Contrast-induced neurotoxicity presented as transient cortical blindness after stent-assisted coiling of a medium-sized unruptured basilar artery aneurysm: A case report and review of the literature

Background:

Contrast-induced neurotoxicity is a rare event after endovascular diagnostic procedures or interventions and presents as transient neurological deficit. Herewith, we present a case of reversible complete cortical blindness after uneventful stent-assisted coiling of a medium-sized unruptured basilar artery aneurysm.

Case Description:

A 70-year-old woman with a medium-sized 10 mm/6 mm wide neck basilar tip aneurysm was planned for endovascular obliteration of the lesion. The procedure was done under general anesthesia. The contrast agent was iso-osmolar, nonionic. The aneurysm was coiled, and a stent was placed in the left posterior cerebral artery achieving sufficient aneurysm packing. No signs of vessel obliteration were observed during the procedure. On awakening of anesthesia, the patient reported complete visual loss. Ophthalmological examination was normal. The patient was brought back to the angio-suite but there were no signs of parent vessel compromise from the endovascular implants or distal vessel occlusion. An MRI of the brain was done showing no signs of brain ischemia, just mild brain edema in both occipital lobes. Given the results of the radiological studies and clinical presentation, the diagnosis of contrast-induced neurotoxicity was accepted. In 72 h, the patient had complete resolution of the visual loss and was discharged home with no additional neurological worsening.

Conclusion:

Contrast-induced neurotoxicity is a rare event that can occur after uneventful endovascular interventions of the brain vessels. Knowledge of this rare complication, after exclusion of all other possible reversible causes, is important for the treatment and prognosis of the patient.

Contrast-induced encephalopathy mimicking total anterior circulation stroke: a case report and review of the literature

INTRODUCTION

Contrast-induced encephalopathy is a rare and usually reversible entity due to the administration of iodinated contrast. Clinical manifestations include cortical blindness, encephalopathy, seizures and focal neurological deficits.

METHODS

We report the case of a 56-year-old woman who developed global aphasia and right hemiplegia after a cerebral angiography performed for a subarachnoid haemorrhage. A prompt brain MRI resulted negative, while CT scan revealed left cerebral oedema with the cerebral sulci effacement. Complete recovery was observed in 10 days.

DISCUSSION

Diagnosis of contrast-induced encephalopathy requires a temporal correlation between neurological dysfunction and administration of iodinated contrast. Usually, the symptomatology is transient with a full recovery within 48-72 h. The most common symptom is cortical blindness, while other symptoms have been rarely reported. Only 20 cases previously reported global aphasia and/or hemiplegia or mimed anterior circulation strokes. Prompt brain neuroimaging is essential in order to exclude an alternative diagnosis that requires a distinct therapeutic approach.

Cerebral Lipiodol Embolism after Lymphatic Embolization for Plastic Bronchitis

An adolescent with plastic bronchitis due to congenital heart disease had altered mental status after an interventional lymphatic procedure in which lipiodol contrast was used. Neuroimaging revealed cerebral lipiodol embolization due to direct shunting between lymphatic channels and pulmonary veins. Cerebral lipiodol embolization is a potential neurologic morbidity associated with interventional lymphatic procedures.

An atypical case of contrast-induced encephalopathy after carotid artery stenting

Neurotoxicity caused by contrast agents is a rare and less known complication of percutaneous carotid and coronary interventions. Radiological signs, such as cortical enhancement and brain edema, are of utmost importance in diagnosis. A 70-year-old female patient underwent left carotid artery stenting to treat a post-traumatic asymptomatic carotid dissection. Three hours after intervention, a mild aphasia developed with no brain alteration on diffusion-weighted magnetic resonance imaging (DW-MRI). Twelve hours after intervention, symptoms worsened but a new DW-MRI scan showed no pathological findings. Since a contrast-induced encephalopathy was diagnosed, fluid administration was raised to 2 mL/kg/h and the neurological status progressively improved. In the following three days, neurological deficit slowly regressed. Two weeks after intervention, aphasia had disappeared and a further cerebral DW-MRI scan detected no brain alteration. Typical radiological signs are described in association to contrast encephalopathy. Nevertheless, vascular interventional physicians should be well aware of this condition also when those signs are lacking.

Persistent neurological deficit from iodinated contrast encephalopathy following intracranial aneurysm coiling. A case report and review of the literature

Neurotoxicity from iodinated contrast agents is a known but rare complication of angiography and neurovascular intervention. Neurotoxicity results from contrast penetrating the blood-brain barrier with resultant cerebral oedema and altered neuronal excitability. Clinical effects include encephalopathy, seizures, cortical blindness and focal neurological deficits. Contrast induced encephalopathy is extensively reported as a transient and reversible phenomenon. We describe a patient with a persistent motor deficit due to an encephalopathy from iodinated contrast media administered during cerebral aneurysm coiling. This observation and a review of the literature highlights that contrast-induced encephalopathy may not always have a benign outcome and can cause permanent deficits. This potential harmful effect should be recognised by the angiographer and the interventionalist.

Transient encephalopathy from angiographic contrast: a rare complication in neurointerventional procedures

Neurotoxicity from contrast media used in angiography is a rare complication from these procedures. The infrequency with which it is encountered makes it a diagnostic challenge. We present the case of a 51-year-old male who, 30 min after successful angiography for treatment of a right carotid-ophthalmic fusiform aneurysm with a stent, developed psychomotor agitation, disorientation, and progressive left faciobrachial hemiparesis (4/5). An emergency nonenhanced CT showed marked cortical enhancement and edema in the right cerebral hemisphere. Cortical enhancement is thought to be secondary to contrast extravasation due to disruption of the blood-brain barrier. Angiography was performed immediately, without any pathologic findings. After this procedure there was an increase in the left faciobrachial hemiparesis (3/5), right gaze deviation, Gerstmann syndrome, and left anosognosia and left homonymous hemianopsia. Endovenous dexamethasone and mannitol were initiated. Twenty-four hours later an MRI showed no signs of acute infarct, just gyriform signal increase in the right cerebral hemisphere on FLAIR and a decrease in the edema observed before. The patient had progressive improvement of his neurological deficit. A control MRI done 5 days later was normal. The patient recovered completely and was discharged. This rare entity should be kept in mind but diagnosed only when all other causes have been ruled out, because more important and frequent causes, such as acute infarct, must be excluded promptly.

Cortical blindness, transient and otherwise, associated with detachable coil embolization of intracranial aneurysms

BACKGROUND AND PURPOSE

Cortical visual loss is a rare complication of cerebral angiography without a definitive pathophysiology. Given the rapid increase in endovascular procedures used to treat cerebral aneurysms, we explored the prevalence of this complication and whether we could add to the understanding of this disorder.

MATERIALS AND METHODS

We performed a retrospective review of all procedures performed with the same contrast agent and detachable coils for treatment of posterior circulation aneurysms by 1 endovascular surgery service from 1996 to 2006. All patients were evaluated before and after each procedure by a team that included a neuro-ophthalmologist.

RESULTS

Of 137 intra-arterial treatment procedures performed for posterior circulation aneurysms, we identified 4 patients with cerebral vision loss complications. During the same time period, >500 aneurysms of the anterior cerebral circulation were treated without this complication. The visual field loss was unilateral in 2 and bilateral in 2 patients. Recovery was complete in 3 and almost normal in the fourth patient. The amount of contrast used and the duration of the procedure were similar among all patients. The 4 patients had no identified specific risk factors for developing procedure-associated occipital dysfunction, all 4 had undergone prior angiography, and 1 patient had undergone repeat coiling, without complication.

CONCLUSION

The 2.9% prevalence of cerebral visual loss with endovascular coil treatment of posterior circulation aneurysms is higher than that for angiography alone. Our patients recovered well with corticosteroid and intravenous hydration treatment. Recognizing the self-limiting nature of this problem might prevent an unneeded intervention.

Cortical blindness during coil embolization of an unruptured intracranial aneurysm--case report

A 62-year-old woman suffered transient cortical blindness during coil embolization for a saccular aneurysm in the posterior circulation, with cerebral angiography using non-ionic contrast material. Just before completion of the procedure, the patient showed abrupt onset of restlessness and blindness. At this point 150 ml of contrast material had been injected into the left vertebral artery. Immediate computed tomography showed persistence of contrast medium in the bilateral occipital lobes and part of the left frontal lobe. Repeat angiography showed no evidence of embolism. Single photon emission computed tomography obtained the next day showed decreased perfusion in the bilateral occipital lobes. Magnetic resonance imaging on the third day showed multiple lesions in the bilateral occipital lobes. Her vision was restored gradually. Transient cortical blindness may be associated with osmotic disruption of the blood-brain barrier in the bilateral occipital lobes. Endovascular neurosurgeons must be aware of this rare complication.

Cortical blindness after subclavian arteriography

Transient cortical blindness is a rare complication of angiographic contrast use. A 64-year-old man experienced transient cortical blindness after subclavian arteriography for an occluded axillofemoral graft. The literature on transient cortical blindness is reviewed.

Transient cortical blindness following bypass graft angiography. A case report

Transient cortical blindness, an uncommonly recognized complication of cerebral angiography, is an exceedingly rare event after cardiac catheterization and angiography. This report describes a sixty-two-year-old patient who had transient cortical blindness following bypass graft angiography. In this case, the authors showed that cortical blindness was associated with the breakage of the blood-brain barrier (BBB) and an increase in vascular permeability rather than with primary cerebral circulatory insufficiency. When the possibility exists that an excess volume of contrast medium may enter the cerebral circulation as in this case, that is, following a coronary artery bypass graft (CABG) using the internal mammary artery (IMA), precautionary measures may be necessary such as changing the type of contrast medium to be used or decreasing the volume injected. When cortical blindness occurs, it is a serious clinical problem whether transient or permanent. Therefore, the circumstances leading to this complication should be understood to determine suitable treatment and management.

Neurotoxicity of water-soluble contrast media

A review is given of the development of the water-soluble contrast media (CM) with particular attention to the frquency of neurological complications. A remarkable improvement was achieved following the introduction of the nonionic agent metrizamide in 1974, and a further decrease in neurotoxicity was obtained with the newer nonionic monomers, which have multlple hydroxyl groups included at different sites of the molecule. Theoretical considerations and experimental studies suggest that the neurotoxicity of the new nonionic dimeric agents shuold be at least within the low range seen with the monomeric ones, but further experience is needed before definite conclusions can be drawn in this respect. The mechanisms responsible for the neurological complications seen with CM are unknown but certain critical groups on the CM molecules are known. Several animal models have been developd, which may help predict the degree of neurotoxicity.

A method to quantitatively measure transcapillary transport of iodinated compounds in canine brain tumors with computed tomography

We present a quantitative method for determining a blood-to-tissue influx constant (K1), a tissue-to-blood efflux constant (k2), and tissue plasma vascular space (Vp) that uses a computed tomographic (CT) scanner to make tissue and plasma measurements of the concentration of an iodinated compound. Meglumine iothalamate was infused intravenously over time periods of 0.5-5 min, up to 49 CT scans were obtained at one brain level, and arterial plasma was sampled over a 30- to 40-min period. K1, k2, and Vp were calculated for each voxel of the 320 x 320 matrix, using a two-compartment pharmacokinetic model and nonlinear least-squares regression. The method was used in dogs with avian sarcoma virus-induced brain tumors. As many as four studies on different days were done in the same animal. In tumor-free cortex, K1 of meglumine iothalamate was 2.4 +/- 1.7 microliter g-1 min-1 (mean +/- SD) and Vp was 3.4 +/- 0.5 ml 100 g-1. Mean whole-brain tumor K1 values ranged from 3.3 to 97.9 microliters g-1 min-1; k2 ranged from 0.032 to 0.27 min-1; and Vp ranged from 1.1 to 11.4 ml 100 g-1. These values were reproducible in serial experiments in single animals. Independent verification of K1 values was obtained with quantitative autoradiographic measurements of alpha-aminoisobutyric acid, which has similar physicochemical properties to meglumine iothalamate. The CT methodology is capable of demonstrating regional variation of transcapillary transport in brain tumors and may be of value in the study of human brain tumors.