Differential diagnoses of multiple sclerosis

Neuromyelitis optica (NMO, Devic’s syndrome) was long considered a subtype of multiple sclerosis (MS), but represents a disease pattern of its own. Common to both diseases is the demyelinating inflammation (demyelination of the nerve sheaths). In NMO, the spinal cord and optic nerve are particularly affected.

Typical is a long-distance inflammation of the spinal cord over three or more segments, which causes sensory disturbances and/or paralysis, as well as inflammation of the optic nerve with visual impairment and pain when moving the eyes. In many cases, either the spinal cord or the optic nerve is affected first alone. In the brain, inflammation foci can also be detected in about 50% of NMO patients, but these are clearly different from the inflammation foci of multiple sclerosis.

Just like MS, NMO is usually a relapsing-remitting disease, but the symptoms do not usually regress spontaneously or completely, as is often the case in MS. NMO is more severe than MS and patients are more dependent on external help. NMO can be distinguished from other inflammatory demyelinating diseases of the nervous system by positive aquaporin antibodies in the blood.A differentiation to MS is also possible, because in NMO oligoclonal bands are less frequently found in the liquor (spinal fluid) (in multiple sclerosis 95%, see Liquor diagnostics in multiple sclerosis). Acute disseminated encephalomyelitis (ADEM) is also an inflammatory disease of the central nervous system, which is accompanied by demyelination of the nerve sheaths.

In contrast to multiple sclerosis, ADEM mainly affects children and young adults and often occurs after an infection, especially of the upper respiratory tract. After a measles vaccination, ADEM occurs with a probability of 1 in 1 million; with a measles infection, the probability is three times as high, at 1 in 1,000. Unlike MS, ADEM does not occur in relapses, but mostly once.

A recurrent course is rare, 90% of patients fully recover from the disease. ADEM presents with nausea, vomiting, headache, meningismus (strong pain when moving the head to the chest), confusion and various neurological symptoms that may be very similar to MS. However, the accompanying symptoms mentioned are rare in MS. The distribution patterns of inflammatory lesions in MS and ADEM differ in the imaging of the head: ADEM occurs more in the area of the cerebral cortex and in deep brain nuclei, while MS tends to occur around the ventricular system. In addition to imaging, CSF puncture can help to differentiate: In MS the oligoclonal bands are almost always present, in ADEM they are much less frequent.