From the Guidelines
VEP abnormalities are present in a significant proportion of patients with multiple sclerosis (MS), although the exact rate is not specified in the most recent and highest quality study available, which is from 2001 1. The presence of VEP abnormalities in MS patients can be attributed to demyelination in the optic pathways, which may be detected even in patients without a history of optic neuritis.
- Key points to consider when interpreting VEP results in MS diagnosis include:
- The importance of correct interpretation of VEP results, as emphasized in the guidelines from the international panel on the diagnosis of MS 1.
- The potential for VEP to provide objective evidence of a second lesion, supplementing information from clinical examination, particularly when the only clinically expressed lesion did not affect the visual pathways 1.
- The role of VEP in detecting subclinical lesions in the visual pathway, which may not be apparent on clinical examination or reported by the patient. Given the information available from the study 1, it is essential to consider the diagnostic criteria for MS and the value of VEP in providing supportive evidence for diagnosis.
- The study highlights the need for careful interpretation of VEP results, along with other diagnostic tools like MRI and CSF analysis, to ensure accurate diagnosis and appropriate management of MS. The use of VEP as a diagnostic tool in MS should be guided by the most recent clinical guidelines and expert recommendations, taking into account the individual patient's clinical presentation and disease course.
From the Research
VEP Abnormalities in MS
- The rate of VEP abnormalities in MS patients varies across studies, with some reporting abnormal VEPs in 100% of patients with definite MS 2.
- In patients with probable or possible MS, abnormal VEPs were found in 70% of cases 2.
- A study using equiluminant red-green and blue-yellow VEPs found abnormal latencies in 53.3% to 58.3% of MS patients for red-green VEPs and 56.6% to 48.3% for blue-yellow VEPs 3.
- Another study found that VEP assessment was helpful in diagnosing childhood and juvenile MS, with abnormal VEPs typical of MS observed in 100% of MS patients with optic neuritis and changes in VEP indicating clinically silent lesions in 86% of patients with clinically definite MS 4.
Comparison with Other Diagnostic Tools
- The combination of VEP and brain stem auditory evoked potential (BAEP) recordings increased the diagnostic yield to 100% in patients with definite MS and 80% in patients with probable or possible MS 2.
- A study comparing multimodal evoked potentials (MMEPs) with MRI found that MMEPs added information to MRI in identifying patients with higher risk of relapse or development of disability after a clinically isolated syndrome (CIS) only when all three EPs were abnormal 5.
- The presence of three abnormal EPs increased the risk of reaching moderate disability independently of baseline MRI findings 5.