Parkinson's Disease, Dementia, Neck Injuries and Sports
Parkinson's disease and dementia have long been associated with head injuries and concussions in sports, particularly boxing. In aging boxers it was called pugilistic Parkinson's disease or pugilistic dementia. (The word pugilistic has it's origin in Latin and means the skill, practice and sport of fighting with the fists.)
Studies have shown that head injuries are associated with increased levels of beta secretase in the brain. This is interesting because the enzyme beta secretase causes the formation of amyloid plaques in Alzheimer's disease. But there is still no clear mechanism as to how head injuries early in life can cause the brain to degenerate, oftentimes decades later, long after the injury. What has yet to be considered, however, is the impact of head injuries on the upper cervical spine and base of the skull. The impact of neck injuries on the brain and cord may not show up until years later.
Pugilistic PD affects far more than just boxers. It affects many athletes in many different sports where the neck is susceptible to injuries. Furthermore, it affects far more than athletes. If affects people involved in motor vehicle accidents and other injuries as well. For example, a similar controversy continues to surround the role of trauma in multiple sclerosis. For further information see the section on multiple sclerosis and trauma discussed on the ms lesions page.
When it comes to neck injuries, it doesn't matter whether it happens as a result of a car accident or sports, the mechanism of injury is relatively the same. Colloquially, it's called whiplash. Left untreated, whiplash types of injuries to the neck can have long-term affects on the health of the brain and cord that go undetected for many years.. They show up in advanced years when the affect of aging causes the stronger structures of the bones, cartilage and connective tissues to break down.
As is the case for most neurodegenerative diseases, the cause of primary Parkinson's disease (PD) and Alzheimer's disease (AD) is still unknown. One cause that has yet to be investigated is normal pressure hydrocephalus or NPH. NPH causes cerebrospinal fluid (CSF) volume to increase in the brain. If it accumulates in the cisterns (within the brain) and rises to the level of the pontine and more superior (higher) cisterns it has the potential to compress the midbrain. This is important because the midbrain contains the substantia nigra which is where the neurotransmitter dopamine is produced. Interestingly, a variant form of PD called mutli system atrophy is associated with atrophy of the midbrain. One of the most likely causes of NPH is injury to the upper cervical spine.
A poster celebrity advocate for Parkinson's disease is the former legendary boxing champion, Mohammed Ali seen in the picture above. By today's standard's Ali was a light heavy weight being under two hundred pounds when he was in his best condition. He was less built up and less encumbered by bulky red muscle fibers from lifting weights. Instead, he was loaded with high speed white twitch muscle fibers. His atheletic prowess was incredible. When it came to red muscles, he had phenomenal cardiovascular endurance and used it to his advantage. He was fast and light on his feet and could bob, weave and duck in the blink of an eye, which made it hard for opponents to land blows.
Most of Ali's opponents were mighty powerful men and despite his prowess he got hit hard many times. It got worse as he got too old but continued to fight. He was well past his prime and surviving strictly on his vast experience fighting some of the toughest and best opponents in the sport. His former skills and fitness had declined considerably. The severe blows to the head continued to add up. In some cases he was lucky just to come out of the fight alive.
The knockout punch in boxing is called the cross punch. Typically the lead hand jab sets up, distracts and obscures the cross punch. In contrast to the picture of the south paw (left handed in gold shorts) fighter below, the cross punch is usually thrown from the rear hand and foot, which is the right hand in most people. It is a long punch because the hips and shoulders twist and extend the reach. The twist of the hips and shoulders increases the power of the punch significantly.
More importantly, as in the picture, it's called a cross punch because it crosses over the lead arm of the opponent and strikes him broadside on the face, thus crossing the opponents body. The cross punch violently snaps the upper cervical spine in a side bending and rotation movement. It's the best way to knock an opponent out because it causes a mini stroke that temporarily cuts off blood flow to the brain. But the damage goes much further than a mini stroke. It can also damage the upper cervical spine soft tissue. Over time, damage to the upper cervical spine can lead to NPH.
Boxing is not the only sport to pose significant risk to head and neck injuries that could lead to Parkinson's disease. Many sports cause similar injuries to the cross punch. Ice hockey is one. Getting your face slammed into the sideboards from a body check, likewise, snaps the upper cervial spine. In this regard, celebrity actor Michael J. Fox, founder of the Fox Foundation for Parkinson's Research, is a former avid hockey player. His problems with Parkinson's started as a tremor in his pinky and arm. Previously, he was checked hard at least once, as I recall, where he was thrown into the sideboard and momentarily knocked out.
Wrestling and football are also notorious sources of head and neck injuries. When they cause neurological damage the affects are often immediate and easy to recognize. Injuries to the bones, cartilage and connective tissues of the spine, on the other hand, can be much more subtle and difficult to detect because the tissues breakdown slowly over years causing delayed onset in signs and symptoms. By the time they show up the injury has long been forgotten and no longer a suspect.
What is worse, and truly irresponsible, is knowing what we know about head injuries and neurodegenerative diseases in male athletes, we have encouraged females to play the same risky male sports. Females have smaller, thinner bones in the skull and spine compared to males with smaller openings and dimensions for blood vessels and nerves. This makes them more susceptible to compression of neurovascular tunnels from bone, cartilage and connective tissue breakdown. Moreover, even the most hardened highly accomplished and fit female athletes have much smaller neck muscles making them far less capable of resisting whiplash type forces, such as from cross punches to the face.
Most men aren't built for years of constant blows to the head either. Ideally, the best type of neck for boxing and wrestling would be built like an ape. Just look at the size of the neck in the ape and compare it to the more delicate human design. In other words, the best neck for humans participating in these sports would be short and thick with no visible neck similar to the famous boxer George Foreman or a football lineman. The next best defense is to build up the neck muscles. But even big bulky neck muscles offer only limited protection against whiplash forces. They offer far less protection against side bending and rotation that strain, twist and snap the upper cervical spine. Compared to most mammals, the cervical spine in humans is particularly weak by design due to upright posture. What's more, even necks built like tree trunks like the boxers above, fall to forces that catch them off guard.
In addition to athletic sports, recreational all terrain and snowmobiles have added more injuries to the growing list. This may explain the recent rise not only in Parkinson's, but early onset Parkinson's disease as well.
The spine, especially the upper cervical spine, is critical to the health of the brain and cord. There is a reason why neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease and multiple sclerosis, show up later in life in the order that they do. The spine doesn't degenerate overnight. It occurs over many years.
Aside from trauma, simply aging causes the bones, cartilage and connective tissues of the spine to slowly breakdown and degnerate over the course of a lifetime. No one is immune. Athletic injuries simply compound and accelerate the process. Over time, injuries to the spine can affect the brain and cord and result in neurodegenerative processes and subsequent diseases such as Alzherimer's, Parkinson's and multiple sclerosis.