Motor and Verbal Perseveration
Motor perseveration is the senseless continuation of a goal-directed physical action well past the point at which it has already served its purpose, such as a patient continuing to put their tongue in and out after being told to stop. The same underlying pattern shows up in speech as a difficulty moving on from a word, phrase, or topic that has already served its purpose in the conversation, sometimes taking specific forms such as logoclonia or palilalia.
This has traditionally been divided, following systematic study, into three distinguishable types: compulsive repetition, in which the act continues until specifically countermanded by a new instruction; impairment of switching, in which the repetition continues even after a new task has been given; and ideational perseveration, in which words and phrases are repeated within the answer to a question. All three types have been found in both schizophrenia and dementia, though with different relative frequencies.
Also known as
- Logoclonia
- A specific speech pattern in which the last syllable of the last word is repeated, for example 'today-ay-ay-ay'.
- Palilalia
- A specific speech pattern in which the perseverated word is repeated with increasing frequency.
Recognition features
- A goal-directed physical action (for example, putting the tongue out and in) continues to be repeated after it has already achieved its purpose and after an instruction to stop
- In speech, a word, phrase, or theme from a previous point in the conversation persists into subsequent, unrelated responses
- May take the specific form of logoclonia (the last syllable of the last word repeated) or palilalia (the perseverated word repeated with increasing frequency)
- Can be classified as compulsive repetition, impairment of switching to a new task, or ideational perseveration of words and phrases within a single response
Eliciting it at interview
- Ask the patient to perform and then stop a simple repeated physical action, such as putting the tongue out and in, and observe whether the action continues after the instruction to stop
- Give a new task or question after a previous one and observe whether elements of the previous task intrude into the response to the new one
- Listen carefully for the specific speech patterns of logoclonia and palilalia, since these are distinctive and diagnostically informative forms of verbal perseveration
Distinguishing features
- Differs from the general form of verbal perseveration (an earlier answer intruding into a new, different question) by extending the same underlying difficulty to physical, goal-directed motor acts as well as speech
- Logoclonia and palilalia are distinguished from one another by exactly what repeats: the final syllable of the last word in logoclonia, versus the whole perseverated word repeated with increasing frequency in palilalia
- Compulsive repetition was found to be relatively more common in schizophrenia, while impairment of switching was relatively more common in dementia, though ideational perseveration occurred about equally in both
Common misconceptions
- That motor perseveration is simply forgetfulness about having already completed a task; the action or word persists actively rather than the person having merely lost track of what they were doing
- That all forms of perseveration are the same; the three-type classification and the specific patterns of logoclonia and palilalia reflect genuinely distinct underlying difficulties
Related phenomena
Perseveration · Perseveration of Posture
Practice this
After being asked to put her tongue out and told "thank you, that's enough," a patient continues moving her tongue in and out for several more seconds before stopping, seemingly unable to move straight on to the next instruction. What is this? · During a bedside cognitive assessment, a patient is asked to draw a series of five-pointed stars. After completing the first star correctly, he continues drawing additional star points well beyond the outline, unable to stop the pen even when reminded the task is complete. Before revealing the answer: is this motor perseveration? · A patient, asked a question about his name, answers correctly. Asked next what year it is, he again says his own name. Is this motor perseveration? · You want to test for motor perseveration at the bedside. Which single approach would most efficiently elicit it if it is present? · A patient continues a drawing task well past its completion despite a clear verbal instruction to stop. Why is this classified as motor perseveration rather than simple forgetfulness about the instruction?
Illustration
Asked to put his tongue out and then told to put it back in, a patient with catatonia does so correctly once, but then continues putting his tongue out and in repeatedly every few seconds for the next several minutes, seemingly unable to simply stop despite no further instruction being given.
References
- Casey, P. & Kelly, B. (2019). Fish's Clinical Psychopathology, 4th ed. Ch. 8, 'Motor Disorders'.