Post-Concussion Syndrome (PCS)


Image 1- http://www.weheartbrain.com/what-is-a-concussion/post-concussion-syndrome/
Image 1- http://www.weheartbrain.com/what-is-a-concussion/post-concussion-syndrome/

Introduction

Post-Concussion Syndrome (PCS) has recently gained much attention due to new research in head related injuries. PCS is a debilitating lingering injury from one or more concussions with concussion symptoms that can last several months to years before recovery. Symptoms can vary from patient to patient. Each concussion will differ depending on the individual and the severity of the injury. Common symptoms include headaches, balance problems, psychological problems, and other difficulties pertaining to head trauma. Treatment is limited, but most individuals will fully recover after a period of time. Few people have persisting symptoms that last their whole lives. More research has been fueled by the increasing awareness of concussions. Better equipment, treatment, therapy, and diagnosis has improved patient outlook, but research has seemed to just scratch the surface of PCS ("Wikimedia," 2012).
For more insight on concussion see:
http://kin450-neurophysiology.wikispaces.com/Concussions
Another short overview of PCS:
http://rklperry3.wikispaces.com/Post+Concussion+Syndrome

Functional Anatomy Of Common Concussion Symptoms


It can be difficult to determine the location of a concussion injury because the brain is so interconnected. It is important to understand the anatomy and physiology of individual symptoms when dealing with PCS. Symptoms can widely vary, but there are a few common symptoms that appear with most people suffering from PCS.

Headaches/Migraines

Frustratingly, doctor do not have a definitive explanation as to why migraines occurs with concussions. It is hard to examine a living brain under the condition of a concussion, but educated speculation provides meaningful explanations. Most concussions investigated under MRI will show no visible difference from a healthy brain unless there are moderate contusions on the brain. In this case, there will most likely be blood leaking from the damaged vessels. If a shearing injury occurs, meaning a sliding of the brain against its different surface (ex: dura mater against the grey matter), then axonal damage of the neurons will occur. This damage most often causes a disruption of the signal which can lead to chronic headaches until the injury is healed. Axonal injury can occur anywhere, but it typically happens in the lateral, superior, anterior and posterior portions of the brain. The inferior portion seems to be more protected, simply because of it location. Sometimes an especially hard blow will cause a contra coup injury. This occurs when the opposite side of the brain is also injured by the brain bouncing back after the initial blow. If the axon is damaged enough it could result in permanent brain damage. Most often the damage will be on a microscopic level, not seen on an MRI. Experts believe that blood flow on a microscopic level is obstructed and a chemical imbalance is telling the body that something is wrong, thus causing a migraine (typically behind eyes). At the initial hit, the neurons depolarize, releasing neurotransmitters causing post-synaptic receptors to activate. Calcium ions flood the cells telling another messaging system to release letting the body know that there is cell damage and to respond with inflammation. After the initial blow, the brain is disrupted chemically (free radical accumulation), and cannot code DNA correctly. Persisting, unrelenting or activity inducing headaches are a cardinal sign of PCS. Interestingly, headaches will spontaneously disappear after a period of time passed (Anderson, Heitger & Macleod, 2006). (entire paragraph)


Image 2: http://www.docgrimes.com/journal/2011/10/19/concussions-and-post-concussion-syndrome.html
Image 2: http://www.docgrimes.com/journal/2011/10/19/concussions-and-post-concussion-syndrome.html



Dizziness, Unsteadiness & Imbalance


Another common symptom is the ambiguous term "dizziness" or unsteady balance. Dizziness can be defined as "the painless head discomfort with many possible causes including disturbances of vision, the brain, balance (vestibular) system of the inner ear, and gastrointestinal system" ("Definition of dizziness," 2011). The vestibular system controls much of the body's balance with the otolithic organs and the semi circular canals. Since the vestibular system is located in the inner ear, it can be damaged by a blow to the head. There are three semi circular canals attached to the saccule and utricle. As the head rotates, fluid rushes either toward or away from the stereocilia in a gel material called the cupula, causing either an excitatory or inhibitory response declaring where the head is in space (Grey). Another feature of the vestibular system is the otolithic organs located in the utricle and saccule. Otolithic rocks, calcium carbonate, are on top the gelatinous material and slide as the head and body move, pulling the cilia to excite and signal that the body is moving (Grey). The 8th cranial nerve connect the vestibular system to the brain. Most of the vestibular afferents signals travel to Scarpa's ganglion. Its axons travel in the 8th cranial nerve and attach to the 4th cranial nerve, traveling to the vestibular nuclei located in the rostral medulla and part of the caudal pons. A small amount of vestibular afferent signals travel straight to the cerebellum but first pass through the inferior cerebellar peduncle. The cerebellum is closely tied to the vestibular system and injuries to he cerebellum can cause dizziness too (Grey). The vestibular system also contributes to eye movements. Many times an otolithic rock will dislodge and find itself in a semicircular canal. This is called Benign Paroxysmal Positional Vertigo (BPPV). With BPPV, dizziness will occur when the head is placed in a certain position. Its can be easily resolved using certain maneuvers by a trained therapist. Real problems occur when pathways between the brain and/or the vestibular areas of the brain become damaged. Studies on dizziness have shown that patients who experience dizziness are likely to have a longer recovery than patients who do not experience dizziness. More follow up studies need to be done, but dizziness is a serious factor that can involve several different parts of the brain, because it is such a sensitive and key part to the body.

Memory/Emotions


Other major PCS Symptoms are related to cognitive function of memory and changes in mood stability. Most of these activities happen with in the hippocampusand limbic regions of the brain. The hippocampus stores recollection memory, helps remember how to get places, and generates emotional responses.
Signals travel into and through the hippocampus in three ways. First, "the perforant pathway from the entorhinal cortex to granule cells of the dentate gyrus. Second, the mossy fiber pathway goes from the granule cell of the dentate gyrus to the pyramidal cells of the CA3 region of the hippocampus. Lastly, the Schaffer collateral pathway moves from the CA3 region of the hippocampus to the CA1 region of the hippocampus (Grey)." Figure 10.5better shows the pathway about the hippocampus. This hippocampus is located deep within the brain and damage to this structure may be some of the reason for emotional and mood instability with PCS patients. Because the hippocampus is closely related to emotions, it is thought that damage to this structure and the amygdala is what gives some PCS patients an apathetic nature as well as generalized depression (Grey). The amygdala is associated with strong emotions and without it, decision making is generally more difficult because emotions and risk factors cannot be weight appropriately (Dewey, 2007).

Some further readings on limbic function related to PCS:
http://neuroscience.uth.tmc.edu/s4/chapter05.html
http://neuroscience.uth.tmc.edu/s4/chapter06.html

PCS Management/Treatment

The only real way to combat PCS is to limit extra brain activity as much as possible. One must use his/her symptoms to gauge the amount of physical and mental activity that their body can handle without delaying the healing process. Management of PCSis very important when easing back into activity. A second impact to the head while recovering could be detrimental, worsening symptoms and possibly causing permanent damage. Thus, it is extremely important to for patients recovering from PCS to stay away from activity, and guidelines must be set. Rest is the most important medication when dealing with PCS. Resting means taking time away from electronics, exercise and brain altering substances like caffeine, alcohol, pain killers and smoking. The rule of thumb when it come to management of PCS: Any activities that induce PCS symptoms should be avoided. With that said, some individuals may be able to partake in activities that others cannot. It depends on what produces symptoms in the individual. All of these things will impede recovery and some can even cause long-term damage. Not much research has been done to see if substances like alcohol prolong healing. However, alcohol and substances similar to it, are neurotoxins which directly effect the brain and how it functions. Since the brain is already injured with PCS, drinking and drug use can be harmful because of their affects on the brain. It is commonly known to not drink excessively or use drugs because it is compromising one's health. Doctor's can only place more stress on how important it is to not ingest neurotoxins when concussed. Electronics should be kept to a minimum because it stimulates the brain, causing headaches and not allowing the body to recovery due to stimulation. As mentioned, it is important to monitor your symptoms before activity and at rest. Once the patient has a good understanding of their symptoms and is progressing naturally (progression that is not masked by drugs or pharmeucutical symptom reducers), they may begin to increase activity. A regulated progression to activity must be monitored by a physician. This must be gradual and the patient must be symptom free at rest before participating in activities. Once beginning activities, symptoms should be monitored and individual is advised to stop when/if symptoms emerge. Once symptoms become less frequent and subside, the individual can progress and return to normal activity.
Symptoms can be subdued by medication, but may have adverse side effects. The most common head ache reliever and depression medication is amitriptyline (table 3, page 8, Anderson, Heitger & Macleod, 2006). Doctors are uncertain why it treats PCS head aches, but it is thought that it chemically balances the brain. In order for amitriptyline to work it must be taken regularly. Side effects are commonly dry mouth and fatigue/drowsiness ("Amitriptyline-pubmed health," 2010). Another common pain reliever used in PCS patients is acetaminophen because it is not a blood thinner. Blood thinning medications are not advised to be taken because it could prevent the brain from clotting and continually bleed.("How do medications,") Lastly, Omega-3 fatty acid capsules (fish oil supplements) have recently been proscribed by doctors in high doses. It is commonly known that Omega-3's assist brain activity, and some patients have found symptom relief while on high doses of Omega-3 fatty acid supplements. ("Omege-3 information ," 2012) As mentioned PCS is different for each suffering person, and sometimes finding the right medication with minimal side effect be trial and error.
Further reading on non-pharmacuetical approach to PCS management:
http://ihealthnow.org/documents/PCS_Natural_Final11152011.pdf
Further guidelines for returning to play for Concussions and PCS:
http://www.youtube.com/watch?v=W31cB7XU1A4&feature=related

Conclusion

In conclusion, PCS can be be avoided if patients take time to recover properly from initial blows to the head. However, since all concussions are different, severity seems to be the deciding factor in the occurrence of PCS. Injury to different regions of the brain can produce certain symptoms, but it is difficult to pinpoint the exact location of the injury. Many times there is no exact injury, but a broad range of injured regions due to the nature of concussions. Many times it can be difficult to determine how severe the concussion is until time has passed and symptoms linger. Based on tests and guidelines, individuals should resist brain-stimulating activities and abstain from neurotoxic ingestion. Rest and modulated progression are the primary treatment techniques when recovering from PCS. It is important to maintain honesty with symptoms, otherwise healing will be prolonged and further damage could occur. There are few medications that provide symptom relief, but side effects discourage long term use. Every PCS case is different and PCS should not be generalized from patient to patient. PCS is a growing concern and should not be taken lightly because of the long term implications link to cerebral disease.

Glossary of Terms

shearing injury (contracoup) - also known as axonal shearing injury, in which the brain hits against the skull and again on the opposite side causing the axon to "shear or damage
dizziness - unsteadiness, imbalance, feeling of being light headed
vestibular system - controls the head and body's orientation in space as well as eye movements and balance
Benign Paroxysmal Positional Vertigo - experiencing vertigo when it comes to position specifically due to a dislodged otolithic rock in a semicircular canal, it is benign and can be eliminated with certain maneuvers.
Hippocampus - seahorse shaped portion of the brain, that contributes to memory and emotion
Amygdala - part of the limbic system, helps control mood and emotions (Grey)
amitriptyline- is a tricyclic antidepressants, that is used to treat depression and post-concussion symptoms, mostly off-label for head aches and depression ("Amitriptyline-pubmed health," 2010)
Omega-3 fatty acids - unsaturated fat that can be derived from certain fish, fruit, vegetables and grains and is used to fight inflammation and improve brain function
neurotoxins- it is a potentially harmful substance, that effects the nervous system ("Neurotoxin ," 2012)

Quiz Questions (and Answers)

True or False

  1. T or F MRI's will always show where damage is after receiving a concussion.
  2. T or F Dizziness has been shown to increase recovery time
  3. T or F Drinking alcohol should be avoided when concussed.

Multiple Choice (also from extra readings)

  1. In regards to the vestibular system where do most of the afferent signals travels to? a. Hippocampus b. Amygdala c. Scarpa's Ganglion d. none of the above
  2. Which of the following could be unsafe to do while suffering from PCS? a. drink alcohol b. exercise c. go to the movies d. all of the above are correct
  3. When suffering a third concussion on one season what should the protocol be? a. terminate season b. wait one week or till symptoms dissapear c. if the player can remember basic this then he/she is ready to play again d. there is no protocol

Short Answer

  1. Describe the vestibular function.
  2. What is the rule of thumb when healing and monitoring PCS symptoms?
  3. Talk about the guildelines for suffering concussions each season and how one should return to play after a head injury.
  4. Reason why a contracoup head injury is so serious.
Answers in order: FTTcda

References (Finish rest of citation)

  1. Wikimedia. (2012, march 04). Retrieved from http://en.wikipedia.org/wiki/Post-concussion_syndrome
  2. Anderson, T., Heitger, M., & Macleod, A. D. (2006, November 23). Concussion and mild head injury. Retrieved from http://www.nzbri.org/research/publications/papers/0344.pdf
  3. Definition of dizziness. (2011, April 27). Retrieved from http://www.medterms.com/script/main/art.asp?articlekey=6114
  4. Grey, L. (n.d.). Vestibular system: Structure and function. Retrieved from http://neuroscience.uth.tmc.edu/s2/chapter10.html
  5. Grey, L. (n.d.). Vestibular system: Pathways and reflexes. Retrieved from http://neuroscience.uth.tmc.edu/s2/chapter11.html
  6. Grey, L. (n.d.). Limbic system: Amygdala. Retrieved from http://neuroscience.uth.tmc.edu/s4/chapter06.html
  7. Grey, L. (n.d.). Limbic system: Hippocampus. Retrieved from http://neuroscience.uth.tmc.edu/s4/chapter05.html
  8. Amitriptyline-pubmed health. (2010, August 01). Retrieved from http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0000666/
  9. Neurotoxin . (2012, March 15). Retrieved from http://en.wikipedia.org/wiki/Neurotoxin
  10. How do medications treat concussions?. (n.d.). Retrieved from http://www.sharecare.com/question/how-do-medications-treat-concussions
  11. Omege-3 information . (2012). Retrieved from http://www.dhaomega3.org/FAQ/Have-there-been-published-studies-showing-a-protective-effect-of-omega-3-in-PTSD-Post-Tramatic-Stress-Disorder-and-concussions
  12. Dewey, D. (2007). intropsych. Retrieved from http://www.intropsych.com/ch02_human_nervous_system/function_of_the_amygdala.html