The Bell’s phenomenon in newborns

Objective: This study was undertaken to detect thecourse of Bell’s phenomenon development in full andpre-term babies.Methods: Three hundred healthy newborns (150 fullterm and 150 pre-term) born at Prince Rashid BinAl-Hasan military hospital from the first of January 2000to 31st of December 2000 in Irbid in the north of Jordan,were randomly selected and included in the study. Bell’sphenomenon response was graded according to themovement of the eye as: 0 = no movement, 1 = minimalmovement (the pupil still visible), 2 = full movement (thepupil is covered by the eyelid). The Bell’s PhenomenonScoring System (BPSS) was chosen to score the eyemovement. The newborn was examined during the firstweek of life and then repeated at 4 weekly intervals, for 5months for the full term babies and for 2 months for thepre-term babies.Results: In the full term group only 25/150 (16.7%) ofthe newborns showed full response (BPSS-2) during thefirst week of life and this number increased to 133/150(88.7%) at the age of 5 months. None of the pre-termgroup showed the Bell’s phenomenon response (BPSS-0)during the first week of life and only 21/150 (14%) hadfull response (BPSS-2) at 4 weeks. At the age of 2months approximately 51/150 (34%) developed fullresponse (BPSS-2).Conclusion: The development of Bell’s phenomenonreflex reflects the maturation process of the brainstem andthe extraocular muscles related to eye elevation. It shouldbe considered as part of the routine tests undertaken byevery pediatrician and ophthalmologist during theneuro-ophthalmic examination in newborns.