Bilateral Internuclear Ophthalmoplegia

Bilateral Internuclear Ophthalmoplegia; Upbeat NystagmusPowerPoint Presentation: Internuclear Ophthalmoplegia in Childhood: http://library.med.utah.edu/NOVEL/Wray/PPT/Internuclear_Ophthalmoplegia_in_Childhood_guest_lecture.ppt Shirley H. Wray, M.D., Ph.D., FRCP, Harvard Medical SchoolRight eye driftThis case was reported by Cogan DG and Wray SH. Internuclear ophthalmoplegia as an early sign of brain tumor. Neurology 1970; 20:629-633. The patient is Case 1. He is a 4 ½ year old boy whose parents noted that the right eye had been "drifting" for four months. On examination the only significant finding was complete and symmetrical paralysis of adduction on gaze to either side with coarse nystagmus of the abducting eye, Convergence was well performed. (Figures 1A, B and C (Pictures taken from moving film) (3)). Neurological examination was entirely normal. Clinical Diagnosis: Bilateral internuclear ophthalmoplegia (INO) The preliminary etiological diagnosis was multiple sclerosis, but the patient's very young age cast doubt on the diagnosis and he was admitted for full investigation. Skull x-rays: Revealed widening of the suture lines suggestive of chronically increased intracranial pressure (despite the absence of papilledema).. Pneumoencephalography failed to fill the ventricular system. Subsequent gas and pantopaque ventriculography disclosed symmetrical enlargement of the lateral ventricles, an expanded third ventricle, a dilatation of the anterior end of the fourth ventricle, and a block at the posterior end of the aqueduct - i.e. obstructive hydrocephalus. (Figures 2-4) Posterior fossa craniotomy revealed an inoperable tumor arising from the anterior floor of the fourth ventricle. A biopsy of the tumor was taken and a shunt inserted to bypass the aqueduct. Pathology: Histological sections were variously interpreted as consistent with a medulloblastoma or glioma. (Figure 5) The post-operative course was uneventful. Therapy: A ventriculo-peritoneal shunt was placed. The boy received radiation therapy with a total dose of 5,000 rads to the area of the mass. The spine was irradiated with 2,500 rads as a precautionary measure because of the statistical frequency of spinal seeding. Follow-up examination eleven months after completion of radiation therapy showed no change in the eye movements and only mild ataxia. Bilateral INO in childhood is rare. Cogan and I reported five other cases of internuclear ophthalmoplegia in childhood. (3) Age range 4 ½ - 17 years of age, 3 boys and 3 girls. The duration of symptoms was 9 months to 6 years. Headache, often provoked by exertion, was the presenting symptom in 4. Only one child had normal eye movements pre-operatively (Case 4). Three (Case 2, 3 and 5) had a unilateral INO and unilateral horizontal gaze palsy - a Fisher's one-and-a-half syndrome. One 17 year old boy (Case 6) with headache, increasing clumsiness and diplopia had a unilateral INO and skew deviation. The tumor was inoperable in all the children and four came to autopsy. A medulloblastoma was found in three and an infiltrating glioma in one.This little boy with a medulloblastoma and hydrocephalus had a symmetrical bilateral INO with • Paresis of adduction of the right eye on gaze left and • Abducting nystagmus of the left eye • Paresis of adduction of the left eye on gaze right and • Abducting nystagmus of the right eye • Normal convergence • Full vertical up and downgaze Clinical Features of an INO: 1. Medial rectus muscle weakness ipsilateral to the side of the lesion with paresis of adduction or adduction lag. 2. Abducting nystagmus of the eye contralateral to the lesion - Dissociated nystagmus 3. Normal convergence 4. Skew deviation - hypertropia on the side of the lesion 5. Dissociated vertical nystagmus - downbeat with greater torsional component in the contralateral eye Bilateral INO with bilateral lesions of the medial longitudinal fasciculus (MLF) may be accompanied by Gaze evoked vertical nystagmus Impaired vertical pursuit Decreased vertical vestibular response Small amplitude saccadic intrusions suggesting involvement of the brainstem adjacent to the MLF Weakness of adduction is due to impaired conduction in axons from the abducens internuclear neurons which project to the medial rectus motor neurons in the contralateral oculomotor (third nerve) nucleus. Adduction weakness is most evident during saccades and adduction lag is brought out clinically by asking the patient to look all the way to the right and all the way to the left (i.e. make large saccades) back and forth across the midline. The speed of the adducting eye depends on a strong agonist contraction. The adducting saccade may be slow and hypometric. In the abducting eye, abducting saccades are hypometric with centripetal drifts of the eye and slowing. A series of small saccades and drifts have the clinical appearance of abducting nystagmus - dissociated nystagmus. Dissociated nystagmus may be due to: 1. Impaired ability to inhibit the affected medial rectus or 2. Dissociated nystagmus reflects the brain's attempts to compensate for the adduction weakness. For further discussion review Leigh JR, Zee DS. Diagnosis and Central Disorders of Ocular Motility Chp 12:620-627 In The Neurology of Eye Movements 4th Edition Oxford University Press, New York 2006.Figues 2-4The medial longitudinal fasciculus (MLF) is a major pathway in the brainstem extending from the pons to the midbrain. The MLF carries signals for the control of horizontal eye movements For horizontal gaze: 1. The MLF contains axons from the abducens internuclear neurons and carries signals for horizontal saccades, the vestibulo-ocular reflex (VOR), and smooth pursuit. 2. These axons project to the medial rectus motor neurons in the contralateral oculomotor (third nerve) nucleus. For vertical gaze: 1. The MLF contains axons from the rostral interstitial MLF (riMLF) which carry vertical saccadic signals. 2. The MLF also contains ascending axons from the vesitibular nuclei which carry signals for the vertical VOR, smooth pursuit, gaze holding and otolith-ocular reflex. 3. Axons project to the oculomotor and trochlear (fourth nerve) nuclei, as well as the Interstitial Nucleus of Cajal. The syndrome of the MLF has been divided into anterior and posterior types. "According to Lutz, the characteristic features of anterior internuclear ophthalmoplegia are: (a) paresis or paralysis of ocular adduction upon attempted lateral gaze with preservation of adducting eye movements in ocular convergence; and (b) nystagmus exclusively present or most prominent in the abducting eye. Vertical eye movements are unaffected. Following Lutz's description, posterior internuclear ophthalmoplegia is characterized by a paresis of ocular abduction. This type would seem difficult to differentiate from an abducens nerve palsy. While there are several cases of posterior internuclear ophthalmoplegia reported in the literature, none have documented lesions involving the MLF, and the appropriateness of the term in this context has been questioned. Cogan proposed a different classification in which paresis of ocular adduction together with nystagmus in the abducting eye is characteristic of both anterior and posterior internuclear ophthalmoplegias, with convergence abolished in the former". (A discussion taken from ref (3)).Medulloblastoma Figure 5Aqueduct stenosis Obstructive hydrocephalus Brainstem tumor1. Cogan DG, Kubik CS, Smith JL. Unilateral internuclear ophthalmoplegia: report of 8 clinical cases with 1 post-mortem study. Arch Ophthalmol 1950;44:783-796. http://www.ncbi.nlm.nih.gov/pubmed/14777208 2. Cogan DG. Neurology of the Ocular Muscles, 2nd ed. Charles C. Thomas, Springfield, 1956. 3. Cogan DG, Wray SH. Internuclear ophthalmoplegia as an early sign of brainstem tumor. Neurology 1970;20:629-633. http://www.ncbi.nlm.nih.gov/pubmed/5463534 4. Cogan DG. Internuclear ophthalmoplegia typical and atypical. Arch Ophthalmol 1970-;84:583-589. http://www.ncbi.nlm.nih.gov/pubmed/5478883 5. Collard M, Eber AM, Streicher D, Rohmer F. Does posterior internuclear ophthalmoplegia exist? A report on eleven cases and the results of oculography. Rev Neurol (Paris) 1979;135:293-312. http://www.ncbi.nlm.nih.gov/pubmed/504861 6. Keane JR. Internuclear ophthalmoplegia: unusual causes in 114 of 410 patients. Arch Neurol. 2005 May;62(5):714-7. http://www.ncbi.nlm.nih.gov/pubmed/15883257 7. Leigh RJ, Zee DS. Diagnosis and Central Disorders of Ocular Motility. Chp 12;620-627. In: The Neurology of Eye Movements 4th Edition. Oxford University Press, New York 2006. 8. Lutz A. Ueber die bahnen der blickwendung und deren dissoziierung: Nebst mitteilung eines falles von ophthalmoplegiainternuclearis anterior in verbindung mit dissoziierung der bogengaenge. Klin Monatsbl. Augenheilkd 1923;70:213-235. 9. Smith JL, Cogan DG. Internuclear ophthalmoplegia: a review of 58 cases. Arch Ophthalmol 1959;61:687-694. http://www.ncbi.nlm.nih.gov/pubmed/13636562 10. Strominger MB, Mincy EJ, Strominger AI, Strominger NL. Bilateral internuclear ophthalmoplegia with absence of convergence eye movements. Clinico-pathological correlations. J Clin Neuro-ophthalmol 1986,6:57-65. http://www.ncbi.nlm.nih.gov/pubmed/3009554 11. Topilow HW. Posterior internuclear ophthalmoplegia of Lutz. Ann Ophthalmol 1981;13:221-225. http://www.ncbi.nlm.nih.gov/pubmed/7247181 12. Troost BT, Martinez J, Abel LA, Heros RC. Upbeat nystagmus and internuclear ophthalmoplegia with brainstem glioma. Arch Neurol 1980;37:453-456. http://www.ncbi.nlm.nih.gov/pubmed/738749