Pain reduction by infrared light-emitting diode irradiation: a pilot study on experimentally induced delayed-onset muscle soreness in humans.

The present pilot study investigated the analgesic efficacy of light-emitting diode (LED). In view of a standardised and controlled pain reduction study design, this in vivo trial was conducted on experimentally induced delayed-onset muscle soreness (DOMS). Thirty-two eligible human volunteers were randomly assigned to either an experimental (n=16) or placebo group (n=16). Immediately following the induction of muscle soreness, perceived pain was measured by means of a visual analog scale (VAS), followed by a more objective mechanical pain threshold (MPT) measurement and finally an eccentric/concentric isokinetic peak torque (IPT) assessment. The experimental group was treated with infrared LED at one of both arms, the other arm served as control. Irradiation lasted 6 min at a continuous power output of 160 mW, resulting in an energy density of 3.2 J/cm(2). The subjects of the placebo group received sham irradiation at both sides. In post-treatment, a second daily assessment of MPT and VAS took place. The treatment and assessment procedure (MPT, VAS and IPT) was performed during 4 consecutive days. Statistical analysis (a general linear model followed by post hoc least significant difference) revealed no apparent significant analgesic effects of LED at the above-described light parameters and treatment procedure for none of the three outcome measures. However, as the means of all VAS and MPT variables disclose a general analgesic effect of LED irradiation in favour of the experimental group, precaution should be taken in view of any clinical decision on LED. Future research should therefore focus on the investigation of the mechanisms of LED action and on the exploration of the analgesic effects of LED in a larger randomised clinical trial and eventually in more clinical settings.

Atherosclerosis in the vertebral artery: an intrinsic risk factor in the use of spinal manipulation?

The presence of atherosclerotic plaques and their influence on the vertebral artery is of clinical importance within the scope of spinal manipulation. Manipulation may stimulate the development of atherosclerotic plaques, could detach an embolus with ensuing infarction, injure the endothelium or may directly cause a dissection in the presence of atherosclerotic plaques. In order to identify the sites and frequency of atherosclerotic plaques and to determine its relation to the tortuous course of the vertebral artery, a cadaveric study was performed. The vertebral arteries of 57 human cadavers were studied. The vertebral artery was virtually divided into four segments: the pre-vertebral (V1), the vertebral (V2), the atlanto-axial (V3), and the intracranial segment (V4). Abnormalities in the origin and course of the vertebral artery were noted, along with any associated osseous, or cartilaginous anomalies in the neck. After dissection, the artery was opened and macroscopically screened for the presence of atherosclerotic plaques. In 22.8% of the cases, no atherosclerotic plaques were present. In 35.1% of the cases, the atherosclerotic plaques were unilateral, of which 60.0% was on the left side, 40.0% on the right side, and in 42.1%, the occurrence was bilateral. Atherosclerotic plaques were significantly more present in the V3 segment than in the V1 (0.007) and V2 segment (0.049). In the V1 (P=0.008) and V2 segment (P=0.002), there was a correlation between a tortuous course of the vessel and the occurrence of atherosclerotic plaques. In individuals with marked atherosclerotic disease, stretching and compression effects of rotational manipulative techniques on atherosclerotic vessels impose a further risk factor for vertebrobasilar insufficiency. As direct evidence of atherosclerotic plaques are rarely available, therapists should avoid manipulative techniques at all levels of the cervical spine in the presence of any indirect sign of atherosclerotic disease or in the presence of calcified arterial walls or tortuosities of the vessels visible on routinely available X-ray images of the cervical or thoracic spine. It is strongly recommended, that if any doubt exists about the nature of a clinical presentation, vigorous manual procedures should be avoided until either the diagnosis is definitive or gentle manual therapy has proven effective.

A vertebral artery without atlantic and intradural sections: a case report and a review of the literature.

This report covers a case in which the right vertebral artery (VA) did not participate in the formation of the basilar artery. The artery had an external diameter of about 1 mm. It ran trough the transverse foramina of C6 through C2, then turned backward and entered the spinal canal and the dural envelope between the posterior arch of C1 and the lamina of C2 as a medullary artery to end in the spinal arteries. The basilar artery was a continuation of the left VA only. Only very few cases of non-union of the VA with the basilar artery have been previously described. Cases with extreme reduction of one of the VAs are not exceptional. This variant is clinically important. On arteriography, this extremely rare condition could easily be misdiagnosed as an obstruction. In view of manipulative therapy and in the detection of vertebrobasilar insufficiency, one has to bear in mind that cases of non-union may influence the interpretation of these tests.

Extrinsic risk factors for compromised blood flow in the vertebral artery: anatomical observations of the transverse foramina from C3 to C7.

The vertebral artery (VA) is often involved in the occurrence of complications after spinal manipulative therapy. Due to osteophytes compressing the VA anteriorly from the uncinate process or posteriorly from the facet complex, the VAs are susceptible to trauma in the transverse foramina. Such altered anatomical configurations are of major clinical significance, as spinal manipulations may result in dissection of the VA with serious consequences for the blood supply to the vertebrobasilar region. The purpose of this study is to describe numerous structural features of the third to seventh cervical vertebrae in order to contribute to the understanding of pathological conditions related to the VA. The minimal and maximal diameter of 111 transverse foramina in dry cervical vertebrae were studied. The presence of osteophytes and their influence on the VA were evaluated at the vertebral body and at the superior and inferior articular facets. The diameter of the transverse foramina increased from C3 to C6, while the transverse foramina of C7 had the smallest diameter. At all levels the mean dimensions of the left foramina were greater than those of the right side. Osteophytes from the uncinate process of C5 and C6 vertebrae were found in over 60% of dry vertebrae. Osteophytes from the zygapophyseal joints were more frequent at C3 and C4 vertebrae. About half of the osteophytes of the uncinate and of the superior articular process partially covered the transverse foramina. This was less common with those of the inferior articular facets. Osteophytes covering the transverse foramen force the VAs to meander around these obstructions, causing narrowing through external compression and are potential sites of trauma to the VAs potentially even leading to dissection. We strongly advocate that screening protocols for vertebrobasilar insufficiency (VBI) be used prior to any manipulation of the cervical spine and should include not only extension and rotation but any starting position from which the planned manipulation will be performed.

A case of abnormal findings in the course of the vertebral artery associated with an ossified hyoid apparatus. A contraindication for manipulation of the cervical spine?

OBJECTIVE: To describe a case of a simultaneous occurrence of an ossified stylohyoid ligament in a 56-year-old male cadaver and anomalies of the vertebral artery, and to consider the clinical implications for manipulative therapists. INTERVENTION AND OUTCOME: Dissection showed a simultaneous occurrence of complete developmental ossification of the left hyoid apparatus, variants of the vertebral artery, and a left superior vena cava in a 56-year-old male cadaver. DISCUSSION: Developmental variants, posttraumatic and degenerative changes of the hyoid apparatus may result in variable degrees of ossification or calcification. CONCLUSION: This unusual disorder should be considered in the differential diagnosis of facial and neck pain especially within the scope of manipulation of the upper cervical spine. Cervical spine manipulation may exacerbate existing pathological conditions of the stylohyoid apparatus, thereby irritating neurovascular structures, and induce a fracture. Developmental ossification of this apparatus might be associated with anomalies in the atlantic section of the vertebral artery which make the patient more susceptible to vertebrobasilar insufficiency. We conclude that extreme care should be taken in the presence of such an ossification to avoid trauma to the stylohyoid apparatus and maybe even because of increased vertebrobasilar risk.

Evidence of changes in sural nerve conduction mediated by light emitting diode irradiation.

The introduction of light emitting diode (LED) devices as a novel treatment for pain relief in place of low-level laser warrants fundamental research on the effect of LED devices on one of the potential explanatory mechanisms: peripheral neurophysiology in vivo. A randomised controlled study was conducted by measuring antidromic nerve conduction on the peripheral sural nerve of healthy subjects (n=64). One baseline measurement and five post-irradiation recordings (2-min interval each) were performed of the nerve conduction velocity (NCV) and negative peak latency (NPL). Interventional set-up was identical for all subjects, but the experimental group (=32) received an irradiation (2 min at a continuous power output of 160 mW, resulting in a radiant exposure of 1.07 J/cm(2)) with an infrared LED device (BIO-DIO preprototype; MDB-Laser, Belgium), while the placebo group was treated by sham irradiation. Statistical analysis (general regression nodel for repeated measures) of NCV and NPL difference scores, revealed a significant interactive effect for both NCV (P=0.003) and NPL (P=0.006). Further post hoc LSD analysis showed a time-related statistical significant decreased NCV and an increased NPL in the experimental group and a statistical significant difference between placebo and experimental group at various points of time. Based on these results, it can be concluded that LED irradiation, applied to intact skin at the described irradiation parameters, produces an immediate and localized effect upon conduction characteristics in underlying nerves. Therefore, the outcome of this in vivo experiment yields a potential explanation for pain relief induced by LED.

Green light emitting diode irradiation enhances fibroblast growth impaired by high glucose level.

BACKGROUND AND OBJECTIVE: The chronic metabolic disorder diabetes mellitus is an important cause of morbidity and mortality due to a series of common secondary metabolic complications, such as the development of severe, often slow healing skin lesions. In view of promoting the wound-healing process in diabetic patients, this preliminary in vitro study investigated the efficacy of green light emitting diode (LED) irradiation on fibroblast proliferation and viability under hyperglycemic circumstances. MATERIALS AND METHODS: To achieve hyperglycemic circumstances, embryonic chicken fibroblasts were cultured in Hanks' culture medium supplemented with 30 g/L glucose. LED irradiation was performed on 3 consecutive days with a probe emitting green light (570 nm) and a power output of 10 mW. Each treatment lasted 3 min, resulting in a radiation exposure of 0.1 J/cm2. RESULTS: A Mann-Whitney U test revealed a higher proliferation rate (p = 0.001) in all irradiated cultures in comparison with the controls. CONCLUSION: According to these results, the effectiveness of green LED irradiation on fibroblasts in hyperglycemic circumstances is established. Future in vivo investigation would be worthwhile to investigate whether there are equivalent positive results in diabetic patients.

Changes in cerebellar blood flow after manipulation of the cervical spine using Technetium 99m-ethyl cysteinate dimer.

BACKGROUND: Cervical spine manipulation is one of the many interventions practiced by health professionals to treat musculoskeletal disorders of the cervical spine. Although serious consequences of manipulation have been documented, the incidence is thought to be rare. More frequently, there may be minor transient side effects after manipulation of the cervical spine, such as headache, dizziness, and nausea. One of the hypothesis is that these side effects are caused by ischemia in the areas perfused by the vertebral arteries. OBJECTIVE: The purpose of this study was to investigate whether manipulation of the cervical spine can influence blood flow in the brain. METHODS: Single photon emission computed tomography was used to examine changes in regional cerebral blood flow caused by cervical spine manipulation (CSM) performed by a physiotherapist to 15 volunteers, using a 1-day split-dose Technetium 99m-ethyl cysteinate dimer single photon emission computed tomography activation paradigm. RESULTS: One brain region was identified showing a decreased regional cerebral blood flow after manipulation. This region was situated in the anterior lobe of the left cerebellum (-42, -48, -24). CONCLUSIONS: These findings suggest that cerebellar hypoperfusion may occur after CSM. This could explain why certain people experience headache, dizziness, or nausea after CSM. Further investigation into patient symptoms in the presence of cerebellar hypoperfusion and the possible link of these findings with other adverse reactions are warranted.

How common are side effects of spinal manipulation and can these side effects be predicted?

Little scientific support is available concerning usual and unusual reactions after spinal manipulation although such reactions are very common in clinical practice. Fifty-nine manipulative therapists were requested to enroll 15 consecutive patients attending for their first visit to receive spinal manipulation. These patients were asked to complete a questionnaire after this first visit that asked for possible risk factors for spinal manipulation and asked about any side effects after the manipulation. The participating practitioners were asked to note medical diagnosis, manipulated spinal region, number of treated areas and type of additional treatment. Four hundred and sixty five valuable responses were analysed. Two hundred and eighty three patients (60.9%) reported at least one post-manipulative reaction. The most common were headache (19.8%), stiffness (19.5%), local discomfort (15.2%), radiating discomfort (12.1%) and fatigue (12.1%). Most of these reactions began within 4 h and generally disappeared within the next 24 h. Women were more likely to report adverse effects than men (P < 0.001). Multivariate analysis showed that upper cervical manipulation (OR: 3.20; 95%CI: 1.89-7.77), use of medication (OR: 2.20; 95%CI: 1.31-3.69), gender (OR: 1.66; 95%CI: 1.01-2.75) and age (OR: 1.02; 95%CI: 1.00-1.05) were independent predictors of headache after spinal manipulation. The results of this study indicate that reactions to spinal manipulation may be relatively common but are benign in nature and of short duration. Although it is difficult to label side effects as a risk, it is important to differentiate those patients who are susceptible to side effects in order to inform them correctly.

Increased fibroblast proliferation induced by light emitting diode and low power laser irradiation.

BACKGROUND AND OBJECTIVE: As Light Emitting Diode (LED) devices are commercially introduced as an alternative for Low Level Laser (LLL) Therapy, the ability of LED in influencing wound healing processes at cellular level was examined. STUDY DESIGN/MATERIALS AND METHODS: Cultured fibroblasts were treated in a controlled, randomized manner, during three consecutive days, either with an infrared LLL or with a LED light source emitting several wavelengths (950 nm, 660 nm and 570 nm) and respective power outputs. Treatment duration varied in relation to varying surface energy densities (radiant exposures). RESULTS: Statistical analysis revealed a higher rate of proliferation (p < 0.001) in all irradiated cultures in comparison with the controls. Green light yielded a significantly higher number of cells, than red (p < 0.001) and infrared LED light (p < 0.001) and than the cultures irradiated with the LLL (p < 0.001); the red probe provided a higher increase (p < 0.001) than the infrared LED probe and than the LLL source. CONCLUSION: LED and LLL irradiation resulted in an increased fibroblast proliferation in vitro. This study therefore postulates possible stimulatory effects on wound healing in vivo at the applied dosimetric parameters.

Phonophoresis versus topical application of ketoprofen: comparison between tissue and plasma levels.

BACKGROUND AND PURPOSE: Over the last few decades, application of ultrasound has been attempted to enhance transdermal transport of several drugs, a method referred to as "phonophoresis." The purposes of this study were to examine the influence of ultrasound on the transdermal delivery of ketoprofen in humans and to compare the concentrations found after continuous and pulsed application. SUBJECTS AND METHODS: Twenty-six patients with knee disorders requiring arthroscopy were randomly assigned to 1 of 3 groups. Just before surgery, phonophoresis of a ketoprofen gel (Fastum gel) was given to group A using continuous ultrasound (1 MHz, 1.5 W/cm2, for 5 minutes). Group B received the same treatment but with pulsed ultrasound (100 Hz, 20% duty cycle). Group C received 5 minutes of sham ultrasound with the ketoprofen gel. The ultrasound head was moved over a 10-cm2 area using small, continuous, circular movements. Biopsies of adipose tissue and synovial tissue were taken during surgery to evaluate the local penetration of the drug. Blood samples also were collected to determine whether ketoprofen entered the systemic circulation. RESULTS: The concentration of ketoprofen in plasma was negligible in all 3 groups. The concentration of ketoprofen in synovial tissue differed from that in fat tissue. A difference in concentration of ketoprofen in synovial tissue was found between group C and groups A and B. The concentration of ketoprofen in fat tissue and synovial tissue was consistently higher in group B than in group A. DISCUSSION AND CONCLUSION: This study confirms that phonophoresis of ketoprofen allows the attainment of higher local concentrations, whereas systemic exposure is lower. The results indicate that, in contrast to sham phonopheresis, ultrasound can increase the transdermal delivery of ketoprofen.