Case Report
The patient is a 16-years-old Tunisian boy known for nephrotic syndrome
related to a minimal change disease diagnosed based on a renal biopsy in
October 2021. In February 2022, he was admitted to the Nephrology
department for a corticosteroid-resistant NS with severe adverse events
of glucocorticoids (Cushing syndrome, glaucoma, and dyslipidemia).On
clinical examination, the boy’s weight was 75 kg, his height was 1.68m,
and he was afebrile and had no respiratory symptoms. His blood pressure
was 130/70 mmHg with a heart rate of 80 beats per minute. He also had
lower limb edema related to his nephrotic syndrome. Regarding his
corticosteroid nephrotic syndrome, we decided to start CSA treatment at
a dose of 3mg/kg/day with progressive tapering of corticosteroids.
On the fifth day of CSA start, the patient presented two short left
clonic focal seizures with a duration inferior to two minutes. After one
minute, he had a third motor focal onset seizure with secondary
generalization and conscious alteration. The recovery of consciousness
was after 30 minutes. Apart from a high CRP, biological tests were in
the normal range and could not explain these symptoms (Table 1).
Intravenous sodium valproate was initiated quickly and we have not
objectified a new seizure. The cranial magnetic resonance imaging (MRI)
showed leptomeningeal enhancement with a predilection in the cerebellar
hemispheres (Figure 1). The cerebrospinal fluid (CSF) analysis
shoIntravenouswed normal cellularity with hyperproteinorachia (0.71g/l)
(Table 2) and the CSF bacterial culture was negative. In the meantime,
the patient experienced sinus tachycardia, with one episode of fever.
Therefore, we decided to perform nasopharyngeal RT-PCR for
SARS-CoV-2since the patient was in contact with a COVID-19 subject. The
test returned positive.
Although the RT-PCR for SARS-CoV-2in the CSF was negative, the data from
the MRI and the CSF analysis, along with the positivity of the
nasopharyngeal RT-PCR for SARS-CoV-2, led to the diagnosis of secondary
encephalitis to SARS-CoV-2infection. As a result, we decided to
discontinue CSA, being immunosuppressive, during the infectious period.
For the next ten days, the patient showed no recurrence of the seizure,
did not require oxygen therapy, and did not present any new symptoms.
After a second nasopharyngeal swab for SARS-CoV-2 that was negative, the
patient was declared cured. The analysis of the CSF of a second lumbar
punction analysis showed normal cellularity with normal glycorrhachia
and proteinorachia. The patient was discharged with a maintenance oral
dose of sodium valproate. Two weeks later, the patient had not
experienced any recurrence of neurological symptoms and he had a
persistent severe nephrotic syndrome. Therefore, we decided to restart
CSA treatment. Despite being under an anti-epileptic drug, the patient
experienced generalized tonic-clonic seizure one day after the
immunosuppressant resumed treatment. This allowed us to rectify the
diagnosis and relate the seizures to the CSA. A second cranial MRI
(Figure 2) showed a progression of the previous lesions and the
appearance of new cortical and subcortical hyperintensities in axial
FLAIR- weighted and diffusion in the biparietal and right frontal lobe
with an exaggerated meningeal gadolinium enhancement in front of these
lesions. Imaging, as well as clinical data and the causal link with the
taking of the treatment, the diagnosis of CSA-induced PRES, was
retained. As an alternative to CSA, we opted for Rituximab at a dose of
1g per dose (two doses spaced two weeks apart) with good clinical and
biological tolerance.