Tumefactive multiple sclerosis

rdf:langString Tumefactive multiple sclerosis

rdf:langString An example of a ring-enhancement around a lesion in gliobastoma. In tumefactive multiple sclerosis, the ring-enhancement is open, not forming a complete ring.

rdf:langString Tumefactive multiple sclerosis is a condition in which the central nervous system of a person has multiple demyelinating lesions with atypical characteristics for those of standard multiple sclerosis (MS). It is called tumefactive as the lesions are "tumor-like" and they mimic tumors clinically, radiologically and sometimes pathologically. These atypical lesion characteristics include a large intracranial lesion of size greater than 2.0 cm with a mass effect, edema and an open ring enhancement. A mass effect is the effect of a mass on its surroundings, for example, exerting pressure on the surrounding brain matter. Edema is the build-up of fluid within the brain tissue. Usually, the ring enhancement is directed toward the cortical surface. The tumefactive lesion may mimic a malignant glioma or cerebral abscess causing complications during the diagnosis of tumefactive MS. T2-hypointense rim and incomplete ring enhancement of the lesions on post-gadolinium T1- weighted imaging on brain MRI enable accurate diagnosis of TDL Normally a tumefactive demyelinating lesion appears together with smaller disseminated lesions separated in time and space, yielding a diagnosis of Multiple Sclerosis. Hence the name "tumefactive multiple sclerosis". When the demyelinating lesion appears alone it has been termed solitary sclerosis. These cases belong to a multiple sclerosis borderline and there is currently no universal agreement on how they should be considered. Tumefactive multiple sclerosis is a demyelinating and inflammatory disease. Myelination of the axons are highly important for signalling as this improves the speed of conduction of action potentials from one axon to the next. This is done through the formation of high-resistance, low-conductance myelin sheaths around the axons by specific cells called oligodendrocytes. As such, the demyelination process affects the communication between neurons and this consequently affects the neural pathways they control. Depending on where the demyelination takes place and its severity, patients with tumefactive MS have different clinical symptoms.