Prenuclear Paresis of Homolateral Inferior Rectus and Contralateral Superior Oblique Eye Muscles

Internuclear Ophthalmoplegia Associated with Ipsilateral Downbeat Nystagmus and Contralateral Incyclorotatory Nystagmus

“…These fibers transmit signals from the vestibular nucleus to the ocular muscle nuclei that maintain vertical eye deviations and vestibulo-ocular reflex. In the monkey, lesions of these fibers have been shown to produce a gaze paretic nys tagmus [8] similar to that seen in the present case as well as in the case of Meienberg et al [12]. Bilateral interruption ofthe medial lon gitudinal fasciculus in the monkey produced associated nystagmus, i.e., vertical gaze pa retic nystagmus in both eyes [7], In our patient, the unusual association of left internuclear ophthalmoplegia with downbeat nystagmus of the involved eye and incyclorotatory nystagmus of the contralat eral eye indicates selective interruption of the tonic fibers, as shown in figure 4.…”

“…Myasthenia gravis is largely excluded in our case by the results of re peated Tensilon tests, other clinical exami nations using EOG velocity, EMG record ings and by spontaneous remission within 3 months [18]. The case showed a strong re semblance to that reported by Meienberg et al [12], that is, prenuclear paresis of the ascending tonic fibers of the homolateral inferior rectus and interruption of the con tralateral superior oblique eye muscles be fore entering the medial longitudinal fasci culus. The present case, however, was asso ciated with apparent left internuclear oph thalmoplegia.…”

“…A case of ocular motor disturbance that showed a strong resemblance to the case reported by Meienberg et al [12] was ob served. In this case, the disorder was accom panied by internuclear ophthalmoplegia, skew deviation and exotropia in the primary position.…”

“…Recently, however, attention has been directed at vertical abnormalities in patients with internuclear ophthalmoplegia, and several clinical papers have been pre sented [1,6]. The lesion causing such vertical abnormality might be located at the pathway between the vestibular nuclei and the oculo motor nuclear complex [4,5,9,11,14], Re cently, Meienberg et al [12] reported a case of ocular motor syndrome with paresis of the homolateral inferior rectus and contralat eral superior oblique muscles. This patient had monocular downbeat nystagmus and contralateral incyclorotatory nystagmus without internuclear ophthalmoplegia.…”

Supranukleäre und internukleäre Augenbewegungsstörungen

“…Auch kongenitale Formen dieses Syndroms -meist verbunden mit ipsilateraler kongenitaler Ptose -sollen häufig Ausdruck einer supranukleären Störung sein (lOS). Ein Fall eines etwa entsprechenden Syndroms bei Blickwendung nach unten wurde von Meienberg et al (213) mitgeteilt. Die Abgrenzung von einer Hertwig-Magendieschen Schielstellung ist gegeben durch die regelrechte Augenstellung in Primärposition und der erst beim Blick nach oben entstehenden Vertikaldivergenz.…”