Thought & Speech

Mutism

Mutism is a complete loss of speech. It has many possible causes and presentations, ranging from a child who selectively refuses to speak in particular settings, to a dissociative loss of speech under psychological stress, to profound mutism accompanying catatonic stupor, to organic states in which mutism accompanies reduced consciousness.

This has traditionally been distinguished from severe motor aphasia by the fact that even very limited aphasic speech usually retains a few verbal stereotypies or expletives under emotional stress, whereas true mutism involves a complete absence of speech output.

Also known as

Elective (selective) mutism

A pattern, usually seen in children, of refusing to speak to certain people or in certain settings while speaking normally in others, such as a child who is mute at school but talkative at home.

Hysterical mutism

A relatively rare dissociative or conversion presentation of complete loss of speech; aphonia, a loss of voice rather than of the ability to form words, is a more common related hysterical speech disorder.

Akinetic mutism

Mutism occurring together with a profound lack of movement and a lowered level of consciousness, associated with lesions of the upper midbrain or posterior diencephalon.

Recognition features

• Complete absence of spoken speech, in a person otherwise capable of speaking
• May be selective to particular people or settings (in children), generalised and psychologically triggered, or accompany a catatonic or organic state
• The person may still communicate through gesture or writing, particularly in catatonic presentations
• Almost always present in catatonic stupor, though it can also occur as an isolated mannerism in catatonic patients who are not stuporous

Eliciting it at interview

• Establish whether the mutism is total or selective to particular people, places, or situations, since this distinction points toward quite different underlying causes
• Offer alternative means of communication, such as pencil and paper, and note whether the person makes use of them, since this can help distinguish catatonic mutism from other causes
• Assess level of consciousness and movement carefully alongside the absence of speech, since the combination of mutism with reduced alertness points toward an organic cause such as akinetic mutism

Distinguishing features

• Differs from severe motor aphasia, in which some verbal stereotypies or expletives are typically still produced even when vocabulary is severely restricted
• Differs from pure word-dumbness, in which the person cannot speak but can still read and write normally
• Akinetic mutism is distinguished from other forms by its combination with profound reduction in movement and a lowered level of consciousness, pointing to a specific organic cause

Common misconceptions

• That mutism always reflects a deliberate choice not to speak; in catatonic and organic presentations, the person may be entirely unable to produce speech despite being aware of their surroundings
• That a mute person cannot communicate at all; gesture and writing may remain available and should always be offered as an alternative

Related phenomena

Pure Word-Dumbness · Talking Past the Point (Vorbeireden)

Practice this

A patient produces no spoken speech at all over several days of observation, despite being otherwise physically capable of speaking, and communicates instead only through gesture and occasional handwritten notes. What is this? · Following a focal neurological event, a patient produces no speech at all, but reading comprehension and handwritten communication both remain entirely normal and unaffected. Before revealing the answer: is this simply mutism, with nothing more specific to say? · A patient's spoken output is severely reduced. Before revealing the answer, decide what distinguishes expressive aphasia from mutism. · A patient has stopped speaking entirely. Before revealing the answer, decide what distinguishes general mutism from the specific pattern of pure word-dumbness. · A patient's speech is markedly disrupted. Before revealing the answer, decide what distinguishes stammering (stuttering) from mutism. · A patient has not spoken for some time. Before revealing the answer, decide how you would assess this mutism further. · Explain why mutism is described as having "many possible causes and presentations" rather than being treated as a single, unified phenomenon.

Illustration

A woman in catatonic stupor has not spoken a single word in over twenty years, communicating instead through gesture and, occasionally, brief written notes when given a pencil and paper, having once explained decades earlier that her words were "too valuable to be given away."

References

• Casey, P. & Kelly, B. (2019). Fish's Clinical Psychopathology, 4th ed. Ch. 4, 'Disorders of Thought and Speech'.