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

Abstract

Patients with sustained shoulder elevation postures were observed over time in our movement disorders clinic and occasionally reported in literature as variants of dystonia or post-traumatic movement disorders. We retrospectively assessed the clinical records of patients in our movement disorders registry with sustained or fixed shoulder elevation. Their clinical phenomenology, response to treatment and precipitants were investigated. The patients underwent neurophysiologic, genetic and neuropsychologic tests. A PubMed search of cases with similar presentation was performed. Six patients fulfilled the inclusion criteria. Their phenomenology showed a sustained postural abnormality with elevation of one shoulder that often involves neighbouring regions; pain was a common accompanying feature; there were no alleviating manoeuvres, mirror or overflow phenomena. A recent preceding local trauma was reported by two patients; the onset was acute or gradual, progression was stable after initial worsening. There was poor benefit from oral medications; botulinum neurotoxin treatment improved pain and had little influence on postural abnormalities. Deep brain stimulation was ineffective in one patient; motor cortex stimulation caused partial or temporary improvement in two. All the patients received a diagnosis of functional movement disorder and met diagnostic criteria for functional neurological symptom (conversion) disorder with abnormal movements. The search strategies identified 19 publications reporting 75 similar cases, 75% of which were preceded by a minor traumatic injury. The motor abnormality responded poorly to oral medications, botulinum neurotoxin or physical therapy. We expand here on a peculiar phenomenology of sustained or fixed shoulder elevation that represents a recognizable syndrome with diagnostic and prognostic implications.