Muteness or mutism () is defined as an absence of speech while conserving or maintaining the ability to hear the speech of others. Mutism is typically understood as a person's inability to speak, and commonly observed by their family members, caregivers, teachers, doctors or speech and language pathologists. It may not be a permanent condition, depending on the cause, which might be physical, medical,

organic Organic may refer to: * Organic, of or relating to an organism, a living entity * Organic, of or relating to an anatomical organ Chemistry * Organic matter, matter that has come from a once-living organism, is capable of decay or is the product ...

psychological Psychology is the scientific study of mind and behavior. Psychology includes the study of conscious and unconscious phenomena, including feelings and thoughts. It is an academic discipline of immense scope, crossing the boundaries bet ...

, developmental,

neurological Neurology (from el, νεῦρον (neûron), "string, nerve" and the suffix -logia, "study of") is the branch of medicine dealing with the diagnosis and treatment of all categories of conditions and disease involving the brain, the spinal c ...

or traumatic. A specific

physical disability A physical disability is a limitation on a person's physical functioning, mobility, dexterity or stamina. Other physical disabilities include impairments which limit other facets of daily living, such as respiratory disorders, blindness, epil ...

communication disorder A communication disorder is any disorder that affects an individual's ability to comprehend, detect, or apply language and speech to engage in dialogue effectively with others. The delays and disorders can range from simple sound substitution to t ...

can be diagnosed. Loss of previously normal speech (

aphasia Aphasia is an inability to comprehend or formulate language because of damage to specific brain regions. The major causes are stroke and head trauma; prevalence is hard to determine but aphasia due to stroke is estimated to be 0.1–0.4% in ...

) can be due to accidents, disease, or surgical complication; it is rarely for psychological reasons. Treatment or management also varies by cause, determined after a speech assessment. Treatment can sometimes restore speech. If not, a range of assistive and augmentative communication devices are available.

Organic causes

Organic causes of mutism may stem from several different sources. One cause of muteness may be problems with the physiology involved in speech, for example, the mouth or tongue. Mutism may be due to apraxia, that is, problems with coordination of muscles involved in speech. Another cause may be a medical condition impacting the physical structures involved in speech, for example, loss of voice due to the injury, paralysis, or illness of the

larynx The larynx (), commonly called the voice box, is an organ in the top of the neck involved in breathing, producing sound and protecting the trachea against food aspiration. The opening of larynx into pharynx known as the laryngeal inlet is about ...

. Anarthria is a severe form of

dysarthria Dysarthria is a speech sound disorder resulting from neurological injury of the motor component of the motor–speech system and is characterized by poor articulation of phonemes. In other words, it is a condition in which problems effective ...

. The coordination of movements of the mouth and tongue or the conscious coordination of the lungs are damaged. Neurological damage due to

stroke A stroke is a disease, medical condition in which poor cerebral circulation, blood flow to the brain causes cell death. There are two main types of stroke: brain ischemia, ischemic, due to lack of blood flow, and intracranial hemorrhage, hemorr ...

may cause loss or impairment of speech, termed

. Neurological damage or problems with development of the area of the brain involved in speech production,

Broca's area Broca's area, or the Broca area (, also , ), is a region in the frontal lobe of the dominant hemisphere, usually the left, of the brain with functions linked to speech production. Language processing has been linked to Broca's area since Pier ...

, may cause muteness. Trauma or injury to Broca's area, located in the left inferior

frontal cortex The frontal lobe is the largest of the four major lobes of the brain in mammals, and is located at the front of each cerebral hemisphere (in front of the parietal lobe and the temporal lobe). It is parted from the parietal lobe by a groove be ...

of the brain, can cause muteness. Muteness may follow brain surgery. For example, there is a spectrum of possible neurobehavioural deficits in the posterior fossa syndrome in children following cerebellar

tumor A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

surgery.

Psychological causes

When children do not speak, psychological problems or emotional stress, such as

anxiety Anxiety is an emotion which is characterized by an unpleasant state of inner turmoil and includes feelings of dread over anticipated events. Anxiety is different than fear in that the former is defined as the anticipation of a future threat wh ...

, may be involved. Children may not speak due to selective mutism. Selective mutism is a condition in which the child speaks only in certain situations or with certain people, such as close family members. Assessment is needed to rule out possible illness or other conditions and to determine treatment. Prevalence is low, but not as rare as once thought. Selective mutism should not be confused with a child who does not speak and cannot speak due to physical disabilities. It is common for symptoms to occur before the age of five. Not all children express the same symptoms. Selective mutism may occur in conjunction with

autism spectrum disorder The autism spectrum, often referred to as just autism or in the context of a professional diagnosis autism spectrum disorder (ASD) or autism spectrum condition (ASC), is a neurodevelopmental condition (or conditions) characterized by difficulti ...

or other diagnoses.

Differential diagnosis In healthcare, a differential diagnosis (abbreviated DDx) is a method of analysis of a patient's history and physical examination to arrive at the correct diagnosis. It involves distinguishing a particular disease or condition from others that p ...

between selective mutism and language delay associated with autism or other disorders is needed to determine appropriate treatment. Adults who previously had speech and subsequently ceased talking may not speak for psychological or emotional reasons, though this is rare as a cause for adults. Absence or paucity of speech in adults may also be associated with specific psychiatric disorders.

Developmental and neurological causes

Absence of speech in children may involve communication disorders or language delays. Communication disorders or developmental language delays may occur for several different reasons. Language delays may be associated with other developmental delays. For example, children with

Down syndrome Down syndrome or Down's syndrome, also known as trisomy 21, is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21. It is usually associated with physical growth delays, mild to moderate intellectual d ...

often have impaired language and speech. Children with

autism The autism spectrum, often referred to as just autism or in the context of a professional diagnosis autism spectrum disorder (ASD) or autism spectrum condition (ASC), is a neurodevelopmental condition (or conditions) characterized by difficulti ...

, categorized as a neurodevelopmental disorder in the DSM-V, often demonstrate language delays.

Treatment

Evaluation of children with language delays is necessary to determine whether the language delay was caused by another condition. Examples of such conditions are autism spectrum disorder, hearing loss and apraxia. The manner of treatment depends on the diagnosed condition. Language delays may impact expressive language, receptive language, or both. Communication disorders may impact articulation, fluency (

stuttering Stuttering, also known as stammering, is a speech disorder in which the flow of speech is disrupted by involuntary repetitions and prolongations of sounds, syllables, words, or phrases as well as involuntary silent pauses or blocks in which the ...

) and other specified and unspecified communication disorders. For example, speech and language services may focus on the production of speech sounds for children with

phonological Phonology is the branch of linguistics that studies how languages or dialects systematically organize their sounds or, for sign languages, their constituent parts of signs. The term can also refer specifically to the sound or sign system of a ...

challenges. Intervention services and treatment programs have been specifically developed for autistic children with language delays. For example, pivotal response treatment is a well-established and researched intervention that includes family participation. Mark Sundberg's verbal behavior framework is another well-established assessment and treatment modality that is incorporated into many applied behavior analysis (ABA) early intervention treatment programs for young children with autism and communication challenges. Treatment for absence of speech due to apraxia, involves assessment, and, based on the assessment,

occupational therapy Occupational therapy (OT) is a global healthcare profession. It involves the use of assessment and intervention to develop, recover, or maintain the meaningful activities, or ''occupations'', of individuals, groups, or communities. The field of ...

physical therapy Physical therapy (PT), also known as physiotherapy, is one of the allied health professions. It is provided by physical therapists who promote, maintain, or restore health through physical examination, diagnosis, management, prognosis, pat ...

, and/or

speech therapy Speech is a human vocal communication using language. Each language uses phonetic combinations of vowel and consonant sounds that form the sound of its words (that is, all English words sound different from all French words, even if they are th ...

. Treatment for selective mutism involves assessment, counseling, and positive supports. Treatment for absence of speech in adults who previously had speech involves assessment to determine cause, including medical and surgery related causes, followed by appropriate treatment or management. Treatment may involve counseling, or rehabilitation services, depending upon cause of loss of speech.

Management

Management involves the use of appropriate assistive devices, called

alternative and augmentative communication Augmentative and alternative communication (AAC) encompasses the communication methods used to supplement or replace speech or writing for those with impairments in the production or comprehension of spoken or written language. AAC is used by t ...

s. Suitability and appropriateness of modality will depend on users' physical abilities and cognitive functioning. Augmentative and alternative communication technology ranges from elaborated software for tablets to enable complex communication with an auditory component to less technologically involved strategies. For example, a common method involves the use of pictures that can be attached to velcro strips to create an accessible communication modality that does not require the cognitive or fine motor skills needed to manipulate a tablet. Speech-generating devices can help people with speech deficiencies associated with medical conditions that affect speech, communication disorders that impair speech, or surgeries that have impacted speech. Speech-generating devices continue to improve in ease of use.

References