Migraine aura discrimination using machine learning: an fMRI study during ictal and interictal periods.

Functional magnetic resonance imaging (fMRI) studies on migraine with aura are challenging due to the rarity of patients with triggered cases. This study optimized methodologies to explore differences in ictal and interictal spatiotemporal activation patterns based on visual stimuli using fMRI in two patients with unique aura triggers. Both patients underwent separate fMRI sessions during the ictal and interictal periods. The Gaussian Process Classifier (GPC) was used to differentiate these periods by employing a machine learning temporal embedding approach and spatiotemporal activation patterns based on visual stimuli. When restricted to visual and occipital regions, GPC had an improved performance, with accuracy rates for patients A and B of roughly 86-90% and 77-81%, respectively (p < 0.01). The algorithm effectively differentiated visual stimulation and rest periods and identified times when aura symptoms manifested, as evident from the varying predicted probabilities in the GPC models. These findings contribute to our understanding of the role of visual processing and brain activity patterns in migraine with aura and the significance of temporal embedding techniques in examining aura phenomena. This finding has implications for diagnostic tools and therapeutic techniques, especially for patients suffering from aura symptoms.

Impact of Loneliness on Training Gains with Heart Rate Variability Biofeedback in the Elderly: A Pilot Study.

The negative impact of loneliness on the health of the elderly is particularly noticeable because of the effects of central control on the autonomic nervous system. Such an impact can be assessed through heart rate variability (HRV) analysis and can be modified using HRV biofeedback training. This study aimed to investigate the impact of different levels of social interaction reported by the elderly on HRV before and after training with HRV biofeedback and after a follow-up period. The participants of this pilot study comprised 16 elderly people of both sexes with a mean age of 71.20 ± 4.92 years. The participants were divided into two groups, the loneliness group (N = 8) and the no-loneliness group (N = 8), based on a combination of both criteria: the institutionalization condition (institutionalized or not) and the score on the loneliness scale (high or low). All participants had their HRV components recorded at baseline, after 14 training sessions with HRV biofeedback (three times a week, 15 min each for 4.5 weeks), and after 4.5 weeks of follow-up without training. After HRV biofeedback training, HRV components increased in both groups. However, the gains lasted at follow-up only in the no-loneliness group. In conclusion, loneliness can influence the maintenance of HRV after interruption of training with HRV biofeedback in the elderly. HRV biofeedback training can be an innovative and effective tool for complementary treatment of elderly individuals, but its effects on lonely elderly individuals need to be further investigated.

Long-term benefits of heart rate variability biofeedback training in older adults with different levels of social interaction: a pilot study.

To test whether heart rate variability (HRV) biofeedback training benefits older adults with different social interaction levels. METHODS: 32 older adults (16 were institutionalized and 16 were not). Both groups received 14 sessions, 15 min, 3 times a week, with half of the individuals receiving HRV biofeedback training and the other half receiving control training. The following parameters were assessed immediately before and after training, and 4.5 weeks after the last session (follow-up period): aerobic conditioning, anthropometric data, emotional scores, and HRV components. RESULTS: Before the training, the institutionalized individuals had higher scores of loneliness (p < 0.01) and depression (p < 0.0001) and lower social touches (p < 0.0001), body mass (p = 0.04), and body fat percentage (p = 0.002) than the non-institutionalized individuals. HRV biofeedback improved symptoms of depression in both groups. HRV improved only in the non-institutionalized group, and loneliness only in the institutionalized group. Lastly, all changes persisted after the follow-up period. CONCLUSIONS: HRV biofeedback training was effective in improving symptoms of depression in older adults. Improvement of HRV and loneliness was dependent on the level of social interaction.

The digiti quinti sign in hemiplegic migraine: An fMRI study.

BACKGROUND AND PURPOSE: The digiti quinti sign (DQS) consists of a wider angle between the fourth and fifth fingers (ANG) indicative of subtle hemiparesis that has been found interictally in hemiplegic migraine (HM), suggesting a permanent subtle motor dysfunction. The aim of this study was to find a possible cortical origin for the DQS using blood oxygen level dependent (BOLD) functional (f) MRI. METHODS: Eight HM patients and 13 controls entered the cross-sectional study. We examined hand dominance, performed handgrip tests with dynamometry, documented the DQS graphically in two consecutive sessions, and used BOLD-fMRI during a motor task specifically designed to measure the evoked activation in the motor cortex (M1). The brain activation at the symptomatic side was compared with the contralateral hemisphere and with both correspondent hemispheres in controls. RESULTS: Subjects had a normal neurological examination, except for DQS in all HM patients. The activation amplitude (beta values) and the cluster extension (mm3 ) of the activation area in M1 was smaller at the affected side. Besides, the cluster extension correlated negatively with the disease time span. The ANG was wider bilaterally in patients and the fMRI signals were reduced in the patient's group. CONCLUSION: The DQS, a relevant clinical finding in HM, indicates a disrupted cortical activation.

Interactions between emotion and action in the brain.

A growing literature supports the existence of interactions between emotion and action in the brain, and the central participation of the anterior midcingulate cortex (aMCC) in this regard. In the present functional magnetic resonance imaging study, we sought to investigate the role of self-relevance during such interactions by varying the context in which threating pictures were presented (with guns pointed towards or away from the observer). Participants performed a simple visual detection task following exposure to such stimuli. Except for voxelwise tests, we adopted a Bayesian analysis framework which evaluated evidence for the hypotheses of interest, given the data, in a continuous fashion. Behaviorally, our results demonstrated a valence by context interaction such that there was a tendency of speeding up responses to targets after viewing threat pictures directed towards the participant. In the brain, interaction patterns that paralleled those observed behaviorally were observed most notably in the middle temporal gyrus, supplementary motor area, precentral gyrus, and anterior insula. In these regions, activity was overall greater during threat conditions relative to neutral ones, and this effect was enhanced in the directed towards context. A valence by context interaction was observed in the aMCC too, where we also observed a correlation (across participants) of evoked responses and reaction time data. Taken together, our study revealed the context-sensitive engagement of motor-related areas during emotional perception, thus supporting the idea that emotion and action interact in important ways in the brain.

Cortical Thickness and Episodic Memory Impairment in Systemic Lupus Erythematosus.

BACKGROUND AND PURPOSE: The purpose of this study was to investigate differences in brain cortical thickness of systemic lupus erythematosus (SLE) patients with and without episodic memory impairment and healthy controls. METHODS: We studied 51 patients divided in 2 groups (SLE with episodic memory deficit, n = 17; SLE without episodic memory deficit, n = 34) by the Rey Auditory Verbal Learning Test and 34 healthy controls. Groups were paired based on sex, age, education, Mini-Mental State Examination score, and accumulation of disease burden. Cortical thickness from magnetic resonance imaging scans was determined using the FreeSurfer software package. RESULTS: SLE patients with episodic memory deficits presented reduced cortical thickness in the left supramarginal cortex and superior temporal gyrus when compared to the control group and in the right superior frontal, caudal, and rostral middle frontal and precentral gyri when compared to the SLE group without episodic memory impairment considering time since diagnosis of SLE as covaried. There were no significant differences in the cortical thickness between the SLE without episodic memory and control groups. CONCLUSIONS: Different memory-related cortical regions thinning were found in the episodic memory deficit group when individually compared to the groups of patients without memory impairment and healthy controls.

Primary Motor Cortex Representation of Handgrip Muscles in Patients with Leprosy.

BACKGROUND: Leprosy is an endemic infectious disease caused by Mycobacterium leprae that predominantly attacks the skin and peripheral nerves, leading to progressive impairment of motor, sensory and autonomic function. Little is known about how this peripheral neuropathy affects corticospinal excitability of handgrip muscles. Our purpose was to explore the motor cortex organization after progressive peripheral nerve injury and upper-limb dysfunction induced by leprosy using noninvasive transcranial magnetic stimulation (TMS). METHODS: In a cross-sectional study design, we mapped bilaterally in the primary motor cortex (M1) the representations of the hand flexor digitorum superficialis (FDS), as well as of the intrinsic hand muscles abductor pollicis brevis (APB), first dorsal interosseous (FDI) and abductor digiti minimi (ADM). All participants underwent clinical assessment, handgrip dynamometry and motor and sensory nerve conduction exams 30 days before mapping. Wilcoxon signed rank and Mann-Whitney tests were performed with an alpha-value of p<0.05. FINDINGS: Dynamometry performance of the patients' most affected hand (MAH), was worse than that of the less affected hand (LAH) and of healthy controls participants (p = 0.031), confirming handgrip impairment. Motor threshold (MT) of the FDS muscle was higher in both hemispheres in patients as compared to controls, and lower in the hemisphere contralateral to the MAH when compared to that of the LAH. Moreover, motor evoked potential (MEP) amplitudes collected in the FDS of the MAH were higher in comparison to those of controls. Strikingly, MEPs in the intrinsic hand muscle FDI had lower amplitudes in the hemisphere contralateral to MAH as compared to those of the LAH and the control group. Taken together, these results are suggestive of a more robust representation of an extrinsic hand flexor and impaired intrinsic hand muscle function in the hemisphere contralateral to the MAH due to leprosy. CONCLUSION: Decreased sensory-motor function induced by leprosy affects handgrip muscle representation in M1.

Clinical feasibility of Açai (Euterpe olerácea) pulp as an oral contrast agent for magnetic resonance cholangiopancreatography.

BACKGROUND: We evaluate the effectiveness of the Amazonian fruit pulp from Euterpe olerácea (popularly named Açaí) as a negative oral contrast agent applied to clinical routine. The use of such contrasts is particularly important in magnetic resonance cholangiopancreatography (MRCP) to reduce overlapping. MATERIALS AND METHODS: We administered Açaí pulp to 5 nonsymptomatic subjects and 35 patients submitted to unspecific abdominal MR imaging, intending to set up optimal protocol. In 8 MRCP examinations, contrast and image effects were assessed and graded blindly by 2 independent radiologists. Quantitative analysis was performed by Wilcoxon test as to verify the potential of the Açaí to eliminate overlap signal over the pancreaticobiliary tract. Adverse effects and subject tolerance were also addressed. RESULTS: The Açaí pulp elicited a local brightness decrease in T2-weighted images. The depiction of gallbladder, common bile duct, ampulla of Vater, and pancreatic duct was markedly improved after Açaí ingestion because of the suppression of the overlapping from bowel loops and gastric content (P < 0.01). All patients considered Açaí palatable, and no side effect was registered. CONCLUSIONS: The Açaí pulp can be used routinely in MRCP studies as a natural, safe, and inexpensive negative oral contrast agent with high efficacy and patient acceptance.