Compared with conventional surgical techniques, computer assisted navigated total knee arthroplasty significantly reduces the risk of systemic emboli detected by transcranial Doppler ultrasonography (Journal of Bone and Joint Surgery [Br] 2006;88: 198-202). In the study's computer assisted group no patient had more than two detectable emboli, with a mean of 0.64 (SD 0.74). In the non-navigated group the number of emboli ranged from one to 43, and six patients had more than two detectable emboli, with a mean of 10.7 (SD 13.5).

The mnemonic SIGECAPS (standing for sleep disturbance, interest diminished, guilt, energy loss, concentration difficulties, appetite change, psychomotor retardation, suicidal ideation or acts) is used to diagnose depression in the United States. However, an improved version might be C GASP DIE, not least to get around the problem of the two S's (and trying to recall what they stand for). Here, D represents thoughts or acts of death (American Journal of Psychiatry 2006;163: 329-30).

Family history of stroke is a risk factor for ischaemic stroke, but other factors can confuse the picture. For instance, data analysis from two population based studies and a series of patients referred to hospital with recent transient …