Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 50 3 2012 03 15 216 221 EN Hossein Pourmahmoodian Department of Neurology, Iranian Center of Neurological Research, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran. Hossein Ali Ghelichnia Omrani Department of Neurology, Iranian Center of Neurological Research, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran. Mohammad Hossein Harrirchian Department of Neurology, Iranian Center of Neurological Research, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran. Mojdeh Ghabaee Department of Neurology, Iranian Center of Neurological Research, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran. Babak Zamani Department of Neurology, Iranian Center of Neurological Research, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran. Majid Ghaffarpour Department of Neurology, Iranian Center of Neurological Research, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran. 2015 09 28 Primary angiitis of the central nervous system (PACNS) is an idiopathic disorder (vasculitis) restricted to the central nervous system (CNS). It often presents with focal neurological deficits suggesting stroke or a combination of confusion and headache. We herein report three cases with various combinations of fever, partial seizure, encephalopathy, paresis, headache and ataxia. One of them was initially treated as herpes simplex meningoencephalitis, but further investigations revealed primary angiitis. Primary angiitis of the CNS has protean manifestations and should always be considered in patients suspicious to have CNS infection or stroke, particularly who does not respond to the routine treatments. Clinical data, exclusion of differential diagnoses and typical angiography seem to be enough to justify the diagnosis in the majority of cases. https://acta.tums.ac.ir/index.php/acta/article/view/3886 https://acta.tums.ac.ir/index.php/acta/article/download/3886/3861