Opioid use disorder (OUD) is a chronic disease of the brain, and it currently continues at crisis proportions in the United States. Opioid physical withdrawal is a major driver of compulsive drug-taking behavior, triggering short-term relapse of opioid addiction. Early pharmacological evidence shows that midbrain periaqueductal gray (PAG) plays an important role in morphine withdrawal (MW). However, we still know few details about the underlying molecular mechanisms. Improving our understanding of such mechanisms will enable increasingly safe and effective treatments for patients with OUD. Here, MW was induced by the naloxone precipitation after chronic intraperitoneal administration of morphine for a period of 5 d in Sprague Dawley male rats. MW increased phosphorylation of cAMP response element binding protein (pCREB, a primary marker of CREB functional activation), NMDA glutamate receptor 2B subunit (NR2B), and mitochondrial calcium uniporter (MCU) within the ventrolateral PAG (vlPAG). Inhibition of pCREB, NR2B, or MCU within this brain region reduced the severity of MW. Chromatin immunoprecipitation (ChIP) assay and luciferase report assay demonstrated that pCREB mediated the transcription of the Grin2b (glutamate ionotropic receptor NMDA type subunit 2B, encoding NR2B) and Ccdc109a (encoding MCU) genes. These findings describe the role of pCREB in Grin2b and Ccdc109a gene transcription levels in the vlPAG during MW. The study may provide a novel therapeutic approach for OUD.

Chronic pain remains a global health challenge, often resistant to available treatments with socioeconomic and psychological burdens. All chronic pain is believed due to neuronal signaling imbalances, resulting in increased excitability. Gene therapy represents a promising molecular therapy targeting molecular pain processing pathways, by offering precise, localized, long-lasting neuromodulation while minimizing systemic exposure and side effects. In model systems, replication-defective, disease-free, herpes simplex virus (rdHSV) gene therapy expressing an analgesic carbonic anhydrase-8 (CA8∗) peptide variant corrects somatosensory hyperexcitability by activating Kv7 voltage-gated potassium channels, produces profound, long-lasting analgesia and treats chronic pain from knee osteoarthritis (OA). In these studies, we provide the first non-glucagon-like peptide (GLP) biosafety, efficacy, biodistribution, shedding, and histopathology examination of this rdHSV-CA8∗. Naive mice were examined for clinical safety, biodistribution across all major tissues, knee histopathology, and analgesic efficacy via the intra-articular knee route of administration. We observed no signs of persistent toxicity, viral genomes remained where they were injected, and there was no evidence of shedding. Profound analgesia persisted for 6 months without functional impairments. These initial biosafety and efficacy data support further development of rdHSV-CA8∗ for treating chronic knee pain due to moderate to severe OA.

Chronic pain is common in our population, and most of these patients are inadequately treated, making the development of safer analgesics a high priority. Knee osteoarthritis (OA) is a primary cause of chronic pain and disability worldwide, and lower extremity OA is a major contributor to loss of quality-adjusted life-years. In this study we tested the hypothesis that a novel JDNI8 replication-defective herpes simplex-1 viral vector (rdHSV) incorporating a modified carbonic anhydrase-8 transgene (CA8*) produces analgesia and treats monoiodoacetate-induced (MIA) chronic knee pain due to OA. We observed transduction of lumbar DRG sensory neurons with these viral constructs (vHCA8*) (~40% of advillin-positive cells and ~ 50% of TrkA-positive cells colocalized with V5-positive cells) using the intra-articular (IA) knee joint (KJ) route of administration. vHCA8* inhibited chronic mechanical OA knee pain induced by MIA was dose- and time-dependent. Mechanical thresholds returned to Baseline by D17 after IA KJ vHCA8* treatment, and exceeded Baseline (analgesia) through D65, whereas negative controls failed to reach Baseline responses. Weight-bearing and automated voluntary wheel running were improved by vHCA8*, but not negative controls. Kv7 voltage-gated potassium channel-specific inhibitor XE-991 reversed vHCA8*-induced analgesia. Using IHC, IA KJ of vHCA8* activated DRG Kv7 channels via dephosphorylation, but negative controls failed to impact Kv7 channels. XE-991 stimulated Kv7.2–7.5 and Kv7.3 phosphorylation using western blotting of differentiated SH-SY5Y cells, which was inhibited by vHCA8* but not by negative controls. The observed prolonged dose-dependent therapeutic effects of IA KJ administration of vHCA8* on MIA-induced chronic KJ pain due to OA is consistent with the specific activation of Kv7 channels in small DRG sensory neurons. Together, these data demonstrate for the first-time local IA KJ administration of vHCA8* produces opioid-independent analgesia in this MIA-induced OA chronic pain model, supporting further therapeutic development.

BACKGROUND:Clinical data demonstrate that chronic use of opioid analgesics increases neuropathic pain in people living with human immunodeficiency virus (HIV). Therefore, it is important to elucidate the molecular mechanisms of HIV-related chronic pain. In this study, we investigated the role of the transcription factor cMyc, epigenetic writer enhancer of zeste homology 2 (EZH2), and sirtuin 3 (Sirt3) pathway in HIV glycoprotein gp120 with morphine (gp120M)-induced neuropathic pain in rats. METHODS:Neuropathic pain was induced by intrathecal administration of recombinant gp120 with morphine. Mechanical withdrawal threshold was measured using von Frey filaments, and thermal latency using the hotplate test. Spinal expression of cMyc, EZH2, and Sirt3 were measured using Western blots. Antinociceptive effects of intrathecal administration of antisense oligodeoxynucleotide against cMyc, a selective inhibitor of EZH2, or recombinant Sirt3 were tested. RESULTS:In the spinal dorsal horn, gp120M upregulated expression of cMyc (ratio of gp120M versus control, 1.68 ± 0.08 vs 1.00 ± 0.14, P = .0132) and EZH2 (ratio of gp120M versus control, 1.76 ± 0.05 vs 1.00 ± 0.16, P = .006), and downregulated Sirt3 (ratio of control versus gp120M, 1.00 ± 0.13 vs 0.43 ± 0.10, P = .0069) compared to control. Treatment with intrathecal antisense oligodeoxynucleotide against cMyc, GSK126 (EZH2 selective inhibitor), or recombinant Sirt3 reduced mechanical allodynia and thermal hyperalgesia in this gp120M pain model. Knockdown of cMyc reduced spinal EZH2 expression in gp120M treated rats. Chromatin immunoprecipitation (ChIP) assay showed that enrichment of cMyc binding to the ezh2 gene promoter region was increased in the gp120M-treated rat spinal dorsal horn, and that intrathecal administration of antisense ODN against cMyc (AS-cMyc) reversed the increased enrichment of cMyc. Enrichment of trimethylation of histone 3 on lysine residue 27 (H3K27me3; an epigenetic mark associated with the downregulation of gene expression) binding to the sirt3 gene promoter region was upregulated in the gp120M-treated rat spinal dorsal horn; that intrathecal GSK126 reversed the increased enrichment of H3K27me3 in the sirt3 gene promoter. Luciferase reporter assay demonstrated that cMyc mediated ezh2 gene transcription at the ezh2 gene promoter region, and that H3K27me3 silenced sirt3 gene transcription at the gene promoter region. CONCLUSION:These results demonstrated that spinal Sirt3 decrease in gp120M-induced neuropathic pain was mediated by cMyc-EZH2/H3K27me3 activity in an epigenetic manner. This study provided new insight into the mechanisms of neuropathic pain in HIV patients with chronic opioids.

Purpose: To conduct a genome-wide association study (GWAS) of individuals with neuropathic ocular pain (NOP) symptoms to identify genomic variants that may predispose to NOP development. Design: Prospective study of individuals with NOP. Participants: Three hundred twenty-nine patients recruited from the Miami Veterans Affairs eye clinic. Methods: The Neuropathic Pain Symptom Inventory modified for the eye (NPSI-Eye) was completed to calculate a NPSI-Eye-Sub-Score (summed ratings of burning and wind sensitivity) as an indicator of NOP severity. A GWAS was performed for the NPSI-Eye-Sub-Score with a significance threshold of P < 5 x 10-8. A gene-based analysis was performed using the multimarker analysis of genomic annotation software (in the functional mapping and annotation of GWAS online platform). The 13 865 778 single nucleotide polymorphisms (SNPs) from our GWAS analysis were mapped to 10834 protein coding genes, and significant genes were run through gene set enrichment analysis. Main Outcome Measures: Identification of SNPs and protein products that may be associated with the development of NOP. Results: One hundred seventy-one SNPs reached a threshold of P < 10(-5), of which 10 SNPs reached the suggestive level of significance of P < 5 x 10(-7) and 1 SNP met our genome-wide significance threshold of P < 5 x 10(-8). This lead SNP, rs140293404 (P = 1.23 x 10(-8)), is an intronic variant found within gene ENSG00000287251 coding for transcript ENST00000662732.1. Rs140293404 is in linkage disequilibrium with exon variant rs7926353 (r2 > 0.8) within ENSG00000279046 coding for transcript ENST00000624288.1. The most significant genes from gene-based tests were matrix metalloproteinase-19 (MMP19) (P = 1.12 x 10(-5)), zinc finger RNA-binding motif and serine/arginine rich-1 (ZRSR1) (P = 1.48 x 10(-4)), CTC-487M23.8 (P = 1.79 x 10(-4)), receptor expression-enhancing protein-5 (REEP5) (P = 2.36 x 10(-4)), and signal recognition particle-19 (SRP19) (P = 2.56 x 10(-4)). From gene set enrichment analysis, the sensory perception (false discovery rate = 6.57 x 10(-3)) and olfactory signaling (false discovery rate = 1.63 x 10(-2)) pathways were enriched with the most significant genes. Conclusions: Our GWAS revealed genes with protein products that may impact sensory perception, lending biological plausibility to a role for SNPs identified by our GWAS in the development of NOP. A better under-standing of the biological relevance of these genes and pathways in the pathophysiology associated with NOP may facilitate future novel mechanism-based treatments.

Chronic pain is common and inadequately treated, making the development of safe and effective analgesics a high priority. Our previous data indicate that carbonic anhydrase-8 (CA8) expression in dorsal root ganglia (DRG) mediates analgesia via inhibition of neuronal ER inositol trisphosphate receptor-1 (ITPR1) via subsequent decrease in ER calcium release and reduction of cytoplasmic free calcium, essential to the regulation of neuronal excitability. This study tested the hypothesis that novel JDNI8 replication-defective herpes simplex-1 viral vectors (rdHSV) carrying a CA8 transgene (vHCA8) reduce primary afferent neuronal excitability. Whole-cell current clamp recordings in small DRG neurons showed that vHCA8 transduction caused prolongation of their afterhyperpolarization (AHP), an essential regulator of neuronal excitability. This AHP prolongation was completely reversed by the specific Kv7 channel inhibitor XE-991. Voltage clamp recordings indicate an effect via Kv7 channels in vHCA8-infected small DRG neurons. These data demonstrate for the first time that vHCA8 produces Kv7 channel activation, which decreases neuronal excitability in nociceptors. This suppression of excitability may translate in vivo as non-opioid dependent behavioral- or clinical analgesia, if proven behaviorally and clinically.

BACKGROUND: Recent clinical research suggests that repeated use of opioid pain medications can increase neuropathic pain in people living with human immunodeficiency virus (HIV; PLWH). Therefore, it is significant to elucidate the exact mechanisms of HIV-related chronic pain. HIV infection and chronic morphine induce proinflammatory factors, such as tumor necrosis factor (TNF)α acting through tumor necrosis factor receptor I (TNFRI). HIV coat proteins and/or chronic morphine increase mitochondrial superoxide in the spinal cord dorsal horn (SCDH). Recently, emerging cytoplasmic caspase-11 is defined as a noncanonical inflammasome and can be activated by reactive oxygen species (ROS). Here, we tested our hypothesis that HIV coat glycoprotein gp120 with chronic morphine activates a TNFRI-mtROS-caspase-11 pathway in rats, which increases neuroinflammation and neuropathic pain. METHODS: Neuropathic pain was induced by repeated administration of recombinant gp120 with morphine (gp120/M) in rats. Mechanical allodynia was assessed using von Frey filaments, and thermal latency using hotplate test. Protein expression of spinal TNFRI and cleaved caspase-11 was examined using western blots. The image of spinal mitochondrial superoxide was examined using MitoSox Red (mitochondrial superoxide indicator) image assay. Immunohistochemistry was used to examine the location of TNFRI and caspase-11 in the SCDH. Intrathecal administration of antisense oligodeoxynucleotide (AS-ODN) against TNFRI, caspase-11 siRNA, or a scavenger of mitochondrial superoxide was given for antinociceptive effects. Statistical tests were done using analysis of variance (1- or 2-way), or 2-tailed t test. RESULTS: Intrathecal gp120/M induced mechanical allodynia and thermal hyperalgesia lasting for 3 weeks ( P < .001). Gp120/M increased the expression of spinal TNFRI, mitochondrial superoxide, and cleaved caspase-11. Immunohistochemistry showed that TNFRI and caspase-11 were mainly expressed in the neurons of the SCDH. Intrathecal administration of antisense oligonucleotides against TNFRI, Mito-Tempol (a scavenger of mitochondrial superoxide), or caspase-11 siRNA reduced mechanical allodynia and thermal hyperalgesia in the gp120/M neuropathic pain model. Spinal knockdown of TNFRI reduced MitoSox profile cell number in the SCDH; intrathecal Mito-T decreased spinal caspase-11 expression in gp120/M rats. In the cultured B35 neurons treated with TNFα, pretreatment with Mito-Tempol reduced active caspase-11 in the neurons. CONCLUSIONS: These results suggest that spinal TNFRI-mtROS-caspase 11 signal pathway plays a critical role in the HIV-associated neuropathic pain state, providing a novel approach to treating chronic pain in PLWH with opioids.

Dry eye (DE) disease is a multifactorial, chronic condition with a prevalence of 5% to 30%.1 Dry eye symptoms are a frequent presenting report to eye clinics and can include sensations of dryness, as well as ocular pain (described as burning, aching, and irritation) and vision-related disturbances. Dry eye symptoms affect quality of life because they reduce the ability to work and carry out activities of daily living.1 Of note, DE symptoms are often disparate from DE signs, which include decreased tear production, increased tear evaporation, and inflammation, among others.

Background: Dysfunction at the ocular system via nociceptive or neuropathic mechanisms can lead to chronic ocular pain. While many studies have reported on responses to treatment for nociceptive pain, fewer have focused on neuropathic ocular pain. This retrospective study assessed clinical responses to pain treatment modalities in individuals with neuropathic component ocular surface pain. Methods: 101 individuals seen at the University of Miami Oculofacial Pain Clinic from January 2015 to August 2021 with ≥3 months of clinically diagnosed neuropathic pain were included. Patients were subcategorized (postsurgical, post-traumatic, migraine-like, and laterality) and self-reported treatment outcomes were assessed (no change, mild, moderate, or marked improvement). One-way ANOVA (analysis of variance) was used to examine relationships between follow up time and number of treatments attempted with pain improvement, and multivariable logistic regression was used to assess which modalities led to pain improvement. Results: The mean age was 55 years, and most patients were female (64.4%) and non-Hispanic (68.3%). Migraine-like pain (40.6%) was most common, followed by postsurgical (26.7%), post-traumatic (16.8%) and unilateral pain (15.8%). The most common oral therapies were α2δ ligands (48.5%), the m common topical therapies were autologous serum tears (20.8%) and topical corticosteroids (19.8%), and the most common adjuvant was periocular nerve block (24.8%). Oral therapies reduced pain in post-traumatic (81.2%), migraine-like (73%), and unilateral (72.7%) patients, but only in a minority of postsurgical (38.5%) patients. Similarly, topicals improved pain in post-traumatic (66.7%), migraine-like (78.6%), and unilateral (70%) compared to postsurgical (43.7%) patients. Non-oral/topical adjuvants reduced pain in postsurgical (54.5%), post-traumatic (71.4%), and migraine-like patients (73.3%) only. Multivariable analyses indicated migraine-like pain improved with concomitant oral α2δ ligands and adjuvant therapies, while postsurgical pain improved with topical anti-inflammatories. Those with no improvement in pain had a shorter mean follow-up (266.25 ± 262.56 days) than those with mild (396.65 ± 283.44), moderate (652 ± 413.92), or marked improvement (837.93 ± 709.35) ( p < 0.005). Identical patterns were noted for number of attempted medications. Conclusion: Patients with migraine-like pain frequently experienced pain improvement, while postsurgical patients had the lowest response rates. Patients with a longer follow-up and who tried more therapies experienced more significant relief, suggesting multiple trials were necessary for pain reduction.

PURPOSE:Ocular pain is a debilitating condition that is challenging to treat as therapies that target the ocular surface are often ineffective. We previously reported a short-term reduction in ocular pain after one periocular transcutaneous electrical nerve stimulation (TENS) session. The current study aims to elucidate the long-term effect of TENS on ocular pain.MATERIALS AND METHODS:Fourteen individuals with eye pain were identified as candidates for a TENS device (RS Medical, Vancouver) for home use after a successful trial in clinic between February 2018 and July 2019 at the Miami Veterans Administration Hospital or University of Miami. Ten of the 14 patients were included in this retrospective review, based on the inclusion of receiving and using the device for a minimum of three months. The median age of the ten patients was 47.5 years, range 32-73 years, and eight were male. The main outcome measures were 1) frequency of long-term integration of TENS into ocular pain management and 2) patient reported ocular pain intensity (0-10) pre- vs. post-treatment.RESULTS:Patients reported an initial median use of the device 14.0 times per week and over time reducing the frequency to 3.0 times per week. All reported that the TENS unit was successfully incorporated into their ocular pain management routine for at least three months (median duration of use 6.5 months, range 3-14 months). Nine of ten patients reported subjective pain reduction with use of the TENS device at home. Overall, pain intensity decreased by approximately 27.4% (mean rank = 5.6, Z = -2.1, p = 0.02) post- vs. pre-treatment. No adverse events associated with TENS were reported in any patient.CONCLUSION:Our preliminary data suggest that TENS can be integrated into the long-term management of ocular pain with improvements in overall pain intensity.

PURPOSE:Individuals receiving botulinum toxin A (BoNT-A) injections in the head and neck for migraine treatment have reported decreases in photophobia and sensations of dryness, independent of ocular surface parameters. We hypothesized that patients without migraine but with similar ocular neuropathic-like symptoms would also experience symptomatic improvement with periocular BoNT-A injections, independent of ocular surface changes.OBSERVATIONS:We identified four individuals without a history of migraine but with neuropathic ocular pain (symptoms of dryness, burning, and photophobia that were out of proportion to ocular surface findings and unresponsive to ongoing dry eye (DE) therapies). Individuals underwent 1 session of periocular BoNT-A injections. Validated questionnaires (Visual Light Sensitivity Questionnaire-8, Dry Eye Questionnaire-5) assessed photophobia and DE symptoms pre- and 1-month post-injections. All four reported improvements in frequency and severity of photophobia and eye discomfort following BoNT-A injections. Tear film parameters (phenol red thread test, tear break-up time, corneal staining, and Schirmer test) and eyelid (palpebral fissure height and levator palpebrae superioris function) and eyebrow (position) anatomy were also evaluated before and after injections. Despite a unanimous improvement in symptoms, there were no consistent changes in ocular surface parameters with BoNT-A injections across individuals.CONCLUSIONS:Periocular BoNT-A shows promise in reducing photophobia and sensations of dryness in individuals with neuropathic-like DE symptoms without a history of migraine, independent of tear film, eyelid, or eyebrow parameters.

Intracellular calcium is critical in orchestrating neuronal excitability and analgesia. Carbonic anhydrase-8 (CA8) regulates intracellular calcium signaling through allosteric inhibition of neuronal inositol trisphosphate receptor 1 (ITPR1) to produce profound analgesia. Recently, we reported the "G" allele at rs6471859 represents cis-eQTL regulating alternative splicing of a 1697 bp transcript (CA8-204G) with a retained intron, alternative polyadenylation site and a new stop codon producing a functional 26 kDa peptide with an extended exon 3. In this study we show the reversion mutation (G to C) at rs6471859 within the CA8-204G expression vector also produced a stable 1697 bp transcript (CA8-204C) coding for a smaller peptide (~ 22 kDa) containing only the first three CA8 exons. Surprisingly, this peptide inhibited ITPR1 (pITPR1) activation, ITPR1-mediated calcium release in vitro; and produced profound analgesia in vivo. This is the first report showing CA8-204C codes for a functional peptide sufficient to regulate calcium signaling and produce profound analgesia.

Purpose: Osteoarthritis (OA) is a degenerative disease marked by breakdown of joint cartilage and associated bony changes. A dominant symptom is pain, which can become severe to the point where the patient is a candidate for joint replacement surgery. Although a wide range of analgesics and therapeutics are available, pain frequently remains an intractable problem. Even after total knee replacement, chronic knee pain has been reported in up to a third of patients. Resiniferatoxin (RTX) is a potent TRPV1 calcium channel agonist. RTX exposure results in prolonged calcium influx and ablation of TRPV1-positive nerve endings. In preclinical osteoarthritis models, RTX treatment leads to selective neurolysis of TRPV1-expressing pain sensory fibers and leaves sensory and motor neuron functions intact. We report on the preliminary safety and efficacy results from a phase 1B trial of resiniferatoxin administered intra-articularly as a one-time injection in subjects with moderate to severe pain due to knee osteoarthritis. Methods: In this multicenter, randomized, double-blind, placebo-controlled study, eligible subjects aged 35-85 years, with baseline pain score in the index knee of ≥5 but ≤9 (WOMAC pain subscale question A1) were treated with a one-time intra-articular dose of resiniferatoxin at escalating dose level cohorts of 5, 12.5, 20 and 30 mcg in 5 or 10 mL of saline, or saline placebo. For each 8-subject cohort the first subject received open-label RTX. Upon confirmation of safety in this sentinel subject, the remaining 7 subjects (5 RTX: 2 PBO) were enrolled in a blinded fashion. After confirmation of safety at each dose level by an independent DMC, the next higher dose level was opened for enrollment. Safety and efficacy data were collected over a twelve-week period. Subjects could be unblinded after a protocol-specified time period. Additional follow-up to 52 weeks was optional. Efficacy was assessed using the subject reported WOMAC and NPRS pain scores. Results: Enrollment of all planned dose escalation cohorts is complete, with 30 subjects receiving RTX and 10 receiving placebo. 70% are female and 30% are male. Median age is 62 years (range 44-83), and baseline WOMAC A1 score was mean 6.5 (S.D. 1.4). No dose-limiting toxicities were reported, and the maximum tolerated dose was not reached. The most frequently reported treatment-emergent adverse events were procedure-associated pain (post-procedural pain), which was reported in 80% of placebo subjects and in 100% of RTX subjects. This procedure-associated pain was reported as mild in severity in all placebo subjects, and mild in 73% and moderate in 27% of RTX subjects. Procedure-associated pain was managed with IV fentanyl, PO oxycodone, and other analgesics on the day of the injection. Typically, the pain subsided before being discharged that same day and subsided within 24 hours in all subjects. Other adverse events (reported in at least 2 RTX-treated subjects) were nausea (43%), vomiting and arthralgia (17%), hypertension and headache (10%) and hypoaesthesia (7%). Most events were mild, the few moderate events were of short duration; none were severe. There was no apparent relationship between adverse events and dose levels. In the secondary endpoint of efficacy, reduction in subject reported WOMAC A1 pain scores was observed at most dose levels. The difference in the mean score for WOMAC A1 (pain on walking on flat surface) at week 12 between the placebo subjects and RTX treated subjects expressed as the least squares mean difference (LSMD) in change from baseline relative to placebo, ranged from -0.04 to -2.63 points depending on the dose level cohort. By mixed model repeated measures (MMRM) analysis, the greatest pain reduction was observed at the 12.5 mcg dose (LSMD) versus placebo at 12 weeks of -2.63 by WOMAC A1 score (p = 0.0311, N=6) and -14.58 by WOMAC A pain index (p = 0.0134, N = 6). Compared to baseline pain by WOMAC A1, >70% reduction in the pain was achieved in 50% of pooled RTX-treated subjects and in 83% of the subjects at the 12.5 mcg dose. Pain reduction by RTX as assessed by the daily subject-reported NPRS pain scores were consistent with the WOMAC A1 data. Of the subjects dosed with RTX who have provided voluntary long-term follow-up, 3 of 4 subjects who have reached one year have maintained response. Conclusions: Resiniferatoxin demonstrated safety when given as one-time intra-articular injection up to the planned highest dose of 30 mcg. Preliminary efficacy was also observed. Anecdotal long-term follow up suggests sustained pain relief beyond Day 365. The clinical trial remains open to expansion cohorts to assess further the safety and efficacy at candidate doses to be implemented in future trials.

Syndromic sensorineural hearing loss is multigenic and associated with malformations of the ear and other organ systems. Herein we describe a child admitted to the NIH Undiagnosed Diseases Program with global developmental delay, sensorineural hearing loss, gastrointestinal abnormalities, and absent salivation. Next-generation sequencing revealed a uniparental isodisomy in chromosome 5, and a 22 kb homozygous deletion in SLC12A2, which encodes for sodium, potassium, and chloride transporter in the basolateral membrane of secretory epithelia. Functional studies using patient-derived fibroblasts showed truncated SLC12A2 transcripts and markedly reduced protein abundance when compared with control. Loss of Slc12a2 in mice has been shown to lead to deafness, abnormal neuronal growth and migration, severe gastrointestinal abnormalities, and absent salivation. Together with the described phenotype of the Slc12a2-knockout mouse model, our results suggest that the absence of functional SLC12A2 causes a new genetic syndrome and is crucial for the development of auditory, neurologic, and gastrointestinal tissues.

Background Many individuals with migraine report symptoms of dry eye (DE). However, it is not known whether DE profiles are similar between individuals with and without migraine. To bridge this gap, we evaluated symptoms and signs of DE, including symptoms suggestive of nerve dysfunction, in a large group of individuals with DE symptoms, and compared profiles between individuals with migraine and those without migraine or headache. Methods Prospective cross-sectional study of individuals with DE symptoms seen at the Miami VA. Results Of 250 individuals, 31 met International Classification of Headache Disorders criteria for migraine based on a validated screen. Individuals with migraine were significantly younger (57 vs 62 years) and more likely to be female (26% vs 6%) than controls. Individuals with migraine had more severe DE symptoms and ocular pain compared with controls (mean Ocular Surface Disease Index 53.93 ± 21.76 vs 36.30 ± 22.90, p=0.0001; mean Neuropathic Pain Symptom Inventory modified for the Eye 39.39 ± 23.33 vs 21.86 ± 20.17, p=0.0001). The difference in symptom profile occurred despite similar ocular surface parameters between the groups. Conclusions Individuals with migraine had a different DE symptom yet a similar DE sign profile when compared with controls without migraine. This suggests that DE symptoms in individuals with migraine may be driven by nerve dysfunction as opposed to ocular surface abnormalities.

Neuropathic pain (NeuP) arises due to injury of the somatosensory nervous system and is both common and disabling, rendering an urgent need for non-addictive, effective new therapies. Given the high evolutionary conservation of pain, investigative approaches from Drosophila mutagenesis to human Mendelian genetics have aided our understanding of the maladaptive plasticity underlying NeuP. Successes include the identification of ion channel variants causing hyper-excitability and the importance of neuro-immune signaling. Recent developments encompass improved sensory phenotyping in animal models and patients, brain imaging, and electrophysiology-based pain biomarkers, the collection of large well-phenotyped population cohorts,neurons derived from patient stem cells, and high-precision CRISPR generated genetic editing. We will discuss how to harness these resources to understand the pathophysiological drivers of NeuP, define its relationship with comorbidities such as anxiety, depression, and sleep disorders, and explore how to apply these findings to the prediction, diagnosis, and treatment of NeuP in the clinic.

BACKGROUND: The X-chromosome gene USP9X encodes a deubiquitylating enzyme that has been associated with neurodevelopmental disorders primarily in female subjects. USP9X escapes X inactivation, and in female subjects de novo heterozygous copy number loss or truncating mutations cause haploinsufficiency culminating in a recognizable syndrome with intellectual disability and signature brain and congenital abnormalities. In contrast, the involvement of USP9X in male neurodevelopmental disorders remains tentative. METHODS: We used clinically recommended guidelines to collect and interrogate the pathogenicity of 44 USP9X variants associated with neurodevelopmental disorders in males. Functional studies in patient-derived cell lines and mice were used to determine mechanisms of pathology. RESULTS: Twelve missense variants showed strong evidence of pathogenicity. We define a characteristic phenotype of the central nervous system (white matter disturbances, thin corpus callosum, and widened ventricles); global delay with significant alteration of speech, language, and behavior; hypotonia; joint hypermobility; visual system defects; and other common congenital and dysmorphic features. Comparison of in silico and phenotypical features align additional variants of unknown significance with likely pathogenicity. In support of partial loss-of-function mechanisms, using patient-derived cell lines, we show loss of only specific USP9X substrates that regulate neurodevelopmental signaling pathways and a united defect in transforming growth factor signaling. In addition, we find correlates of the male phenotype in Usp9x brain-specific knockout mice, and further resolve loss of hippocannpal-dependent learning and memory. CONCLUSIONS: Our data demonstrate the involvement of USP9X variants in a distinctive neurodevelopmental and behavioral syndrome in male subjects and identify plausible mechanisms of pathogenesis centered on disrupted transforming growth factor beta signaling and hippocampal function.

PURPOSE There is a recognition that nerve dysfunction can contribute to chronic ocular pain in some individuals. However, limited data are available on how to treat individuals with a presumed neuropathic component to their ocular pain. As such, the purpose of this study was to examine the efficacy of our treatment approaches to this entity. METHODS A retrospective review of treatments and outcomes in individuals with chronic ocular pain that failed traditional therapies. RESULTS We started eight patients on an oral gabapentinoid (gabapentin and/or pregabalin) as part of their pain regimen (mean age 46 years, 50% women). Two individuals reported complete ocular pain relief with a gabapentinoid, in conjunction with their topical and oral medication regimen. Three individuals noted significant improvements, one slight improvement, and two others no improvement in ocular pain with gabapentin or pregabalin. We performed periocular nerve blocks (4 mL of 0.5% bupivacaine mixed with 1 mL of 80 mg/mL methylprednisolone acetate) targeting the periocular nerves (supraorbital, supratrochlear, infratrochlear, and infraorbital) in 11 individuals (mean age 54 years, 36% women), 10 of whom had previously used a gabapentinoid without ocular pain improvement. Seven individuals experienced pain relief after nerve blocks that lasted from hours to months and four failed to benefit. Five of the individuals who experienced pain relief underwent repeat nerve blocks, weeks to months later. CONCLUSIONS Approaches used to treat chronic pain outside the eye can be applied to ocular pain that is not responsive to traditional therapies.

Mutations in the torsinA-interacting protein 1 (TOR1AIP1) gene result in a severe muscular dystrophy with minimal literature in the pediatric population. We review a case of TOR1AIP1 gene mutation in a 16-year-old Caucasian female with a long history of muscle weakness. Extensive clinical workup was performed and MRI at time of initial presentation demonstrated no significant muscular atrophy with heterogenous STIR hyperintensity of the lower extremity muscles. MRI findings seven years later included extensive atrophy of the lower extremities, with severe progression, including the gluteal muscles, iliopsoas, rectus femoris, and obturator internus. There was also significant atrophy of the rectus abdominis and internal and external oblique muscles, and iliacus muscles. The MRI findings showed more proximal involvement of lower extremities and no atrophy of the tibialis anterior, making TOR1AIP1 the more likely genetic cause. Muscle biopsy findings supported TOR1AIP1 limb-girdle muscular dystrophy. Though rare, TOR1AIP1 gene mutation occurs in pediatric patients and MRI can aid in diagnosis and help differentiate from other types of muscular dystrophy. Genetic and pathology workup is also crucial to accurate diagnosis and possible treatment of these patients.