Unilateral and Asymmetric Optic Disk Swelling with Intracranial Abnormalities

Sedwick, Lyn A.; Burde, Ronald M.

doi:10.1016/s0002-9394(14)77912-7

Cited by 37 publications

(12 citation statements)

References 4 publications

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“…There is no known explanation for the occurrence of intracranial hypertension without papilledema. However, asymmetric papilledema (where one nerve is severely swollen, and the other one is normal or minimally swollen) has been reported 33‐35 . A change in brain compliance, 33 congenital variation of the canalicular optic nerve, 34 or intermittent rises in pressure 35 are mechanisms proposed to explain why one disc may not swell.…”

Section: Discussionmentioning

confidence: 99%

A Comparison of Idiopathic Intracranial Hypertension With and Without Papilledema

et al. 2009

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Objective To compare clinical features, visual characteristics, and treatment of idiopathic intracranial hypertension patients with and without papilledema. Background Idiopathic intracranial hypertension does not often occur without papilledema. This study estimates the prevalence and compares the clinical characteristics of idiopathic intracranial hypertension patients with and without papilledema. Methods We performed a cross-sectional analysis of all idiopathic intracranial hypertension patients diagnosed at the University of Utah Neuro-Ophthalmology Unit between 1990 and 2003. Patient records were reviewed for presence of papilledema and other signs, symptoms, and treatment characteristics. Each patient without papilledema was matched to the patient with papilledema who was closest to his/her age and sex. McNemar’s and Wilcoxon-signed rank sum tests were used to compare characteristics between matched pairs. Results Among all patients (n = 353), the prevalence of those without papilledema was 5.7% (n = 20). Patients without papilledema reported photopsias (20%), and were found to have spontaneous venous pulsations (75%) and non-physiologic visual field constriction (20%) more often than did those with papilledema. Mean opening pressure, although above normal, was lower in patients without papilledema (mean = 309 mm cerebrospinal fluid) compared with those with papilledema (mean = 373 mm cerebrospinal fluid, P = .031). Idiopathic intracranial hypertension patients without papilledema had more frequent diagnostic lumbar punctures than did patients with papilledema. Visual acuities and treatment were similar between groups. Conclusions The clinical presentation of idiopathic intracranial hypertension without papilledema is only somewhat different from that of idiopathic intracranial hypertension with papilledema. The lower opening pressure in patients without papilledema may explain variations in symptoms and signs between the 2 groups. When there are visual field changes in idiopathic intracranial hypertension without papilledema, non-physiologic visual loss should be considered.

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Section: Discussionmentioning

confidence: 99%

A Comparison of Idiopathic Intracranial Hypertension With and Without Papilledema

et al. 2009

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“…24 25 We suggest that further studies should aim to demonstrate possible changes of the arachnoid trabeculae and septa in pathological conditions such as asymmetric and unilateral papilloedema and optic neuritis. [26][27][28][29][30][31] …”

Section: Discussionmentioning

confidence: 99%

Architecture of arachnoid trabeculae, pillars, and septa in the subarachnoid space of the human optic nerve: anatomy and clinical considerations

Killer

Laeng²,

Flammer³

et al. 2003

British Journal of Ophthalmology

297

214

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Aims: To describe the anatomy and the arrangement of the arachnoid trabeculae, pillars, and septa in the subarachnoid space of the human optic nerve and to consider their possible clinical relevance for cerebrospinal fluid dynamics and fluid pressure in the subarachnoid space of the human optic nerve. Methods: Postmortem study with a total of 12 optic nerves harvested from nine subjects without ocular disease. All optic nerves used in this study were obtained no later than 7 hours after death, following qualified consent for necropsy. The study was performed with transmission (TEM) and scanning electron microscopy (SEM). Results: The subarachnoid space of the human optic nerve contains a variety of trabeculae, septa, and stout pillars that are arranged between the arachnoid and the pia layers of the meninges of the nerve. They display a considerable numeric and structural variability depending on their location within the different portions of the optic nerve. In the bulbar segment (ampulla), adjacent to the globe, a dense and highly ramified meshwork of delicate trabeculae is arranged in a reticular fashion. Between the arachnoid trabeculae, interconnecting velum-like processes are observed. In the mid-orbital segment of the orbital portion, the subarachnoid space is subdivided, and can appear even loosely chambered by broad trabeculae and velum-like septa at some locations. In the intracanalicular segment additionally, few stout pillars and single round trabeculae are observed. Conclusion: The subarachnoid space of the human optic nerve is not a homogeneous and anatomically empty chamber filled with cerebrospinal fluid, but it contains a complex system of arachnoid trabeculae and septa that divide the subarachnoid space. The trabeculae, septa, and pillars, as well as their arrangement described in this study, may have a role in the cerebrospinal fluid dynamics between the subarachnoid space of the optic nerve and the chiasmal cistern and may contribute to the understanding of the pathophysiology of asymmetric and unilateral papilloedema. All the structures described are of such delicate character that they can not even be visualised with high resolution magnetic resonance imaging (MRI).T he optic nerve is a white matter tract of the central nervous system that extents through the optic canal into the orbit. It is enveloped by the meninges and is surrounded by cerebrospinal fluid that enters the subarachnoid space via the chiasmal cistern.Anatomically the nerve can be divided into orbital and intracanalicular portions. The widest part of the orbital portion is adjacent to the ocular globe and is called the bulbar segment. It is followed by the mid-orbital segment (Fig 1).Although many studies on the cranial meninges are available, relatively few deal exclusively with the meninges of the optic nerve and the structures, such as trabeculae and septa, within its subarachnoid space. Anderson described arachnoid trabeculae stretching between the arachnoid layer and the pia layer in the subarachnoid space in the optic...

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“…11 Studies demonstrate that CSF is turned over up to 5 times a day in normal individuals, and large volumes of CSF may be replenished rapidly after removal through lumbar puncture. [14][15][16][17][18] If indeed the locally measured pressure during lumbar puncture equals the ICP (ventricles, cisterns, and SAS) and if there is free communication between the suprasellar cistern and the SAS-ON, then both CSF pressure and content should be equal in the SAS of both optic nerves, and the papilledema should be symmetric. A homogenous CSF pressure has for a long time been assumed, although variations in different CSF spaces have been described.…”

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confidence: 99%

Compartmentalized Cerebrospinal Fluid

Killer¹,

Subramanian²

2014

International Ophthalmology Clinics

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The brain, spinal cord, and the optic nerve are surrounded by and bathed in cerebrospinal fluid (CSF). CSF is produced mainly by the choroid plexus epithelium and ependymal cells of the ventricles from where it flows into interconnecting chambers-the cisterns and the subarachnoid spaces (SASs). 1,2 It is assumed that there is a free and constant circulation of fluid from the sites of production in the third, fourth, and lateral ventricles to the cisterns and SASs.The mechanism by which CSF is driven from its site of production to reabsorption is not yet fully understood, but CSF flow is influenced by the release of newly produced CSF (causing a pressure gradient), the ventricular pulsations, and the pulse pressure of the vascular choroid. The main site of resorption is at the arachnoid villi. Additional possible sites of absorption are the lymphatic capillaries in the dura of the optic nerve and in the area of the olfactory bulb, as well as the dura of the spinal roots. 3-5 A newly discovered mechanism for resorption of CSF acts by means of the meningoepithelial cells (MEC) that cover the arachnoid, the pia, and the trabecular meshwork as well as the septae in the SAS of the optic nerve. 6,7 MECs are found to be more abundant in patients with primary open-angle glaucoma than in normal subjects. 8 In addition, an in vitro study demonstrated MEC proliferation of up to 20% when MECs were exposed to extrinsic increased pressure. 6 Proliferation of MECs was also demonstrated in an animal model after ligation of the optic nerve close to the optic canal. 9 It may thus be postulated that an increase in both the number and volume of MECs will result in a narrowing of the SAS and potentially reduce free CSF flow.

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Unilateral and Asymmetric Optic Disk Swelling with Intracranial Abnormalities

Cited by 37 publications

References 4 publications

A Comparison of Idiopathic Intracranial Hypertension With and Without Papilledema

A Comparison of Idiopathic Intracranial Hypertension With and Without Papilledema

Architecture of arachnoid trabeculae, pillars, and septa in the subarachnoid space of the human optic nerve: anatomy and clinical considerations

Compartmentalized Cerebrospinal Fluid

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