Diffusion-weighted imaging as an aid in the diagnosis of the etiology of medial longitudinal fasciculus syndrome

Purpose: Internuclear ophthalmoplegia is caused by a lesion; stroke, multiple sclerosis, brain metastases, or trauma may produce lesions of the medial longitudinal fasciculus (MLF). Imaging techniques, such as DWI, can help identify the site of the lesion in order to speed diagnosis and lead to appropriate treatment. Methods: Over an 8-month period, eight consecutive patients with suspected MLF syndrome (most secondary to ischemic stroke) underwent MRI examinations, including DWI sequencing, at an academic center in Taiwan. Results: In all eight patients, abnormal high-signal lesions were found close to the floor of the fourth ventricle on the dorsal side of the pons. A neuroanatomical comparison showed that the location of the lesions was identical to the anatomical position of the MLF. Conclusion: Using DWI, good clinico-radiological correlation was found in all eight ischemic stroke patients diagnosed with MLF syndrome. DWI may broaden the application of MRI in the diagnosis of MLF syndrome.