Symptom perception and functioning in patients with advanced cancer

Purpose To explore how symptom perception affects functioning in patients with advanced cancer. Materials and methods We conducted a cross-sectional observational study of 459 advanced cancer patients at the national cancer center. Functioning was assessed using the World Health Organization Disability Assessment Schedule (WHODAS) II, and symptoms were evaluated using the Memorial Symptom Assessment Scale-Short Form. Confirmatory factor analysis was conducted to develop a structural model based on different symptom perceptions, such as somatic sensation and experienced symptoms. Results The structural model of disability revealed a significant direct pathway involving somatic sensation (β = 16.11, p < 0.001). Experienced symptoms significantly affected somatic sensations (β = 0.717, p < 0.001) but were not directly associated with disability. Unidimensional models exhibited a poor fit. In contrast, a complex model with first-order (somatic sensation) and second-order (experienced symptoms) factors provided an excellent fit, with comparative fit indexes (CFIs) and Tucker Lewis indexes (TLI) of more than 0.950 threshold. Conclusions Our findings suggest that relationships to functioning may vary between somatic sensations versus experienced symptoms. The structure of symptoms is best conceptualized by direct somatic sensation and indirect experienced symptoms. A better understanding of symptom perception and the relationship between symptoms and function would facilitate the development of effective rehabilitation programs.

Transient total locked-in syndrome due to vertebral and basilar artery dissection

A 52-year-old woman suddenly presented with right conjugate eye deviation, anarthria and quadriplegia, and appeared to be in a deep coma. MRI revealed a new infarct in the left cerebellar hemisphere and stenosis in the distal portion of the basilar artery caused by arterial dissection. Her deficits improved within 6 hours of onset. Moreover, on day 1, she described that she had been alert and her vision, hearing and somatic sensation had been preserved during the illness. Total locked-in syndrome should be considered while assessing patients with total immobility who are unable to communicate.

“My Body Hates Me”: A Qualitative Analysis of the Experience of Functional Nausea in Adolescent Girls and Their Mothers

Nausea is a somatic sensation typically associated with the need to vomit in order to remove a toxin from the body. When nausea occurs in the absence of a specific structural cause or toxin, it is classified as a functional gastrointestinal disorder (FGID). Functional nausea was newly recognized in 2016 as a FGID in children and little is known about its prevalence, course or patient experiences. Nausea co-occurring with functional abdominal pain in childhood has been associated with long-term risk for anxiety and ongoing somatic symptoms into young adulthood. However, few studies have focused uniquely on the experience and impact of nausea on youth. The present study aimed to qualitatively understand the experiences of adolescent girls with functional nausea and their parents. Five mother–daughter dyads were recruited from a specialized pediatric gastroenterology clinic focused on nausea and completed semi-structured interviews. Interviews were transcribed and coded using interpretive phenomenological analysis (IPA). Four main themes emerged: nausea interference, body frustration, misunderstanding of symptoms, and maternal helplessness and guilt. These themes were similar to prior studies on the experiences of youth with chronic pain but also indicated unique challenges due to nausea, such as significant food restriction and subsequent weight loss.

Human Sensation of Transcranial Electric Stimulation

Noninvasive transcranial electric stimulation is increasingly being used as an advantageous therapy alternative that may activate deep tissues while avoiding drug side-effects. However, not only is there limited evidence for activation of deep tissues by transcranial electric stimulation, its evoked human sensation is understudied and often dismissed as a placebo or secondary effect. By systematically characterizing the human sensation evoked by transcranial alternating-current stimulation, we observed not only stimulus frequency and electrode position dependencies specific for auditory and visual sensation but also a broader presence of somatic sensation ranging from touch and vibration to pain and pressure. We found generally monotonic input-output functions at suprathreshold levels, and often multiple types of sensation occurring simultaneously in response to the same electric stimulation. We further used a recording circuit embedded in a cochlear implant to directly and objectively measure the amount of transcranial electric stimulation reaching the auditory nerve, a deep intercranial target located in the densest bone of the skull. We found an optimal configuration using an ear canal electrode and low-frequency (<300 Hz) sinusoids that delivered maximally ~1% of the transcranial current to the auditory nerve, which was sufficient to produce sound sensation even in deafened ears. Our results suggest that frequency resonance due to neuronal intrinsic electric properties need to be explored for targeted deep brain stimulation and novel brain-computer interfaces.

Creating a neuroprosthesis for active tactile exploration of textures

Intracortical microstimulation (ICMS) of the primary somatosensory cortex (S1) can produce percepts that mimic somatic sensation and, thus, has potential as an approach to sensorize prosthetic limbs. However, it is not known whether ICMS could recreate active texture exploration—the ability to infer information about object texture by using one’s fingertips to scan a surface. Here, we show that ICMS of S1 can convey information about the spatial frequencies of invisible virtual gratings through a process of active tactile exploration. Two rhesus monkeys scanned pairs of visually identical screen objects with the fingertip of a hand avatar—controlled first via a joystick and later via a brain–machine interface—to find the object with denser virtual gratings. The gratings consisted of evenly spaced ridges that were signaled through individual ICMS pulses generated whenever the avatar’s fingertip crossed a ridge. The monkeys learned to interpret these ICMS patterns, evoked by the interplay of their voluntary movements and the virtual textures of each object, to perform a sensory discrimination task. Discrimination accuracy followed Weber’s law of just-noticeable differences (JND) across a range of grating densities; a finding that matches normal cutaneous sensation. Moreover, 1 monkey developed an active scanning strategy where avatar velocity was integrated with the ICMS pulses to interpret the texture information. We propose that this approach could equip upper-limb neuroprostheses with direct access to texture features acquired during active exploration of natural objects.

Creating a neuroprosthesis for active tactile exploration of textures

Intracortical microstimulation (ICMS) of the primary somatosensory cortex (S1) can produce percepts that mimic somatic sensation and thus has potential as an approach to sensorize prosthetic limbs. However, it is not known whether ICMS could recreate active texture exploration—the ability to infer information about object texture by using one’s fingertips to scan a surface. Here we show that ICMS of S1 can convey information about the spatial frequencies of invisible virtual gratings through a process of active tactile exploration. Two rhesus monkeys scanned pairs of visually identical screen objects with the fingertip of a hand avatar, controlled via a joystick and later via a brain-machine interface, to find the one with denser virtual gratings. The gratings consisted of evenly spaced ridges that were signaled through ICMS pulses generated when the avatar’s fingertip crossed each ridge. The monkeys learned to interpret these ICMS patterns evoked by the interplay of their voluntary movements and the virtual textures of each object. Discrimination accuracy across a range of grating densities followed Weber’s law of just-noticeable differences (JND), a finding that matches normal cutaneous sensation. Moreover, one monkey developed an active scanning strategy where avatar velocity was integrated with the ICMS pulses to interpret the texture information. We propose that this approach could equip upper-limb neuroprostheses with direct access to texture features acquired during active exploration of natural objects.

Evaluation of Vital Data by Presenting Feeling of Presence Using Modulated Infrared Rays

A new method of vital stimulation apart from the visual and auditory senses using modulated far-infrared rays is proposed. The somatic sense is stimulated to provide the feeling of presence of a human being. Fundamental experiments are performed, and the specifications of the stimulating device are defined. The heartbeat, breathing, and temperature change of parts of the face are observed during the irradiation of the modulated far-infrared rays. The change in the vital data of the human reaction towards the stimulation is < 3.5% and no remarkable characteristics are observed. When three subjects are questioned, a somatic sensation is reported; thus, the possibility of detecting the feeling of presence using other vital data is suggested. Further development of detection techniques using the vital data is planned in order to confirm the effectiveness of the detection of the feeling of presence.