Progressive dysphagia secondary to cervical osteophytosis due to diffuse idiopathic skeletal hyperostosis (DISH)

Abstract

Diffuse idiopathic skeletal hyperostosis (DISH) is a non-inflammatory systemic disease characterised by ossification of ligaments and entheses. Although it is usually asymptomatic, in its cervical localisation it can cause dysphagia secondary to oesophageal compression or functional limitation due to ankylosis. We present the case of a 58-year-old male with progressive dysphagia of three years' evolution, with an EAT-10 score of 34/40. Surgical resection of the impressive osteophyte formation was performed by an anterior cervical spine approach and precision drilling. Within a few weeks, there was a reported progressive improvement and complete resolution of the symptoms. The pathophysiological mechanisms involved and current recommendations on surgical indications, prognosis and follow-up are discussed. Awareness of this therapeutic option is paramount in non-surgical specialties, and interdisciplinary discussion is recommended.

Introduction

Diffuse idiopathic skeletal hyperostosis (DISH), or Forestier's disease, is a non-inflammatory systemic condition characterised by pathological ossification of the spinal ligaments, especially the anterior longitudinal ligament (ALL) [1]. This disease affects 3.9–35% of the general population, with higher prevalence in men over the age of 50 and a strong association with comorbidities, including obesity, type 2 diabetes, hypertension and metabolic syndrome.

Radiographically, DISH is defined according to the Resnick and Niwayama criteria [2]: flow-like ossification of the anterolateral aspect of at least four contiguous vertebral bodies, with preservation of the intervertebral space and absence of ankylosis in the apophyseal and sacroiliac joints. Although it typically affects the thoracic spine, cervical involvement can cause significant clinical symptoms due to proximity to critical structures such as the oesophagus and trachea [3].

Most cases of cervical DISH are asymptomatic; however, the formation of large anterior osteophytes can cause dysphagia, dysphonia, dyspnoea and even airway obstruction [4]. It is estimated that up to 10% of patients with cervical osteophytes may develop dysphagia, compromising the patient's quality of life and even nutritional status [5]. Dysphagia can be evaluated with clinical detection tools such as the EAT-10 (Eating Assessment Tool-10) questionnaire, comprising 10 items that assess symptom severity. Each item is scored from 0 (no problem) to 4 (severe problem), with a maximum total score of 40. A result ≥3 suggests the presence of clinical dysphagia and the need for further evaluation [6].

Initial treatment is conservative and includes dietary modifications, speech therapy rehabilitation and anti-inflammatories [5]. When these measures fail or the symptoms worsen, surgical resection of the cervical osteophytes using an anterior approach is considered the treatment of choice [7].

Case report

A 58-year-old man, with a body mass index (BMI) of 25.8 and no relevant medical history, presented with progressive difficulty in the ingestion of solids and liquids over the previous three years. He reported progressive weight loss. There was no history of previous cervical surgery. In the initial evaluation, the score on the EAT-10 scale was 34/40, indicating severe dysphagia.

The neurological examination was normal. A lateral X-ray of the cervical spine demonstrated the formation of a prominent anterior osteophyte spanning the C3-C6 levels. Computed tomography confirmed the presence of a 9 mm anterolateral bone mass compressing the posterior aspect of the oesophagus together with displacement of the trachea anteriorly (Fig. 1). The diagnosis of DISH was established according to Resnick's radiographic criteria [2]: flowing ossifications within four or more contiguous vertebrae with preserved intervertebral disc space and lack of apophyseal joint ankylosis or sacroiliac involvement. The differential diagnosis of ankylosing spondylitis was ruled out based on these radiological features as well as the absence of sacroiliac joint involvement, together with the absence of clinical markers and HLA-B27 negativity.

Figure 1.

(A) Preoperative cervical computed tomography (CT), sagittal plane. A 9 mm-thick anterior cervical osteophyte is observed extending from C3 to C5, with signs of an incipient osteophyte at C6; (B) Postoperative lateral cervical X-ray obtained on the first postoperative day. Complete resolution of the anterior cervical osteophyte is evident. Prevertebral soft tissue swelling is also observed; the dysphagia subsided over the ensuing few weeks.

Conservative management with dietary modification (soft and blended diet with adequate intake of fluids) for 6 months, and medical management with non-steroidal inflammatory drugs and proton pump inhibitors for 3 months, were attempted with unsustained relief of the dysphagia. The patient was then referred to the Neurosurgery department and a decision was made to proceed with surgery. A Smith-Robinson type right anterolateral cervical spine approach was used, with drilling of the anterior osteophyte. The landmarks for the drilling were the C2-C3 disc, which was the uppermost limit, and the C6 osteophyte, which was the lowest point of the drilling (Fig. 2). X-rays were performed during the surgery to provide guidance. The patient had no intraoperative incidents. In the immediate postoperative period, dysphagia initially persisted, attributed to postoperative oedema of the soft tissues, with no signs of oesophageal injury or neurological complications.

Figure 2.

Intraoperative view of the anterior cervical approach. (A) Exposure of the osteophyte, draped over levels C3–C5, prior to drilling. (B) During drilling. The upper limit of the resection is visible cranially, corresponding to the C2–C3 disc space.

Over the following weeks, the patient showed progressive clinical improvement, with complete resolution of the dysphagia one month after the operation. At the three-month check-up, the EAT-10 score was 2/40. No signs of recurrence were observed in the control image.

Discussion

Dysphagia associated with DISH of the cervical spine is a rare but clinically significant condition with potential nutritional and respiratory implications. Although mechanical compression of the oesophagus by anterior osteophytes is the most described pathogenic mechanism [1, 3, 5], recent studies have pointed out that it may not be the only determining factor.

It has been proposed that ankylosis of the cervical segments, especially at the lower levels, also plays an important role in the genesis of dysphagia. This ankylosis can restrict physiological cervical flexion, which negatively affects the mechanics of swallowing by preventing the correct movement of the laryngeal and pharyngeal structures [8]. This hypothesis is reinforced by the observation that, after surgery, not only does the score on scales such as the EAT-10 improve, but also the functional cervical angles (C2–C7 & C2–C6a), with no changes in the upper levels (O–C2), which suggests a relationship between dysphagia and lower cervical mobility [8].

In addition to ankylosis, other contributing factors include local inflammation, soft tissue oedema, pharyngeal muscle spasm and possible disorders in epiglottic movement [5, 9]. In advanced or chronic phases, there may also be periesophageal fibrosis and recurrent laryngeal nerve neuropathy, making it even more difficult to recover swallowing function.

In the illustrative case presented, the patient experienced progressive improvement after resection of the anterior osteophyte, although mild dysphagia persisted in the immediate postoperative period, probably secondary to postoperative inflammatory soft tissue oedema, a common finding described in the literature [10]. The above surgical approach was effective, and no complications were recorded. Direct resection of the osteophyte, without fusion, has been shown to be effective in most series, although the need for fusion will depend on the presence of cervical instability, the presence of a radicular compression and presence of pain [7].

With regard to recurrence, several studies report a re-ossification rate of up to 1–2 mm/year, with the possibility of symptomatic relapse in a period of 10 to 11 years, especially in the case of incomplete resections or in the absence of follow-up [10]. Some authors have suggested the use of NSAIDs or even prophylactic radiotherapy as a strategy to reduce re-ossification, although there is no robust evidence to support its efficacy in the cervical spine [7].

A prolonged period of dysphagia before surgery has been identified as being associated with poorer functional outcomes, probably due to the onset of irreversible structural changes in the soft tissues and neuromuscular dysfunction. For this reason, several authors advocate early surgical intervention, ideally within 72 months of the onset of symptoms, as a strategy to optimise results.

Finally, multidisciplinary management, including postoperative speech rehabilitation, postural education and long-term clinical-radiological follow-up, is essential to maximise functional recovery and prevent complications [3]. In selected cases, it may be necessary to assess the coexistence of cricopharyngeal dysfunction, which would justify combined techniques such as cricopharyngeal myotomy together with osteophysectomy [5].

Conclusion

Cervical DISH should be considered in the differential diagnosis of chronic dysphagia, especially in men older than 50 or those with metabolic risk factors. Symptoms do not depend exclusively on the size of the osteophyte, but also on functional factors such as cervical ankylosis or periesophageal inflammation. In patients with severe dysphagia which is refractory to conservative treatment, surgical resection via an anterior approach is a safe and effective option. Long-term clinical and radiological follow-up is essential, given the possibility of progressive re-ossification.

Conflict of interest

The authors have no conflicts of interest.

Funding

No funding was received for this study.

Ethical approval

No ethical approval was required for a case report.

Consent

The patient’s expressed written consent has been obtained for this manuscript.

Guarantor

AKD.