An Atypical Presentation of CLIPPERS, a Challenging Diagnosis of Reversible Early-Onset Dementia.

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is a rare inflammatory disorder featured by pontocerebellar dysfunctions and, in some cases, later cognitive disturbances. Here, we describe an atypical presentation of CLIPPERS, characterized by clinical onset with neuropsychiatric and cognitive symptoms. A 45-year-old man was referred to our Memory Clinic due to difficulties at work for over a month, caused by confusion and asthenia. Furthermore, insomnia and mood changes appeared. These disturbances were unresponsive to antipsychotic and antidepressant drugs. At admission, the patient presented also with severe cognitive impairment, urinary incontinence, ataxic gait, and limitation of lateral conjugate gaze. During the hospitalization, the patient underwent cerebrospinal fluid analysis, serum systemic autoimmune disorders laboratory research, neoplastic markers analysis, and brain MRI scan. The radiological and laboratory findings were compatible with the diagnosis of CLIPPERS. The sudden clinical and radiological improvement of the patient's conditions, after only a week of steroid therapy, further confirmed our clinical suspicion. The present case enhances the necessity to consider CLIPPERS in the differential diagnosis of pre-senile cognitive impairment, even in the absence of early pontocerebellar neurological signs. Before the spreading of the neuroinflammatory and degenerative processes, CLIPPERS represents one among the few possible reversible causes of cognitive decline.