P3C336: Evaluation and Management of Altered Mental Status in a Patient with Sickle Cell Disease and Systemic Lupus Erythematosus

Introduction: Sickle cell disease (SCD) and systemic lupus erythematosus (SLE) are both uncommon disorders that can cause vascular disease. When encountered in the same patient, identifying the etiology of a complication can be challenging, yet crucial, as the treatments differ significantly. Stroke in children with SCD is unfortunately common, with 18.1% suffering ischemic stroke by age 18 years. Neuropsychiatric lupus is also common, occurring in 40% of patients with SLE in their lifetime. Evaluation and management of AMS in a patient with both SCD and SLE requires careful consideration as these processes can mimic one another.

Case Description: A 19 year-old female with SCD and recent diagnosis of SLE presented with AMS complicated by status epilepticus and requiring intubation for airway protection. Ammonia at presentation was 111 μmol/L. Limited MRI at presentation was negative for acute stroke. Complete MRI was acquired on hospital day four and demonstrated small infarcts in the MCA-ACA and MCA-PCA watershed territories along with pronounced vascular narrowing. Hemoglobin S fraction was 65% at admission. An exchange transfusion was performed given the severity of her presentation.

Following extubation, her neurologic examination was notable for waxing-and-waning mental status. Repeat MRI was obtained in a period of increased confusion on hospital day nine and revealed interval development of abnormal foci of hyperintensity in the bilateral basal ganglia. Despite an initial laboratory evaluation suggestive of well-controlled SLE, steroids and anticoagulation were initiated as empiric management of neurovasculitis. She did not immediately return to her neurologic baseline. Lysinuric protein intolerance was considered in the differential given her unusual presentation with hyperammonemia, but additional laboratory evaluation was negative.

Anti-neuronal antibodies sent from the serum and CSF were positive. She received cyclophosphamide and rituximab as treatment for neuropsychiatric SLE and her symptoms swiftly resolved.

Discussion: This patient’s case was challenging due to the lack of overt symptoms of a lupus flare that often accompany neuropsychiatric lupus. Furthermore, 40% of patients with neuropsychiatric SLE will have a normal MRI. Vascular changes attributable to SCD were present, but did not correlate with her clinical presentation. The diagnosis was aided by multi-disciplinary team conference and detection of characteristic antibodies. We speculate that she may have been predisposed to neuropsychiatric SLE due to SCD-induced vascular narrowing.

Conclusion: Patients with SCD and SLE are rare with even fewer cases of SCD and neuropsychiatric SLE reported. This case demonstrates the challenge of identifying the etiology of AMS in a patient with both SCD and SLE. Furthermore, this case highlights that stroke is not always the cause of AMS in SCD. Multidisciplinary consultation and careful laboratory and radiologic assessments are crucial for informing the right treatment plan.