Jean Denis Laredo

Prognostic value of early computed tomography in radiculopathy due to lumbar intervertebral disk herniation. A prospective study

OBJECTIVE To prospectively evaluate the relationship between the early computerized tomography (CT) features of disk herniation and the clinical outcome in patients with recent-onset sciatic or femoral neuralgia treated conservatively. Early CT is often used, despite the absence of data on usefulness for predicting outcomes. METHODS Of 78 patients with sciatica or femoral neuralgia of less than 1 months duration, presumably due to a disk herniation, 75 were found by CT to have a disk herniation at the expected level. All patients were treated conservatively. The 60 patients who were reassessed clinically after 3 months were included in the study. Based on the results of the clinical assessment, the patients were classified as having a good outcome (complete or partial recovery) or a poor outcome. CT findings were compared in these two groups. RESULTS None of the features of disk herniation studied on the CT scans were significantly correlated with the clinical outcome. A larger herniation or presence of a free fragment was more common in the good outcome group, but the differences were not statistically significant (P= 0.07). CONCLUSION In this study, early CT scan did not predict the clinical outcome of patients with nerve root pain from lumbar disk herniation. None of the CT criteria was associated with a poor clinical outcome. Early CT scan has no prognostic value in this setting.

Muscle magnetic resonance imaging sensitivity does not decrease in chronic, mild, or proximal lower limb neuropathies

Introduction: Muscle magnetic resonance imaging (MRI) is an innovative tool for exploring focal neuropathies. However, its usefulness in mild, proximal, or chronic lesions, when electromyography (EMG), the current “gold standard” sensitivity is inadequate, has yet to be studied. Methods: Clinical, MRI, and EMG examinations were performed in 113 muscles of 17 consecutive patients with clinically diagnosed lower limb focal neuropathies. The sensitivity and specificity of MRI and EMG were evaluated in relation to disease duration, severity, and anatomical location. Results: Muscle MRI was highly sensitive for the detection of denervated muscle, and, unlike EMG, its sensitivity did not decrease regardless of the anatomical location, duration, or severity of the neuropathy. Five MRI false positives were noted, including three in the thigh muscles. Conclusions: Muscle MRI is an alternative tool to EMG in proximal, mild, or chronic clinical diagnoses of lower limb focal neuropathies. However, it also seems prone to false‐positive results, particularly in proximal muscles. Muscle Nerve, 2012

High resolution volume quantification of the knee joint space based on a semi-automatic segmentation of computed tomography images

Osteoarthritis (OA) is a joint disorder that causes pain, stiffness and decreased mobility. Knee OA presents the greatest morbidity. The main characteristic of OA is the cartilage loss inducing joint space (JS) narrowing. Usually, the progression of OA is monitored by the minimum JS measurement on 2D X-rays images. New dedicated systems based on cone beam computed tomography, providing enough image quality and with favourable dose characteristics are under development. With these new systems, it would be possible to follow the 3D JS changes. High resolution peripheral computed tomography (HR-pQCT) usually used for assessing the trabecular and cortical bone mineral density have been performed on specimen knees with an isotropic voxel of 82 microns. We present here a new semi-automatic segmentation method to measure the 3D local variations of JS. The experiments have been done on HR-pQCT data set and the results have been extended to other computed tomography images with low resolution and/or with cone beam geometry.

Serous transformation of marrow of distal femoral epiphysis in a patient with congenital general lipodystrophy and spondylarthritis

Joint Bone Spine - In Press.Proof corrected by the author Available online since mardi 11 juin 2013

Muscle MRI STIR signal intensity and atrophy are correlated to focal lower limb neuropathy severity

AbstractObjectivesThe objective is to determine if muscle MRI is useful for assessing neuropathy severity.MethodsClinical, MRI and electromyography (EMG) examinations were performed in 17 patients with focal lower limb neuropathies. MRI Short Tau Inversion Recovery (STIR) signal intensity, amyotrophy, and muscle fatty infiltration measured after T1-weighted image acquisition, EMG spontaneous activity (SA), and maximal voluntary contraction (MVC) were graded using semiquantitative scores and quantitative scores for STIR signal intensity and were correlated to the Medical Research Council (MRC) score for testing muscle strength. Within this population, subgroups were selected according to severity (mild versus severe), duration (subacute versus chronic), and topography (distal versus proximal) of the neuropathy.ResultsEMG SA and MVC MRI amyotrophy and quantitative scoring of muscle STIR intensity were correlated with the MRC score. Moreover, MRI amyotrophy was significantly increased in severe, chronic, and proximal neuropathies along with fatty infiltration in chronic lesions.ConclusionsMuscle MRI atrophy and quantitative evaluation of signal intensity were correlated to MRC score in our study. Semiquantitative evaluation of muscle STIR signal was sensitive enough for detection of topography of the nerve lesion but was not suitable to assess severity. Muscle MRI could support EMG in chronic and proximal neuropathy, which showed poor sensitivity in these patients.Key Points• Muscle MRI is an interesting alternative tool to electromyography in diagnosing neuropathies. • Muscle MRI STIR signal intensity is correlated to muscle strength. • Muscle MRI amyotrophy is correlated to muscle strength as is electromyography. • MRI amyotrophy is significantly increased in severe, chronic, and proximal neuropathies.

Valeur pronostique du scanner précoce chez les patients souffrant de radiculalgie commune par hernie discale lombaire. Étude prospective

Resume But de l’etude. – Recherche prospective d’une relation entre l’evolution d’une lomboradiculalgie commune par hernie discale et les resultats d’un scanner realise precocement. De nombreux patients souffrant d’une sciatique ont un scanner lombaire precoce sans que le benefice medical de cette pratique ait ete evalue. Patients et methodes. – Soixante-dix-huit patients ayant une cruralgie ou une sciatique commune depuis moins d’un mois ont eu un scanner lombaire. L’examen a montre une hernie discale concordante chez 75 d’entre eux. Ces 75 patients ont ete traites medicalement. Soixante d’entre eux ont pu etre reexamines a 3 mois et donc repartis en deux groupes selon leur etat clinique, le groupe 1 correspondant a une amelioration (guerison complete ou partielle) et le groupe 2 a l’echec du traitement medical. Les resultats du scanner ont ensuite ete compares dans les deux groupes. Resultats. – Aucune caracteristique morphologique de la hernie discale n’est significativement correlee a l’evolution clinique des patients revus trois mois apres le debut des symptomes. La migration en hauteur de la hernie discale etait en moyenne plus ample chez les malades ameliores, mais ce resultat n’est pas significatif ( p = 0,07). Conclusion. – Dans cette etude, la realisation precoce d’un scanner lombaire ne permet pas de predire l’evolution d’une lomboradiculalgie par hernie discale. Aucun critere scanographique ne caracterise les patients qui ont eu une evolution defavorable, critere qui aurait permis de les orienter rapidement vers un traitement radical. Nous concluons que la realisation precoce d’un scanner lombaire n’a aucun interet pronostique dans la lomboradiculalgie commune.