Psychotic Disorder after Left Posterior Cerebral Artery Stroke-An Atypical Event.

INTRODUCTION: Stroke survivors usually present physical and neuropsychiatric complications. Post-stroke psychosis (PSPsy) is a particularly neglected sequel despite its disruptive nature. OBJECTIVES: To present a case of early emerging neuropsychiatric symptoms following a left posterior cerebral artery (PCA) stroke. To review and discuss PSPsy clinical manifestations, pathophysiology, and clinical outcomes. CLINICAL CASE: A previously autonomous 68-year-old woman with vascular risk factors and depressive disorder presented to the emergency department with a 5-day history of disorientation, motor aphasia, and right hypoesthesia. Computer tomography revealed a left PCA stroke. She was started on acetylsalicylic acid and rosuvastatin and discharged the next day. Afterward, the patient developed a depressive mood, emotional lability, periods of confusion, delusions of persecution, guilt and unworthiness, auditory hallucinations, and suicide ideation. She was admitted to a psychiatric hospital and started on risperidone with a good response, being discharged after 15 days with the resolution of psychiatric symptoms. CONCLUSIONS: PSPsy is more common after right hemisphere lesions and usually develops after some months. Nevertheless, our patient presented PSPsy following an ischemic event of the left PCA, with neuropsychiatric symptomatology dominating the clinic since the beginning. The involvement of the retrosplenial cortex or its connections was likely important for this atypical presentation. Due to the lack of guidelines on approaching PSPsy, most patients are treated with the same strategies used for non-stroke patients. A better comprehension of the anatomical basis underlining the symptomatology in these patients could deepen the understanding of psychosis and psychotic disorders.

Presenting Symptoms and Imaging Features of Posterior Cerebral Artery Stroke Causing Homonymous Hemianopia.

BACKGROUND: Posterior cerebral artery (PCA) stroke is a common cause of homonymous hemianopia and other neurologic deficits associated with more proximal ischemia in the vertebrobasilar circuit. Localization of the process can be challenging unless the symptom complex is well recognized, yet early diagnosis is critical to forestall dangerous driving and repeated stroke. We undertook this study to provide additional detail about the presenting symptoms and signs and their correlation with imaging abnormalities and stroke etiology. METHODS: Retrospective study of medical records of patients presenting to a single tertiary care academic center between 2009 and 2020 with homonymous hemianopia from PCA stroke. We excerpted data on symptoms, visual and neurologic signs, incident medical procedures and diagnoses, and imaging features. We determined stroke etiology using the Causative Classification Stroke system. RESULTS: In a cohort of 85 patients, 90% of strokes occurred without preceding symptoms. But in retrospect, 10% of strokes did have warning symptoms. In 20% of patients, strokes followed within 72 hours of a medical or surgical procedure or newly identified medical condition. In the subgroups of patients whose records contained a description of visual symptoms, 87% reported the visual sensation as negative, and 66% realized that it was located in a hemifield in both eyes. Concurrent nonvisual symptoms were present in 43% of patients, consisting commonly of numbness, tingling, and new headache. Infarction located outside the visual cortex affected primarily the temporal lobe, thalamus, and cerebellum, reflecting the widespread nature of ischemia. Nonvisual clinical manifestations and arterial cutoffs on imaging were associated with thalamic infarction, but the clinical features and location of the infarction did not correlate with the etiology of the stroke. CONCLUSIONS: In this cohort, clinical localization of the stroke was aided by the fact that many patients could lateralize their visual symptoms and had nonvisual symptoms suggestive of ischemia affecting the proximal vertebrobasilar circuit. Numbness and tingling were strongly linked to concurrent thalamic infarction. Clinical features and infarct location were not associated with the etiology of the stroke.

Demographics, Risk Factors, and Etiology of Posterior Cerebral Artery Stroke Causing Homonymous Hemianopia.

BACKGROUND: Posterior cerebral artery (PCA) strokes account for up to 10% of all ischemic strokes, often presenting with homonymous hemianopia. The proportion of these strokes attributed to various etiologies varies widely in previously published studies, owing largely to differing patient populations, definitions of stroke pathogenesis, and vascular territories involved. The Causative Classification System (CCS), an automated version of the Stop Stroke Study (SSS) Trial of Org 10,172 in Acute Stroke Treatment (TOAST) system, allows for a more rigorous assignment of stroke etiology. METHODS: We excerpted clinical and imaging data on 85 patients who had PCA stroke with homonymous hemianopia examined at the University of Michigan. We compared the stroke risk factor profile of our PCA cohort with that of 135 patients with stroke in the distribution of the internal carotid artery (ICA) and middle cerebral artery (MCA) in an unpublished University of Michigan registry. We applied the CCS web-based calculator to our PCA cohort to determine stroke etiology. RESULTS: In our PCA cohort, 80.0% had at least 2 conventional stroke risk factors and 30.6% had 4 risk factors, most commonly systemic hypertension. The risk factor profile of our PCA cohort resembled that of our ICA/MCA cohort except that the mean age of our PCA cohort was more than a decade younger and had a significantly lower frequency of atrial fibrillation (AF) than our ICA/MCA cohort. In nearly half of the patients with AF in our PCA cohort, AF was diagnosed after the stroke. Among stroke etiologies in our PCA cohort, 40.0% were of undetermined cause, 30.6% were from cardioaortic embolism, 17.6% were from other determined causes, and only 11.8% were from supra-aortic large artery atherosclerosis. Strokes after endovascular or surgical interventions were prominent among other determined causes. CONCLUSIONS: Most patients in our PCA cohort had multiple conventional stroke risk factors, a finding not previously documented. Mean age at stroke onset and AF frequency were lower than in our ICA/MCA cohort, in agreement with previous studies. As some other studies have found, nearly 1/3 of strokes were attributed to cardioaortic embolism. Within that group, AF was often a poststroke diagnosis, a finding not previously highlighted. Compared with earlier studies, a relatively high portion of strokes were of undetermined etiology and of other determined etiologies, including stroke after endovascular or surgical interventions. Supra-aortic large artery atherosclerosis was a relatively uncommon explanation for stroke.

Occipito-temporal infarction manifesting as isolated visual perceptual abnormalities: A rare case of posterior cerebral artery stroke.

Ischemic stroke in the Posterior Cerebral Artery (PCA) territory is an uncommon entity. Majority present with visual field defects while isolated visual perceptual abnormalities are an exceptional manifestation. About 60 year old hypertensive patient presented with vague symptoms of blurring of vision and palinopsia. Defective color vision was recorded in superior quadrants. Perimetry revealed bilateral congruous left superior quadrantanopia. Magnetic Resonance Imaging (MRI) disclosed right PCA infarct involving occipito-temporal region. This case highlights a rare presentation of PCA stroke with palinopsia and cerebral dyschromatopsia. Perimetric examination coupled with urgent neuroimaging helps the clinician in prompt diagnosis of neurological event causing unexplained visual phenomena.

Correlation of Macular Sparing and Homonymous Paracentral Scotomas With MRI Lesions in Posterior Cerebral Artery Infarction.

BACKGROUND: The concepts of the representation of visual field in primary visual cortex are based on studies of war wounds and correlations with brain imaging in small cohorts. Because of the difficulty of judging brain lesion extent and the small number of studied patients, there is lingering controversy as to whether the central 15° of visual field are mapped onto the posterior 25% of primary visual cortex or onto a larger area. To improve the delineation of MRI lesion extent, we have studied only patients with posterior cerebral artery (PCA) ischemic strokes. METHODS: We accrued a cohort of 92 patients with PCA strokes from an electronic medical records search between 2009 and 2020 at a single tertiary care academic institution. Patients had reliable static perimetry demonstrating homonymous hemianopias and high-definition reviewable brain imaging. We divided the primary visual cortex on the MRI T1 sagittal sequence into 8 equal segments in right and left cerebral hemispheres and located lesions according to the segments they occupied. We correlated lesion locations with 3 visual field defects (VFDs): macular-sparing homonymous quadrantanopias, macular-splitting homonymous quadrantanopias, and homonymous paracentral scotomas. RESULTS: Among 25 cases with macular sparing, 13 had lesion-sparing confined to the posterior 25% of visual cortex. Among 6 cases with homonymous paracentral scotomas, 2 had lesions confined to the posterior 25% of visual cortex. Macular-splitting quadrantanopia did not occur in any patients with lesions confined to the posterior 25% of visual cortex, but did occur in 3 patients with lesions confined to the posterior 50% of visual cortex. These phenomena would not be expected if the central 15° of visual field were mapped onto a region extending beyond the posterior 25% of visual cortex. In patients with PCA strokes that involved the retrogeniculate visual pathway proximal to visual cortex, the visual cortex lesions were often less extensive than predicted by the VFDs, perhaps because of widespread damage to axons before they reached their destination in visual cortex. CONCLUSIONS: These results support the concept that the central 15° of the visual field are represented in the posterior 25% of visual cortex. Although this study contributes a larger cohort of patients with better-defined lesion borders than in past reports, its conclusions must be tempered by the variability of patient attention during visual field testing, the subjectivity in the interpretation of the defect patterns, and the difficulty in judging MRI lesion extent even on diffusion-weighted and precontrast T1 sagittal sequences.

The amnestic syndrome of posterior cerebral artery infarction.

BACKGROUND AND PURPOSE: Little is known about the character and underlying lesions of ischaemic amnesia. Episodic memory functions and brain lesions were therefore studied in 84 patients with acute ischaemic infarcts in the supply territory of the posterior cerebral artery. The aim was also to learn how the neural memory systems are organized. METHODS: Standard neuropsychological tests were used to assess verbal and figural memory. Patients were split into memory-impaired and memory-intact groups. Lesions were demarcated, normalized and anatomically labelled, using standard mapping procedures. RESULTS: Of the 84 patients more than 80% had an amnestic syndrome, mostly with combined memory impairment, less often with figural or verbal memory impairment. Amnesia in subjects with left hemispheric lesions was more frequent and more severe, with significantly lower scores on the verbal memory test. Normal performance or figural amnesia were prevalent after right hemispheric lesions. However, no amnesia subtype was strictly tied to left- or right-sided brain damage. Hippocampal and thalamic lesions were common, but 30% of lesions were extrahippocampal located in the ventral occipito-temporal cortex and long occipital white matter tracts. Most amnestic patients lacked awareness for their memory impairment. CONCLUSIONS: Memory impairment is a key clinical manifestation of acute posterior cerebral artery stroke. Amnesia is more frequent and more severe after left stroke, suggesting a left hemisphere dominance of the two memory systems. Domain specific memory appears not to be strictly lateralized, since deficits in verbal and figural memory were found after lesions of both sides. Extrahippocampal lesions may also cause memory impairment.

Infarto cerebeloso bilateral agudo en territorio de la arteria cerebelosa posterior inferior: reporte de caso / Acute bilateral cerebellar infarction in territory of the posterior inferior cerebellar artery: a case report

Antecedentes: Los infartos cerebelosos suponen una entidad rara con una incidencia baja del total de ictus isquémicos. El territorio más prevalente de los infartos cerebelosos son los de la arteria cerebelosa posterior inferior (PICA). Cuando los infartos se limitan al cerebelo, los pacientes típicamente experimentan síntomas no específicos, esto hace considerar otros diagnósticos de forma errónea. Descripción del caso clínico: paciente femenina de 54 años, con antecedente de hipertensión arterial, quien presentaba cefalea insidiosa y progresiva acompañado de vértigo, alteración en la marcha y deterioro progresivo del estado de conciencia. Se realizó imagen de Resonancia Magnética Cerebral (IRM), la cual reveló zonas hiper intensas bilaterales en región cerebelosa que delimitaban territorio vascular de la arteria cerebelosa posterior inferior además dilatación moderada del sistema ventricular. Fue intervenida quirúrgicamente, realizándose craniectomía suboccipital descompresiva; posterior a la cirugía presentó mejoría clínica. Conclusiones: El ictus isquémico cerebeloso bilateral es una forma infrecuente de ictus y su presentación clínica es muy diversa. El desarrollo de las neuroimágenes, juegan un papel importante para ayudar a los médicos a seleccionar el tratamiento adecuado. Alrededor de la mitad de los pacientes con infartos cerebelosos que presentan deterioro neurológico progresivo y son tratados con craniectomía suboccipital descompresiva tienen buenos resultados. El pilar fundamental de este caso fue el hacer un diagnóstico temprano de esta entidad, ya que permitió prevenir las posibles complicaciones graves asociadas al infarto cerebeloso, las cuales ocurren durante la primera semana del ictus y, por lo tanto, asegurar un pronóstico favorable para el paciente...(AU)

Mechanisms of Stroke in Patients with Fetal Posterior Cerebral Artery.

OBJECTIVES: The fetal-type posterior cerebral artery (FTP) is a normal variation of the posterior cerebral artery (PCA), occurring in 3-36% of general population. The effects of the FTP in stroke mechanisms remain debatable. We aimed to investigate the differences in stroke mechanisms and lesion locations between patients with and without FTP. METHODS: A total of 394 patients with PCA territory stroke were divided into those with PCA ischemic stroke associated with ipsilateral FTP and those without. The baseline characteristics, vascular risk factors, infarct pattern, stroke location, stroke etiology, and the diameter of P1 in patients without FTP or posterior communicating artery (PcoA) in patients with FTP were investigated. RESULTS: Among the 394 patients, 52 (13.2%) PCA stroke patients with ipsilateral FTP were enrolled. Patients with FTP, in comparison with those without, had a higher frequency of deep infarct pattern (69.2% vs. 47.1%, P=0.012), small vessel occlusion (51.9% vs. 28.9%, P=0.009), ventrolateral thalamic involvement (65.4% vs. 49.1%, P=0.042), and a lower frequency of cardiac embolism (9.6% vs. 24.0%, P=0.009). The diameter of P1 in patients without FTP was larger than that of PcoA in patients with FTP (2.1 ± 0.3 mm vs. 1.6 ± 0.2 mm, P <0.001). CONCLUSIONS: The stroke mechanisms, infarct pattern, and the location of the stroke were different between patients with and without FTP. PCA stroke patients with FTP more often had small vessel occlusion and ventrolateral thalamic involvement. These results are probably associated with difference in the hemodynamic status according to the presence of FTP.

A clinical study of 288 patients with anterior cerebral artery infarction.

OBJECTIVE: Acute ischemic stroke in the territory of anterior cerebral artery (ACA) is uncommon. Therefore, large population studies evaluating ACA infarction are scarce. We sought to evaluate epidemiological and etiological characteristics of ACA infarction compared to other territorial infarctions. METHODS: We analyzed a prospectively collected stroke registry of all acute ischemic stroke patients for 19 years at two tertiary hospitals. We included patients with acute ischemic stroke caused by large vessel stenosis or occlusion including ACA, middle cerebral artery (MCA), posterior cerebral artery (PCA), and vertebrobasilar artery (VBA). RESULTS: A total of 4171 patients were enrolled. Patients with ACA infarction (N = 288) were significantly older with more females than those with MCA, PCA, or VBA infarction. There were more patients with history of prior ischemic stroke in the ACA infarction group than in other groups. The etiology of the ACA infarction was similar to those of the MCA, PCA and also the total population (66.7-71.8% of LAA and 17.9-20.9% of CE). When patients had prior ischemic stroke history, ACA infarction was more likely to be caused by LAA than MCA or PCA infarction (OR = 6.2, 95% CI 2.0-19.2, p = 0.002 and OR = 4.0, 95% CI 1.1-14.6, p = 0.038, respectively). CONCLUSIONS: Patients with ACA infarction had significantly more prior ischemic stroke than those with MCA, PCA, or VBA infarction. The etiology of ACA infarction in patients with prior ischemic stroke showed significantly more LAA than that of MCA or PCA infarction.

Lesion topography of posterior cerebral artery infarcts.

This study analyzed the topography of acute ischemic stroke in the posterior cerebral artery (PCA) territory. We studied 84 patients with unilateral ischemic PCA stroke. Patients were classified according to lesion levels as cortico-subcortical (superficial), combined (cortical and mesodiencephalic) or isolated thalamic. To receive a lesion map, data from acute MR and CT imaging were normalized and labelled automatically by mapping to stereotaxic anatomical atlases. Cortical lesions accounted for 41.7%, combined for 36.9%, and isolated thalamic lesions for 21.4%. The maximum overlay of ischemia and, thus, highest occurrence of PCA ischemic stroke was found in the ventral and medial occipito-temporal cortex and adjacent white matter association tracts. Dorsal and peripheral segments of the occipito-temporo-parietal region were only rarely lesioned. This configuration was similar in both hemispheres. Consistent with this lesion pattern, visual field defects (VFD) were the most frequent signs, followed by sensorimotor signs, dizziness and sopor, cognitive and oculomotor deficits, and ataxia. The three vascular subgroups differed not only by their anatomical lesion profile and lesion load, but also by their clinical manifestation; although patients with combined and thalamic lesions were sigificantly younger, they were more disabled than participants with cortical lesions. VFD were only found in cortical and combined, and oculomotor deficits only in mesodiencephalic lesions. White matter lesions were common in the cortico-subcortical and the combined group. Basal occipito-temporal and calcarine regions, and neighbouring white matter tracts have the highest risk of ischemia in acute PCA stroke.

Early Brain Imaging Shows Increased Severity of Acute Ischemic Strokes With Large Vessel Occlusion in COVID-19 Patients.

BACKGROUND AND PURPOSE: Reports are emerging regarding the association of acute ischemic strokes with large vessel occlusion and coronavirus disease 2019 (COVID-19). While a higher severity of these patients could be expected from the addition of both respiratory and neurological injury, COVID-19 patients with strokes can present with mild or none respiratory symptoms. We aimed to compare anterior circulation large vessel occlusion strokes severity between patients with and without COVID-19. METHODS: We performed a comparative cohort study between patients with COVID-19 who had anterior circulation large vessel occlusion and early brain imaging within 3 hours from onset, in our institution during the 6 first weeks of the COVID-19 outbreak and a control group admitted during the same calendar period in 2019. RESULTS: Twelve COVID-19 patients with anterior circulation large vessel occlusion and early brain imaging were included during the study period and compared with 34 control patients with anterior circulation large vessel occlusion and early brain imaging in 2019. Patients in the COVID-19 group were younger (P=0.032) and had a history of diabetes mellitus more frequently (P=0.039). Patients did not significantly differ on initial National Institutes of Health Stroke Scale nor time from onset to imaging (P=0.18 and P=0.6, respectively). Patients with COVID-19 had more severe strokes than patients without COVID-19, with a significantly lower clot burden score (median: 6.5 versus 8, P=0.016), higher rate of multivessel occlusion (50% versus 8.8%, P=0.005), lower DWI-ASPECTS (Diffusion-Weighted Imaging-Alberta Stroke Program Early CT Scores; median: 5 versus 8, P=0.006), and higher infarct core volume (median: 58 versus 6 mL, P=0.004). Successful recanalization rate was similar in both groups (P=0.767). In-hospital mortality was higher in the COVID-19 patients' group (41.7% versus 11.8%, P=0.025). CONCLUSIONS: Early brain imaging showed higher severity large vessel occlusion strokes in patients with COVID-19. Given the massive number of infected patients, concerns should be raised about the coming neurovascular impact of the pandemic worldwide.

Bilateral posterior cerebral artery territory infarction in a SARS-Cov-2 infected patient: discussion about an unusual case.

In time of SARS-Cov2 pandemic, neurologists need to be vigilant for cerebrovascular complications of Covid-19. We present a case of bilateral occipito-temporal infarction revealed by a sudden cortical blindness with haemorrhagic transformation after intravenous thrombolysis in a diabetic patient infected by Covid-19. Differential diagnoses are discussed in front of this unusual presentation and evolution.

Alien limb phenomenon following posterior cerebral artery stroke: a distinct clinical entity.

Alien limb syndrome following stroke within the territory of the posterior cerebral artery is exceedingly rare. A right-handed female experienced left homonymous hemianopia, visuospatial neglect, and proprioceptive loss of her left hemi-body. She experienced unintended, involuntary movements of her left arm and hand, which interfered with and disturbed motor actions of daily life performed with her right upper limb. There was no denial of ownership, but she interpreted movements of her left upper limb to be annoying, out of her will and unwanted. The alien limb phenomenon improved in parallel with improvement of proprioceptive loss over a 12-week of in-patient rehabilitation. A recently proposed theoretical concept of the alien limb phenomenon after posterior artery stroke is discussed.

Diagnostic value of eye movement and vestibular function tests in patients with posterior circulation infarction.

OBJECTIVE: To evaluate the diagnostic value of eye movements and vestibular function tests in PCI patients. METHODS: Thirty-eight PCI patients and 31 patients with unilateral vestibular neuritis (UVN) were enrolled and underwent eye movement tests and vestibular function tests (spontaneous nystagmus [SN], head-shaking nystagmus [HSN]). RESULTS: The rates of eye movement abnormality were 78.9% and 41.9% in PCI and UVN patients, respectively. The positive rate of SN and HSN were, respectively, 41.2% and 43.8% in cerebellar infarction patients, 33.3% and 66.7% in medullary infarction patients, and 100.0% and 86.2% in UVN patients. The horizontal direction of SN and HSN coincided with the affected side in cerebellar infarction patients, and the healthy side in UVN patients, which coincided with the healthy side and the affected side, respectively in medullary infarction patients. The horizontal direction of HSN was bidirectional nystagmus in 16.0% (4/25) of UVN patients. CONCLUSIONS AND SIGNIFICANCE: Eye movement and vestibular function tests contribute to the early diagnosis of PCI. The horizontal direction of SN and HSN are consistently toward the affected side in cerebellar infarction patients and the healthy side in UVN patients, in contrast to medullary infarction patients, and deserve further investigations.

Percheron Infarction: Is It Just a Rare Cerebrovascular Variant or a Forewarning of Severe Multiple Posterior Circulation Infarcts.

Percheron infarction, arising from occlusion of the Artery of Percheron, is few, which can result in bilateral thalamic and mesencephalic infarctions. We herein showcase a confirmed case of the Percheron infarction at the admission day, in which the patient advanced into severe multiple posterior circulation infarcts, along with petechial hemorrhage within the infarcts, even given the right therapy without delay. It reminds us that whether we could or should take this special infarction as a forewarning of more harmful infarcts getting in the way, or at least a precaution of poor vessel condition.

A Posterior Circulation Ischemia Risk Score System to Assist the Diagnosis of Dizziness.

BACKGROUND: We aimed to establish a risk score system without radio-image examination, which could help clinicians to differentiate patients with vertigo and posterior circulation ischemia (PCI) rapidly from the other dizzy patients. METHODS: We analyzed 304 patients with vertigo (50% PCI). The attributes with more significant contributions were selected as the risk factors for the PCI risk score system, and every one of them was assigned a value according to their respective odds ratio values. We also compared the respective receiver operating characteristic curves of the 3 diagnostic methods (PCI score system, ABCD2, and Essen score systems) to evaluate their prediction effectiveness. RESULTS: Nine risk factors were ultimately selected for PCI score system, including high blood pressure (1'), diabetes mellitus (1'), ischemic stroke (1'), rotating and rocking (-1'), difficulty in speech (5'), tinnitus (-5'), limb and sensory deficit (5'), gait ataxia (1'), and limb ataxia (5'). According to their respective PCI risk scores, the patients were divided into 3 subgroups: low risk (≤0', risk <37.4%), medium risk (1'-5'), and high risk (≥6', risk >95.0%). When 0' was selected as a cutoff point for differentiating the patients with PCI from patients without PCI, the sensitivity was 94.1%, with a specificity of 41.4%. The areas under the receiver operator curve value of PCI score system was .82 (P = .000), much higher than the areas under the receiver operator curve value of ABCD2 (.69, P = .000) and that of the Essen system (.67, P = .000) CONCLUSION: The PCI score system could help clinicians to differentiate patients with vertigo and PCI rapidly from the other dizzy patients.

High Incidence of Atrial Fibrillation After Embolic Stroke of Undetermined Source in Posterior Cerebral Artery Territory.

BACKGROUND: Subclinical atrial fibrillation is one possible cause of embolic stroke of undetermined source (ESUS). It remains to be elucidated if a specific infarction site has a predictive value for detecting subclinical atrial fibrillation. We aimed to investigate the predictive value of infarction site in patients with ESUS for the detection of atrial tachyarrhythmia (AT) using an insertable cardiac monitor. METHODS AND RESULTS: Consecutive 146 patients (84 men; aged 62±12 years) underwent insertable cardiac monitor implantation after diagnosis of ESUS. The detection of AT >30 seconds was evaluated. The ESUS infarction sites were categorized into internal carotid artery and vertebral artery (VA) territories, with ophthalmic artery, anterior cerebral artery, and middle cerebral artery as internal carotid artery subterritories, and posterior cerebral artery and other vertebrobasilar arteries as VA subterritories. During a median follow-up of 387 days, AT was detected in 33 patients (23%). Subclinical AT detection was significantly more frequent after VA territorial infarction opposed to internal carotid artery infarction (20/57 [35%] versus 13/89 [15%]; P=0.0039). Kaplan-Meier analysis demonstrated a significantly higher AT detection rate after VA infarction (log-rank, P=0.0076). Regression analysis revealed that VA territorial infarction, and particularly posterior cerebral artery area infarction, was an independent predictor of AT detection. CONCLUSIONS: Patients with ESUS in the posterior cerebral artery territory had a higher rate of subclinical AT detection than those with other infarct localizations. Our data suggest that the possible usefulness of ESUS site to identify candidates for direct oral anticoagulation should be confirmed in future research.

Reading on the right when there's nothing left? Probabilistic tractography reveals hemispheric asymmetry in pure alexia.

We present a patient with reading inexpertise and right hemianopia following left posterior cerebral artery (PCA) stroke. We examine the extent of disruption to reading performance and the extent of white matter tract damage relative to a patient with more limited PCA infarction and isolated right hemianopia. We show white matter disconnection of the temporal occipital fusiform cortex in our pure alexia patient. Connectivity-based laterality indices revealed right hemisphere laterality in the alexia patient; this was not associated with improved reading function. We speculate that the degree of premorbid laterality may be a critical factor affecting the extent of reading dysfunction in alexia.