Focal Mechanical Vibration Does not Change Laser-Pain Perception and Laser-Evoked Potentials: A Pilot Study.

BACKGROUND: Nonpainful tactile and electrical stimulation of the large myelinated fibers reduces spontaneous pain and the amplitude of laser-evoked potentials (LEPs), which represent the most reliable technique to assess the nociceptive pathway function. Focal mechanical vibration stimulates the Aß afferents selectively; thus, it is conceivable its action on nociceptive pathways. AIM: The aim of this study was to investigate the effect of vibratory stimuli, activating either both muscle and skin receptors or cutaneous afferents only on the LEPs and subjective laser-pain rating. METHODS: Ten healthy volunteers were studied. The subjects were evaluated in two different sessions to test muscle and skin receptors or cutaneous afferents only. In each session, LEPs were recorded to stimulation of the dorsal hand skin in radial and ulnar territory bilaterally, while the vibratory stimulus was delivered on the radial territory of the right forearm. RESULTS: The results showed a substantial stability of the potential N1 and N2/P2 after the two protocols, with a declining trend from the initial to the last test of the same session, probably due to habituation. Accordingly, the laser-pain perception did not change during the experimental setting. CONCLUSIONS: We conclude that a vibratory stimulus is ineffective in reducing the laser-evoked potentials and laser-pain perception.

Effects of rehabilitation treatment of the upper limb in multiple sclerosis patients and predictive value of neurophysiological measures.

BACKGROUND: Dysfunctions of the upper limbs occur in the 66% of multiple sclerosis (MS) patients. To date, no data, about the persistence of the effects of a rehabilitation treatment and no prognostic markers of functional improvement, have been established. AIM: The aim of this study was to define clinical data supporting the efficacy of a rehabilitation treatment in MS patients with upper limb impairment and to find prognostic factors for functional improvement. DESIGN: Pre-post comparison prospective study. SETTING: Two tertiary Italian MS centres: Rome and Siena. POPULATION: Twenty-five consecutive MS patients were tested for eligibility. METHODS: We multidimensionally evaluated 25 consecutive patients with MS-related upper limbs impairment through clinical objective, patient-oriented and neurophysiological measures pre and post a16-week rehabilitation treatment on upper limb sensorimotor function. RESULTS: We found a significant improvement in the Nine Hole Peg Test (9-HPT) at either sides, both at an immediate post-training visit (T1) (left: P=0.018, right: P=0.004) and at a 12-week postintervention assessment visit (T2) (left: P=0.033, right: P=0.022). We also found a positive correlation between the 12-week post-training changes in the 9-HPT and the N14-P20 interpeak of the somatosensory evoked potentials, (rho=0.374, P=0.008). CONCLUSIONS: Our study demonstrates that a rehabilitation treatment can lead to an improvement of the upper limb motor performance in MS patients which continues to persist even after 3 months of treatment-discontinuation suggesting a possible role of rehabilitation in neuroplasticity changes. Moreover, we found, in the latency of the N14-P20 interpeak, a possible prognostic marker for the effects of a upper limb rehabilitation treatment in MS patients. CLINICAL REHABILITATION IMPACT: The N14-P20 interpeak could be used as a prognostic marker of the effects of rehabilitation of the upper limb.

Focal muscle vibration in the treatment of upper limb spasticity: a pilot randomized controlled trial in patients with chronic stroke.

OBJECTIVE: To examine the clinical effect of repetitive focal muscle vibration (rMV) on the motor function of the upper extremity 1 month after treatment in patients with chronic stroke. DESIGN: We performed a pilot randomized controlled trial using a double-blind, parallel-group study design. SETTING: Medical center. PARTICIPANTS: Patients with chronic stroke (N=49). INTERVENTIONS: Patients randomly assigned to the study group (SG) received rMV, while patients in the control group (CG) received a placebo vibratory treatment. The patients and the clinical examiner were blind to the intervention. MAIN OUTCOME MEASURES: The primary endpoint was an improvement of more than .37 points on the Functional Ability Scale of the Wolf Motor Function Test (WMFT FAS). The Modified Ashworth Scale and the visual analog scale were the secondary outcome measures. All measures were administered before the treatment (t0) and 1 week (t1) and 1 month (t2) after the treatment. RESULTS: Twenty-eight patients were allocated to the SG and 21 to the CG. The analysis of variance for repeated measurements revealed a significant difference in the expression of the WMFT FAS score over time only in the SG (P=.006). The treatment was successful for 7 (33%) of 21 patients recruited in the SG and for 2 (13%) of 15 patients recruited in the CG. The relative risk was 2.5 (95% confidence interval, .60-10.39), and the number needed to treat was 5. The Wilcoxon test showed a statistically significant difference between t0 and t2 in the SG (P=.02). No adverse event was observed in the 2 groups. CONCLUSIONS: Our results suggest that rMV treatment of the upper limb may improve the functional ability of chronic stroke patients, but a larger, multicenter, randomized controlled study is needed.

Short-term effects of local microwave hyperthermia on pain and function in patients with mild to moderate carpal tunnel syndrome: a double blind randomized sham-controlled trial.

OBJECTIVE: To determine the short-term effects of local microwave hyperthermia on pain and function in patients with mild to moderate idiopathic carpal tunnel syndrome. DESIGN: Double-blind randomized sham-controlled trial. SETTING: Outpatient clinic of the Department of Physical Medicine and Rehabilitation, University Hospital. PARTICIPANTS: Twenty-two patients with idiopathic carpal tunnel syndrome, 12 of whom had bilateral involvement, for a total of 34 wrists, divided into two groups: a hyperthermia active treatment group (number of wrists = 17) and a sham-controlled group (number of wrists = 17). INTERVENTION: Six sessions, two per week, of either hyperthermia or sham treatment were provided over a period of three weeks. MAIN MEASURES: Visual analogue scale, Levine-Boston Self-Assessment Questionnaire (part I: evaluation of pain intensity; part II: evaluation of functional status) and neurophysiological assessments, were determined at baseline and at the end of the treatment. RESULTS: The hyperthermia group experienced a significant improvement in pain (visual analogue scale: P = 0.002; Levine-Boston part I: P < 0.0001) and functional status (Levine-Boston part II: P = 0.002) relative to baseline. No improvements in pain intensity or functionality were observed in the sham-treated group. Changes in pain severity between baseline and the end of treatment were larger in the hyperthermia group than in the sham-controlled group (Δ visual analogue scale P = 0.004; Δ Levine-Boston part I: P = 0.009). No differences either intra or between groups were observed for median nerve conduction velocity. CONCLUSION: Hyperthermia provides short-term improvements in pain and function in patients with mild to moderate carpal tunnel syndrome.

Prevalence of bifid median nerve at wrist assessed through ultrasound.

We performed a prospective study to evaluate the prevalence of bifid median nerve (BMN) and if it has a higher prevalence in carpal tunnel syndrome (CTS) patients than symptom-free subjects. We evaluated by ultrasound (US) 162 median nerves at wrist of 89 consecutive patients with symptoms suggestive of CTS and 104 of 52 consecutive symptom-free subjects. Neurophysiological evaluation confirmed CTS diagnosis. All patients underwent ultrasonographic evaluation of median nerve in the elbow-palm segment through high-frequency probe; BMN was arbitrarily classified as "complete" and "incomplete" on the basis of US results. BMN was observed in 16/104 wrists (15.4%) in control group and in 30/162 (18.5%) wrists in CTS group. Our study showed that BMN is frequent, not always bilateral, more often is "incomplete" and it has similar prevalence in CTS and control group. These findings suggest that BMN is not a risk factor of developing CTS.