BACKGROUND AND PURPOSE:Critical illness polyneuropathy (CIP) has been linked to neurocardiac dysfunction mediated by autonomic nervous system dysregulation, which increases mortality. We aimed to assess if heart rate variability (HRV) biofeedback could improve neurocardiac function in CIP. METHODS:We randomly allocated (1:1) patients with electrophysiologically confirmed CIP undergoing early inpatient neurological rehabilitation to additional HRV or sham biofeedback over 14 days. We evaluated neurocardiac function via standard deviation of normal-to-normal intervals (SDNN) as the primary outcome, as well as HRV frequency domains, sympathetic cutaneous sudomotor and vasomotor functions and disability at baseline, post intervention and 4 weeks later. The study is registered on the German Clinical Trials Register (DRKS00028911). RESULTS:We included 30 patients with CIP (40% females, median [interquartile range] age 64.6 [56, 72] years). We observed an increase in SDNN and the predominantly parasympathetic high frequency domain post intervention (ß = 16.4, 95% confidence interval [CI] 0.2, 32.6 [p = 0.047] and ß = 1179.2, 95% CI 119.9, 2158.5 [p = 0.018]), which was sustained at the 4-week follow-up (ß = 25.7, 95% CI 6.0, 45.4 [p = 0.011] and ß = 25.7, 95% CI 6.0, 45.4 [p = 0.011]). Patients who underwent HRV biofeedback displayed a higher adjusted Barthel index, indicating less severe disability 4 weeks after the intervention compared to those in the sham group (ß = 23.3, 95% CI 5.5, 41.1 [p = 0.014]). Low frequency and sympathetic skin functions did not differ between groups (p = nonsignificant). CONCLUSIONS:Our study provides pilot data suggesting that, in patients with CIP, HRV biofeedback can improve neurocardiac function with a predominant effect on the parasympathetic nervous system and has a beneficial effect on functional recovery.

Background: Pleural effusion is characterized by excessive fluid collection in the pleural cavity. Black pleural effusion (BPE) is a rare entity with only limited scientific data. We aimed to review the current literature on black pleural effusion to characterize demographics, etiology, clinical presentation, pathological findings, available treatment strategies, and prognosis of this rare condition. Methods: We performed a systematic review of case reports and series and synthesized data on demographics, manifestations, management, and outcomes of patients with BPE. We searched Cochrane Library, PubMed, SCOPUS, and Google Scholar for any date until January 10, 2021. All studies (n = 31) that reported black pleural effusion in patients were added to the review. Prospective Register of Systematic Reviews registration number: CRD42020213839. Summary and descriptive analysis was performed on Jamovi version 1.2. Results: The mean age of 32 patients with BPE was 53 years, with male predominance (69%). The commonest risk factor was smoking (n = 9) followed by alcohol intake (n = 8). Dyspnea was the commonest symptom (n = 24, 75%). Pleural fluid was mostly exudative (n = 21). The commonest associated diagnosis was malignancy (n = 14), with 50% secondary to metastatic melanoma. The commonest intervention was therapeutic thoracocentesis (n = 25, 78%), and the effusion recurred in half of the cases where recurrence was reported (n = 13). In our review, we found the mortality rate to be at 20.8% (n = 20.8%). 58.3% of the patients were successfully treated and discharged home (n = 14). Conclusion: Although rare, BPE appears to be a relevant symptom as it seems to be frequently associated with modifiable risk factors and underlying malignancy. Our systematic review substantiates a vital research gap as observational research is imperative to characterize BPE further and form a basis for designing tailored diagnostic, preventive, and therapeutic strategies for BPE.

IntroductionAlcohol addiction compromises cardiovascular health, possibly due to impaired control of the heart and vasculature by the autonomic nervous system. We aimed to assess the effects of National Acupuncture Detoxification Association (NADA) acupuncture on cardiovascular autonomic functions, psychiatric comorbidities and abstinence in patients addicted to alcohol.Material and methodsA randomized sham controlled three-arm study was undertaken in 72 patients (nine females, aged 43.7 ± 9.2 years, mean ± SD) undergoing in-patient rehabilitation for alcohol addiction. Patients were randomly allocated (1:1:1) to receive twenty 30-minute NADA or sham acupuncture sessions within six weeks or no intervention. They were evaluated for craving, depression, anxiety and autonomic control of the heart (heart rate variability, HRV), vasculature (laser Doppler flowmetry) and sweat glands (sympathetic skin response). Testing was performed at baseline, immediately post intervention (sham intervention or control period, respectively) and another four weeks later. Abstinence was assessed one year after study completion.ResultsPatients in the NADA arm displayed increased HRV immediately post-intervention compared to baseline (SDNN: 72.8 ms ± 34.2 ms vs. 57.9 ms ± 31.2 ms, p = 0.001). This increase was sustained four weeks later (66.2 ms ± 32.4 ms, p = 0.015). HRV remained unaltered following sham or no acupuncture (p = n.s.). Autonomic function of vasculature and sweat glands, psychiatric comorbidities and one-year abstinence did not differ between study arms.ConclusionsNADA acupuncture may improve autonomic cardiac function. However, this improvement appears not to translate into alleviation of psychiatric comorbidities or sustained abstinence.

Polymyositis (PM) with cytochrome C oxidase negative fibers also referred to as PM with mitochondrial pathology (PM-Mito) is characterized by the symptoms of inclusion body myositis (IBM) and by the myopathological findings of PM except for an increase of muscle fibers with insufficient mitochondrial cytochrome C oxidase activity. Few PM-Mito cases are published; mitochondrial ultrastructure has not been studied in these patients. We report 2 PM-Mito patients with later onset than usually seen in IBM and poor responsiveness to glucocorticoids. Electron microscopy of muscle fibers showed irregular mitochondrial ultrastructure. Sjögren syndrome related antinuclear antibodies (Anti-Ro and Anti-La) were found in one of the two patients but the typical clinical symptoms of Sjögren syndrome such as xerostomia and keratoconjunctivitis were absent in this patient. Taken together, our observations, viewed in conjunction with the current literature, suggest that PM-Mito is an underdiagnosed disease with a multifactorial pathogenesis that should be elucidated in further studies. We want to encourage clinicians and pathologists to consider the possibility of PM-Mito in patients with atypical PM or sIBM.