Sustained shoulder elevation posture: an under-recognized functional movement disorder phenotype

Area of Science:

• Neurology
• Movement Disorders
• Functional Neurological Symptom Disorder

Background:

• Sustained shoulder elevation postures are occasionally reported as variants of dystonia or post-traumatic movement disorders.
• This specific motor abnormality has not been well-characterized in medical literature.

Purpose of the Study:

• To assess the clinical records of patients with sustained or fixed shoulder elevation.
• To investigate the phenomenology, treatment response, and precipitants of this condition.
• To identify similar cases in existing literature.

Main Methods:

• Retrospective assessment of patient records from a movement disorders registry.
• Neurophysiologic, genetic, and neuropsychologic testing.
• PubMed search for similar case presentations.

Main Results:

• Six patients presented with sustained shoulder elevation, often involving adjacent regions and accompanied by pain.
• Two patients reported preceding local trauma; onset was acute or gradual.
• Poor response to oral medications and botulinum neurotoxin; deep brain stimulation ineffective in one patient.
• Motor cortex stimulation provided partial/temporary improvement in two patients.
• All patients diagnosed with functional movement disorder and functional neurological symptom (conversion) disorder.
• Literature search identified 75 similar cases, 75% preceded by minor trauma.
• The condition responded poorly to conventional treatments like oral medications, botulinum neurotoxin, or physical therapy.

Conclusions:

• Sustained shoulder elevation represents a recognizable syndrome within functional neurological symptom disorder.
• The condition is often preceded by trauma and shows poor response to standard treatments.
• This phenomenology has significant diagnostic and prognostic implications for patient care.