Chiari I has protean clinical manifestations (1). Tics in patients with Chiari I malformation is very rare; in these cases, it is thought that the Chiari I malformation and the tic are unrelated. However, Berthet et al. have described a case where the tic resolved soon after the patient had foramen magnum decompression for Chiari malformation.
The case that Berthet et al. described was a 7-year old boy who had presented to them with tics. The tics manifested as stereotyped movements of head and chest bending forwards and to the left. This abnormal movement was associated with a grimace. During these episodes, the patient felt a sensation of breath locking. The patient was symptomatic for two years. On MRI of the head, the patient was noted to have Chiari I.5 malformation, small posterior fossa and concurrent syringomyelia (D4-D5). No other abnormality was found to account for tics. The patient remained symptomatic from tics for 2-years patient was offered foramen magnum decompression and duraplasty. Following the surgery, the patient’s tic disappeared in the first postoperative week. There was no relapse at the 2-year post-op follow-up.