Corpus callosum volume and interhemispheric transfer in multiple sclerosis.

BACKGROUND: The corpus callosum (CC) is frequently compromised in patients with multiple sclerosis (MS). Structural and functional measurements of the CC may be useful to monitor the progression of the disease. The aim of this pilot study was to determine if bimanual tactile temporal thresholds correlates with CC volume. A tactile temporal threshold is the longest temporal interval that separates the onsets of two tactile stimuli when they are judged by the observer as simultaneous. Judgments to bimanual stimulations require interhemispheric transfer via the CC. METHODS: Thresholds were examined in MS patients and matched controls. Magnetic resonance (MR) images were acquired on a 3T MR system within 48 hours of clinical assessment and measurement of thresholds. RESULTS: Corpus callosum volume was assessed by using a semiautomatic livewire algorithm. The CC volume was smaller (by 21% on average, p < 0.01) and thresholds were higher (by 49% on average, p < 0.03) in MS patients when compared to controls. A significant correlation (r = -0.66, p = 0.01) between CC volume and thresholds emerged for the MS patients. CONCLUSION: Measuring treatment benefits of neuroprotective and repair therapies is a well recognized challenge in MS research. The overall findings of this study suggest that these measurements, which involve the transfer of information interhemispherically via the CC, may be promising outcome measures that warrant further scientific exploration to develop a model to measure recovery.

Failure to develop multiple sclerosis in patients with neurologic symptoms without objective evidence.

BACKGROUND: Many patients referred to multiple sclerosis (MS) centers with symptoms suggestive of MS are found to have normal neurologic examinations, normal or non-specific brain magnetic resonance imaging (MRI) scan findings, and normal cerebrospinal fluid (CSF). Persistent symptoms often lead to multiple consultations and repeated diagnostic investigations. We performed a study to evaluate the diagnostic utility of repeated evaluations in patients with normal initial assessments and persistent neurologic symptoms. METHODS: 143 patients were evaluated initially and 109 returned for a second evaluation after a mean interval of 4.4 years. RESULTS: All 143 patients had normal initial examinations, brain MRI scans, screening blood tests, and CSF studies. Spinal cord imaging was normal in all patients tested (cervical cord, n = 126; 88.1%; thoracic cord, n = 58; 40.6%). Evoked potential studies were abnormal in a small percentage of patients: visual evoked potentials, VEP (8.1%), somatosensory evoked potentials, SSEP (4.9%), and brainstem auditory evoked potentials, BAEP (2.8%). All follow-up patients (n = 109) had normal examinations and MRI scans. Repeat CSF studies (n = 35; 32.1%) and spinal cord imaging (cervical cord n = 57; 52.3%; thoracic cord n = 32; 29.4%) were normal in all follow-up patients tested. No patients at initial presentation or at follow-up fulfilled diagnostic criteria for MS. PATIENTS: and clinicians may be reassured that persistent neurologic symptoms in the absence of objective clinical evidence do not lead to the development of MS. Costly serial investigations should be carefully considered, particularly in the presence of normal neurologic examination at follow-up.

Oral prednisone taper following intravenous steroids fails to improve disability or recovery from relapses in multiple sclerosis.

BACKGROUND: A short course of intravenous methylprednisolone (IVMP) followed by oral prednisone taper (OPT) is often used for the treatment of relapses in multiple sclerosis (MS). We examined the effect of IVMP plus OPT compared with IVMP only on neurologic disability 1 year after treatment of a relapse in patients with relapsing-remitting multiple sclerosis. METHODS: Two hundred eighty-five consecutive relapses were analyzed in a retrospective fashion. One hundred fifty-two patients with a total of 171 relapses received IVMP plus an OPT at the time of relapse whilst 112 patients who experienced 114 relapses received IVMP without OPT. RESULTS: There was no difference between the two groups in the baseline characteristics as well as the mean or categorical EDSS at baseline, at the time of relapse confirmation, and at months 3, 6 and 12 after relapse confirmation. CONCLUSION: Our observations suggest that OPT following treatment with IVMP for an MS relapse does not lead to improved neurologic outcome after 12 months compared with treatment with IVMP only. Moreover, our findings raise concerns regarding the common practice of using OPT following IVMP. Further studies are indicated to validate our findings and minimize exposure to systemic corticosteroids, well known for systemic toxicity.

Deep grey matter "black T2" on 3 tesla magnetic resonance imaging correlates with disability in multiple sclerosis.

T2 hypointensity (black T2, BT2) in the deep grey matter of multiple sclerosis (MS) patients correlate weakly with disability at 1.5 T. BT2 is likely to be caused by abnormal iron deposition. We compared the correlation between disability and deep grey matter BT2 measured on 3 T MRI and on 1.5 T MRI in 17 MS patients. We observed a significant correlation between expanded disability status scale and signal intensity on 3 T MRI in the globus pallidus and the caudate nucleus (r = -0.5, P < 0.05). BT2 at 3 T may be a useful MRI measure associated with disability in MS and warrants further study.

The clinical response to minocycline in multiple sclerosis is accompanied by beneficial immune changes: a pilot study.

Minocycline has immunomodulatory and neuroprotective activities in vitro and in an animal model of multiple sclerosis (MS). We have previously reported that minocycline decreased gadolinium-enhancing activity over six months in a small trial of patients with active relapsing-remitting MS (RRMS). Here we report the impact of oral minocycline on clinical and magnetic resonance imaging (MRI) outcomes and serum immune molecules in this cohort over 24 months of open-label minocycline treatment. Despite a moderately high pretreatment annualized relapse rate (1.3/year pre-enrolment; 1.2/year during a three-month baseline period) prior to treatment, no relapses occurred between months 6 and 24. Also, despite very active MRI activity pretreatment (19/40 scans had gadolinium-enhancing activity during a three-month run-in), the only patient with gadolinium-enhancing lesions on MRI at 12 and 24 months was on half-dose minocycline. Levels of the p40 subunit of interleukin (IL)-12, which at high levels might antagonize the proinflammatory IL-12 receptor, were elevated over 18 months of treatment, as were levels of soluble vascular cell adhesion molecule-1. The activity of matrix metalloproteinase-9 was decreased by treatment. Thus, clinical and MRI outcomes are supported by systemic immunological changes and call for further investigation of minocycline in MS.

[Vacuolar leucoencephalopathy induced by heroin: 4 cases]. / La leucoencéphalopathie vacuolaire induite par l'héroïne: 4 cas.

We report 4 cases of toxic leucoencephalopathy after heroin inhalation. The clinical features, which usually occur some days or even longer after the last heroin consumption, are dominated by a cerebellar syndrome. The cerebellar hemispheres are almost always affected; the cerebral hemispheres, the cerebellar peduncles and the pyramidal tract may be affected. Vacuolar demyelination is the morphological substract of the lesions, which are symmmetrical, not contrast enhancing, hypodense on CT scan and hyperintense on T2-weighted MRI. The pathophysiology is unknown and seems different from post-anoxic leucoencephalopathy. The disease is usually progressive leading sometimes to death, but some cases show slow recovery.