Frontal lobe blood flow (Nicolas et al 1993) and metabolism (Volkow et al 1992) may decrease in alcoholics before significant shrinkage or major cognitive problems become detectable (Nicolas et al 1993; Wang et al 1993). Cognitive functions and motor coordination may improve at least partially within three to four weeks of abstinence (Oscar-Berman et al 1997; Sullivan et al 2000) accompanied by at least partial reversal of brain shrinkage (Shear et al 1994; Pfefferbaum et al 1995) and some recovery of metabolic functions in the frontal lobes (Johnson-Greene et al 1997) and cerebellum (Martin et al 1995; Seitz et al 1999). Frontal lobe blood flow continues to increase with abstinence, returning to approximately normal levels within four years (Gansler et al 2000). Relapse to drinking leads to resumption of shrinkage (Pfefferbaum et al 1995), continued declines in metabolism and cognitive function (Johnson-Green et al 1997), and evidence of neuronal cell damage (Martin et al 1995).
