Posterior Cerebral Artery Infarction Research Articles

Eine Myokarditis mit gravierenden neurologischen Folgen

A 39-year-old woman developed severe dyspnea subsequent to a respiratory tract infection. Furthermore an acute loss of vision occurred two days prior to admission. DIAGNOSES AND TREATMENT: Left ventricular dilatation due to myocarditis had led to decompensated cardiac insufficiency. The loss of vision (cortical blindness) had been caused by multiple brain infarctions in the posterior cerebral circulation due to basilary artery occlusion subsequent to cardiogenic embolism. During anticoagulation with heparin and antiplatelet drugs a large, space-occupying intracranial hemorrhage occurred in a posterior cerebral artery infarction. Emergency decompressive craniectomy was necessary. Heart insufficiency and left ventricular dilatation resolved later on. Hydrocephalus became obvious after cranioplasty, thus leading to shunt procedure. After long-term neurorehabilitation, accompanied by several complications and two neurosurgical procedures, the patient gained more independence in her activities of daily living and quality of life. In the light of the initial burden of symptoms this course was rather favorable. Myocarditis as a cause for acute heart insufficiency has to be taken into account in young patients without any history of cardiac abnormalities and preceding infections. Cardioembolic stroke may be a consequence. Decisions in secondary stroke prevention should be made on an individual base with regard to medical guidelines as well as risk factors. Neurorehabilitation of sufficient length and quality can lead to functional recovery, improvement of independence in activities of daily living and quality of life, even if the initial situation seems worse and medical complications accompany the course.

Reduced retinal ganglion cell complex thickness in patients with posterior cerebral artery infarction detected using spectral-domain optical coherence tomography

To report a reduction in macular ganglion cell complex (GCC) thickness detected with spectral-domain optical coherence tomography (SD-OCT) in patients with homonymous hemianopia following acquired cerebral damage. We analyzed case reports of three patients with unilateral posterior cerebral artery (PCA) infarction. Three patients (aged 66, 68, and 71 years) with left homonymous hemianopia due to infarction of the right PCA territory were studied using SD-OCT. The duration of the lesions from the onset ranged from 12 to 36 months. In all of these patients, although optic atrophy and retinal nerve fiber layer defects were not detected on funduscopy, GCC thinning was demonstrated in the hemiretinae corresponding to the affected hemifields. Macular GCC measurements showed the localized defects of retinal ganglion cells (RGCs) more clearly than circumpapillary retinal nerve fiber layer measurements. Total and outer retinal thicknesses were not found to be significantly affected. Our findings suggest that degeneration of RGCs can occur within a few years after PCA infarction.

Ependymal Brain Cyst with Posterior Cerebral Artery Infarct

Primary intracranial ependymal cysts are congenital, benign, ependyma-lined cysts rarely seen in the pediatric age group. The authors report such a case of intracranial fronto-parietal ependymal cyst in a 3 y-old girl. Computed tomography showed a large cystic lesion which was not in communication with the ventricular system and was associated with ipsilateral posterior cerebral artery infarct and raised intracranial pressure causing midline shift. A differential diagnosis of the commoner arachnoid, hydatid or porencephalic cyst was considered. Surgical removal to decompress the brain was done; histopathology revealed an ependymal cyst. Identification of this rare pathology in the pediatric age group is emphasized with a review of the literature.

Acute Korsakoff's Psychosis and Disinhibition Syndrome Triggered by a Cortical Posterior Cerebral Artery Infarction (P07.182)

Objective: We report an unusual case of a dominant hemisphere, medial occipital and medial temporal cortical infarction precipitating Korsakoff9s psychosis and a disinhibition syndrome, reminiscent of a frontal lobe phenotype. A 66 year-old, right handed man, while driving to watch the Monaco Grand Prix, developed acute headache and amnesia accompanied by emotional lability, disinhibited behavior, inappropriate laughter and a right homonymous hemianopia. He had deficits in both episodic and working memory, a mild degree of executive dysfunction and a tendency to confabulate. There were no other focal neurological signs. He had been well previously, except for moderately high alcohol consumption. The cognitive deficits persisted 6 months after presentation, despite thiamine replacement. Acute imaging demonstrated restricted diffusion in the medial occipital and temporal lobes involving the fusiform and parahippocampal gyri with sparing of thalamus and other deeper structures. The rest of the parenchymal structures were normal and there was no evidence of small vessel ischaemia. An occlusion of P2 segment of the left posterior cerebral artery and its cortical branches was seen on vascular imaging. Cognitive deficits associated with posterior cerebral artery infarctions include a constellation of behavioural symptoms including transcortical aphasia, alexia without agraphia, Gerstmann syndrome, episodic memory deficit, visual agnosia, prosopagnosia and rarely acute delirium with/without aggressive behavior. Disinhibition syndromes of frontal phenotype have rarely been reported and may be associated with cortical deafferentation following a non-dominant thalamic lesion. This case demonstrates that behavioural deficits after cortical PCA territory infarction are not restricted to memory, language and vision and may occur without thalamic involvement. We hypothesise that the Korsakoff9s syndrome may have been the result of a functional disruption of mamillothalamic connections, as previously described, whereas the frontal behavioural features may be caused by a disruption of occipito temporal and occipito frontal connectivity. Disclosure: Dr. Agarwal has nothing to disclose. Dr. Manford has received personal compensation for activities with UCB Pharma and Eisai.

Neurosyphilis Presenting as Acute Symmetrical Bilateral Posterior Cerebral Artery Infarctions: A Case Report (P03.158)

Neurosyphilis Presenting as Acute Symmetrical Bilateral Posterior Cerebral Artery Infarctions: A Case Report (P03.158)

Visual Agnosia and Posterior Cerebral Artery Infarcts: An Anatomical-Clinical Study

BackgroundTo evaluate systematically the cognitive deficits following posterior cerebral artery (PCA) strokes, especially agnosic visual disorders, and to study anatomical-clinical correlations.Methods and FindingsWe investigated 31 patients at the chronic stage (mean duration of 29.1 months post infarct) with standardized cognitive tests. New experimental tests were used to assess visual impairments for words, faces, houses, and objects. Forty-one healthy subjects participated as controls. Brain lesions were normalized, combined, and related to occipitotemporal areas responsive to specific visual categories, including words (VWFA), faces (FFA and OFA), houses (PPA) and common objects (LOC). Lesions were located in the left hemisphere in 15 patients, in the right in 13, and bilaterally in 3. Visual field defects were found in 23 patients. Twenty patients had a visual disorder in at least one of the experimental tests (9 with faces, 10 with houses, 7 with phones, 3 with words). Six patients had a deficit just for a single category of stimulus. The regions of maximum overlap of brain lesions associated with a deficit for a given category of stimuli were contiguous to the peaks of the corresponding functional areas as identified in normal subjects. However, the strength of anatomical-clinical correlations was greater for words than for faces or houses, probably due to the stronger lateralization of the VWFA, as compared to the FFA or the PPA.ConclusionsAgnosic visual disorders following PCA infarcts are more frequent than previously reported. Dedicated batteries of tests, such as those developed here, are required to identify such deficits, which may escape clinical notice. The spatial relationships of lesions and of regions activated in normal subjects predict the nature of the deficits, although individual variability and bilaterally represented systems may blur those correlations.

Infarctions in the vascular territory of the posterior cerebral artery: clinical features in 232 patients

BackgroundIschemic stroke caused by infarction in the territory of the posterior cerebral artery (PCA) has not been studied as extensively as infarctions in other vascular territories. This single centre, retrospective clinical study was conducted a) to describe salient characteristics of stroke patients with PCA infarction, b) to compare data of these patients with those with ischaemic stroke due to middle cerebral artery (MCA) and anterior cerebral artery (ACA) infarctions, and c) to identify predictors of PCA stroke.FindingsA total of 232 patients with PCA stroke were included in the "Sagrat Cor Hospital of Barcelona Stroke Registry" during a period of 19 years (1986-2004). Data from stroke patients are entered in the stroke registry following a standardized protocol with 161 items regarding demographics, risk factors, clinical features, laboratory and neuroimaging data, complications and outcome. The characteristics of these 232 patients with PCA stroke were compared with those of the 1355 patients with MCA infarctions and 51 patients with ACA infarctions included in the registry.Infarctions of the PCA accounted for 6.8% of all cases of stroke (n = 3808) and 9.6% of cerebral infarctions (n = 2704). Lacunar infarction was the most frequent stroke subtype (34.5%) followed by atherothrombotic infarction (29.3%) and cardioembolic infarction (21.6%). In-hospital mortality was 3.9% (n = 9). Forty-five patients (19.4%) were symptom-free at hospital discharge. Hemianopia (odds ratio [OR] = 6.43), lacunar stroke subtype (OR = 2.18), symptom-free at discharge (OR = 1.92), limb weakness (OR = 0.10), speech disorders (OR = 0.33) and cardioembolism (OR = 0.65) were independent variables of PCA stroke in comparison with MCA infarction, whereas sensory deficit (OR = 2.36), limb weakness (OR = 0.11) and cardioembolism as stroke mechanism (OR = 0.43) were independent variables associated with PCA stroke in comparison with ACA infarction.ConclusionsLacunar stroke is the main subtype of infarction occurring in the PCA territory. Several clinical features are more frequent in stroke patients with PCA infarction than in patients with ischaemic stroke due to infarction in the MCA and ACA territories. In-hospital mortality in patients with PCA territory is low.

Teaching Neuro Images : Posterior cerebral artery susceptibility vessel sign on T2*-weighted gradient echo imaging

A 60-year-old man with atrial fibrillation was admitted due to left posterior cerebral artery (PCA) infarction. Serial T2*-weighted magnetic resonance gradient echo imaging (GRE) before and after thrombolysis demonstrated consecutive changes of the PCA susceptibility vessel sign (SVS) at 3, 7, and 210 hours poststroke with corresponding …

Poststroke Conscious Visual Deficit

Background and Purpose. Little is known about the outcome and recovery mechanisms of visual perception after a focal lesion of the occipital lobe in humans, especially after stroke. In this study, the authors aimed to describe the clinical course and the neural substrates of conscious perceptive visual deficit after posterior cerebral artery infarct. Methods. The authors prospectively included 8 patients (7 men and 1 woman; mean age, 64.6 ± 18 years) with visual deficit induced by partial damage of the striate cortex related to acute posterior cerebral artery infarct. Conscious perception of color and motion was assessed from the acute phase to the third month. Functional magnetic resonance imaging was performed to investigate neural substrates of visual recovery. Results. In the acute phase of stroke, visual deficiency was global (3/8 patients), selective to color (4/8 patients), or selective to motion (1/8 patients). During the follow-up, visual performance increased with respect to color (from 29% to 70%; P < .005) and with respect to motion (from 47% to 74%; P < .005). Despite a lack of ipsilesional V1 area activation in the acute phase, activations in this area and in the contralesional extrastriate cortex were obtained during follow-up. Both ipsilesional and contralesional V4 activations were correlated with better outcome. Conclusions. Extensive visual recovery occurs early after partial acute posterior cerebral artery infarct. Spared islands in ipsilesional V1 area and transcallosal pathways might be involved in poststroke visual recovery.

Bilateral homonymous superior quadrantanopia after traumatic attempts to remove a cockroach impacted in the external auditory canal

Visual field defects typically caused by lesions in the optic nerve or optic chiasm may be caused indirectly by subdural haematomas. A 61-year-old man survived transtentorial herniation caused by subdural haematomas that resulted from shaking his head in an attempt to remove a cockroach impacted in his external auditory canal. Bilateral incomplete posterior cerebral artery infarction of both inferior tips of the occipital lobe resulted in bilateral superior quadrantanopia. There are no previous reports of tentorial herniation causing this permanent outcome.

Long-term outcome in posterior cerebral artery stroke

Previous studies on posterior cerebral artery (PCA) strokes focused mainly on topography and underlying pathophysiology. However, there are no data on long-term prognosis and its association with the localization of the infarct. All consecutive PCA strokes registered in the Athens Stroke Outcome Project between 01/1998 and 12/2009 were included in the analysis. The New England Posterior Circulation Registry criteria were applied to classify them in relation to topography: (i) pure PCA infarcts, including pure cortical-only and combined cortical/deep PCA infarcts (groups A and B respectively), and (ii) PCA-plus strokes, including cortical-only and combined cortical/deep PCA strokes with ≥1 concomitant infarcts outside PCA territory (groups C and D respectively). Patients were prospectively followed up to 10 years after stroke. Amongst 185 (8.1%) PCA patients that were followed up for 49.6±26.7months, 98 (53%), 24 (13%), 36 (19.5%), and 27 (14.6%) were classified in group A, B, C, and D, respectively. Infections and brain edema with mass effect were more frequently encountered in PCA-plus strokes compared to pure PCA (P<0.05 and <0.01 respectively). At 6 months, 56% of cortical-only PCA patients had no or minor disability, compared to 37%, 36%, and 26% in the other groups (P=0.015). The 10-year probability of death was 55.1% (95%CI: 42.2-68.0) for pure PCA compared to 72.5% (95%CI: 58.8-86.2) for PCA-plus (log-rank 14.2, P=0.001). Long-term mortality was associated with initial neurologic severity and underlying stroke mechanism. Patients with pure PCA stroke have significantly lower risk of disability and long-term mortality compared to PCA strokes with coincident infarction outside the PCA territory.

Posterior cerebral artery infarction: an understudied vascular topography of ischaemic stroke

Posterior cerebral artery infarction: an understudied vascular topography of ischaemic stroke

Topographic patterns of thalamic infarcts in association with stroke syndromes and aetiologies

ObjectiveTo characterise the topographic patterns of thalamic infarcts associated with various stroke syndromes and aetiologies.MethodsIn this study, 168 consecutive patients with acute infarcts involving the thalamus were investigated by use...

Spontaneous intra-cranial arterial dissection frequently causes anterior cerebral artery infarction

Background and purpose Spontaneous intra-cranial arterial dissection (SICAD) without history of head and neck injury is now recognized as an important cause of stroke. However, the frequency of SICAD involving the anterior cerebral artery (ACA), middle cerebral artery (MCA), and posterior cerebral artery (PCA) territories remains unclear. This study therefore investigated the distribution of SICAD. Methods Subjects comprised 194 patients (126 men, 68 women; median age, 68.0 years) with infarct isolated to the ACA, MCA or PCA territories who underwent conventional angiography. Diagnosis of SICAD was based on clinical and neuroradiological findings. Frequency of SICAD was compared among ACA, MCA, and PCA infarcts. All patients were divided into SICAD and non-SICAD groups, and clinical characteristics were compared between groups. Results Infarcts involved the ACA in 14 cases (7.2%), MCA in 165 cases (85.1%), and PCA in 15 cases (7.7%). SICAD was diagnosed in 17 of 194 cases (8.8%), with cerebral angiography showing main findings of the string sign in 11 patients (64.7%), the pearl and string sign in 6 patients (35.3%), and pseudoaneurysm formation in 2 patients (11.7%). SICAD most frequently involved the ACA (ACA, 64.3%; MCA, 4.2%; PCA, 6.7%; P < 0.001). Conclusion SICAD was seen in 64.3% of patients with ACA infarct. The mechanisms of ACA infarction may thus differ from those of MCA and PCA infarction.

Intravenous Thrombolysis in Posterior Cerebral Artery Infarctions

Background: Approximately 5–10% of all acute ischemic strokes (AIS) occur in the territory of the posterior cerebral artery (PCA). Little is known about intravenous thrombolysis (IVT) in this infarct subgroup in terms of outcome and intracerebral hemorrhage rates. The aim of our study was to evaluate differences between supratentorial PCA infarcts and anterior circulation infarcts regarding baseline characteristics, stroke severity, outcome, safety and clinical findings, which would implicate a change in the existing thrombolysis practice in patients with PCA stroke. Methods: All patients with AIS in the supratentorial PCA territory receiving IVT between 01/2006 and 01/2010 were selected from the Erlangen Thrombolysis Database (group 1, n = 21). They were compared to all IVT patients with strokes in other supratentorial vascular territories over the same period of time (group 2, n = 398). Baseline demographic data, as well as clinical and laboratory findings were analyzed. The outcome was assessed using the modified Rankin Scale at 3 months. Results: Only serum glucose levels at baseline (110.5 ± 36.1 vs. 127.2 ± 48.2 mg/dl; p = 0.036) and the baseline National Institutes of Health Stroke Scale score (median 6.5 vs. 9; p = 0.016) were significantly lower in group 1 compared to group 2. Favorable clinical outcome (57.1 vs. 48.6%; p = 0.445) and intracerebral hemorrhage rates (4.8 vs. 4%; p = 1.000) were comparable in both groups. Conclusions: No substantial differences were found between supratentorial PCA and anterior circulation infarcts. Our data on safety and efficacy support the present common thrombolysis practice in supratentorial PCA infarct patients, though an indication for IVT should rather be based on the existence of functionally disabling deficit than merely on the National Institutes of Health Stroke Scale.

Executive dysfunction associated with stroke in the posterior cerebral artery territory

Cognitive decline following posterior cerebral artery infarction (PCAI) is associated with lesions in the occipital lobe that extend into the parahippocampus or the splenium. We investigated patterns of neuropsychological deficits, including those causing executive dysfunction, associated with isolated lesions of the occipital lobe and with extensive lesions of the occipital lobe that extended into the splenium or the posterior ventral temporal lobes including the parahippocampus and fusiform gyrus. Eleven patients with unilateral PCAI involving the cerebral cortex and one patient with an occipital hemorrhage were selected for inclusion in this study. The mean age of the patients was 68.50 ± 7.94 years and their mean level of education was 8.58 ± 4.12 years. Four patients had isolated occipital lobe lesions and eight had lesions in either the splenium or the posterior ventral temporal lobe in addition to the occipital lobe. Whereas three of four patients with isolated occipital lobe lesions had left-sided lesions, only three of the eight patients with extended occipital lesions had left-sided lesions. The patients underwent a standardized battery of neuropsychological tests. The patients with occipital injuries in addition to splenial or posterior ventral temporal lobe injuries demonstrated performance decline across diverse cognitive domains, including memory (eight of eight), visuospatial function (eight of eight), executive function (seven of eight), language-related function (four of eight) and attention (one of eight). In contrast, memory impairment (three of four patients) was the only area in which patients with isolated occipital lobe lesions demonstrated decline in performance. Our findings suggest that strokes in the territory of the posterior cerebral artery are frequently associated with executive dysfunction. Injuries involving the splenium or posterior ventral temporal lobe in addition to the occipital lobe lead to more diverse neuropsychological impairments than do isolated occipital lobe injuries alone.

The Medial Temporal Lobe Supports Conceptual Implicit Memory

The medial temporal lobe (MTL) is generally thought to be critical for explicit, but not implicit, memory. Here, we demonstrate that the perirhinal cortex (PRc), within the MTL, plays a role in conceptually-driven implicit memory. Amnesic patients with MTL lesions that converged on the left PRc exhibited deficits on two conceptual implicit tasks (i.e., exemplar generation and semantic decision). A separate functional magnetic resonance imaging (fMRI) study in healthy subjects indicated that PRc activation during encoding of words was predictive of subsequent exemplar generation. Moreover, across subjects, the magnitude of the fMRI and behavioral conceptual priming effects were directly related. Additionally, the PRc region implicated in the fMRI study was the same region of maximal lesion overlap in the patients with impaired conceptual priming. These patient and imaging results converge to suggest that the PRc plays a critical role in conceptual implicit memory, and possibly conceptual processing in general.

Potential Role of PMD‐TCD Monitoring in the Management of Hemodynamically Unstable Intracranial Stenosis

A 54-year-old woman started to loose vision 2 days prior to admission and also experienced left-sided headache, nausea, emesis, and disorientation. Magnetic resonance imaging (MRI) revealed bilateral posterior cerebral artery and cerebellar infarctions. Transcranial power motion Doppler (PMD-TCD) showed blunted flow signal in the proximal basilar artery (BA) suggestive for a high-grade stenosis also seen on magnetic resonance angiography (MRA). Dual antiplatelet therapy with aspirin and clopidogrel was started. Catheter angiography confirmed the proximal high-grade BA stenosis. After angiography, the patient experienced hypertensive crisis with severe headache. Blood pressure was lowered and headache resolved. One hour later she developed fluctuating level of consciousness and motor symptoms. PMD-TCD findings were suggestive for an intraluminal thrombus that moved from the proximal to the distal basilar artery, presumably further contributing to brain stem hypoperfusion and neurological deterioration. To achieve a compromise between lower blood pressure and maintenance of brain perfusion, hypervolemic hemodilution with intravenous dextran-40 was initiated. Patient's symptoms resolved to baseline and MRI showed no new parenchymal lesions.

Autoimmune encephalopathy presenting as a ‘posterior circulation stroke’

Antibodies to voltage gated potassium channels (VGKC) can result in a reversible form of encephalopathy [1]. Since first described, the clinical phenotype of patients with antibodies to VGKC continues to expand [2]. To our knowledge this is the first reported case of VGKC encephalopathy mimicking a stroke resulting in misdiagnosis. A 73 year old woman presented with aphasia and right upper limb weakness, 5 days post-carotid endarterectomy for an asymptomatic 90% left carotid stenosis. She had experienced atrial fibrillation (warfarin had not yet been reintroduced), hypertension, diabetes and was an ex-smoker. A CT brain done within 12 h of presentation did not show any evidence of infarction (Fig. 1). Diffusion weighted (DWI) magnetic resonance imaging (MRI) of the brain, done 2 days after presentation, demonstrated an increased signal in the left temporal lobe in the region of the hippocampus, amygdala and extending to the pulvinar region of the thalamus (Fig. 2). Restricted diffusion was seen on apparent diffusion coefficient (ADC) in the same territory, consistent with a thromboembolic infarct. A diagnosis of thromboembolic event to the left posterior cerebral artery (PCA) was made and the patient was transferred to the acute stroke unit. Warfarin was restarted and, following improvement over a month, she was transferred to a rehabilitation facility. However, after 2 weeks the patient developed visual hallucinations and was re-admitted. On arrival she had three convulsive seizures and was treated with intravenous phenytoin. A repeat MRI brain was performed (Fig. 3), 2 months from initial presentation, again showing high signal on DWI and corresponding restricted diffusion on ADC map in the same distribution as the initial imaging. Following review of the MRI imaging, the lesions were deemed to be inconsistent with a PCA infarct. Cerebrospinal fluid protein was normal and an electroencephalogram showed delta slowing in the left temporal region and intermittent sharp waves. A whole body fluorodeoxyglucose positron emission tomography (FDG–PET) scan did not show any evidence of malignancy. Voltage gated potassium channels (VGKC) levels were 1,726 pico Moles (normal \100 pM), paraneoplastic antibodies were negative. A diagnosis of autoimmune limbic encephalitis (LE) was made, as described with VGKC antibodies [1–4]. The patient was treated with methylprednisolone with an improvement in both receptive and expressive components of language. Repeat antibodies were unrecordable following initial treatment and she was discharged on oral prednisolone. She was re-admitted on two further occasions while on oral steroids. On each recurrent admission, she received methylprednisolone with a corresponding decrease of VGKC antibodies. Mycophenolate mofetil was added when a level of 2,026 pM was recorded. A wide clinical phenotype is seen in VGKC autoimmunity [2] including: Isaacs syndrome [5], Morvan H. Kearney B. Murray K. O’Rourke P. Kelly T. Lynch (&) The Dublin Neurological Institute at the Mater Misericordiae University Hospital, 57 Eccles Street, Dublin 7, Ireland e-mail: Tlynch@mater.ie URL: http://www.neurologicalinstitute.ie

Ipsilateral visual illusion after unilateral posterior cerebral artery infarction: A report of two cases

In cases of unilateral posterior cerebral artery (PCA) infarction, abnormal visual perception in the ipsilateral visual field, which is usually believed to be intact, is not met frequently and may confuse doctors during evaluation. Recently, we observed two patients who presented with contralateral hemianopsia accompanied by ipsilateral visual illusions after acute unilateral PCA infarctions. Their visual illusion was characterized by zooming in, macropsia or micropsia. These symptoms appeared to be related to deficits in size constancy. Lesions of both patients commonly involved the ipsilateral forceps major. The consistent presentation observed in these two patients suggests that dominance of size constancy can be located in the left hemisphere in some individuals.