Artery of Percheron Occlusion in China: A Case Report and Chinese Literature Review.

INTRODUCTION: The artery of Percheron (AOP) is a rare anatomical variant in which bilateral paramedian thalami are supplied by a single vascular branch arising from the P1 segment of the posterior cerebral artery. We present a case of AOP occlusion presenting as loss of consciousness and summarize the literature in Chinese to find the clinical characteristics. CASE REPORT: An 83-year-old woman was found unconscious for 1 day at home and was sent to the hospital the next day. Cerebral magnetic resonance imaging on day 1 of the patient showed a recent bilateral paramedian thalamic infarction. Simultaneously, magnetic resonance angiography found evident artery stenosis of the right P1 segment of the posterior cerebral artery, suggesting that the patient was diagnosed with AOP occlusion. Since the patient has missed the best time for thrombolytic therapy, anticoagulant therapy was given immediately; as the patient was then found to have pulmonary infections, antibiotic therapy was also initiated. The neurological status of this patient improved very slow. In about 2 weeks, the patient becomes more conscious but still could not speak or move. CONCLUSION: Our report suggests that unusual mood disorder and language disorder of aged patients might indicate the AOP occlusion, and cerebral imaging of magnetic resonance imaging (better with magnetic resonance angiography) should be performed to establish the diagnosis of AOP occlusion. The fast and accurate diagnosis of stroke because of AOP occlusion could best benefit the patients.

Artery of Percheron occlusion with first-pass recanalisation of the first segment of posterior cerebral artery.

This is an elderly patient who was found unconscious at home. CT of the head without contrast was unremarkable, while CT angiography of the head and neck revealed a subocclusive thrombus on the precommunicating (P1) segment of the left posterior cerebral artery (PCA). MRI brain revealed bilateral regions of diffusion restriction in the paramedian thalami and bilateral medial mesencephalon. Initial angiography confirmed the presence of a subocclusive thrombus in the P1 segment of the left PCA. Thrombectomy was performed achieving recanalisation of the left PCA and reperfusion of bilateral thalami via a visualised artery of Percheron. Postoperatively, the patient was kept on a daily dose of 325 mg of aspirin. The patient did not improve neurologically. A follow-up MRI brain showed diffusion restriction in the left occipital lobe and petechial haemorrhages in the bilateral thalami. The family eventually opted for palliative measures, and the patient expired on day 14 of admission due to acute respiratory failure from palliative extubating.

Investigation of risk factors, topographic location and stroke mechanisms of unilateral isolated and posterior cerebral ARTERY thalamic infarcts.

BACKGROUND AND PURPOSE: In this study, we aimed to examine the risk factors, topographic features and stroke mechanisms of acute ischemic unilateral infarcts of thalamus. METHODS: Patient with isolated thalamic infarct and those with posterior cerebral artery (PCA) infarction who were admitted to our hospital between January 2014 and January 2017 with acute unilateral thalamic infarction (TI) were included in this study (isolated thalamic infarction/ isolated TI; thalamic and posterior cerebral artery infarction/PCA+TI). Demographic characteristics and vascular risk factors of the patients were determined. Thalamic infarct areas were recorded topographically as anterior, posteromedial, ventrolateral, posterolateral, more than one area, and variant areas. Stroke mechanism was determined according to the criteria of "Trial of Org 10172 in Acute Stroke Treatment" (TOAST). Patients with isolated TI and PCA TI were compared according to risk factors, stroke mechanism and infarct topography. RESULTS: Forty-three patients with a mean age of 63.3 ± 14.5 years were included in the study. Twenty-eight patients (60.1%) were found to have isolated TI and the remaining 15 patients (34.9%) had PCA+TI. 32.1% of patients with isolated TI had sensory symptoms on presentation, and 60% of patients with PCA-TI had sensorimotor symptoms. The mean age, the mean score on National Institutes of Health Stroke Scale (NIHSS) and the mean frequency of atrial fibrillation were higher in PCA+TI patients than in isolated-TI patients (p: 0.04, p: 0.004, p: 0.02 respectively). 32.6% of the patients had ventrolateral, 30.2% had posteromedial involvement. Ventrolateral topography was seen in 46.7% of the PCA+TI patients, while posteromedial topography was seen in 39.3% of the isolated-TI patients. 53.6% of the isolated-TI had small vessel disease etiology, while 40% of the PCA+TI had cardioembolic etiology, and the other 40% had large artery atherosclerosis. CONCLUSION: Our study showed that the most ommon stroke mechanism in patients with thalamic infarction is the small vessel disease. Isolated TI and PCA+TI patients differ in terms of etiologic mechanism and infarct topography. Variant territorial involvement and multiple area involvements can be quite common in thalamic infarcts.

Artery of Percheron Infarct - a diagnostic and prognostic conundrum!

A 39 year old male was found unconscious at home. On arrival to the hospital the patient was profoundly somnolent but easily rousable, with no focal neurological deficits. Imaging confirmed bilateral thalamic infarcts from the occlusion of Artery of Percheron, a rare anatomic variant which is a single arterial trunk supplying the thalamus and midbrain bilaterally. Anti-platelet therapy was initiated as soon as the diagnosis was established and the patient showed a rapid remarkable recovery over the next 48 hours. He continued to improve subsequently and was at baseline functional status at 6 months. Extensive investigations for etiologies were mostly unrevealing. In such patients presenting with drowsiness/somnolence, a posterior circulation stroke should be considered if no evidence of other more common causes are found. A CT head must be followed by an MRI to confirm the diagnosis and subsequent focus should be on eliciting risk factors and careful evaluation for etiologies.

Artery of Percheron infarction: a case report.

BACKGROUND: The artery of Percheron is a rare anatomic variant of arterial supply to the paramedian thalamus and rostral midbrain, and occlusion of the artery of Percheron results in bilateral paramedian thalamic infarcts with or without midbrain involvement. Acute artery of Percheron infarcts represent 0.1 to 2% of total ischemic stroke. However, of thalamic strokes, occlusion of artery of Percheron is the cause in 4 to 35% of cases. Early diagnosis of artery of Percheron infarction can be challenging because it is infrequent and early computed tomography or magnetic resonance imaging may be negative. Thus, it can be confused with other neurological conditions such as tumors and infections. CASE PRESENTATION: This is a retrospective case study of a 56-year-old white man admitted to Umeå University Hospital and diagnosed with an artery of Percheron infarction. Medical records and the neuroradiological database were reviewed, and the diagnosis was made based on typical symptoms and radiological findings of artery of Percheron infarction. We report the case of a 56-year-old man with a history of overconsumption of alcohol who was found in his home unconscious and hypothermic. He had a Reaction Level Scale-85 score of 4. He developed ventricular fibrillation on arrival at our emergency department, and cardiopulmonary resuscitation successfully restored sinus rhythm within an estimated 2 minutes of onset. He was then put on cardiopulmonary bypass for rewarming. The initial head computed tomography performed on admission was wrongly assessed as unremarkable. Bilateral ischemia in the paramedian thalamic nuclei and pons were first documented on a follow-up computed tomography on day 24 after hospitalization. He died on day 35 after hospitalization. CONCLUSIONS: Artery of Percheron infarcts are rare. The radiological diagnosis can initially often be judged as normal and in combination with variability in the neurological symptoms it is a rather difficult condition to diagnose. For these reasons few clinicians have much experience with this type of infarct, which may delay diagnosis and initiation of appropriate treatment.

The Posterior Limb of the Internal Capsule as the Subcortical Transitional Zone of the Anterior and Posterior Circulations: Insights from Human 7T MRI.

BACKGROUND: In patients with cerebral infarction, identifying the distribution of infarction and the relevant artery is essential for ascertaining the underlying vascular pathophysiological mechanisms and preventing subsequent stroke. However, visualization of the basal perforating arteries (BPAs) has had limited success, and simultaneous viewing of background anatomical structures has only rarely been attempted in living human brains. Our study aimed at identifying the BPAs with 7T MRI and evaluating their distribution in the subcortical structures, thereby showing the clinical significance of the technique. METHODS: Twenty healthy subjects and 1 patient with cerebral infarction involving the posterior limb of the internal capsule (ICpost) and thalamus underwent 3-dimensional fast spoiled gradient-echo sequence as time-of-flight magnetic resonance angiography (MRA) at 7T with a submillimeter resolution. The MRA was modified to detect inflow signals from BPAs, while preserving the background anatomical signals. BPA stems and branches in the subcortical structures and their origins were identified on images, using partial maximum intensity projection in 3 dimensions. RESULTS: A branch of the left posterior cerebral artery (PCA) in the patient ran through both the infarcted thalamus and ICpost and was clearly the relevant artery. In 40 intact hemispheres in healthy subjects, 571 stems and 1,421 branches of BPAs were detected in the subcortical structures. No significant differences in the numbers of stems and branches were observed between the intact hemispheres. The numbers deviated even less across subjects. The distribution analysis showed that the subcortical structures of the telencephalon, such as the caudate nucleus, anterior limb of the internal capsule, and lenticular nucleus, were predominantly supplied by BPAs from the anterior circulation. In contrast, the thalamus, belonging to the diencephalon, was mostly fed by BPAs from the posterior circulation. However, compared with other subcortical structures, the ICpost, which marks the anatomical boundary between the telencephalon and the diencephalon, was supplied by BPAs with significantly more diverse origins. These BPAs originated from the internal carotid artery (23.1%), middle cerebral artery (38.5%), PCA (17.3%), and the posterior communicating artery (21.1%). CONCLUSIONS: The modified MRI method allowed the detection of the relevant BPA within the infarcted area in the stroke survivor as well as the BPAs in the subcortical structures of living human brains. Based on in vivo BPA distribution analyses, the ICpost is the transitional zone of the anterior and posterior cerebral circulations.

Endovascular parent artery occlusion of proximal posterior cerebral artery aneurysms: a report of two cases.

We report two cases of proximal posterior cerebral artery (PCA) aneurysms treated with endovascular parent artery occlusion (PAO) with coils. In both cases, selective injection from the 4 F distal access catheter clearly showed the perforating arteries arising from the PCA. Case No 1, a 49-year-old woman, was successfully treated with preservation of a paramedian artery. Case No 2, a 54-year-old woman, was treated in the same manner. The patient underwent extensive thalamic infarction after the procedure because of paramedian artery occlusion. Endovascular PAO with coils is feasible for proximal PCA aneurysms; however, preservation of perforating arteries arising from the PCA is mandatory.

The quantity-effect relationship and physiological mechanisms of different acupuncture manipulations on posterior circulation ischemia with vertigo: study protocol for a randomized controlled trial.

BACKGROUND: Recent experiments have demonstrated that different needling manipulations may induce variable effects via diverse physiological mechanisms. A previous study indicated that needling at Fengchi (GB 20) improved cerebral blood flow in patients with vertigo induced by posterior circulation ischemia (PCI). In this study, we aim to explore the quantity-effect relationship and the physiological mechanisms underlying different acupuncture manipulations in PCI patients with vertigo. METHODS/DESIGN: We propose a pragmatic randomized and controlled trial. All participants, outcome assessors, and statisticians will be blinded. A total of 144 eligible participants will be randomized into one of four treatment groups receiving acupuncture at Fengchi (GB 20) with different one-minute manipulation parameters. Group 1 will receive twirling at a frequency of 60 times per minute toward the contralateral outer canthus at a depth of 0.5 to 0.8 cun. Group 2 will receive twirling at a frequency of 60 times per minute toward the Adam's apple at a depth of 0.5 to 0.8 cun. Group 3 will receive twirling at a frequency of 120 times per minute toward the contralateral outer canthus at a depth of 0.5 to 0.8 cun. Group 4 will receive twirling at a frequency of120 times per minute toward the Adam's apple at a depth of 0.5 to 0.8 cun. Additional points will be added based on individualized pattern diagnoses. The participants will receive 14 acupuncture sessions over 3 to 4 weeks. The subjects will be assessed at two time points: baseline and post-treatment. The primary outcome measurements will include subjective measurements (Vertebrobasilar System Ischemic Neurological Impairment Scale, UCLA Dizziness Questionnaire, Activities of Daily Living Scale, and Psychological and Social Adaptation Scale) and objective measurements (Transcranial Doppler, carotid ultrasonography and changes in cerebral oxygenation) to reduce bias arising from the placebo effect. We will use metabolomics to investigate the mechanisms underlying the different manipulation parameters. DISCUSSION: This trial aims to explore the quantity-effect relationship between different acupuncture manipulations and their clinical effects. The results from this study may help explain the contradictory results found in acupuncture studies that practice different manipulations. TRIAL REGISTRATION: Chinese Clinical Trial Registry: ChiCTR-RTRCC-12002675 (registered on 14 November 2012).

Onyx embolization of an avulsed thalamoperforator following endoscopic colloid cyst and lamina terminalis fenestration.

A patient presented with headaches and was found to have a colloid cyst in the third ventricle and ventriculomegaly. The patient underwent endoscopic colloid cyst resection and third ventriculostomy without incidence. Prior to emergence, a blown right pupil was acutely noted, and bright red blood emanated from the ventricular drain that was routinely placed in the endoscopy tract at the conclusion of the procedure. CTangiography demonstrated active extravasation from the pre-pontine cistern into the third ventricle and subarachnoid space. Emergency DSA confirmed active extravasation from an avulsed thalamoperforator arising from the proximal right P1 posterior cerebral artery, which was immediately embolized without incident.

The artery of Percheron: an anatomic study with potential neurosurgical and neuroendovascular importance.

BACKGROUND: One variant branch of the P1 segment of the posterior cerebral artery (PCA) is the artery of Percheron (AOP). This unilateral trunk supplies thalami and potentially mesencephalic structures. As studies of this vessel are scant in the literature and damage to this artery can have catastrophic results, the authors performed this study to better elucidate its morphology. MATERIALS AND METHODS: Twenty-five adult latex-injected cadaveric heads underwent brain removal and microdissection with specific attention to the presence of the AOP. When identified, measurements were made and observations given to the origin and course of this vessel. A case illustration is also presented that demonstrates bilateral thalamic and midbrain infarctions most likely due to thrombosis of the AOP. RESULTS: An AOP was identified in three specimens (12%)-2 right and 1 left side (1 male and 2 female specimens) and arose, on average, 8 mm lateral to the basilar artery bifurcation. The average diameter was 2.1 mm, and the length between the origin and brain penetration had a mean distance of 1.5 cm. In all specimens, the AOP had a coiled appearance, especially in its proximal extraparenchymal segment. The contralateral P1 segment of the PCA was not absent or hypoplastic in any of the three specimens. All arteries supplied small branches to the ipsilateral and contralateral thalami and midbrain. CONCLUSIONS: Knowledge of the AOP may be important during surgical or neuroendovascular approaches to the basilar bifurcation or during interpretation of imaging, especially in patients presenting with bilateral thalamic and midbrain infarctions.

Skew deviation as the initial manifestation of left paramedian thalamic infarction.

We describe a 73-year-old man who developed diplopia as the initial manifestation of a left thalamic infarction. By the time he reached the emergency department, clouded consciousness precluded localization of the lesion. Results of brain MRI were initially interpreted as negative. Ophthalmologic examination several hours later disclosed a small vertical ocular misalignment attributed to skew deviation. This finding led to careful scrutiny of the upper brainstem on MRI. Comparison of the diffusion, apparent diffusion coefficient, and exponential apparent diffusion coefficient MRI studies allowed a diagnosis of subtle left thalamic infarction. The recognition of skew deviation in this setting is important because it may be the most specific indicator of a brainstem lesion.