A new subtype of multiple sclerosis (MS) has been identified, ushering in new potential for more specific diagnoses and even personalised medicine approaches.
According to research from the Cleveland Clinic in Ohio, USA, the newly discovered MS subtype – termed myelocortical MS (MCMS) – is characterised by neuronal cell death, but without cerebral white matter demyelination, the traditional hallmark of the disease.
Specifically, the research was conducted on 100 MS donor brains, using both MRI and post-mortem examination. While MRI revealed no apparent difference between the samples, post-mortem examinations showed that lesions supposedly attributable to myelin loss were actually caused by neuronal swelling in 12 out of the 100 cases.
These 12 brains showed no sign of cerebral white matter demyelination, but were still associated with demyelination of the spinal cord and cerebral cortex, in addition to greater cortical neuron loss compared to healthy controls. Therefore, while still clearly MS cases, they did not fit the usual profile, and thus the MCMS nomenclature was born.
Crucially, the discovery sheds new light on the process of neuronal degeneration in MS, suggesting that there is more than just demyelination at play. Going forward, the researchers note the importance of further exploring the mechanisms of primary neuronal degeneration and axonal pathology, as well as placing greater emphasis on more sensitive diagnostic methods and combination therapies that can detect the disease at an earlier stage.