Causes and Outcomes of Misdiagnosed Optic Nerve Sheath Meningioma
Published online Dec. 17, 2018
Kahraman-Koytak et al. documented the reasons for initial misdiagnosis of optic nerve sheath meningioma (ONSM). They found that misdiagnosis occurs often, with optic neuritis being the most common erroneous label. Factors contributing to misdiagnosis were inaccurate funduscopic exams, biased pre-established diagnoses, failure to order correct tests, and incorrect interpretation of magnetic resonance imaging (MRI) results.
For this retrospective study, the authors reviewed records of 35 patients (mean age, 45 years) with unilateral ONSM who were seen at Emory University’s neuro-ophthalmology practice during a 15-year period. To ascertain causes of diagnostic errors, the Diagnosis Error Evaluation and Research taxonomy tool was applied to cases of missed or delayed diagnosis.
Of the 35 patients, 25 (71%) had a delayed or initially missed diagnosis, the mean of which was 63 months. The most common diagnostic error (n = 19) was clinician assessment failure (errors in hypothesis generation and weighing), followed by errors in diagnostic testing (n = 15). The most common initial misdiagnosis was optic neuritis (n = 12). Another common contributor to diagnostic delay or inaccuracy was failure to recognize optic neuropathy in patients with ocular disorders. Sixteen (64%) of the 25 patients had poor visual outcomes.
Of the 16 patients with a missed diagnosis, five had unnecessary lumbar puncture, 12 received inappropriate lab tests, and six had unwarranted steroid treatment. Eleven of the 16 had previous MRI results that were considered healthy: Five showed ONSM but were misread by a clinician other than a neuroradiologist, and six were performed improperly (without orbital sequence or contrast).
Compressive optic neuropathy should be considered in the differential diagnosis of monocular vision loss that is painless and progressive. Diagnostic delays and errors are costly and often lead to suboptimal visual outcomes in patients with ONSM.
The authors emphasized that various efforts can minimize diagnostic difficulty, including effective neuroimaging education, better diagnostic strategies, and easier access to neuro-ophthalmologists.
The original article can be found here.