By: Rosabel R. Young, M.D., M.S. Pharm, F.A.A.N., Q.M.E.
Certified, American Board of Psychiatry and Neurology with Added Qualifications in Neurophysiology
Board Certified in Brain Injury Medicine (American Board of PM&R)
Certified, American Board of Electrodiagnostic Medicine
Certified, American Board of Clinical Neurophysiology
When do seizures occur after TBI? Neurologists distinguish early post traumatic seizures from late post traumatic seizures.
Early: Immediately or within a few days after a brain injury, the brain may have small areas of bleeding and swelling. These act like irritants to brain tissue and can trigger one or several seizures. As the blood dissolves away and the swelling goes down, as can be seen with imaging studies like brain MRI, these “early post-traumatic seizures” resolve, or at least they are not likely to develop into permanent epilepsy. Typically, emergency room doctors will treat with antiseizure medications for one week, but the medical literature supports that it is safer to treat for 4 to 6 weeks in these patients because it takes four to six weeks for the small bleeds and swelling to resolve.
Late: If it seems that the symptoms have gone away or are improving over the next few months and then seizures develop six months later or more, the cause is due to scar tissue, which takes months to develop. Unfortunately, persons with late post-traumatic seizures are more likely to develop epilepsy, and those seizures do need to be treated for the long term, usually life-long. According to the medical literature, post-traumatic seizures can begin to occur up to 18-24 months later, as scar tissue has to “mature” and develop abnormal electric channels that “learn” how to make seizures. The seizure type will usually be focal impaired awareness seizures, with unpredictable abnormal behaviors that can be confused with anxiety, panic attacks, or even misdiagnosed as schizophrenia. Although psychological symptoms may also occur (depression, anxiety, etc.) it is important to be sure that the patient sees a neurologist for a physical examination and has all the necessary testing done before anyone assumes the problem is “just psych” and starts the wrong medications that may actually worsen epileptic seizures.
In addition to the physical neurological examination, necessary testing includes a brain MRI, 24-hour overnight EEG with video, and 72 hour ambulatory EEG. The brain MRI should include coronal slices through the temporal lobes, to view for hippocampal sclerosis, a common cause of post TBI epilepsy.
How late is Late? Although 18-24 months is the physiologic timing for the development of the abnormal electrical activity from TBI scar tissue, in clinical practice, it is common for patients to be unaware of seizure symptoms until years later, even 20 years after an injury. Epilepsy can develop in late adulthood as a result of a brain injury in childhood. Men who played football and had a few “minor” concussions in high school will suddenly have seizures with jerking or even a full gran mal convulsion in their 30s or 40s, even if there was no loss of consciousness at the time of the injury. When a neurologist sees such a patient, we can assume that individual has probably been having complex partial episodes since their high school head injury. I always ask about “spells” of confusion, word finding, momentary disorientation, lapses of awareness, memory loss, involuntary movements, arm or leg spasms, … and 90% of the time, patients with “new onset” seizures will recall having such episodes. For these patients, even if they only had one “documented” seizure, I perform the full testing and am more likely to diagnose them as having epilepsy and will provide appropriate treatment.
Therefore, all patients with head injury who experience even one episode of altered awareness, involuntary movements, or unexplained changes in behavior, should have a neurological examination. In my experience, the neurological examination is more sensitive than EEG or even MRI testing. Therefore, in my practice, all patients who have abnormal findings on physical neurological examination are sent for further testing even if they do not report any suspicious spells. Further testing includes Functional Brain MRI, PET (Positron Emission Tomography) scanning, SPECT scan, and other modalities.
Note: Dr. Young’s late mother, Rosario Riveras, worked at EFGC for over a decade before retiring in 2010. Rosario was a vital part of our organization and was key to implementing our Hispanic Outreach Program. We are forever grateful for the accomplishments Rosario made in the epilepsy community.
