BACKGROUND: 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.
PATIENTS AND METHODS: We present three patients with unusual symptomatology.
RESULTS: 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.
CONCLUSIONS: 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.