Dissociated vertical deviation and head tilts.
BACKGROUND
The association of anomalous head posture and dissociated vertical deviation does not seem to be appreciated, as evidenced by the paucity of literature linking these two conditions.


METHODS
The series describes 14 patients who had an anomalous head posture and dissociated vertical deviation. The assumed head tilts appeared to decrease the magnitude and improve the motor control of dissociated vertical deviation.


RESULTS
Twelve of 14 patients tilted their heads contralateral to the eye with the dissociated vertical deviation, or away from the eye with a larger amount of dissociated vertical deviation if the disorder was bilateral. Two patients tilted their heads to the same side as the eye with the dissociated vertical deviation. Forced head tilt-testing in the opposite direction showed an increase in the magnitude of the dissociated vertical deviation or poorer control of the deviation. Dissociated vertical deviation was not related to oblique muscle dysfunction. Peripheral fusion was demonstrated in 10 patients, as evidenced by low-grade stereopsis or Worth 4 dot fusion at near. One patient did not show any demonstrable fusion with conventional tests. Another did not show evidence of stereopsis, but Worth 4 dot testing was not performed. Two other patients were too young to cooperate with sensory testing. Anomalous head posture was controlled or minimized after the control of the dissociated vertical deviation by surgery in four patients. Two patients showed improved stereopsis after surgery for dissociated vertical deviation.


CONCLUSIONS
Dissociated vertical deviation should be included in the differential diagnosis of an ocular cause of head tilts. Forced contralateral head tilttesting will confirm whether dissociated vertical deviation is the cause if motor control of the dissociated vertical deviation worsens or becomes manifest rather than latent. The presence of an anomalous head posture in patients with dissociated vertical deviation can be improved with strabismus surgery.
Santiago
A P
AP
Department of Ophthalmology, Jules Stein Eye Institute, University of California, Los Angeles 90095, USA.
Rosenbaum
A L
AL
D000328:Adult; D002648:Child; D002675:Child, Preschool; D003867:Depth Perception; D003937:Diagnosis, Differential; D005260:Female; D005403:Fixation, Ocular; D019416:Head Movements; D006801:Humans; D007223:Infant; D008297:Male; D011187:Posture; D012683:Sensory Deprivation; D013285:Strabismus / Q000150:complications* / Q000175:diagnosis / Q000601:surgery