|The head of neurosurgery at St. Michael's Hospital says it's likely a woman's death 17 days after a chiropractic neck manipulation was caused by a brain swelling unrelated to that treatment.Dr. Richard Moulton testified yesterday at an inquest into the death of Lana Dale Lewis that it's his opinion that a thrombosis, a blood coagulation, in brain sinuses caused her death.Lewis, 45, a mother of three, died in September, 1996, after suffering two strokes. She went to Queensway hospital Sept. 1, complaining of dizziness and difficulty seeing. Tests showed she'd had a stroke. Lewis was released from hospital Sept. 6 but collapsed four days later and died Sept. 12. An autopsy attributed her death to a stroke. Moulton told crown counsel Tom Schneider yesterday that the thrombosis likely occurred spontaneously but could possibly have stemmed from an abnormality of the blood.He noted that Lewis had elevated levels of hemoglobin in the blood, indicating it may have been abnormally thick "and therefore more prone to coagulate."Quoting a January, 2001, report he prepared on Lewis' death, Moulton said that stroke from chiropractic manipulation occurs through the mechanism of vertebral artery dissection — a splitting of the artery that allows blood to flow in between its inner and outer vessel walls. "The mechanism appears to be absent in this case," he quoted his report as saying.When asked by Lewis family lawyer Amani Oakley why he had not taken into account Lewis' complaints about neck pain and headaches following her chiropractic treatment in late August, 1996, he replied that neither neck pain nor headaches necessarily point to arterial dissection. "It's a symptom, helpful only with other evidence," Moulton said.He agreed with Oakley that a pathology report indicates that the blood coagulation in Lewis' brain was secondary to an original injury.The inquest before presiding coroner Dr. Barry McLellan continues today.