Incidence, Clinician Misdiagnosis Rate, Radiologist Missed Diagnosis Rate, and Lesion Distribution of Isolated Medial Longitudinal Fasciculus Infarction: A Retrospective Study.

PURPOSE: This study aimed to determine the incidence, clinician misdiagnosis rate, radiologist missed-diagnosis rate, and lesion distribution of isolated medial longitudinal fasciculus infarction (IMLFI).

PATIENTS AND

METHODS

A retrospective analysis was conducted on 14,385 patients hospitalized with ischemic stroke at the General Hospital of Ningxia Medical University between 2020 and 2023. The objectives were to estimate the incidence of IMLFI, assess clinician misdiagnosis and radiologist missed-diagnosis rates based on initial clinical and imaging reports, and characterize the anatomical distribution of lesions.

RESULTS

IMLFI accounted for 0.17% (24/14,385) of all ischemic stroke cases. Among these patients, 70.83% (17/24) were male, with a mean age of 60.88 ± 10.25 years. Nineteen patients presented with internuclear ophthalmoplegia (INO). Most cases (75.00%, 18/24) were initially evaluated in the Emergency Department by neurologists, while the remaining 25.00% (6/24) were first assessed in the Department of Ophthalmology. The overall initial clinical misdiagnosis rate was 41.67% (10/24), with the most frequent misdiagnoses being oculomotor nerve palsy (50.00%) and peripheral vertigo (40.00%). On initial radiological evaluation, diffusion-weighted imaging (DWI) lesions were missed in 37.50% (9/24) of cases. Anatomically, lesions were distributed in the caudal midbrain (20.83%, 5/24), the midbrain-pontine junction (4.17%, 1/24), and the rostral pons (45.83%, 11/24).

CONCLUSION

IMLFI is a rare clinical entity with a high risk of both clinical misdiagnosis and radiological oversight. Lesions are predominantly located from the caudal midbrain to the rostral pons, highlighting the need for increased clinical and radiological awareness of this condition.