Autonomic changes in Huntington's disease correlate with altered central autonomic network connectivity.

Autonomic dysfunction has been described in patients with Huntington's disease, but it is unclear if these changes in autonomic tone are related to the central autonomic network. We performed a pilot study to investigate the relationship between the integrity of the central autonomic network and peripheral manifestiations of autonomic dysfunction in premanifest Huntington's disease. We recruited male participants with pre-motor-manifest Huntington's disease and a comparison group consisting of healthy, male participants of approximately the same age. As this was a pilot study, only males were included to reduce confounding. Participants underwent a resting-state functional magnetic resonance imaging study to quantify functional connectivity within the central autonomic network, as well as a resting 3-lead ECG to measure heart rate variability with a particular focus on the parasympathetic time-domain measures of root mean square of successive differences between normal heartbeats. The pre-motor-manifest Huntington's disease participants had significantly decreased root mean square of successive differences between normal heartbeats values compared with the healthy comparison group. The pre-motor-manifest Huntington's disease group had significantly lower functional connectivity within the central autonomic network, which was positively correlated with root mean square of successive differences between normal heartbeats. Patients with pre-motor-manifest Huntington's disease have reduced functional connectivity within the central autonomic network, which is significantly associated with observed changes in autonomic function.

Behavioral and Emotional Dyscontrol Following Traumatic Brain Injury: A Systematic Review of Neuroimaging and Electrophysiological Correlates.

BACKGROUND: Behavioral and emotional dyscontrol commonly occur following traumatic brain injury (TBI). Neuroimaging and electrophysiological correlates of dyscontrol have not been systematically summarized in the literature to date. OBJECTIVE: To complete a systematic review of the literature examining neuroimaging and electrophysiological findings related to behavioral and emotional dyscontrol due to TBI. METHODS: A Preferred Reporting Items for Systematic Reviews and Meta-Analyses-compliant literature search was conducted in PubMed (MEDLINE), PsycINFO, EMBASE, and Scopus databases prior to May 2019. The database query yielded 4392 unique articles. These articles were narrowed based on specific inclusion criteria (e.g., clear TBI definition, statistical analysis of the relationship between neuroimaging and dyscontrol). RESULTS: A final cohort of 24 articles resulted, comprising findings from 1552 patients with TBI. Studies included civilian (n = 12), military (n = 10), and sport (n = 2) samples with significant variation in the severity of TBI incorporated. Global and region-based structural imaging was more frequently used to study dyscontrol than functional imaging or diffusion tensor imaging. The prefrontal cortex was the most common neuroanatomical region associated with behavioral and emotional dyscontrol, followed by other frontal and temporal lobe findings. CONCLUSIONS: Frontal and temporal lesions are most strongly implicated in the development of postinjury dyscontrol symptoms although they are also the most frequently investigated regions of the brain for these symptom categories. Future studies can make valuable contributions to the field by (1) emphasizing consistent definitions of behavioral and emotional dyscontrol, (2) assessing premorbid dyscontrol symptoms in subjects, (3) utilizing functional or structural connectivity-based imaging techniques, or (4) restricting analyses to more focused brain regions.

Response to TMS treatment for depression associated with higher levels of psychological well-being.

Treatment resistant depression (TRD) is a complex condition associated with a great deal of disability and suffering. The relationship between TRD and psychological well-being (PWB) appears to be more complex than a simple antithesis. Transcranial magnetic stimulation (TMS) is a well-tolerated treatment for TRD. However successful, a drawback for TMS is that it has a lack of predictive biomarkers for treatment response. Our study focuses on the relationship between PWB and treatment resistant depression, and how PWB relates to TMS treatment response. We hypothesized that TMS treatment responders would have higher levels of PWB at baseline. In this study of 21 patients with TRD, we used the Ryff Scales of Psychological Well-Being and Patient Health Questionnaire-9 (PHQ-9). We found a significant relationship between environmental mastery, purpose in life, self-acceptance, and total PWB with baseline depression but no significant correlation between autonomy, personal growth, and positive relations with others and baseline PHQ-9 scores. No Ryff domain of PWB significantly predicted change in PHQ-9 score. Interestingly, however, we found that TMS responders had higher levels of autonomy (M(SD) = 62.10(10.46), p = 0.022) and personal growth (M(SD) = 65.00(11.04), p = 0.007) than non-responders at baseline. These specific aspects of well-being appear to be distinct from depression and particularly important in treatment response. This discovery suggests that assessing PWB might prove clinically useful when assessing future candidates for TMS treatment of TRD. Further research is necessary to evaluate the effects of TMS on PWB since these may be distinct from its effect on depression symptomology.

Reliability of targeting methods in TMS for depression: Beam F3 vs. 5.5 cm.

BACKGROUND: No consensus exists in the clinical transcranial magnetic stimulation (TMS) field as to the best method for targeting the left dorsolateral prefrontal cortex (DLPFC) for depression treatment. Two common targeting methods are the Beam F3 method and the 5.5 cm rule. OBJECTIVE: Evaluate the anatomical reliability of technician-identified DLPFC targets and obtain consensus average brain and scalp MNI152 coordinates. METHODS: Three trained TMS technicians performed repeated targeting using both the Beam F3 method and 5.5 cm rule in ten healthy subjects (n = 162). Average target locations were plotted on 7T structural MRIs to compare inter- and intra-rater reliability, respectively. RESULTS: (1) Beam F3 inter- and intra-rater reliability was superior to 5.5 cm targeting (p = 0.0005 and 0.0035). (2) The average Beam F3 location was 2.6±1.0 cm anterolateral to the 5.5 cm method. CONCLUSIONS: Beam F3 targeting demonstrates greater precision and reliability than the 5.5 cm method and identifies a different anatomical target.

A new device to improve target localization for transcranial magnetic stimulation therapy.

BACKGROUND: Accurate identification of cranial midline structures is essential for many targeting techniques that use repetitive transcranial magnetic stimulation (rTMS), including the Beam F3 method used for depression treatment. OBJECTIVE: Evaluate whether a novel, laser-sighted device will assist with more accurate identification of the cranial midline relative to standard scalp-based measurement procedures. METHODS: Three trained TMS technicians performed repeated scalp-based measurements to identify the inion and vertex on five subjects (n = 54 measurements). Measurements were compared to points identified with the midline localizer device and the true midline as defined by MRI midline structures. RESULTS: Use of the midline localizer was more accurate for midline identification than technician measurement (p = 0.00025) and the ratio of localizing the midline within 5 mm was higher (78% versus 54%, p = 0.008). CONCLUSION: Use of a laser-sighted midline localizer device can improve the accuracy of scalp measurements associated with target localization for rTMS treatment protocols.