Organic Brain Sydnrome (OBS) is a umbrella term that is used to describe an acute or chronic abberration in brain function due to a physical (ie. "organic") cause.
OBS may manifest in one or more of the following things:
This nebulous term tries to differentiate the cause of symptoms from that of a distinct psychiatric disorder (eg. Schizophrenia), although as medical science progresses this distinction gets more and more hazy - intense research in the area of functional/psychiatric illnesses has brought to light the high probability that many pyschiatric conditions stem from an organic cause. As a result of this disparity, the DSM-IV (aka the psychiatrist's bible) fails to recognise OBS as a legitimate diagnosis.
Nevertheless, OBS is term widely used by clinicians and allied health professionals as a place-holder diagnosis before a more specific diagnosis can be determined.
OBS can be split into 3 subgroups based on presentation and progression:
- acute OBS - delirium and acute confustional states
- chronic OBS - dementia
- subacute/encephalopathic OBS - progressively worsening states of dilirium which ultimately ends in dementia. (the "grey area" of OBS that neither fits acute nor chronic forms)
The common feature of all forms of OBS is an alteration in cortical function. This can come about from either a neurochemical abnormality or a structural abnormality. Examples of the latter are physical trauma to the brain, strokes, hydrocephalus, infection (meningitis, encephalitis) and mass lesions (eg. brain tumours).