Japanese guidelines for idiopathic normal pressure hydrocephalus

Idiopathic normal pressure hydrocephalus (iNPH) is a syndrome showing gait disturbance, dementia and urinary incontinence in elderly patients. Because of non-specific symptoms and no evident antecedent disorders, diagnosis is often difficult. Japanese Society of Normal Pressure Hydrocephalus made clinical guidelines to help better understanding of iNPH and to provide more improvement on patients' quality of life and social care. Clinical significance of gait disturbance, obliteration of cerebrospinal fluid (CSF) space in high convexity region on coronal section of MRI and positive CSF tap test is noted. For treatment, CSF shunt operation with programmable valve is recommended. Based on these findings, the guidelines propose three levels of diagnostic criteria; possible, probable and definite. Flowcharts for diagnosis, indication of CSF shunt opearation and postoperative care are also made.