Designing a mHealth clinical decision support system for Parkinson's disease: a theoretically grounded user needs approach.

BACKGROUND: Despite the established evidence and theoretical advances explaining human judgments under uncertainty, developments of mobile health (mHealth) Clinical Decision Support Systems (CDSS) have not explicitly applied the psychology of decision making to the study of user needs. We report on a user needs approach to develop a prototype of a mHealth CDSS for Parkinson's disease (PD), which is theoretically grounded in the psychological literature about expert decision making and judgement under uncertainty. METHODS: A suite of user needs studies was conducted in 4 European countries (Greece, Italy, Slovenia, the UK) prior to the development of PD_Manager, a mHealth-based CDSS designed for Parkinson's disease, using wireless technology. Study 1 undertook Hierarchical Task Analysis (HTA) including elicitation of user needs, cognitive demands and perceived risks/benefits (ethical considerations) associated with the proposed CDSS, through structured interviews of prescribing clinicians (N = 47). Study 2 carried out computational modelling of prescribing clinicians' (N = 12) decision strategies based on social judgment theory. Study 3 was a vignette study of prescribing clinicians' (N = 18) willingness to change treatment based on either self-reported symptoms data, devices-generated symptoms data or combinations of both. RESULTS: Study 1 indicated that system development should move away from the traditional silos of 'motor' and 'non-motor' symptom evaluations and suggest that presenting data on symptoms according to goal-based domains would be the most beneficial approach, the most important being patients' overall Quality of Life (QoL). The computational modelling in Study 2 extrapolated different factor combinations when making judgements about different questions. Study 3 indicated that the clinicians were equally likely to change the care plan based on information about the change in the patient's condition from the patient's self-report and the wearable devices. CONCLUSIONS: Based on our approach, we could formulate the following principles of mHealth design: 1) enabling shared decision making between the clinician, patient and the carer; 2) flexibility that accounts for diagnostic and treatment variation among clinicians; 3) monitoring of information integration from multiple sources. Our approach highlighted the central importance of the patient-clinician relationship in clinical decision making and the relevance of theoretical as opposed to algorithm (technology)-based modelling of human judgment.

Absence of gaze direction effects on EEG measures of sensorimotor function.

OBJECTIVE: Gaze direction is known to modulate the activation patterns of sensorimotor areas as seen at the single cell level and in functional magnetic resonance imaging (fMRI). To determine whether such gaze direction effects can be observed in scalp-recorded electroencephalogram (EEG) measures of sensorimotor function we investigated somatosensory evoked potentials (SEPs) and steady state movement related cortical potentials (MRPs). METHODS: In two separate experiments, SEPs were elicited by electrical stimulation of the median nerve (experiment 1) and steady state MRPs were induced by 2 Hz tapping paced by an auditory cue (experiment 2), while subjects directed their gaze 15 degrees to the left or to the right. RESULTS: Gaze direction failed to produce any appreciable differences in the waveforms of the SEPs or MRPs. In particular, there was no effect on peak amplitude, peak latency and peak scalp topography measures of SEP and MRP components, or on spatial or temporal parameters of dipole models of the underlying cortical generators. Additional frequency domain analyses did not reveal reliable gaze-related changes in induced power at electrode sites overlying somatosensory and motor areas, or in coherence between pairs of parietal, central and frontal electrodes, across a broad range of frequencies. CONCLUSIONS: EEG measures of sensorimotor function, obtained in a non-visual motor task, are insensitive to modulatory effects of gaze direction in sensorimotor areas that are observable with fMRI.

Proprioceptive sensory function in Parkinson's disease and Huntington's disease: evidence from proprioception-related EEG potentials.

In both Parkinson's disease and Huntington's disease, proprioceptive sensory deficits have been suggested to contribute to the motor manifestations of the disease. Here, proprioceptive sensory function was investigated in Parkinson's disease patients, Huntington's disease patients, and healthy control subjects (each group n=8), using proprioception-related evoked potentials. Proprioception-related potentials were elicited by passive index finger movements and measured with high-density EEG. Conventional median nerve somatosensory evoked potentials (mnSEPs) were recorded in the same session. Analysis included amplitude and latency measures from selected scalp electrodes and dipole source reconstruction. We found a proprioception-related N90 component of normal latency in both Parkinson's disease and Huntington's disease. The source strength of the underlying cortical generator was normal in Parkinson's disease, but marginally reduced in Huntington's disease. Using the source location of the N20-P20 component of the mnSEP as a landmark for postcentral area 3b, the N90 was localized to the precentral motor cortex. At a latency around 170-180 ms proprioception-related potentials were explained by bilateral sensory cortex activation with an altered distribution in Parkinson's disease and a reduction of ipsilateral activation in Huntington's disease. Together, the results show largely normal early proprioception-related potentials, but changes in the cortical processing of kinaesthetic signals at longer latencies in both diseases.

Proprioception-related evoked potentials: origin and sensitivity to movement parameters.

Reafferent electroencephalography (EEG) potentials evoked by active or passive movement are largely dependent on muscle spindle input, which projects to postrolandic sensory areas as well as the precentral motor cortex. The origin of these proprioception-related evoked potentials has previously been studied by using N20-P20 source locations of the median nerve somatosensory evoked potential as an landmark for postcentral area 3b. As this approach has yielded contradictory findings, likely due to spatial undersampling, we applied dipole source analysis on two independently collected sets of high-density EEG data, containing the proprioception-related N90 elicited by passive finger movement, and the N20-P20 elicited by median nerve stimulation. In addition, the influence of movement parameters on the N90 was explored by varying amplitude/duration and direction of passive movements. The results showed that the proprioceptive N90 component was not influenced by movement direction, but had a duration that covaried with the duration of the movement. Sources were localized in the precentral cortex, located on average 10 mm anterior to the N20-P20 sources. The latter result supports earlier claims that the motor cortex is involved in the generation of proprioception-related EEG potentials.

The effects of extrinsic context on nicotine discrimination.

There is evidence from memory studies that context acquired in parallel with the encoded material will facilitate retrieval. However, relatively little is known of how context affects drug discrimination behaviour in humans. The present study employs conventional drug discrimination procedures to investigate the effects of music, as an external cue, on nicotine drug discrimination. Subjects were trained to discriminate a low dose of nicotine (1 mg) from placebo while listening to two different types of music [elated (EL) and depressant (DE): thought to induce happy and sad mood respectively]. Half of the subjects received EL music with nicotine and DE with placebo and the other half vice versa. At the end of training, subjects who reached the criterion (80% of trials identified correctly) entered the generalization phase and were required to discriminate different doses of nicotine (0, 0.25, 0.5 and 1 mg) by indicating how similar each sample was to the training dose. Generalization took place in the presence of either EL or DE music. Nicotine-appropriate responding during generalization was linearly related to dose, with subjects being able to distinguish 0.5mg of nicotine from placebo. Nicotine-appropriate responding at generalization was higher when the context (type of music) was the same as the one employed during discrimination training when nicotine was administered (i.e. a context-dependent generalization effect was present). In addition, it was shown that the context-dependent effect was due to the properties of the EL music. These data provide the first evidence that extrinsic context can facilitate nicotine discrimination in humans. In addition, the findings suggest that this facilitatory effect is not a general effect but is sensitive to specific attributes of the context.