Spasticity and the use of intrathecal baclofen in patients with spinal cord injury

Low-dose Lipopolysaccharide Alleviates Spinal Cord Injury-induced Neuronal Inflammation by Inhibiting microRNA-429-mediated Suppression of PI3K/AKT/Nrf2 Signaling

This study investigated the impact of low-dose lipopolysaccharide (LPS) on spinal cord injury (SCI) and the potential molecular mechanism. Rats were randomly assigned to four groups: Sham, SCI, SCI + LPS, and SCI + LPS + agomir. Allen's weight-drop method was used to establish an in vivo SCI model. The Basso Bcattie Bresnahan rating scale was employed to monitor locomotor function. An in vitro SCI model was constructed by subjecting PC12 cells to oxygen and glucose deprivation/ reoxygenation (OGD/R). Enzyme-linked immunosorbent assay (ELISA) was applied for the determination interleukin (IL)-1β and IL-6. The dual luciferase reporter assay was used to validate the targeting of microRNA (miR)-429 with PI3K. Immunohistochemical staining was used to assess the expression of PI3K, phosphorylated AKT and Nrf2 proteins. The Nrf2-downstream anti-oxidative stress proteins, OH-1 and NQO1, were detected by western blot assay. MiR-429 expression was detected by fluorescence in situ hybridization and real-time quantitative reverse transcription PCR. In vitro, low-dose LPS decreased miR-429 expression, activated PI3K/AKT/Nrf2, inhibited oxidative stress and inflammation, and attenuated SCI. MiR-429 was found to target and negatively regulate PI3K. Inhibition of miR-429 suppressed low-dose LPS-mediated oxidative stress and inflammation via activation of the PI3K/AKT/Nrf2 pathway. In vivo, miR-429 was detectable in neurons. Inhibition of miR-429 blocked low-dose LPS-mediated oxidative stress and inflammation via activation of the PI3K/AKT/Nrf2 pathway. Overall, low-dose LPS was found to alleviate SCI-induced neuronal oxidative stress and inflammatory response by down-regulating miR-429 to activate the PI3K/AKT/Nrf2 pathway.

Diaphragm pacing implantation in Japan for a patient with cervical spinal cord injury: A case report

RATIONALE

Traumatic cervical spinal cord injury (SCI) is a devastating condition leading to respiratory failure that requires permanent mechanical ventilation, which is the main driver of increased medical costs. There is a great demand for establishing therapeutic interventions to treat respiratory dysfunction following severe cervical SCI.

PATIENT CONCERNS AND DIAGNOSIS

We present a 24-year-old man who sustained a cervical displaced C2-C3 fracture with SCI due to a traffic accident. As the patient presented with tetraplegia and difficulty in spontaneous breathing following injury, he was immediately intubated and placed on a ventilator with cervical external fixation by halo orthosis. The patient then underwent open reduction and posterior fusion of the cervical spine 3 weeks after injury. Although the patient showed significant motor recovery of the upper and lower limbs over time, only a slight improvement in lung capacity was observed.

INTERVENTIONS AND OUTCOMES

At 1.5 years after injury, a diaphragmatic pacing stimulator was surgically implanted to support the patient's respiratory function. The mechanical ventilator support was successfully withdrawn from the patient 14 weeks after implantation. We observed that both the vital capacity and tidal volume of the patient were significantly promoted following implantation. The patient finally returned to daily life without any mechanical support.

LESSONS

The findings of this report suggest that diaphragmatic pacing implantation could be a promising treatment for improving respiratory function after severe cervical SCI. To our knowledge, this is the first SCI patient treated with a diaphragm pacing implantation covered by official medical insurance in Japan.

Evaluating the use of baclofen as adjunct treatment for muscle tension dysphonia

OBJECTIVE

To explore whether use of baclofen as adjunct treatment to voice therapy (VT) led to improvement in subjective throat symptoms in patients with primary muscle tension dysphonia (MTD). MTD is associated with excessive paralaryngeal muscle contraction, and baclofen is a muscle relaxant.

STUDY DESIGN

Cross-sectional, questionnaire-based study.

METHODS

An initial pool of patients, who were diagnosed with primary MTD and received 1+ VT session(s) at a single tertiary-care center from 2015 to 2019, were placed into either a baclofen group (prescribed 10 mg baclofen t.i.d. PRN along with VT) based on symptomatology or non-baclofen group (VT alone). They were administered questionnaires via postage mail or phone that included the Voice Handicap Index-10 (VHI-10), Reflux Symptom Index (RSI), and other survey elements. A retrospective chart review collected demographic and other clinical data from recruited participants.

RESULTS

A total of 314 non-baclofen and 63 baclofen patients met the inclusion criteria of this study, with 37 non-baclofen patients (mean age = 47.5 years, 62.2% female) and 15 baclofen patients (mean age = 45.5 years, 73.3% female) recruited. There was no significant difference in mean [SD] VHI-10 scores (11.30 [8.20] vs. 12.60 [10.75]; p = 0.638) and RSI scores (13.46 [10.44] vs. 16.20 [10.65]; p = 0.398) between non-baclofen and baclofen groups, respectively.

CONCLUSION

There was no significant difference in voice psychometric outcomes between non-baclofen and baclofen groups, measured primarily by the VHI-10 and RSI questionnaire components. Further studies are warranted to assess the efficacy and safety of baclofen as a therapeutic option for MTD.

Knockdown of SNHG1 alleviates autophagy and apoptosis by regulating miR-362-3p/Jak2/stat3 pathway in LPS-injured PC12 cells

Spinal cord injury (SCI) is a serious neurological disease. Long non-coding RNA (lncRNA) small nucleolar RNA host gene (SNHG1) and microRNA-362-3p (miR-362-3p) were confirmed to be related to neurological disorders. However, it is unclear whether SNHG1 was involved in the development of SCI via regulating miR-362-3p. PC12 cells were treated with lipopolysaccharide (LPS) to imitate the in vitro cell model of SCI. Cell ciability and apoptosis rate were detected by cell counting kit-8 (CCK-8) assay and flow cytometry assay. The levels of SNHG1, miR-362-3p, and Janus kinase-2 (Jak2) were examined by quantitative real-time polymerase chain reaction (qRT-PCR). The dual-luciferase reporter assay, RNA pull-down assay, and RNA immunoprecipitation (RIP) assay were performed to verify the interaction between miR-362-3p and SNHG1 or Jak2. Besides, the levels of apoptosis- and autophagy- related proteins were detected by western blot assay. In present research, LPS suppressed cell viability, and induced apoptosis and autophagy in PC12 cells. SNHG1 knockdown could affect cell viability, and suppress cell apoptosis and autophagy in LPS-treated PC12 cells. Moreover, miR-362-3p was a target of SNHG1, miR-362-3p targeted Jak2 and negatively regulated Jak2/stat3 pathway. Our data also demonstrated that SNHG1 depletion inactivated Jak2/stat3 pathway to affect cell viability and confine apoptosis, autophagy in LPS-treated PC12 cells. Taken together, SNHG1 regulated cell viability, apoptosis and autophagy in LPS-treated PC12 cells by activating Jak2/stat3 pathway via sponging miR-362-3p.

Classics in Chemical Neuroscience: Baclofen

Baclofen, β-(4-chlorophenyl)-γ-aminobutyric acid, holds a unique position in neuroscience, remaining the only U.S. Food and Drug Administration (FDA) approved GABA_B agonist. While intended to be a more brain penetrant, i.e, ability to cross the blood-brain barrier (BBB), version of GABA (γ-aminobutyric acid) for the potential treatment of epilepsy, baclofen's highly efficacious muscle relaxant properties led to its approval, as a racemate, for the treatment of spasticity. Interestingly, baclofen received FDA approval before its receptor, GABA_B, was discovered and its exact mechanism of action was known. In recent times, baclofen has a myriad of off-label uses, with the treatment for alcohol abuse and drug addiction garnering a great deal of attention. This Review aims to capture the >60 year legacy of baclofen by walking through the history, pharmacology, synthesis, drug metabolism, routes of administration, and societal impact of this Classic in chemical neuroscience.

Immunosuppressive mechanisms for stem cell transplant survival in spinal cord injury

Spinal cord injury (SCI) has been associated with a dismal prognosis-recovery is not expected, and the most standard interventions have been temporizing measures that do little to mitigate the extent of damage. While advances in surgical and medical techniques have certainly improved this outlook, limitations in functional recovery continue to impede clinically significant improvements. These limitations are dependent on evolving immunological mechanisms that shape the cellular environment at the site of SCI. In this review, we examine these mechanisms, identify relevant cellular components, and discuss emerging treatments in stem cell grafts and adjuvant immunosuppressants that target these pathways. As the field advances, we expect that stem cell grafts and these adjuvant treatments will significantly shift therapeutic approaches to acute SCI with the potential for more promising outcomes.

The Biology of Regeneration Failure and Success After Spinal Cord Injury

Since no approved therapies to restore mobility and sensation following spinal cord injury (SCI) currently exist, a better understanding of the cellular and molecular mechanisms following SCI that compromise regeneration or neuroplasticity is needed to develop new strategies to promote axonal regrowth and restore function. Physical trauma to the spinal cord results in vascular disruption that, in turn, causes blood-spinal cord barrier rupture leading to hemorrhage and ischemia, followed by rampant local cell death. As subsequent edema and inflammation occur, neuronal and glial necrosis and apoptosis spread well beyond the initial site of impact, ultimately resolving into a cavity surrounded by glial/fibrotic scarring. The glial scar, which stabilizes the spread of secondary injury, also acts as a chronic, physical, and chemo-entrapping barrier that prevents axonal regeneration. Understanding the formative events in glial scarring helps guide strategies towards the development of potential therapies to enhance axon regeneration and functional recovery at both acute and chronic stages following SCI. This review will also discuss the perineuronal net and how chondroitin sulfate proteoglycans (CSPGs) deposited in both the glial scar and net impede axonal outgrowth at the level of the growth cone. We will end the review with a summary of current CSPG-targeting strategies that help to foster axonal regeneration, neuroplasticity/sprouting, and functional recovery following SCI.

Dorsal Longitudinal T-Myelotomy (Bischof II Technique): A Useful, Antiquated Procedure for the Treatment of Intractable Spastic Paraplegia

OBJECTIVE

Dorsal longitudinal T-myelotomy is a long-established operation to treat severe spastic paraplegia. The present study aimed to report this surgical technique and investigate the efficacy of T-myelotomy for spasticity relief.

METHODS

All cases undergoing T-myelotomy for treatment of intractable spastic paraplegia during 2009-2017 were included. The severity of spasticity was evaluated with the Modified Ashworth Scale, Penn Spasm Frequency Scale, Adductor Tone Rating Scale, degree of passive range of motion, and occurrence of abdominal muscle spasms. Other clinical assessments included deep tendon reflex assessed by the National Institute of Neurological Disorders and Stroke scale, Babinski sign, healing of decubitus ulcers, and ambulatory status.

RESULTS

Fourteen patients with a mean age of 39.3 ± 13.4 years were included. The 7 patients with abdominal muscle spasms before surgery had no spasms after surgery. The Babinski sign was absent in all cases after surgery. Unhealed pressure ulcers in all 9 cases were healed after surgery. All 4 patients with a preoperative bed-bound condition were able to ambulate with a wheelchair. A statistically significant improvement in mean Modified Ashworth Scale score, degree of passive range of motion, and National Institute of Neurological Disorders and Stroke scale score was found in the subgroup and overall analyses. There was also a statistically significant improvement in the Penn Spasm Frequency Scale and Adductor Tone Rating Scale scores.

CONCLUSIONS

Dorsal longitudinal T-myelotomy remains an effective option for the treatment of intractable spastic paraplegia. It is suitable for, and may be an alternative to, intrathecal baclofen therapy for patients with complete spinal cord lesion or patients without hope of regaining motor function.

Mechanical Stress by Spasticity Accelerates Fracture Healing After Spinal Cord Injury

Accelerated fracture healing in patients with spinal cord injuries (SCI) is often encountered in clinical practice. However, there is no distinct evidence in the accelerated fracture healing, and the mechanisms of accelerated fracture healing in SCI are poorly understood. We aimed to determine whether SCI accelerated fracture healing in morphology and strength, to characterize the healing process with SCI, and to clarify the factors responsible for accelerated fracture healing. In total, 39 male Wistar rats were randomly divided into healthy control without intervention, SCI only, fracture with SCI, botulinum toxin (BTX) A-treated fracture with SCI, and propranolol-treated fracture with SCI groups. These rats were assessed with computed microtomography, histological, histomorphological, immunohistological, and biomechanical analyses. Both computed microtomography and histological analyses revealed the acceleration of a bony union in animals with SCI. The strength of the healed fractures after SCI recovered to the same level as that of intact bones after SCI, while the healed bones were weaker than the intact bones. Immunohistology revealed that SCI fracture healing was characterized by formation of callus with predominant intramembranous ossification and promoting endochondral ossification. The accelerated fracture healing after SCI was attenuated by BTX injection, but did not change by propranolol. We demonstrated that SCI accelerate fracture healing in both morphology and strength. The accelerated fracture healing with SCI may be due to predominant intramembranous ossification and promoting endochondral ossification. In addition, our results also suggest that muscle contraction by spasticity accelerates fracture healing after SCI.

Outcomes of intrathecal baclofen therapy in patients with cerebral palsy and acquired brain injury

Intrathecal baclofen (ITB) has been known to reduce spasticity which did not respond to oral medications and botulinum toxin treatment. However, few results have been reported comparing the effects of ITB therapy in patients with cerebral palsy (CP) and acquired brain injury. This study aimed to investigate beneficial and adverse effects of ITB bolus injection and pump therapy in patients with CP and to compare outcomes to patients with acquired brain injury such as traumatic brain injury and hypoxic brain injury. ITB test trials were performed in 37 patients (19 CP and 18 acquired brain injury). Based on ambulatory function, CP patients were divided into 2 groups: 11 patients with nonambulatory CP and 8 patients with ambulatory CP. Change of spasticity was evaluated using the Modified Ashworth Scale. Additional positive or negative effects were also evaluated after ITB bolus injection. In patients who received ITB pump implantation, outcomes of spasticity, subjective satisfaction and adverse events were evaluated until 12 months post-treatment. After ITB bolus injection, 32 patients (86.5%) (CP 84.2% versus acquired brain injury 88.9%) showed a positive response of reducing spasticity. However, 8 patients with CP had negative adverse effects. Particularly, 3 ambulatory CP patients showed standing impairment and 1 ambulatory CP patient showed impaired gait pattern such as foot drop because of excessive reduction of lower extremity muscle tone. Ambulatory CP patients received ITB pump implantation less than patients with acquired brain injury after ITB test trials (P = .003 by a chi-squared test). After the pump implantation, spasticity was significantly reduced within 1 month and the effect maintained for 12 months. Seventeen patients or their caregivers (73.9%) were very satisfied, whereas 5 patients (21.7%) suffered from adverse events showed no subjective satisfaction. In conclusion, ITB therapy was effective in reducing spasticity in patients with CP and acquired brain injury. Before ITB pump implantation, it seems necessary to perform the ITB bolus injection to verify beneficial effects and adverse effects especially in ambulatory CP.