Eye motor manifestations in children with neurometabolic disorders

Abstract

Neurometabolic diseases are complex group of rare neurogenetic disorders, which are difficult to diagnose. Patients may have toxic metabolite accumulation, inadequate energy supply, or neurotransmitter deficiency, resulting in a variety of clinical manifestations and severity with enzyme activity or transporter function defects. Multiple organ involvement is frequently seen, among which neurological symptoms and signs are one of the most encountered problems. Ocular motor problems deserve special attention for it occurs in some inborn error of metabolism. Furthermore, some are early signs or characteristic findings of certain diseases, such as the gaze palsy in Niemann-Pick disease type C and Gaucher disease or oculogyric crisis in neurotransmitter diseases. Early recognition and intervention are important for better prognosis in treatable neurometabolic disorders. In addition, ways to evaluate and describe eye movement problems also help to demonstrate the severity or clinical progression for those diagnosed with certain neurometabolic diseases. However, the complexity of eye movement and ocular motor control renders our clinical observation, recording and even anatomic localization of abnormal eye movements. Clinicians are more likely to detect early signs and unravel problems by gaining awareness of abnormal eye movement. This study amied to approach neurometabolic diseases in children via eye motor manifestations.

Keywords: Children; Eye movement; Movement disorders; Neurometabolic diseases; Nystagmus.