all males, mean age 60.8) with bilateral STN DBS for PD underwent a double-blinded, randomized cognitive testing during stimulation at (1) 130–135 Hz (gamma), (2) 10 Hz (theta) and (3) off. Executive functions and processing speed were evaluated using verbal fluency tasks (letter, episodic category, nonepisodic category, and category switching), color-word interference task, and random number generation task. Performance at each stimulation frequency was compared within subjects.ResultsTheta frequency significantly improved episodic category fluency compared to gamma, but not compared to off. There were no significant differences between stimulation frequencies in other tests.ConclusionIn this pilot trial, our results corroborate the role of theta oscillations in episodic retrieval, although it is unclear whether this reflects direct modulation of the medial temporal lobe and whether similar effects can be found with more canonical memory paradigms. Further work is necessary to corroborate our findings and investigate the possibility of interleaving theta and gamma frequency stimulation for concomitant motor and cognitive effects.

Tears are a known source of biomarkers for both ocular and systemic diseases with particular advantages; specifically, the noninvasiveness of sample collection and a unique and increasingly better-defined protein composition. Here, we discuss our rationale for use of tears for discovery of biomarkers for Parkinson's disease (PD). These reasons include literature supporting changes in tear flow and composition in PD, and the interconnections between the ocular surface system and neurons affected in PD. We highlight recent data on the identification of tear biomarkers including oligomeric α-synuclein, associated with neuronal degeneration in PD, in tears of PD patients and discuss possible sources for its release into tears. Challenges and next steps for advancing such biomarkers to clinical usage are highlighted.

Aim: Secretion of proteins into basal tears of Parkinson's disease (PD) patients may be altered by changes in nerve function. Materials & methods: Oligomeric α-SynOligo and total α-SynTotal, CCL-2, DJ-1, LF and MMP-9 were measured in basal tears from 93 PD patients and 82 age- and sex-equivalent healthy controls. Results: α-SynTotal was decreased (p = 0.0043), whereas α-SynOligo (p < 0.0001) and the ratio of α-SynOligo/α-SynTotal (p < 0.0001) were increased in basal tears from PD patients compared with healthy controls. Area under receiver-operating curves of α-SynOligo and α-SynOligo/α-SynTotal contents were 0.70 (95% confidence limits: 0.621-0.774) and 0.72 (95% confidence limits: 0.642-0.792). Conclusion: PD patient basal tears may contain biomarkers that can be assayed noninvasively and inexpensively.

Objective: To evaluate whether the protein composition of reflex tears differs in individuals with Parkinson’s disease (PD) versus Healthy Controls (HC) Background: Lacrimal glands are highly innervated by cholinergic and other neurons, and tear fluid secreted by lacrimal glands is greatly stimulated by parasympathetic and sympathetic neural pathways. The production, packaging and secretion of specific proteins into tears may change in response to alterations in nerve function to lacrimal glands and cornea, which may be tested by collection of reflex tears. Reflex tears are stimulated tears collected with an unanesthetized Schirmer’s test. We have previously reported results with basal tears/anesthetized Schirmer’s test. Design/Methods: Reflex tears were collected from 85 PD patients and 80 age-and sex-matched HC using an unanesthetized Schirmer’s test. Samples were pooled from both eyes for analysis of alpha-synuclein, CC chemokine ligand 2 (CCL-2) and total protein. Values were measured by ELISA or multiplex ELISA. Results: Oligomeric alpha-synuclein was significantly increased by 4.7-fold in PD tears (4.21 ± 0.50 ng/mg tear protein) relative to HC (0.90 ± 0.13 ng/mg tear protein) (p Conclusions: Oligomeric synuclein levels enable discrimination between reflex tears of PD patients and HC. CCL-2 may represent an additional biomarker. The origin of sex differences in biomarker values requires further study. Disclosure: Dr. Lew has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Teva, US World Meds, UCB, Lundbeck, AbbVie, Adamas Pharmaceuticals, Cynapsus, Revance, Acadia Pharmaceuticals, Neurocrine Biosciences, and Acorda Therapeutics. Dr. Lew has received research support from Parkinson’s Study Group, Michael J. Fox Foundation, Biotie, Neuroderm, Enterin Inc., Pharm2B Fellowship Grants, Allergan, and Medtronic. Dr. Feigenbaum has received research support from Intec, Revance, Acorda. Dr. Freire has nothing to disclose. Dr. Janga has nothing to disclose. Dr. Mack has nothing to disclose. Dr. Edman has nothing to disclose. Dr. Okamoto has nothing to disclose. Dr. Hamm-Alvarez has nothing to disclose.

Aim: Due to active engagement of sensory and afferent nerve fibers in reflex tearing which could be affected in Parkinson's disease (PD), we tested reflex tears as a source of potential PD biomarkers. Patients & methods: Reflex tears collected from 84 PD and 84 age- and sex-equivalent healthy controls (HC) were used to measure levels of oligomeric α-Syn (α-SynOligo), total α-Syn (α-SynTotal), CCL2, DJ-1, lactoferrin and MMP9. Results: α-synOligo (p < 0.0001), CCL2 (p = 0.003) and lactoferrin (p = 0.002) were significantly elevated in PD patient tears relative to HC tears. Tear flow was significantly lower in PD relative to HC (p = 0.001). Conclusion: Reflex tears are a potential source for detection of characteristic changes in PD patients.

Hereditary diffuse leukoencephalopathy with axonal spheroids (HDLS) is a neurodegenerative disease presenting in midlife and associated with rapidly progressive cognitive, behavioral and motor symptoms. HDLS results from mutations in the CSF1R gene and is inherited in an autosomal dominant pattern. We describe the clinical and neuroimaging features of two cases of HDLS evaluated at our medical center.and compare them with previously reported cases. Both patients had clinical genetic testing done revealing mutations in CSF1R. Patient 1 is a 46 year old woman who initially presented with gait changes and dysarthria, with rapid progression of bulbar and cognitive symptoms over 18 months, and was found to have a mutation in exon 19, c.2519C>G (p.Ser840Cys). Patient 2 is a 56 year old man presenting with 3 years of depression and memory problems without significant motor symptoms in the context of a family history of early onset dementia syndrome in his mother and prior diagnosis of HDLS in his maternal aunt; he was also found to have a mutation in exon 19, c.2480T>A (p.Ile827Asn). Both patients demonstrated extensive white matter hyperintensities and thinning of the corpus callosum on their MRIs with Patient 1 having cavitary lesions. Both mutations are located in the tyrosine kinase domain of the protein at or near the location of previously described mutations. Both mutations are predicted to be probably damaging by Polyphen with a score of 1.0. To our knowledge, these are the first reported cases of HDLS associated with these mutations. As has been described in the literature, the female patient had a younger age of onset than the male. Clinicians should be aware of the diversity of clinical presentations of HDLS and consider genetic testing for atypical dementia syndromes associated with significant white matter changes.

April 22, 2018April 10, 2018Free AccessTear Proteins as Possible Biomarkers for Parkinson’s Disease (S3.006)Danielle Feigenbaum, Mark Lew, Srikanth Janga, Mihir Kunjeshkumar Shah, Wendy Mack, Curtis Okamoto, and Sarah Hamm-AlvarezAuthors Info & AffiliationsApril 10, 2018 issue90 (15_supplement)https://doi.org/10.1212/WNL.90.15_supplement.S3.006 Letters to the Editor