Isolated Trochlear Nerve Palsy in a Patient with Superior Cerebellar Rete Mirabile

Rete mirabile is a very rare vascular malformation and superior cerebellar artery (SCA) rete mirabile is not reported previously. We report a new case of rete mirabile of SCA initially detected by magnetic resonance imaging and transfemoral cerebral angiography. This report illustrates the case of a 58-year-old man who presented with vertical diplopia. Brain magnetic resonance angiography and transfemoral cerebral angiography revealed a rete mirabile of SCA and 3-dimensional volume isotropic turbo spin echo acquisition, brain magnetic resonance imaging sequence, demonstrated that the cisternal segment of the ipsilateral trochlear nerve was compressed by this vascular malformation. We assumed that his cranial nerve palsy was caused by the rete mirabile of the right SCA. During the 8 weeks presence of diplopia, the patient was observed and the symptom was relieved spontaneously. We provide a first report in the literature of rete mirabile involving the SCA and suggest a descriptive knowledge of rete mirabile for clinicians during decision-making of treatment.