A clinical and radiological investigation of paediatric dysphagia following traumatic brain injury

Morgan, Angela Tamsin (2003). A clinical and radiological investigation of paediatric dysphagia following traumatic brain injury PhD Thesis, School of Health and Rehabilitation Sciences, The University of Queensland.

       
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Author Morgan, Angela Tamsin
Thesis Title A clinical and radiological investigation of paediatric dysphagia following traumatic brain injury
School, Centre or Institute School of Health and Rehabilitation Sciences
Institution The University of Queensland
Publication date 2003
Thesis type PhD Thesis
Supervisor Prof Bruce Murdoch
Dr Elizabeth Ward
Total pages 326
Collection year 2003
Language eng
Subjects L
321025 Rehabilitation and Therapy - Hearing and Speech
730111 Hearing, vision, speech and their disorders
730303 Occupational, speech and physiotherapy
Formatted abstract The drive for rationing and efficiency in healthcare is gaining momentum, and is coupled with policy makers and managers pushing for evidence-based practice (Little, 2001; Mooney, 1997; Stoelwinder, 2001). Strong evidence, however, regarding effective paediatric healthcare strategies (for individuals or populations) is not available for a broad range of important issues (Gazarian, 2001). One paediatric area lacking in evidence in the field of speech pathology is traumatic brain injury. Brain injury has been reported to be the most challenging disorder faced by a rehabilitation team (Barnes & Ward, 2000). Whilst the medical impact of a brain injury is common between adults and children, the paediatric population may also experience unique issues that may impair the recovery process (McLean et al. 1995). Dysphagia, or swallowing impairment, is one common sequelae following traumatic brain injury (TBI) in children and adults (Logemann, Pepe & Mackay, 1994; Mackay, Morgan & Bernstein, 1999a,b; Rowe, 1999). Swallowing impairment in the adult population post-TBI has been recognised as a contributing factor to deleterious respiratory complications such as aspiration pneumonia (Langmore et al, 1998).

Despite recognition of the need for evidence-based practice, the common occurrence and potential impact of dysphagia on respiratory function post-TBI, and the potential differences between adults and children in regard to recovery post-TBI, there is a paucity of information documenting the nature of dysphagia in the paediatric population post-TBI. Therefore the present series of investigations aimed to document the prevalence, nature, course of recovery and functional outcomes associated with dysphagia in the paediatric population post-TBI. A series of seven investigations were conducted, and with the exception of the first large group retrospective investigation, the remaining six investigations involved participants from a group of 19 paediatric patients with persistent dysphagia subsequent to TBI.

The first investigation was a retrospective analysis that involved determining the incidence, characteristics and predictive factors for dysphagia associated with TBI in a total of 1145 children aged 0 to 16 years. Data collection involved medical chart review and the documentation of biographical and medical details. The incidence of dysphagia across all brain injury admissions was found to be 5.3%. A breakdown of incidence based on injury severity revealed incidence figures of 68% for severe TBI, 15% for moderate TBI, and only 1% for mild TBI. The participants were divided into two groups, one group with, and one group without dysphagia. Descriptive statistics and multiple analysis of variance calculations revealed significant differences between the two subgroups. Patients with dysphagia demonstrated a greater average length of hospitalisation, length of ventilation, duration of speech pathology intervention, duration of supplemental feeding, duration until initiation of oral intake (DIOF), duration to total oral intake (DTOF), and period of time from the initiation of oral intake until achievement of total oral intake (DI-TOF). A significant difference was also found between the two populations in relation to Glasgow Coma Scale (GCS) score and Computed Tomography (CT) classification. Patients with swallowing impairment presented with lower GCS scores on average, and also experienced a higher incidence of CT results indicative of poorer outcomes/dysphagia, including infracranial haematoma, diffuse axonal injury, and multifocal injury. Finally, investigation of predictive factors for dysphagia revealed that a GCS <8.5, and a ventilation period in excess of 1.5 days were the strongest indicators for dysphagia being present. The findings of this investigation were discussed with reference to their value in assisting clinicians in predicting patients who are at risk for dysphagia, for prioritising patients, and for planning service delivery to facilitate effective and timely medical and speech pathology intervention.

The second investigation examined the acute clinical characteristics of swallowing impairment in 14 participants aged four years one month to 15 years. Specifically, this investigation aimed to provide a detailed clinical examination of the acute features of cognitive status, nutritive and non-nutritive oral motor function, feeding function, dietary recommendations based on clinical data, and an indication of overall feeding severity. Participants were examined using a range of perceptual assessments including the Ranchos Los Amigos (RLA) cognitive scale, the Verbal Motor Production Assessment for Children (VMPAC), the Frenchay Dysarthria Assessment (FDA), the Schedule for Oral Motor Assessment (SOMA), the Parramatta Hospitals' Assessment of Dysphagia (PHAD), and an informal feeding trial.

The results of the clinical assessment of swallowing in the paediatric patients in the acute phase post-TBI revealed a pattern of impaired cognition, altered behaviour relating to feeding, severe tonal and postural deficits, oral motor, respiratory and laryngeal impairments, and oral sensitivity issues in the majority of the 14 cases. These findings demonstrated that the severe swallowing impairment in the paediatric population post-TBI is impacted upon by multi-level deficits involving more than the specific components of the swallowing mechanism. In light of the identification of deficits unable to be observed on videofluoroscopic investigation alone, such as impaired cognition and reduced jaw stability, the outcomes of this investigation are discussed in relation to the importance of the clinical evaluation for identifying intervention targets for the paediatric patient post-TBI.

The third investigation examined the acute radiological characteristics present in a group of 18 participants with TBI, aged 11 months to 15 years. The participants were examined using a videofluoroscopic swallowing study (VFSS) following clinical signs indicative of severe swallowing dysfunction. Three consistencies were trialled for the purpose of this study, including liquid barium, barium paste, and a piece of sandwich or 'soft chewable' consistency. Analysis of the VFSS procedure involved rating the oral preparatory, oral and pharyngeal phases of the swallow, calculating an Oropharyngeal Swallowing Efficiency score (OPSE), documenting the underlying physiological deficits, and determining a rating on the Dysphagia Outcome and Severity Scale (DOSS).

Findings of the third investigation supported preliminary research by Rowe (1999), indicating that the number of swallowing deficits in children following TBI are consistent with a pattern of oropharyngeal impairments. More specifically, observable features or physiological impairments which were identified as prominent in the present patient group included: reduced lingual control, hesitancy of tongue movement, repetitive tongue pumping, the presence of aspiration (including silent aspiration), delayed swallow reflex trigger, reduced laryngeal elevation and closure, and reduced peristalsis. Specific differences were noted in the current paediatric population when compared to existing literature on the adult TBI patients in regard to both observable characteristics, and the physiological impairment/s underlying these features, including: lack of anterior containment of the bolus during lingual hesitancy, multiple locations of aspiration during the swallowing sequence, the absence of laryngeal spasm, and the absence of cricopharyngeal disorders. These outcomes were discussed with respect to aiding clinicians understanding of the admitting characteristics and acute presentation of the paediatric population with dysphagia post-TBI, for facilitating planning of therapeutic management.

The fourth investigation involved establishing the resolution of swallowing impairment, and functional outcomes for swallowing in 13 participants aged four years one month to 15 years. The clinical evaluations conducted were identical to those outlined for the second investigation. However, the fourth investigation required that participants were assessed twice each week subsequent to the initial assessment, and that they were then subsequently assessed throughout their rehabilitation stay up to the point of resolution of dysphagia and the return to a normal diet. This investigation established that the resolution of oral motor impairment, swallowing impairment and return to oral intake was achieved in less than 11 weeks post-referral for all 13 participants. This finding suggested a positive prognosis for the return to functional feeding skills and a normal oral diet, in addition to indicating a need for continual monitoring and intervention for at least a three month period post-injury. Three main phases of rehabilitation were noted within the three month period: a) Acute Phase (weeks 0-2); b) Rapid recovery phase (weeks 3-7); and c) Plateaued recovery phase (weeks 8-11). The greatest amount of change occurred in the acute phase and during the first two weeks of the rapid recovery phase, indicating a greater demand for monitoring and thus clinical services at this time. The rapid recovery phase largely signalled a move to a full oral diet, with the nasogastric tube being removed, in addition to a marked improvement in cognition. Improvements in cognition signalled increased effectiveness for employing therapeutic strategies at this stage, with the patient having greater awareness of their dysphagia and an increased ability to follow instructions. Finally, the plateaued recovery phase signalled that patients were largely independent for feeding, having regained functional feeding skills, however persistent deficits remained that required ongoing rehabilitation.

Analysis of the relationship between cognition and the return to oral intake indicated that participants commenced oral intake at level III or IV during the acute phase, achieved full oral feeding at RLA levels IV-VI, and achieved a normal oral diet at RLA levels VI-VIII during the pleateaued recovery phase. Data in the present study also revealed a pattern of parallel resolution for the variables of cognition, oral motor impairment and swallowing function, indicating the need to monitor all three aspects during the clinical bedside evaluation (CBE) for the paediatric population with dysphagia post-TBI. The findings of this investigation were discussed in relation to providing baseline data for clinicians to compare the prognosis and progress of their paediatric patient's post-TBI with similar symptomatology to the present group data. Furthermore, the outcomes were discussed in their ability to facilitate more realistic goal setting, resulting in optimal rehabilitation programming and potentially improved dysphagia outcomes.

With the natural clinical course and recovery of participants post-TBI established, the fifth investigation aimed to determine the underlying physiological basis for the presenting swallowing deficits in a group of seven participants aged 11 months to 13 years three months. The exact radiological procedure and videofluoroscopic data analysis used in the fifth investigation was identical to that in the third investigation, with the addition of analysis involving the Penetration-Aspiration Scale in the fifth investigation. All seven participants in the fifth investigation presented clinically with safe and functional swallowing at six months post-TBI, however, VFSS revealed a number of residual deficits including persistent physiological impairments, and reduced swallowing efficiency. In light of mildly reduced cognitive functioning, and the limitations of the VFSS to account for normal mealtime volumes and the effects of fatigue, the data suggested a continued risk of occasional aspiration in the participants. The data was discussed in regard to the potential clinical implications of long-term residual physiological deficits of the swallowing mechanism.

Whilst the fourth and fifth investigations outlined the clinical and radiological resolution and outcomes for dysphagia post-TBI, the participants in these investigations presented with injuries largely focused in the cortical region of the brain. In contrast the involvement of brainstem injury is recognised as being associated with more serious persistent dysphagia deficits. The sixth investigation detailed the clinical and radiological resolution and outcome of a 14-year-old paediatric patient, B.A., with dysphagia subsequent to brainstem injury. Neurological examination revealed severe bulbar dysfunction, with an inability to voice or swallow.

B.A. was assessed using clinical, radiological and endoscopic assessments of dysphagia. The initial clinical evaluation was conducted 15 days post-injury when B.A. was medically stable as determined by the medical officer in charge. A clinical examination of swallowing was then subsequently conducted twice a week up until B.A. was discharged. Following discharge, B.A. was assessed on a weekly basis as an outpatient up until the second VFSS was conducted. For the purposes of this investigation, only the results of the first clinical assessment per week were reported. The initial VFSS assessment was conducted at 70 days (2 months, 10 days) post-injury. The follow-up VFSS was conducted approximately 8 months later, or approximately 10 months (297 days) post-injury. Endoscopic Evaluation of Swallowing (EES) was conducted 13 days following the initial VFSS assessment (83 days post-injury) in order to investigate laryngeal function subsequent to the presence of aspiration during the swallow on the first VFSS.

The present study provided data on the pattern of clinical and radiological resolution of a severe swallowing impairment in a paediatric case post-brainstem injury. Clinically this case presented with a pattern of severe oral motor and oropharyngeal swallowing impairment post-injury which resolved relatively rapidly for the initial 12 weeks post-injury. Recovery then slowed to gradual progress for weeks 12-20, with overall resolution plateauing at approximately 20 weeks post-injury. At this time B.A.'s oral motor and swallowing skills largely resolved to only a mild clinical impairment level, and her skills remained consistently at this level up until 10 months post-injury. However, B.A. remained on supplemental feeding for the duration of the 10-month follow-up period given her poor initial radiological profile, which included silent aspiration of thin fluids, and issues of inefficiency. She had only achieved pureed intake under supervision up until the follow-up VFSS at 10 months post-injury at which point she was no longer aspirating, and was placed on a semi-sohd diet with fluid intake continuing via supplemental feeding (PEG). Overall the pattern of swallowing impairment observed in the present case is consistent with the severe nature of dysphagia post brainstem injury reported by Rowe (1999). The clinical resolution however, was considerably longer in the present case study, highlighting the significant long-term persistent swallowing deficits, which can be associated with brain stem injury. These findings were discussed in relation to the poorer prognosis for the return to oral feeding and apparent lack of cognitive-behavioural factors influencing dysphagia in a subject with brainstem injury when compared to those participants with cerebrally based neuropathology. Furthermore, the findings were discussed in relation to the long-term prognosis and ongoing aspiration risk for patients with brainstem injury.

The series of investigations in the present thesis served to document the incidence, clinical and radiological acute swallowing deficits, and the clinical and radiological resolution and outcomes of swallowing impairment following TBI in the paediatric population. These investigations highlighted the benefits of evidence-based practice with the provision of this baseline data assisting clinicians in relation to diagnosis, prognosis, prioritisation, and in assisting service delivery planning. The final investigation also revealed the apparent long-term nature of dysphagia post severe brainstem injury, calling for further research in this area. Considering the prevalence figures for dysphagia in the population with moderate and severe TBI, a main direction for future research would be to more clearly delineate which factors are predictive of dysphagia in this patient population. In addition, the identification of residual deficits highlights another area for future research would be larger prospective investigations examining the long term impact of these persistent deficits in regard to complications, such as impaired respiratory function, to determine the true impact of dysphagia on the paediatric population post-TBI.
Keyword Deglutition disorders in children
Brain-damaged children

 
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Created: Fri, 24 Aug 2007, 18:07:45 EST