Neuroimaging of multiple sclerosis has made many relevant discoveries on the the natural history of multiple sclerosis, nowadays very well known. Patients have neurological relapses followed by remissisons for a decade (adults) or 2 decades ( children), when they develop neurological progression, usually consisting of progressive paraparesis. The cause of this progression has been debated. One possibility is cummulative load of axonal and neuronal death; another is the load of spinal cord lesions.
It was only some 10 years ago the magnetic ressonce (MR) images of the spinal cord of patients with multiple sclerosis became clinically as relevant as those of the brain. Even more recently, in the past 5 years, images of the optic nerves also became clinically useful. I mean clinically relevant and useful because it was in the last decade or so that these lesions began to correlate well, and then to be more apparent, on imaging as compared to the clinical examination performed by trained neurologists.
Mario A Rocca et al. Neurology 2019; 93:e1852-e1866
These authors looked at 179 controls and at 435 patients with MS, including patients with isolated syndrome, relapsing-remitting and progressive disease. The study was carried out between 2010-2016 in Germany, Netherland, Switzeland, Italy, Spain and UK. MRIs with special attention to T1 images of the entire cervical cord. They found that cervical cord cross sectional area decreased in all patients except those with isolated syndrome when scans were obtained one year after the first. The rate of cervical cord atrophy was faster in patients with relapsing remitting MS and in those with clinically worsening disease. Primary progressive and progressive MS was poorly represented in the study. Neuroimaging in multiple sclerosis of the progressive form still waits for definitive studies.
This lack of studies of neuroimaging in multiple sclerosis of the progressive form was partly improved by another study of 38 patients aged 54 years ( mean), who showed that a single critical cervical cord lesion may cause progressive unilateral motor progression. These were lesions associated with focal atrophy, with a prominent size and appropriate localization, that is, in the cervical cord lateral column, medular pyramid, cerebral peduncle or internal capsule,
Sechi et al Neurology 2019, 93:e628-e634
Yeh and Fox. Neurology 2019, 93:283-284
Carried out at the May Clinic on patients seen between 1996 and 2017, the study had methodological details that allowed the authors to conclude that a single critical lesion may be directly responsible for progressive motor déficits. In all patients, there was a clear tendency for lesions to be in the cervical cord. Moreover, they found that the single lesion was always in the spinal cord in the case of progressive myelopathy, which only confirms old fashioned clinical neurology based on the physical examination, but is nonetheless of critical importance. Althoug a very small study of a highly selected population, it does demonstrate what was expected from clinical neurology.
Dr Paulo Bittencourt