The hidden dysphagia: Exploring dysphagia in acute cervical spinal cord injury
In many textbooks, the signs of dysphagia are clear: weakness of the tongue or face, prolonged chewing, coughing after drinks, wet, gurgly voice, drooling (1). So when these signs are absent during a clinical swallow evaluation, we can presume the swallow is safe and start a patient on an oral diet. However, when the same patient goes on to develop an aspiration pneumonia a couple of days later, do you question your decision?
The clinical presentation of dysphagia for many people following cervical spinal cord injury is often subtle or absent. A small number of papers report the incidence of dysphagia to be between 30% to 74% (2-4). In the absence of brain injury, the cause appears to be multi-factorial with neurological, mechanical and respiratory causes. Surgery is often required to repair the bony damage to the spinal column and prevent further spinal cord damage. To access the upper cervical structures, surgeons will often operate via an anterior lateral approach, moving the laryngeal and pharyngeal musculature to the side. There is an established body of literature that confirms the impact of anterior cervical spinal fixation surgery on the neurological innervation of the larynx and pharynx (5, 6), and this is often seen in the presentation of vocal cord palsies and sensory impairment. The addition of metalwork to augment any bony breaks may also impinge into the pharynx causing disruption to epiglottic retroflexion. Complete spinal injuries to C6 will often require invasive ventilation via tracheostomy (7) although the effect is still debated (8), together with altered airflow from assisted ventilation, these add to the disruption of swallowing (9).
For many people who sustain a cervical spinal cord injury they are relieved to be alive, despite needing a tracheostomy and ventilation. They will lack movement and sensation from the neck down but will be grateful for the ability of speech and language. Unlike many other neurological conditions dysphagia in this patient group does not present overtly. Silent aspiration is increasingly found to be a feature (10) and this will require further investigation to verify.
Although videofluoroscopy is often the gold standard assessment, there are challenges for this patient group as they may be bed-bound for many weeks and it does not offer the opportunity for sensory testing. We use Fiberoptic Endoscopic Evaluation of Swallowing (FEES) as the first assessment as it can be taken to the bedspace and be used in the current position of the patient. Our team have found it helpful to assess secretion management, pharyngeal sensation and airway sensitivity. Over the last twelve years, we have discovered undiagnosed vocal cord palsies, and identified poor and often absent sensation resulting in diffuse pooling of food, particularly of thick smooth consistencies, around the pharynx and even within the laryngeal vestibule, with no outward signs or wet voice. There were also definitive episodes of silent aspiration events with no changes to breathing pattern. This has been an education to my colleagues and I about the different type of swallowing problem spinal cord injury patients experience.
We perform a FEES on every cervical SCI patient, even if they have already started oral intake. Contrary to the usual order of consistencies we test, we have found that thin fluids tend to be better tolerated, with yoghurt and thickened fluids the worst due to poor pharyngeal clearance, resulting in potential late aspiration. Patients do better with more textured foods such as banana and biscuits, as it appears to provide more stimulation to the tongue and pharynx with better cohesion.
Apart from diet modification, these patients benefit from direct therapy which can be challenging as we are not targeting motor function as much as sensory function in the pharynx. Regular and intensive input is the key and can be a shared responsibility with carers and therapy staff. At our unit, we carry out a range of ‘swallow stimulation’ exercises targeting base of tongue and employing many of the principles of Facial Oral Tract Therapy (FOTT) REF often used with the head injury patient group.
Another therapy aim is to ensure every tetraplegic patient has a reliable form of communication, with physical access to other communication aids being a challenge. Our team work closely to monitor patents whilst they achieve ventilation with cuffless tube which then allows for leak speech (11), as well as utilising other laryngeal functions such as cough and throat clearing.
Speech and Language Therapists/Pathologists have a unique role with these patients, using our specialist skills to identify areas of weakness and definite strengths. Consequently, it is important for us to take patients through a therapy programme that will allow them the pleasures of oral intake and speech.
The reported experiences of many of my patients have directed me to designing the DAISY project – a study to identify Dysphagia following Acute cervIcal Spinal cord injurY. My research over the next three years will investigate the clinical decisions made by staff in relation to oral intake and tracheostomy management, as well as exploring the impact those decisions have on patients. My end goal is to develop a screening tool that will help to identify the risks of dysphagia in those with a cervical spinal cord injury. This will ensure prompt referral to SLT to provide targeted intervention and reduce the complications that many experience.
As one of my patients said “eating and drinking made things a little more normal again….”.
References
- Groher ME. Dysphagia: Diagnosis and Management
: Butterworth-Heinemann; 1997 1997-03-02. 384 p.
- Shem K, Castillo K, Wong S, Chang J. Dysphagia in individuals with tetraplegia: incidence and risk factors. Journal of Spinal Cord Medicine. 2011;34(1):85-92.
- Chaw E, Shem K, Castillo K, Wong SL, Chang J. Dysphagia and Associated Respiratory Considerations in Cervical Spinal Cord Injury. Topics in Spinal Cord Injury Rehabilitation. 2012;18(4):291-9.
- Ramczykowski T, Gruening S, Gurr A, Muhr G, Horch C, Meindl R, et al. Aspiration pneumonia after spinal cord injury. Placement of PEG tubes as effective prevention. Unfallchirurg. 2012;115(5):427-32.
- Riley LH, 3rd, Vaccaro AR, Dettori JR, Hashimoto R. Postoperative dysphagia in anterior cervical spine surgery. Spine (Phila Pa 1976). 2010;35(9 Suppl):S76-85.
- Kalb S, Reis MT, Cowperthwaite MC, Fox DJ, Lefevre R, Theodore N, et al. Dysphagia after anterior cervical spine surgery: incidence and risk factors. World Neurosurgery. 2012;77(1):183-7.
- McCully BH, Fabricant L, Geraci T, Greenbaum A, Schreiber MA, Gordy SD. Complete cervical spinal cord injury above C6 predicts the need for tracheostomy. Am J Surg. 2014;207(5):664-9.
- Leder SB, Ross DA. Confirmation of No Causal Relationship Between Tracheotomy and Aspiration Status: A Direct Replication Study. Dysphagia. 2010;25(1):35-9.
- Brown CV, Hejl K, Mandaville AD, Chaney PE, Stevenson G, Smith C. Swallowing dysfunction after mechanical ventilation in trauma patients. Journal of Critical Care. 2011;26(1):108 e9-13.
- Shin JC, Yoo JH, Lee YS, Goo HR, Kim DH. Dysphagia in cervical spinal cord injury. Spinal Cord. 2011;49:1008-13.
- MacBean N, Ward E, Murdoch B, Cahill L, Solley M, Geraghty T, et al. Optimizing speech production in the ventilator-assisted individual following cervical spinal cord injury: a preliminary investigation. International Journal of Language & Communication Disorders. 2009;44(3):382-93.
