Dysphagia is a common finding for patients being treated at rehabilitation facilities. Diseases of the central nervous system including stroke, Parkinson's disease and traumatic head injury are well-known causes of dysphagia.8
Other causes include structural lesions such as: a tumor, Zenker's diverticulum, congenital laryngeal web and thyroid hyperplasia, psychological problems, fibrosis due to radiation, and surgery involving the head and neck.5
In one study regarding the incidence of aspiration in acute stage stroke patients, an evaluation with a video fluoroscopic swallowing study showed aspiration in 51% of patients directly after the onset, 27% after one week and 8% after six months.8
This implies that dysphagia improves as time passes.8
Moreover, dysphagia in patients with stroke involving bilateral hemispheres is reported to be more severe and requires a longer period of time for recovery than stroke involving the unilateral hemisphere.8
In this case of unilateral stroke, dysphagia showed no improvement even after ten weeks. Therefore, although the patient had a definite history of stroke, other causes of dysphagia should be taken into consideration.
The retropharyngeal space is bordered anteriorly by pharyngeal muscle and fascia, and posteriorly by prevertebral fascia.9
This space includes no anatomically significant structures other than lymph nodes. These lymph nodes receive most lymphatic fluid from the head and neck, and degenerate after six years of age.10
Therefore there is a decreased incidencs of retropharyngeal abscess in adults. On the other hand, unlike adults, even healthy children are prone to a retropharyngeal abscess occurrence caused by upper respiratory infection, otitis media, pharyngitis and sinusitis. In adults, a retropharyngeal abscess usually occurs after dental treatment, trauma, swallowing of a foreign body, or are accompanied by underlying diseases leading to an immunocompromised state such as diabetes mellitus, malignant tumor and alcoholism.7
In this case, the patient had a history of diabetes mellitus, but the blood glucose level was well controlled, and there was no remarkable evidence of an immune disorder. Moreover, there were no predisposing factors like swallowing of a foreign body or surgical trauma such as a tracheostomy. Although surgery was performed for intracerebral hemorrhage, there were no signs of wound infection. In summary, there were no definite preceding causes for retropharyngeal abscess.
Possible symptoms caused by retropharyngeal abscess in adults include sore throat, dysphagia, cervical pain and rarely, airway obstruction. On diagnostic methods, a laryngoscopy may show normal results. Therefore lateral cervical X-ray imaging should be taken for the evaluation of retropharyngeal edema, and if a suspicious lesion is identified, a cervical CT or MRI examination must be performed in order to confirm the presence of an abscess and moreover, the predisposing factors.8
In this case, the patient had dysphagia and cervical pain. Retropharyngeal edema was identified on video fluoroscopic swallowing study performed for the purpose of evaluating dysphagia. Abnormal findings were present on laryngoscopy as well, and a cervical CT and MRI were carried out.
The causing organisms commonly reported are: group A β-hemolytic streptococci and staphylococcus aureus. Since gram negative bacilli and Mycobacterium tuberculosis could also be the causing organisms, a culture study along with additional examination for tuberculosis should be taken into consideration. Until the exact causing organism is verified, administration of broad-spectrum antibiotics is recommended.7
In this case, staphylococcus aureus was identified by culture study, and spondylitis was associated, which improved after the administration of intravenous Cefazolin 2 g every eight hours for eight weeks.
We presented a case of dysphagia caused by retropharyngeal abscess, rarely reported in adults to this day.