Preliminary evidence of transcutaneous vagus nerve stimulation effects on sleep in veterans with post-traumatic stress disorder.

Sleep problems are common among veterans with post-traumatic stress disorder and closely associated with hyperarousal symptoms. Transcutaneous vagus nerve stimulation (tVNS) may have potential to improve sleep quality in veterans with PTSD through effects on brain systems relevant to hyperarousal and sleep-wake regulation. The current pilot study examines the effect of 1 h of tVNS administered at "lights out" on sleep architecture, microstructure, and autonomic activity. Thirteen veterans with PTSD completed two nights of laboratory-based polysomnography during which they received 1 h of either active tVNS (tragus) or sham stimulation (earlobe) at "lights out" with randomised order. Sleep staging and stability metrics were derived from polysomnography data. Autonomic activity during sleep was assessed using the Porges-Bohrer method for calculating respiratory sinus arrhythmia (RSAP-B ). Paired t-tests revealed a small decrease in the total sleep time (d = -0.31), increase in N3 sleep (d = 0.23), and a small-to-moderate decrease in REM sleep (d = -0.48) on nights of active tVNS relative to sham stimulation. tVNS was also associated with a moderate reduction in cyclic alternating pattern (CAP) rate (d = -0.65) and small-to-moderate increase in RSAP-B during NREM sleep. Greater NREM RSAP-B was associated with a reduced CAP rate and NREM alpha power. This pilot study provides preliminary evidence that tVNS may improve sleep depth and stability in veterans with PTSD, as well as increase parasympathetically mediated nocturnal autonomic activity. These results warrant continued investigation into tVNS as a potential tool for treating sleep disturbance in veterans with PTSD.

Hypersensitivity Pneumonitis With and Without Autoimmune Features: A Clinical Comparative Analysis.

BACKGROUND: Hypersensitivity pneumonitis (HP) is an interstitial lung disease (ILD) caused by an immunological reaction to repeated inhalational exposure to antigens. The etiology and exact immunopathology are poorly understood. Autoimmunity overlapping with HP has been described but the role of concomitant autoimmunity in the clinical course and outcome of the HP is not clearly established. In this study, we examined patients diagnosed with HP and compare them to patients with concomitant HP and autoimmunity. METHODS: Patients were retrospectively screened from a single-center ILD registry. Patients > 18 years with an established multidisciplinary diagnosis of HP were included in the study. Patients with HP without autoimmune features and patients with HP with autoimmune features (HPAF) were assessed. We compared the demographics, clinical characteristics, treatment, and outcomes between the two groups. We used a Cox proportional hazards model to compare lung transplant-free survival outcomes of patients with HPAF to those with non-HPAF HP patients. RESULTS: Of 73 patients with HP, 43 were diagnosed with HPAF. Patients with HPAF had a higher echocardiographic probability of pulmonary hypertension as compared to non-HPAF HP patients [48.8 vs 23.3%, p = 0.028, Crude odds ratio (cOR) = 3.14]. Symptomatically, those with HPAF reported a higher prevalence of arthritis as compared to non-HPAF HP (20.9 vs 3.3%, p = 0.040, cOR = 7.68). No significant differences between pulmonary function tests, oxygen requirements, mortality, and lung transplantation rates were found between the two groups. There was no statistically significant difference in transplant-free survival (p = 0.836). CONCLUSION: Patients with HPAF had a higher echocardiographic probability of pulmonary hypertension as compared to patients with non-HPAF HP. The clinical characteristics and outcomes did not differ between the two groups and concomitant autoimmunity among the HP group did not portend a poorer prognosis.

Posttraumatic Stress Disorder Subsequent to Apparent Mild Traumatic Brain Injury.

Posttraumatic stress disorder (PTSD) is prevalent among veterans with a history of traumatic brain injury (TBI); however, the relationship between TBI and PTSD is not well understood. We present the case of a 31-year-old male veteran with PTSD who reported TBI before entering the military. The reported injury appeared to be mild: He was struck on the head by a baseball, losing consciousness for ∼10 seconds. Years later, he developed severe PTSD after combat exposure. He was not receiving clinical services for these issues but was encountered in the context of a research study. We conducted cognitive, autonomic, and MRI assessments to assess brain function, structure, and neurophysiology. Next, we compared amygdala volume, uncinate fasciculus diffusion, functional connectivity, facial affect recognition, and baroreceptor coherence with those of a control group of combat veterans (n = 23). Our veteran's MRI revealed a large right medial-orbital prefrontal lesion with surrounding atrophy, which the study neuroradiologist interpreted as likely caused by traumatic injury. Comparison with controls indicated disrupted structural and functional connectivity of prefrontal-limbic structures and impaired emotional, cognitive, and autonomic responses. Detection of this injury before combat would have been unlikely in a clinical context because our veteran had reported a phenomenologically mild injury, and PTSD is a simple explanation for substance abuse, sleep impairment, and psychosocial distress. However, it may be that right prefrontal-limbic disruption imparted vulnerability for the development of PTSD and exacerbated our veteran's emotional response to, and recovery from, PTSD.