A man in his sixties with gait ataxia, dysarthria and mild cognitive impairment.

BACKGROUND: Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) syndrome is an immune-mediated, treatable and inflammatory CNS disease first reported by Pittock et al. (2010).

CASE PRESENTATION: We describe a 66-year-old man with previous history of diabetes, atrial fibrillation and hypertension, who was admitted to hospital with reduced general condition. He had experienced dizziness and unstable gait for a year, and had been periodically confused, especially in the previous month. MR imaging showed characteristic punctuate and curvilinear gadolinium enhancements in the pons. Our patient was diagnosed with CLIPPERS and was given corticosteroid treatment, initially methylprednisolone intravenously and then prednisone orally. Other differential diagnoses, such as CNS lymphoma, high-grade glioma, CNS vasculitis, neurosarcoidosis, demyelinating disease, Bickerstaff brainstem encephalitis, and acute disseminated encephalomyelitis were ruled out. The patient's condition improved dramatically after corticosteroid treatment.

INTERPRETATION: In 2017, the diagnostic criteria for CLIPPERS were published. Based on these criteria we were able to diagnose this patient with possible CLIPPERS, consistent with clinical symptoms, MRI findings, absence of better explanations for the condition, and clinical and radiological improvement after treatment with corticosteroids. An unequivocal diagnosis of CLIPPERS can only be established by characteristic pathological findings.