Yes. The cat got my tongue.

November 29, 2009 7:25 PM

What are some physiological causes for Mutism/Aphonia? I'm looking for reasons that are organic in origin (so no 'selective mutism' or other related disorders). I'm also looking for reasons that aren't comorbid with another condition, such as Autism, Deafness, etc.

In doing some reading on Disability and the Media, Mutism seems to a disability that gets used in some places, particularly Anime - so much so that there's now a trope called the Cute Mute. Yet, mutism in real life seems to be rare. So, I'm wondering what could cause such a condition. (I'm also wondering why it seems to be used a lot in Anime, but that's the topic for another question!)

posted by spinifex23 to health & fitness (11 answers total)

It sometimes happens in children who are being treated for medulloblastomas (a brainstem cancer that happens primarily in children) or related cancers. In those cases I believe the mutism is due to damage to the cerebellum during surgery and/or radiotherapy. Individuals recover speech ability afterward.
posted by drmarcj at 7:46 PM on November 29, 2009

Yeah, following up on drmarcj's comment, I'm pretty sure any primary physiological reason will be some sort of brain damage. To frontal lobe, cerebellum, thalamus or brain stem (regions that are "speech centers" or major relay centers).
posted by gaspode at 8:05 PM on November 29, 2009

A woman I love dearly is mute. In her case, the probable cause is uterine environment and fetal brain development - essentially, her mother is suspected to have taken a lot of drugs while pregnant with her. She is not deaf, and can communicate in multiple languages, although occasionally has spelling difficulties with words that are "on the tip of her tongue", not being able to sound out phonemes.

She's what I call "functionally autistic" - she's an excellent writer, and the brightest woman I've ever met, but is hypersensitive to sensory input, and she finds it difficult to relate to other people. It's unclear if this is tied to the muteness, or is a product of it, or is completely separate.
posted by Bora Horza Gobuchul at 8:18 PM on November 29, 2009

Are you only looking for reasons that don't involve any outside causes? My boyfriend's friend was left mute from a car accident. I believe her injuries were to the neck.
posted by cmgonzalez at 8:21 PM on November 29, 2009

Bilateral damage to the recurrent laryngeal nerve, the inferior branch of the vagus nerve, can cause aphonia. The vagus nerve is responsible for much of the innervation of the muscles of the larynx. This can happen as a result of thyroid surgery gone less than perfect or a tumor in the chest or neck. Maybe trauma or a stroke as well? Then of course you have things like laryngectomies, though there are ways to produce voice afterward. Check out esophageal speech, which would really not fit in with the "Cute Mute" thing.
posted by zoey08 at 8:25 PM on November 29, 2009

I should clarify - outside causes are OK.

Thanks for all the answers so far, everyone!
posted by spinifex23 at 8:45 PM on November 29, 2009

Surgical damage to the active speech center (mid-brain, next to the left ear) can do that. I saw a documentary one time about a kid who had a brain tumor and the only way the surgeon could reach it was to cut through the speech center. After the kid woke up he couldn't speak any longer, and was intensely frustrated by it.

The reason the surgeon was willing to do that was that the redundant speech center on the right side of the brain turned on and picked up the load. Within a couple of years the kid could speak normally again.

I don't think that mutism really happens very often without any other condition. The vast majority of mutes are either deaf or have suffered some kind of brain damage, whether due to genetics, trauma, high fever, anoxia, or drugs.

There is one way that a kid can be mute without any kind of physical damage at all. It's the "wolf child" syndrome: a normal kid who is raised in an environment where he never hears human speech and never tries to speak himself.

This can, and has, also happened when deaf people have normal children and raise them in a deaf community without any outside contact. If a child with normal hearing is not exposed to human speech during the first year of life, certain critical brain development doesn't happen.
posted by Chocolate Pickle at 8:46 PM on November 29, 2009

While Schuyler isn't mute, she doesn't talk (much) without assistance. Here's some details about her Congenital Bilateral Perisylvian Syndrome.
posted by The corpse in the library at 9:01 AM on November 30, 2009

And apraxia can lead to problems speaking, or the inability to speak (again, not cute anime muteness).
posted by The corpse in the library at 9:02 AM on November 30, 2009

These are all great answers, thank you. And, the further away from "cute mute", the better! It always struck me as an unrealistic trope not rooted in reality.
posted by spinifex23 at 10:29 AM on November 30, 2009

Oh, I knew someone who didn't speak at all, because he'd lost his tongue in an accident when he was younger. (I didn't know him well, and don't have more details.)
posted by The corpse in the library at 10:34 AM on November 30, 2009