We study spike-based sensor node communication using runlength-limited (RLL) coding to encode information in the temporal distances of the spikes. For such systems integrate-and-fire time encoding machines (IF-TEMs) are considered as an energy-efficient alternative to uniform sampling analog-to-digital converters (ADCs) at the receiver. In this regard, we present a spike detector that employs an IF-TEM with periodic reset followed by a demapper calculating log-likelihood ratios of the transmitted RLL symbols. We assess the communication performance based on the achievable rate between the RLL encoder input and the RLL decoder output. A comparison to the use of 1-bit ADCs shows that the proposed spike detection enables communication at significantly lower energy per bit to noise power spectral density ratio Eb/N0.