<unk>  is a condition in which the central nervous system of a person has<unk>  demyelinating lesions with atypical characteristics for those of standard<unk><unk>  (MS). It is called<unk>  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<unk>  lesion may mimic a malignant glioma or cerebral abscess causing complications during the diagnosis of<unk>  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<unk>  demyelinating lesion appears together with smaller disseminated lesions separated in time and space, yielding a diagnosis of<unk><unk> . Hence the name<unk> ". When the demyelinating lesion appears alone it has been termed solitary<unk> . These cases belong to a<unk><unk>  borderline and there is currently no universal agreement on how they should be considered.<unk>  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<unk>  MS have different clinical symptoms.
Tumefactive multiple sclerosis
CMV polyradiculomyelopathy
Paraneoplastic cerebellar degeneration
Post viral cerebellar ataxia
Juvenile primary lateral sclerosis
Malignant multiple sclerosis
Viliuisk encephalomyelitis
Chronic inflammatory demyelinating polyneuropathy