Appearance of cerebellar cyst following microvascular decompression to treat hemifacial spasm: a report of two cases and literature review.

Microvascular decompression (MVD) is an effective and safe approach for treating hemifacial spasm (HFS). Postoperative complications may include facial nerve palsy, hearing loss, intracerebral haematoma, and brainstem infarction. The occurrence of intracranial cyst following MVD is extremely rare, with few cases documented in the literature. Herein, the cases of two patients with HFS who developed ipsilateral cerebellar cyst following MVD are reported. The first patient was a 50-year-old male presenting with a 6-year history of HFS on the right side of his face. MVD was performed, and 12 days postoperatively he developed dizziness and nausea. Magnetic resonance imaging (MRI) showed a cyst in the ipsilateral cerebellum. Antibiotic treatment provided no benefit, and the cyst was drained. The second patient was a 44-year-old female presenting with a 4-year history of HFS on the right side of her face. MVD was performed, and 18 days following surgery, she developed dizziness and nausea. MRI showed an ipsilateral cerebellar cyst. Conservative treatment was applied and the cyst shrunk. At the 2-month follow-up appointment, symptoms were completely resolved in both patients. Cerebellar cyst is a rare complication following MVD. Timely diagnosis and appropriate treatment should be emphasized, and surgical treatment may be unnecessary.