The course of disease in more than >80% of patients with multiple sclerosis is relapsing remitting.in natural course of disease after 10-15 years, about sixty percent of patients experience a gradual decline in their neurological examination (secondar progressive MS, SPMS). In about 15% of patients have progressive disease from onset (primary progressive MS, PPMS).
In recent decades, many drugs are introduced for treatment MS. The primary aim of these drugs is to control relapse and progression in patients with MS. So, it is essential to design instrument for assessment the neurological function in these patients and evaluate the efficacy of the specific drugs.
Unfortunately, in many centers, the progress of the disease is detected with a delay and the golden time for treatment escalating is lost. One of the causes of this situation is the lack of familiarity of clinicians with tools for progression investigation.
Different type of scales has been designed to evaluate and measure neurological function in these patients. The described impairment in different parts of neurological system such as motor, sensory, cerebellar, autonomic and visual systems. Also, these tools have been used in different clinical trials.
The most popular and widely used instrument is the Expanded Disability Status Scale (EDSS) of Kurtzke. The EDSS is a physician-administered assessment scale investigating the functional systems of the central nervous system. This instrument is used to find progression and neurological deterioration in patients with MS. It consists of ordinal rating system ranging from 0 (normal neurological status) to 10 (death due to MS) in 0.5 increments interval (when reaching EDSS 1). The lower scale values of the EDSS measure impairments based on the neurological examination, while the upper range of the scale (> EDSS 6) measures handicaps of patients with MS. The determination of EDSS 4 – 6 is heavily dependent on aspects of walking ability.