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PubMed This is a summary of 16 peer-reviewed journal articles Updated
Neurology · Charcot-Marie-Tooth disease

Can CMT Cause Breathing Problems and Hearing Loss?

At a Glance

While primarily affecting the limbs, Charcot-Marie-Tooth (CMT) disease can rarely cause breathing problems or hearing loss if the neuropathy affects the phrenic or auditory nerves. Symptoms like shortness of breath when lying flat, hoarseness, or difficulty understanding speech require prompt medical evaluation.

In this answer

3 sections

01

Breathing Problems and Respiratory Muscle Weakness

02

Hearing Loss and Auditory Neuropathy

03

When to Seek Medical Care

Yes, while Charcot-Marie-Tooth (CMT) disease is primarily known for causing weakness and numbness in the hands, arms, feet, and legs, it can rarely cause breathing problems or hearing loss. These symptoms occur when the neuropathy extends beyond the typical limbs and affects the nerves controlling your lungs or your ears [1][2]. While these complications are uncommon in the broader CMT community, specific genetic subtypes—such as CMT1E, CMT2C, CMT4, and CMTX1—are known to sometimes involve the phrenic nerve or the auditory nerves. Even if you have not had genetic testing to confirm your exact subtype, it is crucial to seek prompt medical evaluation if you experience changes in your breathing or hearing.

Breathing Problems and Respiratory Muscle Weakness

When CMT affects breathing, it is typically because the condition has involved the phrenic nerve. The phrenic nerve is responsible for sending electrical signals to your diaphragm, the primary muscle used for breathing [1][3]. If this nerve becomes damaged, the diaphragm weakens, leading to a condition called restrictive pulmonary dysfunction [1].

Certain subtypes of CMT, such as CMT2C and CMT4 variants (like CMT4B1), have also been strongly linked to vocal cord paralysis [4][5]. When the nerves controlling the vocal cords are affected, it can restrict the airway and make breathing difficult [6].

Signs of respiratory involvement to watch for include:

  • Shortness of breath, particularly when lying flat (orthopnea)
  • Frequent morning headaches or excessive daytime sleepiness (practical signs that your breathing is compromised at night)
  • A new or persistent hoarseness in your voice [7]
  • Stridor, which is a high-pitched wheezing sound when breathing in [6][5]

If you develop any of these symptoms, bring them to the attention of your neurologist, who can refer you to the appropriate specialists. A pulmonologist (lung specialist) may recommend pulmonary function tests (PFTs)—which simply involve blowing into a specialized tube—to check your lung capacity. You may also be referred for a sleep study (polysomnography) to check for nighttime breathing issues, or an ENT (Ear, Nose, and Throat specialist) to evaluate your vocal cords [7][5]. Depending on the results, therapies like non-invasive ventilation at night can be highly effective at supporting your breathing.

Hearing Loss and Auditory Neuropathy

Hearing loss in CMT is generally classified as sensorineural hearing loss (SNHL) or auditory neuropathy spectrum disorder (ANSD) [2][8]. Unlike conductive hearing loss, which involves a physical blockage in the ear, this type of hearing loss occurs when the auditory nerve—the nerve responsible for carrying sound signals from your inner ear to your brain—becomes damaged [9][10].

Certain subtypes, such as CMT4C, are closely associated with hearing loss, though auditory nerve involvement can occasionally be seen in other rare genetic mutations [11][12].

Key signs of auditory nerve involvement:

  • Difficulty understanding speech, especially in noisy environments like restaurants or social gatherings [13][14]
  • A feeling that you can “hear” someone talking, but the words sound muffled or unclear [9]
  • Gradual or progressive worsening of hearing over time

If you notice changes in your hearing, it is important to be evaluated by an audiologist. Because the inner ear structures (like the hair cells) often remain healthy while the nerve itself is impaired, specialized tests like an Auditory Brainstem Response (ABR) test are required to accurately diagnose auditory neuropathy [9]. For severe hearing loss in CMT, rehabilitation strategies such as hearing aids or cochlear implants can be effective. While cochlear implants bypass damaged inner ear structures to directly stimulate the auditory nerve, in patients with CMT they rely on stimulating whatever functional nerve fibers remain [8][15][16]. Because of this, your audiologist can help determine if this treatment is a good fit for your specific nerve damage.

When to Seek Medical Care

Because respiratory and hearing symptoms are rare, they may not immediately be recognized as related to your CMT. Do not dismiss shortness of breath, voice changes, or hearing difficulties as standard aging or general fatigue. Prompt medical evaluation can help identify the root cause of these symptoms and provide you with treatments that protect your long-term health and quality of life.

Common questions in this guide

Can Charcot-Marie-Tooth disease cause breathing problems?
Yes, in rare cases CMT can affect the phrenic nerve, which controls the diaphragm, or cause vocal cord paralysis. This can lead to shortness of breath, particularly when lying flat, or sleep-related breathing issues like morning headaches.
Does CMT cause hearing loss?
Yes, certain genetic subtypes of CMT can damage the auditory nerve, causing sensorineural hearing loss or auditory neuropathy. This often first presents as difficulty understanding speech, especially in noisy environments like restaurants.
What are the signs of respiratory issues in CMT?
Key signs include feeling out of breath when lying down, frequent morning headaches, excessive daytime sleepiness, persistent hoarseness, and stridor, which is a high-pitched wheezing sound when breathing in.
How is hearing loss from CMT treated?
Because CMT-related hearing loss affects the auditory nerve rather than the physical structures of the ear, it is often managed with specialized rehabilitation. Depending on the remaining functional nerve fibers, audiologists may recommend hearing aids or cochlear implants.
When should I see a doctor for rare CMT symptoms?
If you have CMT, you should see a specialist if you notice new hoarseness, high-pitched wheezing, shortness of breath when lying flat, or if you frequently need people to repeat themselves in noisy environments.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Given my specific genetic subtype of CMT, am I at an increased risk for phrenic or auditory nerve involvement?
  2. 2.Should I be scheduling baseline pulmonary function tests (PFTs) to monitor my respiratory muscle strength even before I experience breathing symptoms?
  3. 3.If I am experiencing shortness of breath when lying flat or frequent morning headaches, can you refer me for a sleep study or to a pulmonologist?
  4. 4.What type of hearing test should I request if I am struggling to understand speech in noisy environments?
  5. 5.Do I need to see an Ear, Nose, and Throat (ENT) specialist to evaluate my vocal cords if my voice has become persistently hoarse?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

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References

References (16)
  1. 1

    An MFN2-related Charcot-Marie-Tooth Disease Patient with Optic Nerve Atrophy, Neurogenic Bladder Dysfunction, and Diaphragmatic Weakness.

    Kimura Y, Nishikawa A, Hashiguchi A, et al.

    Internal medicine (Tokyo, Japan) 2022; (61(11)):1743-1747 doi:10.2169/internalmedicine.6487-20.

    PMID: 34803088
  2. 2

    Hearing loss in inherited peripheral neuropathies: Molecular diagnosis by NGS in a French series.

    Lerat J, Magdelaine C, Roux AF, et al.

    Molecular genetics & genomic medicine 2019; (7(9)):e839 doi:10.1002/mgg3.839.

    PMID: 31393079
  3. 3

    Charcot-Marie-Tooth Disease and Other Hereditary Neuropathies.

    Klein CJ

    Continuum (Minneapolis, Minn.) 2020; (26(5)):1224-1256 doi:10.1212/CON.0000000000000927.

    PMID: 33003000
  4. 4

    Screening for SH3TC2 gene mutations in a series of demyelinating recessive Charcot-Marie-Tooth disease (CMT4).

    Piscosquito G, Saveri P, Magri S, et al.

    Journal of the peripheral nervous system : JPNS 2016; (21(3)):142-9 doi:10.1111/jns.12175.

    PMID: 27231023
  5. 5

    Vocal cord paralysis in Charcot-Marie-Tooth type 4b1 disease associated with a novel mutation in the myotubularin-related protein 2 gene: A case report and review of the literature.

    Zambon AA, Natali Sora MG, Cantarella G, et al.

    Neuromuscular disorders : NMD 2017; (27(5)):487-491 doi:10.1016/j.nmd.2017.01.006.

    PMID: 28190646
  6. 6

    Noninvasive ventilation and laser-assisted unilateral posterior cordotomy as novel multidisciplinary approaches for Charcot-Marie-Tooth disease 4B vocal cord paralysis: a case report.

    Tabatabaii SA, Kianparsa J, Zavareh MHG, et al.

    Journal of medical case reports 2024; (18(1)):401 doi:10.1186/s13256-024-04742-6.

    PMID: 39217382
  7. 7

    Charcot-Marie-Tooth disease: A case report initially manifested by bilateral vocal cord paralysis.

    Mirlohi SH, Tajfirooz S, Rouhi M

    Respiratory medicine case reports 2025; (53()):102154 doi:10.1016/j.rmcr.2024.102154.

    PMID: 39886061
  8. 8

    Cochlear implantation in patients with Charcot-Marie-Tooth disease: two cases with a review of the literature.

    Song B, Cho H, Yun J, Moon IJ

    European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery 2024; (281(7)):3845-3851 doi:10.1007/s00405-024-08592-2.

    PMID: 38582814
  9. 9

    Prevalence and Auditory Characteristics of Auditory Neuropathy Spectrum Disorder in Adult Population with Sensory Neural Hearing Loss: A Hospital Based Study in South India.

    Muthukumar R, Jaya V, Vignesh SS, Thenmozhi K

    Indian journal of otolaryngology and head and neck surgery : official publication of the Association of Otolaryngologists of India 2023; (75(3)):1906-1911 doi:10.1007/s12070-023-03766-6.

    PMID: 37636754
  10. 10

    Auditory Neuropathy Spectrum Disorder in the White Sutton Syndrome.

    Musumano LB, Fancello V, Negossi L, et al.

    The journal of international advanced otology 2023; (19(3)):260-262 doi:10.5152/iao.2023.22877.

    PMID: 37272646
  11. 11

    Charcot-Marie-Tooth Disease Type 4C and Autosomal Dominant Heterozygous Ichthyosis Vulgaris, with Bilateral Hearing Loss: A Novel Association with Review of Literature.

    Chhajed M, Gunasekaran PK, Bhanudeep S, Saini L

    Journal of pediatric genetics 2024; (13(2)):110-115 doi:10.1055/s-0042-1759780.

    PMID: 38721572
  12. 12

    Charcot-Marie-Tooth disease type 4C in Norway: Clinical characteristics, mutation spectrum and minimum prevalence.

    Arntzen KA, Høyer H, Ørstavik K, et al.

    Neuromuscular disorders : NMD 2018; (28(8)):639-645 doi:10.1016/j.nmd.2018.06.004.

    PMID: 30001926
  13. 13

    Is Working Memory Compromised in Individuals with Sensorineural Hearing Loss with Auditory Neural Origin?

    Parthasarathy S, Shetty HN, Apeksha K

    Indian journal of otolaryngology and head and neck surgery : official publication of the Association of Otolaryngologists of India 2022; (74(Suppl 3)):3726-3732 doi:10.1007/s12070-021-02527-7.

    PMID: 36742781
  14. 14

    A nonsense TMEM43 variant leads to disruption of connexin-linked function and autosomal dominant auditory neuropathy spectrum disorder.

    Jang MW, Oh DY, Yi E, et al.

    Proceedings of the National Academy of Sciences of the United States of America 2021; (118(22)) doi:10.1073/pnas.2019681118.

    PMID: 34050020
  15. 15

    Auditory and Speech Outcomes of Cochlear Implantation in Children With Auditory Neuropathy Spectrum Disorder: A Systematic Review and Meta-Analysis.

    Bo D, Huang Y, Wang B, et al.

    The Annals of otology, rhinology, and laryngology 2023; (132(4)):371-380 doi:10.1177/00034894221092201.

    PMID: 35499129
  16. 16

    Cochlear Implantation in Children with Auditory Neuropathy: Meta-Analysis.

    Bernardes M, Costa C, Ramos H, et al.

    Audiology & neuro-otology 2024; (29(3)):167-180 doi:10.1159/000533298.

    PMID: 38016438

This page explains rare symptoms of Charcot-Marie-Tooth (CMT) disease for educational purposes only. Always consult your neurologist or primary care provider to evaluate new or worsening breathing or hearing symptoms.

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