Amyotrophic Lateral Sclerosis (ALS)

Disease/Disorder

Definition

Amyotrophic lateral sclerosis (ALS), also known as “Lou Gehrig’s disease”, is a rapidly progressive neurodegenerative disease affecting voluntary motor control. ALS is characterized by a combination of both upper and lower motor neuron degeneration and exists on a spectrum of motor neuron disease. Presentations with purely upper motor neuron symptoms are classified as primary lateral sclerosis (PLS), while those with purely lower motor neuron symptoms are classified as progressive muscular atrophy (PMA).

Etiology

Most (90-95%) of ALS cases are classified as “sporadic ALS” (sALS) with no prior family history of disease. Up to 10% of ALS cases are classified as “familial ALS” (fALS) with positive family history in at least one other family member. There are roughly 50 identified genetic mutations associated with ALS, the majority of which are inherited in an autosomal dominant pattern. The most common (30-40%) cause of fALS is a hexanucleotide (GGGGCC) repeat expansion in the non-coding region of chromosome 9 open reading frame 72 (C9ORF72). The second most common (15-20%) cause of fALS are mutations in the superoxide dismutase 1 (SOD1) gene. Other less common genetic causes of fALS include mutations in the Fused in Sarcoma (FUS) gene and transactivation response DNA-binding protein (TARDBP) gene.¹

Epidemiology including risk factors and primary prevention

The global incidence of ALS is estimated as 1 to 2 cases per 100,000 individuals, with a lifetime risk of sALS ranging from approximately 1 in 600 to 1 in 2,000. The incidence increases with advancing age, peaking between 60 and 79 years. As the global population ages and improvements in ALS management continue to extend survival, the prevalence of the disease is anticipated to rise. ALS demonstrates a male predominance, with a standardized male-to-female incidence ratio of 1.34.^2,3

Both genetic susceptibility and environmental exposures are implicated in ALS pathogenesis. fALS accounts for 10–15% of cases, with the remaining majority classified as sporadic. Evidence of increased heritability, particularly observed in mother-daughter pairs, underscores the genetic contribution. The C9orf72 hexanucleotide repeat expansion, the most common genetic mutation associated with ALS, is linked to earlier disease onset, particularly among males.

A variety of environmental and occupational exposures have been associated with increased ALS risk. Potential contributing factors include industrial airborne chemicals such as nitric acid, styrene, chromium, nickel, and dichloromethane (methylene chloride), as well as exposure to pesticides, solvents, lead, and magnetic fields. Additional risk factors include a history of head trauma, military service, stroke, hypertension, and higher levels of physical activity. These associations suggest a multifactorial etiology involving both genetic predisposition and environmental triggers.⁴

Conversely, several factors have been associated with a decreased risk of ALS. These include the use of antidiabetic medications, higher body mass index (BMI), urban residence, diabetes mellitus, and chronic kidney disease. Further research is warranted to elucidate the biological mechanisms underlying these protective associations and to inform potential preventive strategies.^2,5

Patho-anatomy/physiology

The pathophysiology of ALS is not fully understood; however, it is presumed to result from a complex interaction between genetic and environmental factors. The primary pathology is motor neuron death in the motor cortex and spinal cord. Degeneration of corticospinal axons leads to spinal cord sclerosis, and motor neuron death in the brainstem and spinal cord causes muscle atrophy, especially in the tongue, throat, and limbs though eye and bladder control is usually preserved until late stages. Neuroinflammation accompanies neuron loss, via activation of glial cells. Both familial and sporadic ALS show abnormal protein aggregation, especially of TDP-43, which is mislocalized and phosphorylated. A working theory of ALS genes is that they present in three distinct categories: protein homeostasis, RNA homeostasis, and cytoskeletal dynamics.

Specific secondary or associated conditions and complications

A variety of secondary conditions can arise because of ALS, contributing significantly to patient morbidity and mortality. Among these, restrictive lung disease (RLD) is arguably the most critical, as advanced RLD and subsequent respiratory failure account for the majority of deaths in individuals with ALS. Other common complications include dysphagia, dysarthria, sialorrhea, progressive muscle weakness, and malnutrition. Psychological and cognitive challenges are also prevalent, with many patients experiencing depression or adjustment disorders. Cognitive impairment is recognized in a significant subset of individuals with ALS, and frontotemporal dementia, particularly associated with TDP-43 mutations, is now considered part of the same disease spectrum. Additional neuromuscular symptoms such as spasticity, muscle cramping, and fatigue are frequently reported. Furthermore, neurogenic bowel and bladder dysfunction are common, with many patients experiencing increased urinary frequency and other symptoms following their ALS diagnosis.^2,7,8

Essentials of Assessment

History

ALS often begins with focal weakness, typically in the limb or with bulbar symptoms like dysarthria or dysphagia. It progresses to adjacent regions with signs of both upper and lower motor neuron involvement, such as muscle weakness, cramps, fasciculations, spasticity, or atrophy. Cognitive or behavioral changes, including apathy and executive dysfunction, occur early in up to 50% of patients. Autonomic symptoms may appear, but sensory and visual symptoms are usually absent.

Physical examination

Physical examination should include thorough assessment of the four body regions (cranial, cervical, thoracic, lumbosacral) for the presence of upper and lower motor dysfunction. The following table illustrates exam findings that can be seen in ALS patients.

Figure 1. Upper and Lower motor neuron signs by body region⁹

Functional assessment

Functional assessment is variable depending on the location of first involvement and the rate/location of progression, but should be comprehensive to include mobility, activities of daily living, speech and swallowing, respiratory status, cognition and behavior, and affective state.

Imaging

• Cervical spine magnetic resonance imaging (MRI) is recommended to rule out myelopathy; however, it is rarely utilized for diagnostic purposes, despite usual anterior horn involvement.
• Brain MRI is recommended to evaluate for abnormalities in the motor tracts and to rule out multiple sclerosis. ALS-associated findings include atrophy of precentral gyri, temporal cortex, parietal cortex, frontal lobe, with poor survival correlated to volume loss in basal ganglia and limbic structures.
• Quantitative FLAIR analysis can reveal abnormalities in the corticospinal tract and corpus callosum.
• Advanced MRI techniques like diffusion tensor imaging (DTI) and multimodal approaches show promise for identifying biomarkers, including iron-related changes and network connectivity disruptions. These methods can detect structural changes even in presymptomatic individuals with C9orf72 mutations.
• Although not specific to ALS, PET imaging using metabolic and glial tracers offers insight into disease mechanisms and may serve as pharmacodynamic tools in clinical trials.¹¹

Supplemental assessment tools

In addition to history and physical examination, other assessments aid in the diagnosis of ALS. These include laboratory tests, electrodiagnostic testing, pulmonary function testing, as well as imaging mentioned above.

Electrodiagnostic studies are an extension of the history and physical examination and should be performed on all patients suspected to have ALS. As well as assisting in diagnosis, electrodiagnostic studies provide information about chronicity and extent of disease. Nerve conduction studies should be used to evaluate for peripheral neuropathy mimicking ALS and should include both motor and sensory studies of the upper and lower extremities with at least one side to side comparison. F waves minimum latencies can be prolonged in ALS but are nonspecific findings. Similarly, repetitive stimulation studies have been shown to have decrement in ALS with one study reporting CMAP amplitude decrease of at least 10% in the median nerve of 34% of patients examined. Needle electromyography should be performed to evaluate for a combination of acute (fibrillations, positive sharp waves) and chronic (long duration, large amplitude motor unit potentials) neurogenic abnormalities and should include examination of sufficient body regions to meet diagnostic criteria as described below. In addition, there must be evidence of progression over time and absence of electromyographic or neuroimaging evidence of another disease process that might explain the observed clinical signs.¹²

Figure 2. Revised El-Escorial Criteria. UMN- upper motor neuron, LMN- lower motor neuron, body regions- cranial, cervical, thoracic, lumbosacral

The Awaji-Shima criteria is similar to the El Escorial criteria except that it assigns equal importance to fasciculation potentials such as fibrillations and positive sharp waves. These criteria have been described as too restrictive for inclusion in clinical trials, so the Gold Coast criteria was developed to address this issue.

Figure 3. Gold Coast Criteria

The Gold coast criteria has been found to have higher sensitivity for ALS diagnosis than the El Escorial and Awaji-Shima criterion.¹³

At the initial evaluation of a patient with suspected ALS, pulmonary function testing (PFT) should be conducted to assess signs of restrictive lung disease. Key measurements include forced vital capacity (FVC), maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), and peak cough flow, all of which help determine respiratory muscle strength. If PFT results are borderline, nocturnal pulse oximetry studies may be useful to screen for nocturnal hypoventilation, a common early sign of respiratory compromise in ALS. Alongside respiratory assessment, laboratory testing is essential to rule out ALS mimics. Testing for anti-GM1 antibodies can help identify multifocal motor neuropathy, while creatine kinase (CK) levels may suggest primary muscle disease, though mild to moderate elevations can also occur in ALS. Additional evaluations should include vitamin B12 and copper levels to rule out nutritional causes of myelopathy, as well as antibody testing for myasthenia gravis-including acetylcholine receptor, MUSK, and LRP4 antibodies-to investigate possible neuromuscular junction disorders. Infectious causes of motor neuron disease, such as HTLV-1 and HIV, should also be considered and ruled out with appropriate serologic or viral load testing.

Early predictions of outcomes

Probability of death within 12 months is increased with the following characteristics:

• Age at diagnosis- Patients above the age of 75 at diagnosis have shown a 6 times higher mortality within 12 months than patients 65 years and younger at diagnosis.
• Body mass index (BMI) decrease– Patients having a BMI decrease of >=2 units within the past 6 months preceding diagnosis have been shown to have increased mortality within 12 months.
• Advanced functional impairment– Patients with an ALS function rating scale (ALS-FRS) <32 at diagnosis have been shown to have increased mortality within 12 months.

Respiratory variables such as FVC (<75%) are associated with poor prognosis over the course of disease but have not been shown to be a predictor of one year mortality from time of diagnosis.¹⁴

Environmental

Evaluation of a patient’s environmental surroundings should be a key component of the initial history. Elements such as availability of caregiver support, household accessibility, and job requirements should all be elicited. The role of social workers in a multidisciplinary clinic is invaluable to help find solutions for any of these factors that may lead to increased caregiver burden and applying for disability services. Home evaluation by physical and occupational therapists is useful prior to obtaining durable medical equipment (DME) such as power wheelchairs, Hoyer lift devices, grab bars, shower chairs, bedside commodes.

Social role and social support system

Keeping individuals engaged in their work and familial roles for as long as possible is important. A balance must be achieved between implementing energy-conserving interventions that help maintain these roles for the near future, while also planning the inevitable loss of function over time. Caregiver support should focus on assisting informal caregivers in considering and arranging nursing care, home health aides, or companions. This support can help decompress caregivers from the demands of basic personal care tasks, allowing them to focus more on broader household management responsibilities.

Facilitating difficult conversations in ALS care

Effective communication is critical in the management of ALS particularly when addressing sensitive topics such as diagnosis disclosure, life-sustaining interventions, and end-of-life care planning. To ease patients and families into these discussions, clinicians should prioritize building a trusting relationship through compassionate, honest, and patient-centered dialogue.

Disclosure of the ALS diagnosis should occur as soon as diagnostic certainty is established, allowing patients and their families adequate time to process the information and begin planning. Early discussions should also address the potential need for life-sustaining interventions, such as noninvasive ventilation, enteral feeding, and emergency life support measures, emphasizing that these options can improve quality of life and extend survival. Conversations about end-of-life issues-including tracheostomy, do-not-resuscitate (DNR) orders, and advance directives-should be approached proactively and revisited periodically, ensuring that patients’ evolving wishes are respected. Introducing these topics gradually, offering clear explanations without overwhelming the patient, and involving a multidisciplinary team (including palliative care, social work, and mental health support) can help create a supportive environment where patients feel empowered to make informed decisions aligned with their values and goals.

Rehabilitation Management and Treatments

Available or current treatment guidelines

Treatment guidelines for ALS aim to provide a comprehensive, multidisciplinary approach to managing this progressive neurodegenerative disease. While no cure currently exists, evidence-based strategies focus on slowing disease progression, relieving symptoms, and maintaining quality of life for as long as possible.

Patients with ALS have heterogeneous symptoms severity independent of chronicity therefore all secondary conditions should be assessed at each patient’s appointment. Referral should be made to a multidisciplinary ALS center for treatment as this has shown to prolong survival and improve patient quality of life with earlier patient use of noninvasive ventilation and enteral feeding.¹⁵

Medications

Medications are approved by the United States Food and Drug Administration for the treatment of ALS.

• Riluzole (Rilutek) may slow disease progression and should be offered to all patients with ALS. In patients with an FVC>60% and disease duration <5 years, riluzole has been shown to prolong tracheostomy free survival by an average of 2-3 months however some studies suggest a larger benefit. Fatigue and nausea are common side effects; liver function testing must be performed regularly to monitor elevations in liver enzymes.
• Radicava (Edaravone) has been reported to provide functional improvement in a subset of patients with ALS and should be offered to all patients who meet those criteria. A slowing of decline in reported ALS-FRS scores was seen in patients with FVC>80%, disease duration <2 years, and initial ALS-FRS with score >=2 in each category. This medication is administered as an infusion over 14 days a month; patients who elect this treatment should be referred to interventional radiology for port placement.
• Patients can take both Riluzole and Radicava simultaneously.^15,16

Restrictive Lung Disease

• Regular respiratory monitoring is essential; assessments include FVC, overnight oximetry, and blood gas measurements (e.g., pCO₂, bicarbonate).
• Noninvasive ventilation (NIV), such as BiPAP, improves both survival and quality of life. It should be considered when respiratory symptoms appear or when testing shows FVC decline, elevated pCO₂, or nocturnal desaturation. Indications for initiating NIV include FVC <50%, symptoms of hypoventilation, abnormal nocturnal oximetry, or elevated serum bicarbonate.
• Regular screening with overnight oximetry or other methods like maximum inspiratory pressure (MIP) and CO₂ monitoring is recommended to detect early respiratory compromise.
• Mechanical insufflation/exsufflation (cough assist devices) should be used to aid airway clearance and reduce risk of atelectasis, especially when peak cough flow is <270 L/min.
• Gastrostomy placement is ideally performed before severe respiratory compromise (e.g., before need for >16 hours/day of NIV), as poor respiratory status increases procedural risk.
• Invasive ventilation (tracheostomy) may be offered in advanced stages based on patient preference, understanding the significant care burden and impact on quality of life.²

Dysphagia/Weight Loss

Weight loss in ALS is multifactorial with etiologies including progressive dysphagia, significant respiratory burden, hypermetabolism, depression, functional inability to eat, and gastroparesis causing early satiety.

• Weight loss >10% of baseline weight is a criterion for recommending a PEG tube in ALS.
• There is an increasing body of evidence that long-term percutaneous endoscopic gastrotomy (PEG) placement leads to increased survival in ALS patients.
• Discussion of PEG placement should be done early in the disease process and placement should ideally occur when the FVC>50%. More than half of patients with ALS undergo PEG tube placement.
• Esophageal scintigraphy was able to detect dysphagia in almost 70% of ALS patients who had no swallowing symptoms; it may be a useful screening tool for dysphagia in ALS.⁹

Dysarthria

Patients with ALS may exhibit spastic, flaccid, or mixed dysarthria, each contributing to progressive declines in speech intelligibility. Regular assessment by a licensed speech-language pathologist is essential to systematically monitor speech function and implement interventions as needed. Comprehensive dysarthria evaluations should address not only the severity of articulatory impairment but also the functional limitations in verbal communication. Given the progressive nature of ALS, early introduction of augmentative and alternative communication (AAC) strategies is critical. These may include partner-assisted communication techniques, written or typed communication methods, picture or word boards, and advanced eye-gaze communication systems to support ongoing interaction and maintain quality of life.⁹

Sialorrhea

The treatment of sialorrhea in ALS should be guided by how much the symptom impacts the patient’s comfort and quality of life. Medication options commonly include glycopyrrolate, which helps reduce saliva production. Caution should be exercised when considering tricyclic antidepressants for sialorrhea, as these medications can cause significant side effects such as sedation, cognitive impairment, and cardiovascular complications, particularly in individuals with ALS who may already be vulnerable. For symptoms that are refractory to medical therapy, botulinum toxin injections into the salivary glands may be an effective alternative to reduce saliva production by decreasing acetylcholine in the presynaptic nerve terminals of the salivary gland.

Spasticity

Spasticity in patients with ALS can be painful and significantly impair functional mobility, contributing to reduced quality of life. Pharmacologic management options for spasticity include baclofen, tizanidine, dantrolene, benzodiazepines, and gabapentin. Careful monitoring for adverse effects is critical, as these agents can exacerbate sedation, muscle weakness, and other systemic complications, which may further impact functional status. In cases of moderate to severe spasticity, botulinum toxin injections may be considered as a treatment option and have demonstrated a favorable safety profile; however, the decision to pursue this intervention should be individualized, given the potential risk of worsening muscle weakness. For individuals with severe, painful spasticity refractory to standard therapies, intrathecal baclofen pump therapy has been shown to provide significant clinical benefit.^2,10,19

Pseudobulbar Affect

Dextromethorphan-quinidine (Nuedexta) has been shown to improve pseudobulbar affect (PBA) symptoms in ALS. This medication also seemed to have subjectively measured beneficial effects on overall bulbar function with improved speech, improved dysphagia, decreased secretions reported on ALS-FRS scale.¹⁷

Impaired Mobility and Activities of Daily Living

In ALS, a patient’s mobility and ability to perform activities of daily living (ADLs) should be regularly assessed during each appointment to ensure appropriate care and support. Physical and occupational therapists in a multidisciplinary clinic play a key role in evaluating and addressing these needs. Fall prevention is a crucial aspect of managing ALS, as patients are at increased risk due to muscle weakness and coordination issues. For those with ankle dorsiflexion weakness, prescribing ankle-foot orthoses (AFOs) can help prevent falls. Ground reaction force AFOs are typically preferred as they also provide support to compensate for eventual quadriceps weakness. Rollator walkers are often useful as they not only offer mobility support but also provide a seat for rest when needed. Early discussion about custom power wheelchair seating should be part of the care plan, particularly if patients experience recurrent falls despite proper orthotic use.

Hand weakness can significantly impact a patient’s ability to carry out essential ADLs, such as dressing, eating, and maintaining personal hygiene. To assist with these challenges, wrist-hand orthoses, built-up utensils, and dressing aids can be trialed to help patients maintain as much independence as possible. These adaptive tools are essential in promoting autonomy and enhancing quality of life for ALS patients as their disease progresses.

Muscle Pain/Cramping

Muscle pain and cramping are common and often debilitating symptoms in ALS patients, significantly impacting their quality of life. As motor neurons degenerate, muscle weakness and stiffness can lead to increased discomfort, cramping, and spasticity. Management of these symptoms requires careful consideration of both efficacy and safety, given the complex nature of ALS and the risk of side effects from various treatments.

Narcotic medications, while potentially effective for pain relief, should be used with caution in ALS patients due to their respiratory depressant effects, which can exacerbate respiratory complications associated with the disease. For cramping-related pain, Mexiletine, a sodium channel blocker, has shown benefits in some patients with ALS. However, it is important to monitor the patient’s cardiac health with an EKG before prescribing Mexiletine, as it can prolong the QT interval and increase the risk of arrhythmias. Anecdotal evidence suggests that over-the-counter magnesium supplementation and tonic water, which contains quinine, may also provide some relief for muscle cramps. Additionally, medications such as muscle relaxers and neuropathic pain agents can be trialed on an individual basis to address spasticity or nerve-related pain, but each treatment should be carefully tailored to the patient’s specific symptoms and needs.

Neurogenic Bowel/Bladder

Urinary incontinence in ALS is typically functional, meaning it results from physical limitations or difficulty accessing the bathroom in time, though it may also be linked to frontal lobe dysfunction affecting bladder control. This issue can significantly impact quality of life, particularly as mobility declines. Management strategies include timed voiding to establish routine bladder emptying and intermittent catheterization to reduce residual urine and prevent urinary tract infections. If self-catheterization becomes too difficult or the process of toileting becomes overly burdensome, an indwelling urinary catheter may be considered. For male patients, condom catheters used at night can help avoid nighttime awakenings and reduce the risk of falls or fatigue from frequent bathroom trips.

Constipation is a frequent and often distressing issue among ALS patients, largely due to immobility, reduced fluid intake, and weakened abdominal muscles. Neurogenic bowel dysfunction may also result from changes in autonomic nervous system control. A proactive approach to bowel care is essential. Increased dietary fiber, adequate hydration, and tailored nutrition plans, ideally managed with the help of a clinic nutritionist, are foundational steps. Many patients require pharmacologic support, such as stool softeners, osmotic agents, or suppositories, to maintain regular bowel movements. Establishing a consistent bowel regimen can greatly enhance comfort and reduce complications like impaction or bowel incontinence.⁸

Cognition

In a study of 146 ALS patients, 30% experienced cognitive decline within six months, even if they were initially cognitively intact and these individuals had faster disease progression and shorter survival. It is important to evaluate other potential causes of cognitive decline, including infection, electrolyte abnormalities, stroke, vascular issues, Alzheimer’s disease, and medication effects. Although cognitive and behavioral assessments are not part of the formal ALS diagnostic criteria, they are essential for informing prognosis, guiding care decisions, and understanding the impact on both patients and their families. Evaluations should include multiple cognitive domains and behavioral changes, using standardized tools such as the Mini Mental Status Exam (MMSE) or the Montreal Cognitive Assessment (MoCA). Based on the degree of impairment, adjustments to the living environment and caregiver support may also be necessary.

Depression/Adjustment Disorder

Depression is a common comorbidity in ALS, with recent estimates suggesting a prevalence of around 34%, in most cases being classified as mild to moderate. The emotional burden of facing a progressive, incurable illness combined with the gradual loss of independence places patients at significant risk for mood disturbances. While depression may not always meet the criteria for major depressive disorder, symptoms such as sadness, apathy, hopelessness, and anxiety can significantly impact quality of life, adherence to treatment, and even survival. Early recognition and intervention are essential. Treatment options include pharmacologic therapy, such as selective serotonin reuptake inhibitors (SSRIs) or tricyclic antidepressants (TCAs), which may also help with associated symptoms like sleep disruption or chronic pain. Referral to a psychiatry specialist can provide additional support through counseling, medication management, and coordination of mental health care. A multidisciplinary approach that includes psychological support is key to comprehensive ALS management.¹⁷

Fatigue

Fatigue is a common and often debilitating symptom in ALS, and it is typically multifactorial in origin. Contributing factors may include hypercarbia from restrictive lung disease, depression, inadequate caloric intake, progressive muscle weakness, disrupted sleep hygiene, anemia, and hypothyroidism. Given this wide range of potential causes, a thorough evaluation is essential before initiating treatment to ensure that underlying, reversible contributors are appropriately managed.

For patients with significant restrictive lung disease, increasing pressure support on noninvasive ventilation can help reduce fatigue by improving nighttime ventilation and decreasing carbon dioxide retention. In select cases where fatigue persists despite addressing underlying factors, pharmacologic interventions may be considered. Modafinil, a wakefulness-promoting agent, has shown some benefit in alleviating fatigue in ALS and may be a helpful adjunct in carefully selected patients.¹⁸

Cutting Edge/Emerging and Unique Concepts and Practice

Emerging/unique interventions

Some innovative approaches for ALS treatment have shown promise and challenges in recent clinical trials. Tofersen, an antisense oligonucleotide targeting the SOD1 gene, demonstrated a decrease in SOD1 concentrations in cerebrospinal fluid in early-phase trials, suggesting potential therapeutic benefits. However, a Phase 3 trial failed to meet its primary endpoint of reducing the 6-month rate of ALS-FRS decline compared to placebo. Despite this, data from the open-label extension study indicated that earlier initiation of tofersen may slow disease progression in faster-progressing patients and stabilize clinical outcomes in slower-progressing individuals. This suggests that timing of treatment may be critical for maximizing efficacy, and further studies are needed to explore its full potential.

Another promising therapy, AMX0035, combines sodium phenylbutyrate and tauroursodeoxycholic acid (TUDCA) and has shown positive effects on disease progression, as evidenced by improved ALS-FRS scores, along with a modest survival benefit. This combination is undergoing further study in a larger cohort to better establish its efficacy. While AMX0035 is not yet FDA-approved in the United States, it has received approval in both the European Union and Canada. However, it is important for patients to be educated about the distinction between AMX0035 and TUDCA, as the latter alone has not been fully studied for ALS treatment. In contrast, the NEUROWN stem cell therapy trial did not show any benefit over placebo, highlighting the complexity and difficulty of finding effective stem cell-based treatments for ALS.²

Gaps in the Evidence-Based Knowledge

The lack of a clear pathophysiological understanding of ALS makes developing effective treatments particularly challenging. Although much has been learned about the disease progression, including the degeneration of motor neurons and the involvement of various cellular and molecular pathways, the exact mechanisms remain unclear. This uncertainty hinders the identification of targeted therapies and complicates the development of drugs that could slow or halt disease progression. Additionally, the variability of ALS symptoms across patients further complicates treatment strategies, as different individuals may respond differently to various therapies. Without a deeper understanding of the underlying disease processes, progress in finding effective treatments is limited.

References

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16. Miller RG, Jackson CE, Kasarskis EJ, et al. Practice Parameter update: The care of the patient with amyotrophic lateral sclerosis: Multidisciplinary care, symptom management, and cognitive/behavioral impairment (An evidence-based review): Report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology. 2009;73(15):1227-1233
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Original Version of the Topic

Anthony Chiodo, MD. Amyotrophic Lateral Sclerosis. 12/27/2012.

Previous Revision(s) of the Topic

Jennifer Yang, MD, Nicholas Georgelos DO. Amyotrophic Lateral Sclerosis. 3/27/2017.

Shailesh Reddy, MD, Hannah Machemehl, MD, Yessar Hussain, MD. Amyotrophic Lateral Sclerosis (ALS). 4/20/2022.

Author Disclosure

Erika Trovato, DO
Nothing to Disclose

Jennifer Hegedus, DO
Nothing to Disclose

Issac Ichoa, DO
Nothing to Disclose

Kenny Tse, DO
Nothing to Disclose