The formal extradition hearing against former Chilean president Augusto Pinochet will finally get underway in magistrate's court here Monday, but Pinochet's future may depend more on a hospital examination than the courtroom proceeding.

Eleven turbulent months have passed since Pinochet was arrested in London on a request for extradition by a prosecutor in Spain. Spanish authorities have charged the retired general with thousands of human rights violations during his 17 years as Chile's ruler, and they want him extradited to Madrid for trial on charges of torture and conspiracy.

With financial and legal support from conservative politicians here, Pinochet has fought extradition with the same vigor he brought to the long battle against his political adversaries in Chile. He has appealed every ruling that went against him. The key decision by Britain's highest court--holding that a former head of state charged with abuse of human rights can be brought to trial almost anywhere--is considered a crucial new precedent in the emerging field of human rights law.

Pinochet, who is living under house arrest in a London suburb, held unchallenged sway in Chile from 1973 to 1990.

The legal grounds for extradition rulings here are fairly clear, and it's generally assumed that Britain would grant Spain's request--if the decision were strictly a legal matter. In recent weeks, though, the Pinochet camp has been hinting that it may invoke his health as an issue that transcends the legal questions.

Friends say Pinochet, 83, is deeply depressed about his arrest and the political controversy it has spawned. Last week, he went to a London hospital for a diagnostic brain scan. Newspapers have since carried reports that he is suffering from dizziness and a heart problem.

As a legal matter, poor health would not necessarily bar extradition. But if Pinochet is widely perceived to be too frail to defend himself against the Spanish charges, there would be increased political pressure here to let him go home. Home Secretary Jack Straw, the cabinet officer responsible for legal matters, has broad discretion to stop the extradition proceeding.

Earlier this month, the Home Office decided not to bring charges against a London woman newly revealed to have been a Russian spy. The reasoning was that the former spy is 87, and her alleged crimes were committed decades ago. As conservative politicians quickly noted, that sounds a lot like Pinochet.