Significant Muscle Weakness Research Articles

Surgical Results of Lumbar Degenerative Disease with Foot Drop

Drop foot is associated with various diseases, such as peripheral nerve disease, lumbar degenerative disease, metabolic disease, and endocrine disease. Among lumbar degenerative diseases, lumbar disc herniation and lumbar canal stenosis are most commonly reported. We report the surgical outcomes of patients with drop foot caused by lumbar degenerative diseases. Between 2008 and 2018, we encountered 24 cases of drop foot in patients who underwent surgery of the lumbar lesion. The mean age was 69.5 years(49-88 years). Fourteen patients were male and ten were female. The mean time interval between the onset of drop foot and surgery was 51.5 days(from 7 days to 1 year). Drop foot, as a clinically significant muscle weakness, was defined at levels of manual muscle test(MMT)3 or lower. Responsible lesions for drop foot were canal stenosis at L4/5 in 8 cases, disc herniation at L4/5 in 10 cases, disc herniation at L5/S1 in 5 cases, and far-out syndrome in 1. One case involved drop foot bilaterally. Muscle weakness improved by surgery at levels of MMT 4 or greater in 16 cases(66.7%). Six cases of complete paresis or tibialis anterior muscle atrophy preoperatively resulted in no improvement;however, neuralgia was relieved in all. Twelve of 15 cases(80%)of lumbar disc herniation and 4 of 10 cases(40%)of lumbar canal stenosis resulted in improvement. Between disc herniation and canal stenosis, the surgical success rate was not statistically different. Age and the time interval between the onset and surgery were also not significant factors of the outcome. Surgical intervention seems to be beneficial even in cases of severe muscle weakness since pain relief can be expected, which leads to improvement in gait.

Genioglossus activation during maximal sniff manoeuvres: Is upper airway function relevant in the clinical assessment of inspiratory and expiratory muscle strength?

Genioglossus activation during maximal sniff manoeuvres: Is upper airway function relevant in the clinical assessment of inspiratory and expiratory muscle strength?

Characteristics of muscle function and the effect of cachexia in patients with haematological malignancy.

In this study, we investigated the muscle function of patients with haematological malignancy and healthy controls and examined the effect of cachexia on muscle function. Seventy-one patients with haematological malignancy, hospitalised for chemotherapy, and 71 healthy controls underwent examination of skeletal muscle mass (SMM; total body and upper and lower limbs), handgrip strength and isometric knee extensor strength. Patients with haematological malignancy were divided into three groups based on Glasgow Prognostic Score: non-cachexia (n=31), pre-cachexia (n=23) and cachexia (n=17) groups. The evaluation items were compared among the groups. Patients with haematological malignancy had lower SMM of the total body and lower limbs, handgrip strength and isometric knee extensor strength than healthy controls. There was no significant difference in SMM of the upper limbs among the groups. When classifying patients with haematological malignancy according to GPS, there was no significant difference among the three groups for any of the evaluation items. In patients with haematological malignancy, although significant muscle wasting and weakness were observed in the lower limbs, the effect of cachexia was minimal. The reduction in muscle function involved disuse syndrome, which accompanied a decline in physical activity.

Whole Body Vibration Methods with Survivors of Polio.

The purpose of the original study was to examine the use of whole body vibration (WBV) on polio survivors with and without post-polio syndrome as a form of weight bearing exercise. The goal of this article is to highlight the strengths, limitations, and applications of the method used. Fifteen participants completed two intervention blocks with a wash-out period in between the blocks. Each block consisted of twice a week (four weeks) WBV interventions, progressing from 10 to 20 min per session. Low intensity (peak to peak displacement 4.53 mm, frequency 24 Hz, g force 2.21) and higher intensity (peak to peak displacement 8.82 mm, frequency 35 Hz, g force 2.76) WBV blocks were used. Pain severity significantly improved in both groups following higher intensity vibration. Walking speed significantly improved in the group who participated in higher intensity intervention first. No study-related adverse events occurred. Even though this population can be at risk of developing overuse-related muscle weakness, fatigue, or pain from excessive physical activity or exercise, the vibration intensity levels utilized did not cause significant muscle weakness, pain, fatigue, or sleep disturbances. Therefore, WBV appears to provide a safe method of weight bearing exercise for this population. Limitations included the lack of measurement of reflexes, muscular activity, or circulation, the difficulty in participant recruitment, and insufficient strength of some participants to stand in recommended position. Strengths included a standard, safe protocol with intentional monitoring of symptoms and the heterogeneity of the participants in their physical abilities. An application of the methods is the home use of WBV to reduce the barriers associated with going to a facility for weight bearing exercise for longer term interventions, and benefits for conditions such as osteoporosis, particularly for aging adults with mobility difficulties due to paralysis or weakness. Presented method may serve as a starting point in future studies.

Whole Body Vibration Methods with Survivors of Polio

The purpose of the original study was to examine the use of whole body vibration (WBV) on polio survivors with and without post-polio syndrome as a form of weight bearing exercise. The goal of this article is to highlight the strengths, limitations, and applications of the method used. Fifteen participants completed two intervention blocks with a wash-out period in between the blocks. Each block consisted of twice a week (four weeks) WBV interventions, progressing from 10 to 20 min per session. Low intensity (peak to peak displacement 4.53 mm, frequency 24 Hz, g force 2.21) and higher intensity (peak to peak displacement 8.82 mm, frequency 35 Hz, g force 2.76) WBV blocks were used. Pain severity significantly improved in both groups following higher intensity vibration. Walking speed significantly improved in the group who participated in higher intensity intervention first. No study-related adverse events occurred. Even though this population can be at risk of developing overuse-related muscle weakness, fatigue, or pain from excessive physical activity or exercise, the vibration intensity levels utilized did not cause significant muscle weakness, pain, fatigue, or sleep disturbances. Therefore, WBV appears to provide a safe method of weight bearing exercise for this population. Limitations included the lack of measurement of reflexes, muscular activity, or circulation, the difficulty in participant recruitment, and insufficient strength of some participants to stand in recommended position. Strengths included a standard, safe protocol with intentional monitoring of symptoms and the heterogeneity of the participants in their physical abilities. An application of the methods is the home use of WBV to reduce the barriers associated with going to a facility for weight bearing exercise for longer term interventions, and benefits for conditions such as osteoporosis, particularly for aging adults with mobility difficulties due to paralysis or weakness. Presented method may serve as a starting point in future studies.

Therapeutic doses of neostigmine, depolarising neuromuscular blockade and muscle weakness in awake volunteers: a double-blind, placebo-controlled, randomised volunteer study.

Neostigmine reverses non-depolarising neuromuscular blockade, but may cause muscle weakness when administered after full recovery of neuromuscular function. We hypothesised that neostigmine in therapeutic doses impairs muscle strength and respiratory function in awake healthy volunteers. Twenty-one volunteers were randomised to receive two doses of either intravenous (i.v.) neostigmine 2.5mg with glycopyrrolate 450μg (neostigmine group, n=14) or normal saline 0.9% (placebo group, n=7). The first dose was administered immediately after obtaining baseline measurements, and the second dose was administered 15min later. All 14 volunteers in the neostigmine group received the first dose, mean (SD) 35 (5.8) μg.kg-1 , but only nine of these volunteers agreed to receive the second dose, 34 (3.5) ?g.kg-1 . The primary outcome was hand grip strength. Secondary outcomes were train-of-four ratio, single twitch height, forced expiratory volume in 1s, forced vital capacity, forced expiratory volume in 1s/forced vital capacity ratio, oxygen saturation, heart rate and mean arterial pressure. The first dose of intravenous neostigmine with glycopyrrolate resulted in reduced grip strength compared with placebo, -20 (20) % vs. +4.3 (9.9) %, p=0.0016; depolarising neuromuscular blockade with decreased single twitch height, -14 (11) % vs. -3.8 (5.6) %, p=0.0077; a restrictive spirometry pattern with decreased predicted forced expiratory volume in 1s, -15 (12) % vs. -0.47 (3.4) %, p=0.0011; and predicted forced vital capacity, -20 (12) % vs. -0.59 (3.2) %, p<0.0001 at 5min after administration. The second dose of neostigmine with glycopyrrolate further decreased grip strength mean (SD) -41 (23) % vs. +1.0 (15) %, p=0.0004; single twitch height -25 (15) % vs. -2.5 (6.6) %, p=0.0030; predicted forced expiratory volume in 1s -23 (24) % vs. -0.7 (4.4) %, p=0.0063; and predicted forced vital capacity, -27.1 (22.0) % vs. -0.66 (3.9) %, p=0.0010. Train-of-four ratio remained unchanged (p=0.22). In healthy volunteers, therapeutic doses of neostigmine induced significant and dose-dependent muscle weakness, demonstrated by a decrease in maximum voluntary hand grip strength and a restrictive spirometry pattern secondary to depolarising neuromuscular blockade.

Unilateral diaphragm paralysis: a dysfunction restricted not just to one hemidiaphragm

BackgroundMost patients with unilateral diaphragm paralysis (UDP) have unexplained dyspnea, exercise limitations, and reduction in inspiratory muscle capacity. We aimed to evaluate the generation of pressure in each hemidiaphragm separately and its contribution to overall inspiratory strength.MethodsTwenty-seven patients, 9 in right paralysis group (RP) and 18 in left paralysis group (LP), with forced vital capacity (FVC) < 80% pred, and 20 healthy controls (CG), with forced expiratory volume in 1 s (FEV1) > 80% pred and FVC > 80% pred, were evaluated for lung function, maximal inspiratory (MIP) and expiratory (MEP) pressure measurements, diaphragm ultrasound, and transdiaphragmatic pressure during magnetic phrenic nerve stimulation (PdiTw).ResultsRP and LP had significant inspiratory muscle weakness compared to controls, detected by MIP (− 57.4 ± 16.9 for RP; − 67.1 ± 28.5 for LP and − 103.1 ± 30.4 cmH2O for CG) and also by PdiTW (5.7 ± 4 for RP; 4.8 ± 2.3 for LP and 15.3 ± 5.7 cmH2O for CG). The PdiTw was reduced even when the non-paralyzed hemidiaphragm was stimulated, mainly due to the low contribution of gastric pressure (around 30%), regardless of whether the paralysis was in the right or left hemidiaphragm. On the other hand, in CG, esophagic and gastric pressures had similar contribution to the overall Pdi (around 50%). Comparing both paralyzed and non-paralyzed hemidiaphragms, the mobility during quiet and deep breathing, and thickness at functional residual capacity (FRC) and total lung capacity (TLC), were significantly reduced in paralyzed hemidiaphragm. In addition, thickness fraction was extremely diminished when contrasted with the non-paralyzed hemidiaphragm.ConclusionsIn symptomatic patients with UDP, global inspiratory strength is reduced not only due to weakness in the paralyzed hemidiaphragm but also to impairment in the pressure generated by the non-paralyzed hemidiaphragm.

An unusual case of shortness of breath.

SummaryMyopathy is a well-known complication of hypercortisolism and commonly involves proximal lower-limb girdle. We report a rare case of Cushing’s syndrome in a 60-year-old female presenting with significant respiratory muscle weakness and respiratory failure. She had history of rheumatoid arthritis, primary biliary cirrhosis and primary hypothyroidism and presented with weight gain and increasing shortness of breath. Investigations confirmed a restrictive defect with impaired gas transfer but with no significant parenchymatous pulmonary disease. Respiratory muscle test confirmed weakness of respiratory muscles and diaphragm. Biochemical and radiological investigations confirmed hypercortisolaemia secondary to a left adrenal tumour. Following adrenalectomy her respiratory symptoms improved along with an objective improvement in the respiratory muscle strength, diaphragmatic movement and pulmonary function test.Learning points:Cushing’s syndrome can present in many ways, a high index of suspicion is required for its diagnosis, as often patients present with only few of the pathognomonic symptoms and signs of the syndrome.Proximal lower-limb girdle myopathy is common in Cushing’s syndrome. Less often long-term exposure of excess glucocorticoid production can also affect other muscles including respiratory muscle and the diaphragm leading to progressive shortness of breath and even acute respiratory failure.Treatment of Cushing’s myopathy involves treating the underlying cause that is hypercortisolism. Various medications have been suggested to hinder the development of GC-induced myopathy, but their effects are poorly analysed.

The impact of percutaneous endoscopic gastrostomy on the survival of patients with amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a rapidly progressing degenerative motor neuron disease that leads to significant muscle weakness. Patients can present with severe dysphagia and require nutritional support. While percutaneous endoscopic gastrostomy (PEG) is a standard procedure for these patients, its effect on survival is not yet clear. Therefore, we aimed to evaluate the impact of PEG placement on ALS patients survival. We retrospectively reviewed health records of ALS patients followed at a Neurological Department in the northeast region of Portugal for the 2005–2016 period. Potentially relevant clinical information was collected for survival analysis using Kaplan–Meier estimator and Mantel–Cox regression. In the studied period, 75 incident ALS cases were identified. Information regarding symptom onset was available for 62 (83%) patients, and PEG was placed after informed consent in 27 (36%) patients. The overall median survival from symptom onset was 1142 (95% CI: 866–1418) days and did not differ between PEG and non-PEG groups (Fig. 1). In the PEG group ( n = 27), 19 (70%) died by the end of the follow-up period. Overall median survival post-PEG placement was 320 (95% CI: 135–505) days. Bulbar ALS cases ( n = 18) had a median survival of 249 days while the remaining 9 Spinal cases had a median survival of 709 days (Fig. 2). Both LogRank test and Mantel–Cox regression using ALS subtype as covariate did not yield significant results regarding post-PEG survival ( P = 0.312; HR = 0.566 [95% CI: 0.185–1.730], P = 0.566; respectively). In conclusion, PEG did not impact ALS survival in our study. Post-PEG survival was also similar in both bulbar- and spinal-onset groups. However, our analysis is limited by the small sample size. Studies with more participants are required to more effectively estimate the impact of PEG in overall and subgroups ALS survival.

Relationships between Lower Limb Muscle Strength Impairments and Physical Limitations in DM1.

Although adult and late-onset DM1 phenotypes DM1 present distinct lower limb weaknesses portraits, resulting physical limitations have never been described separately for each phenotype. To characterize the lower limb weaknesses and physical limitations among the DM1 adult and late-onset phenotypes separately and to document the contribution of weaknesses on mobility to optimize the management of this population. The strength of four muscle groups among 198 participants was quantified. Participants were categorized according to the severity of their muscular involvement using the Muscular Impairment Rating Scale (MIRS). Physical limitations were assessed using the Timed up-and-go (TUG), Berg Balance Scale (BBS) and 10 meters comfortable walking speed (10MWT). Multiple linear regressions were performed to identify the contribution of each muscle group to the mobility tests scores. Late-onset demonstrated less weakness and physical limitations (p < 0.001 - 0.002) than the adult phenotype, but 21.9-47.5% of participants with this phenotype showed mobility scores below reference values. Physical limitations were observed in the first two MIRS grades (37.5-42.1% of the participants) for the TUG and 10MWT. Ankle dorsiflexors and knee extensors were the two muscle groups that showed the strongest relationships with mobility scores. Although less impaired, the late-onset phenotype shows significant lower limb muscle weakness associated with physical limitations. The surprising presence of quantitative lower limb muscle weakness in the first two MIRS grades needs to be considered when using this scale. Both ankle dorsiflexors and knee extensors appear to be good indicators of physical limitations in DM1.

Mechanical ventilation modulates pro-inflammatory cytokine expression in spinal cord tissue after injury in rats

RationaleSpinal cord injury (SCI) may induce significant respiratory muscle weakness and paralysis, which in turn may cause a patient to require ventilator support. Central nervous system alterations can also exacerbate local inflammatory responses with immune cell infiltration leading to additional risk of inflammation at the injury site. Although mechanical ventilation is the traditional treatment for respiratory insufficiency, evidence has shown that it may directly affect distant organs through systemic inflammation. ObjectivesThis study aimed to better understand the impact of invasive mechanical ventilation on local spinal cord inflammatory responses following cervical or thoracic SCI. MethodsFive groups of female Sprague-Dawley rats were anesthetised for 24 h. Three groups received mechanical ventilation: seven rats without SCI, seven rats with cervical injury (C4-C5), and seven rats with thoracic injury (T10); whereas, two groups were non-ventilated: six rats without SCI; and six rats with thoracic injury (T10). Changes in inflammatory responses were determined in the spinal cord tissues collected at the local site of injury. Cytokines were measured using ELISA. Main resultsSCI induced local pro-inflammatory cytokine IL-6 expression for all groups. Mechanical ventilation also had effects on pro-inflammatory cytokines and independently increased TNF-α and decreased IL-1β levels in the spinal cords of anesthetized rats. ConclusionThese data provide the first evidence that mechanical ventilation contributes to local inflammation after SCI and in the absence of direct tissue injury.

Chapter 26 - Peripheral nerve disease

Polyneuropathies are common neurologic disorders affecting the peripheral nerves. There are a number of causes of damage to these structures, such as genetic and metabolic factors, autoimmune disorders, infection, drug or environmental toxicity, and malignancy. Motor and sensory impairments are commonly encountered in these conditions, leading to altered balance and gait with increased risk of falling. Diabetic neuropathy is the most common cause of peripheral nerve disease and extensive investigation of balance and walking function revealed greater postural instability and delayed activation of distal muscles during walking. Although classically thought to be due to sensory impairment, it is now recognized that a motor contribution to balance and gait impairment cannot be ruled out in diabetic neuropathy. Inflammatory and inherited neuropathies have had less investigation. Variations in static and dynamic balance and depend on the sensory afferents affected and the degree of motor impairment. Motor impairment is a major contributor to alterations in gait pattern. Exercise is an effective rehabilitation approach that can improve muscle strength and postural responses. The gains can carry over into improved functional balance and walking. Orthotic interventions are also promising in supporting joints where there is significant muscle weakness, but newer devices are being developed that provide sensory feedback, e.g., vibration, which may be effective where sensory impairment is a key contributor to postural instability.

Efficacy and safety of adrenocorticotropic hormone gel in refractory dermatomyositis and polymyositis

AimTo evaluate the efficacy, safety, tolerability and steroid-sparing effect of repository corticotropin injection (RCI), in an open-label clinical trial, in refractory adult polymyositis (PM) and dermatomyositis (DM).MethodsAdults with refractory PM...

Artificial Walking Technologies to Improve Gait in Cerebral Palsy: Multichannel Neuromuscular Stimulation.

Cerebral palsy (CP) is the most common childhood motor disability and often results in debilitating walking abnormalities, such as flexed-knee and stiff-knee gait. Current medical and surgical treatments are only partially effective in improving gait abnormalities and may cause significant muscle weakness. However, emerging artificial walking technologies, such as step-initiated, multichannel neuromuscular electrical stimulation (NMES), can substantially improve gait patterns and promote muscle strength in children with spastic CP. NMES may also be applied to specific lumbar-sacral sensory roots to reduce spasticity. Development of tablet computer-based multichannel NMES can leverage lightweight, wearable wireless stimulators, advanced control design, and surface electrodes to activate lower-limb muscles. Musculoskeletal models have been used to characterize muscle contributions to unimpaired gait and identify high muscle demands, which can help guide multichannel NMES-assisted gait protocols. In addition, patient-specific NMES-assisted gait protocols based on 3D gait analysis can facilitate the appropriate activation of lower-limb muscles to achieve a more functional gait: stance-phase hip and knee extension and swing-phase sequence of hip and knee flexion followed by rapid knee extension. NMES-assisted gait treatment can be conducted as either clinic-based or home-based programs. Rigorous testing of multichannel NMES-assisted gait training protocols will determine optimal treatment dosage for future clinical trials. Evidence-based outcome evaluation using 3D kinematics or temporal-spatial gait parameters will help determine immediate neuroprosthetic effects and longer term neurotherapeutic effects of step-initiated, multichannel NMES-assisted gait in children with spastic CP. Multichannel NMES is a promising assistive technology to help children with spastic CP achieve a more upright, functional gait.

P.128 - Broad clinical spectrum observed in patients with scapuloperoneal spinal muscular atrophy (SPSMA) caused by an c.806G > A (p. Arg269His) mutation in the TRPV4 gene

Scapuloperoneal spinal muscular atrophy (SPSMA) is a rare autosomal dominant disorder caused by heterozygous mutations in the transient receptor potential vanilloid 4 (TRPV4) gene. It is characterized by scapuloperoneal weakness and congenital contractures. Herein, we present two Polish SPSMA families harboring the same p.Arg269His mutation in TRPV4. In the first, the mutation was identified by direct Sanger sequencing of TRPV4 in the proband and then confirmed in other affected family members. For the second proband, clinical exome sequencing (TruSight One, Illumina) revealed the presence of the same de novo mutation. The mutation is known (HGMD, Clinvar) and was found not only in SPSMA individuals, but also in patients with Charcot-Marie-Tooth 2C. It is localized in a conserved protein region and predicted in silico to be pathogenic. The clinical spectrum observed in the first family was variable, although all members showed symptoms of skeletal dysplasia and mildly or non-progressive lower motoneuron disorder. The clinical presentation varied from mild (shortness of the clavicles with no sign of muscle weakness) to severe (hypotonia, severe congenital contractures, delayed motor milestones, short stature, global weakness and respiratory insufficiency). The proband from the second family, the first child of healthy young parents, presented with bilateral congenital talipes equinovarus, hypotonia and delayed motor milestones. At the age of five years, she was able to walk with calipers. In both families, EMG analysis revealed a neurogenic pattern, while her sensitive and motor nerve conduction velocities were normal. The SPSMA is characterized by an extremely variable clinical picture. We have observed an intrafamilial heterogeneity with a more severe phenotype in the following generations that is suggestive of anticipation.

Phenotype variability in patients with infantile spinal muscular atrophy: Distal muscle weakness and peripheral neuropathy in compound heterozygotes with SMN1 gene deletions

Objective: To present atypical phenotype with distal muscle weakness and neurographic signs of distal axonal degeneration in compound heterozygous patients with infantile spinal muscular atrophy (iSMA). Methods: Electromyography and neurography, molecular genetics DNA and RNA studies. Results: We present 4 patients with iSMA (1–18 years): 2 boys (onset age 2 and 3 monhtsmonths) and 2 girls (onset age 13 and 24 months, now wheelchair bound) with pronounced distal muscles weakness. Electromyoneurography revealed neurogenic pattern with severe axonal lesion in all patients. Both male patients died at the age 2 and 4 years. In two sibs (brother and sister) heterozygous paternal deletion of exon 7 and 8 was detected by MLPA, associated with maternal intragenic SMN1 gene missense mutation c689C>T p.S230L in exon 5. Prenatal diagnosis in the third pregnancy revealed only intragenic SMN1 gene mutation c689C>T p.S230L in exon 5, and healthy child was born. Next generation sequencing for hereditary neuropathies (clinical exome) revealed heterozygous paternal mutation c.505T>C; p.Y169H in the SH3TC2 gene in both sibs, confirmed by Sanger sequencing. In two other unrelated patients, compound heterozygosity of exons 7 and 8 deletion in SMN1 gene and intragenic missense mutation c821C>T(pT274I) in exon 6 was detected. Nerve biopsy confirmed loss of myelinated axons and axonal degeration in one of the female patients presented. Only one SMN2 gene copy was detected in all patients reported. Conclusion: Significant distal muscle weakness in patients with atypical iSMA might be result of distal axonal degeneration caused by intragenic SMN1 gene mutations probably aggravated by heterozygous missense mutation in SH3TC2 gene in two sibs and only one SMN2 copy in all patients. The functional consequences of point mutations are milder than of SMN1 deletions, since iSMA patients with one SMN2 copy generally have a congenitally lethal disease course, not seen in our patients.

Diagnosis of Duchenne Muscular Dystrophy in Italy in the last decade: Critical issues and areas for improvements

Despite all the advances in diagnosis and management of Duchenne muscular dystrophy over the past 50 years, the average age at diagnosis in most countries in the world around is still around 4–5 years. This retrospective study investigates the age at diagnosis in Italy in the past 10 years. We report findings from 384 boys who were diagnosed with DMD from 2005 to 2014. The mean age at first medical contact, which raised the suspicion of DMD, was 31 months. The mean age at diagnosis was 41 months. The finding that more frequently brought to suspect a DMD was the incidental finding of consistent elevated creatine kinase serum level detected during routine assessments in children undergoing general anesthesia or with intercurrent illness. This was followed by motor delay and signs of muscle weakness. Initial concerns were raised by general pediatricians (29%), specialists at tertiary centers (35%) or first level hospitals (23%). In children presenting incidental elevated creatine kinase values the diagnosis was achieved earlier than in children presenting a developmental delay. The mean age at diagnosis in our cohort was about 10–12 months lower than that reported in other countries.

Oral Dantrolene Causing a Decrease in Vital Capacity, Recurrent Lung Collapse, and Respiratory Failure in a Spinal Cord Injury Patient: A Case Report

Introduction: Dantrolene is a muscle relaxant used to treat malignant hyperthermia as well as muscle spasms in spinal cord injury patients. It is known to cause a decrease in skeletal muscle strength in humans, and inhibit diaphragm muscle strength in hamsters. There is at least one other case report of dantrolene leading to respiratory failure in a spinal cord injury patient. Here was present a case of a patient developing poor mucus clearance, lobar collapse and respiratoy failure after being started on dantrolene, and trend vital capacity and negative inspiratory force while titrating off dantrolene.Case: 47 y/o male with history of motor vehicle accident resulting in tetraplegia 19 months prior to admission, presented with pneumonia for the first time since his accident. He also experienced recurrently episodes of bilateral lung collapse and respiratory failure and was found to have significant respiratory muscle weakness. He had been started on dantrolene approximately six weeks prior to admission. After stopping dantrolene his clinical status and his vital capacity and negative inspiratory force dramatically improved. He was then able to clear his secretions, and had no further episodes of lung collapse.Discussion: Our case is only the second in literature of dantrolene causing respiratory failure in a spinal cord patient; and is the first to trend daily vital capacity and NIF while the patient is being tapered off the dantrolene. Our case documented a dramatic improvement NIV and VC after stopping dantrolene. Our case demonstrates the potential and avoidable harm of using dantrolene in group of patients for which is commonly prescribed.

Sleep-Disordered Breathing and Effects of Noninvasive Ventilation in Patients with Late-Onset Pompe Disease.

In neuromuscular disease, non-invasive ventilation (NIV) is indicated if sleep-disordered breathing (SDB) or significant respiratory muscle weakness (RMW) is present. We investigated immediate and long-term effects of NIV on sleep and nocturnal ventilation in patients with late-onset Pompe disease (LOPD). Polysomnography and transcutaneous capnometry were performed in 22 adult patients. If indicated, NIV was initiated the subsequent night and follow-up sleep studies were scheduled. Sleep quality and health-related quality of life (HRQoL) were self-assessed using standard questionnaires. Fourteen patients received enzyme replacement therapy (ERT), five patients were treatment-naÏve, and three individuals had previously stopped ERT. Fifteen patients reported symptoms of SDB, all showing abnormal sleep studies. Two patients had obstructive sleep apnea (OSA), three patients showed both OSA and nocturnal hypercapnia, four individuals had nocturnal hypercapnia, and two patients had both OSA and daytime hypercapnia. Four patients showed normal apnea-hypopnea index and CO2 measures but nocturnal tachypnea, orthopnea, and significant RMW were present. Supine forced vital capacity (FVC) and positional drop of FVC were independent predictors of SDB. In patients with SDB, HRQoL was significantly reduced. NIV was initiated in 15 individuals and led to significant improvement of ventilation and oxygenation in the first night of treatment. Follow-up sleep studies revealed stable normoxia and normocapnia without deterioration of sleep outcomes for up to 40 months. In LOPD, SDB is common and comprises both hypoventilation and OSA. NIV significantly improves respiration already in the first night of treatment. NIV warrants nocturnal long-term normoventilation without deterioration of sleep quality.

Gastrostomy tube placement is safe in advanced amyotrophic lateral sclerosis

Objectives: To evaluate the safety and effect on survival of insertion of a gastrostomy tube (G-tube) in patients with amyotrophic lateral sclerosis (ALS) who have upright forced vital capacity (uFVC) ≤ 50% predicted. Current guidelines, which are based on higher rates of post-procedure complications in ALS patients with advanced respiratory dysfunction, have led to a recommendation to perform G-tube insertion before the FVC drops to <50% predicted, even when the patient has no significant dysphagia.Methods: We assessed 41 ALS patients who received a G-tube, mostly by insertion of a percutaneous endoscopic gastrostomy (PEG) tube by a dedicated team that included a gastroenterologist and one of two anesthesiologists using Monitored Anesthesia Care with deep sedation, and 61 patients who did not receive a G-tube. uFVC was ≤50% predicted in 12 of 41 patients who received a G-tube and in 18 of 61 who did not.Results: The procedure was safe regardless of FVC status, with low rates of post-operative complications in both low and high FVC groups. There was no survival benefit for patients who received a G-tube when compared with those who did not.Discussion: PEG insertion is safe in ALS patients with significant respiratory muscle weakness when performed by a dedicated team, which suggests that the recommendation for G-tube placement should not be based on the patient’s respiratory status.