Uncommon Association of Two Anatomical Variants of Cerebral Circulation: A Fetal-Type Posterior Cerebral Artery and Inferred Artery of Percheron, Complicated with Paramedian Thalamomesencephalic Stroke—Case Presentation and Literature Review

Abstract

Background The unilateral fetal variant of the posterior cerebral artery (FPCA) is characterized by the congenital absence of the P1 arterial segment. The artery of Percheron (AOP) is an uncommon vascular variant, in which a single dominant thalamoperforating arterial trunk arises from one P1 segment, bifurcates, and provides bilateral supply to the paramedian thalami and rostral midbrain. Case Presentation This is a retrospective case study of a 37-year-old man with multiple lifestyle risk factors (chronic marijuana and tobacco abuse), who suffered a thalamomesencephalic stroke, rapidly worsening to comatose state. After restoration of consciousness, he clinically manifested with left paramedian midbrain syndrome. Imaging demonstrated an asymmetric paramedian thalamic infarction with mesencephalon extension, patency of the basilar, vertebral arteries, and left PCA and right-sided FPCA, respectively. Left-sided thalamoperforating arterioles were not differentiated; AOP was inferred. Neither evident clinical source of embolus nor prothrombotic states were found. Mobile cardiac telemetry and transesophageal echocardiography were not available. The diagnosis was established too late for thrombolytic treatment. Anticoagulation was indicated during the acute and subacute stages, followed by low dose of antiplatelet. Discussion This uncommon cerebrovascular configuration (FPCA+AOP) might be the fourth case described in the literature. Sustained rehabilitation and abstinence from tobacco and cannabis led to favorable outcomes.

Effect of Fetal-type Posterior cerebral artery on cerebral infarction and collateral circulation

“…Thirdly, when severe stenosis or occlusion of internal carotid artery causes changes in hemodynamics, cFTP cannot quickly and effectively establish the compensation of lateral branches of the posterior circulation through the posterior communicating artery of the anterior circulation, and the compensation of lateral branches of pia meningeal anastomosis between the posterior cerebral artery, middle cerebral artery and anterior cerebral artery. Even in the presence of pFTP, it is possible that the ipsilateral internal carotid artery-posterior communication artery-posterior cerebral artery P1 segmentbasilar artery collateral circulation of pFTP is established to compensate for severe basilar artery stenosis or occlusion, further aggravating anterior circulation ischemia, thus increasing the risk and severity of anterior circulation cerebral infarction in patients [1,[11][12][13][14]. In addition, since FTP completely belongs to the internal carotid artery system, when the internal carotid artery system is completely occluded, hypoperfusion or embolus fall off, simultaneous infarction of the anterior and posterior circulation contrary to the normal situation may occur (Figs.…”

Atypical posterior circulation strokes: a case-based review of rare anatomical variations involved

“…He mentioned thar 6% of the specimens had an incomplete circle owing to the non-existence of the P1 segment of the PCA. The complete agenesis of P1 segment may be encountered bilaterally in 2% to 4% of cases [ 14 ].…”

“…Fetal posterior cerebral artery (FPCA) represents an anatomic variant of PCA, deriving directly from the ICA, without having a link with the BA [ 14 , 15 , 16 ]. The embryonic origin of the PCA was detected by angiographic studies in 11% to 46% of the general population, most commonly being found unilaterally (4–26%), while bilaterally was found in only 2–4% of cases [ 2 , 11 , 12 , 13 , 14 , 15 ].…”

“…Fetal posterior cerebral artery (FPCA) represents an anatomic variant of PCA, deriving directly from the ICA, without having a link with the BA [ 14 , 15 , 16 ]. The embryonic origin of the PCA was detected by angiographic studies in 11% to 46% of the general population, most commonly being found unilaterally (4–26%), while bilaterally was found in only 2–4% of cases [ 2 , 11 , 12 , 13 , 14 , 15 ]. An FPCA is named a full FPCA if the precommunicating arterial segment (P1) of the PCA is absent or hypoplastic, not being detected by imaging or contrast substance, and partial FPCA, when the P1 portion is present, but is smaller than the posterior communicating artery (PCoA) [ 11 , 12 , 13 , 14 ].…”

The Implications of Adverse Pharmacologic Reactions and Complex Pathogenic Mechanisms in Schizophrenia

“…The main side effects are: CBF decrease, predisposition for CSVD-ld, WMHs, endothelial dysfunction with predisposition for thromboembolism, demyelination processes and axonopathies, increased insulin resistance, diabetes, metabolic syndrome, heart attack, stroke (Hassan et al, 2004) (Figure 10). The CBF imbalance between the anterior and posterior poles, favored by the hypoperfusion of the posterior pole after acute psychotic episodes, where the hyperperfusion is located in the frontal pole, may be associated with anomalies of the circle of Willis or of artery of Percheron irrigating the thalamus (Anghelescu, 2018). In the case of hypoperfusion in arterial supply of choroid plexus, the excessive release of extracellular calcium determines calcification of choroid plexus and pineal gland.…”