Transcranial Direct Current Stimulation and Visual Illusion Effect According to Sensory Phenotypes in Patients With Spinal Cord Injury and Neuropathic Pain.

Treatment of neuropathic pain (NP) in patients with spinal cord injury (SCI) remains a major challenge. The aim of the present study is to investigate if the effect of transcranial direct current stimulation combined with visual illusion, following a previously published protocol, has differential effects on pain-related sensory symptoms according to sensory phenotypes profiles. One hundred and thirty SCI patients with NP participated in this open-label trial. Sixty-five patients were given a daily 20-minutes combined treatment of transcranial direct current stimulation and visual illusion for 2 weeks. Sixty-five patients served as a control group. Clinical assessment was performed before and 2 weeks later, by using Neuropathic Pain Symptom Inventory (NPSI), Brief Pain Inventory, and Patient Health Questionnaire-9. There was significant improvement in the combined treatment group according to NPSI, Brief Pain Inventory, and Patient Health Questionnaire-9, but no changes in the control group. Following a cluster analysis of NPSI items at baseline assessment, 5 subgroups of patients with different pain-related characteristics were identified among the treated group, although differences between clusters were not significant. There was also improvement in mood, sleep quality, and enjoyment of life in the treated group. Despite a reduction of NP with the combined treatment, the analysis of sensory phenotype pain profiles does not provide a predictive value regarding the analgesic results of this combined neuromodulatory treatment. PERSPECTIVE: In this article we confirm the analgesic effect of a combined neuromodulatory therapy, transcranial direct current stimulation associated with visual illusion in patients with NP after an SCI. We have identified 5 clusters of NP with distinct sensory phenotypes, but there was not any specific sensory phenotype cluster that significantly responded to the combined therapy better than the other.

Gestural Interaction and Visual Illusion for Lower Limbs' Neuropathic Pain Treatment.

Pain caused by a lesion or a disease affecting the somatosensory nervous system is known as Neuropathic pain. It has been shown that neuropathic pain can be treated with the combination of simultaneous transcranial direct current stimulation and the generation of the visual illusion that the patient retains control of the affected limbs. For persons with neuropathic pain in the lower limbs, the visual illusion consists of an image of the patient walking normally. Such a visual illusion has classically been generated by using a physical mirror and a projector. The objective of this paper is to develop and validate a computer-based version of the visual illusion, including Gestural Control. The developed system has been validated in a trial and has been successfully implanted in daily clinical practice in a reference neurorehabilitation hospital. A retrospective statistical analysis shows that the patients treated with the computer-based system reduce their pain level significantly more than the patients treated with the mirror and projector treatment before the introduction of the computer-based version. Furthermore, it also makes possible to bring the therapy to the home of the patients, where the treatment can be self-administered while still being monitored by the clinical staff.

Depression in Individuals With Traumatic and Nontraumatic Spinal Cord Injury Living in the Community.

OBJECTIVE: To assess depression in a sample of individuals with spinal cord injury (SCI) living in the community, and to determine the prevalence of probable major depressive disorder (PMDD) among those with traumatic spinal cord injury (T-SCI) and those with nontraumatic spinal cord injury (NT-SCI). DESIGN: Cross-sectional. SETTING: Data were collected on individuals with SCI now living in the community, who completed a comprehensive follow-up assessment at the hospital. PARTICIPANTS: Individuals with T-SCI or NT-SCI (N=831) completed the Patient Health Questionnaire-9 (PHQ-9) and were included. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: The PHQ-9 was used to detect the presence of PMDD and to measure the severity of the depression. RESULTS: The most frequent etiology of SCI was T-SCI (66.9%). Overall, 16.2% of participants met the criteria for PMDD; however, a higher prevalence was noted for individuals with NT-SCI (21.1%) than for individuals with T-SCI (13.8%). Risk factors between T-SCI and NT-SCI did not differ greatly. Female sex, chronic pain, and lower levels of/difficulties in participation were associated with the presence of PMDD. CONCLUSIONS: PMDD appears to occur at a higher rate in individuals with NT-SCI, with greater symptom severity. The finding that problems with participation are directly associated with depression raises the need for specific treatment goals, with the aim of empowering individuals with SCI to reintegrate into the community. Potential stress factors (eg, environmental barriers, limited participation options) should be addressed accordingly.

Meta-analysis of placebo responses in central neuropathic pain: impact of subject, study, and pain characteristics.

The placebo response is a complex construct related to psychobiological effects, as well as natural history and regression to the mean. Moreover, patient and study design characteristics have also been proposed as significantly affecting placebo responses. The aim of the current investigation was to identify factors that contribute to variable placebo responses in clinical trials involving individuals with central neuropathic pain. To this end, we performed a systematic review and meta-analysis of placebo-controlled trials examining pharmacological and noninvasive brain stimulation interventions for central neuropathic pain. Study design, subject characteristics, and pain ratings for the placebo group were extracted from each trial. Pooling of results and identification of moderating factors were carried out using random effects meta-analysis and meta-regression techniques. A total of 39 published trials met the inclusion criteria (spinal cord injury, n = 26; stroke, n = 6; multiple sclerosis, n = 7). No significant publication bias was detected. Overall, there was a significant effect for placebo to reduce central pain (-0.64, CI: -0.83 to -0.45). Smaller placebo responses were associated with crossover-design studies, longer pain duration, and greater between-subject baseline pain variability. There were no significant effects for neurological condition (stroke vs multiple sclerosis vs spinal cord injury) or the type of intervention (eg, pharmacological vs noninvasive brain stimulation). In a planned subanalysis, the severity of damage in the spinal cord also had no significant effect on the placebo response. Further study is warranted to identify factors that may explain the impact of pain duration on the placebo response at the individual subject level.

Evoked potentials and quantitative thermal testing in spinal cord injury patients with chronic neuropathic pain.

OBJECTIVE: Neuropathic pain (NP) is a common symptom following spinal cord injury (SCI). NP may be associated with altered processing of somatosensory pathways in dermatomes rostral to the injury level. To explore this possibility, the characteristics of contact heat evoked potentials (CHEPs) and quantitative thermal testing (QTT) were studied at and above the lesion level in SCI patients with NP. The goal was to determine processing abnormalities correlated with data from clinical evaluations. METHODS: Thirty-two subjects with chronic NP, 22 subjects without NP and 16 healthy control subjects were studied. Warm and heat pain thresholds were determined both at and above SCI level. CHEPs were recorded above SCI level and subjects rated their perception of evoked heat pain using a numerical rating scale. RESULTS: CHEPs were not different between the three groups. Evoked pain perception in SCI subjects with NP was significantly higher than in SCI subjects without NP and healthy controls. Heat pain threshold was significantly lower in subjects with NP in comparison to both groups. CONCLUSIONS: Our findings indicate that processing of somatosensory inputs from dermatomes rostral to the injury level is abnormal in SCI subjects with NP. SIGNIFICANCE: SCI somatosensory processing alteration may contribute to the understanding of the mechanisms underlying NP and secondary changes to NP in SCI.

Knowledge discovery about quality of life changes of spinal cord injury patients: clustering based on rules by states.

In this paper, an integral Knowledge Discovery Methodology, named Clustering based on rules by States, which incorporates artificial intelligence (AI) and statistical methods as well as interpretation-oriented tools, is used for extracting knowledge patterns about the evolution over time of the Quality of Life (QoL) of patients with Spinal Cord Injury. The methodology incorporates the interaction with experts as a crucial element with the clustering methodology to guarantee usefulness of the results. Four typical patterns are discovered by taking into account prior expert knowledge. Several hypotheses are elaborated about the reasons for psychological distress or decreases in QoL of patients over time. The knowledge discovery from data (KDD) approach turns out, once again, to be a suitable formal framework for handling multidimensional complexity of the health domains.