The Occurrence of Dropped Head Syndrome After a Cervical Medial Branch Nerve Block in a Patient With Cervicothoracic Kyphotic Deformity: A Case Report

Abstract

Complications from medial branch blocks (MBBs) are rare when following proper procedural protocol. Dropped head syndrome (DHS) is characterized by profound muscle weakness in the cervical spine, resulting in a failure to maintain a level horizontal gaze and, in the worst cases, a chin-on-chest deformity. In this case report, we described DHS developing after cervical MBBs using short-acting anesthetic agents and subsequent management. A 69-year-old woman with a previous C6-C7 anterior cervical discectomy and fusion (ACDF) underwent bilateral posterior cervical MBBs targeting the C4-C5 and C5-C6 levels. Immediately following the injection, she reported a sudden inability to lift her head and was subsequently diagnosed with DHS. This condition continued with minimal improvement for over six months. After weighing the risks, the patient elected to avoid surgery, and she was provided a soft cervical collar and prescribed physical therapy. DHS is a debilitating condition more commonly associated with neurodegenerative conditions and inflammatory myopathy, which has received limited attention due to its rarity as a complication of cervical radiofrequency neurotomy. Surgery for this condition, when considered, typically involves long-segment posterior cervical instrumented fusion. Undergoing such a surgery is a complicated discussion that should consider patient clinical factors and preferences. The clinical impact of loss of strength in paraspinal musculature in this patient population is clearly deserving of further study.

Keywords: cervical spine; deformity; dropped head syndrome; kyphosis; medial branch nerve block.

Figure 1. T2-weighted MRI of patient’s mid-sagittal cervical spine approximately two months before medial branch block injection.

Figure 2. (a) Full-length sagittal photo of the patient upon physical examination; (b) photo of manual extension of the cervical spine could demonstrate the patient’s level gaze.

Figure 3. (a) X-ray of patient in relaxed lateral position for initial clinic X-rays six weeks post DHS onset; (b) X-ray of patient in extension for initial clinic visit six weeks post DHS onset.

Figure 4. (a) X-ray of patient in extension four months post DHS onset; (b) X-ray of patient in flexion four months post DHS onset.

Figure 5. X-ray of patient in relaxed lateral position six months post DHS onset.