6.2 Orbital Symptoms |
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Fig. 6.3 a–c. Conjunctival injection (eye redness) in a DCSF. Symptoms in DCSFs can be similiar to that of direct CCF patients, but are usually milder and develop less dramatically. A bruit is infrequently reported. This 86-year-old woman presented in March 2002 with mild exophthalmos, eye redness and 6th cranial nerve palsy (a). The close-up shows the typical “corkscrew” dilation of epibulbar veins, which can be considered pathognomonic for DCSFs (b). The type of venous drainage (anterior or posterior) may determine the clinical presentation. This fistula’s drainage involves anteriorly the SOV (arrow), and posteriorly the SPS (dotted arrow), the anterior pontomesencephalic vein, basal vein of Rosenthal and leptomeningeal veins of the posterior fossa (c). Only some of the patients with retrograde cortical or leptomeningeal venous drainage present with venous ischemia or hemorrhage. In most cases, the clinical symptoms are purely opththalmological. Treatment was performed using TVO (see Chap. 8, Fig. 8.4)
Conjunctival chemosis is defined as an edema of the sclera and occurs in 25%–90% (Palestine et al. 1981; Kupersmith et al. 1988; Vinuela et al. 1984) of the cases, accompanying conjunctival injection in patients with DCSFs. In particular, when exophthalmos occurs, it may cause significant prolapse of the conjunctiva with lagophthalmos and trophic damages of the cornea (Figs. 6.4, 6.4). Chemosis may occur before proptosis and is invariably limited to the inferior palpebral conjunctiva (Miller 1998).
6.2.2.1
Retinal Hemorrhage
In severe cases of venous dilation and elevated intravenous pressure, optic disc swelling and retinal hemorrhages, caused by venous stasis and impaired retinal blood flow, with secondary ischemia or hy-
poxia, can occur (Fig. 6.5) (see Case Report I). These intraretinal hemorrhages can be both, flame-shaped (located in the nerve fiber layer) and punctuate (located in the outer retinal layers) (Miller 1998) and can be associated with central retinal vein occlusion (Kupersmith et al. 1996). De Keizer (2003) as well as Stiebel-Kalish et al. (2002) found them in up 18% of their patients.
6.2.3
Corneal Damage
Dehydration of the cornea, usually painful, caused by lagophthalmos, is the main cause for cornea irritations in patients with DCSFs. Therapeutic management of this exposure; a keratopathy may be complicated by dysfunction of the facial nerve with
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6 Neuro-Ophthalmology in Dural Cavernous Sinus Fistulas (DCSFs) |
Fig. 6.4. Severe chemosis in a misdiagnosed DCSF. Despite repeated imaging studies including MRI and CT, the correct diagnosis in this 73-year-old woman was delayed for more than 4 months. During this period, her differential diagnoses included conjunctivitis, maxillo-facial tumor and orbital phlegmone. She underwent extractions of nine (!) teeth, held responsible for her “infectious process”. The patient presented with retroorbital pain, exophthalmos, swelling and redness of her right eye with significant chemosis and visual loss (IOP 23 mmHg) when she was admitted in July 2000. Such chemosis with arterialized conjunctival and episcleral veins may be indistinguishable from that of a direct CCF (see also Case Report III).
Fig. 6.5. Retinal hemorrhages in a DCSF. This 56-year-old woman presented in October 2000 with bilateral proptosis and eye-redness after not being correctly diagnosed for more than 22 months. The fundoscopy shows venous dilation and significant optical nerve swelling. Extensive flame-shaped (superficial) and some punctuate (deep) intraretinal hemorrhages, probably caused by central retinal vein occlusion. (see also Case Report I)
paresis of the “orbicular oculi muscle” and reduced lacrimation. Progressive damages of the corneal epithelium can be initially painless but may lead to local infections, corneal ablations – and ulcerations and beside local hydration and antibiosis often a temporary tarsorrhaphy (eyelids partially sewn together) becomes necessary. Due to variform clinical manifestations, considering differential diagnoses is essential for optimizing therapy of patients with a prolapsed reddish eye bulb. In general, bulb-com- pressing methods should be avoided to minimize the risk of subconjunctival bleedings in case of an underlying arteriovenous fistula. Differential diagnoses include mainly thyroid related orbitopathy (most common cause of unilateral and bilateral proptosis in adults), neoplastic diseases (lymphoma, primary and secondary CNS tumors, in children particularly rhabdoid tumors and sarcomas), allergic reactions, inflammations (viral/bacterial conjunctivitis, myositis), vascular and pseudotumors of the orbit as well as intraorbital bleedings (post-traumatic, paraneoplastic).
6.2.4 Orbital Bruit
The bruit (French word for noise) over the temporal bone or the orbit can be subjective and/or objective (auscultatory) and is usually synchronous with the heartbeat. It may appear as a buzzing, swishing or roaring and represents one classical symptom of high-flow CCFs. It is found in only 25% of patients with DCSFs, mainly in cases with posterior drainage (Halbach et al. 1987). The bruit develops due to arteriovenous turbulences within the CS, which may reach the inner ear organ via sound transmission through the skull. It may increase due to spontaneous occlusion of fistula feeder or during physical exercise or increase of blood pressure. Otherwise, the bruit may decrease or completely disappear following thrombosis, spontaneous occlusion of fistula feeder or during manual compression of the carotid artery in the neck. Bruit, commonly considered a benign symptom, can become a great source of annoyance preventing some patients from sleeping (Madsen 1970). I have observed a patient with a DAVF of the sigmoid sinus who was unable to carry on his profession due to the distress. However, such severe discomfort caused by bruit is rare in DCSFs. A bruit may also not be reported because it is not very intense, the patient has got used to