J.-P. Pruvo

Devic's neuromyelitis optica: clinical, laboratory, MRI and outcome profile

Devics neuromyelitis optica (NMO) associates optic neuritis and myelitis without any other neurological signs. Many patients with NMO may be diagnosed as having multiple sclerosis (MS), optic neuritis and myelitis being the inaugural symptom in 20% and 5% of MS cases, respectively. The aim of our study was to compare a new NMO cohort with recent studies and to try to determine the place of NMO in the spectrum of MS. We retrospectively studied 13 patients with a complete diagnostic workup for NMO. We compared our data with the most recent studies on NMO and with the criteria proposed by Wingerchuck et al. [Neurology 53 (1999) 1107]. We also determined whether these patients fulfilled the diagnostic criteria for MS. Thirteen patients (10 women and three men, with a mean age of 37.4 years) were included in the study. We found similar results to previously published data, except for an association with vasculitis in 38% of our cases. All but three of the patients fulfilled the clinical criteria for MS and two patients fulfilled both clinical and MRI criteria for MS. However, if we applied more restrictive criteria concerning spinal cord and brain MRI and CSF, none of our NMO patients fulfilled the MS diagnostic criteria. NMO might therefore be differentiated from MS by the application of more stringent criteria. Furthermore, all NMO patients should be investigated for vasculitis, even those with no history of systemic disease.

Prospective study of patients presenting with acute partial transverse myelopathy.

Abstract.Background:The clinical and radiological characteristics of myelopathy in multiple sclerosis (MS) are relatively well known. Nevertheless, it remains difficult for the clinician to ascertain conversion to MS after a first episode of acute partial transverse myelopathy (APTM).Objective:The aims of this study were to define predictive factors for conversion to clinically definite MS after an APTM and to define predictive factors for disease severity.Patients and methods:Between 1994 and 2001, we prospectively included 55 patients presenting with a first episode of APTM. Three patients were lost during the follow-up. We evaluated clinical signs, spinal cord and brain MRI, cerebrospinal fluid (CSF) and visual evoked potentials on admission.After a mean followup of 35 months (range 12–86), we evaluated the diagnosis and, among the MS group, the severity of the disease.Results:Of the 52 APTM patients who completed the study, 30 became clinically definite MS. The predictive factors for conversion to MS were: initial sensory symptoms, latero-posterior spinal cord lesion, abnormal brain MRI and oligoclonal bands in CSF. In the MS group, the number of spinal cord lesions on MRI was the only predictive factor for a poor outcome, being statistically correlated with a higher number of relapses.Conclusion:On the basis of our results, we propose that, in patients with APTM, sensory symptoms, oligoclonal bands and brain MRI are predictive factors for subsequent conversion to clinically definite MS and that within the latter patients the number of spinal cord lesions on MRI is the only predictive factor for a poor outcome.

Added Value of High-Resolution MR Imaging in the Diagnosis of Vertebral Artery Dissection

BACKROUND AND PURPOSE: The optimal imaging method for the diagnosis of VAD remains undefined. Our aim was to evaluate the added value of HR-MR imaging for the diagnosis of VAD. MATERIALS AND METHODS: We retrospectively extracted 35 consecutive patients suspected of having acute VAD who had the following: 1) a focal lumen abnormality of the VA on CE-MRA, 2) HR-MR imaging during the initial hospital stay, and 3) clinical and imaging follow-up within 6 months. Two neurologists classified patients as either VAD (group A) or non-VAD (group B) by reviewing all the available data at hospital discharge, except HR-MR imaging data. On HR-MR imaging, 2 radiologists searched for signs of acute VAD. The 2 classifications were compared. In case of discordance, CE-MRA follow-up and axial fat-suppressed T1WI, used to obtain supportive evidence for or against VAD, were considered as the standard of reference. RESULTS: In 4/18 patients in group A, HR-MR imaging did not demonstrate any signs of acute VAD and perivertebral signal-intensity changes were attributed to venous plexus, with an unchanged lumen on follow-up. In 4/17 patients in group B, HR-MRI demonstrated a mural hematoma, with lumen normalization on follow-up CE-MRA. CONCLUSIONS: Our results encourage the use of HR-MR imaging as a second-line diagnostic tool in the event of suspicion of acute VAD and doubtful findings on standard imaging.

Pupillary disturbances in multiple sclerosis: correlation with MRI findings

UNLABELLED Autonomic nervous system disturbances such as pupillary abnormalities have rarely been evaluated in multiple sclerosis (MS). However, pupillary impairment is not uncommon in MS and its origin is still unclear. The aim of this study was to investigate pupillary disturbances in MS and to try to correlate pupillary defects with spinal cord and brainstem magnetic resonance imaging (MRI) findings. We prospectively studied 45 MS patients and 30 normal subjects. METHODS The pupillary contraction latency and the amplitude of contraction were recorded by pupillometry. We also determined afferent and efferent pathway defects by comparing the direct and consensual pupillary reflexes. We evaluated brainstem and spinal cord demyelinating lesions and spinal cord cross-sectional area on MRI. At least one pupillometric parameters were significantly impaired in 60% of patients and in none of the controls. We did not find any correlation between pupillary defect and demyelinating lesions on MRI. The most frequent abnormality was efferent pathway shift and this was correlated with spinal cord atrophy (P<0.02). These results confirm that the autonomic nervous system, and especially pupillary function, is frequently impaired in MS. The parasympathetic system is most commonly affected and this is most likely linked to axonal loss (demonstrated by spinal cord atrophy) rather than to demyelinating lesions.

Brain Magnetic Susceptibility Changes in Patients with Natalizumab-Associated Progressive Multifocal Leukoencephalopathy

These authors retrospectively evaluated 12 patients with natalizumab–progressive multifocal leukoencephalopathy (PML), 5 with PML from other causes, and 55 patients with MS without progressive PML for comparison. They observed T2* or SWI signal abnormalities at the chronic stage in all patients with PML, but in patients without PML no areas of low SWI signal intensity were detected. PML—related to natalizumab or not—induces brain susceptibility changes within U-fibers or deep gray matter that are visible on T2* or SWI and potentially explained by iron deposition. SUMMARY: We investigated the brain magnetic susceptibility changes induced by natalizumab-associated progressive multifocal leukoencephalopathy. We retrospectively included 12 patients with natalizumab–progressive multifocal leukoencephalopathy, 5 with progressive multifocal leukoencephalopathy from other causes, and 55 patients with MS without progressive multifocal leukoencephalopathy for comparison. MR imaging examinations included T2* or SWI sequences in patients with progressive multifocal leukoencephalopathy (86 examinations) and SWI in all patients with MS without progressive multifocal leukoencephalopathy. Signal abnormalities on T2* and SWI were defined as low signal intensity within the cortex and/or U-fibers and the basal ganglia. We observed T2* or SWI signal abnormalities at the chronic stage in all patients with progressive multifocal leukoencephalopathy, whereas no area of low SWI signal intensity was detected in patients without progressive multifocal leukoencephalopathy. Among the 8 patients with asymptomatic natalizumab–progressive multifocal leukoencephalopathy, susceptibility changes were observed in 6 (75%). The basal ganglia adjacent to progressive multifocal leukoencephalopathy lesions systematically appeared hypointense by using T2* and/or SWI. Brain magnetic susceptibility changes may be explained by the increased iron deposition and constitute a useful tool for the diagnosis of progressive multifocal leukoencephalopathy.

Is It Possible to Recognize Cervical Artery Dissection on Stroke Brain MR Imaging? A Matched Case-Control Study

Arterial dissections are not uncommonly found in patients with acute stroke. Do we need a special protocol or can these be diagnosed on the standard brain MR imaging study? In 103 consecutive patients, the authors were able to identify 77 in whom the fat-suppressed T1 images showed mural internal carotid artery clot. These studies were retrospectively reviewed by 2 blinded observers who looked at 5 different sequences from the 77 patients and 77 controls. Seventy-seven percent of patients and 95% of controls were correctly classified. Thus, initial brain MR imaging can correctly suggest cervical arterial dissection in more than two-thirds of cases. This may have practical implications in patients with stroke and delayed cervical MR angiography or in those who are not initially suspected of having CAD. BACKGROUND AND PURPOSE: Extracranial CAD accounts for nearly 20% of cases of stroke in young adults. The mural hematoma frequently extends cranially to the petrous carotid segment in cCAD or is distally located in vCAD. We hypothesized that standard brain MR imaging could allow the early detection of CAD of the upper portion of carotid and vertebral arteries. MATERIALS AND METHODS: Our prospectively maintained stroke data base was retrospectively queried to identify all patients with the final diagnosis of CAD. In the 103 consecutive patients studied, analysis of cervical fat-suppressed T1-weighted sequences demonstrated that the mural hematoma was located in the FOV of brain MR imaging in 77 patients. Subsequent to enrollment of a patient, a control patient was extracted from the same data base, within a similar categories for sex, age, NIHSS score, and stroke on DWI. Two blinded observers independently reviewed the 5 brain MR sequences of each examination and determined whether a CAD was present. RESULTS: Fifty-nine of the 77 patients with CAD (76.6%) and 73 of the 77 patients without CAD (94.8%) were correctly classified. Brain MR imaging demonstrated cCAD more frequently than vCAD in 54/58 (93.1%) and 5/19 (26.3%) patients, respectively, (P < .0001). CONCLUSIONS: Initial brain MR imaging can correctly suggest CAD in more than two-thirds of patients. This may have practical implications in patients with stroke with delayed cervical MRA or in those who are not initially suspected of having CAD.

Accuracy of Postcontrast 3D Turbo Spin-Echo MR Sequence for the Detection of Enhanced Inflammatory Lesions in Patients with Multiple Sclerosis

BACKGROUND AND PURPOSE: Therapeutic strategies for patients with MS partly rely on contrast-enhanced MR imaging. Our aim was to assess the diagnostic performance of 3D turbo spin-echo MR imaging with variable refocusing flip angles at 3T for the detection of enhanced inflammatory lesions in patients with multiple sclerosis. MATERIALS AND METHODS: Fifty-six patients with MS were prospectively investigated by using postcontrast T1-weighted axial 2D spin-echo and 3D TSE MR images. The order in which both sequences were performed was randomized. Axial reformats from 3D T1 TSE were generated to match the 2D spin-echo images. The reference standard was defined by using clinical data and all MR images available. Three separate sets of MR images (2D spin-echo images, axial reformats, and multiplanar images from 3D TSE sequences) were examined in a blinded fashion by 2 neuroradiologists separately for the detection of enhanced MS lesions. Image artifacts and contrast were evaluated. RESULTS: No artifacts related to vascular pulsation were observed on 3D TSE images, whereas image artifacts were demonstrated on 2D spin-echo images in 41 patients. One hundred twelve enhanced MS lesions were identified in 19 patients. Sixty-four lesions were correctly diagnosed by using 2D spin-echo images; 90, by using 3D TSE axial reformatted views; and 106, by using multiplanar analysis of the 3D TSE sequence. Multiplanar analysis was 94.7% sensitive and 100% specific for the diagnosis of patients with at least 1 enhanced lesion. Contrast of enhanced MS lesions was significantly improved by using the 3D TSE sequence (P < .011). CONCLUSIONS: The 3D TSE sequence with multiplanar analysis is a useful tool for the detection of enhanced MS lesions.

Pulse-Triggered DTI Sequence with Reduced FOV and Coronal Acquisition at 3T for the Assessment of the Cervical Spinal Cord in Patients with Myelitis

BACKGROUND AND PURPOSE: DTI is a promising technique for imaging of the spinal cord, but the technique has susceptibility-induced artifacts. We evaluated a pulse-triggered DTI sequence with an rFOV technique and coronal acquisition for the assessment of the cervical spinal cord in patients with myelitis at 3T. MATERIALS AND METHODS: A rFOV acquisition was established by a noncoplanar application of the excitation and the refocusing pulse in conjunction with outer volume suppression. The DTI sequence was performed in the coronal plane in 12 healthy volunteers and 40 consecutive patients with myelitis. Probabilistic tractography of the posterior and lateral funiculi was performed from the C1 to C7 levels. FA, MD, aD, rD, and ratios of aD and rD were measured. RESULTS: In healthy volunteers, mean DTI indices within the whole-fiber pathways were the following: FA = 0.61, MD = 1.17 × 10−3 mm2/s, aD = 1.96 × 10−3 mm2/s, rD = 0.77 × 10−3 mm2/s, and ratios of aD and rD = 2.5. Comparison of healthy controls and patients with myelitis identified statistically significant differences for all DTI parameters. Different patterns of myelitis, including spinal cord atrophy and active inflammatory lesions, were recognized. There was a significant correlation between clinical severity and DTI parameters. CONCLUSIONS: The present work introduces a new approach for DTI of the cervical spinal cord at 3T, enabling a quantitative follow-up of patients with myelitis.

Tuberculose neuro-méningée : apport de la méthode par amplification génique dans le diagnostic

Resume Les manifestations neurologiques de la tuberculose sont rares, notamment chez les patients immunocompetents. La variete des signes cliniques et radiologiques ainsi que les difficultes diagnostiques entrainent frequemment un retard de prise en charge. L’objectif de ce travail a ete d’etudier la presentation clinique et paraclinique ainsi que le profil evolutif de la tuberculose neuro-meningee chez 11 patients immunocompetents. Tous les patients ont beneficie d’au moins une ponction lombaire avec recherche de bacille tuberculeux par Polymerase Chain Reaction (PCR), d’une IRM et ont ete suivis au moins un an. Six hommes et 5 femmes âges en moyenne de 46,5 ans, caucasiens pour 6 d’entre eux, ont presente un syndrome meninge dans 9 cas avec signes neurologiques focaux pour 4 d’entre eux et un tableau medullaire dans 2 cas. Le LCR etait anormal dans 82 p. 100 des cas, montrant une hyperproteinorrachie (73 p. 100), une hypercytose (73 p. 100), une hypoglycorrachie (45 p. 100), ou une hypochlorurorrachie (36 p. 100). Le meilleur outil diagnostique etait la PCR-BK (positive dans 45 p. 100 des cas), la recherche de BK par culture n’etant positive que dans 2 cas (18 p. 100). Seuls 2 patients presentaient une atteinte pulmonaire clinique associee. L’IRM etait anormale dans 64 p. 100 des cas montrant des tuberculomes, une arachnoidite, des lesions infiltrantes ou des lesions medullaires. L’evolution fut favorable sauf pour 2 patients (un deces et paraplegie) en raison d’un retard diagnostique. La tuberculose neuro-meningee est une affection extremement heterogene dans sa presentation clinique et radiologique. Le meilleur outil diagnostique semble etre la recherche de BK par methode PCR. L’evolution est le plus souvent favorable si la prise en charge et le diagnostic sont rapides.

Cardiac repolarization abnormalities in multiple sclerosis: Spinal cord MRI correlates

Ventricular repolarization dysfunction has recently been reported in multiple sclerosis (MS). We evaluated ventricular repolarization dysfunction in 52 MS patients and looked for a relationship between corrected QT (QTc) abnormalities (i.e., abnormalities of QT intervals corrected for rate) and spinal cord magnetic resonance imaging (MRI) findings. QTc intervals were increased in MS patients compared with controls (P < 0.01) and were correlated with a reduction of spinal cord area (P < 0.01). QTc abnormalities in MS were thus associated with axonal loss, reflected by spinal cord atrophy, rather than demyelination.