Keane J R
Arch Neurol. 1979 Jan;36(1):13-5. doi: 10.1001/archneur.1979.00500370043006.
Of 100 consecutive, adult, hospitalized inpatients with acquired unilateral oculosympathetic palsy, in 63 the central neuron was involved-usually due to strokes; in 21, tumor or trauma affected the preganglionic neuron; and in 13, postganglionic damage was sustained from a variety of causes. The preponderance of first neuron involvement by stroke is in part a reflection of patient sampling, but emphasizes the fact that central causes of Horner's syndrome are common.