Reversible posterior leukoencephalopathy syndrome combined with left middle cerebral artery occlusion and unilateral imaging involvement: A case report

Abstract

Objective

Posterior Leukoencephalopathy Syndrome is a condition shown by specific brain changes. It mostly involves swelling in brain tissue. This paper talks about an unusual case of posterior reversible encephalopathy syndrome (PRES). A 38-year-old man with high blood pressure (highest recorded:200/100 mmHg) was hospitalized due to ``ongoing headaches for half a year, which got worse with nosebleeds over 3 days''. Tests showed swelling on the right side of the brain (observed as bright signals on T2/FLAIR and high ADC values) and blockage in the left middle cerebral artery.

Outcome

Experts from various fields confirmed the diagnosis of unusual PRES. Main point that stands out here: left MCA block led to increased blood flow on the opposite side to make up for it, causing 1-sided imaging effect. When blood pressure was lowered step by step (goal: systolic pressure of 130 mmHg or less), MRI taken a week later showed some reduction in swelling.

Conclusion

This case shows that blocked blood vessels along with sudden changes in blood pressure might cause unusual PRES patterns, and finding it early with careful blood flow control is key to a better outcome.

Introduction

This article presents a case of a 38-year-old male patient admitted for ``recurrent headaches over 6 months, worsened with epistaxis for 3 days. This man had high blood pressure in the past, with a maximum of 200/100 mmHg. Scans showed swelling on the right side of the brain in the frontal, temporal, and parietal areas (with bright spots on T2/FLAIR and high ADC numbers) and a blockage in the left middle cerebral artery (MCA). Experts from different fields decided the man had an unusual type of posterior reversible encephalopathy syndrome (PRES). The unusual part of this case is that the blocked left MCA caused too much blood flow on the opposite side, which showed up on the scans only on 1 side. Using step-by-step lowering of blood pressure (goal systolic pressure ≤130 mmHg) and nourishing nerves, an MRI done a week later showed some reduction in swelling. This example shows that blocked blood vessels mixed with sudden blood pressure changes can cause unusual PRES patterns. Identifying early and correct management of blood flow is key to better outcomes.

Case presentation

Basic details: A 38-year-old man who works for himself and is from Shanwei City, Guangdong Province, went to Shenzhen-Shantou Sun Yat-sen Memorial Hospital. He had ``headaches that have kept coming back for 6 months and got worse with nosebleeds for 3 days.'' Two days before he got to the hospital, a head CT at another hospital showed a large light area in the right frontotemporoparietooccipital part of the brain. Main reasons for admission were: (1) low density in the right front part of the brain (likely tumor, stroke, or high blood pressure affecting the brain); (2) high blood pressure level 3 (high-risk category); (3) nose bleeding. First steps in treatment were to manage blood pressure, use brain-protecting drugs, and examine the nose internally, which resulted in reduced head pain and stopped nose bleeding.

On the day of entry, an MRI of the head showed bright spots on T2/FLAIR and higher ADC levels in the right frontotemporoparietal area, indicating brain swelling. There was no diffusion limit on DWI, and the left MCA was blocked. Lab results indicated high levels of complement C3 at 1550 mg/L and C4 at 489 mg/L. In the physical check, blood pressure was 166/126 mmHg, the patient was fully aware, and there were no specific brain function problems.

A group of experts reviewed the case. A head MRA scan revealed a blockage in the left middle cerebral artery but no effect on the cortex. A DWI scan showed that there was no recent stroke. MRI with contrast and MRS scans found there were no tumors. Tests showed no signs of encephalitis or autoimmune issues, and a normal MRV scan ruled out blood vessel inflammation or problems with veins. The final diagnosis was unusual PRES. This was based on very high blood pressure reaching 200/100 mmHg, sudden changes in symptoms, and swelling due to fluid on the right side of the brain, which did not follow the usual pattern of circulation.

Therapeutic management

After agreeing with various experts, the patient received special treatment to manage blood flow stability and overall care. Blood pressure was kept at or below 130 mmHg to prevent low blood supply: initial treatment involved labetalol given through the vein, later changed to long-term oral medicines like valsartan and amlodipine [1] for immune system modification were made since complement levels were high, but no drugs causing nerve toxicity were used, Only neurotrophic drugs were used without using immunomodulatory therapy [2] care included levetiracetam to prevent seizures,-term mannitol for brain swelling (while monitoring kidney health), and protection for nerves with mecobalamin and citicoline [3].

Follow-up and outcomes

After 1 week in the hospital, new MRI results showed decreased unusual signals in several parts of the brain, including the right front, side, and back regions, as well as deep brain areas. Blood flow imaging showed low blood movement, hinting at nerve coating loss [4] scans showed fewer nerve pathways in the front, side, and top right brain regions [5] results found small blood deposits in the brain's central area [6] blockage in the left middle artery and hardening of brain arteries stayed the same, aligning with the typical progress of PRES [[7], [8], [9]].

Discussion

Reversible posterior leukoencephalopathy syndrome, now called PRES, has changed names since it was first described more than twenty years ago. This change shows that it can affect both white and gray brain matter, not just the areas with posterior circulation. Though people still discuss it, PRES is preferred because it highlights reversible symptoms and more parts of the brain [10] cause of PRES is tied to 2 main ideas: 1 is that sudden high blood pressure may damage the brain's ability to manage blood flow, leading to problems with the blood-brain barrier. The other is that areas in the back of the brain lack sympathetic nerve coverage, making them more likely to be harmed by high blood pressure [11,12].

This case shows a special way of causing unilateral anterior circulation PRES. A blockage in the left MCA caused the opposite side to have increased blood flow, going over the body's limit of 150 mmHg. High levels of complement C3/C4 suggest that immune-related damage to the blood vessel lining, along with high blood pressure, made the swelling in the brain worse. It was crucial to rule out similar conditions in the diagnosis [13] infarction was not the cause because there was no sign of it on DWI [14] edema was ruled out as MRV results were normal [15] cerebral vasoconstriction syndrome was also dismissed because there were no sudden severe headaches nor the typical ``string-of-beads'' pattern on angiography [7,16].

Medical advice stresses the importance of finding problems early and managing high blood pressure strongly, aiming to lower systolic pressure to 130 mmHg or less in a short time [16] levels of complement suggest checking for autoimmune diseases, and keeping a watch on long-term ischemic risks is crucial after blood vessels are blocked. The situation shows that blocked blood vessels and sudden changes in blood pressure can cause unusual patterns of PRES, pointing out the need for careful control of blood flow to better the outcome [17].

Conclusion

Early detection of PRES depends on scans and observing blood pressure patterns. Quick action can undo the swelling. High complement levels might suggest a role of the immune system, calling for more study [18] situation highlights the need for custom high blood pressure care in PRES with blood vessel health problems [[19], [20], [21], [22]].

Patient consent

The patient is a 38-year-old male from Shanwei City, Guangdong Province, who was admitted to Shen-Shan Sun Yat-sen Memorial Hospital on March 7, 2025, due to ``recurrent headaches for over 6 months, worsened with epistaxis for 3 days.'' The patient was diagnosed with atypical posterior reversible encephalopathy syndrome (PRES) combined with left middle cerebral artery (MCA) occlusion following clinical evaluation, imaging studies (including CT, MRI, MRA), and multidisciplinary consultation.

The authors of this case report (``Reversible Posterior Leukoencephalopathy Syndrome Combined with Left Middle Cerebral Artery Occlusion and Unilateral Imaging Involvement: A Case Report'') wish to publish details of the patient’s medical history, clinical findings, diagnostic processes, treatment interventions, and follow-up imaging results (Fig. 1, Fig. 2, Fig. 3) for educational and scientific purposes.

Fig. 1.

Craniocerebral CT and MRI imaging findings of the patient. A is from the CT scan on March 1,2025: there is a low-density area in the right frontotemporoparietal lobe with unclear edges. B through I are from the MRI scan on March 10,2025: the T2-weighted image shows a bright area, while the T1-weighted image shows a dark area. The apparent diffusion coefficient sequence is also bright, and diffusion-weighted imaging along with other signals and enhanced scans show no changes. This indicates there are white matter problems in the right frontotemporal occipital lobe and basal nucleus, as well as swelling due to leaky vessels, and there is a blockage in the left middle cerebral artery.

Fig. 2.

MRI of the brain after treatment. The MRI scan done on March 18,2025, showed smaller lesions in the white matter of the right frontotemporal occipital lobe in the subcortical and basal nuclear areas than before.

Fig. 3.

Blood pressure change of the patient before and after onset of RPLS. Blood pressure levels shift when PRES is diagnosed and treated.

The patient has been fully informed of the content and purpose of this case report, including the use of anonymized clinical data and de-identified imaging materials. The patient understands that personal identifiers (eg, name, specific contact information) will not be included, and all images will be presented in a manner that prevents direct recognition. The patient has been assured that participation is voluntary and that they may withdraw consent at any time without affecting their ongoing care.

After careful consideration, the patient has provided explicit written consent for the publication of this case report and associated materials. The informed consent of the patient is attached as an appendix at the end of the article.