The Heimann-Bielschowsky phenomenon in vision loss

Although monocular nystagmus and oscillations are rare, patients presenting with monocular oscillopsia should be evaluated for superior oblique myokymia, acquired pendular nystagmus due to multiple sclerosis or oculopalatal tremor, iridodonesis and pseudophacodonesis. Patients with monocular or significantly asymmetric vision loss may develop monocular vertical pendular nystagmus known as the Heimann-Bielschowsky phenomenon (HBP). This is often due to an ocular condition such as unilateral cataract, and treatment of the condition (e.g., cataract extraction with normalization of vision) can resolve the HBP. Patients with HBP do not tend to experience oscillopsia since the etiology of the This patient had asymmetric retinitis pigmentosa (RP) with more peripheral visual field loss in the right eye, and presented with slow, large amplitude vertical oscillations of the right eye without oscillopsia. Although the oscillations were slower and larger than what is typically expected, it was thought that HBP related to his asymmetric RP provided the best explanation for these movements rather than a dissociated vertical deviation (which would not typically cross the midline) or a neurologic etiology (MRI demonstrated a normal posterior fossa, and there was no palatal tremor).