Case Report: Binocular blindness in reversible posterior encephalopathy syndrome revealing lupus

Introduction

The diagnosis of systemic lupus erythematous (SLE) is essentially clinical and is generally based on the presence of four or more of the 11 revised criteria established by the ACR, present concurrently or sequentially, without limitation of observation time. None of the criteria included ocular involvement. However, ocular involvement is present in one-third of patients with SLE.¹

Posterior reversible encephalopathy syndrome (PRES) was initially reported by Hinchey in 1996 and is described as a neurological disorder associated with several clinical conditions.^2,3 Headaches, visual disturbances, altered mental status with focal neurological deficits, and/or epileptic seizures are the main clinical features of PRES. Typical transient lesions, particularly involving the posterior part of the brain, are the key neuroimaging findings in this condition. Visual perception disturbances in posterior reversible encephalopathy syndrome (PRES) include hemianopia, visual neglect, and cerebral blindness, but not optic neuropathy.¹

The reported rate of PRES in the pediatric population is 0.4%,⁴ but it appears to be more frequent in those with renal disorders.^5,6 Neurological symptoms are related to vasogenic cerebral edema, the main pathophysiological mechanism underlying this condition.⁷ Urgent multidisciplinary management is imperative to improve patient outcomes.⁸

We report the case of a young patient with bilateral optic neuropathy optic neuropathy associated with PRES as the initial manifestation leading to the diagnosis of SLE.

Patient and observation

Diagnostic assessment

Electrocardiography revealed sinus tachycardia without any other abnormalities. Labs: Proteinuria and three-cross hematuria. Fundus: Stage I bilateral papilledema. Laboratory findings: lymphopenia 1100/mm³, normocytic anaemia, 10 g/dL Hb; creatinine, 95 μmol/L, hypoalbuminemia 18.7 g/L, proteinuria 1.72 g/24H (>50 mg/kg/day). Thyroid and immunological tests were also performed.

Blood tests identified normal serum levels of creatinine (65.0 μmol/L; normal value ≤120 μmol/L) and urea (6.7 mmol/L; normal value ≤ 7 mmol/L) with a normal ionogram (natremia = 141 mmol/L, normal range between 135 and 145 mmol/L; kalemia = 4.1 mmol/L normal range between 3.5 and 5 mmol/L), a normochromic normocytic anemia (Haemoglobin = 9.4 g/dl, normal value ≥ 12 g/dl) and a low prothrombin time (60%; normal value 100%).

We completed with a head computed tomography (CT) scan (Figure 1) revealing vasogenic edema involving bilateral parieto-occipital regions, on cerebral MRI: bilateral and symmetrical parieto-occipital cortico-subcortical signal abnormalities, suggesting reversible posterior encephalopathy (Figure 2). Abdominal ultrasound revealed ascites and bilateral pleural effusion of a moderate size.

Figure 1. CT scan revealing bilateral parieto-occipital hypodense lesions.

Figure 2. MRI revealing bilateral parieto-occipital lesions (axial section T 2 flair).

Discussion

This case is very interesting, as it describes a severe PRES presentation with good outcomes owing to early multidisciplinary management. In addition, this syndrome revealed SLE in a child with no relevant medical history.

PRES, initially reported by Hinchey et al.,³ has gained increasing recognition owing to the improved availability of neuroimaging, which is central to diagnosis.² As neuroimaging findings showed posterior leukoencephalopathy, it was first recognized as “posterior reversible leukoencephalopathy syndrome”.² Later, the term PRES was adopted to design this entity because both white and gray matter are involved.⁹

Whereas the pediatric population seems to be more at risk for PRES, its incidence may be underestimated.¹⁰ The reported rate in the pediatric population is 0.4%⁴ and it increases between 4 and 9%, in those with renal disorders.^5,6

Some conditions are especially associated with PRES, such as autoimmune diseases, hypertension, eclampsia, sepsis and shock.^8,9 Besides, renal failure, hematologic diseases, and their therapies (particularly corticosteroids and cytostatic agents) are the most frequently reported cases in pediatric patients.¹⁰ Liu found ten occurrences of PRES in patients with SLE, all of whom were female,¹¹ and the SLE activity disease index (SLEDAI) was almost third at the time of the onset of PRES.¹¹

The main pathophysiological mechanism underlying PRES is vasogenic cerebral edema, which has two possible theories. The first one postulates that when severe hypertension exceeds the cerebral vessel autoregulation capacity, cerebral hyperperfusion and endothelial injury occur, resulting in vasogenic edema. The second theory hypothesizes that self-regulation mechanisms lead to excessive vasoconstriction, resulting in cerebral hypoperfusion and ischemia, followed by vasogenic edema.^6,8

Furthermore, sympathetic innervations are less developed in the posterior cerebral areas than in the anterior ones, which explains the distinctive damage to the occipital and posterior parietal lobes, more vulnerable to rapid blood pressure variations.^5,8

The clinical presentation is commonly associated with headaches, confusion, vomiting, seizures, and visual disturbances in up to half of the cases. While diffuse, dull headaches often progress gradually, they can sometimes be described as a sudden “thunderclap”,⁵ In 2022 Sudan et al. reported a 32-year-old SLE patient presenting with acute vision loss and other findings diagnostic of PRES.¹²

Seizures are observed in 74-84% of patients in the literature.¹⁰ They are usually generalized as tonic-clonic types and occur several hours or days after the first clinical signs.^3,9 In fact, our patient initially a sudden onset of binocular blindness, generalized edema with hypertension, which were followed by refractory status epilepticus.

The diagnosis is based on the presence of a triggering condition, an hypertensive emergency, and specific neuroimaging findings.

PRES, which is both a clinical and radiologic entity, includes acute-onset headaches, vomiting, seizures, visual abnormalities, and parieto-occipital white matter changes on MRI.¹¹

The radiological abnormalities of PRES are evident on CT scans as hypodense lesions revealing white matter edema distinctly involving the subcortical areas of the parieto-occipital lobes. CT also allowed us to rule out other alternative diagnoses. Although, it is less accurate than cerebral MRI, which is considered as the gold standard tool to confirm PRES. MRI should be performed as soon as PRES is suspected because T2 and fluid-attenuated inversion recovery (FLAIR) sequences are sensitive to vasogenic edema. Hyperintense signals on T2 and FLAIR sequences and iso-or hypointense signals on T1 sequences are typical radiological findings in PRES.⁸ These signal changes were mainly detected in the bilateral occipital lobes, particularly in the white matter. However, gray matter involvement and symmetrical holohemispheric or unilateral lesions have also been described. Uncommon locations such as the cerebellar hemispheres, brainstem, basal nuclei, corpus callosum, and frontal lobes have also been reported.^8,9 Therefore, atypical neuroimaging abnormalities in children may make the diagnosis of PRES more difficult than that in adults.

Even though, the biological findings with positive antibodies for SLE associated with the clinical presentation and the typical CT and MRI findings supported the diagnosis.

As blood pressure values remained high, requiring antihypertensive treatment after stabilization,¹⁰ hypertension may be longstanding but unrecognized until the day of admission.

The management of PRES is not specific, but immediate symptomatic treatment is imperative to improve the prognosis. It includes antihypertensive agents, antiepileptic treatment, avoidance of harmful agents, and control of the underlying comorbidities causing hypertension.⁹ For the patient of Sudan et al. she was treated with antihypertensives and switched from injectables to oral in the subsequent days, with complete resolution of her symptoms.¹²

The aim of treatment, in the acute phase, is not to achieve normal blood pressure levels, but rather to reduce progressively the mean arterial blood pressure by 20-25% over the first two hours.⁸ Then, cautious normalization of blood pressure must be performed within 24–48 hours.⁹ Intravenous agents with rapid action that can be easily adjusted and well-known clinical effects, such as nicardipine, clevidipine, and labetalol, are recommended.⁷

Besides, antiepileptic treatment is the same as in any other clinical condition associated with seizures.⁹ Thus, benzodiazepines, valproic acid, levetiracetam, and magnesium are effective therapeutic alternatives.⁸ Upper airway protection and the need for mechanical ventilation must be continuously assessed, especially in comatose patients and those with prolonged epileptic seizures, as well as in the case of our patient, who presented with refractory status epilepticus and required intubation.

An early diagnosis associated to a rapid, appropriate, and multidisciplinary management is imperative to improve patients outcome.² In fact, the average time for symptom resolution in children is approximately 4.8 days (range: 1.5–14 days). A good prognosis is often the rule, as both the clinical and radiological features of PRES are reversible.⁷

A notable neuropsychiatric manifestation of systemic reversible encephalopathy syndrome (PRES) is the phenomenon of posterior reversible encephalopathy syndrome (PRES). The diagnosis and treatment of PRES can be challenging because of its potential to manifest as an active lupus illness or a side effect of immunosuppressant therapy. This can obscure the specific role of SLE in the development of PRES. On the other hand, there is even less information available about SLE patients diagnosed with PRES.¹²

Conclusion

This case study is a reminder of the importance of detecting the early signs of hypertension before encephalopathy occurs. In fact, emergency physicians and pediatricians should be aware of the possible diagnosis of PRES in children presenting with visual disturbances, neurological signs, and hypertension, and must initiate early symptomatic treatment pending neuroradiological confirmation. An underlying condition must always be screened for, especially an autoimmune disease.

Authors’ contributions

All the authors read and approved the final version of this manuscript.