Eye movement disorders in inborn errors of metabolism: A quantitative analysis of 37 patients

Abstract

Inborn errors of metabolism are genetic disorders that need to be recognized as early as possible because treatment may be available. In late-onset forms, core symptoms are movement disorders, psychiatric symptoms, and cognitive impairment. Eye movement disorders are considered to be frequent too, although specific knowledge is lacking. We describe and analyze eye movements in patients with an inborn error of metabolism, and see whether they can serve as an additional clue in the diagnosis of particularly late-onset inborn errors of metabolism. Demographics, disease characteristics, and treatment data were collected. All patients underwent a standardized videotaped neurological examination and a video-oculography. Videos are included. We included 37 patients with 15 different inborn errors of metabolism, including 18 patients with a late-onset form. With the exception of vertical supranuclear gaze palsy in Niemann-Pick type C and external ophthalmolplegia in Kearns-Sayre syndrome, no relation was found between the type of eye movement disorder and the underlying metabolic disorder. Movement disorders were present Eye movement disorders in inborn errors of metabolism are very heterogeneous, even in patients with the same disorder, with the exception of a vertical supranuclear gaze palsy in Niemann-Pick type C and a progressive external ophthalmoplegia in Kearns-Sayre syndrome.Click here to access the podcast for this paper.

Inborn Errors of Metabolism with Ataxia: Current and Future Treatment Options

“…Some patients present with retinitis pigmentosa [ 143 ] or dystonia [ 144 ]. Horizontal microsaccadic oscillations, interfering with smooth pursuit, saccades, and optokinetic nystagmus as well as hyperventilation-induced ocular flutter and hippus have been described as well [ 145 ].…”