Lesions affecting the dorsal midbrain can result in a constellation of ocular findings such as vertical gaze disturbances, convergence retraction nystagmus, light-near dissociation of pupils, and eyelid retraction.1,2 Although bilateral superior oblique palsy can occur after a stroke, its occurrence secondary to nontraumatic brainstem hemorrhage is extremely rare.3 We report a combination of dorsal midbrain syndrome and bilateral superior oblique palsy following brainstem hemorrhage.
A 43-year-old man noted sudden onset of binocular vertical and torsional diplopia subsequent to a stroke 2 years prior to presentation. He complained of oscillopsia more pronounced in upgaze along with an anomalous chin-down position since the stroke. He was receiving anticoagulant therapy for coagulopathy at the time of the stroke and underwent a right frontal ventriculoperitoneal shunt for acute hydrocephalus secondary to the intracranial bleed.
Uncorrected visual acuity was 20/25 OU. Pupils were 3 mm in both eyes with a light-near dissociation. A 20° chin-down position was noted in primary gaze. Motility examination showed 30 prism diopter (Δ) esotropia with 4 Δ right hypertropia in primary position, 20 Δ esotropia with 7 Δ right hypertropia in upgaze, and 35 Δ esotropia with 4 Δ right hypertropia in downgaze. In right gaze, there was 20 Δ esotropia with 9 Δ left hypertropia, and in left gaze, there was 20 Δ esotropia with 10 Δ right hypertropia. Right head tilt revealed 20 Δ esotropia with 12 Δ left hypertropia, and left head tilt showed 25 Δ esotropia with 4 Δ left hypertropia. There was reduced depression in adduction and reduced elevation in both abduction and adduction in both eyes. Double Maddox rod test showed 30° excyclotorsion OS in primary gaze increasing to 42° in downgaze. An eyelid retraction and convergence retraction nystagmus was noted in attempted upgaze with hypometric vertical saccades both in upgaze and downgaze (Figure 1).
Preoperative photographs of the subject in 9 diagnostic positions of gazes demonstrating underelevation in both adduction and abduction and underdepression in adduction in both eyes. A V pattern esotropia along with an alternating hypertropia in side gazes is also seen.
Sagittal noncontrast magnetic resonance imaging (Figure 2A) performed 3 months prior to ocular examination revealed prior brainstem hemorrhage extending vertically from the posterior pontomesencephalic junction into the cerebral peduncle with hemosiderin staining of the superior cerebellar peduncle. Axial contrast magnetic resonance imaging (Figure 2B) showed enhancement along margins of the hemorrhagic cleft, which was felt to be an underlying occult vascular malformation/sequelae from prior hemorrhage. The patient underwent bilateral superior oblique tucking with bilateral medial rectus recession, which improved torsion in primary gaze, although moderate esotropia and excyclotorsion persisted in downgaze.
Magnetic resonance imaging (MRI) of the head. A, Sagittal T1 MRI scan without contrast. It shows evidence of prior brainstem hemorrhage (arrowheads) extending vertically from the posterior pontomesencephalic junction into the cerebral peduncle with hemosiderin staining of the superior cerebellar peduncle. B, Axial T1 MRI scan with contrast. Following administration of contrast, there was enhancement along the margins of the hemorrhagic cleft (arrow).
Dorsal midbrain syndrome can be due to a number of conditions such as pineal region neoplasms,1 obstructive hydrocephalus, arteriovenous malformations, multiple sclerosis, mesencephalic hemorrhages, or dorsal midbrain infection. Spontaneous nontraumatic, nonhypertensive, midbrain hemorrhage is an uncommon cause of dorsal midbrain syndrome and may be due to an underlying occult vascular malformation.4
Bilateral superior oblique palsies are usually congenital or the consequence of a closed head trauma; those secondary to a nontraumatic brainstem hemorrhage are extremely rare.4 Although an isolated case of dorsal midbrain syndrome and bilateral superior oblique palsy has been reported before,4 the association of the two following a nontraumatic, nonhypertensive brainstem hemorrhage is extremely rare.
Correspondence: Dr Bhola, Department of Ophthalmology, University of Iowa Hospitals and Clinics, Iowa City, IA 52246 (firstname.lastname@example.org).
Financial Disclosure: None reported.
Bhola R, Olson RJ. Dorsal Midbrain Syndrome With Bilateral Superior Oblique Palsy Following Brainstem Hemorrhage. Arch Ophthalmol. 2006;124(12):1786-1788. doi:10.1001/archopht.124.12.1786