Dural arteriovenous fistula-induced thalamic dementia: report of 4 cases.

Nonhemorrhagic neurological deficits are underrecognized symptoms of intracranial dural arteriovenous fistulas (dAVFs) having cortical venous drainage. These symptoms are the consequence of cortical venous hypertension and portend a clinical course with increased risk of neurological morbidity and mortality. One rarely documented and easily misinterpreted type of nonhemorrhagic neurological deficit is progressive dementia, which can result from venous hypertension in the cortex or in bilateral thalami. The latter, which is due to dAVF drainage into the deep venous system, is the less common of these 2 dementia syndromes. Herein, the authors report 4 cases of dAVF with venous drainage into the vein of Galen causing bithalamic edema and rapidly progressive dementia. Two patients were treated successfully with endovascular embolization, and the other 2 patients were treated successfully with endovascular embolization followed by surgery. The radiographic abnormalities and presenting symptoms rapidly resolved after dAVF obliteration in all 4 cases. Detailed descriptions of these 4 cases are presented along with a critical review of 15 previously reported cases. In our analysis of these 19 published cases, the following were emphasized: 1) the clinical and radiographic differences between dAVF-induced thalamic versus cortical dementia syndromes; 2) the differential diagnosis and necessary radiographic workup for patients presenting with a rapidly progressive thalamic dementia syndrome; 3) the frequency at which delays in diagnosis occurred and potentially dangerous and avoidable diagnostic procedures were used; and 4) the rapidity and completeness of symptom resolution following dAVF treatment.

Deep arteriovenous malformations in the basal ganglia, thalamus, and insula: multimodality management, patient selection, and results.

OBJECTIVE: This study sought to describe a single institution's experience treating arteriovenous malformations (AVMs) of the basal ganglia, thalamus, and insula in a multimodal fashion. METHODS: We conducted a retrospective review of all deep AVMs treated at our institution between 1997 and 2011 with attention to patient selection, treatment strategies, and radiographic and functional outcomes. RESULTS: A total of 97 patients underwent initial treatment at our institution. 64% presented with hemorrhage with 29% located in the basal ganglia, 41% in the thalamus, and 30% in the insula. 80% were Spetzler-Martin grade III-IV. Initial treatment was microsurgical resection in 42%, stereotactic radiosurgery (SRS) in 45%, and observation in 12%. Radiographic cure was achieved in 54% after initial surgical or SRS treatment (71% and 23%, respectively) and in 63% after subsequent treatments, with good functional outcomes in 78% (median follow-up 2.2 years). Multivariate logistic regression analysis revealed treatment group and age as factors associated with radiographic cure, whereas Spetzler-Martin score and time to follow-up were significantly associated with improved/unchanged functional status at time of last follow-up. Posttreatment hemorrhage occurred in 11% (7% of surgical and 18% of SRS patients). CONCLUSIONS: Modern treatment of deep AVMs includes a multidisciplinary approach utilizing microsurgery, SRS, embolization, and observation. Supplementary grading adds meaningfully to traditional Spetzler-Martin grading to guide patient selection. Surgical resection is more likely to result in obliteration compared with SRS, and is associated with satisfactory results in carefully selected patients.

Redefining thalamic vascularization vicariously through gerald percheron: a historical vignette.

Gerard Percheron, M.D., a practicing neurologist and prolific researcher at the Institute Nationale de la Sante et de la Recherche Medicale (INSERM), made significant and valuable contributions to medicine, in particular, to the vascular anatomy of the basal ganglia. His particular interest in the thalamus eventually led to the identification of an anatomic variation in its vascular supply. This newly identified artery was subsequently named the artery of Percheron (AOP). Given the estimated prevalence of the AOP in up to one third of the population and its significant proportion of all thalamic infarcts, it is necessary for physicians to be aware of this anatomic vascular variant and its clinical consequences. Although occlusion of the AOP may present similar to other arterial thalamic occlusions, it can be identified through susceptibility-weighted imaging and ruled out with conventional or magnetic resonance angiography. Occlusion of the AOP typically causes a simultaneous and symmetric infarction. Treatment efficacy is time-dependent and necessitates thrombolytics and anticoagulative medications. Here, we trace a course from the artery's initial description in 1973 to its current implications in cerebrovascular stroke, and offer a synopsis of the proposed treatment.

Cognitive decline and hypersomnolence: thalamic manifestations of a tentorial dural arteriovenous fistula (dAVF).

BACKGROUND: Intracranial dural arteriovenous fistulas (dAVFs) often present with pulsatile tinnitus, orbital congestion, and headache. Occasionally, they present with focal neurologic deficits, a dementia-like syndrome, hemorrhage, or ischemic infarction. METHODS: This study is based on the case of a 71-year-old gentleman who presented with 6 months of progressive forgetfulness, inattention, and hypersomnolence. Four weeks prior to presentation, he developed symptoms of left-sided pain, numbness, and worsening weakness. Neurologic examination demonstrated hypersomnolence, a score of 30/38 on the Kokmen Short Test of Mental Status, and left hemiparesis. MRI brain revealed bilateral thalamic T2 hyperintensities with associated enhancement. MR venogram (MRV) showed a vascular malformation in the posterior fossa and occlusion of the straight sinus. Conventional cerebral angiogram confirmed a tentorial dAVF. The dAVF was definitively treated with transarterial embolization, followed by clip ligation of the arterialized draining vein. Twelve weeks later, there was clinical resolution of left hemiparesis and improvement in cognitive status. MRI revealed complete resolution of the thalamic hyperintensities. MRV demonstrated recanalization of the straight sinus. RESULTS: Intracranial dAVFs are uncommon but potentially life-threatening acquired vascular malformations. The initiating factor is venous hypertension, causing retrograde flow, venous congestion, ischemia, and sometimes infarction. The spectrum of clinical manifestations in dAVFs reflects the degree of venous congestion present. If retrograde venous flow is surgically obliterated, then venous hypertension may be reversible. Bilateral thalamic venous congestion can present as a thalamic dementia. CONCLUSION: We conclude that intracranial dAVFs with thalamic venous congestion should be considered in the diagnostic differential for patients who present with subacute cognitive decline and T2 hyperintense thalamic signal change.

Neuropyschological profile of reversible cognitive impairment in a patient with a dural arteriovenous fistula.

OBJECTIVE AND IMPORTANCE: Patients with dural arteriovenous fistulas (dAVFs) may present with cognitive impairment secondary to venous hypertension or ischemia. CLINICAL PRESENTATION: We present a patient with a dAVF supplied by the posterior meningeal artery who presented with severe encephalopathy and imaging consistent with bilateral thalamic ischemia. RESULTS: Detailed pre-operative neuropsychological testing documented severe cognitive deficits across multiple domains, localizing diffusely in the cerebral cortex, beyond that which would be expected from purely thalamic involvement. Approximately 2 months following a combined endovascular and surgical repair, repeat neuropsychological testing documented a dramatic improvement in cognitive symptoms while MRI abnormalities in the thalami resolved. CONCLUSION: Detailed neuropsychological testing may be useful in patients presenting with dAVFs in order to identify cognitive impairment, which may be out of proportion to imaging findings. Recognition of dAVF-associated cognitive impairment may lead to more aggressive, timely treatment in patients with otherwise lower-risk lesions. This detailed testing can also provide a baseline in order to document cognitive recovery after fistula repair.

Treatment of cavernous sinus dural arteriovenous fistulae by external manual carotid compression.

OBJECTIVE: External manual carotid compression is a noninvasive method to treat cavernous sinus (CS) dural arteriovenous fistulae (DAVF). We studied a group of patients with CS-DAVF to identify what factors made complete resolution of their clinical symptoms and closure of the DAVF on magnetic resonance angiography (MRA) by compression therapy possible. METHODS: We treated 23 patients with CS-DAVF without cortical venous drainage or a recent decline in visual acuity by compression therapy. All were followed up by magnetic resonance angiography at 1, 3, 6, and 12 months after treatment and the characteristics of the imaging findings, their neurological symptoms, and the patterns of symptom improvement were examined. RESULTS: In Group A (n = 8), complete resolution was achieved by manual carotid compression. In the other 15 patients (Group B), complete resolution was not obtained. Group B manifested significantly higher ocular pressure and a significantly longer interval between symptom onset and compression treatment. In Group A, venous drainage was via the superior orbital vein with or without involvement of the inferior petrosal sinus. Closure of the CS-DAVF occurred within 4.1 months after the start of treatment. In three patients, symptom improvement progressed steadily and gradually. The other five patients with complete resolution experienced transient worsening of their symptoms at 2 to 4 months after the start of treatment and symptom resolution occurred within 4 to 7 months. CONCLUSION: We identified lower ocular pressure, a shorter interval between symptom onset and compression treatment, and venous drainage solely via the superior orbital vein without involvement of the inferior petrosal sinus as the factors in our CS-DAVF patients that made complete resolution by manual carotid compression possible.

Dural arteriovenous fistulas with aggressive course: clinical and angiographic correlations in two patients.

Cranial dural arteriovenous fistulas (DAVFs) usually present with non-aggressive symptoms. We here report two patients who presented a peculiar clinical picture related to DAVFs, with focal neurological signs and haemorrhagic (case 1) or ischaemic lesions (case 2) respectively. The clinical and angiographic findings and putative pathophysiological mechanisms are discussed.