Spells. Things that go bump in the night. Such events are medical mysteries in need of solving. As a consulting neurologist, I've learned that part of my job is to be a "phenomenologist." To explain, if possible, the unexplained. To puzzle out mystery-symptoms and odd phenomena.

And one of the hardest (but most intellectually stimulating) diagnoses to make is that of "spells." That's what I call episodes that come and go, that have a beginning and an end-and something unusual in between. The basic process of diagnosing spells should be familiar to anyone who has taken a squeaking car to a mechanic. The one time that the car doesn't squeak is when the mechanic is inspecting it. So the mechanic has to make an analysis based on what you describe.

The same thing occurs in diagnosing people with spells. When an attack occurs in front of a doctor, it's usually easy to diagnose. But that almost never happens. Usually, all we have to go on is the description, or, hopefully, two descriptions-one from the person who had the spell and a second from someone else who was there to witness it.

Methodically, each of the two accounts is broken down into three parts-the events leading up to the attack, the attack itself, and what happened afterwards. Each account, taken one at a time, is based on what that person actually saw, heard and could remember, reported in a way particular to that person's abilities to observe and articulate. To make matters more challenging, the patient who had the attack often has significant gaps in their memory.

The list of potential underlying causes-what I think of as the differential diagnosis of things that come and go-spans multiple medical disciplines and is almost as broad as medicine itself. For example, let's assemble just a short list of conditions that can occur as episodic symptoms: seizures, pseudoseizures (seizure-like attacks of psychological origin), fainting spells, hypoglycemia, panic attacks, irregular heartbeats, dissociations, transient ischemic attacks (TIAs), migraine and vertigo.

What a list! It includes items from the fields of neurology, cardiology, psychiatry, endocrinology and otorhinolaryngology . And a physician is likely to run into each of these conditions at one time or another. Unfortunately for the purposes of diagnosis, patients don't arrive at clinics wearing signs around their necks saying, "I have a psychiatric condition," or, "My symptoms are due to my heart." All they know is that they have a problem they need help with.

Much of medical diagnosis is "pattern fitting" in which the patient's story is matched up against typical stories told by patients with different, identified conditions, and the best fit wins. Or, said another way: if it looks like a duck, walks like a duck and quacks like a duck, then it must be a duck.

But what if it looks like a duck, walks like a goose and gobbles like a turkey? What is it then? Well, that's what we call an outlier or atypical case, and we just do the best we can.

Medical tests are available for some of these conditions, like an electroencephalogram (EEG) for seizure cases, a 5-hour glucose tolerance test for hypoglycemia, and prolonged cardiac monitoring for irregular heartbeats. But each of these tests has its own strengths, weaknesses, and blind-spots that need to be figured into the diagnosis. (For example, an EEG might be normal in a patient who really does have seizures.) Then, for some of the conditions-like panic attacks, migraines and pseudoseizures-corroborating tests don't even exist.

Sometimes the available data permit a confident diagnosis and a specific treatment. In other cases the data allow one to narrow the possibilities to a short list, but not a single, final, definitive diagnosis. What then?

Sometimes watchful waiting is what's called for, also known as tincture of time. Once every obtainable clue has been assembled and they're still not enough to permit a firm diagnosis, then perhaps the best clue just hasn't happened yet and needs to be waited for.

Depending on which items are still on the diagnostic short-list, treatment might still be possible. For example, in a case in which it can't be decided if a patient has seizures, pseudoseizures, or both, it might be reasonable to try a decent dose of a good seizure-preventing drug, and watch to see if anything changes for the better.

Reading about inexactness in medical diagnosis might make some people uneasy. Perhaps it would be more comforting to believe that "a series of tests" could prove any diagnosis. For many conditions I'm sure that's exactly what happens, but it doesn't seem to be true for things that go bump in the night.

(C) 2005 by Gary Cordingley


About the Author
Gary Cordingley, MD, PhD, is a clinical neurologist, teacher and researcher. For more health-related articles see his website at:
http://www.cordingleyneurology.com