Contralateral axial lateropulsion and ocular tilt reaction in a cerebello-lateral medullary-spinal stroke

Abstract

On 26 September 2010 a hypertensive, 66 year old male presented with an acute vestibular syndrome and headache of 4-h duration. Exam showed a crossed left face/right body hypoanalgesia and mild right axial lateropulsion. Initial brain magnetic resonance imaging (MRI) the same day showed acute infarction of the left cerebellar tonsil, gracile, and biventral lobe and of the caudal lateral medulla. He improved, but on 10 October 2010 developed worsening imbalance and could not sit without support due to severe right axial lateropulsion. On exam the next day, he had a right ocular tilt reaction (OTR), with a 3-prismdiopter hypotropic, excyclotropic right eye and low amplitude gaze evoked left-beat nystagmus. His subjective visual vertical (SVV) deviated 16 to the right. He had a normal head impulse test. New findings included profound absence of position and vibratory sense in the left upper and lower extremities, sensory ataxia, and mild left hemiparesis. Crossed hypoanalgesia was unchanged. Right axial lateropulsion corrected easily, without pushing behavior. Examination was otherwise unremarkable. Postural vertical (PV) and haptic vertical (HP) were not tested. On 15 October 2010, repeat brain MRI (Fig. 1) was unchanged, and cervical spine MRI (Fig. 2) revealed a postero-lateral cervical spinal cord stroke and altered signal within the left vertebral artery compatible with dissection. Follow-up examination 9 months later showed improved right axial lateropulsion, rightward OTR and 12 SVV deviation. He regained the ability to sit without support but could not stand. Findings for our patient provide an opportunity to assess the impact of near simultaneous altered gravitational perception, unilateral proprioceptive loss, and impaired postural compensation. To our knowledge, one previous case of a stroke involving arterial topography similar to our case has been reported [1]. These two cases also shared some clinical findings, representing a combination of lateral medullary (LMS), Opalski [2], and posterior spinal artery syndromes. Unique findings in our case, however, include contralateral body lateropulsion and OTR, and lengthy duration of axial balance impairment.