Method, apparatus and computer program product for monitoring seizure activity in brain are disclosed. At least one parameter set sequence is derived from brain wave signal data obtained from a subject, wherein each parameter set sequence comprises sequential parameter sets and each parameter set comprises values for at least two signal parameters, the values being derived from the brain wave signal data. A path formed by each of the at least one parameter set sequence in a parameter space is determined, thereby to obtain at least one path. The parameter space is defined by the at least two signal parameters. At least one evolution indicator is calculated, each evolution indicator quantifying the evolution occurred in respective path formed in a given time period in the parameter space. The at least one evolution indicator is then employed to produce an indication of seizure activity in the brain wave signal data.