Proposal of a diagnostic algorithm for radiation-induced dropped head syndrome in long-term childhood cancer survivors based on a prospective study in a specialized clinical setting and a review of the literature

PURPOSE

To prospectively assess the incidence of Dropped Head Syndrome (DHS) in childhood cancer survivors (CCS) and to develop and evaluate a diagnostic algorithm for DHS.

METHODS

A systematic literature search for DHS in combination with neck radiotherapy (RT) exposure was performed. Analyses and a combination of the most common examination methods were integrated into a diagnostic algorithm. Almost all CCSs visiting the local late effects clinic between May 2020 and April 2022 were included in the study. CCS exposed to neck RT with doses ≥ 19 Gy received standardized clinical and neurological assessment and, in case of abnormal results, an MRI scan to confirm muscle atrophy.

RESULTS

Two hundred and five CCS were included of whom 41 received RT to the neck with ≥ 19 Gy. In the entire cohort and in the subgroup receiving RT, 2.4% and 12% of CCS were affected by DHS, respectively. Results of clinical and neurological assessment correlated well with MRI results. Neck circumference and neck/thigh ratio were lower after neck RT. Over 50% of CCS experienced neck disability and pain.

CONCLUSIONS

A relevant proportion of CCS exposed to neck RT is affected by DHS. High concordance of MRI results with the neurological examination supports the clinical value of the diagnostic algorithm. Measurement of neck circumference might be an easy tool for assessment of neck muscle atrophy in survivors at risk.

IMPLICATIONS FOR CANCER SURVIVORS

Integration of a diagnostic algorithm for DHS in standard long-term follow-up care facilitates diagnosis as well as initiation of early treatment and obviates the need for invasive examinations.

Dropped Head Syndrome: An Update on Etiology and Surgical Management

» Dropped head syndrome is a group of disorders with diverse etiologies involving different anatomical components of the neck, ultimately resulting in a debilitating, flexible, anterior curvature of the cervical spine. » Causes of dropped head syndrome include myasthenia gravis, amyotrophic lateral sclerosis, Parkinson disease, radiation therapy, and cumulative age-related changes. Idiopathic cases have also been reported. » Nonoperative treatment of dropped head syndrome includes orthotic bracing and physical therapy. » Surgical treatment of dropped head syndrome consists of cervical spine fusion to correct the deformity. » The limited data available examining the clinical and radiographic outcomes of surgical intervention indicate a higher rate of complications with the majority having favorable outcomes in the long term.

Late onset of dropped head syndrome following mantle radiation therapy for Hodgkin lymphoma

Dropped head syndrome (DHS) is a rare condition, characterised by weakness of the cervical paraspinal muscles with sagging of the head. It is usually seen in association with neurological disorders and rarely can follow radiotherapy. We report a case of a 54-year-old man survivor of Hodgkin lymphoma (HL), who developed DHS 28 years after radiotherapy. He was referred to our department due to progressive weakness and atrophy of cervical paraspinal and shoulder girdle musculature. Physical and neurophysiological examination, electromyography and MRI confirmed the diagnosis of DHS. In the following years, there was no progression of symptoms.

Radiation-induced camptocormia and dropped head syndrome: Review and case report of radiation-induced movement disorders

BACKGROUND

In recent years, camptocormia and dropped head syndrome (DHS) have gained attention as particular forms of movement disorders. Camptocormia presents with involuntary forward flexion of the thoracolumbar spine that typically increases during walking or standing and may severely impede walking ability. DHS is characterized by weakness of the neck extensors and a consecutive inability to extend the neck; in severe cases the head is fixed in a "chin to chest position." Many diseases may underlie these conditions, and there have been some reports about radiation-induced camptocormia and DHS.

METHODS

A PubMed search with the keywords "camptocormia," "dropped head syndrome," "radiation-induced myopathy," "radiation-induced neuropathy," and "radiation-induced movement disorder" was carried out to better characterize radiation-induced movement disorders and the radiation techniques involved. In addition, the case of a patient developing camptocormia 23 years after radiation therapy of a non-Hodgkin's lymphoma of the abdomen is described.

RESULTS

In total, nine case series of radiation-induced DHS (n = 45 patients) and-including our case-three case reports (n = 3 patients) about radiogenic camptocormia were retrieved. Most cases (40/45 patients) occurred less than 15 years after radiotherapy involving extended fields for Hodgkin's disease.

CONCLUSION

The use of wide radiation fields including many spinal segments with paraspinal muscles may lead to radiation-induced movement disorders. If paraspinal muscles and the thoracolumbar spine are involved, the clinical presentation can be that of camptocormia. DHS may result if there is involvement of the cervical spine. To prevent these disorders, sparing of the spine and paraspinal muscles is desirable.

Clinical and laboratory findings of 21 patients with radiation-induced myopathy

BACKGROUND

Limited data are available on radiation-induced myopathy (RIM) in adult cancer survivors.

METHODS

We retrospectively reviewed the clinical, electrophysiological, serological, radiological and pathological findings of patients with RIM seen in the neurology clinic over a 11-year period (2002-2013).

RESULTS

Out of 251 patients with radiotherapy-induced neuromuscular complications, 21 had RIM (11 men and 10 women). Cancers included: Hodgkin's lymphoma (13), non-Hodgkin's lymphoma (one), pinealoblastoma (one), tongue (two), nasopharyngeal (one), thyroid (one) and testicular cancer (two). Various radiotherapy protocols were used but all patients received neck and upper torso radiation. The mean latency between radiation exposure and onset of RIM was 15 years (range 2-45 years). The most common presentation was head drop (43%) followed by neck pain (38%). Axial (86%) and periscapular (81%) muscle weakness and atrophy were frequent findings. Two patients died in follow-up from hypercapnic respiratory failure secondary to neuromuscular weakness. Serum creatine kinase values were usually normal or slightly elevated. EMG revealed predominantly myopathic changes in the axial and periscapular muscles. Half of the muscle biopsies (6/12) showed myopathic changes; increased connective tissue elements were observed in seven of eight muscle biopsies performed in the irradiated field; and mitochondrial dysfunction in two.

CONCLUSIONS

RIM is a potential long-term neuromuscular adverse effect of radiation exposure in Hodgkin's disease and other types of cancer manifesting predominantly as head drop and can be fatal due to neuromuscular respiratory failure. Improved radiotherapy protocols might reduce the risk of RIM and other radiation-induced neuromuscular complications.

Pedicle subtraction osteotomy for the treatment of chin-on-chest deformity in a post-radiotherapy dropped head syndrome: a case report and review of literature

PURPOSE

Chin-on-chest deformity is a rare and severe condition mostly related with ankylosing spondylitis, traumas and/or cervical spine surgery. We present a case of 69 years old woman with a rare form of chin-on-chest secondary to dropped head syndrome (DHS), developed after radiotherapy for Hodgkin disease. In addition, we reviewed the few publications about this specific condition; management and surgical treatment of DHS are discussed.

METHODS

We performed a pedicle subtraction osteotomy (PSO) and stabilization through a posterior approach. Intraoperative monitoring using motor and somatosensory evoked potentials and wake-up test were carried out.

RESULTS

At 19th month follow-up, the patient reported a significant improvement of cervical pain, dysphagia and respiratory difficulty and a complete restoration of the neurological impairment. The achieved correction was successful and the patient was very satisfied by the restoration of forward gaze.

CONCLUSIONS

DHS is a very rare post-radiotherapy complication; there is lack of evidences in literature about its management. The only definitive treatment seems to be surgical intervention. PSO is a valid therapeutic option when fixed chin-on-chest deformity occurs; although it is a demanding technique and it presents high rate of complications, the actual neurological monitoring methods provide more intraoperative safety.