Clinical and neuroimaging features of a familial pathogenic ACTA2 variant as a model of a vascular neurocristopathy.

The clinical and neuroimaging findings of a family with a variant ACTA2 gene (c351C > G), presenting with smooth muscle dysfunction in structures of neural crest derivation, are discussed. The combination of aortic abnormalities, patent ductus arteriosus, congenital mydriasis and distinctive cerebrovascular and brain morphological abnormalities characterise this disorder. Two sisters, heterozygous for the variant, and their mother, a mosaic, are presented. Brain parenchymal changes are detailed for the first time in a non-Arg179His variant. Radiological features of the petrous canal and external carotid are highlighted. We explore the potential underlying biological and embryological mechanisms.

Urrets-Zavalia syndrome following cataract surgery in dogs: A case series.

Background: In human medicine, Urrets-Zavalia syndrome (UZS) is a well-recognized but uncommon postoperative complication characterized by a fixed dilated pupil, accompanied by iris atrophy and glaucoma. Although it was originally reported in 1963 after penetrating keratoplasty surgery for keratoconus, it has been associated with various ophthalmic procedures such as cataract surgery. The condition has not been previously published in the veterinary literature. Case Description: Three client-owned diabetic dogs that developed UZS´s triad after cataract surgery are described. Despite uneventful phacoemulsification in the six eyes, five developed moderate-to-severe postoperative ocular hypertension. Although intraocular pressure (IOP) spikes were initially controlled, fixed dilated pupils accompanied by iris atrophy and chronic ocular hypertension were seen in the five affected eyes. Aggressive medical and surgical management maintained vision in three of those eyes. In one eye, uncontrolled IOP led to blindness. Conclusion: This is the first published description of UZS in dogs, occurring after phacoemulsification. Although no exact, demonstrable causative element could be determined, we believe that should be considered a triggering condition for this syndrome, as it directly affects the ocular blood flow autoregulation and intrinsic uveal tissue integrity. Until the contrary is proved, diabetes mellitus might be considered as a risk factor for developing this syndrome after cataract surgery in dogs.

Iris stromal cell nuclei deform to more elongated shapes during pharmacologically-induced miosis and mydriasis.

Nuclear shape alteration in ocular tissues, which can be used as a metric for overall cell deformation, may also lead to changes in gene expression and protein synthesis that could affect the biomechanics of the tissue extracellular matrix. The biomechanics of iris tissue is of particular interest in the study of primary angle-closure glaucoma. As the first step towards understanding the mutual role of the biomechanics and deformation of the iris on the activity of its constituent stromal cells, we conducted an ex-vivo study in freshly excised porcine eyes. Iris deformation was achieved by activating the constituent smooth muscles of the iris. Pupillary responses were initiated by inducing miosis and mydriasis, and the irides were placed in a fixative, bisected, and sliced into thin sections in a nasal and temporal horizontal orientation. The tissue sections were stained with DAPI for nucleus, and z-stacks were acquired using confocal microscopy. Images were analyzed to determine the nuclear aspect ratio (NAR) using both three-dimensional (3D) reconstructions of the nuclear surfaces as well as projections of the same 3D reconstruction into flat two-dimensional (2D) shapes. We observed that regardless of the calculation method (i.e., one that employed 3D surface reconstructions versus one that employed 2D projected images) the NAR increased in both the miosis group and the mydriasis group. Three-dimensional quantifications showed that NAR increased from 2.52 ± 0.96 in control group to 2.80 ± 0.81 and 2.74 ± 0.94 in the mydriasis and miosis groups, respectively. Notwithstanding the relative convenience in calculating the NAR using the 2D projected images, the 3D reconstructions were found to generate more physiologically realistic values and, thus, can be used in the development of future computational models to study primary angle-closure glaucoma. Since the iris undergoes large deformations in response to ambient light, this study suggests that the iris stromal cells are subjected to a biomechanically active micro-environment during their in-vivo physiological function.

Persistent isolated mydriasis as an early sign of internal carotid artery dissection: Pourfour du petit syndrome.

BACKGROUND: The dissection of the internal carotid artery (ICA) is commonly associated with miosis in Bernard-Horner syndrome (BHS). The presence of mydriasis is exceptional but can occur in the context of Pourfour du Petit syndrome (PDPS), a rare entity opposite of BHS accompanied by eyelid retraction and hyperhidrosis and caused by hyperactivity of the sympathetic cervical chain. AIM: To report on a case of PDPS as the first manifestation of an ICA dissection. METHOD: A 54-year-old man presented with isolated left mydriasis with no other abnormalities in the examination. Six months later, he suffered an ischemic stroke in the left middle cerebral artery territory secondary to a left ICA dissection. RESULTS: The initial study with Intracranial computed tomographic angiography and brain magnetic resonance imaging ruled out compressive cause of the third cranial nerve or structural lesion in the midbrain. The absence of hypersensitivity to Pilocarpine discarded postganglionic parasympathetic involvement. CONCLUSIONS: In the presence of unilateral mydriasis and once common causes are ruled out an imaging examination of the supra-aortic trunks should be completed, since it could represent the first sign of carotid pathology in the context of PDPS.

Superior efficacy of HI-6 dimethanesulfonate over pralidoxime methylsulfate against Russian VX poisoning in cynomolgus monkeys (Macaca fascicularis).

Organophosphorus nerve agents still represent a serious risk to human health. In the French armed forces, the current emergency treatment against OP intoxications is a fully licensed wet-dry dual-chambered autoinjector (Ineurope ®), that contains pralidoxime methylsulfate (2-PAM) to reactivate inhibited acetylcholinesterase (AChE), atropine sulfate (AS) and avizafone chlorhydrate (AVZ). While this treatment is effective against several of the known nerve agents, it shows little efficacy against the Russian VX (VR), one of the most toxic compounds. HI-6 dimethanesulfonate (HI-6 DMS) is an oxime able to reactivate in vitro and in vivo VR-inhibited AChE. To confirm the superiority of HI-6 DMS towards 2-PAM prior to licensing, we compared the two 3-drug-combinations (HI-6 vs 2-PAM, 33 and 18 mg/kg respectively, equimolar doses; AS/AVZ 0.25/0.175 mg/kg respectively) in VR-poisoned cynomolgus macaques, the model required by the French drug regulatory agency. In parallel we performed HI-6 pharmacokinetics analysis using a one compartment model. A better efficacy of the HI-6 DMS combination was clearly observed: up to 5 LD50 of VR (i.m.), a single administration of the HI-6 DMS combination, shortly after the onset of clinical signs, prevented death of the four intoxicated animals. Conversely 2-PAM only prevented death in one out of three subjects exposed to the same amount of VR. As expected with V agents, reinhibition of blood AChE was observed but without any apparent impact on the clinical recovery of the animals. A single administration of the HI-6 DMS combination was still but partially effective at 15 LD50 of VR, allowing a 50% survival rate.

Uncovering the Forgotten Effect of Superior Cervical Ganglia on Pupil Diameter in Subarachnoid Hemorrhage: An Experimental Study.

AIM: To investigate the relationship between neuron density of the superior cervical sympathetic ganglia and pupil diameter in subarachnoid hemorrhage. MATERIAL AND METHODS: This study was conducted on 22 rabbits; 5 for the baseline control group, 5 for the SHAM group and 12 for the study group. Pupil diameters were measured via sunlight and ocular tomography on day 1 as the control values. Pupil diameters were re-measured after injecting 0.5 cc saline to the SHAM group, and autologous arterial blood into the cisterna magna of the study group. After 3 weeks, the brain, superior cervical sympathetic ganglia and ciliary ganglia were extracted with peripheral tissues bilaterally and examined histopathologically. Pupil diameters were compared with neuron densities of the sympathetic ganglia and ciliary ganglia which were examined using stereological methods. RESULTS: Baseline values were; normal pupil diameter 7.180±620 ?m and mean neuron density of the superior cervical sympathetic ganglia 6.321±510/mm3, degenerated neuron density of ciliary ganglia was 5±2/mm3 after histopathological examination in the control group. These values were measured as 6.850±578 ?m, 5.950±340/mm3 and 123±39/mm3 in the SHAM group and 9.910±840 ?m, 7.950±764/mm3 and 650±98/mm3 in the study group. A linear relationship was determined between neuron density of the superior cervical sympathetic ganglia and pupil diameters (p < 0.005). Degenerated ciliary ganglia neuron density had an inverse effect on pupil diameters in all groups (p < 0.0001). CONCLUSION: Highly degenerated neuron density of the ciliary ganglion is not responsible for pupil dilatation owing to parasympathetic pupilloconstrictor palsy, but high neuron density of the pupillodilatatory superior cervical sympathetic ganglia should be considered an important factor for pupil dilatation.

Two patients with the heterozygous R189H mutation in ACTA2 and Complex congenital heart defects expands the cardiac phenotype of multisystemic smooth muscle dysfunction syndrome.

De novo heterozygous mutations changing R179 to histidine, leucine, or cysteine in the ACTA2 gene are associated with Multisystemic Smooth Muscle Dysfunction Syndrome (MSMDS). Characteristic hallmarks of this condition, caused only by these specific ACTA2 mutations, are congenital mydriasis (mid-dilated, non-reactive pupils), a large persistent ductus arteriosus (PDA), aortic aneurysms evolving during childhood, and cerebrovascular anomalies. We describe two patients, a 3-day-old newborn and a 26-year-old woman, with this unique mutation in association with a huge PDA and an aorto-pulmonary window. In addition, one showed a coarctation of the aortic arch and the other a complete interruption of the aortic arch type A; thereby expanding the spectrum of cardiac congenital heart defect of this syndrome. Each patient displayed a huge PDA and an extra-cardiovascular phenotype consistent with MSMDS. These observations exemplify that a functional alpha 2 smooth muscle actin is necessary for proper cardiovascular organ development, and demonstrate that a very exceptional congenital heart defect (aortopulmonary window) can be caused by a mutation in a gene encoding a contractile protein of vascular smooth muscle cells. © 2017 Wiley Periodicals, Inc.

Changes in ocular biometry and anterior chamber parameters after pharmacologic mydriasis and peripheral iridotomy in primary angle closure suspects / Cambios en la biometría ocular y los parámetros de la cámara anterior tras midriasis farmacológica e iridotomía periférica en sospechas de cierre angular primario

Purpose: The aim of this study was to evaluate the effects of pharmacologic mydriasis and Peripheral Iridotomy (PI) on ocular biometry and anterior chamber parameters in primary angle closure suspects. Methods: In this prospective interventional case series, 21 primary angle closure suspects were enrolled. Intraocular pressure, refraction, ocular biometry (Lenstar, LS900), and anterior chamber parameters (Pentacam HR) were measured at four occasions: before PI (before and after mydriasis with phenylephrine) and two weeks after PI (before and after mydriasis). The study was conducted on both eyes and only one eye per patient, in random, was included in the analysis. Results: The mean age of the participants was 60±7 years and 17 (81%) were female. There were no significant differences in intraocular pressure, refraction, keratometry, biometric and anterior chamber parameters between groups, except for anterior chamber volume, which showed increments with PI and mydriasis. The corresponding values for anterior chamber volume were as follows: 88.2±13.7mm3 before PI, undilated; 106.3±18.8 before PI, dilated; 99.0±14.6 after PI, undilated, and 107.4±16.5 after PI, dilated (P<0.001). Conclusions: This study showed no change in the ocular biometric and anterior chamber parameters including iridocorneal angle after PI and/or pharmacologic mydriasis except for increments in anterior chamber volume. This factor has the potential to be used as a numerical proxy for iris position in evaluating and monitoring patients with primary angle closure suspects after PI (AU)

Objetivo: El objetivo de este estudio fue el de evaluar los efectos de la midriasis farmacológica y la iridotomía periférica (IP) en la biometría ocular y los parámetros de la cámara anterior en las sospechas de cierre angular primario. Métodos: En esta serie de casos intervencional prospectiva, se incluyó a 21 sospechas de cierre angular primario. Se realizaron las mediciones siguientes: presión intraocular, refracción, biometría ocular (Lenstar, LS900), y parámetros de la cámara anterior (Pentacam HR) en cuatro ocasiones, antes de la IP (antes y después de la midriasis con fenilefrina) y dos semanas después de la IP (antes y después de la midriasis). El estudio se realizó en ambos ojos, incluyéndose en el análisis un solo ojo por paciente de manera aleatoria. Resultados: La edad media de los participantes fue de 60±7 años, de los cuales 17 eran mujeres (81%). No se hallaron diferencias significativas en cuanto a presión intraocular, refracción, queratometría, parámetros biométricos y de la cámara anterior entre los grupos, exceptuando el volumen de la cámara anterior, que reflejó incrementos con la IP y la midriasis. Los valores correspondientes para el volumen de la cámara anterior fueron los siguientes: 88.2±13,7mm3antes de la IP, sin dilatación; 106.3±18,8 antes de la IP, con dilatación; 99.0±14,6 tras la IP, sin dilatación, y 107.4±16,5 tras la IP, con dilatación (P<0,001). Conclusiones: El presente estudio no reflejó cambios en los parámetros biométricos oculares y de la cámara anterior, incluyendo el ángulo iridocorneal tras la IP y/o midriasis farmacológica, exceptuando los incrementos del volumen de la cámara anterior. Este factor tiene el potencial de ser utilizado como indicador numérico de la posición del iris al evaluar y supervisar a los pacientes con sospechas de cierre angular primario tras IP (AU)

An experimental study of the neurophysical mechanisms of photophobia induced by subarachnoid hemorrhage.

BACKGROUND: Photophobia is defined as a painful psychosomatic discomfort triggered by intense light flow through the pupils to the brain, but the exact mechanism through which photophobia is induced by subarachnoid hemorrhage (SAH) is not well understood. In this study, we aimed to investigate whether there was any relationship between the mydriasis induced by the degeneration of the ciliary ganglion (CG) and photophobia in instances of SAH. MATERIALS AND METHODS: Five of a total of 25 rabbits were used as the intact control group; five were used in the sham-operated control group; and the remaining 15 were used as the SAH group, which was created by injecting autologous blood into their cisterna magna. All animals were examined daily for 20days to evaluate their level of photophobia, after which their brains, CGs and superior cervical ganglia (SCGs) were extracted bilaterally. The densities of normal and degenerated neurons in these ganglia were examined by stereological methods. RESULTS: In SAH animals with a high photophobia score, the mean pupil diameter and density of degenerated neurons density in the CG were greater than in cases with a low photophobia score (p<0.05). Further analysis revealed that the increase in the density of degenerated neurons in the CG following SAH resulted in the paralysis of the parasympathetic pathway of the pupillary muscles and mydriasis, which facilitates the excessive transfer of light to the brain and photophobia. CONCLUSION: Our findings indicate that SAH results in a high density of degenerated neurons in the CG, which induces mydriasis and is an important factor in the onset of photophobia. This phenomenon is likely due to more light energy being transferred through mydriatic pupils to the brain, resulting in vasospasm of the supplying arteries.

Pupila tónica como manifestación inicial de un síndrome de Sjögren / Tonic pupil as an initial manifestation of Sjögren's syndrome

No disponible

Midriasis benigna episódica. Experiencia en una consulta monográfica de neuro-oftalmología de un hospital terciario / Benign episodic mydriasis. Experience in a specialist neuro-ophthalmology clinic of a tertiary hospital

Introducción: Las anisocorias son un motivo de consulta relativamente frecuente en unidades de neuro-oftalmología (UNO). Suponen un reto diagnóstico por la variedad de procesos que pueden ocasionarla. En ausencia de síntomas acompañantes, suelen estar ocasionadas por procesos benignos. La midriasis benigna episódica (MBE) es una causa aislada de asimetría pupilar intermitente, de fisiopatología no esclarecida y predominio en mujeres jóvenes migrañosas. Sujetos, material y métodos: Describimos las características epidemiológicas y clínicas de los pacientes con MBE valorados en una UNO de un hospital terciario. Resultados: Un total de 7 pacientes fueron diagnosticadas de MBE. Todas eran mujeres, con edad media de 33 ± 10 años. Los motivos de consulta fueron asimetría pupilar (n = 5) y visión borrosa (n = 2) de presentación fundamentalmente unilateral (n = 6). La duración fue variable, desde minutos hasta 48 h. Cuatro pacientes (57%) presentaban como antecedente migraña sin aura. En estas, los episodios eran recidivantes (75%), de minutos de duración (75%) y asociaban visión borrosa (50%). Los estudios de neuroimagen (resonancia magnética cerebral) fueron normales. Discusión: La midriasis benigna episódica se presenta predominantemente en mujeres jóvenes. Se asocia al antecedente de migraña y hace plantear si se trata de un síntoma acompañante de la migraña, un aura migrañosa o de migraña oftalmopléjica. De predominio unilateral, puede sin embargo existir alternancia del ojo afectado o ser bilateral de forma simultánea, lo que nos hace cuestionarnos la idoneidad del término. En ausencia de síntomas acompañantes y en episodios de corta duración, no consideramos necesaria la realización de pruebas de imagen

Introduction: Anisocorias are a relatively frequent reason for consultation in neuro-ophthalmology units. They remain a diagnostic challenge for specialists as they may be due to several etiological factors. In the absence of other accompanying symptoms, anisocorias are usually due to benign processes. Benign episodic mydriasis (BEM) is an isolated cause of intermittent pupil asymmetry, in which the pathophysiology is still not fully understood, and is predominant in young women with migraine. Subjects, material and methods: We describe the epidemiological and clinical characteristics of patients with BEM, assessed in a neuro-ophthalmology unit in a tertiary hospital. Results: A total of 7 patients were diagnosed with BEM, all of them females, with a mean age of 33 ± 10 yrs. The patients presented with pupil asymmetry (n = 5) and blurred vision (n = 2), and 6 of the 7 patients had unilateral involvement. The duration of impairment varied from a few minutes to 48 hrs. Four patients (57%) had a clinical history of migraine without aura. The episodes in these 4 patients were recurrent (75%), often lasted for a few minutes (75%), and had associated blurred vision (50%). The neuroimaging studies were normal. Discussion: BEM appears predominantly in young women. It is frequently related to a previous history of migraine, and the specialist must consider if it is a concomitant symptom of common migraine, migraine with aura, or ophthalmoplegic migraine. Although BEM has unilateral predominance, there may be alternation of the affected eye or even bilateral impairment during the same episode, which makes us question the adequacy of the term to describe the process. Imaging tests are not recommended in the absence of other accompanying symptoms, or in short-term episodes

The effects of taurine on vigabatrin, high light intensity and mydriasis induced retinal toxicity in the pigmented rat.

The overall purpose of this study was to establish a model that may be used for examining the effect of Vigabatrin-induced retinal toxicity in pigmented rats, and subsequently examine the possible effects of taurine on the retinal toxicity. In the first part of the study, pigmented Long Evans rats were subjected to combinations of induced mydriasis, low/high light intensities (40/2000 lx) and oral administration of near-MTD (Maximum Tolerated Dose) doses (200 mg/kg/day) of Vigabatrin for up to 6 weeks. The combination of mydriasis and high light intensity applied to Long Evans rats resulted in retinal damage that was increased by the administration of Vigabatrin. In the second part of the study Long Evans rats were subjected to combinations of induced mydriasis and high/low light intensity (40/2000 lx) while being orally administered low (30 mg/kg/day) or high (200 mg/kg/day) doses of Vigabatrin for up to 6 weeks. In addition, selected groups of animals were administered taurine via the drinking water (20 mg/ml), resulting in systemic taurine concentrations of approximately threefold the endogenous concentration. The combined results of the studies demonstrate that retinal damage can be induced in pigmented animals when combining mydriasis and high light intensity. Retinal damage was functionally evaluated by electroretinography (ERG), then confirmed by histopathology. While depending on mydriasis and high light intensity, administration of Vigabatrin increased the retinal toxicity and resulted in the formation of rosette-like structures in the retina in a dose-related manner. Administration of taurine did not alleviate the Vigabatrin-induced retinal toxicity, as demonstrated either functionally by ERG or morphologically, although systemic concentrations of 3-fold the endogenous levels were reached, and it was thus not possible to demonstrate a protective effect of taurine in these pigmented animals.

Quantitative analysis of iris changes after physiologic and pharmacologic mydriasis in a rural Chinese population.

PURPOSE: To estimate and compare the change in iris cross-sectional area (IA) and iris volume (IV) following physiologic and pharmacologic pupil dilation in primary angle closure suspects (PACS) and normal subjects. METHODS: Anterior segment-optical coherence tomography (AS-OCT) measurements in light, dark, and following pharmacologic dilation were obtained on 186 PACS and 224 normal subjects examined during the 5-year follow-up of the Handan Eye Study. Iris cross-sectional area, IV, and other biometric parameters calculated using the Zhongshan angle assessment program in the right eyes of all subjects were analyzed. RESULTS: The mean IA and IV decreased in dark compared with light and after pharmacologic dilation in both PACS and normal eyes. This change was statistically significant in normal eyes: light versus pharmacologic dilation for IA (P = 0.038) and for IV, both light versus dark (P = 0.031) and light versus pharmacologic dilation (P = 0.012). A longer axial length (P = 0.028) and a greater change in pupil diameter (PD) (P < 0.001) were associated with a larger decrease of IA for the light to dark comparison. A diagnosis of normal eyes (P = 0.011), larger PD in dark (P = 0.001), and a larger change in PD (P = 0.001) were associated with a larger decrease of IV from light to dark. CONCLUSIONS: The differences in iris behavior between PACS and normal rural Chinese subjects following physiologic or pharmacologic pupillary dilation may help provide insights into the pathogenesis of angle closure.

Síndrome selar y paraselar: una nueva mononeuropatía múltiple bilateral en perros y gatos / Sellar and parasellar syndrome: a novel bilateral multiple mononeuropathy in dogs and cats

La región selar y paraselar (SPS) contiene formaciones óseas, vasculares, nervios somáticos y autónomos, la hipófisis y las estructuras meníngeas relacionadas que la convierte en asiento de diversas patologías neurológicas, oftalmológicas o endocrinológicas. El objetivo de este trabajo es describir la anatomía de la región SPS y comunicar un cuadro clínico observado en un perro y en 2 gatos consistente en una mononeuropatía múltiple que involucra diversos NC en su recorrido en relación a esta región que, por sus características, constituye un síndrome particular. En nuestro conocimiento esta es la primera descripción de un síndrome que afecte a perros y gatos y que pueda comprometer simultáneamente uno o más de los NC II, III, IV, los 3 nervios que forman el V (oftálmico, maxilar y mandibular) y VI, a la glándula hipófisis y sus cubiertas meníngeas, y al tronco encefálico (diencéfalo) (AU)

The sellar and parasellar region (SPS) contains bone structures, vascular structures, somatic and autonomous nerves, the pituitary gland and meningeal structures related that predisposes to various neurological, ophthalmologic or endocrine diseases The aim of this work is to describe the anatomy of the SPS region and communicate a clinical picture observed in a dog and 2 cats consisting of a multiple mononeuropathy involving various cranial nerves on their way in relation to this region and, by its nature, is particularly syndrome. To our knowledge this is the first description of a syndrome affecting dogs and cats and can simultaneously engage one or more of the II, III, IV, V (ophthalmic, maxillary and mandibular nerves) and VI cranial nerves, the pituitary gland and its meningeal coverings, and the brain and brain stem (AU)

Congenital mydriasis associated with megacystis microcolon intestinal hypoperistalsis syndrome.

We report a case of congenital mydriasis in a neonate with megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS). Pilocarpine testing and gastrointestinal pathology in our patient suggest that the mydriasis is due to an underlying smooth muscle myopathy of the iris sphincter muscle. These findings may have important implications regarding the pathogenesis of MMIHS.

Eye features in three Danish patients with multisystemic smooth muscle dysfunction syndrome.

BACKGROUND: A de novo mutation of the ACTA2 gene encoding the smooth muscle cell α-actin has been established in patients with multisystemic smooth muscle dysfunction syndrome associated with patent ductus arteriosus and mydriasis present at birth. OBJECTIVE: To describe the structural ocular findings in three Danish children with this new syndrome and evaluate the possible functional consequences for visual development of the poorer imaging condition. RESULTS: Unresponsive mydriatic pupils with scalloping wisps of persistent pupillary membrane from the iris collarette were an early indicator of this rare genetic disorder in all three cases. Tortuousity of retinal arterioles was the main posterior pole finding, apparent during the first year of life and with a tendency to increase with age. In one case, it progressed to an aneurysmal-like state with breakdown of the blood-retinal barrier. CONCLUSIONS: Congenital mydriasis is an extremely rare pupil anomaly and is the feature for the early diagnosis of this new syndrome. The ophthalmologist should act in close collaboration with other specialists owing to the risk of aortic and cerebrovascular diseases and other complications associated with this disorder.

Pupil-sparing oculomotor nerve palsy caused by upward compression of a large posterior communicating artery aneurysm. Case report.

A 69-year-old woman without diabetes or hypertension presented with a large posterior communicating artery aneurysm projecting beneath the oculomotor nerve manifesting as a 2-week history of progressive diplopia. Neurological examination revealed external ophthalmoplegia and blepharoptosis without pupil involvement. Neuroimaging showed a large aneurysm in the left internal carotid artery projecting postero-inferiorly. Craniotomy and neck clipping of the aneurysm revealed the origin at the junction of the internal carotid artery and posterior communicating artery, and elevation of the oculomotor nerve. Pupil-sparing oculomotor nerve palsy is often assumed to be caused by ischemic injury such as hypertension and diabetes mellitus. Sometimes compressive lesion can cause pupil-sparing oculomotor nerve palsy with a short interval from the onset of symptoms to diagnosis. Despite the 2-week interval from the onset of symptoms, this patient presented with pupil-sparing oculomotor nerve palsy caused by compressive lesion. Involvement or sparing of the pupil is often considered to be the most important criterion in the diagnosis of isolated oculomotor nerve palsy. This unique case demonstrated that unusual compressive lesions must be taken into consideration in the diagnosis of pupil-sparing oculomotor nerve palsy.