Sleep deprivation disrupts the communication between one’s pre-frontal cortex and many other parts of their brain, resulting in impulsivity as well as poor decision making and conceptual ability.  These symptoms can also be observed in those subject to lobotomy.  In the barbaric procedure, an metal spike was driven into the prefrontal cortex, destroying a portion of it.  Drawing on this and my own experience with chronic sleep deprivation, lobotomy seems an apt comparison.

 

Reference.  Why We Sleep by Matthew Walker