Primary progressive aphasia (PPA) is a neurological effect specifically associated with certain types of dementia (Alzheimer’s Disease and frontotemporal dementia are the most common underlying forms of dementia in which PPA occurs) that results in linguistic abilities becoming slowly and progressively impaired until they are completely gone.
Most dementias – Lewy Body dementia, vascular dementia, early-onset dementias, alcohol-related dementia, and Alzheimer’s Disease among them – appear seemingly suddenly as primary and distinct neurodegenerative processes without definitive causes (except in the case of genetic inheritance, which primarily occurs in rare dementias like Corticobasal Degeneration, Progressive Supranuclear Palsy, and Fatal Familial Insomnia and some of the early-onset dementias).
However, there are a group of neural disorders, which are caused by the same genetic mutation that affects lipid storage in the body, that often have dementia as a secondary symptom as the diseases progress.
These neural disorders (all these have sphingolipid metabolism dysfunction in common) – which include Niemann-Pick disease, Tay Sachs disease, and Gaucher disease – are characterized by by increased levels of a particular type of sphingolipid.
There is no cure for these neural disorders and they are all fatal (in many cases, during childhood).
Spingolipids are the biological product of a chemical process that creates a protective layer on nerve cell membranes and ensures proper – and protective – cell signaling and are critical to optimal brain function.
The genesis of sphingolipids are long-chain – also known as sphingoid – bases that normally have a length of 18 carbons, although they can also have lengths of 16 or 20 carbons. The length of long-chain bases is determined by serine palmitoyltransferase (STP), a multiprotein enzyme.
In neural disorders like Niemann-Pick disease, Tay Sachs disease, and Gaucher disease, a mutation (known as Stellar) in one of the proteins that makes up STP creates an abnormally high number of 20 carbon long-chain bases, which dramatically interferes with sphingolipid metabolism.
This causes neurodegeneration to occur. In all these neural disorders, much of the neurodegeneration begins soon after birth.
In Tay Sachs disease, neurodegeneration of the brain and spinal cord begins at about six months of age. The average lifespan is four years.
Gaucher disease has three subtypes.
In Type 1 Gaucher disease, symptoms, which include anemia, bone deterioration, and liver and spleen impairment, are non-neurological and do not materialize until middle age. The average life expectancy for Type 1 is 68 years.
Type 2 and Type 3 Gaucher disease are both neuropathic forms of the disease. Neurodegenerative symptoms include abnormal eye movements, seizures, and systemic brain damage.
In Type 2 Gaucher disease, the onset of symptoms is within three to six months of age. Deterioration is rapid; the average life expectancy is about two years of age.
Type 3 Gaucher disease is a slower onset and involving version of Type 2. The average onset of neurological involvement is late childhood into adolescence. Life expectancy ranges from the mid-twenties to, in extremely rare cases, the early forties.
Niemann-Pick disease has four types: Type A, Type B, Type C1 and Type C2.
Niemann-Pick disease Type A occurs in infants. Symptoms include enlargement of the liver and spleen (around three months of age) and a failure to thrive during the first year of life. At one year, widespread damage to the lungs occurs, and there is a progressive loss of neurological and motor function.
Along with Tay Sachs disease, Niemann-Pick disease Type A also has a common eye deformity consistent with neurometabolic disease, known as a cherry spot, that occurs within the macula and is often what initially identifies the two neural disorders.
While most children born with Niemann-Pick disease Type A die in infancy, a few may live as long as four years.
Niemann-Pick disease Type B includes most of the same symptoms as Type A (motor skills are not usually affected), but the onset of symptoms is during adolescence. Most people with Niemann-Pick disease Type B survive into adulthood, but mortality rates climb dramatically between twenty and thirty years of age.
Niemann-Pick disease Type C (C1 and C2 are caused by different gene mutations, but the symptoms are the same) is characterized by severe liver disease, severe pulmonary infections, progressive neurodegeneration, and increasing difficulty with speech and swallowing that deteriorates completely over time.
The onset of Niemann-Pick disease Type C can be at any age, but it is most commonly seen by the age of five. The life expectancy with this type is under twenty years of age when symptoms appear in childhood. When symptoms appear later, the life expectancy is ten to twenty years after symptoms begin.
Our brains are very soft organs that are surrounded by spinal fluid and are protected by the hard outer covering of our skulls.
Under normal circumstances, spinal fluid cushions the brain and keeps it from crashing into the skull. However, if our heads or our bodies are hit hard, our brains can slam into our skulls and result in traumatic brain injuries (TBIs). TBIs are also caused when the skull is fractured and the brain is directly damaged by outside force.
Although concussions, which we’ll discuss later, are sometimes referred to as mild TBIs, the reality is that no injury to the brain is mild and repeated injuries will lead to neurological degeneration that includes dementia.
TBIs are complex neurological injuries that result in a wide variety and severity of symptoms and disabilities.
The least severe symptoms of TBIs – and these may not happen immediately and, in fact, may occur some time after the injury, can include:
- Temporary loss of consciousness
- Slurred speech
- Temporary memory loss
- Grogginess and sleepiness
- Double vision or blurred vision
- Nausea or vomiting
- Sensitivity to light
- Balance problems
- Slow reaction to stimuli
The most severe symptoms of TBIs can include:
- Extended loss of consciousness or coma
- Permanent and severe brain damage
- Partial or complete motor paralysis
- Falls (40.5%)
- Car accidents (14.3%)
- Head/body collisions with people or things (15.5%)
- Assaults (10.7%)
In the category of TBIs from falling, most of the falls occur disproportionately in the very young (55% of falls among children occur in children between the ages of 0 and 14) and the very old (81% of falls among adults occur in adults who are 65 or older).
Most of the TBIs in the Other category (19%) are from personal firearms and military weapons.
A type of TBI that is more frequently in the headlines today is Chronic Traumatic Encephalopathy (CTE). CTE is brain damage that occurs as a result of repeated concussions (a concussion is defined as injury to the brain from a direct blow to the head or from the head or upper body being violently shaken).
The first identified variant of CTE was described in 1928 by forensic pathologist Dr. Harrison Stanford Martland as pugilistic (from the Latin word pugil, which is translated as “boxer” or “fighter”) dementia. The symptoms included tremors (Parkinsonism), slowed movement, mental confusion, and speech difficulties.
In 1973, the neuropathology of pugilistic dementia was discovered and described by a team of pathologists led by J. A. Corsellis who documented their findings after performing thorough autopsies on the brains of 15 deceased boxers.
By the age of 18, he had boxed his way to the heavyweight gold medal at the Olympics (1960).
A few months later Ali began his professional boxing career. He quickly gained national prominence because of his skill in the ring and his trademark quote: “Float like a butterfly, sting like a bee. The hands can’t hit what the eyes can’t see.” He boxed professionally until his retirement in 1981.
His wife, Lonnie, is his caregiver and contributed to a moving article that AARP published last year about what she and Ali deal with on a daily basis as a result of the neurological degeneration that CTE has caused.
CTE has increasingly become a major health concern in the high-contact sports of professional wrestling, ice hockey, soccer, and football as more and more current and retired athletes are showing symptoms consistent with CTE.
In recent years, football – and especially professional football – has become the focal point for a closer examination of CTE. Not only has this sport become more violent in terms of how the game is played, but how concussions are treated – or not treated – has also come under greater scrutiny.
Although NFL team doctors assert that CTE is “rare” or “overexaggerated,” the hard scientific neurological and physiological evidence proves that these doctors are simply paid hirelings who care more about their paychecks than they do about the overall health of the players.
Let’s examine the facts. In a 2014 landmark study by the largest brain bank in the United States, 76 of the 79 brains of deceased NFL players that pathologists examined had TBI, and specifically, CTE.
A class action lawsuit has been filed – and a tentative agreement reached with the NFL – by retired NFL football players and/or their families (some of the players have already died from neurodegenerative causes) which claims that players were not (a) adequately protected from suffering concussions, (b) medically treated properly following concussions, and (c) provided adequate medical compensation to treat the burgeoning costs of CTE as it progresses.
This gist of this lawsuit is that the NFL used – and abused – these players to fabulously guild the seemingly-endless coffers of the NFL, often forcing the players by intimidation or fear to get back on the field as soon as they could after suffering a concussion (often in the same game), and then abandoned their responsibility to their former employees (as part of their contractual agreement) as soon as the employees began costing them money instead of making them money.
Even more damning to the NFL is the actuarial report accompanying the lawsuit that indicates that at least 1/3 of NFL players will suffer CTE.
If there is a silver lining in all of this, it is that the younger NFL players have a much greater awareness of the relationship – and their increased risk – between professional football and CTE.
They are aware of the very real probability that they will be one of the 1 out of every 3 players who develops CTE.
And they’re choosing their long-term health, including their brain health, over temporary fame and fortune.
- Cortland Finnegan – Age 31
- Jake Locker – Age 26
- Jason Worilds – Age 27
- Chris Borland – Age 24
While Finnegan, Locker, and Worilds did not publicly cite CTE as a factor in their premature retirements from the NFL, there can be no logical reason to doubt that the mounting evidence was a factor in their decisions.
Borland just finished his rookie season (2014-2015) with the San Francisco 49ers, but he revealed after the season that he suffered a concussion in training camp last fall. Instead of reporting the concussion, Borland covered it up so that he could continue to practice and win a starting position on the team.
This is the kind of competitive pressure that gets put on these young players by the NFL (yes, Borland made the decision and he bears the responsibility for it, but had he reported the concussion, he would have been replaced and lost the starting spot and may not have played all season).
Fortunately, though, Borland came to his senses and realized how much he had jeopardized – and would continue to – his neurological health.
As he said on the March 16, 2015 edition of ESPN’s Outside the Lines, “”I just thought to myself, ‘What am I doing? Is this how I’m going to live my adult life, banging my head, especially with what I’ve learned and knew about the dangers?'”
We can only hope that more athletes in high-contact sports will know the higher risks of TBIs they face, not just in the professional leagues, but at the amateur levels, and they will choose to walk away from certain neurological damage.
In the meantime, we have a better understanding just in our daily lives of how TBIs can happen and what the results can be, so I hope that we’re a little more observant and attentive after falls with our little loved ones and our older loved ones, especially those already going through the journey through dementias and Alzheimer’s Disease, as they are even more prone to falling than the general elderly population.
As Sergeant Phil Esterhaus says at the end of every roll call on Hill Street Blues (a favorite TV show of mine during my high school and college years), “Hey, let’s be careful out there.”