Vertical glaze paralysis and the rostral interstitial nucleus of the medial longitudinal fasciculus.

The rostral interstitial nucleus of the medial longitudinal fasciculus in known to participate in the generation of fast vertical eye movements in the monkey. A cell group homologous to this nucleus has been identified in the human brain. In man the nucleus lies dorsomedial to the anterior pole of the red nucleus, rostral to the interstitial nucleus of Cajal, and lateral to the nucleus of Darkschewitsch. Reconstructions of lesions in patients with different types of vertical gaze paralysis show that destruction of the rostral interstitial nucleus of the MLF bilaterally leads to an impairment of fast vertical eye movements. We propose that the nucleus participates in the production of vertical saccades and quick phases of nystagmus in man. Preservation of its integrity is not necessary for the production of vestibular compensatory eye movements in the vertical plane.