Clinical Pathways in Neuro-ophthalmology : An ... - E-Lib FK UWKS

136 Clinical Pathways in Neuro-Ophthalmology, second edition
granulations by diffuse convexity meningiomatosis (Thomas, 1999). Kieper et al noted
that 5 of 107 patients who underwent suboccipital craniotomy or translabyrinthine
craniectomy developed PTC (Kieper, 1999). In each patient, the transverse sinus on the
treated side was thrombosed, and patency of the contralateral sinus was confirmed on
MRI. PTC has also been described after arteriovenous malformation embolization
(Kollar, 1999). Sluggish flow in a venous varix after embolization, resulting in
thrombosis that was propagated to vein of Galen, was the proposed mechanism.
Ligation of one or both jugular veins (e.g., radical neck dissection), thrombosis of a
central intravenous catheter in the chest or neck, subclavian vein catheterization and
arteriovenous fistula, the superior vena cava syndrome, or a glomus jugular tumor
impairing venous drainage may also cause increased intracranial pressure. Osteopetrosis
causing obstruction of venous outflow at the jugular foramen has also been
reported (Ageli, 1994; Kiers, 1991; Lam, 1992; Siatkowski, 1999). Venous sinus thrombosis
may be the mechanism for PTC reported in several conditions including systemic
lupus erythematosus, essential thrombocythemia, protein S deficiency, antithrombin III
deficiency, the antiphospholipid antibody syndrome, activated protein C resistance,
paroxysmal nocturnal hemoglobinuria, Behçet’s disease, meningeal sarcoidosis,
lymphoma, hypervitaminosis A, mastoiditis, and trichinosis (Akova, 1993; Biousse,
1999; Daif, 1995; Farah, 1998; Gironell, 1997; Hauser, 1996; Leker, 1998; Mokri, 1993;
Pelton, 1999; Provenzale, 1998). In fact, elevated intracranial venous pressure is thought
by some authors to be the universal mechanism of PTC of varying etiologies, including
idiopathic PTC (Cremer, 1996; Karahalios, 1996; King, 1995). Higgins et al presented a
case of PTC thought secondary to bilateral transverse sinus stenosis discovered on
venography that was treated successfully by inserting a self-expanding stent across
the stenosis in the right transverse sinus (Higgins, 2002). These authors suggest that the
transverse sinus pathology was not thrombosis but an idiopathic narrowing of the
transverse sinus bilaterally.
Biousse et al noted that central venous thrombosis (CVT) can present with all the
classic criteria for idiopathic pseudotumor cerebri, including normal CT imaging and
CSF contents (Biousse, 1999). Of 160 consecutive patients with CVT, 59 patients (37%)
presented with isolated intracranial hypertension. Neuroimaging revealed involvement
of more than one venous sinus in 35 patients (59%); CT imaging was normal in 27 of 50
patients (54%). The superior sagittal sinus was involved in 32 patients (54%) (isolated in
7) and the lateral sinus in 47 (80%) (isolated in 17). The straight sinus was thrombosed
in eight patients, cortical veins were involved in two patients, and deep cerebral
veins in three, always in association with thrombosis in the superior sagittal sinus
or lateral sinuses. Lumbar puncture was performed in 44 patients and showed elevated
opening pressure in 25 of 32 (78%) and abnormal CSF contents in 11 (25%). Etiologic
risk factors included local causes (7), surgery (1), inflammatory disease (18), infection
(2), cancer (1), postpartum (1), coagulopathies (11), and oral contraception (7).
The cause was unknown in 11 cases (19%). Anticoagulants were used in 41 of 59
patients (69%), steroids or acetazolamide in 26 (44%), therapeutic lumbar puncture in 44
(75%), and surgical shunt in 1. Three patients had optic atrophy with severe visual loss,
one died from carcinomatous meningitis, and 55 (93%) had complete recovery
(although visual field testing was not systematically performed). The authors emphasized
that MRI and MR venography should be considered in presumed isolated
intracranial hypertension.