Showing papers in "Muscle & Nerve in 2015"

Measurement of intramuscular fat by muscle echo intensity.

Abstract: Introduction: The aim of this study was to compare ultrasound echo intensity (EI) with high-resolution T1-weighted MRI and to establish calibration equations to estimate percent intramuscular fat from EI. Methods: Thirty-one participants underwent both ultrasound and MRI testing of 4 muscles: rectus femoris (RF); biceps femoris (BF); tibialis anterior (TA); and medial gastrocnemius (MG). Results: Strong correlations were found between MRI percent fat and muscle EI after correcting for subcutaneous fat thickness (r = 0.91 in RF, r = 0.80 in BF, r = 0.80 in TA, r = 0.76 in MG). Three types of calibration equations were established. Conclusions: Muscle ultrasound is a practical and reproducible method that can be used as an imaging technique for examination of percent intramuscular fat. Future ultrasound studies are needed to establish equations for other muscle groups to enhance its use in both research and clinical settings. Muscle Nerve, 2015

Spinal Muscular Atrophy: Diagnosis and Management in a New Therapeutic Era

Abstract: Spinal muscular atrophy (SMA) describes a group of disorders associated with spinal motor neuron loss. In this review we provide an update regarding the most common form of SMA, proximal or 5q-SMA, and discuss the contemporary approach to diagnosis and treatment. Electromyography and muscle biopsy features of denervation were once the basis for diagnosis, but molecular testing for homozygous deletion or mutation of the SMN1 gene allows efficient and specific diagnosis. In combination with loss of SMN1, patients retain variable numbers of copies of a second similar gene, SMN2, which produces reduced levels of the survival motor neuron (SMN) protein that are insufficient for normal motor neuron function. Despite the fact that understanding of how ubiquitous reduction of SMN protein leads to motor neuron loss remains incomplete, several promising therapeutics are now being tested in early-phase clinical trials.

An overview of polymyositis and dermatomyositis.

Abstract: Polymyositis and dermatomyositis are inflammatory myopathies that differ in their clinical features, histopathology, response to treatment, and prognosis. Although their clinical pictures differ, they both present with symmetrical, proximal muscle weakness. Treatment relies mainly upon empirical use of corticosteroids and immunosuppressive agents. A deeper understanding of the molecular pathways that drive pathogenesis, careful phenotyping, and accurate disease classification will aid clinical research and development of more efficacious treatments. In this review we address the current knowledge of the epidemiology, clinical characteristics, diagnostic evaluation, classification, pathogenesis, treatment, and prognosis of polymyositis and dermatomyositis.

Diagnostic evaluation of rhabdomyolysis.

Abstract: Rhabdomyolysis is characterized by severe acute muscle injury resulting in muscle pain, weakness, and/or swelling with release of myofiber contents into the bloodstream. Symptoms develop over hours to days after an inciting factor and may be associated with dark pigmentation of the urine. Serum creatine kinase and urine myoglobin levels are markedly elevated. Clinical examination, history, laboratory studies, muscle biopsy, and genetic testing are useful tools for diagnosis of rhabdomyolysis, and they can help differentiate acquired from inherited causes of rhabdomyolysis. Acquired causes include substance abuse, medication or toxic exposures, electrolyte abnormalities, endocrine disturbances, and autoimmune myopathies. Inherited predisposition to rhabdomyolysis can occur with disorders of glycogen metabolism, fatty acid β-oxidation, and mitochondrial oxidative phosphorylation. Less common inherited causes of rhabdomyolysis include structural myopathies, channelopathies, and sickle-cell disease. This review focuses on the differentiation of acquired and inherited causes of rhabdomyolysis and proposes a practical diagnostic algorithm. Muscle Nerve 51: 793-810, 2015.

Effects of smartphone overuse on hand function, pinch strength, and the median nerve

Abstract: Introduction In this study we investigated the flexor pollicis longus (FPL) tendon and median nerve in smartphone users by ultrasonography to assess the effects of smartphone addiction on the clinical and functional status of the hands. Methods: One hundred two students were divided into 3 groups: non-users, and high or low smartphone users. Smartphone Addiction Scale (SAS) scores and grip and pinch strengths were recorded. Pain in thumb movement and rest and hand function were evaluated on the visual analog scale (VAS) and the Duruoz Hand Index (DHI), respectively. The cross-sectional areas (CSAs) of the median nerve and the FPL tendon were calculated bilaterally using ultrasonography. Results: Significantly higher median nerve CSAs were observed in the dominant hands of the high smartphone users than in the non-dominant hands (P < 0.001). SAS scores correlated with VAS pain for movement and rest, DHI scores, and pinch strength (P < 0.05; r = 0.345, 0.272, 0.245, and 0.281, respectively). Conclusions: Smartphone overuse enlarges the median nerve, causes pain in the thumb, and decreases pinch strength and hand functions. Muscle Nerve, 2015 Muscle Nerve 52: 183–188, 2015

Effects of exercise with and without different degrees of blood flow restriction on torque and muscle activation.

Abstract: Introduction An unresolved question in resistance training combined with blood flow restriction (BFR) is what percentage of estimated arterial occlusion pressure provides the most robust acute muscular response Methods Forty participants were assigned to Experiments 1, 2, or 3 Each experiment completed exercise protocols differing by pressure, exercise load, and/or volume Torque was measured pre- and postexercise, and muscle activation was measured pre- and during each set Results Pressure and load did not affect torque greatly Muscle activation increased in all conditions (P < 005) and was higher with 30% 1RM compared with 20% 1RM Pressure appeared to increase muscle activation from 40% to 50% arterial occlusion [66% vs 87% maximal voluntary contraction (30% 1RM)] but was not further increased with higher pressure Conclusion Different levels of BFR may alter the acute muscular response to a degree, although higher pressures do not appear to augment these changes Muscle Nerve 51:713–721, 2015

Clinical and genetic associations of autoantibodies to 3-hydroxy-3-methyl-glutaryl-coenzyme a reductase in patients with immune-mediated myositis and necrotizing myopathy.

Abstract: Introduction: Inhibition of 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGCR) with statins may trigger idiopathic inflammatory myositis (IIM) or immune-mediated necrotizing myopathy (IMNM). Anti-HMGCR antibodies have been detected in patients with IIM/IMNM. We aimed to determine the associations of anti-HMGCR in IIM/IMNM. Methods: Anti-HMGCR antibodies were detected by ELISA in sera from patients with IIM/IMNM. Results: Anti-HMGCR antibodies were detected in 19 of 207 patients with IIM/IMNM, and there was a trend toward an association with male gender (P = 0.079). Anti-HMGCR antibodies were associated strongly with statin exposure (OR = 39, P = 0.0001) and HLA-DRB1*11 (OR = 50, P < 0.0001). The highest risk for development of anti-HMGCR antibodies was among HLA-DR11 carriers exposed to statins. Univariate analysis showed a strong association of anti-HMGCR antibodies with diabetes mellitus (P = 0.008), which was not confirmed by multiple regression. Among anti-HMGCR+ patients there was a trend toward increased malignancy (P = 0.15). Conclusions: Anti-HMGCR antibodies are seen in all subtypes of IIM and IMNM and are associated strongly with statin use and HLA-DR11.

Combining MRI and muscle biopsy improves diagnostic accuracy in subacute-onset idiopathic inflammatory myopathy.

Abstract: Introduction: In 10-20% of patients with subacute- onset idiopathic inflammatory myopathy (IIM), muscle biopsy is normal or shows nonspecific findings. MRI can be used as a tri- age test before muscle biopsy and as an add-on test if the biopsy is nondiagnostic. Methods: MRI scans of skeletal muscles and muscle biopsies were evaluated prospectively in 48 patients suspected to have IIM. The interpretations of MRI and muscle biopsy were compared with the definite diagnosis (based on European Neuromuscular Centre criteria and response to corticosteroids). Results: The false negative rate (FNR) of all muscle biopsies was 0.23. Biopsies of a muscle showing hyperintensity on MRI (as triage test) had an FNR of 0.19. The result of MRI as an add-on test in patients with a nondiagnostic muscle biopsy decreased the FNR from 0.23 to 0.06. Conclusions: We recommend both MRI and muscle biopsy in patients suspected of having IIM. Muscle Nerve 51: 253-258, 2015 Adult subacute-onset idiopathic inflammatory myopathies (IIM) are subclassified into polymyosi- tis (PM), dermatomyositis (DM), nonspecific myo- sitis (NSM), and necrotizing autoimmune

Myasthenia gravis associated with ipilimumab and nivolumab in the treatment of small cell lung cancer.

Abstract: laboratory examinations (erythrocyte sedimentation rate, C-reactive protein, and complete blood count) were otherwise normal. Sonography (Philips iU22 Ultrasound system with a L12-5 50 mm linear transducer) demonstrated a hypoechoic mass of the semitendinosus muscle, which had ill-defined margins. On axial and sagittal images (Fig. 1A,B), the semitendinosus muscle was infiltrated and enlarged. Muscle fibers were thickened, but their orientation was preserved. Doppler examination showed both central and peripheral hypervascularity of the muscle lesion. There was no extension to the adjacent hamstring muscles (biceps femoris or semimembranosus). MR imaging showed focal enlargement of the semitendinosus muscle, with normal signal intensity on T1-weighted images and homogeneous hyperintensity on STIR images. Homogeneous enhancement was observed after intravenous gadolinium administration (Fig. 1C). No other lesions were noted. Swelling and pain disappeared spontaneously within 2 weeks. A follow-up examination performed 4 weeks later showed complete resolution of MR abnormalities (Fig. 1D). The patient made a complete recovery. Long-term follow-up confirmed the final diagnosis of focal myositis. Focal myositis is a rare, benign, soft tissue pseudotumor, which was first described by Heffner et al. Isolated cases have been published, but only 1 study described MRI features in a series of 8 patients. The etiology is unknown. Focal myositis may affect both children and adults. Skeletal muscles of the lower extremities are typically involved, and the most commonly affected site is the thigh. Other locations have been reported. Steroids are commonly used for treatment, but the natural history is for disappearance without treatment. Several authors have described possible recurrence or evolution to polymyositis. The typical appearance on MR imaging is an isointense or slightly hypointense signal on T1-weighted unenhanced images with homogeneous contrast enhancement. Lesions are hyperintense on STIR sequences. MRI may occasionally show the persistence of muscle fiber orientation. The sonographic features of focal myositis have not been described previously. In our patient, sonography showed hypoechoic enlargement of the muscle. Ultrasound can more readily show the thickening of muscle fibers with persistence of fiber orientation better than any other imaging modality. In this patient, there was no history of trauma. Infectious myositis is another cause of myositis, but the clinical and laboratory features were not were not consistent with infection. Other inflammatory processes could be considered, such as proliferative fasciitis, but it was excluded due to the intramuscular location of the lesion. The only other pathology that we considered was polymyositis with focal onset. Because histology cannot differentiate between focal myositis and polymyositis with focal onset, muscle biopsy was not performed. Instead, follow-up examination showed disappearance of abnormalities, and was not consistent with proliferative myositis, polymyositis, or dermatomyositis. In conclusion, we report the sonographic features of focal myositis. In the evaluation of an intramuscular mass, the persistence of fiber orientation can be considered a valuable sign to suggest myositis and rule out a neoplasm. However, one should also consider other inflammatory processes in the differential diagnosis. Long-term follow-up is necessary given the possible evolution to polymyositis, dermatomyositis, or proliferative myositis.

Non-invasive assessment of muscle stiffness in patients with Duchenne muscular dystrophy.

Abstract: Introduction: Assessment of muscle mechanical properties may provide clinically valuable information for follow- up of patients with Duchenne muscular dystrophy (DMD) through the course of their disease. In this study we aimed to assess the effect of DMD on stiffness of relaxed muscles using elastography (supersonic shear imaging). Methods: Fourteen DMD patients and 13 control subjects were studied. Six muscles were measured at 2 muscle lengths (shortened and stretched): gastrocnemius medialis (GM); tibialis anterior (TA); vastus lateralis (VL); biceps brachii (BB); triceps brachii (TB); and abductor digiti minimi (ADM). Results: Stiffness was signifi- cantly higher in DMD patients compared with controls for all the muscles (main effect for population, P <0.033 in all cases), except for ADM. The effect size was small (d 50.33 for ADM at both muscle lengths) to large (d 50.86 for BB/stretched). Con- clusions: Supersonic shear imaging is a sensitive non-invasive technique to assess the increase in muscle stiffness associated with DMD. Muscle Nerve 51: 284-286, 2015

Isaacs syndrome: A review

Abstract: Isaacs syndrome is a peripheral nerve hyperexcitability (PNH) syndrome that presents as continuous motor activity. Clinical findings include cramps, fasciculations, and myokymia. Electrodiagnosis plays a key role in diagnosis by demonstrating after-discharges on nerve conduction studies, and fasciculation potentials, myokymic discharges, neuromyotonic discharges, and other types of abnormal spontaneous activity on needle examination. Etiopathogenesis involves the interaction of genetic, autoimmune, and paraneoplastic factors, which requires a broad-ranging evaluation for underlying causes. Initial treatment is symptomatic, but immune therapy is often needed and can be effective. The purpose of this review is to describe the syndrome and its pathogenesis, assist the reader in evaluating patients with suspected Isaacs syndrome and distinguishing it from other disorders of PNH, and suggest an approach to management, including both symptomatic and immunomodulating therapy.

Magnetic resonance imaging pattern recognition in sporadic inclusion-body myositis

Abstract: Introduction: In sporadic inclusion-body myositis (IBM), additional tools are needed to confirm the diagnosis, particularly in clinically atypical or pathologically unproven patients. The aims of this study were to define the pattern of muscle MRI in IBM and to assess its accuracy in differentiating IBM from other myopathies that overlap with it clinically or pathologically. Methods: Blind assessment was done on the scans of 17 definite IBM, 2 possible IBM, and 118 patients with other myopathies. Results: The diagnostic accuracy to detect definite IBM was 95% for the typical pattern (with 100% specificity) and 97% for both typical and consistent patterns (with 97% specificity). Conclusions: Muscle MRI is an accurate tool for diagnostic work-up of suspected IBM patients and may be particularly helpful in patients with early disease or who lack the classical IBM pathology. Muscle Nerve, 2015

Ultrasonographic identification of nerve pathology in neuralgic amyotrophy: Enlargement, constriction, fascicular entwinement, and torsion

Abstract: Introduction The aim of this study was to characterize the ultrasonographic findings on nerves in neuralgic amyotrophy. Methods Fourteen patients with neuralgic amyotrophy were examined using high-resolution ultrasound. Results Four types of abnormalities were found: (1) focal or diffuse nerve/fascicle enlargement (57%); (2) incomplete nerve constriction (36%); (3) complete nerve constriction with torsion (50%; hourglass-like appearance); and (4) fascicular entwinement (28%). Torsions were confirmed intraoperatively and were seen on the radial nerve in 85% of patients. A significant correlation was found between no spontaneous recovery of nerve function and constriction/torsion/fascicular entwinement (P = 0.007). Conclusion Ultrasonographic nerve pathology in neuralgic amyotrophy varies in order of severity from nerve enlargement to constriction to nerve torsion, with treatment ranging from conservative to surgical. We postulate that the constriction caused by inflammation is the precursor of torsion and that development of nerve torsion is facilitated by the rotational movements of limbs. Muscle Nerve 52: 503–511, 2015

The composition of cellular infiltrates in anti-HMG-CoA reductase-associated myopathy.

Abstract: Objective To characterize cellular infiltrates in muscle biopsies from patients with anti-3-hydroxy-3-methyl-gulatryl-CoA reductase (HMGCR)-associated myopathy.

Different types of upper extremity exercise training in Duchenne muscular dystrophy: effects on functional performance, strength, endurance, and ambulation.

Abstract: Introduction We investigated and compared the effects of 2 different types of upper extremity exercise training on upper extremity function, strength, endurance, and ambulation in patients with early-stage Duchenne muscular dystrophy (DMD). Methods The study group (n = 12) exercised with an arm ergometer under the supervision of a physiotherapist, whereas the control group (n = 12) underwent a strengthening range-of-motion (ROM) exercise program under the supervision of their families at home for 8 weeks. Upper extremity functional performance, strength, endurance, and ambulatory status were assessed before and after the training. Results Ambulation scores, endurance, and arm functions, as well as proximal muscle strength, were improved after the training in the study group (P < 0.05). Conclusions These results demonstrate that upper extremity training with an arm ergometer is more effective in preserving and improving the functional level of early-stage DMD patients compared to ROM exercises alone. Muscle Nerve 51:697–705, 2015

Whole-body magnetic resonance imaging evaluation of facioscapulohumeral muscular dystrophy.

Abstract: Introduction: Facioscapulohumeral muscular dystrophy (FSHD) is a hereditary disorder that causes progressive muscle wasting. Increasing knowledge of the pathophysiology of FSHD has stimulated interest in developing biomarkers of disease severity. Methods: Two groups of MRI scans were analyzed: whole-body scans from 13 subjects with FSHD; and upper and lower extremity scans from 34 subjects with FSHD who participated in the MYO-029 clinical trial. Muscles were scored for fat infiltration and edema-like changes. Fat infiltration scores were compared with muscle strength and function. Results: The analysis revealed a distinctive pattern of both frequent muscle involvement and frequent sparing in FSHD. Averaged fat infiltration scores for muscle groups in the legs correlated with quantitative muscle strength and 10-meter walk times. Conclusions: Advances in MRI technology allow for acquisition of rapid, high-quality, whole-body imaging in diffuse muscle disease. This technique offers a promising disease biomarker in FSHD and other muscle diseases. Muscle Nerve 52: 512–520, 2015

Autonomic system and amyotrophic lateral sclerosis.

Abstract: Introduction: The aim of this study is to characterize autonomic impairment in motor neuron disease. Methods: Neurological evaluations and autonomic testing were analyzed retrospectively in 132 patients: 86 classic amyotrophic lateral sclerosis (ALS), 36 lower motor neuron (LMN), and 10 upper motor neuron (UMN) predominant disease. Results: One-third of patients were symptomatic; urinary urgency and constipation were the most frequent symptoms. Increased Composite Autonomic Severity Score (CASS) was present in 75% with mild impairment (CASS 1–3) in 85% and moderate (CASS 4–7) in 15%. The frequencies of testing abnormalities were: sudomotor 46%, cardiovagal 50%, and adrenergic 14%. The UMN group had significantly higher median CASS scores than the classic ALS (P = 0.021) and LMN group (P = 0.018). Conclusions: We found predominantly mild autonomic impairment in ALS patients, with mostly cardiovagal and sudomotor involvement. Moderate autonomic failure occurred in 1 of 7 patients, especially those with an UMN presentation. Patients with selective corticospinal tract involvement may have more impairment of autonomic pathways. Muscle Nerve 51:676–679, 2015

Corneal confocal microscopy for the diagnosis of diabetic autonomic neuropathy.

Abstract: BACKGROUND: Diabetic autonomic neuropathy (DAN) results in increased morbidity and mortality. The early diagnosis of DAN can be difficult and is commonly evaluated using cardiac autonomic function tests as a surrogate. However, they are not widely available, have limited sensitivity and specificity, and can be confounded by concomitant cardiovascular disease and medications. METHODS: The diagnostic utility of corneal confocal microscopy for diagnosis of DAN was assessed. Thirty-four diabetic patients without [Composite Autonomic Scoring Scale (CASS)?2] vs with (CASS>2) DAN and 18 healthy control subjects (HC) underwent detailed assessment of somatic and autonomic neuropathy, Composite Autonomic Symptom Scale (COMPASS), (CASS), and Corneal Confocal Microscopy (CCM). RESULTS: Corneal nerve fiber density, branch density, and length showed a progressive and significant reduction in patients with DAN vs HC and those without DAN. CCM correlated highly significantly with COMPASS and CASS, and corneal nerve fiber parameters demonstrated a high sensitivity and specificity for diagnosis of DAN. CONCLUSIONS: This study demonstrates that corneal nerve damage detected using CCM can be deployed to diagnose subclinical and overt DAN. It therefore represents a rapid, non-invasive, highly sensitive and specific diagnostic test for DAN. Muscle Nerve, 2015.

Contact heat evoked potentials: Normal values and use in small-fiber neuropathy

Abstract: Introduction Contact heat evoked potentials (CHEPs) may be an objective, non-invasive diagnostic tool in small-fiber neuropathy (SFN). This study establishes normal CHEP values and examines their applicability in SFN patients. Methods: Standardized CHEPs were administered at the wrist and ankle. The N2 and P2 latencies and N2–P2 peak–peak amplitude were recorded by electroencephalography. We examined healthy subjects (n = 97), stratified by age and gender, and SFN patients with abnormal intraepidermal nerve fiber density (n = 42). CHEP reproducibility and interobserver values were also investigated. Results: CHEP normative values were determined. There was a 9–16% increase in latency per centimeter of height with increasing age. Amplitudes were higher in women than men, and decreased (17–71%) with aging. Test-retest reproducibility and interobserver values were >0.61 and >0.96, respectively. CHEPs were abnormal in 73.8% of the patients. Conclusion: In this study we have established normal values, reliability, and clinical applicability of CHEPs in SFN. Muscle Nerve, 2015 Muscle Nerve 51:743–749, 2015

Outcome reliability in non-ambulatory boys/men with Duchenne muscular dystrophy.

Abstract: Background Therapeutic trials in Duchenne muscular dystrophy (DMD) often exclude non-ambulatory individuals. Here we establish optimal and reliable assessments in a multicenter trial.

Wallerian degeneration and recovery of motor nerves after multiple focused cold therapies

Abstract: Introduction: A device has been developed to apply freezing temperatures to temporarily impede nerve conduction, resulting in inhibition of voluntary skeletal muscle contraction. This device was designed as an alternative to the neurotoxins usually used to treat movement disorders. Methods: We evaluated the effects of single and 3 repeat treatments with a cryoprobe device (−55°C) on a sciatic nerve rat model. Long-term effects of repeated treatment were evaluated through assessments of physiological function and histological analysis. Results: There was consistent weakening of physiological function after each treatment, with recovery of normal function by 8 weeks posttreatment. Histological findings showed axonal degeneration with no disruption to the epineurial or perineurial structures. Progressive axonal regeneration was followed by normal recovery by 24 weeks post-treatment. Conclusions: Low-temperature treatment of motor nerves did not result in permanent or long-term changes to nerve function or structure. Muscle Nerve 51: 268–275, 2015

Bochum ultrasound score versus clinical and electrophysiological parameters in distinguishing acute‐onset chronic from acute inflammatory demyelinating polyneuropathy

Abstract: Introduction The aim of this study was to evaluate whether a nerve ultrasound score (Bochum ultrasound score, BUS), clinical, and electrophysiological parameters could distinguish subacute chronic (CIDP) from acute inflammatory demyelinating polyneuropathy (AIDP). Methods Phase 1: The charts of 35 patients with polyradiculoneuropathy were evaluated retrospectively regarding BUS, clinical, and electrophysiological parameters (A-waves, sural nerve sparing pattern, sensory ratio > 1). Phase 2: All parameters were evaluated prospectively in 10 patients with subacute polyradiculoneuropathy. Results Phase 1: A sum score of ≥2 points in BUS and the presence of sensory symptoms were significantly more frequent in the subacute CIDP group than in the AIDP group (P < 0.001).The electrophysiological parameters showed no significant changes between the 2 groups. Phase 2: BUS (83.3%; 100%;), sensory symptoms (100%; 75%), absence of autonomic nervous system dysfunction (83.3%; 75%), or bulbar palsy (83.3%; 50%) showed the best sensitivity and specificity in distinguishing subacute CIDP from AIDP. Conclusions BUS is a useful diagnostic tool for distinguishing subacute CIDP from AIDP. Muscle Nerve 51: 846–852, 2015

Peripheral nerve ultrasound in amyotrophic lateral sclerosis phenotypes

Abstract: Introduction: In this study we sought to determine the cross-sectional area (CSA) of peripheral nerves in patients with distinct subtypes of amyotrophic lateral sclerosis (ALS). Methods: Ulnar and median nerve ultrasound was performed in 78 ALS patients [classic, n=21; upper motor neuron dominant (UMND), n=14; lower motor neuron dominant (LMND), n=20; bulbar, n=15; primary lateral sclerosis (PLS), n=8] and 18 matched healthy controls. Results: Compared with controls, ALS patients had significant, distally pronounced reductions of ulnar CSA (forearm/wrist level) across all disease groups, except for PLS. Median nerve CSA (forearm/wrist level) did not differ between controls and ALS. Conclusion: Ulnar nerve ultrasound in ALS subgroups revealed significant differences in distal CSA values, which suggests it has value as a marker of LMN involvement. Its potential was particularly evident in the UMND and PLS groups, which can be hard to separate clinically, yet their accurate separation has major prognostic implications.

Quality of life in amyotrophic lateral sclerosis patients and caregivers: Impact of assistive communication from early stages.

Abstract: Introduction: In this study we performed a longitudinal investigation to assess the impact of early introduction of assistive communication devices (ACDs) on quality of life (QoL) in amyotrophic lateral sclerosis (ALS) patients and their caregivers. Methods: Patients were followed for 7–10 months (3 evaluation periods). Bulbar-onset ALS patients (N = 27) and paired caregivers (N = 17) were included. Fifteen randomly selected patients received early support in ACD use. Patients were assessed using the ALS Functional Rating Scale—revised (ALSFRS-R), the McGill QoL (MQoL), the Communication Effectiveness Index (CETI), and performance in writing; and caregivers were assessed with the MQoL and World Health Organization Quality of Life questionnaire (WHOQOL-BREF). Results: Patients with early support had higher MQoL Psychological and MQoL Existential well-being domains; caregivers had higher MQoL Support domain and their MQoL Psychological domain positively associated with patient CETI. Most patients could communicate using a touchscreen keyboard to write, even when handwriting and speech were not possible. Conclusion: Early intervention with an ACD seems to have a positive impact on QoL and gives patients the opportunity to improve skills for communication in later disease stages. Muscle Nerve, 2015

Neuromuscular deficits after peripheral joint injury: a neurophysiological hypothesis.

Abstract: In addition to biomechanical disturbances, peripheral joint injuries (PJIs) can also result in chronic neuromuscular alterations due in part to loss of mechanoreceptor-mediated afferent feedback. An emerging perspective is that PJI should be viewed as a neurophysiological dysfunction, not simply a local injury. Neurophysiological and neuroimaging studies have provided some evidence for central nervous system (CNS) reorganization at both the cortical and spinal levels after PJI. The novel hypothesis proposed is that CNS reorganization is the underlying mechanism for persisting neuromuscular deficits after injury, particularly muscle weakness. There is a lack of direct evidence to support this hypothesis, but future studies utilizing force-matching tasks with superimposed transcranial magnetic stimulation may be help clarify this notion.

Quantitative Muscle Ultrasound in Duchenne Muscular Dystrophy: A Comparison of Techniques

Abstract: Introduction Muscle pathology in Duchenne muscular dystrophy (DMD) can be quantified using ultrasound by measuring either the amplitudes of sound-waves scattered back from the tissue [quantitative backscatter analysis (QBA)] or by measuring these backscattered amplitudes after compression into grayscale levels (GSL) obtained from the images. Methods: We measured and compared QBA and GSL from 6 muscles of 25 boys with DMD and 25 healthy subjects, aged 2-14 years, with age and, in DMD, with function (North Star Ambulatory Assessment). Results: Both QBA and GSL were measured reliably (intraclass correlation ≥ 0.87) and were higher in DMD than controls (P < 0.0001). In DMD, average QBA and GSL measured from superficial regions of muscle increased (rho ≥ 0.47, P < 0.05) with both higher age and worse function; in contrast, GSL measured from whole regions of muscle did not. Conclusions: QBA and GSL measured from superficial regions of muscle can similarly quantify muscle pathology in DMD. Muscle Nerve 51: 207–213, 2015

Resistance strength training exercise in children with spinal muscular atrophy.

Abstract: Introduction Preliminary evidence in adults with spinal muscular atrophy (SMA) and in SMA animal models suggests exercise has potential benefits in improving or stabilizing muscle strength and motor function.

How electrodiagnosis predicts clinical outcome of focal peripheral nerve lesions.

Abstract: This article reviews the electrodiagnostic (EDX) prognostic factors for focal traumatic and nontraumatic peripheral nerve injuries. Referring physicians and patients often benefit from general and nerve-specific prognostic information from the EDX consultant. Knowing the probable outcome from a nerve injury allows the referring physician to choose the best treatment options for his/her patients. Nerve injuries are variable in their mechanism, location, and pathophysiology. The general effects of the injuries on nerve and muscle are well known, but more research is needed for nerve-specific information. Several factors currently known to influence prognosis include: nature of the nerve trauma, amount of axon loss, recruitment in muscles supplied by the nerve, the extent of demyelination, and the distance to reinnervate functional muscles. This article reviews these general concepts and also nerve-specific EDX measures that predict outcome after focal neuropathies.

Normative values for short-segment nerve conduction studies and ultrasonography of the ulnar nerve at the elbow.

Abstract: Introduction: In patients with ulnar neuropathy at the elbow (UNE), short-segment nerve conduction studies (NCS) are rarely performed due to unclear reference values. We excluded controls with subclinical UNE, calculated normative values, and tested them in UNE patients. Methods: Clinical examination, ultrasonography (US), and 2-cm short-segment ulnar motor NCS across the elbow were performed in 49 controls and 67 UNE patients. In controls, subclinical UNE was diagnosed if at least 2 studies were outside the reference limits in the same 2-cm segment. Results: Exclusion of controls with subclinical UNE produced less stringent normative values (2-cm conduction velocity: 25 to 31 m/s; US cross-sectional area: 11.6 to 9.6 mm2), which raised diagnostic sensitivity (short-segment NCS: 76% to 90%; 10-cm NCS: 72% to 85%, US: 43% to 79%). Conclusions: We propose the use of our normative values in patients with clinically definite and probable UNE after exclusion of alternative diagnoses. Muscle Nerve, 2015 Muscle Nerve 51: 370–377, 2015

Quantitative neuromuscular ultrasound in intensive care unit-acquired weakness: A systematic review.

Abstract: Intensive care unit–acquired weakness (ICU-AW) causes significant morbidity and impairment in critically ill patients. Recent advances in neuromuscular ultrasound (NMUS) allow evaluation of neuromuscular pathology early in critical illness. Here we review application of ultrasound in ICU-AW. MEDLINE-indexed articles were searched for terms relevant to ultrasound and critical illness. Two reviewers evaluated the resulting abstracts (n = 218) and completed full-text review (n = 13). Twelve studies and 1 case report were included. Ten studies evaluated muscle thickness or cross-sectional area (CSA): 8 reported a decrease, and 2 reported no change. Two studies reported preservation of muscle thickness in response to neuromuscular electrical stimulation, and 1 found no preservation. One study found decreases in gray-scale standard deviation, but no change in echogenicity. One study described increases in echogenicity and fasciculations. Ultrasound reliability in ICU-AW is not fully established. Further investigation is needed to identify ultrasound measures that reliably predict clinical, electrodiagnostic, and pathologic findings of ICU-AW. Muscle Nerve 52: 701–708, 2015