The study of brain MRI findings in patients with optic neuritis proved by VEP

Subject Areas : علوم پزشکی

Saeed Naghibi ¹ , Gholam reza Malek zadeh ² , Taraneh Honarparvar ³

1 - استادیار، دانشکده پزشکی، دانشگاه آزاد اسلامی مشهد، مشهد، ایران
2 - استادیار، دانشکده پزشکی، دانشگاه آزاد اسلامی مشهد، مشهد، ایران
3 - دانشجوی پزشکی، دانشکده پزشکی، دانشگاه آزاد اسلامی مشهد، مشهد، ایران

Received: 2017-06-05 Accepted : 2017-06-05 Published : 2017-05-22

Keywords: MRI, VEP, optic neuritis,

Abstract :

Introduction: Acute optic neuritis is the most commmon optic neuropathy in adults and adolescents aged 18 to 35, with an annual incidence of approximately 5 per 100 thousand cases, and the prevalence (pre accelerometers) reported that 115 of the 100 thousand and is more common in female. The evaluation included MRI, VEP, and CSF examination is over. The most common form of MS is optic neuritis so the timely and accurate identification of early diagnosis to prevent irreversible complications and the risk of developing MS and definitive MS is required.   Methods and Materials: This study included 22 patients who presented with complaints of visual impairment and the diagnosis of optic neuritis is done. VEP and MRI was performed add to the assessments of the patient information. Findings add to the SPSS software, version 21, and the datas were processed with McNemar's test and U Mann-Whitney test and the results were recorded.   Results:The patients had a mean age of 29.5 years and inclusaded 16 women and 6 men. The most common clinical symptom is blurred vision (respectively 76/3%). Involement of the right eye is more than the left eye (72/7%). The minimum range of P100 wave in normal VEP was 94 and the maximum range was 100 and in the abnormal VEP the minimum range was 114 and the maximum range was 148. MRI contrast uptake in the population was 59/4% on the left side and 72/7% on the right side. The most common side was bilateral involvement and then right side and finally left side. Most commonly involved segment of the optic nerve on both sides was intra orbital and then involvement of all the three segments in the optic nerve. The degree of parenchymal involvement of the population was respectively 77/3%. The most common parenchymal lesions areas on MRI were, supratentorial and inferatentorial or jast supratentorial. The mean length of the involved segment nerve at the left side was 8.79 mm and at the right side was 11.42 mm, and the mean diameter of the involved nerve was 3.90 mm on the left side and 4.06 mm on the right side. VEP and MRI diagnosis of optic neuritis with the two methods are not significantly different (p = 0/75) and also there was no significant differences between the mean diameter of the optic nerve in both groups with normal and abnormal VEP was observed (p=0/41).   Conclusions: The diagnostic accuracy of MRI compared to the VEP test is high, so that the sensitivity and specificity for the left eye was respectively 100% and 77/78%, and respectively for the right eye was 93/75% and 83/33%. As a result, if VEP was impaired, it was needed to be confirmed by MRI. Because it can be have approximately 22.22% false positive results.    

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