Peripheral neuropathy, an independent risk factor for falls in the elderly, impairs stepping as a postural control mechanism: A case-cohort study.

BACKGROUND/AIMS: Peripheral neuropathies perturbate the sensorimotor system, causing difficulties in walking-related motor tasks and, eventually, falls. Falls result in functional dependency and reliance on healthcare, especially in older persons. We investigated if peripheral neuropathy is a genuine risk factor for falls in the elderly and if quantification of postural control via posturography is helpful in identifying subjects at risk of falls. METHODS: Seventeen older persons with a clinical polyneuropathic syndrome of the lower limbs and converging electrophysiology were compared with 14 older persons without polyneuropathy. All participants were characterized via quantitative motor and sensory testing, neuropsychological assessment, and self-questionnaires. Video-nystagmography and caloric test excluded vestibulocochlear dysfunction. For further analysis, all subjects were stratified into fallers and non-fallers. Overall, 28 patients underwent computerized dynamic posturography for individual fall risk assessment. Regression analyses were performed to identify risk factors and predictive posturography parameters. RESULTS: Neuropathy is an independent risk factor for falls in the elderly, while no differences were observed for age, gender, weight, frailty, DemTect test, timed "Up & Go" test, and dizziness-related handicap score. In computerized dynamic posturography, fallers stepped more often to regain postural control in challenging conditions, while the Rhythmic Weight Shift test showed a lack of anterior-posterior bidirectional voluntary control. INTERPRETATION: Our study confirms peripheral neuropathy as a risk factor for older persons' falls. Fallers frequently used stepping to regain postural control. The voluntary control of this coping movement was impaired. Further investigations into these parameters' value in predicting the risk of falls in the elderly are warranted.

Differential diagnosis of Guillain-Barré syndrome: steroid-responsive radiculopathy in Evans syndrome.

Guillain-Barré syndrome is the most common acute inflammatory demyelinating peripheral nerve condition. Occasionally, other autoimmune conditions can mimic Guillain-Barré syndrome but may require different diagnostic workup and treatment. We report here two patients with Evans syndrome, a rare hematological autoimmune condition who developed a subacute inflammatory radiculopathy. Similarities and distinguishing clinical and diagnostic features are discussed.

Tissue Doppler ultrasound of arm muscles to assess myotonia in myotonic dystrophies: An exploratory study.

INTRODUCTION/AIMS: Myotonia is a key symptom of myotonic dystrophies (DM), and its quantification is challenging. This exploratory study evaluated the utility of tissue Doppler ultrasound (TDU) to assess myotonia in DM. METHODS: Twelve DM patients (seven type-1 DM [DM1] and five type-2 DM [DM2]) and 20 age-matched healthy subjects were included in this cross-sectional study. After measuring cross-sectional areas of the flexor digitorum superficialis (FDS) and extensor digitorum communis (EDC) muscles in a resting state, muscle contraction/relaxation time, time to peak tissue velocity, peak tissue velocity and velocity gradients of these muscles were measured via TDU while performing forced fist unclenching after fist closure. Additionally, grip strength, Medical Research Council Sum score and patient-reported myotonia severity scores were assessed. RESULTS: DM1 and DM2 patients had a lower grip strength than healthy subjects (p = .0001/p = .002). Patient-reported myotonia did not differ between DM1 and DM2 patients. DM1 patients revealed FDS and EDC atrophy compared to DM2 patients and healthy subjects (p = .003/p = .004). TDU revealed prolonged muscle contraction and relaxation times in both DM subtypes, with prolonged time to reach FDS peak relaxation velocity and altered peak FDS relaxation velocity only in DM1 patients (p = .03/p = .003). Peak FDS relaxation velocity correlated inversely with C(C)TG repeat numbers in DM patients. Sensitivity of TDU parameters to detect myotonic dystrophy varied between 50% and 75%, with a specificity of 95%. DISCUSSION: Our exploratory study suggests that TDU could serve as a novel tool to quantify myotonia in DM patients, but larger follow-up studies are warranted to validate its diagnostic accuracy.

Preventive Effect of Neuromuscular Training on Chemotherapy-Induced Neuropathy: A Randomized Clinical Trial.

Importance: Chemotherapy-induced peripheral neuropathy (CIPN) is a highly prevalent and clinically relevant adverse effect of chemotherapy, negatively impacting patient quality of life. The lack of effective preventive or therapeutic options regarding CIPN often requires changes in cancer therapy, potentially resulting in reduced survival. Objective: To determine whether sensorimotor training (SMT) and whole-body vibration (WBV) training reduce symptoms and decrease the onset of CIPN. Design, Setting, and Participants: This prospective multicenter randomized clinical trial (STOP) followed up patients over 5 years at 4 centers in or near Cologne, Germany. Patients undergoing treatment with oxaliplatin or vinca alkaloids were recruited. Participants were recruited from May 2014 to November 2020. Data were last analyzed in June 2021. Interventions: Participants in the intervention groups performed supervised SMT or WBV training sessions twice a week, each lasting approximately 15 to 30 minutes, concomitant to medical therapy. Main Outcomes and Measures: The primary end point was the incidence of CIPN. Secondary end points included subjective neuropathy symptoms, balance control, physical activity levels, quality of life, and clinical outcome. For cross-stratum evaluations, the Mantel-Haenszel test (MH) was used, and within individual strata, Fisher exact test was used for analysis. Results: A total of 1605 patients were screened, and 1196 patients did not meet all inclusion criteria, with 251 further excluded or declining participation. A total of 158 patients (mean [SD] age, 49.1 [18.0-82.0] years; 93 [58.9%] male) were randomized into 1 of 3 groups: 55 (34.8%) in SMT, 53 (33.5%) in WBV, and 50 (31.6%) in treatment as usual (TAU). The incidence of CIPN in participants was significantly lower in both intervention groups compared to the control group (TAU): (SMT, 12 of 40 [30.0%; 95% CI, 17.9%-42.1%] and WBV, 14 of 34 [41.2%; 95% CI, 27.9%-54.5%] vs TAU, 24 of 34 [70.6%; 95% CI, 58.0%-83.2%]; P = .002 for intention to treat-MH). Patients receiving vinca alkaloids and performing SMT benefited the most. Results were more pronounced in a per-protocol analysis (>75% participation in the intervention) (SMT, 8 of 28 [28.6%; 95% CI, 16.6%-40.5%] and WBV, 9 of 24 [37.5%; 95% CI, 24.4%-50.5%] vs TAU, 22 of 30 [73.3%; 95% CI, 61.6%-85.6%]). Improvements in favor of SMT compared to TAU were found for balance control bipedal with eyes open; bipedal with eyes closed; monopedal, vibration sensitivity, sense of touch, lower leg strength, pain reduction, burning sensation, chemotherapy dose reductions, and mortality. Conclusion and Relevance: This randomized clinical trial provides initial evidence that neuromuscular training decreases the onset of CIPN. Trial Registration: German Clinical Trials Register: DRKS00006088.

[Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP)]. / Chronische inflammatorische demyelinisierende Polyradikuloneuropathie (CIDP).

Chronic inflammatory demyelinating polyneuropathy (CIDP) is the most common chronic autoimmune disease of the peripheral nervous system. It is often difficult to diagnose, but severaly therapeutic options are nowadays available to reduce neurological deficits and to improve the disease course. This article exemplifies the management of CIDP by a typical case study.

Antibiotics-Induced Intestinal Immunomodulation Attenuates Experimental Autoimmune Neuritis (EAN).

BACKGROUND: The composition of gut microbiota plays a pivotal role in priming the immune system and thus impacts autoimmune diseases. Data on the effects of gut bacteria eradication via systemic antibiotics on immune neuropathies are currently lacking. This study therefore assessed the effects of antibiotics-induced gut microbiota alterations on the severity of experimental autoimmune neuritis (EAN), a rat model of Guillain-Barré Syndrome (GBS). Myelin P0 peptide 180-199 (P0 180-199)-induced EAN severity was compared between adult Lewis rats (12 weeks old) that received drinking water with or without antibiotics (colistin, metronidazole, vancomycin) and healthy rats, beginning antibiotics treatment immediately after immunization (day 0), and continuing treatment for 14 consecutive days. Neuropathy severity was assessed via a modified clinical score, and then related to gut microbiota alterations observed after fecal 16S rRNA gene sequencing at baseline and after EAN induction. Effectors of gut mucosal and endoneurial immunity were assessed via immunostaining. EAN rats showed increased gut mucosal permeability alongside increased mucosal CD8+ T cells compared to healthy controls. Antibiotics treatment alleviated clinical EAN severity and reduced endoneurial T cell infiltration, decreased gut mucosal CD8+ T cells and increased gut bacteria that may be associated with anti-inflammatory mechanisms, like Lactobacillus or Parasutterella. Our findings point out a relation between gut mucosal immunity and the pathogenesis of EAN, and indicate that antibiotics-induced intestinal immunomodulation might be a therapeutic approach to alleviate autoimmunity in immune neuropathies. Further studies are warranted to evaluate the clinical transferability of these findings to patients with GBS.

CLUH maintains functional mitochondria and translation in motoneuronal axons and prevents peripheral neuropathy.

Transporting and translating mRNAs in axons is crucial for neuronal viability. Local synthesis of nuclear-encoded mitochondrial proteins protects long-lived axonal mitochondria from damage; however, the regulatory factors involved are largely unknown. We show that CLUH, which binds mRNAs encoding mitochondrial proteins, prevents peripheral neuropathy and motor deficits in the mouse. CLUH is enriched in the growth cone of developing spinal motoneurons and is required for their growth. The lack of CLUH affects the abundance of target mRNAs and the corresponding mitochondrial proteins more prominently in axons, leading to ATP deficits in the growth cone. CLUH interacts with ribosomal subunits, translation initiation, and ribosome recycling components and preserves axonal translation. Overexpression of the ribosome recycling factor ABCE1 rescues the mRNA and translation defects, as well as the growth cone size, in CLUH-deficient motoneurons. Thus, we demonstrate a role for CLUH in mitochondrial quality control and translational regulation in axons, which is essential for their development and long-term integrity and function.

[Expert recommendations for magnetic resonance imaging of muscle disorders]. / Expertenempfehlung zur Magnetresonanztomographie bei Muskelerkrankungen.

BACKGROUND: Magnetic resonance (MRI) imaging of the skeletal muscles (muscle MRI for short) is increasingly being used in clinical routine for diagnosis and longitudinal assessment of muscle disorders. However, cross-centre standards for measurement protocol and radiological assessment are still lacking. OBJECTIVES: The aim of this expert recommendation is to present standards for the application and interpretation of muscle MRI in hereditary and inflammatory muscle disorders. METHODS: This work was developed in collaboration between neurologists, neuroradiologists, radiologists, neuropaediatricians, neuroscientists and MR physicists from different university hospitals in Germany. The recommendations are based on expert knowledge and a focused literature search. RESULTS: The indications for muscle MRI are explained, including the detection and monitoring of structural tissue changes and oedema in the muscle, as well as the identification of a suitable biopsy site. Recommendations for the examination procedure and selection of appropriate MRI sequences are given. Finally, steps for a structured radiological assessment are presented. CONCLUSIONS: The present work provides concrete recommendations for the indication, implementation and interpretation of muscle MRI in muscle disorders. Furthermore, it provides a possible basis for the standardisation of the measurement protocols at all clinical centres in Germany.

[Expert recommendations for magnetic resonance imaging of muscle disorders]. / Expertenempfehlung zur Magnetresonanztomographie bei Muskelerkrankungen.

BACKGROUND: Magnetic resonance (MRI) imaging of the skeletal muscles (muscle MRI for short) is increasingly being used in clinical routine for diagnosis and longitudinal assessment of muscle disorders. However, cross-centre standards for measurement protocol and radiological assessment are still lacking. OBJECTIVES: The aim of this expert recommendation is to present standards for the application and interpretation of muscle MRI in hereditary and inflammatory muscle disorders. METHODS: This work was developed in collaboration between neurologists, neuroradiologists, radiologists, neuropaediatricians, neuroscientists and MR physicists from different university hospitals in Germany. The recommendations are based on expert knowledge and a focused literature search. RESULTS: The indications for muscle MRI are explained, including the detection and monitoring of structural tissue changes and oedema in the muscle, as well as the identification of a suitable biopsy site. Recommendations for the examination procedure and selection of appropriate MRI sequences are given. Finally, steps for a structured radiological assessment are presented. CONCLUSIONS: The present work provides concrete recommendations for the indication, implementation and interpretation of muscle MRI in muscle disorders. Furthermore, it provides a possible basis for the standardisation of the measurement protocols at all clinical centres in Germany.