VGF and Cognitive impairment: Sequence variation in the neurexin family of proteins has been associated with a wide variety of neurologic and psychiatric disorders,29 changes in neuropentraxin 2 have been associated with the cognitive dysfunction in AD,30,31 and abnormal VGF has been a robust finding and even proposed as a therapeutic target for neurodegenerative diseases.32 Together, these indications of faulty synaptic integrity could form the basis of the cognitive impairment in iNPH, but the underlying mechanism and correlation with reversal of symptoms after shunt placement warrant further investigation.