Acute psychosis can represent a diagnosis challenge. Several disorders can be implicated, and some representing a life threatening condition. We report a rare case of acute psychosis with persistent soft neurological signs as a primary presentation of a central nervous system vasculitis.

A 23 year old man, with antecedent of depression, previous history of cocaine and marijuana abuse, admitted to an acute psychiatric ward with three days evolution of disturbed behavior, mainly isolation and immobility. On the psychiatric ward he appeared vague, with negativism, inattentiveness, and elementary and incoherent speech. He had unsystematised delusions. His neurological examination revealed a slight ataxic gait and discoordination, and signs of frontal lobe release. Initial extensive complementary study, including brain CT, EEG, and urine toxicology were negative. He began treatment with risperidone and clomipramine, with improvement of his mental condition, and by the second week he was able maintain a coherent speech. The neurological signs did not improve, and frequent falls appeared. We performed a brain MRI who revealed lesions compatible with vasculitis. The extensive liquor study was negative, with exception of proteins levels (56 md/dl). He was transferred to an internal medicine ward, treated with corticoesteroid. His condition improved in the following weeks and on discharge from Hospital he had recovered his mental status and was autonomous.

Psychosis is an uncommon presentation of central nervous system vasculitis. In cases of persistence or progression of the soft neurological signs, further complementary study is essential to exclude organic pathology.