• Written By: Jennifer Doyle, MD

    This systematic literature review of patients with infantile-onset saccade initiation delay (ISID) found that examining the direction of head thrusts and slow phases of optokinetic response may help identify possible sites of brain MRI abnormalities.

    They reviewed English medical literature between 1952 and 2012 and found 67 studies that included possible ISID. The final analysis included 91 patients (age range, 3 months to 45 years) divided into three MRI groups: normal (n = 55), supratentorial abnormalities (n = 17) and infratentorial abnormalities (n = 19).

    Patients with horizontal head thrusts tended to be in the normal MRI or infratentorial abnormality groups. Patients with supratentorial abnormalities more often demonstrated vertical head thrusts.

    The slow phases of optokinetic response were more frequently normal in patients with normal MRIs, while those with supratentorial or infratentorial MRI abnormalities tended to have impaired OKR slow phases.

    Other neuro-ophthalmological, neurological and developmental features were similar among patients in the three groups. The authors say this similarity likely reflects the widespread central nervous system dysfunction in ISID patients.