My husband's doctor (Neuropsyschology) diagnosed him with Neuro Cognitive Syndrome. What is that?

Psychiatrists and psychologists have special guidelines for classification of disorders. Neuro cognitive syndrome encompasses a few things that have the symptom of cognitive decline, e.g. loss of memory, confusion. It can be include mild or serious cognitive impairment. It can include dementia or amnesia. NCS is a fairly broad category that doesn't indicate what is physically causing the problem, only that the person is showing cognitive decline beyond what it is expected for his age.