Supranuclear Paralysis of Vertical Gaze

This case was presented to the Clinical Eye Movement Society at the American Neurological Association Meeting in October 2007. The patient is a healthy, 36 year old Lieutenant Commander in the Coast Guard who was last seen perfectly well at 2 a.m. on the day of admission. He awoke in the morning around 9 a.m. having over slept - a rare event for him and noticed immediately that his vision was "all askew" due to vertical diplopia. On his way to work he felt tilted to the left and a little off balance tending to veer to the left. His left face was slightly drooped and the left arm and leg were clumsy. When he arrived at the office he was unable to type. The fingers of his left hand were clumsy and failed to hit the keys accurately. He complained of fatigue and attributed this to working almost non-stop for two weeks at his computer to design a software program. Symptomatic Inquiry: Negative for headache, vertigo, speech disturbance, chest pain, shortness of breath or palpitations. Family History: Negative for vascular and neurological disease. On examination: BP 110/60, heart rate 53, normal rhythm. General Neurological Examination: Mild left facial droop No pronator drift and normal motor strength throughout Intact coordination with no dysmetria Deep tendon reflexes 1+ symmetric Plantar responses flexor Sensory system intact Ocular motility showed: A global supranuclear paralysis of vertical up and downgaze (only 15 degrees up, 5 degrees down from midposition) Vertical saccadic pursuit movements were limited over a similar range of eye movement. Convergence normal Horizontal gaze full Gaze evoked nystagmus to the right Horizontal gaze to the left, mild abduction weakness Ocular dysmetria: Right gaze to center overshoot (hypermetric) Left gaze to center undershoot (hypometric) Vertical oculocephalic movements intact Bell's reflex intact (eyes deviated up under tightly closed lids). Additional eye signs: A left ocular tilt reaction (OTR) is a central vestibular disorder involving the vertical vestibulo-ocular reflex in the roll plane. The key to the diagnosis of an OTR is the combination of a 1.Lateral head tilt to the left in this case. 2.Hypertropia of the undermost eye, left eye, 3.Hypertropia of the contralateral right eye. 4.Fundus photography completes the triad and shows cyclodeviation of the eyes towards the head tilt (excyclotropia of the hypotropic eye; incyclotropia of the hypertropic eye). This patient did not complain of any perceptual tilt of the visual scene or crossed double images. Optokinetic nystagmus (OKN) with rotation of the stripes down, showed convergence retraction nystagmus as he attempted to look up to refixate the stripes. The pupils were abnormal - 5 mm OU with light/near dissociation. Investigations: Initially, there was concern for a diagnosis of endocarditis given the history of recent dental work and night sweats. Blood Studies: Complete blood count and erythrocyte sedimentation rate normal. Blood cultures x 3 negative. Hemocoagulable panel normal. Echocardiogram: A transthoracic and transesophageal echo revealed a patent foramen ovale with left to right shunting by Doppler. Chest x-ray and CT: Showed a right pulmonary embolus and lower lobe infarct. Abdominal/pelvic CT: Normal. Ultrasound and MRV of the lower extremities and pelvis revealed no deep vein thrombosis (DVT). CTA of the head showed: 1.Hyperdensity in the right anterior medial thalamus, consistent with infarction. 2.No hemodynamically significant lesion in the cervical or intracranial arterial circulation 3.Three mm. hypodense nodule in the posterior aspect of the left lobe of the thyroid gland Brain MRI perfusion imaging (7/16/07): 1.A DWI hyperintensity and corresponding ADC hypointensity in the right anterior medial thalamus extending into the right parasagittal midbrain adjacent to the red nucleus. (Figure 1) 2.A very faint FLAIR hyperintensity corresponding to the restricted diffusion image in the right thalamus. Diagnosis: Unilateral embolic infarction in the right anterior medial thalamus extending into the right mesencephalon adjacent to the red nucleus. Treatment: Warfarin sodium (Coumadin) 5 MG. p.o. q. p.m. Enoxaparin (Lovenox) 70 MG SC b.i.d. Discharge Diagnosis: 1.Discreet unilateral embolic infarct of the right paramedian thalamus and upper midbrain in the distribution of the posterior thalamo-subthalamic paramedian artery - the artery of Percheron (1). 2.A clinically silent right lower lobe pulmonary embolus. 3.Patent foramen ovale (PFO) with left to right shunting. Prognosis: The patient was advised that the prognosis for full recovery of his eye movements was excellent. On day 5, the vertical diplopia had resolved with complete resolution of the OTR and skew deviation. Two months later further recovery was noted with: 1.Full vertical gaze with slow vertical saccades most marked on up gaze 2.Looking down from a full upgaze position the eyes lateropulsed to the left or converged. 3.Beats of convergence nystagmus were provoked by a fast upward saccade and OKN with the stripes down. 4.He complained of persistent somnolence and had adopted the habit of setting 3 alarm clocks to wake him each morning. The patient returned 3 months after his acute stroke for closure of the PFO. On examination three weeks later, there was no change in his eye movements. He complained of excessive day time sleepiness. Brain MRI showed a rounded focus of T2 hyperintensity along the medial aspect of the right thalamus at the same location as a lesion with restricted diffusion on the prior brain MRI. (Figures 2A, B and C). See also: http://content.lib.utah.edu/cdm/ref/collection/ehsl-shw/id/299