Internally vs. externally triggered movements in patients with major depression

Digital clock drawing test metrics in older patients before and after endoscopy with sedation: An exploratory analysis

BACKGROUND

In the postoperative period, clinically feasible instruments to monitor elderly patients' neurocognitive recovery and discharge-readiness, especially after short-stay procedures, are limited. Cognitive monitoring may be improved by a novel digital clock drawing test (dCDT). We screened for cognitive impairment with the 4 A Test (4AT) and then administered the dCDT pre and post short-stay procedure (endoscopy). The primary aim was to investigate whether the dCDT was sensitive to a change in cognitive status postendoscopy. We also investigated if preoperative cognitive status impacted postendoscopy dCDT variables.

METHODS

We recruited 100 patients ≥65 years presenting for endoscopy day procedures at a single metropolitan hospital. Participants were assessed after admission and immediately before discharge from the hospital. We administered the 4AT, followed by both command and copy clock conditions of the dCDT. We analysed the total drawing time (dCDT time), as well as scored the drawn clock against the established Montreal Cognitive Assessment (MoCA) criteria both before and after endoscopy.

RESULTS

Linear regression showed higher 4AT test scores (poorer performance) were associated with longer postoperative dCDT time (β = 5.6, p = 0.012) for the command condition after adjusting for preoperative baseline dCDT metrics, sex, age, and years of education.

CONCLUSION

Postoperative dCDT time-based variables slowed in those with baseline cognitive impairment detected by the 4AT, but not for those without cognitive impairment. Our results suggest the dCDT, using the command mode, may help detect cognitive impairment in patients aged >65 years after elective endoscopy.

Functional connectivity of supplementary motor area during finger-tapping in major depression

Psychomotor disturbance has been consistently regarded as an essential feature of depressive disorders. Studying objectively measurable motor behaviors like finger-tapping may help advance the diagnostic methods. Twenty-five patients with major depressive disorder (MDD) and 15 healthy participants underwent functional magnetic resonance imaging (fMRI) measurements while tapping their index fingers. The finger-tapping (FT) task was performed by the right hand (the tapping frequency varied between 1, 2 and 4 Hz) or both hands either in synchrony or alternation (the tapping frequency varied between 1 and 2 Hz). A mixed-model ANOVA was used for between- and within-group comparisons of the task accuracy and fMRI percent signal change in the supplementary motor area (SMA) during 26-second sequences of finger-tapping. Furthermore, using seed-based correlation analyses we compared the connectivity of the SMA between the two samples. At the behavioral level, no significant group differences in FT performance between the patient and control groups was observed. The mean fMRI percent signal change of the SMA was significantly elevated at higher levels of speed in both groups. In the MDD group, an increased connectivity of the left SMA with the bilateral cortical and cerebellar motor- and vision-related regions was found. Most importantly, a decreased connectivity between the SMA and the basal ganglia was found at frequencies of 4 Hz. Our findings support the contention that, in depression, brain connectivity measures during motor performance may reveal deviant neural processes that are potentially relevant to measurable (bio)markers for individual diagnosis and treatment.

Field Application of Digital Technologies for Health Assessment in the 10,000 Families Study

BACKGROUND

We field tested new-to-market portable, digital applications to assess hearing, pulmonary, and cognitive function to determine the feasibility of implementing these applications across a range of age groups in the pilot phase of the 10,000 Families Study (10KFS), a new Minnesota family-based prospective cohort study.

METHODS

We followed manufacturer recommended protocols for audiometry (SHOEBOX Inc), spirometry (NuvoAir), and the digital clock drawing test (dCDT; Digital Cognition Technologies Inc).

RESULTS

These digital devices were low cost and readily implemented in a 2.5-hour health fair visit with minimal training (2-3 hours) of study staff. To date, we have performed these measurements on 197 eligible 10KFS participants during an in-person clinic visit. A total of 37 children (age 4-17 years), 107 adults (18-64 years), and 53 seniors (≥65 years) were eligible to undergo hearing and pulmonary assessments. Children were less likely to successfully complete the hearing test (76%) compared with adults (86%) and seniors (89%). However, successful completion of the pulmonary assessment was high across all groups: 100% of children and seniors and 98% of adults. The dCDT was performed among those over the age of 40, and completion rates were 92% for those aged 41-64 and 94% for those ≥65 years.

CONCLUSIONS

Our field testing indicates these digital applications are easy and cost-effective to implement in epidemiologic studies.

IMPACT

Digital applications provide exciting opportunities to collect data in population studies. Issues related to data privacy, data access, and reproducibility of measurements need to be addressed before deploying digital applications in epidemiologic studies.See all articles in this CEBP Focus section, "Modernizing Population Science."

Evaluating the severity of depressive symptoms using upper body motion captured by RGB-depth sensors and machine learning in a clinical interview setting: A preliminary study

BACKGROUND

Mood disorders have long been known to affect motor function. While methods to objectively assess such symptoms have been used in experiments, those same methods have not yet been applied in clinical practice because the methods are time-consuming, labor-intensive, or invasive.

METHODS

We videotaped the upper body of each subject using a Red-Green-Blue-Depth (RGB-D) sensor during a clinical interview setting. We then examined the relationship between depressive symptoms and body motion by comparing the head motion of patients with major depressive disorders (MDD) and bipolar disorders (BD) to the motion of healthy controls (HC). Furthermore, we attempted to predict the severity of depressive symptoms by using machine learning.

RESULTS

A total of 47 participants (HC, n = 16; MDD, n = 17; BD, n = 14) participated in the study, contributing to 144 data sets. It was found that patients with depression move significantly slower compared to HC in the 5th percentile and 50th percentile of motion speed. In addition, Hamilton Depression Rating Scale (HAMD)-17 scores correlated with 5th percentile, 50th percentile, and mean speed of motion. Moreover, using machine learning, the presence and/or severity of depressive symptoms based on HAMD-17 scores were distinguished by a kappa coefficient of 0.37 to 0.43.

LIMITATIONS

Limitations include the small number of subjects, especially the number of severe cases and young people.

CONCLUSIONS

The RGB-D sensor captured some differences in upper body motion between depressed patients and controls. If much larger samples are accumulated, machine learning may be useful in identifying objective measures for depression in the future.

Correlations Between Personality and Brain Structure: A Crucial Role of Gender

Previous studies have shown that males and females differ in personality and gender differences have also been reported in brain structure. However, effects of gender on this "personality-brain" relationship are yet unknown. We therefore investigated if the neural correlates of personality differ between males and females. Whole brain voxel-based morphometry was used to investigate the influence of gender on associations between NEO FFI personality traits and gray matter volume (GMV) in a matched sample of 182 males and 182 females. In order to assess associations independent of and dependent on gender, personality-GMV relationships were tested across the entire sample and separately for males and females. There were no significant correlations between any personality scale and GMV in the analyses across the entire sample. In contrast, significant associations with GMV were detected for neuroticism, extraversion, and conscientiousness only in males. Interestingly, GMV in left precuneus/parieto-occipital sulcus correlated with all 3 traits. Thus, our results indicate that brain structure-personality relationships are highly dependent on gender, which might be attributable to hormonal interplays or differences in brain organization between males and females. Our results thus provide possible neural substrates of personality-behavior relationships and underline the important role of gender in these associations.

Network connectivity of motor control in the ageing brain

Older individuals typically display stronger regional brain activity than younger subjects during motor performance. However, knowledge regarding age-related changes of motor network interactions between brain regions remains scarce. We here investigated the impact of ageing on the interaction of cortical areas during movement selection and initiation using dynamic causal modelling (DCM). We found that age-related psychomotor slowing was accompanied by increases in both regional activity and effective connectivity, especially for ‘core’ motor coupling targeting primary motor cortex (M1). Interestingly, younger participants within the older group showed strongest connectivity targeting M1, which steadily decreased with advancing age. Conversely, prefrontal influences on the motor system increased with advancing age, and were inversely correlated with reduced parietal influences and core motor coupling. Interestingly, higher net coupling within the prefrontal-premotor-M1 axis predicted faster psychomotor speed in ageing. Hence, as opposed to a uniform age-related decline, our findings are compatible with the idea of different age-related compensatory mechanisms, with an important role of the prefrontal cortex compensating for reduced coupling within the core motor network.

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Enhanced motor network activity and connectivity in ageing

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Parietal-premotor and premotor-M1 coupling decreases with advancing age.

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Prefrontal influences on the motor system increase with advancing age.

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Prefrontal cortex compensates for age-related decline in other motor connections.

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Prefrontal-premotor-M1 coupling predicts psychomotor speed in ageing.

Revisiting the Syndrome of "Obsessional Slowness"

Background

Obsessional slowness (OS) denotes a rare condition of disablingly slow motor performance. It was originally described in patients with obsessive-compulsive disorder as a "primary" condition; however, subsequent reports have included heterogeneous clinical populations. We wished to reassess patients with this diagnosis at our own institution and also revisit the literature to provide an overview of this condition.

Methods

Clinical documentation and videos of 3 patients diagnosed with OS in the National Hospital for Neurology and Neurosurgery (London, UK) were reviewed. One of the patients was clinically reappraised. A systematic review of published articles with sufficient clinical patient information was also conducted.

Results

Our 3 cases were male with symptom onset in adolescence or early adulthood. Motor slowness with poverty of movement and a history of obsessive-compulsive symptoms were characteristic. Poor speech production, bizarre postures, mannerisms, echophenomena, and oculogyric tics were also noted. Dopaminergic imaging was normal in 2 cases. One case had autistic features. Systematic literature review identified 77 further cases. Male preponderance with symptom onset mainly during the second decade and presence of obsessive-compulsive symptoms were noted. Additional motor and neuropsychiatric features were often present.

Conclusion

The existence of OS as a "primary" condition is doubtful. This diagnosis has been given to characterize different clinical presentations ranging from obsessive-compulsive disorder with motor slowness resulting from covert obsessive-compulsive symptoms to catatonia. Clinicians should be aware of this syndrome to separate it from juvenile parkinsonism and other causes of motor slowness given that diagnostic approaches and treatment strategies differ.

Audiovisual emotional processing and neurocognitive functioning in patients with depression

Alterations in the processing of emotional stimuli (e.g., facial expressions, prosody, music) have repeatedly been reported in patients with major depression. Such impairments may result from the likewise prevalent executive deficits in these patients. However, studies investigating this relationship are rare. Moreover, most studies to date have only assessed impairments in unimodal emotional processing, whereas in real life, emotions are primarily conveyed through more than just one sensory channel. The current study therefore aimed at investigating multi-modal emotional processing in patients with depression and to assess the relationship between emotional and neurocognitive impairments. Fourty one patients suffering from major depression and 41 never-depressed healthy controls participated in an audiovisual (faces-sounds) emotional integration paradigm as well as a neurocognitive test battery. Our results showed that depressed patients were specifically impaired in the processing of positive auditory stimuli as they rated faces significantly more fearful when presented with happy than with neutral sounds. Such an effect was absent in controls. Findings in emotional processing in patients did not correlate with Beck's depression inventory score. Furthermore, neurocognitive findings revealed significant group differences for two of the tests. The effects found in audiovisual emotional processing, however, did not correlate with performance in the neurocognitive tests. In summary, our results underline the diversity of impairments going along with depression and indicate that deficits found for unimodal emotional processing cannot trivially be generalized to deficits in a multi-modal setting. The mechanisms of impairments therefore might be far more complex than previously thought. Our findings furthermore contradict the assumption that emotional processing deficits in major depression are associated with impaired attention or inhibitory functioning.

Motor imagery in unipolar major depression

Background: Motor imagery is a potential tool to investigate action representation, as it can provide insights into the processes of action planning and preparation. Recent studies suggest that depressed patients present specific impairment in mental rotation. The present study was designed to investigate the influence of unipolar depression on motor imagery ability.

Methods: Fourteen right-handed patients meeting DSM-IV criteria for unipolar depression were compared to 14 matched healthy controls. Imagery ability was accessed by the timing correspondence between executed and imagined movements during a pointing task, involving strong spatiotemporal constraints (speed/accuracy trade-off paradigm).

Results: Compared to controls, depressed patients showed marked motor slowing on both actual and imagined movements. Furthermore, we observed greater temporal discrepancies between actual and mental movements in depressed patients than in healthy controls. Lastly, depressed patients modulated, to some extent, mental movement durations according to the difficulty of the task, but this modulation was not as strong as that of healthy subjects.

Conclusion: These results suggest that unipolar depression significantly affects the higher stages of action planning and point out a selective decline of motor prediction.

Digital Clock Drawing: differentiating "thinking" versus "doing" in younger and older adults with depression

Psychomotor slowing has been documented in depression. The digital Clock Drawing Test (dCDT) provides: (i) a novel technique to assess both cognitive and motor aspects of psychomotor speed within the same task and (ii) the potential to uncover subtleties of behavior not previously detected with non-digitized modes of data collection. Using digitized pen technology in 106 participants grouped by Age (younger/older) and Affect (euthymic/unmedicated depressed), we recorded cognitive and motor output by capturing how the clock is drawn rather than focusing on the final product. We divided time to completion (TTC) for Command and Copy conditions of the dCDT into metrics of percent of drawing (%Ink) versus non-drawing (%Think) time. We also obtained composite Z-scores of cognition, including attention/information processing (AIP), to explore associations of %Ink and %Think times to cognitive and motor performance. Despite equivalent TTC, %Ink and %Think Command times (Copy n.s.) were significant (AgeXAffect interaction: p=.03)-younger depressed spent a smaller proportion of time drawing relative to thinking compared to the older depressed group. Command %Think time negatively correlated with AIP in the older depressed group (r=-.46; p=.02). Copy %Think time negatively correlated with AIP in the younger depressed (r=-.47; p=.03) and older euthymic groups (r=-.51; p=.01). The dCDT differentiated aspects of psychomotor slowing in depression regardless of age, while dCDT/cognitive associates for younger adults with depression mimicked patterns of older euthymics.

Gait characteristics in patients with major depression performing cognitive and motor tasks while walking

Depressed patients demonstrate alterations in motor and cognitive functioning that can affect their adjustments to the variations in everyday life environment. The objective was to explore gait parameters and variability of patients with major depressive disorder in dual task walking situations. Eight patients and 20 healthy controls performed motor, mental and combined motor+mental tasks while walking. Calculated parameters were cycle time, stride length, swing time, double support time and their coefficients of variation (CV). Patients demonstrated greater gait variability (swing time CV) than controls during baseline walk (t(26)=2.64, p<0.05) and motor dual task (t(26)=3.68, p<0.05). Moreover, the transition from mental to combined task decreased stride length (M=126.48±15.35 and M=121.19±13.55, p<0.001) and increased double support time (M=0.266±0.072 and M=0.287±0.076, p<0.01) only in controls. Also, gait variability increased in controls during the combined task, while remaining the same or decreasing in patients. Tasks that required greater cognitive involvement affected gait variability in patients more than controls, but only up to a certain level, after which patients׳ stability appeared unaffected by the increase of cognitive demand. This could be explained by a tendency of patients to neglect complex cognitive tasks while walking in order to preserve stability and prevent possible falls.

Psychomotor retardation in depression: a systematic review of diagnostic, pathophysiologic, and therapeutic implications

Psychomotor retardation is a central feature of depression which includes motor and cognitive impairments. Effective management may be useful to improve the classification of depressive subtypes and treatment selection, as well as prediction of outcome in patients with depression. The aim of this paper was to review the current status of knowledge regarding psychomotor retardation in depression, in order to clarify its role in the diagnostic management of mood disorders. Retardation modifies all the actions of the individual, including motility, mental activity, and speech. Objective assessments can highlight the diagnostic importance of psychomotor retardation, especially in melancholic and bipolar depression. Psychomotor retardation is also related to depression severity and therapeutic change and could be considered a good criterion for the prediction of therapeutic effect. The neurobiological process underlying the inhibition of activity includes functional deficits in the prefrontal cortex and abnormalities in dopamine neurotransmission. Future investigations of psychomotor retardation should help improve the understanding of the pathophysiological mechanisms underlying mood disorders and contribute to improving their therapeutic management.

Psychomotor retardation in depression: a systematic review of diagnostic, pathophysiologic, and therapeutic implications

Psychomotor retardation is a central feature of depression which includes motor and cognitive impairments. Effective management may be useful to improve the classification of depressive subtypes and treatment selection, as well as prediction of outcome in patients with depression. The aim of this paper was to review the current status of knowledge regarding psychomotor retardation in depression, in order to clarify its role in the diagnostic management of mood disorders. Retardation modifies all the actions of the individual, including motility, mental activity, and speech. Objective assessments can highlight the diagnostic importance of psychomotor retardation, especially in melancholic and bipolar depression. Psychomotor retardation is also related to depression severity and therapeutic change and could be considered a good criterion for the prediction of therapeutic effect. The neurobiological process underlying the inhibition of activity includes functional deficits in the prefrontal cortex and abnormalities in dopamine neurotransmission. Future investigations of psychomotor retardation should help improve the understanding of the pathophysiological mechanisms underlying mood disorders and contribute to improving their therapeutic management.

Adult age-dependent differences in resting-state connectivity within and between visual-attention and sensorimotor networks

Healthy aging is accompanied by structural and functional changes in the brain, among which a loss of neural specificity (i.e., dedifferentiation) is one of the most consistent findings. Little is known, however, about changes in interregional integration underlying a dedifferentiation across different functional systems. In a large sample (n = 399) of healthy adults aged from 18 to 85 years, we analyzed age-dependent differences in resting-state (RS) (task-independent) functional connectivity (FC) of a set of brain regions derived from a previous fMRI study. In that study, these regions had shown an age-related loss of activation specificity in visual-attention (superior parietal area 7A and dorsal premotor cortex) or sensorimotor (area OP4 of the parietal operculum) tasks. In addition to these dedifferentiated regions, the FC analysis of the present study included “task-general” regions associated with both attention and sensorimotor systems (rostral supplementary motor area and bilateral anterior insula) as defined via meta-analytical co-activation mapping. Within this network, we observed both selective increases and decreases in RS-FC with age. In line with regional activation changes reported previously, we found diminished anti-correlated FC for inter-system connections (i.e., between sensorimotor-related and visual attention-related regions). Our analysis also revealed reduced FC between system-specific and task-general regions, which might reflect age-related deficits in top-down control possibly leading to dedifferentiation of task-specific brain activity. Together, our results underpin the notion that RS-FC changes concur with regional activity changes in the healthy aging brain, presumably contributing jointly to age-related behavioral changes.

Neuronal differences between chronic low back pain and depression regarding long-term habituation to pain

BACKGROUND

Longitudinal studies of experimental pain are rare and little is known about the differences regarding sensitization and habituation over longer periods in patients with chronic pain or depression compared with controls.

METHODS

We used a standardized longitudinal painful heat paradigm that was designed to induce long-term habituation in 19 patients with chronic low back pain (CLBP), 21 patients with depression (DEP) and 21 healthy participants (controls) over a time course of eight consecutive days. We applied functional magnetic resonance imaging on the first and last day of this period and after 3 months.

RESULTS

Although the pain paradigm was standardized, patients with DEP exhibited significantly higher pain thresholds and a trend to higher pain ratings and, in functional imaging, showed less activation of the operculum and the secondary somatosensory cortex (S2) as compared to patients with CLBP and controls. Conversely, patients with CLBP showed increased activation in the anterior insula and parietal operculum as compared to patients with DEP and controls. Within session, all participants sensitized to pain, which was associated with higher activation levels in the thalamus, amygdala, midcingulate cortex, and sensory and motor areas. However, patients with depression showed significantly less activation in midbrain and brainstem areas.

CONCLUSION

Given that pain and depression potentiate each other clinically, our data suggest that this may involve different cortical pain areas.

Motor imagery in bipolar depression with slowed movement

We hypothesized that motor retardation in bipolar depression is mediated by disruption of the pre-executive stages of motor production. We used functional magnetic resonance imaging to investigate neural activity during motor imagery and motor execution to elucidate whether brain regions that mediate planning, preparation, and control of movement are activated differently in subjects with bipolar depression (n = 9) compared with healthy controls (n = 12). We found significant between-group differences. During motor imagery, the patients activated the posterior medial parietal cortex, the posterior cingulate cortex, the premotor cortex, the prefrontal cortex, and the frontal poles more than the controls did. Activation in the brain areas involved in motor selection, planning, and preparation was altered. In addition, limbic and prefrontal regions associated with self-reference and the default mode network were altered during motor imagery in bipolar depression with motor retardation.

Differential effects of dopaminergic medication on basic motor performance and executive functions in Parkinson's disease

BACKGROUND

Patients with Parkinson's disease (PD) often show deficits in the self-initiation and selection of movements, which can be partly compensated for by external cues. We here investigated impairments in the initiation and selection of self-initiated or externally cued movements in PD. Specifically, we assessed how behavioral changes relate to medication, disease severity, and basic motor or cognitive deficits.

METHODS

Seventeen akinetic-rigid PD patients and 16 healthy controls (HC) performed a computerized motor task assessing differences between internally and externally triggered movements and reaction times. Patients performed the task twice in a randomized fashion, once with their regular dopaminergic medication and once 12h after withdrawal of medication. Additionally, all subjects underwent comprehensive neuropsychological and motor assessments.

RESULTS

Compared to HC, patients showed a significant slowing across all tasks. Furthermore, patients showed a selective deficit of movement initiation as indexed by longer reaction times when movement lateralization was internally chosen as opposed to being externally cued. This deficit correlated significantly with motor scores of the Unified Parkinson's Disease Rating Scale (UPDRS). Notably, there was no main effect of dopaminergic medication ("ON"/"OFF") on internally and externally triggered movements despite significant improvement of UPDRS and maximum finger tapping frequency in the "ON" state.

DISCUSSION

Our results suggest that disease severity in PD patients is related to disturbances in internal action initiation, selection and simple decision processes. Moreover, the data add further support to the notion that dopaminergic medication differentially affects motor and cognitive performance in PD. These findings imply that disturbances in executive functions in PD are also influenced by factors other than reduced dopaminergic activity.