Diplopia following microvascular decompression surgeries: illustrative cases

BACKGROUND Microvascular decompression is an effective treatment strategy for trigeminal neuralgia. However, there may be inadvertent complications involving adjacent cranial nerves during or months after the operation. This case lesson highlights the potential manifestations, both optical and nonneurologic (monocular) and binocular diplopia, after microvascular decompression in two patients. Neurosurgeons should recognize monocular versus binocular causes of diplopia after neurosurgical microvascular decompression. OBSERVATIONS The authors reported on two patients who presented with diplopia after microvascular decompression for trigeminal neuralgia. The first patient had binocular diplopia with a paradoxical head tilt potentially due to a contiguous trochlear nerve palsy. The second patient had monocular diplopia due to dry eye syndrome from trigeminal nerve dysfunction. However, within 2 years after their operations, both patients had resolution of their diplopia without additional surgical intervention. LESSONS Both monocular and binocular diplopia can be presenting symptoms of cranial neuropathies after microvascular decompression for trigeminal neuralgia. Most cases of postoperative diplopia (both monocular and binocular) resolve spontaneously over time without additional neurosurgical treatment.