Usefulness of laser-evoked potentials and quantitative sensory testing in the diagnosis of neuropathic spinal cord injury pain: a multiple case study.

STUDY DESIGN: A retrospective study. OBJECTIVES: The aim of this study was to investigate the contribution of laser-evoked potentials (LEPs) and quantitative sensory testing (QST) to the diagnosis of neuropathic pain in patients with spinal cord injury (SCI) and inconclusive magnetic resonance imaging (MRI) findings. SETTING: A multidisciplinary pain center. METHODS: QST (DFNS protocol) and Tm-YAG-laser stimulation of the skin were applied within the pain site corresponding with dermatomes of altered sensation. Available MRI scans were reviewed. RESULTS: Thirteen individuals (50±16 years) with SCI were examined. In four cases with no detectable neural lesion on MRI, all QST but three LEP were abnormal. In four patients with poorly defined spinal lesion on MRI, all QST but three LEP only were abnormal. In four cases where pain was not matching adequately with MRI lesions, all patients had abnormal LEP and QST. In one patient showing a spinal cord atrophy, LEP was normal but QST was abnormal. Findings supported the diagnoses at-level (n=5) and below-level (n=8) SCI pain. Spinothalamic tract function assessed by LEP was normal in three cases, but QST was abnormal in all cases. CONCLUSIONS: As QST is a psychophysical examination depending on patient cooperation, we suggest that the combination of QST and LEP might be a valuable diagnostic tool to detect lesions of the somatosensory system in a subgroup of patients with neuropathic spinal cord injury pain and inconclusive MRI findings.

Therapeutic Body Wraps in Swiss public adult acute inpatient wards. A retrospective descriptive cohort study.

WHAT IS KNOWN ON THE SUBJECT?: Various expert opinions reported relational benefits and tranquilizing effects of therapeutic body wraps (TBW) in adults experiencing high anxiety in the context of psychosis. Yet, this tranquilizing effect was never investigated in larger samples and in the context of modern psychopharmacology. WHAT THIS PAPER ADDS TO EXISTING KNOWLEDGE?: This is the first study to establish descriptive statistics of this mind-body therapy in French-speaking Switzerland where TBWs are routinely used in two public psychiatric hospitals. It brings knowledge on patients nowadays treated with TBW. Moreover, it opens a new area of investigation on the potential of this nursing technique, which may contribute to reduce anxiolytic medication in severely ill patients. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: This study sheds light on a clinical practice in mental health nursing and upon nurses' specific contribution to psychiatric clinic. It investigates a potential for TBWs to reduce the use of anxiolytic medications by patients who agreed to have TBW as part of their treatment. It may help to inform the mental health nursing practice. ABSTRACT: Introduction Many patients suffering from serious mental illness experience severe anxiety and those with psychosis often report the feeling of their bodies falling apart. While it is believed that these patients benefit from therapeutic body wraps (TBWs), the use of this adjunct therapy has rarely been studied in adult patients. Aims The aim of this study was to obtain descriptive statistics on the clinical, social-demographic and institutional reality of TBW therapy in Swiss public adult inpatient wards. Methods Retrospective data related to a cohort of 172 adult inpatients were retrieved from records of two public hospitals. Correlations between TBW and the prescriptions of lorazepam were explored. Results TBWs were primarily used for patients diagnosed with either schizophrenia, schizotypal, delusional and other non-mood psychotic disorders or mood disorders. Patients had, on average, four psychiatric hospitalizations, and in 30% of the cases, TBWs were offered during the first hospitalization. Moreover, TBWs were mostly practiced by nurses. Body wraps were potentially associated with a reduction in both anxiolytic and neuroleptic drugs. Discussion/Implication for practice Based on our results, TBW might contribute to the clinical management of anxiety by nurses. The efficacy of TWB regarding anxiety has yet to be investigated in a randomized controlled trial.

Pain assessment according to the International Spinal Cord Injury Pain classification in patients with spinal cord injury referred to a multidisciplinary pain center.

STUDY DESIGN: This is a retrospective study. OBJECTIVES: The aim of this study was to investigate the epidemiology of pain types in patients with spinal cord injury (SCI) according to the International Spinal Cord Injury Pain (ISCIP) classification. SETTING: This study was conducted in a multidisciplinary pain center. METHODS: Socio-demographic and clinical data were examined and ISCIP classification was applied. RESULTS: Sixty-six individuals (51±13 years) with SCI had pain, a lesion older than 5 years in 67% and a pain history older than 5 years in 54% of patients. According to the ISCIP classification, nociceptive pain was present in 58% (musculoskeletal pain) and 3% (visceral pain) of the patients. At-level, below-level neuropathic pain and other neuropathic pain were observed, respectively in 53, 42 and 5% of patients. Unknown pain type was found in 8% of patients. Patients with complete lesions showed significantly more frequent neuropathic pain (P=0.021) and more frequent at-level SCI pain (P=0.00) compared with those with incomplete lesions. Patients with paraplegia had more often at-level pain (P=0.00), whereas patients with tetraplegia reported more often below-level pain (P=0.00). Patients had severe pain (mean intensity: 8.2 (±1.6) on a 0 to 10 numerical scale) and showed high grades of pain chronicity. Mild to severe depression and anxiety were present, respectively in 53 and 56% of patients. The health-related quality of life was low. CONCLUSION: The use of the ISCIP classification in a clinical setting is mirroring the very complex pain situation in patients with SCI referred to a multidisciplinary pain center, and it might be an important step for adequate pain therapy.

Test-retest reliability of thermal quantitative sensory testing on two sites within the L5 dermatome of the lumbar spine and lower extremity.

INTRODUCTION: Quantitative sensory testing (QST) is widely used in human research to investigate the integrity of the sensory function in patients with pain of neuropathic origin, or other causes such as low back pain. Reliability of QST has been evaluated on both sides of the face, hands and feet as well as on the trunk (Th3-L3). In order to apply these tests on other body-parts such as the lower lumbar spine, it is important first to establish reliability on healthy individuals. The aim of this study was to investigate intra-rater reliability of thermal QST in healthy adults, on two sites within the L5 dermatome of the lumbar spine and lower extremity. METHODS: Test-retest reliability of thermal QST was determined at the L5-level of the lumbar spine and in the same dermatome on the lower extremity in 30 healthy persons under 40 years of age. Results were analyzed using descriptive statistics and intraclass correlation coefficient (ICC). Values were compared to normative data, using Z-transformation. RESULTS: Mean intraindividual differences were small for cold and warm detection thresholds but larger for pain thresholds. ICC values showed excellent reliability for warm detection and heat pain threshold, good-to-excellent reliability for cold pain threshold and fair-to-excellent reliability for cold detection threshold. ICC had large ranges of confidence interval (95%). CONCLUSION: In healthy adults, thermal QST on the lumbar spine and lower extremity demonstrated fair-to-excellent test-retest reliability.

Maturational changes in the thermoalgesic system in humans from childhood to adulthood revealed by CO(2) laser evoked brain potentials following cutaneous heat stimuli.

Possible maturational changes in the thermoalgesic system were studied by reaction times (RT) and late (Adelta-fibre) laser evoked potentials (LEPs) following CO(2) laser heat stimulation of the hand in healthy children (n=12) and young adults (n=12). In children (10+/-2 years) LEPs presented a negative-positive complex with maximum amplitude (peak-to-peak 71+/-35 microV) at the vertex and latencies of 248+/-82 and 433+/-104 ms, respectively. As compared to adults (24+/-3 years), children had a significant increased peak-to-peak amplitude (+25.7 microV; P=0.03) although no difference in latencies and topography. Median RT (710 ms) was also significantly increased (+312 ms; P<0.005) in children. A decrease in RT and late LEP amplitude from childhood to adulthood may reflect aspects of maturation in sensory processing of the thermoalgesic system.

Scalp topography of ultralate (C-fibres) evoked potentials following thulium YAG laser stimuli to tiny skin surface areas in humans.

AIM: To investigate (1) the scalp topography of ultralate laser evoked potentials (LEPs) related to C-fibre activation, which can directly be obtained by thulium YAG (Tm YAG) laser stimulation of tiny skin surface areas (about 0.23 mm(2)) and (2) the influence of the performance of a motor task on ultralate LEPs. METHODS: Laser stimuli were applied to the dorsum of the left hand. LEPs were recorded with 58 scalp electrodes from 9 healthy subjects in two different conditions, with and without a reaction time (RT) task (press a button upon detection). RESULTS: On high resolution electroenchephalogram recordings, ultralate LEPs were characterized by a broad positive component (peak latency: 1133+/-91 ms) with maximum amplitude about the vertex. Moreover, the performance of a RT task had no influence on latency, amplitude and topographical patterns of two maps chosen at the positive peak latency in ultralate LEPs. Nevertheless, a negative inflexion (latency 1300 ms) appeared after the positive component in the task condition possibly reflecting movement-related potentials. CONCLUSION: Tm YAG laser stimulation of tiny skin surface areas allows recording the dynamic scalp topography of ultralate (C-fibres) LEPs, with or without the performance of a RT task.

Dipole analysis of ultralate (C-fibres) evoked potentials after laser stimulation of tiny cutaneous surface areas in humans.

Ultralate (C-fibres) laser evoked potentials (LEP) can be obtained by stimulation of a tiny skin surface area (0.23 mm(2)). Since their generators are unknown up to now, we performed brain source analyses of ultralate LEPs using high resolution electroencephalography (64 channels) and a realistic head model that was based on individual magnetic resonance images. Ultralate LEPs were characterized by a negative-positive complex with a large positive component maximal at the vertex. Source analysis revealed that ultralate LEPs could be explained by two dipole sources in the upper bank of the contralateral and ipsilateral Sylvian fissure (SII) and one dipole in the median region corresponding to the anterior cingulate gyrus.

Determination of nerve conduction velocity of C-fibres in humans from thermal thresholds to contact heat (thermode) and from evoked brain potentials to radiant heat (CO2 laser).

This study was designed to estimate and compare nerve conduction velocity (NCV) of cutaneous heat-sensitive C-fibres obtained using two methods. The first is a method based on reaction times to different rates of temperature change produced by a large contact thermode (Thermotest). The second is a novel method based on ultra-late-evoked brain potentials to CO2 laser stimuli with tiny beam sections (< 0.25 mm2), allowing selective and direct activation of very slow conducting afferents. Both methods were applied on three sites of the right leg (foot, knee and thigh) of ten healthy subjects. When based on the reaction times to contact heat, NCV estimations were 0.4 +/- 0.22 m/s for the proximal segment (knee-thigh) and 0.6 +/- 0.23 m/s for the distal segment (foot-knee). When based on the difference in latency of the ultra-late positivity of laser-evoked brain potentials, NCV estimations were respectively 1.4 +/- 0.77 m/s and 1.2 +/- 0.55 m/s. For both methods, the difference in NCV between proximal and distal limb segments was not significant. Although both methods give NCV estimations within the range of C-fibres, the systematic difference between NCV obtained from each method may result from the activation of subpopulations of C-fibres with different NCV depending on the method of stimulation (low-threshold thermal receptors by the thermode and thermal nociceptors by the CO2 laser). Considering the difficulty of investigating peripheral fibres with slow conduction velocities (C-fibres) in humans, the methods used in the present study may be useful tools in both experimental and clinical situations.