Electrodiagnostics and clinical correlates in acquired polyneuropathies

Peripheral neuropathy: A neglected cause of disability in COPD - A narrative review

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory syndrome with systemic involvement leading to various cardiovascular, metabolic, and neurological comorbidities. It is well known that conditions associated with oxygen deprivation and metabolic disturbance are associated with polyneuropathy, but current data regarding the relationship between COPD and peripheral nervous system pathology is limited. This review summarizes the available data on the association between COPD and polyneuropathy, including possible pathophysiological mechanisms such as the role of hypoxia, proinflammatory state, and smoking in nerve damage; the role of cardiovascular and metabolic comorbidities, as well as the diagnostic methods and screening tools for identifying polyneuropathy. Furthermore, it outlines the available options for managing and preventing polyneuropathy in COPD patients. Overall, current data suggest that optimal screening strategies to diagnose polyneuropathy early should be implemented in COPD patients due to their relatively common association and the additional burden of polyneuropathy on quality of life.

Immune Axonal Neuropathies Associated With Systemic Autoimmune Rheumatic Diseases

Immune axonal neuropathies are a particular group of immune-mediated neuropathies that occasionally accompany systemic autoimmune rheumatic diseases such as connective tissue dissorders and primary systemic vasculitides. Apart from vasculitis of vasa nervorum, various other mechanisms are involved in their pathogenesis, with possible therapeutic implications. Immune axonal neuropathies have highly heterogeneous clinical presentation and course, ranging from mild chronic distal sensorimotor polyneuropathy to severe subacute mononeuritis multiplex with rapid progression and constitutional symptoms such as fever, malaise, weight loss and night sweats, underpinning a vasculitic process. Sensory neuronopathy (ganglionopathy), small fiber neuropathy (sensory and/or autonomic), axonal variants of Guillain-Barré syndrome and cranial neuropathies have also been reported. In contrast to demyelinating neuropathies, immune axonal neuropathies show absent or reduced nerve amplitudes with normal latencies and conduction velocities on nerve conduction studies. Diagnosis and initiation of treatment are often delayed, leading to accumulating disability. Considering the lack of validated diagnostic criteria and evidence-based treatment protocols for immune axonal neuropathies, this review offers a comprehensive perspective on etiopathogenesis, clinical and paraclinical findings as well as therapy guidance for assisting the clinician in approaching these patients. High quality clinical research is required in order to provide indications and follow up rules for treatment in immune axonal neuropathies related to systemic autoimmune rheumatic diseases.

Characteristics of muscle cramps in patients with polyneuropathy

Muscle cramps are common in the general population and can be disabling for patients, but there is little evidence comprehensively evaluating cramp characteristics in patients with polyneuropathy. This study describes the prevalence and characteristics of muscle cramps in this patient group. Patients over 18 diagnosed with polyneuropathy were invited to join the study. Patients completed nerve conduction studies, the Toronto Clinical Neuropathy score, neuropathy-specific Vickrey's Quality of Life Assessment and a self-administered questionnaire examining demographics, neuropathy symptoms and cramp characteristics. Two hundred and twenty-five participants were enrolled (28.0% female). Sixty-three percent of patients experienced cramps, occurring on average 6 times per week, lasting 10.5 min and scoring 6 out of 10 on a pain scale and described as disabling by 43.6% of patients. No significant difference was found in cramp prevalence according to underlying pathophysiology (p = 0.52) or fiber type (p = 0.41). Patients with disabling cramps rated their physical (p < 0.0001) and mental (p = 0.04) quality of life lower than patients without disabling cramps. This study confirms that muscle cramps are common, disabling and associated with reduced quality of life in patients with polyneuropathy. Similar prevalence of cramps across predominant nerve fiber type suggests a role of sensory afferents in cramp generation, although this needs to be confirmed in larger cohorts.