Crocodile tears syndrome after vestibular schwannoma surgery

Crocodile tears syndrome (CTS) is a lacrimal hypersecretion disorder characterized by excessive tearing with gustatory stimulation while eating, drinking, or smelling food. Surgeons tend to overlook CTS after vestibular schwannoma (VS) surgery because its symptoms are less obvious compared with facial paralysis. The authors aim to elucidate the precise incidence and the detailed natural course of CTS after VS surgery.

This study included 128 consecutive patients with unilateral VSs resected via a retrosigmoid, lateral suboccipital approach. Clinical information on the patients was obtained by retrospective chart review. The presence of, time of onset of, and recovery of patients from CTS were obtained from the chart or evaluated from the most recent outpatient visit.

A total of 14 patients (10.9%) developed CTS. Motor function of the facial nerve at discharge was statistically related to the occurrence of CTS (p < 0.001). The odds ratio of House-Brackmann Grade 4 compared with Grade 1 was 86.4 (p < 0.001). A bimodal distribution of CTS onset was observed, with a mean onset of 6.1 ± 4.0 months after resection. The CTS improved in 10 patients (71%) at various intervals, whereas CTS resolved in only 7 patients (50%) at a mean interval of 10.9 ± 7.9 months. The mean interval to recovery in the early-onset group was 9.7 ± 7.9 months, and it was 18 months in the late-onset group; the mean is given ± SD throughout.

The occurrence of CTS following VS surgery was more common than expected; however, a surgical procedure intended to protect the functioning of the facial nerve appears to be conducive to reduction of the occurrence of CTS. To reduce the distress caused by CTS, all patients should be given sufficient information and provide their informed consent prior to surgery.