When viewing this topic in a different language, you may notice some differences in the way the content is structured, but it still reflects the latest evidence-based guidance.

Amyotrophic lateral sclerosis

Last reviewed: 10 Apr 2025
Last updated: 27 Sep 2024

Summary

Definition

History and exam

Key diagnostic factors

  • presence of risk factors
  • upper extremity weakness
  • stiffness, with poor co-ordination and balance
  • spastic, unsteady gait
  • painful muscle spasms
  • difficulties in arising from chairs and climbing stairs
  • foot drop
  • stiffness and decreased balance with impact on gait
  • head drop
  • progressive difficulties in maintaining erect posture, with stooping
  • muscle atrophy
  • increased lumbar lordosis and tendency for abdominal protuberance
  • hyper-reflexia
  • dyspnoea
  • coughing and choking on liquids (including secretions) and eventually on food
  • strained, slow speech
  • slurred, nasal, and, at times, dysphonic speech
  • hypophonic speech
Full details

Other diagnostic factors

  • propensity for falls
  • sialorrhoea and drooling
  • inappropriate bursts of crying or laughing
  • cognitive impairment
  • features of frontotemporal dementia
Full details

Risk factors

  • genetic predisposition or family history
  • age >40 years
  • military service
  • professional athletic activity
  • cigarette smoking
  • agricultural chemical exposure
  • lead exposure
Full details

Diagnostic investigations

1st investigations to order

  • clinical diagnosis
Full details

Investigations to consider

  • electromyography (EMG) and nerve conduction studies
  • repetitive nerve stimulation
  • MRI brain and spine
  • anti-GM1 antibodies
  • voltage-gated calcium-channel antibodies
  • acetylcholine receptor (AChR) and muscle-specific tyrosine kinase (MuSK) antibodies
  • vitamin B₁₂
  • creatine kinase
  • lumbar puncture
  • HIV test
  • genetic testing
Full details

Treatment algorithm

ONGOING

all patients

Contributors

Authors

Christen Shoesmith, MD, FRCPC

Associate Professor of Neurology

Clinical Neurological Sciences

London Health Sciences Centre

London

Ontario

Canada

Disclosures

CS has received honoraria from Mitsubishi Tanabe Pharma Canada for participating in scientific medical advisory boards and for presenting at ALS CME events. She has also received stipends for consultancy work for Biogen. She is the chair of the CALS (Canadian ALS Research Network) and in that capacity sits on the scientific medical advisory board for ALS Canada. She is the site PI for several multi-centre clinical trials, including trials sponsored by Mitsubishi Tanabe, AL-S Pharma, Sanofi, Calico, and Cytokintetics. CS is an author of references cited in this topic.

Acknowledgements

Dr Christen Shoesmith would like to gratefully acknowledge Professor Christopher J. McDermott, Dr Laura Simionescu, and Dr Jeremy Shefner, previous contributors to this topic.

Disclosures

CJM received fees for membership of data monitoring committees from Orion Pharma and Orphazyme. LS and JS declare that they have no competing interests.

Peer reviewers

William S. David, MD, PhD

Associate Professor of Neurology

Harvard Medical School

Boston

MA

Disclosures

WSD declares that he has no competing interests.

Leo McCluskey, MD MBE

Associate Professor of Neurology

University of Pennsylvania

Philadelphia

PA

Disclosures

LM declares that he has no competing interests.

Martin R. Turner, MA, MBBS, PhD, MRCP

MRC/MNDA Lady Edith Wolfson Clinician Scientist & Honorary Consultant Neurologist

Oxford University Department of Clinical Neurology

John Radcliffe Hospital

Oxford

UK

Disclosures

MRT is a co-author of "Motor Neuron Disease – A Practical Manual" (Oxford University Press, 2010), which is a summary of his own understanding and practice, and which strongly influenced the recommendations for revision of the current article. He receives a proportion of royalties derived from sales of this book.

References

Our in-house evidence and editorial teams collaborate with international expert contributors and peer reviewers to ensure that we provide access to the most clinically relevant information possible.

Key articles

Shoesmith C, Abrahao A, Benstead T, et al. Canadian best practice recommendations for the management of amyotrophic lateral sclerosis. CMAJ. 2020 Nov 16;192(46):E1453-68.Full text  Abstract

Andersen PM, Abrahams S, Borasio GD, et al. EFNS guidelines on the clinical management of amyotrophic lateral sclerosis (MALS) - revised report of an EFNS task force. Eur J Neurol. 2012 Mar;19(3):360-75.Full text  Abstract

Brooks BR, Miller RG, Swash M, et al; World Federation of Neurology Research Group on Motor Neuron Diseases. El Escorial revisited: revised criteria for the diagnosis of amyotrophic lateral sclerosis. Amyotroph Lateral Scler Other Motor Neuron Disord. 2000 Dec;1(5):293-9. Abstract

de Carvalho M, Dengler R, Eisen A, et al. Electrodiagnostic criteria for diagnosis of ALS. Clin Neurophysiol. 2008 Mar;119(3):497-503. Abstract

Shefner JM, Al-Chalabi A, Baker MR, et al. A proposal for new diagnostic criteria for ALS. Clin Neurophysiol. 2020 Aug;131(8):1975-8.Full text  Abstract

Miller RG, Jackson CE, Kasarskis EJ, et al; Quality Standards Subcommittee of the American Academy of Neurology. Practice parameter update: the care of the patient with amyotrophic lateral sclerosis: multidisciplinary care, symptom management, and cognitive/behavioral impairment (an evidence-based review). Neurology. 2009 Oct 13;73(15):1227-33.Full text  Abstract

Miller RG, Jackson CE, Kasarskis EJ, et al; Quality Standards Subcommittee of the American Academy of Neurology. Practice parameter update: the care of the patient with amyotrophic lateral sclerosis: drug, nutritional, and respiratory therapies (an evidence-based review). Neurology. 2009 Oct 13;73(15):1218-26. [Errata in: Neurology. 2009 Dec 15;73(24):2134; Neurology. 2010 Mar 2;74(9):781.]Full text  Abstract

Reference articles

A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.
  • Differentials

    • Cervical spondylosis with myelopathy and radiculopathy
    • Multifocal motor neuropathy
    • Inclusion body myositis
    More Differentials
  • Guidelines

    • Evidence-based consensus guidelines for ALS genetic testing and counseling
    • Respiratory management of patients with neuromuscular weakness
    More Guidelines
  • padlock-lockedLog in or subscribe to access all of BMJ Best Practice

Use of this content is subject to our disclaimer