Association between motor neuron disease and HIV infection: A systematic review of case reports.

BACKGROUND: Motor neuron disease (MND) is a well-known group of neurodegenerative diseases, with amyotrophic lateral sclerosis (ALS) being the most common form. Since 1985, a possible association between MND/ALS and HIV infection has been described. METHODS: We performed a systematic review of case reports and case series involving people living with HIV with MND/ALS through PubMed, Bireme, Embase, and Lilacs databases. The risk of bias was assessed using the Joanna Briggs Institute (JBI) Critical Appraisal Tool for Case Reports. RESULTS: We analyzed 36 articles presenting 88 cases. The mean age was 41.6 years. Antiretroviral therapy (ART) was used by 89.8% and riluzole by 16.9%. First signs and symptoms were similarly present on cervical/upper (25%) and lumbosacral/lower limbs (23.9%), mostly with fasciculations (69.8%) and hyperreflexia (58.8%). MND had a progressive course in 32.9% patients and a clinical improve in 54.6% following ART. The mean survival of the 32 patients who died was 12.3 months and the mean survival of the living patients was 62 months. Respiratory failure was the main cause of death (35.7%). CONCLUSIONS: MND/ALS may present differently in the people living with HIV as a rapidly progressive disease in younger people but with the potential to improve weakness and survival through antiretroviral therapy.

Exploring the Impact of Personalized Physical Therapy on a Patient With Motor Neuron Disorder: A Case Study.

This case study examines the effect of a tailor-made physiotherapy regimen on an 85-year-old male patient who was suffering from bulbar motor neuron disease (MND) and had a history of stroke and COVID-19. The physiotherapy plan was designed to strategically address the patient's respiratory issues, generalized weakness affecting limb muscles, and speech and swallowing difficulties. Frequent evaluations made it possible to adjust the treatment plan, emphasizing a holistic strategy to improve the patient's overall quality of life. Improvements in scores on multiple functional scales and manual muscle testing were shown by outcome measures and follow-up evaluations. This case emphasizes how important customized physiotherapy is for maximizing functional outcomes and enhancing the quality of life for patients dealing with the complicated conditions of bulbar MND.

Development and Evaluation of the Telehealth in Motor Neuron Disease System: The TIME Study Protocol.

BACKGROUND: For more responsive care provision for motor neuron disease and caregivers, a digital system called Telehealth in MND-Care (TiM-C) was created. TiM-C sends regular symptom questionnaires to users; their responses are sent to health care professionals (HCPs). To enable people with motor neuron disease to participate in research studies more easily, a parallel platform was developed from TiM-C, called Telehealth in MND-Research (TiM-R). TiM-R can advertise studies, collect data, and make them available to MND researchers. OBJECTIVE: This study has 4 work packages (WPs) to facilitate service approval, codevelop the TiM systems, and evaluate the service. Each WP aims to understand (1) what helps and hinders the approval of the TiM-C system as a National Health Service; (2) what aspects of MND care and research are currently unmet and can be addressed through the TiM-C and TiM-R systems; (3) how TiM-C influences MND care, from the perspective of people with motor neuron disease, their caregivers, and HCPs; and (4) the costs and benefits associated with TiM-C. METHODS: WP1 will use semistructured interviews with 10-15 people involved in the approval of TiM-C to understand the barriers and facilitators to governance processes. WP2 will use individual and group interviews with 25-35 users (people with motor neuron disease, caregivers, HCPs, MND researchers, and industry) of TiM-C and TiM-R to understand the current unmet needs of these user groups and how TiM services can be developed to meet these needs. WP3 will use a process evaluation involving 5 elements; local context, engagement, user experiences, service impact, and mechanisms of action. A range of methods, including audits, analysis of routine data, questionnaires, interviews, and observations will be used with people with motor neuron disease, caregivers, and HCPs, both those using the system and those who declined the service when invited. WP4 will use data collected through the process evaluation and known costs to conduct a cost-consequence and budget impact analysis to explore the cost-benefit of the TiM-C service. Most data collected will be qualitative, with thematic and framework analysis used to develop themes from transcripts and observations. Descriptive statistics or t tests and chi-square tests will be used to describe and analyze quantitative data. RESULTS: This study has received ethical approval and has begun recruitment in 1 site. Further, 13 specialist MND centers will adopt TiM-C and the TIME study, beginning in July 2024. The study will conclude in November 2026 and a final report will be produced 3 months after the completion date. CONCLUSIONS: This study will facilitate the implementation and development of TiM-C and TiM-R and fully evaluate the TiM-C service, enabling informed decision-making among health care providers regarding continued involvement and contribute to the wider literature relating to how technology-enabled care services can affect clinical care. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/57685.

Perspective role of Substance P in Amyotrophic Lateral Sclerosis: From neuronal vulnerability to neuroprotection.

The neuropeptide Substance P (SP) and its preferred Neurokinin1 Receptor (NK1R) are known to participate in the physiopathology of neurodegenerative diseases and mainly exert a neuroprotective role. In the present work, we have described the involvement of SP and NK1R in Amyotrophic Lateral Sclerosis (ALS). This was demonstrated by the detection of altered levels of SP in the brain, spinal cord and cerebrospinal fluid (CSF) of patients and preclinical models of ALS, and by its ability to inhibit excitotoxicity-induced neurodegeneration in ALS animal models. These data are supported by results indicating an excitatory effect of SP at the motor neuron (MN) level, which promotes locomotor activity. ALS patients are characterized by a differential susceptibility to MNs degeneration, since sphincters and extraocular muscles are classically spared. It is hypothesized that SP may play a role in the maintenance of the ocular system and the innervation of the pelvic floor by contributing directly or indirectly to the selective resistance of this subset of MNs.

Distinct Longitudinal Changes in EEG Measures Reflecting Functional Network Disruption in ALS Cognitive Phenotypes.

Amyotrophic lateral sclerosis (ALS) is characterised primarily by motor system degeneration, with clinical evidence of cognitive and behavioural change in up to 50% of cases. We have shown previously that resting-state EEG captures dysfunction in motor and cognitive networks in ALS. However, the longitudinal development of these dysfunctional patterns, especially in networks linked with cognitive-behavioural functions, remains unclear. Longitudinal studies on non-motor changes in ALS are essential to further develop our understanding of disease progression, improve care and enhance the evaluation of new treatments. To address this gap, we examined 124 ALS individuals with 128-channel resting-state EEG recordings, categorised by cognitive impairment (ALSci, n = 25), behavioural impairment (ALSbi, n = 58), or non-impaired (ALSncbi, n = 53), with 12 participants meeting the criteria for both ALSci and ALSbi. Using linear mixed-effects models, we characterised the general and phenotype-specific longitudinal changes in brain network, and their association with cognitive performance, behaviour changes, fine motor symptoms, and survival. Our findings revealed a significant decline in [Formula: see text]-band spectral power over time in the temporal region along with increased [Formula: see text]-band power in the fronto-temporal region in the ALS group. ALSncbi participants showed widespread ß-band synchrony decrease, while ALSci participants exhibited increased co-modulation correlated with verbal fluency decline. Longitudinal network-level changes were specific of ALS subgroups and correlated with motor, cognitive, and behavioural decline, as well as with survival. Spectral EEG measures can longitudinally track abnormal network patterns, serving as a candidate stratification tool for clinical trials and personalised treatments in ALS.

Autophagy, aging, and age-related neurodegeneration.

Autophagy is a conserved mechanism that degrades damaged or superfluous cellular contents and enables nutrient recycling under starvation conditions. Many neurodegeneration-associated proteins are autophagy substrates, and autophagy upregulation ameliorates disease in many animal models of neurodegeneration by enhancing the clearance of toxic proteins, proinflammatory molecules, and dysfunctional organelles. Autophagy inhibition also induces neuronal and glial senescence, a phenomenon that occurs with increasing age in non-diseased brains as well as in response to neurodegeneration-associated stresses. However, aging and many neurodegeneration-associated proteins and mutations impair autophagy. This creates a potentially detrimental feedback loop whereby the accumulation of these disease-associated proteins impairs their autophagic clearance, facilitating their further accumulation and aggregation. Thus, understanding how autophagy interacts with aging, senescence, and neurodegenerative diseases in a temporal, cellular, and genetic context is important for the future clinical application of autophagy-modulating therapies in aging and neurodegeneration.

Cognitive impairment in children with 5q-associated spinal muscular atrophy type 1: two case reports and the review of the literature.

Spinal muscular atrophy (SMA) is an autosomal recessive disease caused by mutations in the survival motor neuron 1 (SMN1) gene on chromosome 5, leading to the degeneration of lower motor neurons. There are few studies on cognitive impairment comorbid with SMA. Here, we report two cases of severe cognitive impairment in Chinese children with SMA type 1, marking the first such reports in this demographic. We propose that severe cognitive dysfunction may be a comorbidity of SMA. Clinicians should consider SMA in patients presenting with severe muscle weakness and atrophy accompanied by cognitive impairments, to avoid misdiagnosis and oversight.

Neuropathological spectrum of anti-IgLON5 disease and stages of brainstem tau pathology: updated neuropathological research criteria of the disease-related tauopathy.

Anti-IgLON5 disease is a unique condition that bridges autoimmunity and neurodegeneration. Since its initial description 10 years ago, an increasing number of autopsies has led to the observation of a broader spectrum of neuropathologies underlying a particular constellation of clinical symptoms. In this study, we describe the neuropathological findings in 22 patients with anti-IgLON5 disease from 9 different European centers. In 15 patients (68%), we observed a hypothalamic and brainstem-predominant tauopathy of varying severity in which the original research neuropathological criteria were readily applicable. This pathology was observed in younger patients (median age at onset 61 years) with a long disease duration (median 9 years). In contrast, in 7 (32%) patients, the originally described brainstem tauopathy was nearly absent or only minimal in the form of delicate threads, despite mild-to-moderate neurodegenerative features, consistent clinical symptoms and the presence of anti-IgLON5 antibodies in CSF and serum. These patients were older at onset (median 79 years) and had shorter disease duration (median < 1 year). Overall, about one-third of the patients showed concomitant TDP-43 pathology within the regions affected by tau pathology and/or neurodegeneration. Based on these observations and in view of the spectrum of the tau burden in the core regions involved in the disease, we propose a simple staging system: stage 1 mild neurodegeneration without overt or only minimal tau pathology, stage 2 moderate neurodegeneration and mild/ moderate tauopathy and stage 3 prominent neurodegeneration and tau pathology. This staging intends to reflect a potential (age- and time-dependent) progression of tau pathology, supporting the current notion that tau accumulation is a secondary phenomenon related to the presence of anti-IgLON5 antibodies in the CNS. Finally, we adapt the original research criteria of the anti-IgLON5 disease-related tauopathy to include the spectrum of pathologies observed in this larger postmortem series.

Fish That Fish for Fish-A Peculiar Location of "Fishing Motoneurons" in the Striated Frogfish Antennarius striatus.

In lophiform teleosts, the first dorsal fin has evolved as a specialized structure called the "illicium" equipped with the esca, which is a modified skin flap used to attract small fish for predation. The motor control system of the illicium, however, remained unknown. The present study investigated the innervation of muscles for the illicium and morphology of motoneurons innervating them in the striated frogfish Antennarius striatus. We found that the dorsal ramus of occipital nerve innervates the muscles. Motoneurons for the illicium are present in the dorsolateral zone of ventral horn at the medullo-spinal boundary level, forming a cluster somewhat distinct from other motoneurons of the ventral horn. Motoneurons for the second to fourth dorsal fins and pectoral fin were located in the ventrolateral and ventromedial zones of ventral horn, respectively, whereas those of the dorsal trunk muscle in the dorsomedial zone of ventral horn. Motoneurons for the first dorsal spine of white-spotted pygmy filefish were also investigated for species comparison and were found to locate in the ventrolateral zone of ventral horn, similarly to the motoneurons for the second to fourth dorsal fins of the frogfish. These results suggest that motoneurons for the illicium have become segregated from other motoneurons to be situated in an unusual dorsal position for a motoneuron pool of a dorsal fin, in concert with the evolution of specialized "fishing behavior" performed by the illicium.

Neuropalliative Care Needs Checklist for Motor Neuron Disease and Parkinson's Disease: A Biopsychosocial Approach.

Objectives: Neurodegenerative disorders necessitate comprehensive palliative care due to their progressive and irreversible nature. Limited studies have explored the comprehensive assessment needs of this population. This present study is designed to develop a checklist for evaluating the palliative care needs of individuals with motor neuron disease (MND) and Parkinson's disease (PD). Materials and Methods: The checklist was created through an extensive literature review and discussions with stakeholders in neuropalliative. Feedback from six field experts led to the finalisation of the checklist, which comprised 53 items addressing the unique biopsychosocial needs of MND and PD. Sixty patient-caregiver dyads receiving treatment in a tertiary referral care centre for neurology in south India completed the checklist. Results: People with MND had more identified needs with speech, swallowing, and communication, while people with PD reported needs in managing tremors, reduced movements, and subjective feelings of stiffness. People denying the severity of the illness was found to be a major psychosocial issue. The checklist addresses the dearth of specific tools for assessing palliative care needs in neurodegenerative disorders, particularly MND and PD. By incorporating disease-specific and generic items, the checklist offers a broad assessment of patients' multidimensional needs. Conclusion: This study contributes to the area of neuropalliative care by developing the neuropalliative care needs checklist (NPCNC) as a valuable tool for assessing the needs of individuals with neurodegenerative diseases. Future research should focus on refining and validating the NPCNC with larger and more diverse groups, applicability in different contexts, and investigating its sensitivity to changes over time.

Juvenile Amyotrophic Lateral Sclerosis: A Case Report of a Rare and Aggressive Presentation in a 22-Year-Old Filipino Male.

Amyotrophic Lateral Sclerosis (ALS) is a rare neurodegenerative disorder primarily affecting adults, but juvenile-onset ALS is exceptionally rare. We report a rare case of a 22-year-old Filipino male patient who exhibited early-onset weakness, muscle atrophy, and tongue fasciculations, followed by rapidly progressive dysphagia and respiratory distress. Electromyography - Nerve Conduction Velocity (EMG-NCV) findings showed evidence for a chronic, active predominantly motor neuronal-axonal loss type of neuropathy involving the tongue and limb muscles bilaterally consistent with a motor neuron disease. The patient was treated with riluzole with no significant improvement in symptoms. Despite multidisciplinary interventions, the disease rapidly progressed, highlighting the challenges in managing juvenile ALS cases. This case report emphasizes the importance of considering ALS in the differential diagnosis of progressive motor dysfunction in younger patients and the complexities involved in their care.

Mapping the Evidence for Measuring Energy Expenditure and Indicating Hypermetabolism in Motor Neuron Disease: A Scoping Review.

OBJECTIVE: To map the international methods used to measure energy expenditure of adults living with motor neuron disease (MND) and to highlight discrepancies when indicating hypermetabolism in the MND literature. BACKGROUND: A decline in the nutritional status of patients is associated with exacerbated weight loss and shortened survival. Assessments of energy expenditure, using a variety of methods, are important to ensure an adequate energy intake to prevent malnutrition-associated weight loss. Assessments of energy expenditure are also commonly used to indicate hypermetabolism in MND, although these approaches may not be optimal. METHODS: A protocol based on the Preferred Reporting Items for Systematic Reviews and Meta-analyses extension for Scoping Reviews Guidelines was developed. Three electronic databases (Medline [Ovid], CINAHL [EBSCO], and Web of Science) were exhaustively searched. Identified publications were systematically screened according to predefined PICOS eligibility criteria. The primary outcome was the identification of methods used to measure energy expenditure in MND. The secondary outcome was the identification of applications of energy expenditure assessments to indicate hypermetabolism in MND. RESULTS: Thirty-two observational primary research publications were identified. Thirteen (40.6%) were longitudinal in design, with data on repeated measurements of energy expenditure presented in 3 (9.4%). Thirteen (40.6%) were case-control studies, of which 11 use a matched control group. Pulmonary function was used to assess eligibility in 10 publications. Energy expenditure was measured using indirect calorimetry (IC) in 31 studies. Discrepancies in the durations of fasted, measurement, and washout periods were observed. Of all included publications, 50% used assessments of resting energy expenditure to identify hypermetabolism. Bioelectrical impedance analysis was used to assess body composition alongside energy expenditure in 93.8% of publications. CONCLUSIONS: Resting energy expenditure is most frequently measured using an open-circuit IC system. However, there is a lack of a standardized, validated protocol for the conduct and reporting of IC and metabolic status in patients with MND.

Paraneoplastic Motor Neuron Disease in a Patient With Sigmoid Colon Adenocarcinoma: A Case Report.

Paraneoplastic neurological syndromes (PNS) are a rare and diverse group of disorders caused by immune-mediated effects of malignancies. These syndromes are very rare and often present diagnostic and therapeutic challenges. Motor neuron disease as a paraneoplastic condition is particularly uncommon, especially in association with gastrointestinal malignancies like sigmoid colon adenocarcinoma. A 62-year-old male with type 2 diabetes mellitus (T2DM) presented with chronic diarrhea and a three-year history of progressive bilateral limb weakness. Initial symptoms were attributed to diabetic neuropathy, but the rapid progression and severity warranted further investigation. Neurological examination revealed hypotonia, muscle wasting, and absent reflexes in all four limbs. Diagnostic tests, including electromyography (EMG) and nerve conduction studies, confirmed motor sensory axonal neuropathy. A colonoscopy revealed a mass in the sigmoid colon, and a biopsy confirmed adenocarcinoma. The patient was managed with surgical resection of the tumor, adjuvant chemotherapy, and immunomodulatory treatments, resulting in the stabilization of neurological symptoms. This case highlights the importance of considering paraneoplastic syndromes in patients with unexplained neurological symptoms, particularly when a malignancy is suspected or known. Early recognition and a multidisciplinary approach are crucial for improving patient outcomes. Further research is needed to understand the pathophysiological mechanisms and develop sensitive biomarkers for early detection.

Targeting EGLN2/PHD1 protects motor neurons and normalizes the astrocytic interferon response.

Neuroinflammation and dysregulated energy metabolism are linked to motor neuron degeneration in amyotrophic lateral sclerosis (ALS). The egl-9 family hypoxia-inducible factor (EGLN) enzymes, also known as prolyl hydroxylase domain (PHD) enzymes, are metabolic sensors regulating cellular inflammation and metabolism. Using an oligonucleotide-based and a genetic approach, we showed that the downregulation of Egln2 protected motor neurons and mitigated the ALS phenotype in two zebrafish models and a mouse model of ALS. Single-nucleus RNA sequencing of the murine spinal cord revealed that the loss of EGLN2 induced an astrocyte-specific downregulation of interferon-stimulated genes, mediated via the stimulator of interferon genes (STING) protein. In addition, we found that the genetic deletion of EGLN2 restored this interferon response in patient induced pluripotent stem cell (iPSC)-derived astrocytes, confirming the link between EGLN2 and astrocytic interferon signaling. In conclusion, we identified EGLN2 as a motor neuron protective target normalizing the astrocytic interferon-dependent inflammatory axis in vivo, as well as in patient-derived cells.

Understanding the Role of the SMN Complex Component GEMIN5 and Its Functional Relationship with Demethylase KDM6B in the Flunarizine-Mediated Neuroprotection of Motor Neuron Disease Spinal Muscular Atrophy.

Dysregulated RNA metabolism caused by SMN deficiency leads to motor neuron disease spinal muscular atrophy (SMA). Current therapies improve patient outcomes but achieve no definite cure, prompting renewed efforts to better understand disease mechanisms. The calcium channel blocker flunarizine improves motor function in Smn-deficient mice and can help uncover neuroprotective pathways. Murine motor neuron-like NSC34 cells were used to study the molecular cell-autonomous mechanism. Following RNA and protein extraction, RT-qPCR and immunodetection experiments were performed. The relationship between flunarizine mRNA targets and RNA-binding protein GEMIN5 was explored by RNA-immunoprecipitation. Flunarizine increases demethylase Kdm6b transcripts across cell cultures and mouse models. It causes, in NSC34 cells, a temporal expression of GEMIN5 and KDM6B. GEMIN5 binds to flunarizine-modulated mRNAs, including Kdm6b transcripts. Gemin5 depletion reduces Kdm6b mRNA and protein levels and hampers responses to flunarizine, including neurite extension in NSC34 cells. Moreover, flunarizine increases the axonal extension of motor neurons derived from SMA patient-induced pluripotent stem cells. Finally, immunofluorescence studies of spinal cord motor neurons in Smn-deficient mice reveal that flunarizine modulates the expression of KDM6B and its target, the motor neuron-specific transcription factor HB9, driving motor neuron maturation. Our study reveals GEMIN5 regulates Kdm6b expression with implications for motor neuron diseases and therapy.

Influences of Specialist Palliative Care Team Input, Advance Care Planning, Non-Invasive Ventilation and Gastrostomy Status on Unscheduled Hospital Admissions and Place of Death for People with Motor Neuron Disease: A Retrospective Cohort Analysis.

OBJECTIVE: Motor neuron disease is a rapidly progressing neurological condition. People with life-limiting conditions generally prefer to die at home and avoid hospital admissions, with Specialist Palliative Care Team involvement often pivotal. Our aim was to investigate the role of advance care planning, Specialist Palliative Care Team input and other relevant variables on place of death and unscheduled hospital admissions in a Scottish population of people with motor neuron disease. Methods: National CARE-MND audit data, primary and secondary care data, and local Palliative Care records were interrogated. Chi-square, point-biserial correlation and binary logistic regression analysed associations (p < 0.05 statistically significant). Participants (188) were deceased, having a verified motor neuron disease diagnosis between 2015-2017, diagnosis occurring ≥28 days before death. Results: Advance care planning and Specialist Palliative Care Team input of ≥28 days were associated with increased odds of dying outside hospital (BLR:OR 3.937, CI 1.558-9.948, p = 0.004 and OR 2.657, CI 1.135-6.222, p = 0.024 respectively). Non-invasive ventilation decreased the odds of dying outside hospital (BLR:OR 0.311, CI 0.124-0.781, p = 0.013). Having a gastrostomy increased odds of ≥1 admissions in the last year of life (BLR:OR 5.142, CI 1.715-15.417, p = 0.003). Statistical significance was retained with removal of gastrostomy-related complications. Conclusion: Early Specialist Palliative Care input and advance care planning may increase the likelihood of death outside of hospital for persons with motor neuron disease. Further research is warranted into barriers of facilitating death outside of hospital with home non-invasive ventilation use and the association between gastrostomy status and unscheduled admissions.

ALS-associated C21ORF2 variant disrupts DNA damage repair, mitochondrial metabolism, neuronal excitability and NEK1 levels in human motor neurons.

Amyotrophic lateral sclerosis (ALS) is an adult-onset neurodegenerative disease leading to motor neuron loss. Currently mutations in > 40 genes have been linked to ALS, but the contribution of many genes and genetic mutations to the ALS pathogenic process remains poorly understood. Therefore, we first performed comparative interactome analyses of five recently discovered ALS-associated proteins (C21ORF2, KIF5A, NEK1, TBK1, and TUBA4A) which highlighted many novel binding partners, and both unique and shared interactors. The analysis further identified C21ORF2 as a strongly connected protein. The role of C21ORF2 in neurons and in the nervous system, and of ALS-associated C21ORF2 variants is largely unknown. Therefore, we combined human iPSC-derived motor neurons with other models and different molecular cell biological approaches to characterize the potential pathogenic effects of C21ORF2 mutations in ALS. First, our data show C21ORF2 expression in ALS-relevant mouse and human neurons, such as spinal and cortical motor neurons. Further, the prominent ALS-associated variant C21ORF2-V58L caused increased apoptosis in mouse neurons and movement defects in zebrafish embryos. iPSC-derived motor neurons from C21ORF2-V58L-ALS patients, but not isogenic controls, show increased apoptosis, and changes in DNA damage response, mitochondria and neuronal excitability. In addition, C21ORF2-V58L induced post-transcriptional downregulation of NEK1, an ALS-associated protein implicated in apoptosis and DDR. In all, our study defines the pathogenic molecular and cellular effects of ALS-associated C21ORF2 mutations and implicates impaired post-transcriptional regulation of NEK1 downstream of mutant C21ORF72 in ALS.

PAK1 inhibition with Romidepsin attenuates H-reflex hyperexcitability after spinal cord injury.

Hyperreflexia associated with spasticity is a prevalent neurological condition characterized by excessive and exaggerated reflex responses to stimuli. Hyperreflexia can be caused by several diseases including multiple sclerosis, stroke and spinal cord injury (SCI). Although we have previously identified the contribution of the RAC1-PAK1 pathway underlying spinal hyperreflexia with SCI-induced spasticity, a feasible druggable target has not been validated. To assess the utility of targeting PAK1 to attenuate H-reflex hyperexcitability, we administered Romidepsin, a clinically available PAK1 inhibitor, in Thy1-YFP reporter mice. We performed longitudinal EMG studies with a study design that allowed us to assess pathological H-reflex changes and drug intervention effects over time, before and after contusive SCI. As expected, our results show a significant loss of rate-dependent depression - an indication of hyperreflexia and spasticity - 1 month following SCI as compared with baseline, uninjured controls (or before injury). Romidepsin treatment reduced signs of hyperreflexia in comparison with control cohorts and in pre- and post-drug intervention in SCI animals. Neuroanatomical study further confirmed drug response, as romidepsin treatment also reduced the presence of SCI-induced dendritic spine dysgenesis on α-motor neurons. Taken together, our findings extend previous work demonstrating the utility of targeting PAK1 activity in SCI-induced spasticity and support the novel use of romidepsin as an effective tool for managing spasticity. KEY POINTS: PAK1 plays a role in contributing to the development of spinal cord injury (SCI)-induced spasticity by contributing to dendritic spine dysgenesis. In this study, we explored the preclinical utility of inhibiting PAK1 to reduce spasticity and dendritic spine dysgenesis in an SCI mouse model. Romidepsin is a PAK1 inhibitor approved in the US in 2009 for the treatment of cutaneous T-cell lymphoma. Here we show that romidepsin treatment after SCI reduced SCI-induced H-reflex hyperexcitability and abnormal α-motor neuron spine morphology. This study provides compelling evidence that romidepsin may be a promising therapeutic approach for attenuating SCI-induced spasticity.

Predictors of mortality post-gastrostomy in motor neuron disease patients.

INTRODUCTION/AIMS: Motor neuron disease (MND) is a progressive neurodegenerative condition with a limited life expectancy. There is very little data on mortality and its associated factors beyond 30 days following gastrostomy. We explored the demographic, clinical, and nutritional predictors for early mortality at 30, 90, and 180 days following gastrostomy in these patients. METHODS: This was a retrospective study involving 94 MND patients in Western Australia who underwent gastrostomy between 2015 and 2021. Patients were divided into two groups based on mortality at 30, 90, and 180 days post-gastrostomy. T-test (or Mann-Whitney), chi-square test and Fisher's exact test were used for detecting between-group differences in various factors. Multivariable logistic regression was used to identify factors associated with post-gastrostomy mortality at 90 and 180 days. RESULTS: No mortality was attributable to gastrostomy-related complications. Lower forced vital capacity (FVC) (p = .039) and greater weight loss (%) (p = .022) from diagnosis to gastrostomy were observed in those who died within 30 days post-gastrostomy. Older age (p = .022), male sex (p = .041), lower FVC (p = .04), requiring but not tolerating noninvasive ventilation (p = .035), and greater weight loss (%) (p = .012) were independent predictors of 90-day post-gastrostomy mortality. However, only older age (p = .01) and greater weight loss (p = .009) were predictors of mortality at 180 days post-gastrostomy. DISCUSSION: Our data indicated that mortality at 90 and 180 days was influenced by the weight loss (%) from diagnosis to gastrostomy, highlighting the importance of nutritional care in the MND population. Gastrostomy placement prior to substantial weight loss may reduce the risk of weight loss-associated mortality and warrants further investigation.

Poly-GP accumulation due to C9orf72 loss of function induces motor neuron apoptosis through autophagy and mitophagy defects.

The GGGGCC hexanucleotide repeat expansion (HRE) of the C9orf72 gene is the most frequent cause of amyotrophic lateral sclerosis (ALS), a devastative neurodegenerative disease characterized by motor neuron degeneration. C9orf72 HRE is associated with lowered levels of C9orf72 expression and its translation results in the production of dipeptide-repeats (DPRs). To recapitulate C9orf72-related ALS disease in vivo, we developed a zebrafish model where we expressed glycine-proline (GP) DPR in a c9orf72 knockdown context. We report that C9orf72 gain- and loss-of-function properties act synergistically to induce motor neuron degeneration and paralysis with poly(GP) accumulating preferentially within motor neurons along with Sqstm1/p62 aggregation indicating macroautophagy/autophagy deficits. Poly(GP) levels were shown to accumulate upon c9orf72 downregulation and were comparable to levels assessed in autopsy samples of patients carrying C9orf72 HRE. Chemical boosting of autophagy using rapamycin or apilimod, is able to rescue motor deficits. Proteomics analysis of zebrafish-purified motor neurons unravels mitochondria dysfunction confirmed through a comparative analysis of previously published C9orf72 iPSC-derived motor neurons. Consistently, 3D-reconstructions of motor neuron demonstrate that poly(GP) aggregates colocalize to mitochondria, thus inducing their elongation and swelling and the failure of their processing by mitophagy, with mitophagy activation through urolithin A preventing locomotor deficits. Finally, we report apoptotic-related increased amounts of cleaved Casp3 (caspase 3, apoptosis-related cysteine peptidase) and rescue of motor neuron degeneration by constitutive inhibition of Casp9 or treatment with decylubiquinone. Here we provide evidence of key pathogenic steps in C9ALS-FTD that can be targeted through pharmacological avenues, thus raising new therapeutic perspectives for ALS patients.