A New Focus on Reducing Misdiagnoses

November 1, 2006
Kathy Stone

epilepsy, migraine, headache, Parkinson disease, parkinsonism

An ever-present concern facing neurologists is the potential for misdiagnosis. Misdiagnosis is costly to patients because it may prevent them from getting proper treatment for their disabling disorder. It's costly to neurologists through medical liability claims. A 2004 analysis of 300 paid neurology liability cases showed that 167 (55.6%) resulted from errors in diagnosing illnesses.1 The average indemnity paid in these cases was $452,811. And misdiagnosis is costly to society when medical professionals are discouraged from reporting medical errors because of an environment that punishes the messenger.

The Patient Safety and Quality Improvement Act of 2005, recently signed into law by President George W. Bush, directs the Department of Health and Human Services to establish a process for the voluntary and confidential reporting of medical errors to patient safety organizations in an effort to develop ways to improve patient safety and reduce medical errors.

"The health care community has long been committed to improving patient safety, and significant progress has been made through new technology, research, and education," said J. Edward Hill, president of the American Medical Association, in a statement issued after the bill was signed into law. "This patient safety law is the catalyst we need to transform the current culture of blame and punishment into one of open communication and prevention."2

More frequent studies that focus specifically on avoiding misdiagnosis and the recently passed legislation should have a positive impact on decreasing misdiagnosis and reporting errors. Experts in migraine, Parkinson disease (PD), and epilepsy shared insights with Applied Neurology about factors that contribute to misdiagnosis. Factors include focusing on symptoms to the exclusion of other tools; omissions in training and education; and the inability to capture timely observations of an episode.

THERE'S MOre to A headache Diagnosis than Symptoms

The misdiagnosis of migraine as tension-type headache has "potentially significant consequences because it may preclude patients with disabling headaches from receiving appropriate treatment," wrote Robert G. Kaniecki, MD, in his paper "Migraine and tension-type headache: An assessment of challenges and misdiagnosis," published in Neurology.3

For too long, the primary emphasis for diagnosing headache has been on symptoms alone, Kaniecki, a neurologist at the University of Pittsburgh Headache Center, told Applied Neurology. "Physicians typically spend too much time on symptoms. It's not effective nor is it efficient," he said. "Unfortunately, when we try to base our diagnosis on symptoms, we lose sight of the fact that there are overlapping symptoms" between migraine and other types of headache.

Kaniecki said that only about half of migraine sufferers receive an accurate initial diagnosis. Many people with migraine are given an initial misdiagnosis of tension-type or sinus headache. The pattern of the recurrent headache and the level of disability are more important factors in diagnosing migraine than the symptoms, according to Kaniecki. If it's episodic, lasting from 4 to 72 hours, "9 out of 10 times it's going to be a migraine," explained Kaniecki. "We need to teach residents and students that migraine can masquerade as tension-type headache."

Migraine is usually characterized by the presence of throbbing and pain on one side of the face. Neck pain is usually equated with tension-type headache. "But the location is not as important as you might think, and the symptoms are not as important. They both can vary."

Kaniecki drew an analogy to a heart attack, in which a symptom may be an aching arm. Like a migraine symptom, "a heart attack can manifest itself in different ways."

More training for Parkinson diagnosis

Of 238 new patients referred for evaluation at the Maryland Parkinson's Disease and Movement Disorders Center in Baltimore over a 1-year period, 35 (20%) had previously received a misdiagnosis by a neurologist. Stephen G. Reich, MD, a neurologist and codirector of the Center, said that the sources of the errors were failure to recognize PD, misdiagnosis of PD, and inability to identify a psychogenic movement disorder.4

Reich said that the best strategies to prevent misdiagnosis are to take a better medical history and to improve training geared toward recognizing the most common manifestations of PD. "In all cases, a correct diagnosis was reached on purely clinical grounds and not as a result of additional testing," said Reich.

Improved education would reduce misdiagnosis, Reich added, and should focus on identifying the various presentations of PD, distinguishing PD from essential tremor, detecting clinical red flags that suggest a parkinsonian syndrome, recognizing drug-induced parkinsonism, and knowing the features of psychogenic movement disorders.

"Virtually all of my diagnoses were based on a history and physical and a more careful bedside approach and knowledge about potential pitfalls," said Reich, who presented his research at the American Academy of Neurology Annual Meeting in Miami in April 2005.

Use of technologic resources also can make a big difference in fleshing out a diagnosis. For example, in a recent study of 9 patients in whom psychogenic parkinsonism (PP) was suspected, a team from the Department of Neurology at Saint-Antoine Hospital in Paris revisited the diagnosis using a combination of methods, including clinical examination, electrophysiologic recordings, and [123I]FP-CIT single photon emission computed tomography (SPECT). Use of these 3 technologies resulted in reclassification of the diagnosis as combined PP and PD in 6 patients, leaving only 3 patients with a diagnosis of PP.5 Electrophysiology was used to clarify clinical suspicion of a psychogenic cause, and [123I]FP-CIT SPECT was used because of its specificity in identifying whether dopaminergic denervation--a sign of PD--is present. The research team concluded that their combination of diagnostic tools improved accuracy in distinguishing PP from combined PP and PD.

EEGs not foolproof for Epilepsy Diagnosis

Neurologists should be aware of the pitfalls of using electroencephalography when diagnosing seizures, according to Gregory Krauss, MD, a neurologist with the Johns Hopkins University Department of Neurology and Biostatistics in Baltimore. Many neurologists have been lured into assigning a diagnosis of epilepsy by an incorrectly read electroencephalogram (EEG), said Krauss.

When Johns Hopkins electroencephalographers reread EEGs for 46 patients who had been referred to its outpatient clinic, epilepsy was found to be misdiagnosed in 25 patients (54%).6 These 25 patients had EEG wicket patterns but no true spikes or sharp waves that were consistent with epilepsy. A clinical reevaluation of their reported seizure episodes added further evidence that dispelled the epilepsy diagnosis.

Misinterpreting EEG features is "a common problem," said Krauss, and not unexpected since most neurologists receive only 2 to 3 months of EEG training. EEG wicket patterns are usually benign and do not suggest the presence of epilepsy. Patients without major confusion during episodes are also unlikely to have epilepsy. Epilepsy tends to develop early in life, whereas wicket patterns tend to occur most often in people older than 33 years.

Another problem is that some neurologists are unable to get a proper description of the episode from their patients so that they can determine whether the episode was a typical epileptic seizure. "It's important to get an observation from someone else" other than the patient, said Krauss, because the patient may be confused and not remember the seizure episode. Currently, video-EEG monitoring, in which EEG data are coupled with video footage of the patient having a seizure, is considered to be more diagnostic than EEG alone and is used routinely to distinguish epileptic seizures from psychogenic or other types of nonepileptic seizures. However, physicians need to be aware of specific motor activity that distinguishes epileptic from nonepileptic seizures.

The 25 Johns Hopkins study patients in whom epilepsy was initially diagnosed ultimately received new diagnoses that included near-syncope, psychogenic nonepileptic seizure, anxiety, hyperventilation, migraine, and postconcussive syndrome. The misdiagnosis of a nonepileptic condition as epilepsy led to problems ranging from the patient's frustration when the error was realized to inappropriate treatment with antiepileptic drugs for, in some cases, 2 years or longer, according to the study. *

References

1. PIAA Neurology Claims. Rockville, MD: Physician Insurers Association of America; 2004:20850.

2.Hill JA.AMA celebrates health care safety win for America's patients. Available at: www.ama-assn.org/ama/pub/category/15374.html. Accessed October 25, 2005.

3. Kaniecki RG. Migraine and tension-type headache: an assessment of challenges and misdiagnosis. Neurology. 2002;58:S15-S20.

4. Cornelius J, Reich SG. Diagnostic errors observed in patients referred to a Parkinson's disease and movement disorders clinic. Neurology. 2005;64(suppl 1):A75.

5. Benaderette S, Fregonara PZ, Apartis E, et al. Psychogenic parkinsonism: a combination of clinical, electrophysiological, and [(123)]-FP-CIT SPECT scan explorations improves diagnostic accuracy. Mov Disord. October 6, 2005 [epub ahead of print].

6. Krauss GL, Abdallah A, Lessor R, et al. Clinical and EEG features of patients with EEG wicket rhythms misdiagnosed with epilepsy. Neurology. 2005;64:1879-1883.