About MEAJO | Editorial board | Search | Ahead of print | Current Issue | Archives | Instructions to authors | Online submission | Subscribe | Advertise | Contact | Login 
Middle East African Journal of Ophthalmology Middle East African Journal of Ophthalmology
Users Online: 293   Home Print this page Email this page Small font sizeDefault font sizeIncrease font size


 
  Table of Contents 
CASE REPORT
Year : 2012  |  Volume : 19  |  Issue : 2  |  Page : 237-239  

Pupil-sparing complete third nerve palsy from cryptogenic midbrain stroke in an otherwise-healthy young adult with patent foramen ovale


Division of Pediatric Ophthalmology and Strabismus, King Khaled Eye Specialist Hospital, Riyadh, Kingom of Saudi Arabia

Date of Web Publication21-Apr-2012

Correspondence Address:
Arif O Khan
Division of Pediatric Ophthalmology & Strabismus, King Khaled Eye Specialist Hospital, PO Box 7191, Riyadh 11462
Kingom of Saudi Arabia
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0974-9233.95260

Rights and Permissions
   Abstract 

Although pupil-sparing in acute unilateral complete third nerve palsy is often a sign of ischemic nerve injury, it is not specific for injury outside of the midbrain. This report documents acute pupil-sparing complete third nerve palsy in an otherwise healthy young adult with patent foramen ovale and associated atrial dilatation who suffered cryptogenic focal midbrain stroke, presumably from a paradoxical embolism. The patent foramen ovale was surgically closed. Over the next several months neurological recovery was complete except for diplopia and relatively comitant hypotropia, which responded well to conventional strabismus surgery.

Keywords: Foramen Ovale, Midbrain Stroke, Pupil-Sparing, Third Nerve Palsy


How to cite this article:
Khan AO. Pupil-sparing complete third nerve palsy from cryptogenic midbrain stroke in an otherwise-healthy young adult with patent foramen ovale. Middle East Afr J Ophthalmol 2012;19:237-9

How to cite this URL:
Khan AO. Pupil-sparing complete third nerve palsy from cryptogenic midbrain stroke in an otherwise-healthy young adult with patent foramen ovale. Middle East Afr J Ophthalmol [serial online] 2012 [cited 2019 Dec 14];19:237-9. Available from: http://www.meajo.org/text.asp?2012/19/2/237/95260


   Introduction Top


Although pupil-sparing in acute unilateral complete third nerve palsy is often a sign of ischemic nerve injury, it is not specific for injury outside of the midbrain. [1],[2],[3] This report documents acute pupil-sparing complete third nerve palsy in an otherwise-healthy young adult with patent foramen ovale and associated atrial dilatation who suffered cryptogenic focal midbrain stroke, presumably from a paradoxical embolism.


   Case Report Top


A 23-year-old otherwise healthy female with a 2-day history of diplopia and right ptosis after awakening had right complete pupil-sparing third nerve palsy (complete ptosis, moderate hypotropia, large exotropia and no supraduction/infraduction/adduction). Ocular examination was otherwise unremarkable in both eyes. Directed questioning and physical exam also revealed left dysmetria of the upper and lower extremity, left partial upper motor facial nerve weakness and impaired touch sensation on the right anterior 2/3 of the tongue. Neurology and rheumatology consultations confirmed these as the only significant physical examination findings.

The patient underwent extensive medical questioning and investigation. A review of symptoms and history included questioning regarding any recent illnesses, skin rashes, ulcers or sores, insect bites, pains, respiratory symptoms, gastrointestinal symptoms, urinary symptoms, neurological symptoms, trauma, medication history, prior hospitalizations, intravenous needle use, trips abroad and illnesses in family members. The patient had suffered from occasional oral ulcers and minor pain in the left knee over the last few years. Laboratory studies included complete blood count, erythrocyte sedimentation rate, platelet count, prothrombin time, activated prothrombin time, bleeding time, lipid profile, plasma homocystine, fasting blood sugar, anticardiolipin (antiphospholipid) antibody, lipoprotein A, plasma fibrinogen, factor V Leiden, antithrombin III, protein S, protein C, antinuclear antibody, purified protein derivative standard testing, Treponema pallidum hemagglutination assay, Venereal Disease Research Laboratory assay, sickle cell testing, prothrombin (factor II) analysis for gene mutation at G20210A and acetylcholine antibody receptor testing. These investigations were significant only for sickle cell trait. Radiological studies included chest X-ray, trans-esophageal echocardiography, brain magnetic resonance imaging (MRI), carotid Doppler ultrasound and cerebral angiography. MRI was significant for a focal T2-weighted hyperintense focal midbrain lesion adjacent to the aqueduct of Sylvius and consistent with infarction [Figure 1]. Echochardiography revealed aneurismal atrial septum with relatively large (0.7 cm) patent foramen ovale. Cardiology and neurology consultants agreed that the patent foramen ovale in this setting led to paradoxical embolism and cryptogenic midbrain stroke. The foramen ovale was thus closed surgically via catheterization.
Figure 1: In this T2-weighted magnetic resonance image with contrast, an almond-shaped hyperintense lesion can be seen in the right midbrain adjacent to the aqueduct of Sylvius. The eyes are in right gaze

Click here to view


Over the next few months, all signs and symptoms resolved except for a residual right hypotropia and constant vertical diplopia in all positions of gaze. Repeated MRI scanning showed resolution of the prior lesion with no other abnormalities. Two years after the event, ophthalmic examination was significant for a stable relatively comitant right hypotropia of 25 prism diopters that was slightly greater in upgaze with minimal right supraduction limitation. Forced generation and forced duction testing of the right eye were normal. Following informed consent, the patient underwent right superior rectus muscle resection of 6 mm and right inferior rectus muscle recession of 6 mm via a fornix technique. Postoperatively, the patient was diplopia-free with a slight chin-up position. There was a minimal right hypotropia in the forced primary position, which increased to 10-15 prism diopters in upgaze. She has remained stable and satisfied one year following strabismus surgery.


   Discussion Top


Generally, sparing of the pupil in acute unilateral complete third nerve palsy suggests ischemic extraaxial (nerve) injury. [1] However, this "rule of the pupil" is less applicable to younger patients without any ischemic risk factors. [1],[2] Pupil-sparing in unilateral complete third nerve palsy can occur secondary to focal midbrain injuries that affect third nerve fascicles responsible for extraocular and levator muscles without affecting topographically separated fascicules that carry pupillary fibers. [1] Directed questioning and physical exam often reveal accompanying neurological signs and symptoms that were not initially volunteered by an affected patient, though very rarely a complete midbrain pupil-sparing complete third nerve palsy can be truly isolated. [3]

Third nerve fascicules maintain their topographical arrangement through and around the red nucleus before exiting the midbrain adjacent to the cerebral peduncle as the third nerve. [4] Several named syndromes describe the possible neurological associations of midbrain third nerve fascicular injury. [5] Fascicular injury in the area of the red nucleus can cause third nerve palsy with contralateral hemitremor via damage to cerebral afferents to the thalamus (Benedikt syndrome). Fascicular injury in the area of the cerebral peduncle can cause third nerve palsy with contralateral hemiparesis including the lower face and tongue ( Weber syndrome More Details). Other named syndromes include Nothnagel syndrome (midbrain third nerve palsy with ipsilateral cerebellar ataxia from injury to the superior cerebellar peduncle) and Claude syndrome (midbrain third nerve palsy plus contralateral ataxia, asynergy and dysdiadochokinesis due to involvement of the red nucleus and superior cerebellar peduncle). In practice, neurological signs and symptoms that accompany midbrain third nerve injury do not usually cleanly compartmentalize into an eponymous syndrome. [6]

Midbrain third nerve injury is typically ischemic in origin and rarely embolic. [6] Although patent foramen ovale is a common congenital defect that by itself is often of no consequence, it confers a risk for stroke via paradoxical embolism when associated with atrial dilatation. [6],[7] A patent foramen ovale can allow particles in the circulation that are normally filtered by small capillaries in the lungs to be transmitted directly from the right to the left atrium and thus gain access to the cerebral small vessel circulation, which is particularly susceptible to embolic phenomena.

In the current patient, all signs of midbrain stroke resolved with time except for a relatively comitant hypertropia with associated vertical diplopia. The deviation responded well to conventional strabismus surgery. Both pre- and postoperatively, there was a slight right supraduction defect. In the setting of grossly normal forced duction and forced generation testing, the preoperative incomitance suggested a minimal residual superior rectus weakness from the midbrain insult.

 
   References Top

1.Nadeau SE, Trobe JD. Pupil sparing in oculomotor palsy: A brief review. Ann Neurol 1983;13:143-8.  Back to cited text no. 1
    
2.Trobe JD. Third nerve palsy and the pupil. Footnotes to the rule. Arch Ophthalmol 1988;106:601-2.  Back to cited text no. 2
    
3.Breen LA, Hopf HC, Farris BK, Gutmann L. Pupil-sparing oculomotor nerve palsy due to midbrain infarction. Arch Neurol 1991;48:105-6.  Back to cited text no. 3
    
4.Saeki N, Murai H, Mine S, Yamaura A. Fascicular arrangement within the oculomotor nerve MRI analysis of a midbrain infarct. J Clin Neurosci 2000;7:268-70.   Back to cited text no. 4
    
5.Disorders affecting the fascicles of the oculomotor nerve. In: Leigh RJ, Zee DS, editors. The Neurology of Eye Movements. 4 th ed. New York, NY: Oxford University Press; 2006. p. 430.  Back to cited text no. 5
    
6.Kim JS, Kim J. Pure midbrain infarction: Clinical, radiologic, and pathophysiologic findings. Neurology 2005;64:1227-32.  Back to cited text no. 6
    
7.Thaler DE, Saver JL. Cryptogenic stroke and patent foramen ovale. Curr Opin Cardiol 2008;23:537-44.  Back to cited text no. 7
    


    Figures

  [Figure 1]


This article has been cited by
1 Managing the patient with oculomotor nerve palsy
Karthikeyan A. Sadagopan,Barry N. Wasserman
Current Opinion in Ophthalmology. 2013; 24(5): 438
[Pubmed] | [DOI]



 

Top
  
 
  Search
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

 
  In this article
    Abstract
   Introduction
   Case Report
   Discussion
    References
    Article Figures

 Article Access Statistics
    Viewed2521    
    Printed106    
    Emailed0    
    PDF Downloaded110    
    Comments [Add]    
    Cited by others 1    

Recommend this journal