Video 1—Friedreich’s Ataxia: A patient with Friedreich’s ataxia, a gait disorder due to both cerebellar and proprioceptive ataxia, has imbalance, staggers, and has difficulties in making a half-turn. Because of difficulties with tandem walking, the patient requires the intermittent support of a wall. The patient has dysmetria during nose–finger and finger chase tests, and instability in a standing position with the feet together because of cerebellar ataxia. There is an obvious loss of balance when the patient’s eyes are closed because of the proprioceptive component of the ataxia. Saccadic ocular pursuit and square-wave jerks due to fixation instability are shown, as well as diffuse abolition of the reflexes and right extensor plantar reflex.
Video 2—Ataxia with Oculomotor Apraxia Type 1: Choreic movement of the hands and trunk with cervical dystonia in a patient with ataxia with oculomotor apraxia type 1.
Video 3—Ataxia Telangiectasia: Right horizontal gaze-evoked nystagmus and nasal as well as temporal telangiectasias in a patient with ataxia telangiectasia.
Video 4—Oculomotor Apraxia Type 1: Oculocephalic dissociation in a patient with ataxia with oculomotor apraxia type 1. During the rotation of the head, a dissociation is expressed as a delay between the movement of the eyes following that of the head.