All About Multiple Sclerosis

More MS news articles for July 2003

Risk of Multiple Sclerosis in Acute Optic Neuritis Greater in Patients with Single Brain Lesion

By Elda Hauschildt
Doctor's Guide

A DGReview of :"High- and Low-Risk Profiles for the Development of Multiple Sclerosis Within 10 Years After Optic Neuritis: Experience of the Optic Neuritis Treatment Trial"
Archives of Ophthalmology

Patients with acute optic neuritis have a significantly higher risk of developing multiple sclerosis (MS) if they have a single brain lesion, indicates research by the United States Optic Neuritis Study Group.

However, higher numbers of lesions do not appreciably increase that risk, write researchers led by Dr. Roy W. Beck, from Jaeb Centre for Health Research, in Tampa, Florida.

They found approximately 40% of patients developed MS within 10 years of acute optic neuritis diagnosis. Most developed MS within the first 5 years, although some continued to develop MS in each year of follow-up. The 10-year risk of MS was 38%, and the 5-year risk was 30%.

"Our results have applicability not only to optic neuritis but also to patients seen with an initial demyelinating event of the brainstem or spinal cord, because the three presentations share a common pathogenesis and have been reported to have similar risks for MS," they state.

The researchers also write that the results reaffirm the prognostic value of an magnetic resonance imaging (MRI) scan at an initial episode of acute optic neuritis because a single brain MRI white matter lesion of at least 3-mm diameter markedly increased the risk of patients developing MS.

The results highlight the importance of an ophthalmologic examination for patients whose MRI of the brain is normal because ophthalmoscopy can identify features -- severe optic disc swelling, haemorrhages and exudates -- associated with a very low risk of developing MS.

"This natural history information is a critical input for estimating a patient's 10-year MS risk and for weighing the benefit of initiating prophylactic treatment at the time of acute optic neuritis or other initial demyelinating events in the central nervous system."

A total of 388 participants aged from 18 to 46 years and treated at 15 US clinical centres were enrolled. All experienced acute optic neuritis between July 1988 and June 1991 but did not have clinically definite MS.

Standardised neurological examinations were done at enrolment, after 6 and 12 months, and then annually until 1997. Willing participants underwent another standardised neurological assessment between 2001 and 2002.

Results indicate the 160 patients who had one or more typical lesions on baseline MRI had a 56% risk of developing MS. The 191 patients with no lesions at baseline had a 22% risk.

Among those with no lesions at baseline, male gender and optic disc swelling were associated with lower MS risk. Also associated with lower risk were three atypical features of optic neuritis: no light perception vision, absence of pain and ophthalmoscopic findings of severe optic disc oedema, peri-papillary haemorrhages or retinal exudates.

Arch Ophthalmol 2003 Jul;121:7:944-949. "High- and Low-Risk Profiles for the Development of Multiple Sclerosis Within 10 Years After Optic Neuritis: Experience of the Optic Neuritis Treatment Trial"

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