The MR scans in SS show a rather distinctive pattern of supratentorial white matter lesions that always involve the corpus callosum. There is often deep gray matter, posterior fossa involvement, and frequent parenchymal with occasional leptomeningeal enhancement. The central callosal lesions differ from those in demyelinating disease, and should support the diagnosis of SS in patients with at least two of the three features of the clinical triad.

Among clinical measures, contrast letter acuity (Sloan charts) and contrast sensitivity (Pelli-Robson chart) demonstrate the greatest capacity to identify binocular visual dysfunction in MS. Sloan chart testing also captures unique aspects of neurologic dysfunction not captured by current EDSS or MSFC components, making it a strong candidate visual function test for the MSFC.

Magnetic resonance (MR) images--both nonenhanced and enhanced with gadolinium DTPA/dimeglumine (Gd)--were compared with high-iodine (88.1 g I) computed tomographic (HICT) scans in demonstrating lesions in 15 patients known to have multiple sclerosis (MS). T1-weighted, mixed (T1, proton density, and T2), and T2-weighted MR pulse sequences were used. More than 20 lesions in each of 14 patients were demonstrated by pre-Gd mixed images and T2WI. Nine patients had clinical symptoms of active disease. Gd-enhanced T1WI showed at least one lesion that appeared to correspond with newly reported symptoms or signs. In addition, three clinically stable patients showed enhancement. Enhancement was best seen on 3-minute T1WI. HICT scans showed enhancement in four of the nine patients with active disease and in none of five clinically stable patients. Gd-enhanced MR imaging appears to be more sensitive than HICT in the detection of the transient abnormalities of the blood-brain barrier that occur in patients with active MS and appears capable of distinguishing active lesions that may correspond to the anatomic regions responsible for abnormal clinical findings.

Abstract-Advancements in imaging technologies and newly evolving treatments offer the promise of more effective management strategies for MS. Until recently, confirmation of the diagnosis of MS has generally required the demonstration of clinical activity that is disseminated in both time and space. Nevertheless, with the advent of MRI techniques, occult disease activity can be demonstrated in 50 to 80% of patients at the time of the first clinical presentation. Prospective studies have shown that the presence of such lesions predicts future conversion to clinically definite (CD) MS. Indeed, in a young to middle-aged adult with a clinically isolated syndrome (CIS), once alternative diagnoses are excluded at baseline, the finding of three or more white matter lesions on a T2-weighted MRI scan (especially if one of these lesions is located in the periventricular region) is a very sensitive predictor (Ͼ80%) of the subsequent development of CDMS within the next 7 to 10 years. Moreover, the presence of two or more gadolinium (Gd)-enhancing lesions at baseline and the appearance of either new T2 lesions or new Gd enhancement on follow-up scans are also highly predictive of the subsequent development of CDMS in the near term. By contrast, normal results on MRI at the time of clinical presentation makes the future development of CDMS considerably less likely.