Body Lateropulsion as a Presenting Symptom of Rostral Paramedian Midbrain Syndrome

Abstract

logical examination, the day after the onset of symptoms, she fell to the right when attempting to stand with her eyes open. She could not sit without falling to the right side. She made no attempt to prevent these falls by widening her stance. In addition to falling, there was a mild limitation in eye movements with adduction and depression, and incomplete ptosis. Both pupils responded to light and accommodative stimuli. Spontaneous or gaze-evoked nystagmus was undetectable with or without Frenzel’s glasses. There was no limb ataxia on finger-to-nose and heel-to-shin testing. Dear Sir, Lateropulsion of the body is the occurrence of an irresistible fall in individuals without vertigo, paresis, sensory loss, or cerebellar deficits [1] . It is a well-known clinical feature of the lateral medullary infarction, but other lesions with cerebellum, midbrain, thalamus, and pons could also result in body lateropulsion [2–6] . Body lateropulsion is usually associated with other neurological symptoms or signs, which vary according to the structures involved. Vestibular dysfunction in the roll plane of the vestibulo-ocular reflex is responsible for body lateropulsion in most cases [2] . There have been only few reports [7, 8] on body lateropulsion as a presenting symptom of rostral midbrain infarction. Furthermore, previous reports [7, 8] have not emphasized the vestibular dysfunction as a possible mechanism of body lateropulsion and did not perform a quantitative posturography test to investigate the mechanism of gait dysfunction. I present a patient who had body lateropulsion as the presenting feature of a small infarct in the rostral paramedian midbrain and discuss the possible mechanism of body lateropulsion at the level of the rostral midbrain.