Artery of Percheron infarction presenting as nuclear third nerve palsy and transient loss of consciousness: a case report

Abstract

Background: Thalamic blood supply consists of four major vascular territories. Out of them paramedian arteries supply ipsilateral paramedian thalami and occasionally rostral mid brain. Rarely both paramedian arteries arise from a common trunk that arise from P1 segment of one sided posterior cerebral artery (PCA). This is usually due to hypoplastic or absent other P1 and this common trunk is termed Artery of Percheron (AOP). Its prevalence is in the range of 7-11% among the general population and AOP infarcts account in an average of 0.4-0.5% of ischemic strokes. Clinical presentation of AOP infarction is characterized by impaired arousal and memory, language impairment and vertical gaze palsy. It also can present with cerebellar signs, hemi paresis and hemi sensory loss. We herein present a case of AOP infarction presenting as transient loss of consciousness and nuclear third nerve palsy. Case presentation: A 51 year old previously healthy male, was brought to us, with a Glasgow coma scale (GCS) of 7/15. GCS improved to 11/15 by the next day, however he had a persisting expressive aphasia. Right sided nuclear third nerve palsy was apparent with the improvement of GCS. He did not have pyramidal or cerebellar signs. Thrombolysis was not offered as the therapeutic window was exceeded by the time of diagnosis. Diagnosis was made using magnetic resonance imaging (MRI) that was done after the initial normal non-contrast computer tomography (NCCT) brain. He was enrolled in stroke rehabilitation. Aspirin and atorvastatin was started for the secondary prevention of stroke. He achieved independency of advanced daily living by 1 month, however could not achieve full recovery to be employed as a taxi driver. Conclusions: Because of the rarity and varied clinical presentation with altered levels of consciousness, AOP infarcts are easily overlooked as a stroke leading to delayed diagnosis. Timely diagnosis can prevent unnecessary investigations and the patient will be benefitted by early revascularization. As it is seldom reported, case reports remain a valuable source of improving awareness among physicians about this clinical entity.

Percheron-like artery infarction after transsphenoidal surgery: illustrative case

“…While isolated AOP infarction is seen in less than 1% of all strokes, 3,4 the typical findings in patients with bilateral paramedian thalamic infarctions are described by the triad of altered mental status, vertical gaze palsy, and memory impairment. 3 The present case is exceptional with regard to the following points.…”

Artery of Percheron Infarction: A Case Report of Bilateral Thalamic Stroke Presenting with Acute Encephalopathy

“…Classic findings of this condition include impaired arousal, memory, or language impairment, and occasionally an ocular movement disorder [ 3 , 4 ]. AOP infarctions are rarely associated with pyramidal symptoms, and initial noncontrast CT head imaging can be normal and misleading [ 5 ].…”

“…These varied clinical presentations without localizing findings and the rarity of this anatomic variant often cause significant delay in obtaining MR brain imaging and ultimately identifying an accurate diagnosis [ 5 ]. Figure 1 demonstrates four variations in the arterial supply of the thalamic circulation, and Table 1 provides a summarized description of each thalamic arterial supply variant.…”

“…Variant III (paramedian territory): several small perforating branches arise from one arterial supply that bridges the P1 segments of both posterior communication arteries. Vascular compromise leads to hypersomnolence if the lesion is bilateral in addition to symptoms such as memory impairment, difficulty in learning, and language deficits [ 5 ].…”

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

“…Four variants of neurovascular supply to the midbrain and thalamus were described by Gérard Percheron in 1973. The artery of Percheron (AOP) represents a congenital malformation of the paramedian arterial supply, in which an artery, emergent from the P1 segment, endows, by itself, through bifurcation both paramedian thalamus and, in some cases, the rostral mesencephalon [ 18 , 19 , 20 ].…”