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Show ORIGINAL CONTRIBUTION Paroxysmal Tonic Downgaze in Two Healthy Infants Darcy H. Wolsey, MD, MPH and Judith E. A. Warner, MD Abstract: A 5- month- old boy and 7- month- old girl had episodes of downward eye deviation starting at age 5 months, lasting seconds to minutes, and associated with stiffening of the extremities in one case and grasping, flailing upper extremity movements and retroflexion of the head in the other. There were no other clinical abnormalities. Electroencephalography and MRI were normal. The episodes stopped after 6 to 12 weeks and there have been no sequelae. This idiopathic condition resembles paroxysmal tonic upgaze in infancy. Until further documentation clearly establishes that this phenomenon is benign, evaluation with MRI and electroencephalography is indicated. (/ Neuro- Ophthalmol 2006; 26: 187- 189) Supranuclear disturbances of gaze have been reported to occur in normal healthy infants. Hoyt ( 1) described 5 healthy newborns with sustained downgaze while awake. These symptoms all resolved by 6 months with no residual neurologic sequelae. Ouvrier and Billison ( 2) described older infants with upward deviation of the eyes that occurred for brief episodes, which they labeled " paroxysmal tonic upgaze" ( PTU). Most of these cases also resolved without clinical consequences. We present two cases of brief episodes of downgaze in healthy infants that appear to have features in common with PTU. CASE REPORTS Case # 1 A 5- month- old healthy boy presented with paroxysmal tonic downgaze. The patient was born at full term and had normal development. The spells started 7 days before presentation, each episode lasting between 10 seconds and Moran Eye Center, University of Utah, Salt Lake City, Utah. Address correspondence to Darcy H. Wolsey, MD, MPH, Moran Eye Center, University of Utah, 65 North Medical Drive, Salt Lake City, UT 84124; E- mail: darcy. wolsey@ hsc. utah. edu 1 minute. He had many spells per day that seemed to occur more frequently when he was supine. The longer spells were associated with stiffening of upper and lower extremities without any impairment in consciousness. He was diagnosed with an ear infection at the time the spells started. The spells were witnessed by a primary care physician and an emergency room physician. The physicians and his mother described the spells as consisting of extreme downgaze with some adduction of both eyes. Ophthalmologic examination disclosed that he fixed and followed equally with each eye. He had normal ocular alignment and full extraocular movements without nystagmus. All other aspects of the examination were unremarkable. The patient had no spells during examination despite lying supine for 1 hour. On one occasion, when the left eye was occluded, the eyes crossed and depressed briefly. This was reportedly similar to the episodes but much briefer and less extreme. Neurologic examination demonstrated a bright, alert, babbling child in excellent humor. He had normal muscle tone and strength, and all four extremities moved spontaneously. Deep tendon reflexes were normal. Evaluation included a normal electroencephalogram ( EEG), brain CT, and brain MRI. The manifestations resolved within 6 weeks of onset. He did not develop any neurologic problems in the subsequent 12 months. Case # 2 A 7- month- old healthy girl born at full term after a normal pregnancy and delivery presented with paroxysmal tonic downgaze ( Fig. 1). These manifestations started at age 5 months with episodes of downgaze lasting approximately 10 seconds. Associated movements included grasping and flailing of the arms and throwing back of the head. The spells became longer and more frequent 3 weeks after they started, lasting 30 to 60 seconds, with several episodes occurring over the course of 5 minutes. The episodes began decreasing in frequency 2 weeks later and resolved within 3 months. There was no associated illness or vaccination. Our ophthalmologic examination disclosed that she fixed and followed equally with each eye and with both J Neuro- Ophthalmol, Vol. 26, No. 3, 2006 187 J Neuro- Ophthalmol, Vol. 26, No. 3, 2006 Wolsey and Warner FIG. 1. Case # 2 is a 7- month- old girl with extreme downgaze. The downgaze occurred in episodes that initially lasted 10 seconds but later increased in duration to 60 seconds. The episodes resolved spontaneously. eyes together. All other aspects of the ophthalmologic examination were also normal. Neurologic examination showed normal strength and tone of all extremities, normal deep tendon reflexes, and no ataxia. Brain MRI was normal. Because her ophthalmic manifestations appeared to be resolving, no EEG was performed. She had developed no neurologic abnormalities after 18 months of follow up. DISCUSSION The two patients we describe had an episodic downward gaze disturbance that could be called paroxysmal tonic downgaze. The infants displayed other abnormal body movements during the episodes, but their EEG and brain imaging were normal and the episodes resolved without the appearance of any abnormalities over a prolonged follow up. Episodes of tonic downward deviation have been previously reported ( 1,3- 6), but our cases do not precisely fit these descriptions. There have been three reported syndromes of downgaze in infancy. Hoyt ( 1) examined 242 healthy neonates and described 5 with a downgaze abnormality. These 5 patients had persistent tonic downward deviation of the eyes while awake and normal oculocephahc responses and a normal Bell phenomenon while asleep. The downgaze had disappeared by 6 months of age without any clinical sequelae. Walsh and Hoyt ( 3) also described two infants with similar downgaze episodes, but details in their report are sparse. Our two patients with downward deviation of the eyes were older at the time of onset of the gaze abnormality. Also, our patients' downgaze occurred in brief episodes lasting seconds, whereas Hoyt's cases had downgaze during all waking hours. Kleiman et al ( 4) described a second syndrome of downward gaze deviation lasting seconds and occurring 2 to 3 months after birth in five preterm infants ( 22- 28 weeks gestation). These episodes also resolved and the infants appeared to be developing normally. Very similar downgaze episodes have been described in older infants ( age 2- 8 months) with severe developmental disabilities ( 5). Although the episodes are very similar to those of our patients, they occurred in preterm infants or in infants with severe neurologic disturbances. A third paroxysmal downward eye deviation in infancy is the " eye- popping" reflex ( 6). This phenomenon is a short- lived ( 3- 10 seconds) downward deviation of the eyes associated with dramatic lid retraction occurring reliably after sudden change of illumination from light to dark. This reflex was found in 29% of normal infants in the neonatal period increasing to a peak of 78% in at 14 to 18 weeks of age. Our patients did not have lid retraction or episodes triggered by sudden exposure to darkness. Our two cases of downgaze spells do not fit these previously described downgaze disorders. They are, however, similar to the upward deviations first described by Ouvrier and Billson in 1988 ( 2) as " paroxysmal tonic upgaze." Paroxysmal tonic upgaze of childhood is characterized by sustained conjugate upward deviation of the eyes with downbeating saccades in attempted downgaze ( 2,7). Neurologic, ophthalmic, and radiologic evaluations were all normal and there was no evidence of seizure activity on EEG ( 2,8). Onset has been described in children age 1 week to 7 years but most often before age 1 ( 2,7- 9). It often occurs shortly after illness or vaccination. Symptoms are relieved by sleep ( 9). Most cases of PTU resolve without clinical consequences, but neurologic abnormalities have been described, including ataxia, developmental delay, amblyopia, and strabismus ( 7- 9). In 2005, Ouvrier ( 9) reviewed 45 cases of PTU from personal experience and from the literature and found 50% had mild cognitive or language problems, approximately 25% had residual ataxia, and approximately 20% to 25% had other ocular motility problems such as strabismus or nystagmus. Our two cases have had normal ocular and neurologic development since resolution of the symptoms. More cases of paroxysmal tonic downgaze will need to be followed to determine if any will have subsequent neurologic abnormalities as seen with some of the PTU cases. The pathogenesis of these transient gaze disturbances is not understood. Some hypothesize that the transient deviation may be the result of immature myelination of the corticomesencephalic vertical gaze pathways ( 3). The transient nature of the disorders, especially in older infants, may result from temporary failure of cortical compensation when a stressor such as illness is present ( 6,9). Because downward deviation of the eyes has been associated with hydrocephalus, coma of various causes, and seizures ( 5), MRI scanning and EEG are indicated in the investigation of paroxysmal tonic gaze deviations in infants. 188 © 2006 Lippincott Williams & Wilkins Paroxysmal Downgaze in Infants J Neuro- Ophthalmol, Vol. 26, No. 3, 2006 REFERENCES 1. Hoyt CS, Mousel DK, Weber AA. Transient supranuclear disturbances of gaze in healthy neonates. Am J Ophthalmol 1980; 89: 708- 13. 2. Ouvier RA, Billson F. Benign paroxysmal tonic upgaze of childhood. J Child Neurol 1988; 3: 177- 80. 3. Walsh FB, Hoyt WF ClinicalNeuro- Ophthalmology. Vol I. Baltimore: Williams & Wilkins; 1969: 230. 4. Kleiman MD, DiMario FJ Jr, Leconche DA, et al. Benign transient downward gaze in preterm infants. Pediatr Neurol 1994; 10: 313- 6. 5. Yokochi K. Paroxysmal ocular downward deviation in neurologically impaired infants. Pediatr Neurol 1991; 7: 426- 8. 6. Perez RB. The eye- popping reflex of infants. J Pediatr 1972; 81: 87- 8. 7. Verrotti A, Trotta D, Blasetti A, et al. Paroxysmal tonic upgaze of childhood: effect of age- of- onset on prognosis. Acta Paediatr 2001 ; 90: 1343- 5. 8. Hayman M, Harvey AS, Hopkins IJ, et al. Paroxysmal tonic upgaze: a reappraisal of outcome. Ann Neurol 1998; 43: 514- 20. 9. Ouvrier R, Billson F. Paroxysmal tonic upgaze of childhood- a review. 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