Common Imitators of Epilepsy
- Fainting spells or syncope
- Migraines
- Movement disorders
- Heart rhythm disorders
- Sleep disturbances
- Staring spells, daydreaming
- Attention problems
- Rage attacks
- Other behavior problems
- Anxiety or panic attacks
It is a Challenge to Diagnose Seizures
In adolescents, diagnosing seizures can be challenging and can lead to many pitfalls. Because seizures are episodic and unpredictable events, they usually do not occur in the doctor’s office. Thus, a diagnosis of epilepsy is usually based on information presented by the person with seizures and their family. Together with results of diagnostic tests, doctors determine if the events are seizures and what type. Once a diagnosis of epilepsy is made, sorting out whether the patient’s disorder can be classified into a defined group, or an epilepsy syndrome, is done. Knowing the specific epilepsy syndrome can help people understand the cause(s) of the epilepsy, what other problems may be associated with the seizures and what the prognosis or future may be like. For example, some types of epilepsy respond better to medicines than others. Some epilepsy syndromes may be considered ‘benign’ and tend to go away at a certain age, while others are often difficult to control or require lifelong treatment. This article discusses the challenges of sorting out seizures, common seizure types and syndromes, and ways families and caregivers can observe and record seizures.
How often do doctors make errors diagnosing seizures? Since there is no single test to diagnose epilepsy, exact answers are not known. Yet clinical experience suggests that misdiagnosis is more common than one might imagine. Consider the following situations:
Bob was 17 years old when he developed episodes of staring, non-responsiveness and slight shaking movements of the body. He was diagnosed with complex partial epilepsy and was treated with carbamazepine and phenytoin for years before obtaining another opinion at an epilepsy center years later. VideoEEG monitoring recorded one of his typical seizures in which his heart stopped for 15 seconds; a heart problem was triggering the seizures. Antiepileptic medicines were stopped and a heart pacemaker was implanted. Bob has been completely free of episodes for 15 years. A videotape of his spell was shown at a medical meeting during a lecture on diagnosing epilepsy. The EEG and one channel of EKG were also shown. The audience had five choices: complex partial seizure, tonic clonic seizure, nonepileptic psychogenic seizure and cardiac syncope. By chance, 20 percent should have guessed the correct answer, but less than 5 percent made the correct diagnosis—even witnessing the episode.
Case 2 is Jennifer, 14 years old, who was seen by a pediatric neurologist after having two tonic-clonic seizures in six months. The EEG showed spike activity on both sides, more in the right frontal area, consistent with partial epilepsy. She was started on carbamazepine and had the doses increased each time she had another seizure. She was seen at an epilepsy center and her history revealed that all seizures occurred within an hour after awakening. She also had brief jerking movements of both shoulders while awake. Another EEG showed generalized spike-and-wave discharges. The diagnosis was changed to juvenile myoclonic epilepsy, a form of generalized epilepsy that causes absence, myoclonic and tonic-clonic seizures. Carbamazepine can make this type of epilepsy worse. She was changed to lamotrigine and has been seizure free for five years.
All epilepsy means is that a person has had two or more seizures that are not provoked by a medical problem. Once epilepsy is diagnosed, the next steps are to identify the seizure types and epilepsy syndrome. Clinicians should be very humble and not be “married” to their first diagnosis. If a person is not doing well or as expected, one of the first questions should be “is the diagnosis correct?” Too often, once a diagnosis is made, people focus on the information that supports the diagnosis and don’t look carefully at information that may lead to a different answer. This aspect of human nature can be dangerous, as mistaken diagnoses tend to persist under the care of different doctors. There are many other health problems that can masquerade as epilepsy.
Correct classification is critical to know what diagnostic tests may be needed and establish an appropriate treatment plan. Just as historical information can be misleading, diagnostic studies can also lead to wrong diagnoses, as shown in case 2 (see above). If the seizure type is incorrectly classified, the underlying cause of epilepsy may not be recognized or an inappropriate medication may be selected. This could lead to unnecessary side effects, incomplete control, or in some cases, worsening of seizure control.
Source: By Orrin Devinsky, M.D. Seizures and Teens: Sorting Out Seizures