Identification of subgroups among fibromyalgia patients.

This paper presents some hypotheses concerning the identification of homogeneous subgroups among fibromyalgia (FM) patients in order to improve the management of the disease. It also reviews the available literature about this subject. Three methods for subgrouping are discussed according to clinical features, biomarkers, and gait analysis. Clinical subgrouping based on cluster analysis has been used for the identification of homogeneous subgroups of patients and, more recently, homogeneous clinical features. So far, longitudinal studies using clinical subgroups to direct treatment and predict outcome are still required. Biomarkers in FM, which is a neurobiological disease, are of promising interest, nevertheless currently, none of them can be used to subgroup FM patients. Due to the fact that cortical and subcortical mechanisms of gait control share some cognitive functions which are involved in FM, gait markers have been proposed to evaluate and to subgroup FM patients, in clinical settings. Three out of 4 core FM symptoms are linked to gait markers. Kinesia measured by means of cranio-caudal power is correlated to pain, and could be proposed to assess pain behavior (kinesiophobia). Stride frequency, which is linked to physical component, allows the identification of a hyperkinetic subgroup. Moreover, SF has been correlated to fatigue during the 6 minute walking test. Stride regularity, which expresses the unsteadiness of gait, is correlated to cognitive dysfunction in FM. Decreased stride regularity allows the recognition of a homogeneous subgroup characterized by an increased anxiety and depression, and decreased cognitive functions. These results need further studies to be validated and so used in the daily clinical practice.

Effect of fatigue on stride pattern continuously measured by an accelerometric gait recorder in middle distance runners.

AIM: The purpose of this study was to analyze the continuous changes in stride patterns of athletes running at speed elicited VO(2max). METHODS: Six male sub-elite middle-distance runners carried out a constant track running test to exhaustion (time to exhaustion: 409+/-71 s) at their maximal aerobic speed (17.4+/-1.1 km.h(-1)). The body accelerations were measured with a triaxial accelerometer fixed at the low back. A set of variables was computed from the accelerometer output: stride frequency, stride symmetry and regularity, signal energies and impulses in each axis and the integral of the total acceleration vector. An ANOVA with repeated measures was performed to test the changes of these variables during the three times: the onset point, midway point and end point of exercise. RESULTS: The following changes were observed: the regularity index which describes the similarity of crania-caudal movements over successive strides, decreased significantly between the start and the end of the test (309.9 to 274.5; P<0.05). During the same time, the media-lateral impulse (4.69%BW.s to 5.71%BW.s; P<0.001; BW: body weight) and signal energy (1.40 G(2).s to 2.06 G(2).s; P<0.001; G=9.81 m.s(-2)) increased significantly. CONCLUSIONS: The changes in medio-lateral axis (increase of energy expenditure which is not useful for propulsion) and in the regularity index (modifications in the temporal-spatial periodicity of the running cycle) could be considered as early alterations of running pattern when the athletes got fatigued.

[Analysis of gait disorders in Parkinson's disease assessed with an accelerometer]. / Analyse des troubles de la marche par une méthode accélérométrique dans la maladie de Parkinson.

The objective of this study was to analyse stabilized gait disorders in newly diagnozed Parkinson patients using an accelerometric device, which had been previously validated for human locomotion analysis (Auvinet et al., 1999), and to compare Parkinson's gait variables with those obtained in a matched normal population (same gender, age, height and weight). The patient group included 22 subjects (women: 9, men: 13; age: 69+/-9 y; height: 164+/-9 cm; weight: 71+/-15 kg) with motor score from 4 to 59 (mean: 23.5+/-3.0). Gait analysis system included two accelerometers held over the middle of the low back by means of a semi-elastic belt, cranio-caudal and side to side accelerations were recorded at a frequency of 50 Hz. Subjects were asked to walk at their own speed along a straight 40 meter long corridor. A 20 second period of stabilized walking was used to calculate stride frequency, step symmetry, stride regularity and cranio-caudal activity (related to hypokinesia). The walking speed was measured with an electronic stop watch. Parkinson's gait was characterized by a reduction of walking velocity (p<0.0001) which was explained by reduction of stride frequency (p<0.001) and step length (p<0.001), but mainly we noticed a reduction of walking regularity (p<0.0001) and of the cranio-caudal activity (p<0.0001). These two last variables were strongly correlated to the motor score ((r=-0.59 (p<0.01); r=-0.65 (p<0.003), respectively)). In conclusion regularity and cranio-caudal activity appeared as the most interesting variables to characterize stabilized Parkinson's gait.

Fractal dimension of trabecular bone: comparison of three histomorphometric computed techniques for measuring the architectural two-dimensional complexity.

Trabecular bone has been reported as having two-dimensional (2-D) fractal characteristics at the histological level, a finding correlated with biomechanical properties. However, several fractal dimensions (D) are known and computational ways to obtain them vary considerably. This study compared three algorithms on the same series of bone biopsies, to obtain the Kolmogorov, Minkowski-Bouligand, and mass-radius fractal dimensions. The relationships with histomorphometric descriptors of the 2-D trabecular architecture were investigated. Bone biopsies were obtained from 148 osteoporotic male patients. Bone volume (BV/TV), trabecular characteristics (Tb.N, Tb.Sp, Tb.Th), strut analysis, star volumes (marrow spaces and trabeculae), inter-connectivity index, and Euler-Poincaré number were computed. The box-counting method was used to obtain the Kolmogorov dimension (D(k)), the dilatation method for the Minkowski-Bouligand dimension (D(MB)), and the sandbox for the mass-radius dimension (D(MR)) and lacunarity (L). Logarithmic relationships were observed between BV/TV and the fractal dimensions. The best correlation was obtained with D(MR) and the lowest with D(MB). Lacunarity was correlated with descriptors of the marrow cavities (ICI, star volume, Tb.Sp). Linear relationships were observed among the three fractal techniques which appeared highly correlated. A cluster analysis of all histomorphometric parameters provided a tree with three groups of descriptors: for trabeculae (Tb.Th, strut); for marrow cavities (Euler, ICI, Tb.Sp, star volume, L); and for the complexity of the network (Tb.N and the three D's). A sole fractal dimension cannot be used instead of the classic 2-D descriptors of architecture; D rather reflects the complexity of branching trabeculae. Computation time is also an important determinant when choosing one of these methods.

Accelerometric gait analysis for use in hospital outpatients.

OBJECTIVES: To provide clinicians with a quantitative human gait analysis tool suitable for routine use. METHODS: We evaluated the reproducibility, sensitivity, and specificity of gait analysis based on measurements of acceleration at a point near the center of gravity of the body. Two accelerometers held over the middle of the low back by a semi-elastic belt were used to record craniocaudal and side-to-side accelerations at a frequency of 50 Hz. Subjects were asked to walk at their normal speed to the end of a straight 40 meter-long hospital corridor and back. A 20-second period of stabilized walking was used to calculate cycle frequency, stride symmetry, and stride regularity. Symmetry and regularity were each derived from an auto-correlation coefficient; to convert their distribution from nonnormal to normal, Fisher's Z transformation was applied to the auto-coefficients for these two variables. Intraobserver reproducibility was evaluated by asking the same observer to test 16 controls on three separate occasions at two-day intervals and interobserver reproducibility by asking four different observers to each test four controls (Latin square). Specificity and sensitivity were determined by testing 139 controls and 63 patients. The 139 controls (70 women and 69 men) were divided into five age groups (third through seventh decades of life). The 63 patients had a noninflammatory musculoskeletal condition predominating on one side. ROC curves were used to determine the best cutoffs for separating normal from abnormal values. RESULTS: Neither intra- nor interobserver variability was significant (P > 0.05). Cycle frequency was significantly higher in female than in male controls (1.05 +/- 0.06 versus 0.98 +/- 0.05 cycles/s; P < 0.001). Neither symmetry nor regularity were influenced by gender in the controls; both variables were also unaffected by age, although nonsignificant decreases were found in the 61 to 70-year age group, which included only nine subjects. In the ROC curve analysis, the area under the curve was high for all three variables (frequency, 0.81 +/- 0.04; symmetry, 0.85 +/- 0.03; and regularity, 0.88 +/- 0.03), establishing that there was a good compromise between sensitivity and specificity. CONCLUSION: Our gait analysis method offers satisfactory reproducibility and is sufficiently sensitive and specific to be used by clinicians in the quantitative evaluation of gait abnormalities.

Standardisation of muscular biopsy of gluteus medius in French trotters.

Morphometric measurements were taken from 41 French trotters of various ages and both sexes. Biopsy location was determined for the dorsal compartment as being one-third of the distance from the tuber sacrale to the tuber coxae and for the ventral compartment as being one-third of the distance from the tuber coxae to the caudal Cd1-Cd2 intervertebral joint. Ten horses were biopsied at these 2 sites at a sampling depth equal to half the total depth of the compartment as measured by ultrasonography. The percentage of slow and fast myosin heavy chain fibres was measured by using an immunoenzymatic method. The depth of the dorsal and ventral compartments of the gluteus medius was significantly greater in males than in females. The depth of the ventral compartment was greater in the case of a straight hip than of a wide hip and was greater in young horses than in older horses. The ventral and the dorsal compartments were composed in the mid-portion of 81.3 and 75.6% of fast myosin heavy chains, respectively. It was concluded that the locations and sampling depths in the gluteus medius could be standardised in French trotters by taking into account anatomical references, sex, age and width of the hip.

Comparison of exercise tests in French trotters under training track, racetrack and treadmill conditions.

Standardised exercise tests were performed at 2 different tracks and on an uninclined treadmill during the same week to determine the influence of exercise surface on different measured variables such as heart rate (HR), blood lactate concentration, packed cell volume, stride frequency, stride length, gait symmetry and regularity and on different derived physiological variables such as the speed at a HR of 200 beats/min (V200), the speed at a blood lactate concentration of 4 mmol/l (V4), the speed at a maximal HR (VHRmax). Five French Trotters, age 3 years, in training for 3 months prior to the test, performed 3 exercise tests on a training track (Test 1), a racetrack (Test 2) and an uninclined treadmill (Test 3). Test 1 utilised 3 steps each of 3 min at speeds of 490, 560 and 630 m/min. Tests 2 and 3 utilised the same speeds and a fourth step in which the horse was accelerated for 30 s to speed approaching maximal. No significant differences (P < 0.05) were found for the physiological and locomotor variables between the 2 tracks. In contrast, there was a significant difference (P < 0.05) for these variables between the tracks and the treadmill, horses showing lower heart rate and blood lactate response, reduced stride frequency and increased stride length and regularity on the uninclined treadmill. We concluded that this standardised exercise test was repeatable on various tracks even when the surface and geometry vary. In contrast, both physiological and locomotor variables were different when comparing the tracks with the uninclined treadmill.

Estimation of performance potential of standardbred trotters from blood lactate concentrations measured in field conditions.

The purpose of this study was to examine the relationship between V4 (velocity which results in a blood lactate concentration of 4 mmol/l), age and racing performance of Standardbred trotters and to establish V4 normal values to select good and poor performers. The specific influence of racing (RT) and training (T1 and T2) tracks was also examined. A total of 159 horses were divided into 5 age-groups from 2 to 6 and over and performed 330 standardised exercise tests of 3 steps performed at increasing speeds. The velocity of the horses was measured with a tachometer on the sulky. Blood lactate concentrations were measured from the jugular vein after each step. For the 5 age-groups, mean V4 values increased significantly (P < 0.05) with age between 2 and 4 years. After 5 years, this increase was reduced and became nonsignificant. The highest V4 values were obtained on the racing track (RT) and the lowest on the training tracks (T1; P < 0.05). No significant difference was found between RT and T2 nor between T1 and T2. Horses were defined as good performers (GP) when finishing between the first and the fifth place in a race or poor performers (PP) when finishing lower than fifth. V4 was significantly higher for GP than for PP (P < 0.05). Normal value of V4 were established for good and poor performers taking into account the 95% confidence interval of the data. Therefore, V4 depends on age and track and can be considered an important parameter to evaluate trotters' racing potential.

Rapidly destructive disk degeneration. Report of a case documented by computed tomography and magnetic resonance imaging.

A case of rapidly destructive disk degeneration in which imaging studies were performed over a two-year period is reported. Rapidly destructive disk degeneration is a clinicopathological entity recently redefined by Revel et al.. It is analogous to conditions characterized by peripheral chondrolysis, such as rapidly destructive hip osteoarthritis. Its pathogenesis remains obscure.

Comparison of the onset and intensity of action of intramuscular meloxicam and oral meloxicam in patients with acute sciatica.

In this randomized, double-blind, double-dummy trial, 113 patients with acute sciatica were treated with a single 15-mg dose of meloxicam given intramuscularly (n = 54) or orally (n = 59). There was a significant improvement in induced pain (as measured by using the straight-leg-raising test) in both treatment groups at 60 minutes (P < 0.005), and there was a significant difference in favor of the intramuscular formulation in terms of the time to maximum improvement of induced pain (P = 0.01). Changes in spontaneous pain were similar in both treatment groups and were significant versus baseline (P < 0.01) at 30 minutes after study drug administration. Global efficacy evaluations by both the patients and investigators confirmed that meloxicam 15 mg in an intramuscular or oral formulation was effective in relieving pain in patients with acute sciatica. Meloxicam was generally well tolerated, and the local tolerability of the intramuscular injection was found to be excellent on the basis of both clinical evaluation and assessment of creatine phosphokinase levels.

Determination of the optimal treadmill slope for reproducing the same cardiac response in saddle horses as overground exercise conditions.

The purpose of this study was to define the most suitable treadmill slope for reproducing the same heart rate response as in horses being ridden on a track. Seven French saddle horses were exercised first on a level turf track and then on a treadmill. On the track the exercise test consisted of four periods of three minutes of increasing speeds at the trot and the gallop (96 to 600 m/minute). The treadmill exercise tests consisted of seven steps of increasing slope (0 to 9.6 per cent) at the trot (252 m/minute), followed, after an active recovery period at the walk with a 0 per cent slope, by five steps of increasing slope for two minutes each (0 to 6.3 per cent), at the gallop at 493 m/minute. The mean heart rate at each step of the exercise tests was measured with a heart rate recorder. On the exercise track there was a strong linear relationship (R = 0.89, P < 0.01) between heart rate and speed. The heart rate response of the horses exercised at different speeds and slopes on the treadmill was best fitted (R = 0.96, P < 0.01) by a multilinear model. The optimal treadmill slope was determined by equalizing the equations derived from the two tests: s = -0.001 V + 3.658. It was concluded that the optimal treadmill slope ranged between 3.0 and 3.7 per cent. In order to verify this result, a comparison was made between the heart rate response of the horses during the same incremental exercise test performed on the track and on the treadmill with a 3.5 per cent slope.(ABSTRACT TRUNCATED AT 250 WORDS)

Stride characteristics of overground versus treadmill locomotion in the saddle horse.

The purpose of this study was to compare the velocity-dependent changes in stride length and stride frequency of horses performing the same incremental exercise test first on a track with a rider and then on a treadmill with a 0 and 3.5% slope successively. Seven French saddle horses undertook the exercise test which consisted of 5 stages of increasing speed for 3 min each with 1 min rest between each stage (1.6, 4.2, 8.3, 9.2 and 10 m/s). The horses were recorded by use of a video camera, and the tapes were analysed with regard to gait parameters. At 1.6, 8.3, 9.2 and 10 m/s, stride frequencies were significantly (p < 0.01) greater on the track than on the treadmill. At the walk, stride length was significantly (p < 0.01) shorter on the track than on the treadmill. There were strong linear relationships between stride length and speed in all experimental conditions (R2 > 0.96). The comparison of the regression coefficients revealed significant differences (p < 0.01) between track and treadmill locomotion; stride length was longer on both the horizontal and inclined treadmill than on the track. The incline of the treadmill did not significantly (p > 0.01) influence stride parameters.

[Bone density in idiopathic hypercalciuria in men. Study by dual photon absorptiometry, X-ray computed tomography and histomorphometry]. / La densité osseuse dans l'hypercalciurie idiopathique chez l'homme. Etude par absorptiométrie biphotonique, tomodensitométrie et histomorphométrie.

Lumbar bone mineral density (BMD) of the L3 vertebra was evaluated by double photon absorptiometry or tomodensitometry (TDM) in 55 hypercalciuric individuals in two separate studies. In the first, in a department of nephrology, 29 lithiasis patients were studied by TDM of L3. By this technique, trabecular density was 75 +/- 23% of normal. It was lower in the 17 patients in whom hypercalciuria persisted after calcium restriction (66 +/- 15% of normal and below the "fracture threshold" in 9 cases) than in the 12 patients in whom it disappeared after the prescription of such a diet (88 +/- 26%, below the "fracture threshold" in 3 cases), this difference being significant (p less than 0.01). In another 26 patients, seen in a department of rheumatology, three of whom had osteoporosis with vertebral fracture, density was measured in 21 cases by double photon absorptiometry (mean Z score -1.9 +/- 1.0) and in 5 cases by TDM (mean BMD of L3 69 +/- 21% of normal). Mean iliac trabecular volume, measured in 8 cases only, was 70 +/- 25% of normal and was below the "fracture threshold" in 3 cases. Comparison of the two study groups was not possible because of differences in recruitment and methods of investigation. These two studies nevertheless show the existence of significant vertebral bone rarefaction during hypercalciuria in the young man. Confirmed and quantified in patients in whom the metabolic disturbance was discovered as a result of radiological abnormalities, this quantitative abnormality was also seen in patients in whom hypercalciurie was found because of renal lithiasis.(ABSTRACT TRUNCATED AT 250 WORDS)

[Dibekacin in the treatment of septicemia]. / La dibékacine dans le traitement des septicémies.

During an open multicentric trial (17 centers), we have treated 62 septicemia by dibekacin, alone or associated with other antibacterial drugs. Taking into account the degree of severity of these patients, the results are considered satisfactory in 47 patients. 15 failures were noted (including 9 deaths). General and local tolerance were good, in spite of the duration of treatment.