Faculty Bibliography

OBJECT: The authors sought to treat potentially catastrophic intracranial dural and deep cerebral venous thrombosis by using a multimodality endovascular approach. METHODS: Six patients aged 14 to 75 years presented with progressive symptoms of thrombotic intracranial venous occlusion. Five presented with neurological deficits, and one patient had a progressive and intractable headache. All six had known risk factors for venous thrombosis: inflammatory bowel disease (two patients), nephrotic syndrome (one), cancer (one), use of oral contraceptive pills (one), and puerperium (one). Four had combined dural and deep venous thrombosis, whereas clot formation was limited to the dural venous sinuses in two patients. All patients underwent diagnostic cerebral arteriograms followed by transvenous catheterization and selective sinus and deep venous microcatheterization. Urokinase was delivered at the proximal aspect of the thrombus in dosages of 200,000 to 1,000,000 IU. In two patients with thrombus refractory to pharmacological thrombolytic treatment, mechanical wire microsnare maceration of the thrombus resulted in sinus patency. Radiological studies obtained 24 hours after thrombolysis reconfirmed sinus/vein patency in all patients. All patients' symptoms and neurological deficits improved, and no procedural complications ensued. Follow-up periods ranged from 12 to 35 months, and all six patients remain free of any symptomatic venous reocclusion. Factors including patients' age, preexisting medical conditions, and duration of symptoms had no statistical bearing on the outcome. CONCLUSIONS: Patients with both dural and deep cerebral venous thrombosis often have a variable clinical course and an unpredictable neurological outcome. With recent improvements in interventional techniques, endovascular therapy is warranted in symptomatic patients early in the disease course, prior to morbid and potentially fatal neurological deterioration.

The causes of sixth nerve palsies in 75 children, all of whom had undergone modern neuroimaging, were reviewed. Neoplasms or their neurosurgical removal was the most common cause (n = 34 [45%]); elevated intracranial pressure (nontumor) (15%), traumatic (12%), congenital (11%), inflammatory (7%), miscellaneous (5%), and idiopathic (5%) causes represented other categories but were less commonly present. Isolated sixth nerve palsies were relatively uncommon (9%). On the basis of the relatively high risk of neoplasm, the authors suggest neuroimaging early in the clinical course of children with sixth nerve palsies, even if the palsy is isolated.

A tonic pupil may occur in isolation or as part of a systemic disorder. We report a patient who developed tonic pupils and an abduction deficit in the setting of polyarteritis nodosa. The combination of a tonic pupil and an abduction deficit should suggest the possibility of a vasculopathic disorder, because the ciliary ganglion and lateral rectus muscle are both supplied by the lateral muscular artery. Widespread small artery and arteriolar narrowing and occlusion are the hallmarks of polyarteritis nodosa. Unusual ischemic syndromes may occur, such as this rare combination of neuro-ophthalmic signs, by involvement of both the nutrient artery and its collaterals. We are unaware of other reports of neuropathic tonic pupils in association with polyarteritis nodosa.

PURPOSE: Dural arteriovenous fistulas (DAVFs) are acquired arteriovenous shunts located within the dura. The highly variable natural history and symptomatology of DAVFs range from subjective bruit to intracranial hemorrhage and are related to the lesion's pattern of venous drainage and its effect on the drainage of adjacent brain. We examined the prevalence and features of DAVFs in patients with progressive dementia or encephalopathy. METHODS: The records and radiologic studies of 40 consecutive patients with DAVFs treated at our institution were reviewed. RESULTS: Five (12.5%) of 40 consecutive patients with DAVFs had encephalopathy or dementia. In each patient, high flow through the arteriovenous shunt combined with venous outflow obstruction caused impairment of cerebral venous drainage. Hemodynamically, the result was widespread venous hypertension causing diffuse ischemia and progressive dysfunction of brain parenchyma. Results of CT or MR imaging revealed abnormalities in each patient, reflecting the impaired parenchymal venous drainage. Pathologic findings in one patient confirmed the mechanism of cerebral dysfunction as venous hypertension. The hemodynamic mechanism and resulting abnormality appeared identical to that seen in progressive chronic myelopathy resulting from a spinal DAVF (Foix-Alajouanine syndrome). Remission of cognitive symptoms occurred in each patient after embolization. CONCLUSION: Venous hypertensive encephalopathy resulting from a DAVF should be considered a potentially reversible cause of vascular dementia in patients with progressive cognitive deficits

Pseudotumor cerebri is an idiopathic disorder characterized by papilledema and elevated intracranial pressure without a mass lesion. Most patients are female and young and are either overweight or have a history of recent weight gain. Other disease states, such as systemic lupus erythematosus, and drugs, such as tetracycline, have also been associated with the development of pseudotumor cerebri. The mechanism is unclear, but is likely related to decreased cerebrospinal fluid (CSF) resorption. Almost all patients have headache, but the greatest morbidity of the disorder is visual loss related to optic disc swelling. Common radiographic findings in pseudotumor cerebri include an empty sella, dilation of the optic nerve sheaths and elevation of the optic disc. The CSF, aside from elevated opening pressure, is normal without evidence of infection or inflammation. Treatment of patients with no or mild to moderate visual loss is primarily medical, with acetazolamide as the first-line agent. Acetazolamide decreases CSF production. Furosemide and corticosteroids are secondary choices. Optic nerve surgery is reserved for patients with severe visual loss or progression in visual deficits despite medical management.