Percheron artery infarction in the differential diagnosis of acute confusional state with normal initial brain MRI

Bilateral anterior thalamic symmetrical infarction: a case study

BACKGROUND

Bilateral anterior thalamic symmetrical infarction is very rarely observed in clinical practice and has rarely been reported in the literature. In this paper we introduce a patient with bilateral anterior thalamic symmetrical infarction and discuss his symptoms, treatment process, and follow-up visit results, as well as the potential pathological mechanisms of the disease.

CASE PRESENTATION

A 71-year-old male had a sudden cognitive decline four days prior to medical consultation. The patient's brain MRI showed symmetrical high signals in the anterior part of both sides of the thalamus. The patient's head MRV and immunological tests were normal, and we considered that this patient had a rare case of bilateral anterior thalamic infarction. After 10 days of anti-platelet aggregation that lowered blood lipids and improved circulation, the patient's symptoms significantly abated. Two years later, we found through telephone follow-up that the patient's symptoms had not relapsed substantially and that he was able to perform self-care, having only continued to suffer a slight decline in short-term memory.

CONCLUSION

For patients with bilateral prethalamic lesions who have only acute cognitive impairment, if the lesions conform to the blood supply area of both thalamic nodular arteries and DWI shows a high signal, the diagnosis of acute cerebral infarction should be considered, and the standard treatment plan for cerebral infarction should be given as soon as possible.

Bilateral Thalamic Infarction Secondary to Thrombosis of Artery of Percheron

The artery of Percheron (AOP) is a rare anatomical variation emerging from the posterior circulation and supplies both thalami in the brain. As per the literature, the AOP infarction constitutes less than 2% of all stroke cases. AOP infarctions are usually caused by a combination of risk factors and a predisposing vascular territory. The areas most affected by AOP are the paramedian thalami with or without the involvement of the midbrain. AOP can be challenging as it is infrequent and mostly can be missed on the initial scans. We present a 58-year-old previously healthy male known to have hypertension with poor follow-up who presented with dysarthria and facial weakness, which he felt after waking up from sleep. After the initial physical examination and investigations, a preliminary diagnosis of stroke was made. As the patient was worked up for the stroke, his symptoms improved, and he was back to his baseline function within 48 hrs of presentation. What came to our surprise was that the stroke workup, including the initial CT scan with an angiogram, blood works (Hba1c and lipid panel), echocardiogram of the heart (ECHO), and Holter monitor was all unremarkable until an MRI head was done, which showed bilateral thalamic acute-sub acute infarct. This shows that AOP can be easily missed as it may not appear on the initial scans and workup and needs an adequate radiological study for diagnosis. Although some cases of AOP infarction are reported in the literature, the presentation with transient mild symptoms makes our case an interesting one.

Assessment of Percheron infarction in images and clinical findings

OBJECTIVE

To assess the imaging and clinical features of patients with an artery of Percheron infarction comprehensively.

METHODS

Of 6539 patients with a first-ever stroke, 18 patients with a Percheron infarction were enrolled, and their images and clinical data were retrospectively investigated.

RESULTS

All patients underwent neurological intensive care unit (NICU) management. The initial symptom of a Percheron infarction included dizziness, transient blurred vision, double vision, barylalia, cerebellar ataxia, drowsiness, and a coma. Subsequent symptoms differed for the three subtypes of Percheron infarction, and the three subtypes are bilateral paramedian thalamic infarction with midbrain involvement, bilateral paramedian thalamic infarction without midbrain involvement, and bilateral paramedian and anterior thalamic infarction without midbrain involvement. Between favorable and unfavorable outcomes, there was no significant difference in the following patient characteristics including current smoking, hypertension, diabetes, hyperlipidemia, hyperhomocysteinemia, heart disease, time from stroke onset to medical care, and Glasgow Coma Scale score at admission (P>0.05), but there were significant differences in both the National Institute of Health stroke scale (NIHSS) and Acute Physiology and Chronic Health Evaluation II (APACHE II) score at admission (P<0.05). If the midbrain or larger infarct volume was involved or hemorrhagic transformation occurred, outcomes of a Percheron infarction were frequently unfavorable.

CONCLUSION

The clinical presentation of patients with a Percheron infarction is variable; early recognition, image performance, NICU management, NIHSS, and APACHE II score would help in diagnosis, evaluation, and treatment.

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.

Artery of Percheron Infarction as an Unusual Cause of Korsakoff's Syndrome

The Korsakoff syndrome is defined as "an abnormal mental state in which memory and learning are affected out of all proportion to other cognitive functions in an otherwise alert and responsive patient." Confabulation refers to false or erroneous memories arising, not deliberately, in the context of a neurological amnesia and is often thought of as pathognomonic of the Korsakoff syndrome. Although the exact pathophysiology is unknown, various studies have identified brain lesions in the thalami, mammillary bodies, and frontal cortex. We report a case of a 68-year-old male presenting with acute altered mental status on July 16, 2015. The neuropsychological dysfunctions included prominent Korsakoff's syndrome, which became apparent when the altered mental status resolved. Amnesia was accompanied by prominent confabulation, disorientation, and lack of insight into his own disability. Neuroradiological data indicated that the intralaminar and dorsomedial nuclei in bilateral thalami were infarcted by occlusion of the artery of Percheron. We believe that ours is one of few reported cases of Korsakoff syndrome in a patient with infarction involving the territory of the artery of Percheron. We conclude that bilateral thalamic lesions could cause Korsakoff's syndrome and the intralaminar and dorsomedial nuclei might be important structures in the pathogenesis of confabulation.