Minerva

Whether a single head injury can cause Parkinson's disease has been debated for nearly 200 years. A case report in the Journal of Neurology, Neurosurgery, and Psychiatry (1999;66:380-5) shows how magnetic resonance imaging was able to identify infarction of the left caudate nucleus extending into the lentiform nucleus in a patient who had developed signs of Parkinson's disease within six weeks of a head injury in a traffic accident. So the answer seems to be that acute trauma may cause the disease, but this is very rare.

When should a patient with necrotising pancreatitis have surgery to remove the necrotic tissue? Only rarely, says a review in the British Journal of Surgery (1999;86:147-8). The risks of surgery outweigh the benefits if the necrotic tissue is sterile. If, however, fine needle aspiration shows that the tissue is infected, surgical debridement gives the best chance of saving the patient's life.

Radiologists at the Mayo Clinic are convinced that virtual colonoscopy is the coming technique for screening for colorectal cancer—though they accept that a lot more evaluation is needed (Gut 1999;44:301-5). The test uses a spiral computed tomographic scanner to acquire data that is processed offline to yield two dimensional and three dimensional images. The patient's colon has to be distended with gas or air, but the procedure takes less than two minutes and the …