The potential efficacy of serotonin noradrenaline reuptake inhibitor duloxetine in dropped head syndrome: A case report and review of the literature

A 78 year-old female presented with dropped head syndrome (DHS). Three months before her initial visit to our hospital, the patient noticed a pronounced flexion of her head and neck with subsequent deterioration of symptoms, which included neck pain, difficulty with forward gaze, and gait disturbance. Cervical radiographs demonstrated scoliotic and kyphotic changes, and her symptom deteriorated over time, especially in the standing position. Duloxetine was administered for her low back pain because nonsteroidal anti-inflammatory drugs deemed ineffective. The patient demonstrated marked improvements in both radiographic and clinical appearances after 4 months. Her neck pain decreased from 8 to 2 out of 10 in the Numeric Rating Scale, and her symptoms such as difficulty with forward gaze and gait disturbance had also resolved. Duloxetine is a serotonin noradrenaline reuptake inhibitor that is usually used for chronic musculoskeletal pain, neuropathic pain, or depression. In this report, we present another potential application of duloxetine in the treatment of DHS. The following possibilities were considered for the improved outcomes: (1) pain relief may have helped the patient feel comfortable enough to move her neck, and (2) we suppose that serotonin and noradrenaline reuptake may contribute to the improvement of DHS, because there might be a potential disequilibrium of neurotransmitters such as serotonin, dopamine and noradrenaline in DHS patients. Although further investigation is needed to clarify the mechanism, duloxetine should be considered as one of the optional treatments for DHS.