Amyotrophic lateral sclerosis (ALS), often recognized as Lou Gehrig’s disease, is a neurodegenerative condition that progressively impairs motor neurons, the nerve cells vital for voluntary muscle control. At the ALS Program at Hospital for Special Surgery, a certified ALS Center of Excellence, we offer comprehensive care, including both in-person and telehealth services, alongside cutting-edge treatment research and clinical trials for this challenging disease. This article delves into understanding ALS, with a particular focus on life expectancy following diagnosis.
What is Amyotrophic Lateral Sclerosis (ALS)?
ALS is characterized by the degeneration of motor neurons, which extend from the brain through the brainstem and spinal cord to muscles throughout the body. These neurons are responsible for controlling movements in the arms, legs, chest, throat, and mouth. In ALS, the destruction of these motor neurons leads to muscle weakening and wasting. It’s important to note that ALS primarily affects motor functions, leaving sensory and cognitive functions intact.
ALS is generally classified into two types: upper motor neuron disease, affecting neurons in the brain, and lower motor neuron disease, impacting neurons originating from the spinal cord or brainstem. Regardless of the type, the outcome is the same – progressive damage and eventual death of motor neurons, making ALS a fatal condition.
ALS Life Expectancy: Time from Diagnosis to Death
When considering ALS, one of the most critical questions is about life expectancy after diagnosis. The average time from ALS diagnosis to death is typically two to five years. However, it’s crucial to understand that this is just an average. The course of ALS is highly variable, and some individuals live significantly longer.
Statistics show that approximately 50% of people with ALS live for at least three years post-diagnosis. Around 25% survive for five years or more, and encouragingly, up to 10% may live for more than ten years. There are even exceptional cases, such as the renowned physicist Stephen Hawking, who lived for over five decades after his ALS diagnosis, demonstrating the wide spectrum of survival times.
This variability in ALS survival time highlights the complexity of the disease and the influence of various factors, including the specific pattern of motor neuron degeneration, the individual’s overall health, and the quality of care received.
Symptoms of ALS and Disease Progression
The symptoms of ALS are diverse, reflecting the varied patterns of upper and lower motor neuron involvement in each individual. The initial symptoms, as well as the rate of disease progression, can differ significantly from person to person. Despite these variations, progressive muscle weakness and paralysis are universal experiences for those living with ALS.
As ALS progresses, more motor neurons are affected, leading to the deterioration of muscle tissue. This results in muscle weakness, atrophy (muscle wasting), and a thinning appearance of limbs. Paradoxically, muscles can also become spastic, leading to involuntary movements and increased muscle tone in certain areas of the body.
Early ALS symptoms are often subtle and easily overlooked. Common initial indicators include:
- Muscle weakness in hands, arms, or legs.
- Difficulty using arms and legs for everyday tasks.
- Muscle twitching and cramps, particularly in the extremities.
- Weakness in muscles controlling speech, swallowing, or breathing.
- Slowed or slurred speech (dysarthria) and reduced voice projection.
In advanced stages of ALS, breathing and swallowing difficulties become prominent and are often the eventual cause of death. Shortness of breath and dysphagia (difficulty swallowing) significantly impact quality of life and require careful management.
Unraveling the Causes of ALS
The exact cause of ALS remains largely unknown, but current research suggests a complex interplay of multiple factors leading to motor neuron death. While specific risk factors are still under investigation, genetics and environmental influences are considered potential contributors. Notably, research from 2009 indicates that tobacco smoking may increase the risk of developing ALS.
Several biological mechanisms are being explored as potential contributors to ALS, including:
- Defective glutamate metabolism: Glutamate is a neurotransmitter, and imbalances can be toxic to nerve cells.
- Free radical injury: Unstable molecules damaging cells.
- Mitochondrial dysfunction: Problems with the energy-producing parts of cells.
- Gene defects: Genetic mutations can play a role in familial ALS and possibly sporadic cases.
- Programmed cell death (apoptosis): Abnormal activation of cell death pathways.
- Cytoskeletal protein defects: Problems with the structural components of cells.
- Autoimmune and inflammatory mechanisms: The body’s immune system attacking nerve cells.
- Accumulation of protein aggregates: Clumps of proteins interfering with cell function.
- Viral infections: While less clear, some viral infections are being investigated.
It is increasingly recognized that specific gene mutations and inherited predispositions can modify disease susceptibility and progression, highlighting the genetic complexity of ALS.
Who is Affected by ALS?
ALS affects a diverse population, although some demographic patterns are observed. In the United States, approximately 60% of reported ALS cases are in men, and 93% of patients are Caucasian. US population studies indicate about 5,600 new ALS diagnoses each year, roughly 15 new cases daily. It’s estimated that around 30,000 Americans are living with ALS at any given time.
The onset of ALS typically occurs between ages 40 and 70, with an average age of diagnosis around 55. However, ALS can, in rare instances, affect individuals in their 20s and 30s, demonstrating that it can occur across a broader age range.
Diagnosing ALS: A Comprehensive Approach
Diagnosing ALS is a complex process, as there is no single definitive test. Furthermore, many neurological conditions share similar symptoms, necessitating a process of exclusion. A comprehensive diagnostic evaluation typically involves a combination of clinical examinations and medical tests to rule out other conditions.
The diagnostic workup for ALS often includes:
- Electrodiagnostic tests: Electromyography (EMG) and nerve conduction velocity (NCV) studies to assess nerve and muscle function in different regions (bulbar, cervical, thoracic, lumbar).
- Blood and urine studies: Including serum protein electrophoresis, thyroid and parathyroid hormone levels, and urine heavy metal analysis to exclude immunological or inflammatory diseases.
- Spinal tap (lumbar puncture): To analyze cerebrospinal fluid.
- Imaging studies: X-rays, magnetic resonance imaging (MRI), and CT scans, particularly of the cervical spine, to visualize the nervous system and rule out structural issues.
- Muscle and/or nerve biopsy: In some cases, to examine tissue samples.
- Thorough neurological examination: To assess motor function, reflexes, and sensory functions.
The specific tests performed are determined by the neurologist based on the individual’s symptoms, physical examination findings, and results of prior medical evaluations.
Current ALS Treatments and Management
Currently, there is no cure for ALS, and treatments cannot reverse the damage already caused by the disease. However, there are FDA-approved treatments aimed at slowing disease progression and improving quality of life.
Medications for ALS:
- Riluzole (Rilutek, Teglutik): Shown to modestly extend survival in some individuals with ALS.
- Edaravone (Radicava): May help slow the decline in daily functioning in certain ALS patients.
Multidisciplinary Care:
A cornerstone of ALS management is multidisciplinary care. Teams of specialists, including neurologists, pulmonologists, physical therapists, occupational therapists, speech therapists, nutritionists, and social workers, collaborate to address the multifaceted needs of individuals with ALS and their families. This team approach focuses on symptom management, maintaining independence, and enhancing quality of life. Studies have shown that multidisciplinary care can improve survival rates in ALS.
Assistive Devices and Therapies:
Various devices and therapies are crucial in managing ALS symptoms and maximizing functional abilities:
- Proper body positioning and support.
- Exercise regimens, physical and occupational therapy to maintain muscle strength and function as long as possible.
- Assistive devices for walking, mobility aids like braces, splints, and customized wheelchairs.
- Home modifications to improve accessibility.
- Communication technology to aid speech difficulties.
- Nutritional support and dietary modifications to ease swallowing, including feeding tubes when necessary.
- Respiratory support, including diaphragm pacers and breathing assistance devices.
Clinical Trials and Research:
Ongoing research and clinical trials are vital in the fight against ALS. Many individuals with ALS participate in research studies to test new medications and therapies. Resources like the US National Institutes of Health Clinical Trials Registry and the HSS ALS Program website provide information on current research opportunities.
References
- Dean KE, Shen B, Askin G, Schweitzer AD, Shahbazi M, Wang Y, Lange D, Tsiouris AJ. A specific biomarker for amyotrophic lateral sclerosis: Quantitative susceptibility mapping. Clin Imaging. 2021 Jul;75:125-130. doi: 10.1016/j.clinimag.2020.12.018. Epub 2021 Jan 4. PMID: 33548870.
- Shtilbans A, Choi SG, Fowkes ME, Khitrov G, Shahbazi M, Ting J, Zhang W, Sun Y, Sealfon SC, Lange DJ. Differential gene expression in patients with amyotrophic lateral sclerosis. Amyotroph Lateral Scler. 2011 Jul;12(4):250-6. doi: 10.3109/17482968.2011.560946. Epub 2011 Mar 4. PMID: 21375368.
- Schweitzer AD, Liu T, Gupta A, Zheng K, Seedial S, Shtilbans A, Shahbazi M, Lange D, Wang Y, Tsiouris AJ. Quantitative susceptibility mapping of the motor cortex in amyotrophic lateral sclerosis and primary lateral sclerosis. AJR Am J Roentgenol. 2015 May;204(5):1086-92. doi: 10.2214/AJR.14.13459. PMID: 25905946; PMCID: PMC4889122.
- Wainger BJ, Macklin EA, Vucic S, McIlduff CE, Paganoni S, Maragakis NJ, Bedlack R, Goyal NA, Rutkove SB, Lange DJ, Rivner MH, Goutman SA, Ladha SS, Mauricio EA, Baloh RH, Simmons Z, Pothier L, Kassis SB, La T, Hall M, Evora A, Klements D, Hurtado A, Pereira JD, Koh J, Celnik PA, Chaudhry V, Gable K, Juel VC, Phielipp N, Marei A, Rosenquist P, Meehan S, Oskarsson B, Lewis RA, Kaur D, Kiskinis E, Woolf CJ, Eggan K, Weiss MD, Berry JD, David WS, Davila-Perez P, Camprodon JA, Pascual-Leone A, Kiernan MC, Shefner JM, Atassi N, Cudkowicz ME. Effect of Ezogabine on Cortical and Spinal Motor Neuron Excitability in Amyotrophic Lateral Sclerosis: A Randomized Clinical Trial. JAMA Neurol. 2021 Feb 1.
