Painful Oculomotor Nerve Palsy Secondary to Spontaneous Intracranial Hypotension

Clinical Correspondence Section Editors: Robert Avery, DO Karl C. Golnik, MD Caroline Froment, MD, PhD An-Guor Wang, MD Painful Oculomotor Nerve Palsy Secondary to Spontaneous Intracranial Hypotension Duncan Lyons, MBBS, Alexandra Lyons, MBBS, Paul Heyworth, MBBS, Fraser Imrie, FRANZCO T his case report demonstrates only the second published case of painful oculomotor nerve palsy secondary to spontaneous intracranial hypotension (SIH) and its subsequent management. A 48-year-old man presented to a rural emergency department (ED) with a 3-day history of gradual onset headache, left periorbital pain, nausea, vomiting, and bilateral neck pain. The headache was dull, continuous, postural, worsened throughout the day, and relieved when lying down. After normal computed tomography (CT), the patient was discharged with an idiopathic headache. The patient presented again to the same ED 2 days later with ongoing symptoms and diplopia, where he was diagnosed with a migraine and again discharged. The following day, he presented to his general practitioner again with new left ptosis in addition to his ongoing symptoms. He did not have vertigo, hearing disturbance, rhinorrhea, or any trauma. Examination revealed a left oculomotor nerve palsy, ocular pain distributed within the ophthalmic division (V1) of trigeminal nerve, with left ptosis, limited adduction, depression and elevation, and binocular diplopia worse on right lateral gaze. The pupils were spared. There was no papilledema or raised intraocular pressure. Neurological and systemic examination was otherwise normal. ED performed a MRI scan of his brain and spine, which showed features of intracranial hypotension, including bilateral subdural hygromas (Fig. 1), pachymeningeal enhancement, drooping of the corpus collosum, and extensive extradural spinal fluid collections. A cerebrospinal fluid (CSF) leak site was not identified. Because of the positive MRI signs, a lumbar puncture (LP) was not performed. He was diagnosed with headaches and painful oculomotor nerve palsy secondary to SIH and transferred for admission to a tertiary hospital. He was conservatively treated with bed rest, intravenous fluids, and caffeine tablets with limited improvement. A lumbar epidural blood patch (EBP) using 20 mL of autologous blood was successfully used, with headache improvement, but ongoing diplopia. A progress CT brain showed stable bilateral hygroma/chronic subdural hematomas. A repeat lumbar EBP was administered 6 days after initial treatment. Repeat ophthalmology examination revealed improving left oculomotor nerve palsy, and on discharge 2 days later, the patient’s headache and painful oculomotor nerve palsy had resolved. Repeat CT brain 3 weeks after discharge demonstrated resolution of the bilateral subdural hygromas (Fig. 2). SIH is characterized by an orthostatic headache that is relieved on lying down. The headache is often sudden onset coinciding with the time of CSF leak; however, similarly to our case, there have been rarer reports of gradual onset headaches (1). SIH results from a CSF leak in the absence of a history of trauma, LP, or surgery (1). Spontaneous leaks can occur from degenerative spinal disease with osteophytes Department of Ophthalmology, Gold Coast Health (DL, PH, FI), Gold Coast, Australia; and Department of Neurosurgery, Princess Alexandra Hospital (AL), Brisbane, Australia. The authors report no conflicts of interest. Address correspondence to Duncan Lyons, MBBS, Department of Ophthalmology, Gold Coast University Hospital, Gold Coast, QLD 4215, Australia; E-mail: [e-mail] e396 FIG. 1. T2 axial fat-saturated MRI of the vertex demonstrates bilateral CSF attenuating subdural collections. Lyons et al: J Neuro-Ophthalmol 2022; 42: e396-e397 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Clinical Correspondence FIG. 2. Axial noncontrast CT head demonstrates resolution of bilateral subdural hygromas at the vertex previously seen in Figure 1. and bony spurs catching the dura and causing a small tear (particularly along the dura of exiting nerve roots), spinal meningeal diverticula rupture, spinal arachnoid cyst rupture, and perineural cyst (1). The incidence of ophthalmoplegia associated with SIH ranges from 30% to 35%, with abducens nerve being the most common cranial nerve affected (83%) (2). The abducens nerve is most affected because of its long course where it travels from the pontine cistern, enters the space between the 2 layers of dura along the clivus, and is then anchored as it passes through the Dorello canal to enter the cavernous sinus, hence it is highly susceptible to compression in the Dorello canal from cerebral herniation (2). The pathophysiology of oculomotor nerve involvement is unclear, although it has been postulated to arise from being stretched because of downward displacement of intracranial structures (3). Branches of the trigeminal nerve run in the epineurium of the oculomotor nerve and irritation from stretch may explain the painful component associated with intracranial hypotension (4). Aneurysms causing external compression and ischemic vascular causes (e.g., diabetes and hypertension) can also produce painful oculomotor nerve palsies (1). There is only 1 other documented case of painful oculomotor nerve palsy (pupil involving) in the setting of SIH; however, their case differs in initial presentation because their patient presented with sudden onset severe headaches (4). Lyons et al: J Neuro-Ophthalmol 2022; 42: e396-e397 A thorough literature review revealed only 5 other cases of nonpainful oculomotor palsy (4 pupil sparing and 1 pupil involved) in the setting of SIH (2–5). This phenomenon was first reported in 1998 by Ferrente et al, (5) who noted 4 cases of abducens nerve palsy secondary to SIH, with one case additionally presenting with an oculomotor nerve palsy. All 5 cases had complete resolution of the oculomotor palsy and headache with either an EBP or conservative management, with the exception of the painful oculomotor palsy case, which had a 95% improvement on discharge (5). By contrast, our patient had complete resolution of symptoms. Clinical features that support a diagnosis of SIH include an orthostatic headache, CSF pressure under 6 cm of water on LP, and improvement after an EBP (1). MRI findings can include meningeal enhancement, venous engorgement, flattening of the pons, inferior displacement of the corpus callosum, cerebellar tonsil herniation, pituitary enlargement, subdural hygromas, and spinal subdural collections. Conservative management for SIH includes bed rest, increased caffeine consumption, and adequate hydration (1). If this fails to improve symptoms, an EBP can be used, and it works to increase the pressure of the potential space surrounding the spinal cord, stopping the flow of CSF, even if the specific location of the leak is not known (1). This case highlights that painful oculomotor palsy in the setting of orthostatic headaches is a very rare presentation, but it should raise high clinical suspicion for underlying SIH and be further investigated. Even if the location of CSF leak is unknown, an EBP is an effective treatment. STATEMENT OF AUTHORSHIP Category 1: a. Conception and design: D. Lyons, A. Lyons, P. Heyworth, and F. Imrie; b. Acquisition of data: D. Lyons, A. Lyons, P. Heyworth, and F. Imrie; c. Analysis and interpretation of data: D. Lyons, A. Lyons, P. Heyworth, and F. Imrie. Category 2: a. Drafting the manuscript: D. Lyons, A. Lyons, P. Heyworth, and F. Imrie; b. Revising it for intellectual content: D. Lyons, A. Lyons, P. Heyworth, and F. Imrie. Category 3: a. Final approval of the completed manuscript: D. Lyons, A. Lyons, P. Heyworth, and F. Imrie. REFERENCES 1. Greenberg MS. Handbook of Neurosurgery, 8th edition. New York, NY: Thieme, 2016. 2. Zada G, Solomon T, Giannotta S. A review of ocular manifestations in intracranial hypotension. Neurosurg Focus. 2007;23:E8. 3. Russo A, Tessitore A, Cirillo M, Giordano A, De Micco R, Bussone G, Tedeschi G. A transient third cranial nerve palsy as presenting sign of spontaneous intracranial hypotension. J Headache Pain. 2011;12:493–496. 4. Dandurand C, Haw C. Oculomotor palsy in spontaneous intracranial hypotension: case report and review of the literature. Can J Neurol Sci. 2016;43:747–749. 5. Ferrante E, Savino A, Marazzi R, Donato M, Riva M. Transient oculomotor cranial nerves palsy in spontaneous intracranial hypotension. J Neurosurg Sci. 1998;42:177–179. e397 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited.