Stereotyped Posture
A stereotyped posture is an abnormal, non-adaptive posture that is rigidly maintained, distinguished from a manneristic posture, which is an odd, stilted exaggeration of a normal posture that is not rigidly held. Some stereotyped postures are dramatic and unmistakable, such as sitting with the head and body twisted at right angles to the vertical, while others, such as the psychological pillow or snout spasm, are more specific and recognisable patterns in their own right.
This has traditionally been distinguished from a manneristic posture mainly by rigidity: a mannerism is not rigidly preserved and represents an exaggeration of an otherwise normal posture, whereas a stereotyped posture is abnormal in itself and held fixed, though the book itself acknowledges that the exact point at which a postural mannerism becomes a true stereotypy can be difficult to judge.
Also known as
- Psychological pillow
- A stereotyped posture in which the patient lies with their head held a few inches off the pillow, maintained for hours; also seen in dementia.
- Snout spasm (Schnauzkrampf)
- A stereotyped posture in which the lips are thrust forward in a tubular manner; although it looks like a disorder of expression, it is best classified as a stereotyped posture.
Recognition features
- An abnormal, non-adaptive posture that is held rigidly, in contrast to the more flexible, merely exaggerated quality of a manneristic posture
- May be dramatic and unmistakable, such as a strikingly twisted body position, or more specific and named, such as the psychological pillow or snout spasm
- The psychological pillow involves holding the head a few inches above the pillow for hours at a time
- Snout spasm (Schnauzkrampf) involves the lips being held thrust forward in a tubular shape
Eliciting it at interview
- Observe the patient's resting posture over an extended period, since some stereotyped postures, like the psychological pillow, are maintained for hours and may not be obvious on brief observation
- Note whether an unusual posture is rigidly fixed (suggesting stereotypy) or a looser exaggeration of a normal position that shifts over time (suggesting a mannerism)
- Document the specific posture observed precisely, since named patterns such as the psychological pillow and snout spasm are recognised, clinically informative signs in their own right
Distinguishing features
- Differs from a manneristic posture by its rigidity and lack of adaptive purpose, whereas a manneristic posture remains a recognisable exaggeration of an ordinary posture
- Differs from perseveration of posture, in which the posture arose from an examiner's own passive manipulation or occurred fortuitously and is then maintained, whereas a stereotyped posture may be adopted and sustained spontaneously by the patient
- Also occurs in dementia, as well as catatonia, so is not specific to any single underlying diagnosis
Common misconceptions
- That any odd posture is automatically a stereotypy; the boundary between a mannerism and a true stereotypy depends on rigidity and duration, and can genuinely be difficult to judge
- That snout spasm is purely a disorder of facial expression; although it looks expressive, it is best classified and understood as a stereotyped posture
Related phenomena
Mannerisms · Perseveration of Posture · Involuntary Neurological Movement Signs
Diagnostically relevant to
Schizophrenia (catatonic presentations) (links open the DSM-5 Learning Lab)
Practice this
A patient spontaneously adopts and rigidly holds his head a few inches above the pillow for hours at a time, with no prompting or passive manipulation by anyone else. What is this? · An examiner passively raises a patient's arm into an awkward, uncomfortable position during examination; the patient then maintains that exact position for several minutes after being released, with no instruction to do so and no attempt to adopt it beforehand. Before revealing the answer: is this a stereotyped posture? · A patient is holding an abnormal, sustained muscular posture. Before revealing the answer, decide what distinguishes acute dystonia from a catatonic stereotyped posture. · A patient repeatedly performs an unusual movement. Before revealing the answer, decide what would tell a mannerism apart from a stereotyped posture. · A patient maintains an unusual posture for an extended period. Before revealing the answer, decide what distinguishes a stereotyped posture from perseveration of posture. · You suspect a patient shows a stereotyped posture. Before revealing the answer, decide how you would assess for this. · Explain why specific, named patterns like the psychological pillow and snout spasm are useful for clinicians to recognise by name.
Illustration
A patient with catatonic schizophrenia is observed lying in bed with her head held rigidly a few inches above her pillow for well over two hours, an uncomfortable-looking position she maintains without any apparent effort or complaint, resuming it again the following day after staff gently repositioned her.
References
- Casey, P. & Kelly, B. (2019). Fish's Clinical Psychopathology, 4th ed. Ch. 8, 'Motor Disorders'.