Show pageOld revisionsBacklinksBack to top This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong. ====== Paroxysmal Tonic Gaze Vertical Gaze Phenomena of infancy ====== see also: [[tonic_downgaze_children|Paroxymsal Tonic DownGaze]] Below is the response formatted in DokuWiki syntax. Since source URLs were not provided in the retrieved citations, the link targets are left as placeholders for insertion. ==== Benign Tonic Upgaze vs. Tonic Downgaze in Infants ==== * Benign (paroxysmal) tonic upgaze and paroxysmal tonic downgaze of infancy are two distinct entities * Defined by opposite directions of vertical eye deviation and by different clinical courses, associations, and workup implications. === Benign (paroxysmal) tonic upgaze (PTU) === * Characterized by episodes of **sustained conjugate upward deviation of the eyes**, with compensatory neck flexion (chin-down posture) and **incomplete/down-beating saccades on attempted downgaze**; horizontal eye movements are normal and consciousness is preserved. * Onset is typically within the first year (mean age of onset ~5–6 months, though reported from the first week to age 7). * Features include **diurnal fluctuation, relief with sleep, exacerbation by febrile illness/fatigue, and frequently associated ataxia**. * Historically considered benign with eventual resolution, but the label is misleading: substantial proportions have **developmental delay, cognitive dysfunction, or abnormal neurological findings**, and it is increasingly recognized as part of a neurodevelopmental spectrum with identified genetic bases, especially **CACNA1A** (also KCNA1, FGF14, GRID2). One acetazolamide-responsive form is CACNA1A-related. === Paroxysmal tonic downgaze of infancy === * Characterized by **tonic downward deviation of the eyes** (often slightly exotropic), with intermittent upward saccades — the mirror image of PTU. Also described as "benign positional vertical opsoclonus," often occurring in the **supine position**. * An idiopathic/benign form occurs in term infants, presents very early (days to ~12 weeks), and **resolves spontaneously (often by ~6 months) with normal development and neuroimaging**; a comprehensive workup may be unnecessary in classic benign cases. * However, symptomatic tonic downgaze is strongly associated with **CNS injury** — particularly periventricular leukomalacia and hypoxic-ischemic injury in preterm infants, correlating with subcortical visual loss, spastic diplegia/quadriplegia, and developmental delay. It can also be the presenting sign of serious treatable disease (e.g., biotin-thiamine-responsive basal ganglia disease, so context-dependent evaluation is essential. === Key distinctions === ^ Feature ^ Benign tonic upgaze (PTU) ^ Tonic downgaze of infancy ^ | Eye deviation | Sustained upward, with chin-down neck flexion | Sustained downward, often exotropic/supine-triggered | | Saccade correction | Down-beating saccades on attempted downgaze | Intermittent upward saccades | | Typical onset | First year, mean ~5–6 mo | Very early (days–12 wk) in benign form | | Prognosis/associations | Often part of neurodevelopmental spectrum; CACNA1A and other genes | Benign form resolves; symptomatic form linked to PVL/HIE, metabolic disease | Both are on the differential of nonepileptic paroxysmal eye-movement phenomena of infancy and can be [[detecting_seizures_during_pediatric_eye_exam|mistaken for seizures]], so video documentation and normal EEG during events are useful in distinguishing them from epilepsy. ===== References ===== - [[https://pubmed.ncbi.nlm.nih.gov/38175838|Lazar SM, Abid F. Pearls & Oy-Sters: CACNA1A-Related Paroxysmal Tonic Upgaze With Ataxia Responsive to Acetazolamide. Neurology. 2024]] - [[https://pubmed.ncbi.nlm.nih.gov/29095389|Kartal A. Paroxysmal Tonic Upgaze in Children: Three Case Reports and a Review of the Literature. Pediatr Emerg Care. 2019]] - [[https://onlinelibrary.wiley.com/doi/10.1002/mds.22944|Bonnet C, Roubertie A, Doummar D, et al. Developmental and benign movement disorders in childhood. Mov Disord. 2010]] - [[https://pubmed.ncbi.nlm.nih.gov/29926469|Humbertclaude V, Krams B, Nogue E, et al. Benign Paroxysmal Torticollis, Benign Paroxysmal Vertigo, and Benign Tonic Upward Gaze Are Not Benign Disorders. Dev Med Child Neurol. 2018]] - [[https://pubmed.ncbi.nlm.nih.gov/9546334|Hayman M, Harvey AS, Hopkins IJ, et al. Paroxysmal Tonic Upgaze: A Reappraisal of Outcome. Ann Neurol. 1998]] - [[https://pubmed.ncbi.nlm.nih.gov/24101752|Rodan LH, Tein I, Buncic R. Clinical Reasoning: A Case of Abnormal Eye Movements in an Infant: More Than Meets the Eye. Neurology. 2013]] - [[https://pubmed.ncbi.nlm.nih.gov/28903967|Sternfeld A, Lobel D, Leiba H, et al. Long-Term Follow-Up of Benign Positional Vertical Opsoclonus in Infants: Retrospective Cohort. Br J Ophthalmol. 2018]] - [[https://pubmed.ncbi.nlm.nih.gov/36657988|Maney K, Pizoli C, Russ JB. Child Neurology: Infantile Biotin Thiamine Responsive Basal Ganglia Disease: Case Report and Brief Review. Neurology. 2023]]