Radiologically isolated syndrome (RIS) is a clinical situation in which a person has white matter lesions suggestive of multiple sclerosis (MS), as shown on an MRI scan that was done for reasons unrelated to MS symptoms. The nerve lesions in these people show dissemination in space with an otherwise normal neurological examination and without historical accounts of typical MS symptoms. [1]
MRI findings that are consistent with multiple sclerosis have been observed in healthy people who underwent MRI scanning, and 50% go on to develop symptomatic MS, sometimes with a primary progressive course. [2] [3] This condition was first characterized in 2009. [4]
The criteria for an RIS diagnosis are as follows: [5] [4] [6]
RIS is discovered when an MRI scan is performed for other reasons. The most common symptom that led to the incidental discovery of RIS is headache. [5] Other common reasons are trauma, psychiatric disorders, and endocrinological disorders. [5]
Currently, routine clinical follow-up and MRI neuroimaging surveillance is the standard by which patients are observed. [4] While treatment of MS disease modifying therapies have been given to some individuals with RIS, the majority opt for active surveillance and the appearance of clinical symptoms before commencing treatment, [5] as treatment is considered controversial. [8]
In a 5 year study, clinical events, which refers to the first symptoms of exacerbations, clinical attacks, flare ups, or severe symptoms, indicative of MS, appeared in 34% of individuals. [9] Of those who developed symptoms, 9.6% fulfilled criteria for primary progressive multiple sclerosis (PPMS). [9]
Due to the incidental nature of RIS, exact figures on prevalence is unknown, though it has been suggested that RIS is the most common type of asymptomatic MS. [10] The prevalence may be higher in relatives of patients with MS. [11] One study, at a university hospital that is located in a high region of MS disease incidence, put the disease prevalence at approximately 1 in 2000. [12] An earlier study in 1961 of 15,644 autopsies found 12 cases (0.08%) of unexpected MS findings without a previous history of MS symptoms. [5] [13] The mean age of first indication of RIS from 451 patients is 37.2 years. [9]
Though rare, some children that have had MRI scans for reasons unrelated to MS have shown signs of RIS. The most common reason for an initial MRI in these children was a headache. The first occurrence of a clinical event characteristic of MS in nearly half of the children examined was 2 years, though in a majority of cases, 'radiologic evolution', i.e. the increase in the number of size of lesions as detected in subsequent MRI, developed after one year. The presence of oligoclonal bands in the CSF and spinal cord lesions were associated with an increased risk of a first clinical event characteristic of MS. It was found that children with RIS had a substantial risk of subsequent clinical symptoms and/or radiologic evolution. [6]
Calls have been made for longer prospective studies, tracking the development of potential disease progression over a longer period of time are warranted. This would ensure criteria in RIS is satisfactory and whether consideration should be given to treating individuals with RIS on current MS medication. [5] [7]
RIS has been linked to prodromal multiple sclerosis. [14]
The acronym RIS was coined in 2009 by Okuda and colleagues. [4] Siva and colleagues suggested an alternate name, radiologically uncovered asymptomatic possible inflammatory-demyelinating disease (RAPIDD). [5] [15]
Acute disseminated encephalomyelitis (ADEM), or acute demyelinating encephalomyelitis, is a rare autoimmune disease marked by a sudden, widespread attack of inflammation in the brain and spinal cord. As well as causing the brain and spinal cord to become inflamed, ADEM also attacks the nerves of the central nervous system and damages their myelin insulation, which, as a result, destroys the white matter. It is often triggered by a viral infection or vaccinations.
Optic neuritis describes any condition that causes inflammation of the optic nerve; it may be associated with demyelinating diseases, or infectious or inflammatory processes. It is also known as optic papillitis, neuroretinitis when there is a combined involvement of optic disc and surrounding retina in the macular area and retrobulbar neuritis. It is most often associated with multiple sclerosis, and it may lead to complete or partial loss of vision in one or both eyes. Other causes include:
Multiple sclerosis (MS), also known as encephalomyelitis disseminata, is the most common demyelinating disease, in which the insulating covers of nerve cells in the brain and spinal cord are damaged. This damage disrupts the ability of parts of the nervous system to transmit signals, resulting in a range of signs and symptoms, including physical, mental, and sometimes psychiatric problems. Specific symptoms can include double vision, blindness in one eye, muscle weakness, and trouble with sensation or coordination. MS takes several forms, with new symptoms either occurring in isolated attacks or building up over time. Between attacks, symptoms may disappear completely, although permanent neurological problems often remain, especially as the disease advances.
Interferon beta-1a is a cytokine in the interferon family used to treat multiple sclerosis (MS). It is produced by mammalian cells, while interferon beta-1b is produced in modified E. coli. Some research indicates that interferon injections may result in an 18–38% reduction in the rate of MS relapses.
In medicine, any disease is classified asymptomatic if a patient tests as carrier for a disease or infection but experiences no symptoms. Whenever a medical condition fails to show noticeable symptoms after a diagnosis it might be considered asymptomatic.
Interferon beta-1b is a cytokine in the interferon family used to treat the relapsing-remitting and secondary-progressive forms of multiple sclerosis (MS). It is approved for use after the first MS event. Closely related is interferon beta 1a, also indicated for MS, with a very similar drug profile.
The McDonald criteria are diagnostic criteria for multiple sclerosis (MS). These criteria are named after neurologist W. Ian McDonald who directed an international panel in association with the National Multiple Sclerosis Society (NMSS) of America and recommended revised diagnostic criteria for MS in April 2001. These new criteria intended to replace the Poser criteria and the older Schumacher criteria. They have undergone revisions in 2005, 2010 and 2017.
Angiomyolipomas are the most common benign tumour of the kidney. Although regarded as benign, angiomyolipomas may grow such that kidney function is impaired or the blood vessels may dilate and burst, leading to bleeding.
Intention tremor is a dyskinetic disorder characterized by a broad, coarse, and low frequency tremor evident during deliberate and visually-guided movement. An intention tremor is usually perpendicular to the direction of movement. When experiencing an intention tremor, one often overshoots or undershoots one's target, a condition known as dysmetria. Intention tremor is the result of dysfunction of the cerebellum, particularly on the same side as the tremor in the lateral zone, which controls visually guided movements. Depending on the location of cerebellar damage, these tremors can be either unilateral or bilateral.
Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease that affects the central nervous system (CNS). Several therapies for it exist, although there is no known cure.
Inflammatory demyelinating diseases (IDDs), sometimes called Idiopathic (IIDDs) because the unknown etiology of some of them, and sometimes known as borderline forms of multiple sclerosis, is a collection of multiple sclerosis variants, sometimes considered different diseases, but considered by others to form a spectrum differing only in terms of chronicity, severity, and clinical course.
Baló's concentric sclerosis is a disease in which the white matter of the brain appears damaged in concentric layers, leaving the axis cylinder intact. It was described by József Mátyás Baló who initially named it "leuko-encephalitis periaxialis concentrica" from the previous definition, and it is currently considered one of the borderline forms of multiple sclerosis.
Multiple sclerosis can cause a variety of symptoms: changes in sensation (hypoesthesia), muscle weakness, abnormal muscle spasms, or difficulty moving; difficulties with coordination and balance; problems in speech (dysarthria) or swallowing (dysphagia), visual problems, fatigue and acute or chronic pain syndromes, bladder and bowel difficulties, cognitive impairment, or emotional symptomatology. The main clinical measure in progression of the disability and severity of the symptoms is the Expanded Disability Status Scale or EDSS.
Research in multiple sclerosis may find new pathways to interact with the disease, improve function, curtail attacks, or limit the progression of the underlying disease. Many treatments already in clinical trials involve drugs that are used in other diseases or medications that have not been designed specifically for multiple sclerosis. There are also trials involving the combination of drugs that are already in use for multiple sclerosis. Finally, there are also many basic investigations that try to understand better the disease and in the future may help to find new treatments.
A clinically isolated syndrome (CIS) is a clinical situation of an individual's first neurological episode, caused by inflammation or demyelination of nerve tissue. An episode may be monofocal, in which symptoms present at a single site in the central nervous system, or multifocal, in which multiple sites exhibit symptoms. CIS with enough paraclinical evidence can be considered as a clinical stage of multiple sclerosis (MS). It can also be retrospectively diagnosed as a kind of MS when more evidence is available.
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.
Current standard for diagnosing multiple sclerosis (MS) is based in the 2018 revision of McDonald criteria. They rely in MRI detection of demyelinating lesions in the CNS, which are distributed in space (DIS) and in time (DIT). It is also a requirement that any possible known disease that produces demyelinating lesions is ruled out before applying McDonald's criteria.
Multiple sclerosis (MS) can be pathologically defined as the presence of distributed glial scars (scleroses) in the central nervous system that must show dissemination in time (DIT) and in space (DIS) to be considered MS lesions.
MOG antibody disease, MOGAD or Anti-MOG associated encephalomyelitis is an inflammatory demyelinating disease of the central nervous system. Serum anti-myelin oligodendrocyte glycoprotein antibodies are present in up to half of patients with an acquired demyelinating syndrome and have been described in association with a range of phenotypic presentations, including acute disseminated encephalomyelitis, optic neuritis, transverse myelitis, and neuromyelitis optica.
Several biomarkers for diagnosis of multiple sclerosis, disease evolution and response to medication are under research. While most of them are still under research, there are some of them already well stablished: