ABSTRACT
Hydrocephalus is a known complication of central nervous system (CNS) vasculitis secondary to infectious diseases. We present an unusual case of primary CNS vasculitis (PCNSV) complicated by communicating hydrocephalus. A patient in their 50s with a few months' history of headache, psychomotor slowing and frequent falls presented with an acute left temporo-parieto-occipital infarction. Angiography revealed multiple arterial irregularities in the anterior circulation bilaterally, CSF was inflammatory and the remaining study was negative, fulfilling criteria for possible PCNSV. One month after successful treatment with corticosteroid, there was worsening of gait, urinary incontinence and neuropsychiatric symptoms. The investigation was remarkable only for active hydrocephalus. An external ventricular shunt was placed, followed by a ventriculoperitoneal shunt, and cyclophosphamide was started with subsequent recovery. Our discussion is that communicating hydrocephalus in PCNSV, due to impaired CSF flow, should be considered on subacute/chronic worsening of patients with PCNSV.