This month the topic is post-concussion syndrome, which we looked at in the previous blog. It’s also the subject of my interview with Dr. Mel Glenn, a physical medicine and rehabilitation (PM&R) physician and Director of Outpatient and Community Brain Injury Rehabilitation at Spaulding Rehabilitation Hospital in Boston.

Post-concussion syndrome has been the subject of much debate among physicians for a long time. The following are some of the controversies associated with it.

No Universally Accepted Criteria for Diagnosis

Physicians disagree on what should constitute a diagnosis for PCS. The two widely referenced works, the ICD-10 and the DSM-IV, vary in the symptoms listed, the onset, and the severity of symptoms. (More about the ICD-10 and DSM-IV, and how PCS is diagnosed, will be covered in the next blog.)

Also notable is that while “postconcussional disorder” is listed in the DSM-IV, it’s absent from the most recent version, the DSM-V. Instead, symptoms that persist long after the initial trauma are covered by this category: “neurocognitive disorder due to traumatic brain injury.” Removal of “postconcussional disorder” from what is the primary diagnostic manual of mental disorders was based in part on many of the controversies listed below.

The Symptoms Are Nonspecific

Here again are some of the most common symptoms of PCS:

  • headaches
  • neck pain
  • dizziness
  • poor memory
  • poor concentration
  • fatigue
  • sleep problems
  • irritability
  • anxiety
  • sensitivity to light
  • sensitivity to noise

These are nonspecific symptoms, meaning they could be caused by any number of underlying problems. As a result, some people fit the diagnostic criteria for PCS despite having no history of a concussion, even though PCS is, by definition, something that occurs after such an injury. Some physicians question whether it’s clinically helpful to have a condition that’s so broad it can apply to people who are clearly not candidates for it.

The Risk of Misdiagnosis Is Substantial

Because the symptoms are nonspecific and overlap with those of many other conditions, it’s difficult for physicians to definitively diagnose PCS.

Patients who have sustained a mild TBI may be diagnosed with PCS when they are really suffering from PTSD, depression, anxiety, or a condition with a strong component of chronic pain such as chronic fatigue syndrome or fibromyalgia. Conversely, patients may be diagnosed with one of those conditions when they are really experiencing PCS. Or a patient may be suffering from both PCS and something else (like depression) that exacerbates the symptoms.

It’s Not Really a “Syndrome”

In medical terms, a “syndrome” is a set of symptoms that occur together and are all related to the same underlying cause. The appearance of one symptom in a syndrome means it’s highly likely that the other symptoms will appear, too.

But in PCS, the list of symptoms and their possible combinations are so large that there’s controversy over whether “syndrome” is the correct label for it. (Note that the DSM-IV did not call it a “syndrome” but rather a “disorder.”)

Is PCS Physiological or Psychological?

The fact that PCS has no associated etiology – that is, we don’t know the exact physiological mechanisms in the brain that cause it – is another reason why it’s controversial.

Instead, there’s a lot of evidence that psychological factors heavily influence PCS. Pre-existing psychological issues and post-concussion stressors are both related to PCS, indicating that it’s not entirely physiological in nature.

Money is another factor that is sometimes mentioned in this discussion. A 1996 meta-analysis found that people in the U.S. who stood to gain financially from a settlement had higher rates of PCS, indicating that money might be a factor. A 2002 study that looked at rates of PCS in concussion survivors in Lithuania, where the expectation of financial gain is low, found no difference in rates of PCS symptoms between subjects (people with a history of concussion) and controls (people with a history of an injury without a concussion), except for depression, alcohol intolerance, and worry about brain injury, which were more frequent in the concussion group. (You can read those abstracts here and here.)

Learning More About PCS

Still, despite all the controversy surrounding post-concussion syndrome, there are physicians, including Dr. Mel Glenn, who are devoted to the medical treatment and rehabilitation of people with symptoms long after brain injury. Despite how it’s described in textbooks and manuals, or viewed by various medical professionals, the fact is that many people suffer from symptoms for long after their initial concussion.

You can learn more about post-concussion syndrome by watching my interview with Dr. Glenn here.

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If you think you may have a medical emergency, call 911 immediately.

Thanks to these colleagues for the website photo opportunities:

Kam Gardner, MS, CCC-SLP, Speech-Language Pathologist
Raymond Samatovicz, MD, Physiatrist, Brain Injury Medicine Specialist
Kaiser Foundation Rehabilitation Center, Vallejo, California