Evaluation of a tape removal test to assess neurological deficit after cardiac arrest in rats

SummaryBackgroundIn animal models of cardiocirculatory arrest (CA) it is of major interest to establish tests that can assess neurological damage after global cerebral ischaemia following CA. We evaluated a tape removal test with regard to detection of sensorimotor deficit, comparing it to the Neurological Deficit Score (NDS) in an established model of global cerebral ischaemia after CA in rats.MethodsRats were subjected to either 6 min of CA followed by cardiopulmonary resuscitation (CPR) or a sham operation. At 1, 3 and 7 days from the intervention, two different neurological tests were applied to all animals: in the tape removal test, the time was measured from attachment of adhesive tapes to the front paws until the animals removed them using their teeth and compared to latencies in the sham group. The NDS assessed two parameters (“travel beam” and “stop at the edge of a table”). Receiver operating characteristic (ROC) analysis was used to compare tests.ResultsIn the tape removal test, all animals of the CPR group showed a clear neurological deficit throughout the observation period with a marked recovery until day 7 (pre-CA: 4 s, 1 day: 180 s, 3 days: 165 s, 7 days: 44 s; data are median values). Latencies differed significantly from those of sham-operated animals (1 day: P < 0.001, 3 days: P = 0.003, 7 days: P = 0.006). ROC analysis showed that the tape removal test but not the NDS was appropriate for detecting neurological damage 3 and 7 days after restoration of spontaneous circulation (ROSC). Histological examination confirmed neuronal damage to the hippocampus, cortex, thalamus and striatum.ConclusionIn the present study, a clinically relevant sensorimotor deficit after global cerebral ischaemia following cardiac arrest in rats has been quantified for the first time by using a tape removal test. The tape removal test is a sensitive method that can be easily applied to test large numbers of animals in future studies.