Diagnosing ALS and learning about the disease process

Today, there is no current test that is done to diagnosis Amyotrophic Lateral Sclerosis, and the disease is very hard to diagnose. Only through a thorough clinical examination and series of diagnostic tests, that help to rule out other diseases that may mimic ALS, can be done to establish the disease.
The presence of upper and lower motor neuron signs is strongly suggestive to ALS. Once these are evaluated by the physician, they can order a series of tests to help eliminate other diseases and further suggest the diagnosis of ALS. Some of these tests are listed below.

• Electrodiagnostic tests including electomyography (EMG) - a special recording technique that detects electrical activity in the muscles
• Nerve conduction velocity (NCV) which measures electrical energy by assessing the nerve's ability to send a signal
• Blood and urine sample studies include high resolution serum protein electrophoresis, thyroid and parathyroid hormone levels and 24-hour urine collection for heavy metals
• Spinal tap
• X-rays, including magnetic resonance imaging (MRI) to get detailed images of the brain and spinal cord. These could reveal evidence of other problems that may be causing the symptoms, such as a spinal cord tumor, a herniated disk in the neck that suppresses the spinal cord, or even a cyst in the spinal cord.
• Myelogram of cervical spine - an imaging test that looks for problems in the spinal canal, including the nerve roots and other tissues.
• Muscle and/or nerve biopsy,
• Thorough neurological examination

There are several diseases that share the same symptoms of ALS and are all treatable. The ALS association recommends that patients diagnosed with ALS receive a second opinion from an "ALS expert" - someone who diagnoses and treats many patients with ALS and has training in this medical specialty.

The ALS Association. (2010, January 1). Diagnosing ALS. Retrieved January 30, 2015, from http://www.alsa.org/about-als/diagnosing-als.html

Etiology of ALS, and putting another face to the name.

In nine out of ten diagnoses of ALS, no clear identifying cause is apparent. Diagnosed patients lack an obvious genetic history, complete with affected family members. Nothing about the way patients live their lives have given scientists and clinicians clues as to what causes ALS. There is only a small, 5-10% of cases of ALS is familial. The term "familial ALS" means that there is more than one occurrence of the disease in the family. 

ALS occurs rarely and spontaneously, and has a median survival of 3 years after diagnosis. This motor neurodegenerative disease progresses in stages. It announces itself with persistent weakness or spasticity in one are or leg, causing difficulty using the affected limb. Some patients' first incidences have occurred with no warning, falling fast face first while walking during the day. Sometimes the motor problems originate in the muscles that control speech and swallowing. Hearing, vision, and touch generally remain normal, but voluntary movements of skeletal muscles can rapidly decline. 

In middle stages of the disease, motor symptoms progress from their starting point to the rest of the body, until it demands to be attended to. Some muscles may become paralyzed, while others are weakened or unaffected. Weakness in swallowing muscles may cause choking or difficulty eating and managing saliva. Weakness in breathing muscles can cause respiratory insufficiency, especially when lying down. Treatment can extend the length and meaningful quality of life for patients.

In the late stages of ALS, the symptoms have progressed immensely, and eventually lead to death. Most voluntary muscles are completely paralyzed. Muscles that help move air in and out of the lungs become diminished, and patients can need ventilatory support. Speech, eating or drinking may become impossible. New technology, like the computer that was talked about in the first post, may be used to help patients communicate through a speaking computer program. 

The end of this post will leave another face to the name of ALS, showing the true progression of this rapid  terminal disease. Steve Gleason, a former NFL football player, has been interviewed about his new journey in living. When Gleason was originally diagnosed, his providers truthfully told him to prepare to die, as this terminal illness has no medical cure. In response, Gleason said that he would instead "prepare to live." 

Stages of ALS. (n.d.). Retrieved January 23, 2015, from http://mda.org/disease/amyotrophic-lateral-sclerosis/signs-and-symptoms/stages-of-als

Epidemiology of ALS

Now that we have a foundational understanding of what Amyotrophic Lateral Sclerosis is, this week we will analyze the frequency and distribution of ALS and learn about the specific populations that this disease effects. Many studies have been done and articles have been written on ALS, but in the last five years, a few resources that had overlapping statistics seemed to be most reliable. 

By learning about the epidemiology of the disease, we can educate more people about its prevalence and help people recognize early symptoms and seek treatment and therapy as early as possible. Knowing which populations the disease is most prevalent in can also give certain people a good idea of who to look out for in regards to ALS.

What is the distribution in the US? 

There is a prevalence of 3.9 per 100,000 persons in the US general population, and an incidence of 1.89 per 100,000 per year are diagnosed. Prevalence and incidence are different from each other, where prevalence pertains to known existing cases of ALS, while incidence pertains to the number of new cases diagnosed each year.

Are certain parts of the population more affected than others? 

ALS occurs throughout the world with no racial, ethnic or socioeconomic boundaries. However, overall, ALS is more common among white males (twice as likely African-Americans), non-Hispanics, and persons aged 60-69 years. 

Males have a higher prevalence rate of ALS than females overall (1.5:1).

Age groups with lowest number of persons with ALS were 18-39 years of age and >80 years. Some physicians report that they are seeing "increasing numbers of younger ALS patients," these reports need more study. 

What is the mortality and morbidity from this disease?

Mean age of onset for sporadic ALS is about 60 years. Paralysis is progressive and leads to death d/t respiratory failure within 2-3 years  for bulbar onset cases and 3-5 years for limb onset cases.

About twenty percent of people with ALS live five years or more and up to ten percent will survive more than ten years and five percent will live 20 years. There are people in whom ALS has stopped progressing and a small number of people in whom the symptoms of ALS reversed.

Studies have shown that 70% to 90% of patients diagnosed as having ALS had this condition recorded on their death certificate.

The ALS Association. (2014, January 1). Epidemiology of ALS and Suspected Clusters. Retrieved January 1, 2015, from http://www.alsa.org/als-care/resources/publications-videos/factsheets/epidemiology.html

Mehta, P., Antao, V., Kaye, W., Sandez, M., & Williamson, D. (2014, July 25). Retrieved January 13, 2015, from http://www.cdc.gov/mmwr/preview/mmwrhtml/ss6307a1.htm

Wijesekera, L. C., & Leigh, P. N. (January 01, 2009). Amyotrophic lateral sclerosis.Orphanet Journal of Rare Diseases, 4.

Meet Stephen Hawking, the man behind "The Theory of Everything"

This past November, "The Theory of Everything" premiered in theaters, a film that moved audiences to tears as they took a journey through the life of Stephen Hawking, a world-renowned theoretical physicist and cosmologist of our time. It was not his baffling genius or ground-breaking research that moved audiences, however; the emotion of the movie was driven by the devastating turn his life took when he was diagnosed with Amyotrophic Lateral Sclerosis (ALS) at the young age of 21.

ALS is a progressive neurodegenerative disease that affects nerve cells in the brain and spinal cord. The advancement of the disease slowly destroys motor neurons, eventually leading to their death. With compromised motor neurons, the brain's ability to initiate and control movement in the body is lost, and as the disease progresses, individuals can become fully paralyzed.

Hawking, pre-diagnosis of ALS.

 Hawking, years after his diagnosis, physically limited to a motor chair but still able control facial muscles, enabling his speech and various facial expressions.

Today, Hawking is 73 years old, and communicates through a computer speaking device. A small sensor is activated by a muscle in his cheek. This sensor helps him "type" characters and numbers in his keyboard. The incredible computer technology learns to predict words and phrases for Hawking reducing the time and effort it takes for him to communicate. Hawking can give lectures, write chapters of books, and engage in conversations with the help of his technology.

This blog will aim to break down a general understanding of ALS week by week. Although Hawking's condition gives us a small picture to build our understanding of this terminal illness, we must keep in mind that as the longest living survivor of ALS, his condition and survival rate is especially rare. Unfortunately, life expectancy for individuals with ALS averages 2-5 years after the initial diagnosis.