2024 ICD-10-CM Diagnosis Code G71.19

Other specified myotonic disorders

ICD-10-CM Code:
Short Description:
Other specified myotonic disorders
Is Billable?
Yes - Valid for Submission
Chronic Condition Indicator: [1]
Not chronic
Code Navigator:

Code Classification

  • Diseases of the nervous system
    • Diseases of myoneural junction and muscle
      • Primary disorders of muscles

G71.19 is a billable diagnosis code used to specify a medical diagnosis of other specified myotonic disorders. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2023 through September 30, 2024.

Approximate Synonyms

The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

  • Autosomal recessive axonal neuropathy with neuromyotonia
  • Axonal neuropathy
  • Cataract in systemic disorders
  • Eye closing finding
  • Eye closure myotonia
  • Infantile myotonia
  • Isaacs syndrome
  • Movement of eyelid - finding
  • Myotonia
  • Myotonia
  • Myotonia
  • Myotonia fluctuans
  • Myotonia permanens
  • Myotonic cataract
  • Myotonic disorder
  • Myotonic warm-up phenomenon
  • Myotonic warm-up phenomenon - hand grip
  • Neuromyotonia
  • Neuromyotonia
  • Non dystrophic myotonia
  • Paramyotonia congenita
  • Peripheral axonal neuropathy
  • Potassium aggravated myotonia
  • Potassium aggravated myotonia
  • Pseudomyotonia
  • Rippling muscle disease
  • Rippling muscle disease
  • Rippling muscle disease with myasthenia gravis

Clinical Classification

Clinical Category:
CCSR Category Code:
Inpatient Default CCSR:
Y - Yes, default inpatient assignment for principal diagnosis or first-listed diagnosis.
Outpatient Default CCSR:
Y - Yes, default outpatient assignment for principal diagnosis or first-listed diagnosis.

Clinical Information

  • Myotonia - prolonged failure of muscle relaxation after contraction. this may occur after voluntary contractions, muscle percussion, or electrical stimulation of the muscle. myotonia is a characteristic feature of myotonic disorders.
  • Myotonia Congenita - inherited myotonic disorders with early childhood onset myotonia. muscular hypertrophy is common and myotonia may impair ambulation and other movements. it is classified as thomsen (autosomal dominant) or becker (autosomal recessive) generalized myotonia mainly based on the inheritance pattern. becker type is also clinically more severe. an autosomal dominant variant with milder symptoms and later onset is known as myotonia levior. mutations in the voltage-dependent skeletal muscle chloride channel are associated with the disorders.
  • Myotonic Disorders - diseases characterized by myotonia, which may be inherited or acquired. myotonia may be restricted to certain muscles (e.g., intrinsic hand muscles) or occur as a generalized condition.
  • Myotonic Dystrophy - neuromuscular disorder characterized by progressive muscular atrophy; myotonia, and various multisystem atrophies. mild intellectual disability may also occur. abnormal trinucleotide repeat expansion in the 3' untranslated regions of dmpk protein gene is associated with myotonic dystrophy 1. dna repeat expansion of zinc finger protein-9 gene intron is associated with myotonic dystrophy 2.
  • Osteochondrodysplasias - abnormal development of cartilage and bone.
  • Isaacs Syndrome - a rare neuromuscular disorder with onset usually in late childhood or early adulthood, characterized by intermittent or continuous widespread involuntary muscle contractions; fasciculation; hyporeflexia; muscle cramp; muscle weakness; hyperhidrosis; tachycardia; and myokymia. involvement of pharyngeal or laryngeal muscles may interfere with speech and breathing. the continuous motor activity persists during sleep and general anesthesia (distinguishing this condition from stiff-person syndrome). familial and acquired (primarily autoimmune) forms have been reported. (from ann ny acad sci 1998 may 13;841:482-496; adams et al., principles of neurology, 6th ed, p1491)
  • Myotonic Disorder - an inherited or acquired, localized or generalized disorder affecting the muscles. it may be associated with abnormalities in the chloride or sodium channels of the muscles. it is characterized by delayed muscle relaxation following stimulation or contraction. representative examples include myotonia congenita and myotonic dystrophy.
  • Acute Motor and Sensory Axonal Neuropathy|Acute Motor And Sensory Axonal Neuropathy|Acute Motor-Sensory Axonal Neuropathy|Acute Motor-Sensory Axonal Neuropathy - a subtype of guillain-barre syndrome that targets sensory motor axons, and is characterized by acute onset of quadriparesis, distal sensory loss, areflexia, and respiratory insufficiency.
  • Acute Motor Axonal Neuropathy|AMAN - a subtype of guillain-barre syndrome that targets motor axons, and is characterized by symmetric limb weakness, diffuse areflexia, facial and oropharyngeal muscle weakness, and respiratory insufficiency.
  • Axonal Neuropathy - any nerve disorder affecting the axon of a nerve.
  • GAN wt Allele|GAN1|Giant Axonal Neuropathy (Gigaxonin) Gene|Gigaxonin wt Allele|KLHL16 - human gan wild-type allele is located in the vicinity of 16q24.1 and is approximately 65 kb in length. this allele, which encodes gigaxonin protein, is involved in both ubiquitination and neurofilament structure. mutation of the gene is associated with giant axonal neuropathy.
  • Giant Axonal Neuropathy - a rare inherited disorder affecting the neurofilaments. it is caused by mutations in the gan gene. it is characterized by the presence of abnormally large nerve cell axons. signs and symptoms include difficulty walking, sensory disturbances, lack of motor coordination and abnormal reflexes in the limbs.
  • Spinocerebellar Ataxia, Autosomal Recessive, with Axonal Neuropathy 2|AOA2|Ataxia with Oculomotor Apraxia Type 2|SCAN2 - an autosomal recessive condition caused by mutation(s) in the setx gene, encoding probable helicase senataxin. it is characterized by juvenile onset progressive cerebellar ataxia, axonal sensorimotor peripheral neuropathy, and increased concentrations of serum alpha-fetoprotein. oculomotor apraxia is common, but is not always present.
  • Myotonic Cataract - a cataract occurring as a sequela of myotonic dystrophy.

Tabular List of Diseases and Injuries

The following annotation back-references are applicable to this diagnosis code. The Tabular List of Diseases and Injuries is a list of ICD-10-CM codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more.

Inclusion Terms

Inclusion Terms
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
  • Myotonia fluctuans
  • Myotonia permanens
  • Neuromyotonia Isaacs
  • Paramyotonia congenita (of von Eulenburg)
  • Pseudomyotonia
  • Symptomatic myotonia

Index to Diseases and Injuries References

The following annotation back-references for this diagnosis code are found in the injuries and diseases index. The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10-CM code(s).

Convert G71.19 to ICD-9-CM

  • ICD-9-CM Code: 359.29 - Myotonic disorder NEC

Patient Education

Neuromuscular Disorders

Neuromuscular disorders affect your neuromuscular system. They can cause problems with:

  • The nerves that control your muscles
  • Your muscles
  • Communication between your nerves and muscles

These disorders can cause your muscles to become weak and waste away. You may also have symptoms such as spasms, twitching, and pain.

Examples of neuromuscular disorders include:

  • Amyotrophic lateral sclerosis
  • Muscular dystrophy
  • Myasthenia gravis
  • Spinal muscular atrophy

There can be different causes for these diseases. Many of them are genetic.This means they are inherited (run in families) or are caused by a new mutation in your genes. Some neuromuscular disorders are autoimmune diseases. Sometimes the cause is unknown.

Many neuromuscular diseases have no cure. But treatments may improve symptoms, increase mobility, and lengthen life.

[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.


[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.