Related Experiment Video
Updated: Jul 29, 2026

Rat Model of Widespread Cerebral Cortical Demyelination Induced by an Intracerebral Injection of Pro-Inflammatory Cytokines
Published on: September 21, 2021
Multiple sclerosis trait: the premorbid stage of multiple sclerosis. A hypothesis
1Department of Neurology, Harvard Medical School and Beth Israel Deaconess Medical Center, Boston, MA, USA. cposer@bidmc.harvard.edu
Abstract:
The unexpectedly low rate of concordance in monozygotic (MZ) twins with multiple sclerosis (MS) suggests that they share a systemic condition called the multiple sclerosis trait. This trait constitutes the premorbid stage of the disease and is quite distinct from asymptomatic MS. It results from the action of an antigenic challenge to the immune system of a genetically susceptible person but is short of producing lesions of the central nervous system parenchyma; in fact, the disease may never develop in people with the trait. An environmental triggering event is required to transform the trait into the disease. The discordance of clinical involvement and magnetic resonance images in MZ twins reflects differences in the effect of environmental influences.
Related Concept Videos
Biological Causes of Schizophrenia
Genetic Factors in Schizophrenia
The genetic basis of schizophrenia is strongly supported by family and twin studies.
Multiple Sclerosis l: Introduction
Alzheimer Disease l: Introduction
Parkinson Disease ll: Pathophysiology
Huntington Disease l: Introduction
Myasthenia Gravis ll: Pathophysiology

