Skin and not dorsal root stimulation reduces hypertonus in thoracic motor complete spinal cord injury: a single case report.

On demand and localized treatment for excessive muscle tone after spinal cord injury (SCI) is currently not available. Here, we examine the reduction in leg hypertonus in a person with mid-thoracic, motor complete SCI using a commercial transcutaneous electrical stimulator (TES) applied at 50 or 150 Hz to the lower back and the possible mechanisms producing this bilateral reduction in leg tone. Hypertonus of knee extensors without and during TES, with both cathode (T11-L2) and anode (L3-L5) placed over the spinal column (midline, MID) or 10 cm to the left of midline (lateral, LAT) to only active underlying skin and muscle afferents, was simultaneously measured in both legs with the pendulum test. Spinal reflexes mediated by proprioceptive (H-reflex) and cutaneomuscular reflex (CMR) afferents were examined in the right leg opposite to the applied LAT TES. Hypertonus disappeared in both legs but only during thoracolumbar TES, and even during LAT TES. The marked reduction in tone was reflected in the greater distance both lower legs first dropped to after being released from a fully extended position, increasing by 172.8% and 94.2% during MID and LAT TES, respectively, compared with without TES. Both MID and LAT (left) TES increased H-reflexes but decreased the first burst, and lengthened the onset of subsequent bursts, in the cutaneomuscular reflex of the right leg. Thoracolumbar TES is a promising method to decrease leg hypertonus in chronic, motor complete SCI without activating spinal cord structures and may work by facilitating proprioceptive inputs that activate excitatory interneurons with bilateral projections that in turn recruit recurrent inhibitory neurons.NEW & NOTEWORTHY We present proof of concept that surface stimulation of the lower back can reduce severe leg hypertonus in a participant with motor complete, thoracic spinal cord injury (SCI) but only during the applied stimulation. We propose that activation of skin and muscle afferents from thoracolumbar transcutaneous electrical stimulation (TES) may recruit excitatory spinal interneurons with bilateral projections that in turn recruit recurrent inhibitory networks to provide on demand suppression of ongoing involuntary motoneuron activity.

Cervicothoracic ventral-dorsal rhizotomy for treatment of brachial hypertonia in cerebral palsy.

PURPOSE: Cervicothoracic ventral-dorsal rhizotomy (VDR) is a potential treatment of medically refractory hypertonia in patients who are not candidates for intrathecal baclofen, particularly in cases of severe upper limb hypertonia with limited to no function. A longitudinal cohort was identified to highlight our institutional safety and efficacy using cervicothoracic VDR for the treatment of hypertonia. METHODS: Retrospective data analysis was performed for patients that underwent non-selective cervicothoracic VDR between 2022 and 2023. Non-modifiable risk factors, clinical variables, and operative characteristics were collected. RESULTS: Six patients (three female) were included. Four patients underwent a bilateral C6-T1 VDR, one patient underwent a left C7-T1 VDR, and another underwent a left C6-T1 VDR. Three patients had quadriplegic mixed hypertonia, one patient had quadriplegic spasticity, one patient had triplegic mixed hypertonia, and one patient had mixed hemiplegic hypertonia. The mean difference of proximal upper extremity modified Ashworth scale (mAS) was - 1.4 ± 0.55 (p = 0.002), and - 2.2 ± 0.45 (p < 0.001) for the distal upper extremity. Both patients with independence noted quality of life improvements as well as increased ease with dressing and orthotics fits. Caregivers for the remaining four patients noted improvements in caregiving provision, mainly in dressing, orthotics fit, and ease when transferring. CONCLUSION: Cervicothoracic VDR is safe and provides tone control and quality of life improvements in short-term follow-up. It can be considered for the treatment of refractory hypertonia. Larger multicenter studies with longer follow-up are necessary to further determine safety along with long-term functional benefits in these patients.

The effect of suboccipital muscle dysfunction on the biomechanics of the upper cervical spine: a study based on finite element analysis.

OBJECTIVE: Muscle dysfunction caused by repetitive work or strain in the neck region can interfere muscle responses. Muscle dysfunction can be an important factor in causing cervical spondylosis. However, there has been no research on how the biomechanical properties of the upper cervical spine change when the suboccipital muscle group experiences dysfunction. The objective of this study was to investigate the biomechanical evidence for cervical spondylosis by utilizing the finite element (FE) approach, thus and to provide guidance for clinicians performing acupoint therapy. METHODS: By varying the elastic modulus of the suboccipital muscle, the four FE models of C0-C3 motion segments were reconstructed under the conditions of normal muscle function and muscle dysfunction. For the two normal condition FE models, the elastic modulus for suboccipital muscles on both sides of the C0-C3 motion segments was equal and within the normal range In one muscle dysfunction FE model, the elastic modulus on both sides was equal and greater than 37 kPa, which represented muscle hypertonia; in the other, the elastic modulus of the left and right suboccipital muscles was different, indicating muscle imbalance. The biomechanical behavior of the lateral atlantoaxial joint (LAAJ), atlanto-odontoid joint (ADJ), and intervertebral disc (IVD) was analyzed by simulations, which were carried out under the six loadings of flexion, extension, left and right lateral bending, left and right axial rotation. RESULTS: Under flexion, the maximum stress in LAAJ with muscle imbalance was higher than that with normal muscle and hypertonia, while the maximum stress in IVD in the hypertonic model was higher than that in the normal and imbalance models. The maximum stress in ADJ was the largest under extension among all loadings for all models. Muscle imbalance and hypertonia did not cause overstress and stress distribution abnormalities in ADJ. CONCLUSION: Muscle dysfunction increases the stress in LAAJ and in IVD, but it does not affect ADJ.

Nonselective lumbosacral ventral-dorsal rhizotomy for the management of lower-limb hypertonia in nonambulatory children with cerebral palsy.

OBJECTIVE: Children with cerebral palsy (CP) often experience medically refractory hypertonia, for which there are surgical therapies including neuromodulation and rhizotomy. Traditional surgical treatment for medically refractory mixed hypertonia or dystonia includes intrathecal baclofen pumps and selective dorsal rhizotomy. A nonselective lumbosacral ventral-dorsal rhizotomy (VDR; ventral and dorsal roots lesioned by 80%-90%) has the potential to address the limitations of traditional surgical options. The authors highlighted the institutional safety and efficacy of nonselective lumbosacral VDR for palliative tone management in nonambulatory patients with more severe CP. METHODS: The authors performed a retrospective analysis of patients who had undergone lumbosacral VDR between 2022 and 2023. Demographic factors, clinical variables, and operative characteristics were collected. The primary outcomes of interest included tone control and quality of life improvement. Secondary outcome measures included, as a measure of safety, perioperative events such as paresthesias. Postoperative complications were also noted. RESULTS: Fourteen patients (7 female) were included in the study. All patients had undergone a T12-L2 osteoplastic laminoplasty and bilateral L1-S1 VDR. Nine patients had quadriplegic mixed hypertonia, 4 had quadriplegic spasticity, and 1 had generalized secondary dystonia. Following VDR, there was a significant decrease in both lower-extremity modified Ashworth Scale (mAS) scores (mean difference [MD] -2.77 ± 1.0, p < 0.001) and upper-extremity mAS scores (MD -0.71 ± 0.76, p = 0.02), with an average follow-up of 3 months. In the patient with generalized dystonia, the lower-extremity Barry-Albright Dystonia Scale score decreased from 8 to 0, and the overall score decreased from 32 to 13. All parents noted increased ease in caregiving, particularly in terms of positioning, transfers, and changing. The mean daily enteral baclofen dose decreased from 47 mg preoperatively to 24.5 mg postoperatively (p < 0.001). Three patients developed wound dehiscence, 2 of whom had concurrent infections. CONCLUSIONS: Lumbosacral VDR is safe, is effective for tone control, and can provide quality of life improvements in patients with medically refractory lower-limb mixed hypertonia. Lumbosacral VDR can be considered for palliative tone control in nonambulatory patients with more severe CP. Larger studies with longer follow-ups are necessary to further determine safety and long-term benefits in these patients.

Safety and efficacy of continuous intrathecal baclofen via cervical catheter tip: a retrospective case series.

OBJECTIVE: Intrathecal baclofen (ITB) is an effective treatment for hypertonia in children involving the implantation of a pump and catheter system. The highest concentration of ITB is at the catheter tip. The catheter tip location is most commonly within the lumbar or thoracic spine. The cervical tip location has traditionally been avoided because of concerns of hypoventilation and pneumonia; however, these complications in cervical compared with thoracic or lumbar placement have not been reliably proven. Some studies have suggested that cervical ITB location better treats upper-extremity hypertonia. There are limited data describing the safety and efficacy of cervical ITB on hypertonia. The authors present a single-institution retrospective case series highlighting the safety and efficacy of using cervical ITB location for the treatment of hypertonia. METHODS: Retrospective data analysis was performed for children who underwent continuous dosing cervical ITB between April 2022 and October 2023. Nonmodifiable risk factors, clinical variables, operative characteristics, and adverse outcomes were collected. RESULTS: This study included 25 patients (8 female). The mean age at implantation was 12.4 years, and the mean operative duration was 90 minutes. The mean Barry-Albright Dystonia Scale score decreased by 9.5 points (p = 0.01). The mean aggregated modified Ashworth scale score in the upper extremities decreased by 2.14 points (p = 0.04), and that in the lower extremities decreased by 4.98 points (p < 0.01). One patient each (4%) had infection and baclofen toxicity. Two patients (8%) had respiratory depression requiring continuous positive airway pressure. There was no incidence of pneumonia or wound dehiscence. CONCLUSIONS: The cervical catheter tip location for ITB is safe, is effective to control tone, and should be considered for the treatment of hypertonia. Larger studies with longer follow-up are necessary to further determine upper-limit dosing safety along with long-term functional benefits in these patients.

Tone management: An environmental scan of current management practices across Canada.

BACKGROUND: Currently, there are no standardized approaches to care or evaluation for tone dysfunction in Canada. The study authors hypothesize that there is significant practice variation across the country. This environmental scan is aimed to describe the current practice for management of paediatric patients with hypertonia across Canada. METHODS: A web-based survey was developed by the authors with a multi-disciplinary approach and sent to representative paediatric rehabilitation sites in each province in Canada. Disciplines at the rehabilitation sites surveyed included all or some of the following disciplines: physiatry, neurology, neurosurgery, plastic surgery, orthopaedic surgery, physiotherapy and occupational therapy. All statistical analyses were performed using the R statistical software version 4.0. Fifteen rehabilitation sites were contacted, and 12 sites were used for the final analysis. RESULTS: Cerebral palsy was found to be the most common diagnosis for tone dysfunction, with 58% of sites diagnosing greater than 20 new patients per year. In 67% of sites, patients were seen within a formal multidisciplinary clinic to manage hypertonia. All 12 sites utilized oral baclofen and gabapentin, and 92% of sites utilized trihexyphenidyl. Botulinum toxin injections were offered at 50% of sites. Upper and lower extremity surgical procedures were offered in 83% of the sites. CONCLUSION: The information gained from this study provides some insight into the current practice across Canada for children with hypertonia. This study may assist in the development of a national, standardized strategy to tone management, potentially facilitating more equitable access to care for patients.

A novel biallelic frameshift variant in C2orf69 causing developmental regression, seizures, microcephaly, autistic features, and hypertonia.

Combined oxidative phosphorylation deficiency type 53 (COXPD53) is an autosomal recessive neurodevelopmental disorder (NDD) caused by homozygous variants in the gene C2orf69. Here, we report a novel frameshift variant c.187_191dupGCCGA, p.D64Efs*56 identified in an individual with clinical presentation of COXPD53 with developmental regression and autistic features. The variant c.187_191dupGCCGA, p.D64Efs*56 represents the most N-terminal part of C2orf69. Notable clinical features of COXPD53of the proband include developmental delay, developmental regression, seizures, microcephaly, and hypertonia. Structural brain defects of cerebral atrophy, cerebellar atrophy, hypomyelination, and thin corpus callosum were also observed. While we observe strong phenotypic overlap among affected individuals with C2orf69 variants, developmental regression and autistic features have not been previously described in individuals with COXPD53. Together, this case expands the genetic and clinical phenotypic spectrum of C2orf69-associated COXPD53.

Spastic dystonia: Still a valid term.

Hypertonia in childhood may arise because of a variable combination of neuronal and non-neuronal factors. Involuntary muscle contraction may be due to spasticity or dystonia, which represent disorders of the spinal reflex arch and of central motor output respectively. Whilst consensus definitions for dystonia have been established, definitions of spasticity vary, highlighting the lack of a single unifying nomenclature in the field of clinical movement science. The term spastic dystonia refers to involuntary tonic muscle contraction in the context of an upper motor neuron (UMN) lesion. This review considers the utility of the term spastic dystonia, exploring our understanding of the pathophysiology of dystonia and the UMN syndrome. An argument is advanced that spastic dystonia is a valid construct that warrants further exploration. WHAT THIS PAPER ADDS: There is no single universally accepted definitions for terms commonly used to describe motor disorders. Spasticity and dystonia are phenomenologically and pathophysiologically distinct entities. Spastic dystonia represents a subset of dystonia, but with pathophysiological mechanisms more in common with spasticity.

Transcriptome and Small RNA Sequencing Reveals the Basis of Response to Salinity, Alkalinity and Hypertonia in Quinoa (Chenopodium quinoa Willd.).

Quinoa (Chenopodium quinoa Willd.) is a dicotyledonous cereal that is rich in nutrients. This important crop has been shown to have significant tolerance to abiotic stresses such as salinization and drought. Understanding the underlying mechanism of stress response in quinoa would be a significant advantage for breeding crops with stress tolerance. Here, we treated the low-altitude quinoa cultivar CM499 with either NaCl (200 mM), Na2CO3/NaHCO3 (100 mM, pH 9.0) or PEG6000 (10%) to induce salinity, alkalinity and hypertonia, respectively, and analyzed the subsequent expression of genes and small RNAs via high-throughput sequencing. A list of known/novel genes were identified in quinoa, and the ones responding to different stresses were selected. The known/novel quinoa miRNAs were also identified, and the target genes of the stress response ones were predicted. Both the differently expressed genes and the targets of differently expressed miRNAs were found to be enriched for reactive oxygen species homeostasis, hormone signaling, cell wall synthesis, transcription factors and some other factors. Furthermore, we detected changes in reactive oxygen species accumulation, hormone (auxin and ethylene) responses and hemicellulose synthesis in quinoa seedlings treated with stresses, indicating their important roles in the response to saline, alkaline or hyperosmotic stresses in quinoa. Thus, our work provides useful information for understanding the mechanism of abiotic stress responses in quinoa, which would provide clues for improving breeding for quinoa and other crops.

A case of complex hemangioendothelioma of the liver in an infant.

A physical examination of a 9-month-old female infant presenting with vomiting and diarrhea revealed tenderness in the right upper abdomen and heightened abdominal muscle tone. Abdominal ultrasonography identified an irregular hypoechoic area within the right lobe of the liver. While a subsequent enhanced CT examination disclosed a well-defined lesion exhibiting internal focal calcification and delayed heterogeneous enhancement. Subsequently, she underwent surgical resection, and postoperative pathology revealed areas of epithelioid hemangioendothelioma and cavernous hemangioma. Immunohistochemistry demonstrated positive expression of CD34, CD31, FLI-1, and F-VIII. The pathologic diagnosis was confirmed as composite hemangioendothelioma (CHE).

[Sacral neuromodulation for bladder voiding dysfunction: Experience at a French university center]. / Neuromodulation sacrée pour trouble de la vidange vésicale : expérience d'un centre universitaire français.

OBJECTIVE: To report the experience of a university hospital center with sacral neuromodulation for patients with bladder voiding disorders. MATERIAL AND METHODS: All patients who underwent sacral neuromodulation between 1998 and 2022 for bladder voiding disorders were included. Medical records were analyzed retrospectively, and population, efficacy and follow-up data were collected. RESULTS: A total of 134 patients underwent test implantation and 122 patients were analyzed. 68 patients (56%) were implanted with a definitive neuromodulation device. Mean age was 43±16 years and BMI 25.5±5.4kg/m2. 74% were women. Bladder voiding disorder was due to sphincter hypertonia in 51% of cases, with associated bladder hypocontractility in 29%. The spontaneous micturition rate after implantation increased from 34% to 92%. Implantation results appeared to be better in patients with sphincter hypertonia, whether or not associated with bladder hypocontractility. The benefit was most often present with a frequency of 5Hz (54.4%). Side-effects were present in 52% of cases at 5 years, and in 85% of cases were pain in relation to the implanted devices. They resolved under medical treatment or after revision of the device (27% of cases at 5 years). CONCLUSION: SNM is effective in micturition recovery, but has side effects. Urodynamic mechanism and etiology may provide clues for modulating NMS box settings and determining predictive factors for NMS success. Data from other centers are needed to identify reliable predictive factors.

Effects of Pharmacologic Treatment for Neonatal Abstinence Syndrome on DNA Methylation and Neurobehavior: A Prospective Cohort Study.

OBJECTIVE: To determine whether pharmacologic treatment for neonatal abstinence syndrome (NAS) is associated with changes in DNA methylation (DNAm) of the mu-opioid receptor gene (OPRM1) and improvements in neonatal neurobehavior. STUDY DESIGN: Buccal swabs were collected from 37 neonates before and after morphine treatment for NAS. Genomic DNA was extracted, and DNAm was examined at 4 cytosine-phosphate-guanine (CpG) sites within the OPRM1 gene. Assessment with the NICU Network Neurobehavioral Scales (NNNS) was also performed before and after NAS treatment. Changes in DNAm (DNAmpost-tx - DNAmpre-tx) and NNNS summary scores (NNNSpost-tx - NNNSpre-tx) were then calculated. Path analysis was used to examine associations among pharmacologic treatment (length of treatment [LOT] and total dose of morphine), changes in DNAm, and changes in NNNS summary scores. RESULTS: DNAm was significantly decreased from pretreatment to post-treatment at 1 of 4 CpG sites within the OPRM1 gene. Neonates also demonstrated decreased excitability, hypertonia, lethargy, signs of stress and abstinence, and increased quality of movement and regulation from pretreatment to post-treatment. Longer LOT and higher morphine dose were associated with greater decreases in DNAm; greater decreases in DNAm were associated with greater decreases in excitability and hypertonia on the NNNS. CONCLUSIONS: Pharmacologic treatment of NAS is associated with decreased DNAm of the OPRM1 gene and improved neonatal neurobehavior. Epigenetic changes may play a role in these changes in neonatal neurobehavior.

Lasting Peripheral and Central Effects of Botulinum Toxin Type A on Experimental Muscle Hypertonia in Rats.

Recent animal experiments suggested that centrally transported botulinum toxin type A (BoNT-A) might reduce an abnormal muscle tone, though with an unknown contribution to the dominant peripheral muscular effect observed clinically. Herein, we examined if late BoNT-A antispastic actions persist due to possible central toxin actions in rats. The early effect of intramuscular (i.m.) BoNT-A (5, 2 and 1 U/kg) on a reversible tetanus toxin (TeNT)-induced calf muscle spasm was examined 7 d post-TeNT and later during recovery from flaccid paralysis (TeNT reinjected on day 49 post-BoNT-A). Lumbar intrathecal (i.t.) BoNT-A-neutralizing antiserum was used to discriminate the transcytosis-dependent central toxin action of 5 U/kg BoNT-A. BoNT-A-truncated synaptosomal-associated protein 25 immunoreactivity was examined in the muscles and spinal cord at day 71 post-BoNT-A. All doses (5, 2 and 1 U/kg) induced similar antispastic actions in the early period (days 1-14) post-BoNT-A. After repeated TeNT, only the higher two doses prevented the muscle spasm and associated locomotor deficit. Central trans-synaptic activity contributed to the late antispastic effect of 5 U/kg BoNT-A. Ongoing BoNT-A enzymatic activity was present in both injected muscle and the spinal cord. These observations suggest that the treatment duration in sustained or intermittent muscular hyperactivity might be maintained by higher doses and combined peripheral and central BoNT-A action.

[Pilot study: evaluation of manual methods for modulating the cardinal symptom tinnitus : A prospective randomized study]. / Pilotstudie: manualmedizinische Methodenevaluation zur Modulierbarkeit des Leitsymptoms Tinnitus : Eine prospektive randomisierte Studie.

BACKGROUND: Tinnitus and vertigo have been studied in many ways. This led to a variety of explanations from multiple medical disciplines. The musculature of the jaw and cervical spine have also been researched in this regard. Dysfunctional musculature can trigger tinnitus and dizziness. This subtype of tinnitus is called cervicogenic somatosensory tinnitus. OBJECTIVE: The aim of the present study was to investigate the effect of manual therapy on subject-reported, individually perceived impairment due to cervicogenic somatosensory tinnitus (Tinnitus Handicap Inventory), dizziness (Dizziness Handicap Inventory), and hypertonia of the musculature of the head and cervical spine. MATERIALS AND METHODS: In a prospective randomized trial, 80 patients (40 in the intervention group/40 in the control group) were medically examined and interviewed. Afterwards, they received targeted manual therapy. RESULTS: After manual therapy, there were significant differences in the Tinnitus Handicap Inventory, Dizziness Handicap Inventory, and muscular hypertonia between the groups, all in favor of the intervention group. CONCLUSION: Manual examination and therapy proved to be effective. It should be increasingly applied in the absence of ENT pathology and suspected cervicogenic somatosensory tinnitus. The role of individual muscles requires further investigation.

[How to treat spasticity after stroke ?] / Comment je traite la spasticité après un accident vasculaire cérébral.

Spasticity is a form of hypertonia frequently encountered in patients who suffered from stroke and is a cause of functional limitation, contractures, osteoarticular deformations, pain and wounds. The first-line treatment of focal or multifocal spasticity consists in intramuscular injections of botulinum toxin type A in the muscles concerned, in association with positioning measures and physical therapy. Despite the fact this pathology is common, there is often a delay in the diagnosis, and consequently the treatment, leading to harmful consequences for the patient. In some specific indications, surgery can also be a therapeutic option. Finally, spasticity should be distinguished from other types of hypertonia, e.g. dystonia.

: La spasticité est une forme d'hypertonie, fréquemment rencontrée dans les suites d'un accident vasculaire cérébral. Elle peut être à l'origine de limitations fonctionnelles, de rétractions tendineuses, de déformations ostéoarticulaires, de douleurs et de plaies. Le traitement de première ligne de la spasticité focale ou multifocale repose sur l'injection intramusculaire de toxine botulique de type A dans les muscles entrepris, en association à des mesures de positionnement et à une prise en charge kinésithérapeutique. Malgré la fréquence de cette affection, elle est encore trop souvent reconnue, et donc traitée, tardivement, ce qui aboutit à des conséquences délétères pour le patient. Dans certaines indications précises, la chirurgie a également une place dans l'arsenal thérapeutique de la spasticité. Enfin, la spasticité ne doit pas être confondue avec les autres formes d'hypertonie, comme la dystonie.

Partial Division of Puborectalis Muscle with Lateral Internal Sphincterotomy: A Novel Surgical Technique for Management of Anal Hypertonia-Associated Anismus.

BACKGROUND: Treatment of anismus usually starts with biofeedback therapy and injection of botulinum toxin in the puborectalis muscle (PRM). Patients refractory to conservative treatment may require surgery. The present cohort study aimed to assess a combined technique of partial division of PRM and tailored lateral internal sphincterotomy (LIS) in treatment of anismus. METHODS: Patients with anismus who failed conservative treatments were assessed clinically and with high-resolution anal manometry (HRAM), EMG, defecography, and underwent combined partial division of PRM on one side and tailored LIS on the contralateral side. Main outcome measures were improvement in symptoms and quality of life, changes in HRAM and defecography postoperatively, complications, and patient satisfaction. RESULTS: A total of 73 patients (61 male) of a mean age of 37 years were included to the study. In total, 89% of patients showed a significant improvement in symptoms at 12 months postoperatively. The mean modified Altomare score decreased significantly (p < 0.0001) from 16.4 ± 1.7 to 6.6 ± 1 at 12 months postoperatively. There was a significant increase in the mental and physical components of quality of life at 12 months postoperatively. The numbers of patients with positive findings of anismus in postoperative defecography, EMG, and balloon expulsion test were significantly less than before surgery. The mean total satisfaction score was 86.5 ± 8.7. Five (6.5%) patients developed minor complications. CONCLUSION: Partial division of puborectalis muscle combined with LIS is an effective technique in the management of anal hypertonia-associated anismus with satisfactory results and low incidence of complications.

Are early clinical manifestations of spasticity associated with long-term functional outcome following spinal cord injury? A retrospective study.

STUDY DESIGN: Retrospective study of a prospective cohort of patients with traumatic spinal cord injury (SCI). OBJECTIVES: Determine the relationship between the occurrence of early spasticity, defined as the development of signs and/or symptoms of spasticity during the hospitalization in traumatology, and the functional outcome 6-12 months following a SCI. Secondly, to determine the specific impact of early clonus, velocity-dependent hypertonia and/or muscle spasms on the functional outcome at the same timepoint. SETTING: Single trauma center specialized in SCI care. METHODS: One hundred sixty-two patients sustaining an acute traumatic SCI were included in the analyses. Comparative analysis was performed to describe the characteristics of patients with early spasticity. Correlations were performed to determine the relationship between the clinical signs of spasticity and the Spinal Cord Independence Measure (SCIM) scores collected 6-12 months after SCI. RESULTS: 51.9% of the cohort developed clinical signs of spasticity during the hospitalization in traumatology (29.7 days) following SCI. These showed a significantly lower total SCIM score and subscores compared to individuals without early spasticity at follow-up (p < 0.05). After adjusting for confounding factors, the occurrence of early spasms was only clinical sign of spasticity significantly associated with a decreased mobility at follow-up (r = -0.17, p = 0.04). CONCLUSIONS: The development of signs and symptoms of spasticity, in particular the occurrence of spasms in the first month following the injury may be associated with decreased functional outcome and mobility. Early assessment of spasticity following SCI is thus recommended.

Improving the objectivity of the current World Para Swimming motor coordination test for swimmers with hypertonia, ataxia and athetosis using measures of movement smoothness, rhythm and accuracy.

The current protocol for classifying Para swimmers with hypertonia, ataxia and athetosis involves a physical assessment where the individual's ability to coordinate their limbs is scored by subjective clinical judgment. The lack of objective measurement renders the current test unsuitable for evidence-based classification. This study evaluated a revised version of the Para swimming assessment for motor coordination, incorporating practical, objective measures of movement smoothness, rhythm error and accuracy. Nineteen Para athletes with hypertonia and 19 non-disabled participants performed 30 s trials of bilateral alternating shoulder flexion-extension at 30 bpm and 120 bpm. Accelerometry was used to quantify movement smoothness; rhythm error and accuracy were obtained from video. Para athletes presented significantly less smooth movement and higher rhythm error than the non-disabled participants (p < 0.05). Random forest algorithm successfully classified 89% of participants with hypertonia during out-of-bag predictions. The most important predictors in classifying participants were movement smoothness at both movement speeds, and rhythm error at 120 bpm. Our results suggest objective measures of movement smoothness and rhythm error included in the current motor coordination test protocols can be used to infer impairment in Para swimmers with hypertonia. Further research is merited to establish the relationship of these measures with swimming performance.

Cluster analysis of impairment measures to inform an evidence-based classification structure in RaceRunning, a new World Para Athletics event for athletes with hypertonia, ataxia or athetosis.

RaceRunning enables athletes with limited or no walking ability to propel themselves independently using a three-wheeled frame that has a saddle, handle bars and a chest plate. For RaceRunning to be included as a para athletics event, an evidence-based classification system is required. This study assessed the impact of trunk control and lower limb impairment measures on RaceRunning performance and evaluated whether cluster analysis of these impairment measures produces a valid classification structure for RaceRunning. The Trunk Control Measurement Scale (TCMS), Selective Control Assessment of the Lower Extremity (SCALE), the Australian Spasticity Assessment Scale (ASAS), and knee extension were recorded for 26 RaceRunning athletes. Thirteen male and 13 female athletes aged 24 (SD = 7) years participated. All impairment measures were significantly correlated with performance (rho = 0.55-0.74). Using ASAS, SCALE, TCMS and knee extension as cluster variables in a two-step cluster analysis resulted in two clusters of athletes. Race speed and the impairment measures were significantly different between the clusters (p < 0.001). The findings of this study provide evidence for the utility of the selected impairment measures in an evidence-based classification system for RaceRunning athletes.

Phrenic motor neuron loss in an animal model of early onset hypertonia.

Phrenic motor neuron (PhMN) development in early onset hypertonia is poorly understood. Respiratory disorders are one of the leading causes of morbidity and mortality in individuals with early onset hypertonia, such as cerebral palsy (CP), but they are largely overshadowed by a focus on physical function in this condition. Furthermore, while the brain is the focus of CP research, motor neurons, via the motor unit and neurotransmitter signaling, are the targets in clinical interventions for hypertonia. Furthermore, critical periods of spinal cord and motor unit development also coincide with the timing that the supposed brain injury occurs in CP. Using an animal model of early-onset spasticity (spa mouse [B6.Cg-Glrbspa/J] with a glycine receptor mutation), we hypothesized that removal of effective glycinergic neurotransmitter inputs to PhMNs during development will result in fewer PhMNs and reduced PhMN somal size at maturity. Adult spa (Glrb-/-), and wild-type (Glrb+/+) mice underwent unilateral retrograde labeling of PhMNs via phrenic nerve dip in tetramethylrhodamine. After three days, mice were euthanized, perfused with 4% paraformaldehyde, and the spinal cord excised and processed for confocal imaging. Spa mice had ~30% fewer PhMNs (P = 0.005), disproportionately affecting larger PhMNs. Additionally, a ~22% reduction in PhMN somal surface area (P = 0.019), an 18% increase in primary dendrites (P < 0.0001), and 24% decrease in dendritic surface area (P = 0.014) were observed. Thus, there are fewer larger PhMNs in spa mice. Fewer and smaller PhMNs may contribute to impaired diaphragm neuromotor control and contribute to respiratory morbidity and mortality in conditions of early onset hypertonia.NEW & NOTEWORTHY Phrenic motor neuron (PhMN) development in early-onset hypertonia is poorly understood. Yet, respiratory disorders are a common cause of morbidity and mortality. In spa mice, an animal model of early-onset hypertonia, we found ~30% fewer PhMNs, compared with controls. This PhMN loss disproportionately affected larger PhMNs. Thus, the number and heterogeneity of the PhMN pool are decreased in spa mice, likely contributing to the hypertonia, impaired neuromotor control, and respiratory disorders.