[Arnold-Chiari I malformation: three unusual manifestations]

Arnold-Chiari Syndrome I is a malformation of the cervicomedullary junction, manifesting usually with downbeat nystagmus, palsy of the caudal cerebral nerves, headache, and vertigo.

We present three patients with unusual symptomatology.

A two-year-old child with isolated non-ocular torticollis, a 52-year-old male patient, and a 42-year-old female patient, both with gaze-evoked nystagmus, underwent a cerebral MRI examination. The findings of the first two patients were typical for an Arnold-Chiari syndrome. The malformation in the third patient was found only by reviewing the initial MRI.

Arnold-Chiari malformation may manifest atypically. An important step in the work-up of these patients is to ask the neuroradiologist to include the cervicomedullary junction in his evaluation.