Although it now should be clear that a concussion can be diagnosed without loss of consciousness as a symptom, would a defense expert be correct in saying that loss of consciousness signifies a mild concussion and complete recovery from any related symptoms should be expected within a period of 6 weeks to three months following the event?
When a practitioner uses the terms “mild traumatic brain injury”, it may have the unintended consequence of making the injury seem trivial or insignificant. Dr. Nathan Zasler in this chapter in Medical Rehabilitation of Traumatic Brain Injury noted “modifiers such as subtle, minimal and minor are to be discouraged. Practitioners must understand that the term “mild” describes only the initial insult relative to the degree of neurological severity. There may be no correlation with the degree of short or long term impairment or functional disability.” See Zasler, M.D., Neuromedical Diagnosis and Management of Post-Concussive Disorders in Medical Rehabilitation of Traumatic Brain Injury, 133-134 (Korn and Zasler, EDS., Hanley and Belfus, 1995).
The American Congress of Rehabilitation Medicine defines mild traumatic brain injury as the traumatically induced physiologic disruption of brain function. This may be manifested by any alteration in mental state at the time of the accident such as feeling dazed, disoriented or confused. It may cause physical symptoms such as nausea, vomiting, dizziness, headache, blurred vision and fatigue. It may cause cognitive deficits such as problems with attention, concentration, perception, memory, speech and language and executive functions. It may include behavioral changes such as irritability, quickness to anger, emotional lability and disinhibition. Mild Traumatic Brain Injury Committee of the Brain Interdisciplinary Special Interest Group, American Congress of Rehabilitation Medicine, Definition of Mild Traumatic Brain Injury, 8 J. Brain Trauma Rehab. 86-87 (1993). As can be seen by comparing the definition of concussion and mild traumatic brain injury, they are synonymous.
It has been reported that 10-15% of the patients suffering a mild traumatic brain injury remain symptomatic with post-concussive symptoms for a year or longer. Alexander MP. Mild Traumatic Brain Injury: Pathophysiology, Natural History and Clinical Management. Neurology, 1995; 45:153-60. After one year, it has been noted that 80% of mild traumatic brain injury patients are able to work, which means up to 20% are not. Dikmens, McLean A, Temkin N., Neurophysiological and Pyschosocial Consequences of Minor Head Injury. J. Neurol Neurosurg Psychiatry 1986; 49:1227-32. Even though reemployment frequently occurs despite persistent post-concussive symptoms, it has been noted that these post-concussive symptoms prevent patients from performing at their pre-accident levels. See Englander J., Hall K, Stimpson T, Chaffin S., Mild Traumatic Brain Injury in an Insured Population: Subjective Complaints and Return to Employment, Brain Inj. 1992; 6:16-6.
Regarding recovery issues, there are a number of factors to consider including the age of the injured person, whether that person has a history of previous concussion, the gender of the injured person and whether that person has any co-morbid condition. It is generally understood that the younger the age of the patient the greater likelihood that they will have more prolonged symptoms. It is not exactly understood why but it is postulated that the developing brain may be more sensitive to pathologic release of excitatory amino acid neurotransmitters (glutamine and aspartate) following trauma than adult brains. Sim A., Terry Berry-Spohr L., Wilson K.R.: Prolonged Recovery of Memory Functioning After Mild Traumatic Brain Injury in Adolescent Athletes, J. Neurosurg 108: 511-516, 2008. Adult women have a higher reported rate of post-concussion symptoms than men. Preiss-Farzanegan SJ, Chapman B., Wong T. M., Wu J., Bazarian J.J.: The Relationship Between Gender and Post-Concussion Symptoms After Sports Related Mild Traumatic Brain Injury. Phys. Med. Rehabil. 1. (3):245-253 (2009) and Bazarian JJ, Blyth B., Mookerjee S, Hee H., McDermott M.P.: Sex Differences and Outcome After Mild Traumatic Brain Injury, J. Neurotrauma 27 (3): 527-539, 2010. It is has been noted that large reviews on the topic of whether gender affects the recovery from concussion indicates a trend suggesting that gender is a risk factor for concussion severity but that more data is needed to make this conclusion. See Grady M, Concussion in the Adolescent Athlete, Current Problems in Pediatric and Adolescent Health Care, Vol. 40, Issue 7 (August 2010). It is believed that persons with certain pre-existing medical conditions such as migraine headaches, sleep problems, depression and anxiety and other mood disorders may be more susceptible to suffering long term consequences of concussion or mild traumatic injury. Although unknown why, it is speculated that individuals with such pre-existing conditions have less ability to compensate for concussion deficits as effectively as people without such conditions. Whether concussion simply worsens the pre-existing condition or whether it impairs the ability of the patient with the concussion to compensate or a combination of both is unknown. Id.
A pre-existing history of concussions may also play a factor in the ability of the concussed individual to recover. For example, neuropsychological testing in college football players with 2 or more concussion has suggested long term deficits in executive functioning. Collins MW, et al: RelationshipBetween Concussion and Neuropsychological Performance in College Football Players, JAMA 282: 964-970 (1999). Further studies show that collegiate athletes having suffered a concussion on two or more occasions took longer to recover verbal memory and reaction time on computerized neuropsychological testing than athletes without a history of concussion. Couvassin T., et al: Concussion History and Post-Concussion Neurocognitive Performance and Symptoms in Collegiate Athletes, JHTAL Train 43. 119-124. (2008)
In Neurology and Clinical Practice, 5th Ed., Chapter 54B-Trauma of the Nervous System: Craniocerebral Trauma, it is noted that adults with mild traumatic brain injury more commonly have significant cognitive deficits during the acute phase, although they typically have complete recovery within 3 to 12 months. Common sequelae of mild or moderate traumatic brain injury is post-concussion syndrome, a constellation of symptoms that can be very disabling weeks or even months after the injury. The most common symptoms are headaches irritability, dizziness, tinnitus, lethargy, and sleep disturbances. Approximately 30% of patients with mild or moderate injuries have one or more of these symptoms one week after their injury, but these usually subside within three months. However, about 7% of patients still report residual symptoms after one year, and the most common is persistent headache. That author notes that factors associated with an adverse long-term outcome after concussion include old age, prolonged post-traumatic amnesia, and reduced pre-morbid intellectual capacity.
Therefore, although it is less common, it is known that a concussion without loss of consciousness can result in symptoms that persist for a lengthy period of time. When I represent persons with such symptoms, it is important that he or she know that medical science supports them. As their lawyer, I must develop the necessary evidence to prove that they are suffering. The defense lawyer will argue that my client is exaggerating their symptoms for economic gain. In order to combat this argument, it is imperative that your lawyer prove the medical basis for your ongoing symptoms and to present the necessary evidence to prove you are truly suffering.
In my next blog I will discuss what I do as your attorney to prove that your post concussion symptoms are real.