Selected clinical signs observed over time in L- and H-type BSE cases compared to controls. Signs are derived from observations and examinations. The horizontal axis represents the time points when neurological examinations were carried out; a symbol at a particular time point indicates that the sign was observed between this and the previous time point. The orange dotted lines indicate the time of estimated clinical onset, the light brown interrupted lines the time of death. Head shy/restless in crush: e.g. head tossing or backing off when faced in crush. Over-reactive to tactile stimuli: e.g. head tossing in response to touching of the head. Abnormal tests of over-reactivity: startle at flash, clipboard test or hand clap, kicking on stick test. Abnormal gait: e.g. dysmetria.