Occupational nerve injuries.

Occupational nerve injuries span a broad array of pathologies and contribute toward functional limitation, disability, and economic impact. Early and accurate recognition, treatment, and management of workplace factors rely on a thorough understanding of the anatomic and biomechanical factors that drive nerve injury. This review explores the interplay between anatomy, biomechanics, and nerve pathology common to occupational nerve injury and provides the treating physician with a rational, evidence-based approach to diagnosis and to occupational aspects of management. Assessment of potential occupational nerve injury begins with a detailed understanding of the employee's work duties through a biomechanical lens. One must consider likelihood of occupational causation while accounting for predisposing conditions or preexisting symptoms. Beyond overt crush injury or laceration, potential mechanisms of nerve injury, with effects compounded over time, include compression, stretch, vibration, and repetitive or high-force movements of regional muscles and joints. Injury often occurs at nerve locations that experience higher pressures, changes in pressure over time, or abrupt changes in trajectory, often near a tethered point. This understanding, coupled with condition-specific knowledge presented in this review, equips managing physicians to diagnose occupational nerve injury and enhance treatment recommendations with rational activity modifications or equipment that can protect the nerve or decrease likelihood of continued injury. Long-term management often involves follow-up to assess effectiveness of interventions in the setting of the work environment, with gradual progression of the worker toward return to unrestricted duty or to a point of maximal medical improvement.

Endocannabinoids and related lipids in serum from patients with amyotrophic lateral sclerosis.

BACKGROUND: The goals of this study were to determine whether serum concentrations of endocannabinoids (eCB) and related lipids predict disease status in patients with amyotrophic lateral sclerosis (ALS) relative to healthy controls, and whether concentrations correlate with disease duration and severity. METHODS: Serum concentrations of the eCBs 2-arachidonoylglycerol (2-AG) and N-arachidonoylethanolamine (AEA), and related lipids palmitoylethanolamine (PEA), oleoylethanolamine (OEA), and 2-oleoylglycerol (2-OG), were measured in samples from 47 patients with ALS and 19 healthy adults. Hierarchical binary logistic and linear regression analyses assessed whether lipid concentrations predicted disease status (ALS or healthy control), duration, or severity. RESULTS: Binary logistic regression revealed that, after controlling for age and gender, 2-AG, 2-OG and AEA concentrations were unique predictors of the presence of ALS, demonstrating odds ratios of 0.86 (P = .039), 1.03 (P = .023), and 42.17 (P = .026), respectively. When all five lipids and covariates (age, sex, race, ethnicity, body mass index, presence of a feeding tube) were included, the resulting model had an overall classification accuracy of 92.9%. Hierarchical linear regression analyses indicated that in patients with ALS, AEA and OEA inversely correlated with disease duration (P = .030 and .031 respectively), while PEA demonstrated a positive relationship with disease duration (P = .013). None of the lipids examined predicted disease severity. CONCLUSIONS: These findings support previous studies indicating significant alterations in concentrations of circulating lipids in patients with ALS. They suggest that arachidonic and oleic acid containing small lipids may serve as biomarkers for identifying the presence and duration of this disease.

MRI change metrics of facioscapulohumeral muscular dystrophy: Stir and T1.

INTRODUCTION: MRI evaluation in facioscapulohumeral muscular dystrophy (FSHD) demonstrates fatty replacement and inflammation/edema in muscle. Our previous work demonstrated short T1 inversion recovery (STIR)-hyperintense (STIR+) signal in muscle 2 years before fatty replacement. We evaluated leg muscle STIR changes and fatty replacement within 14 months. METHODS: FSHD subjects received 2 MRI scans of thigh and calf over a 6.9- to 13.8-month interval. Quality of life measures were collected. One Radiologist rated muscle changes on a semi-quantitative scale. RESULTS: Fifteen subjects completed longitudinal imaging. Four STIR + muscles and 3 STIR-normal (STIR-) muscles were rated as progressing to fatty tissue over the study period. DISCUSSION: STIR + muscles with confluent regions of fat at baseline increased more in fat, while STIR- muscles had increases in septal-fat over the study period. These changes may reflect two phases of FSHD, demonstrating MRI sensitivity is weighted toward gross pathological phases of the disease. Muscle Nerve 57: 905-912, 2018.

Therapeutic impact of systemic AAV-mediated RNA interference in a mouse model of myotonic dystrophy.

RNA interference (RNAi) offers a promising therapeutic approach for dominant genetic disorders that involve gain-of-function mechanisms. One candidate disease for RNAi therapy application is myotonic dystrophy type 1 (DM1), which results from toxicity of a mutant mRNA. DM1 is caused by expansion of a CTG repeat in the 3' UTR of the DMPK gene. The expression of DMPK mRNA containing an expanded CUG repeat (CUG(exp)) leads to defects in RNA biogenesis and turnover. We designed miRNA-based RNAi hairpins to target the CUG(exp) mRNA in the human α-skeletal muscle actin long-repeat (HSA(LR)) mouse model of DM1. RNAi expression cassettes were delivered to HSA(LR) mice using recombinant adeno-associated viral (rAAV) vectors injected intravenously as a route to systemic gene therapy. Vector delivery significantly reduced disease pathology in muscles of the HSA(LR) mice, including a reduction in the CUG(exp) mRNA, a reduction in myotonic discharges, a shift toward adult pre-mRNA splicing patterns, reduced myofiber hypertrophy and a decrease in myonuclear foci containing the CUG(exp) mRNA. Significant reversal of hallmarks of DM1 in the rAAV RNAi-treated HSA(LR) mice indicate that defects characteristic of DM1 can be mitigated with a systemic RNAi approach targeting the nuclei of terminally differentiated myofibers. Efficient rAAV-mediated delivery of RNAi has the potential to provide a long-term therapy for DM1 and other dominant muscular dystrophies.

Is electrodiagnosic testing for polyneuropathy overutilized?

Distal symmetric polyneuropathy (DSP) is one of the most common problems seen in clinical practice and one of the most frequent reasons for electrodiagnostic (EDx) testing. Most studies have supported the use of EDx testing for patients with suspected DSP. Some recent articles assert that EDx testing has a low yield in suspected DSP and is only needed for atypical presentations (a minority). However, many peer-reviewed articles indicate that EDx frequently changes diagnosis and management, and leads to a better understanding of the underlying pathology, severity, and prognosis. Overall, EDx is appropriate for most patients with new signs and symptoms of DSP. Muscle Nerve 55: 301-304, 2017.

Pain in hereditary neuropathy with liability to pressure palsy: an association with fibromyalgia syndrome?

INTRODUCTION: This study characterizes the nature of pain in hereditary neuropathy with liability to pressure palsy (HNPP). METHODS: This retrospective study was performed to assess duration, nature, location, and intensity of pain on initial presentation of subjects with HNPP, including the degree and type of analgesic medication use and electrodiagnostic characteristics. Subjects who met the American College of Rheumatology criteria for fibromyalgia syndrome (FMS) were also identified. RESULTS: Of 32 HNPP subjects, 24 (75%) had symptoms of pain, and 4 (12%) had pain as an initial symptom. Of subjects who described pain, 9 (28%) reported only musculoskeletal pain, 10 (31%) only neuropathic pain, and 5 (16%) both musculoskeletal and neuropathic pain. All 9 subjects with only musculoskeletal pain met criteria for FMS. CONCLUSIONS: Neuropathic and musculoskeletal pain occur commonly in HNPP and may be a presenting symptom. Additionally, HNPP with predominantly musculoskeletal pain may meet criteria for FMS and potentially delay the diagnosis.

Pain location and intensity impacts function in persons with myotonic dystrophy type 1 and facioscapulohumeral dystrophy with chronic pain.

INTRODUCTION: We examined the effects of pain site and intensity on function in patients with myotonic dystrophy type 1 (DM1) and facioscapulohumeral muscular dystrophy (FSHD) and chronic pain. METHODS: Questionnaires assessing pain sites, pain extent (number of sites), pain intensity, and pain interference were completed by 182 individuals with DM1 (43%) or FSHD (57%) and chronic pain. RESULTS: There was a positive association between pain extent and intensity with pain interference, and a negative association with psychological functioning in both DM1 and FSHD. Pain intensity at specific sites had differential impact beyond the effects of pain intensity alone. Head pain intensity independently affected psychological functioning, whereas leg, foot, hip, and knee pain contributed independently to the prediction of pain interference. CONCLUSIONS: Pain site and intensity differentially modulates the effect of chronic pain on function in DM1 and FSHD patients. Researchers and clinicians should consider these factors when assessing and treating pain.

Longitudinal features of STIR bright signal in FSHD.

INTRODUCTION: Magnetic resonance imaging of muscle shows short tau-inversion recovery (STIR) brightness in autosomal dominant facioscapulohumeral muscular dystrophy (FSHD1) suggestive of active inflammation/injury. We measured the longitudinal stability/progression of this potential disease biomarker. METHODS: Nine subjects underwent calf MRI imaging over 2 years. Two radiologists evaluated qualitative muscle changes. RESULTS: In 3/9 subjects, calf muscles demonstrated moderate/severe STIR hyperintensity at Time 1 that had progressed to fatty replacement 2 years later (Time 2). In the remaining subjects, moderate/severe muscle STIR abnormalities, when present, were consistent between exams. Mild STIR+ elevations had roughly similar patterns between exams. CONCLUSIONS: Moderate/severe STIR hyperintensities often foreshadow fatty replacement over a 2-year interval. Whether longer time courses are required to observe muscle degeneration and fatty replacement in some subjects remains to be explored.

ALSUntangled #74: Withania Somnifera (Ashwagandha).

ALSUntangled reviews alternative and off-label treatments on behalf of people with ALS (PALS) who ask about them. Here, we review withania somnifera (WS) commonly known as ashwagandha or winter cherry. WS has plausible mechanisms for slowing ALS progression because of its effects on inflammation, oxidative stress, autophagy, mitochondrial function, and apoptosis. Preclinical trials demonstrate that WS slows disease progression in multiple different animal models of ALS. Of the five individuals we found who described using WS for their ALS, two individuals reported moderate benefit while none reported experiencing any significant side effects. There is currently one clinical trial using WS to treat PALS; the results are not yet published. There are no serious side effects associated with WS and the associated cost of this treatment is low. Based on the above information, WS appears to us to be a good candidate for future ALS trials.

ALSUntangled #72: Insulin.

ALSUntangled reviews alternative and off-label treatments for people living with amyotrophic lateral sclerosis (PALS). Here we review insulin, which has at least one plausible mechanism for slowing ALS progression. However, pre-clinical studies are limited and there have been no trials in PALS yet. Insulin use in patients without a metabolic need may cause very serious and potentially lethal side effects. While further studies to evaluate potential benefits may be warranted, at this time we cannot endorse insulin treatment to slow ALS progression.

ALSUntangled #75: Portable neuromodulation stimulator therapy.

Spurred by patient interest, ALSUntangled herein examines the potential of the Portable Neuromodulation Stimulator (PoNS™) in treating amyotrophic lateral sclerosis (ALS). The PoNS™ device, FDA-approved for the treatment of gait deficits in adult patients with multiple sclerosis, utilizes translingual neurostimulation to stimulate trigeminal and facial nerves via the tongue, aiming to induce neuroplastic changes. While there are early, promising data for PoNS treatment to improve gait and balance in multiple sclerosis, stroke, and traumatic brain injury, no pre-clinical or clinical studies have been performed in ALS. Although reasonably safe, high costs and prescription requirements will limit PoNS accessibility. At this time, due to the lack of ALS-relevant data, we cannot endorse the use of PoNS as an ALS treatment.

From 32 ounces to zero: a medical geographic study of dispensing a cultivated batch of "plum" cannabis flowers to medical marijuana patients in Washington State.

The medicinal use of cannabis is a growing phenomenon in the U.S. predicated on the success of overcoming specific spatial challenges and establishing particular human-environment relationships. This article takes a medical geographic "snapshot" of an urban site in Washington State where qualifying chronically ill and debilitated patients are delivered locally produced botanical cannabis for medical use. Using interview, survey, and observation, this medical geographic research project collected information on the social space of the particular delivery site and tracked the production cost, reach, and health value of a 32-ounce batch of strain-specific medical cannabis named "Plum" dispensed over a four-day period. A convenience sample of 37 qualifying patients delivered this batch of cannabis botanical medicine was recruited and prospectively studied with survey instruments. Results provide insight into patients' self-rated health, human-plant relationships, and travel-to-clinic distances. An overall systematic geographic understanding of the medical cannabis delivery system gives a grounded understanding of the lengths that patients and care providers go, despite multiple hurdles, to receive and deliver treatment with botanical cannabis that relieves diverse symptoms and improves health-related quality-of-life.

Patient Reported Outcomes Using Medical Cannabis for Managing Pain in Charcot-Marie-Tooth Disease.

Objective: Chronic pain is a major problem for patients with Charcot-Marie-Tooth (CMT) disease. This exploratory study examined patient reported efficacy of medical cannabis for pain management in this population. Methods: Participants (N = 56; 71.4% female; Age = 48.9, SD = 14.6; 48.5% CMT1) were recruited though the Hereditary Neuropathy Foundation. The online survey contained 52 multiple choice questions about demographics, medical cannabis use, symptomology, efficacy, and adverse effects. Results: Nearly all (90.9%) of respondents reported experiencing pain, including all (100%) females and 72.7% of males (chi-square P < .05) with 91.7% of respondents indicating cannabis provided at least 50% pain relief. The most frequent response was an 80% reduction in pain. Moreover, 80.0% of respondents reported using less opiates, 69% noted using less sleep medication, and 50.0% reported using less anxiety/antidepressant medications. Negative side effects were noted by 23.5% of respondents. However, almost all (91.7%) of that subgroup did not have plans to stop consuming cannabis. One-third (33.9%) possessed a medical cannabis certificate. Patient perceptions of their physicians' attitudes regarding patient medical cannabis use greatly impacted whether respondents informed their providers of their usage. Conclusion: The vast majority of patients with CMT reported that cannabis was effective to manage pain symptoms. These data support the need for prospective, randomized, controlled trials using standardized dosing protocols to further delineate and optimize the potential use of cannabis to treat pain related to CMT.

ALSUntangled #66: antimycobacterial antibiotics.

Several infections have been associated with motor neuron diseases resembling ALS, including species of viruses, bacteria, and parasites. Mycobacterium avium subspecies paratuberculosis (MAP), most known for its probable etiologic association with Crohn's disease, has been suggested as another possible infectious cause of motor neuron disease. Two published case reports describe the successful treatment of ALS-like symptoms with antimycobacterial antibiotics. Both cases had atypical features. Based on these, we believe it would be reasonable to begin performing chest imaging in PALS who have features of their history or exam that are atypical for ALS such as pain, fevers, or eye movement abnormalities. If the chest imaging is abnormal, more specific testing for mycobacteria may be indicated. Until there is more clear evidence of an association between mycobacteria and ALS, we cannot endorse the widespread use of potentially toxic antimycobacterial antibiotics for PALS.

ALSUntangled #68: ozone therapy.

ALSUntangled reviews alternative and off-label treatments for people living with amyotrophic lateral sclerosis (PALS). Here we review ozone therapy. Ozone therapy has possible mechanisms for slowing ALS progression based on its antioxidant, anti-inflammatory, and mitochondrial effects. A non-peer-reviewed report suggests that ozone treatment may slow progression in a mTDP-43 mouse model of ALS. One verified "ALS reversal" occurred on a cocktail of alternative treatments including ozone. There are no ALS trials using ozone to treat PALS. There can be potentially serious side effects associated with ozone therapy, depending on the dose. Based on the above information, we support an investigation of ozone therapy in ALS cell or animal models but cannot yet recommend it as a treatment in PALS.

ALSUntangled # 69: astaxanthin.

ALSUntangled reviews alternative and off-label treatments for people living with amyotrophic lateral sclerosis (PALS). Here we review astaxanthin which has plausible mechanisms for slowing ALS progression including antioxidant, anti-inflammatory, and anti-apoptotic effects. While there are no ALS-specific pre-clinical studies, one verified "ALS reversal" occurred in a person using a combination of alternative therapies which included astaxanthin. There have been no trials of astaxanthin in people living with ALS. Natural astaxanthin appears to be safe and inexpensive. Based on the above information, we support further pre-clinical and/or clinical trials of astaxanthin in disease models and PALS, respectively, to further elucidate efficacy.

ALSUntangled #63: ketogenic diets.

ALSUntangled reviews alternative and off label treatments with a goal of helping patients make more informed decisions about them. Here we review ketogenic diets. We shows that these have plausible mechanisms, including augmenting cellular energy balance and reducing excitotoxicity, neuroinflammation and oxidative stress. We review a mouse model study, anecdotal reports and trials in ALS and other diseases. We conclude that there is yet not enough data to recommend ketogenic diets for patients with ALS, especially in light of the many side effects these can have.

ALSUntangled #67: rituximab.

ALSUntangled reviews alternative and off-label treatments on behalf of people with ALS who ask about them. Here we review rituximab, a drug which specifically depletes B lymphocytes. We show a current lack of evidence for a role of these cells in ALS progression. The one patient we found who described using Rituximab for their ALS found no benefit. Given all this, and the known serious risks of rituximab, we advise against its use as an ALS treatment.

ALSUntangled #70: caffeine.

ALSUntangled reviews alternative and off-label treatments for people living with amyotrophic lateral sclerosis (PALS). Here, we review caffeine which has plausible mechanisms for slowing ALS progression. However, pre-clinical studies are contradictory, and a large case series showed no relationship between caffeine intake and ALS progression rate. While low doses of caffeine are safe and inexpensive, higher doses can cause serious side effects. At this time, we cannot endorse caffeine as a treatment to slow ALS progression.