Saturday, February 21, 2009

Diagnostic Breakthroughs

''I never even heard of that disease before I got it -- and to tell you the truth, I don't think my doctor had, either.”

Many patients who face persistent nondiagnosis or misdiagnosis begin to lose faith that they will ever find a solution to their case. After seeing so many doctors, undertaking so many tests, and trying so many treatments, they no longer want to ride the emotional roller coaster of hope and disappointment and resign themselves to the possibility that they may never find an answer. At the same time, many doctors have the perception that a large portion of patients in this situation are hypochondriacs, have somatization disorders, or suffer from conditions which are beyond current medical understanding – in short, that these cases are “unsolveable.”

While there has been no scientific study of this phenomenon, an abundance of anecdotal evidence suggests that many of these prolonged and difficult cases are in fact solveable. It is not uncommon to hear stories of patients whose diagnsosis evaded numerous doctors, only to be quickly recognized by a later doctor with the right insight and experience to diagnose the condition. Some of the drivers behind this phenomenon are well detailed in Dr. Gurpreet Dhaliwal’s posting “The Distributed Knowledge of Medicine” on this blog. This underlines the need for patients to keep trying to find an answer and to not give up hope. At the same time, doctors must remind themselves that while these cases can be frustrating and it may be difficult to discern between those that are and are not solveable, many of these patients are in fact suffering from conditions that are defined, understood, and diagnoseable.

Narratives of patient cases which presented in a mystifying manner, eluded diagnosis, and were eventually resolved are widely available in The New York Times’ “Diagnosis” column, Discovery Channel’s “Mystery Diagnosis”, and the New England Journal of Medicine’s “Clinical Problem Solving” feature. A small sample of the difficult but solveable cases discussed in these features include Salmonella Choleraesuis, Teratoma, Jamaican Vomiting Sickness, Lemierre's disease, Meckel’s diverticulum, Quinine allergy, Carnitine Palmitoyltransferase Deficiency, Aortic Dissection, Addison's disease, Hodgkin's lymphoma, Idiopathic Diabetes Insipidus, Familial Mediterranean Fever, Tic Douloureux, Coarctation, Thoracic Outlet Syndrome, Ehrlichiosis, Sarcoidosis, Gout, Jimson Weed Poisoning, Hereditary Angioedema, Scurvy, Adrenal Carcinoma, Eosinophilic Pneumonia, Rocky Mountain Spotted Fever, Leptospirosis, and Adult Still's Disease, among many others.

Thankfully, the patients described in these columns had largely positive outcomes. But, given the challenges in diagnosing them we must think about those who were not so lucky. For each of these success stories, there must be many other patients who were unable to find their answer and suffered needlessly. Two autopsy studies (Lundberg 1998, American College of Chest Physicians 2001) show that about 40% of cases examined after death had been misdiagnosed and that a correct diagnosis would have resulted in a different treatment in approximated half of these cases (admittedly, these studies were performed on intensive care patients, so they may not be entirely representative of the broader patient population). We cannot overestimate the need for and value of a correct diagnosis.

The important takeaway is that patients facing complex and difficult diagnoses should not be dismissed as nuisances as many of these cases are in fact solveable. Diagnosis is as much art as science, requiring determined and proactive patients working with resourceful and empathetic doctors. The process can be long and frustrating, but both sides should draw inspiration from the widely available evidence that for many of these patients, an answer is out there.