SERUM NEURON-SPECIFIC ENOLASE, CARNOSINASE, AND THEIR RATIO IN ACUTE STROKE - AN ENZYMATIC TEST FOR PREDICTING OUTCOME

Background and Purpose Few admission variables adequately predict neur onal damage and prognosis in individual patients after stroke. Therefo re, there is a need for a reliable non invasive surrogate measure of c linical outcome. Methods We have developed a surrogate measure of stro ke outcome using the ratio of serum neuron-specific enolase (NSE) to h uman serum carnosinase (HSC) in 124 patients with acute ischemic or he morrhagic stroke and 61 matched control subjects. Serum NSE is known t o rise and HSC to fall after neuronal injury such as cerebral ischemia . Results Serum NSE levels were significantly higher and HSC levels lo wer in the patient group. The NSE/HSC ratio was elevated in patients w ith stroke: median (semiquartile) hemorrhages, 0.072 (0.033); infarcts , 0.039 (0.026): and control subjects, 0.019 (0.014), P=.0001. Patient s with a primary intracerebral hemorrhage had nonsignificantly higher ratios than those with an infarct (P=.082). The NSE/HSC ratio was sign ificantly associated with 90-day outcome measured in two out of three disability and handicap scales: modified Barthel Index (r(s)=-.34, P=. 001), modified Rankin Scale (r(s)=.30, P=.002), and Lindley Score (r(s )=.19, P=.057). Patients who died or were institutionalized had higher ratios than those who were discharged home: 0.069 (0.043) versus 0.03 8 (0.024), P=.011. Correlations between the NSE/HSC ratio and outcome were comparable to those between patient age or consciousness level on admission and clinical outcome. Conclusions We believe that measureme nt of NSE, HSC, or their ratio may be useful in the assessment of pati ents with acute stroke with respect to diagnosis and prediction of cli nical outcome.