I have read some medical journals that describe the ependymal for dash sign as an early marker for MS. It seems that most of these papers were written over a decade ago it makes me wonder if they are still considered as a relevant finding. My MRI images show them but they were not reported on. Granted, my MRI was interpreted by a general radiologist and not a neuroradiologist so I wouldn't expect it to be picked up on easily. Do you find that the dot dash sign has clinical relevance when reviewing MRI's in the early stages of MS?
I view the “dot dash sign” as a potential indicator of early MS. The involvement of the corpus callosum is not specific for MS but can be seen in other injuries to the nervous system as well (i.e., Susac’s Disease, Marchiafava-Bignami, leukodystrophies, neoplasm and lymphoma, vascular injuries such as stroke, etc). Articles commenting on the dot-dash sign and development of MS tend to show evolution of these initial lesions into the classic “dawson’s finger” that is characteristic of periventricular lesions of MS. The presence of the dot-dash sign in the absence of the cardinal lesion morphology of MS (i.e., periventricular/juxtacortical/infratentorial lesions) should be monitored but not regarded as part of the rationale or proof for treatment of supposed MS.
A. Scott Nielsen MD MMSc
Neurologist and MS Specialist at Kaiser Permanente