“….when an ophthalmologist is confronted by the sudden onset of trochlear nerve palsy in a patient without a history of trauma, central nervous system pathology must be considered," yet the cases of the 7 patients described, who presented at ages 10 through 19 years, were ultimately attributed to presumed minor trauma or decompensated congenital conditions. 2 In younger children it is often impossible to be certain of the congenital onset or clinical course, and thus of the benign nature of the problem (although even congenital superior oblique paresis may, rarely, be a sign of more extensive pathology 3 ), which raises the question of when to pursue further investigation in cases of indeterminate etiology.…”