The researchers seem to have found a new classification: progressive solitary sclerosis. A person can have one demyelinating lesion according to MRI results and yet have symptoms and signs of a progressive demyelinating disease, which they're calling progressive solitary sclerosis.
From PubMed, October 20, 2016:
Neurology. 2016 Oct 18;87(16):1713-1719.
Progressive solitary sclerosis: Gradual motor impairment from a single CNS demyelinating lesion
Keegan BM1, Kaufmann TJ2, Weinshenker BG2, Kantarci OH2, Schmalstieg WF2, Paz Soldan MM2, Flanagan EP2.
Author information
1From the Departments of Neurology (B.M.K., O.H.K., E.P.F.) and Neuroradiology (T.J.K., B.G.W.), Mayo Clinic, Rochester; Department of Neurology (W.F.S.), University of Minnesota, Minneapolis; and Department of Neurology (M.M.P.S.), University of Utah, Salt Lake City. keegan.bmark@mayo.edu.
2From the Departments of Neurology (B.M.K., O.H.K., E.P.F.) and Neuroradiology (T.J.K., B.G.W.), Mayo Clinic, Rochester; Department of Neurology (W.F.S.), University of Minnesota, Minneapolis; and Department of Neurology (M.M.P.S.), University of Utah, Salt Lake City.
OBJECTIVE:
To report patients with progressive motor impairment resulting from an isolated CNS demyelinating lesion in cerebral, brainstem, or spinal cord white matter that we call progressive solitary sclerosis.
METHODS:
Thirty patients were identified with (1) progressive motor impairment for over 1 year with a single radiologically identified CNS demyelinating lesion along corticospinal tracts, (2) absence of other demyelinating CNS lesions, and (3) no history of relapses affecting other CNS pathways. Twenty-five were followed prospectively in our multiple sclerosis (MS) clinic and 5 were identified retrospectively from our progressive MS database. Patients were excluded if an alternative etiology for progressive motor impairment was found. Multiple brain and spinal cord MRI were reviewed by a neuroradiologist blinded to the clinical details.
RESULTS:
The patients' median age was 48.5 years (range 23-71) and 15 (50%) were women. The median follow-up from symptom onset was 100 months (range 15-343 months). All had insidiously progressive upper motor neuron weakness attributable to the solitary demyelinating lesion found on MRI. Clinical presentations were hemiparesis/monoparesis (n = 24), quadriparesis (n = 5), and paraparesis (n = 1). Solitary MRI lesions involved cervical spinal cord (n = 18), cervico-medullary/brainstem region (n = 6), thoracic spinal cord (n = 4), and subcortical white matter (n = 2). CSF abnormalities consistent with MS were found in 13 of 26 (50%). Demyelinating disease was confirmed pathologically in 2 (biopsy, 1; autopsy, 1).
CONCLUSIONS:
Progressive solitary sclerosis results from an isolated CNS demyelinating lesion. Future revisions to MS diagnostic criteria could incorporate this presentation of demyelinating disease.
The abstract can be seen
here.