Clinically probable brainstem stroke presenting primarily as dysphagia and nonvisualized by MRI

The Trouble with Swallowing: Dysphagia as the Presenting Symptom in Lateral Medullary Syndrome

BACKGROUND

Posterior circulation strokes account for approximately one-fourth of all ischemic strokes, but are frequently misdiagnosed by emergency providers. Current standard stroke screening tools such as the National Institutes of Health Stroke Scale and the Cincinnati Prehospital Stroke Scale are weighted toward anterior circulation stroke diagnosis. Lateral medullary syndrome, a type of posterior circulation stroke, can be particularly challenging to diagnose due to nonspecific presenting symptoms, such as dysphagia.

CASE REPORT

This report describes a 65-year-old man who presented with dysphagia, dizziness, and hoarseness. An initial neurological examination did not reveal any gross deficits, and imaging to evaluate for posterior circulation stroke was not obtained. The patient presented the following day with worsening symptoms, prompting imaging that revealed a large cerebellar ischemic infarction. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Although dysphagia frequently occurs in lateral medullary syndrome, it is rarely the presenting symptom in the emergency department. In patients with cerebrovascular risk factors who present with dysphagia, a complete neurological examination should be performed and noncontrast computed tomography (CT) of the head should be obtained if a neurological deficit is appreciated. Due to their poor sensitivity, CT scans can frequently miss posterior circulation strokes, therefore magnetic resonance imaging should be considered if provider suspicion remains high. Emergency providers are encouraged to have a high level of suspicion for this rare but debilitating stroke syndrome to avoid misdiagnosis and delayed care.

Bilateral Ageusia and Tongue Anesthesia Following Unilateral Brainstem Infarct: A Case Report with a Brief Review of the Literature

We present the case of a 63-year-old male patient who suffered bilateral ageusia following a unilateral left-sided mesencephalon infarct. To the best of our knowledge, this is the first description of a mesencephalon lesion leading to ageusia. We discuss the literature on this rare but important symptom following a stroke.

Diagnostic evaluation of dysphagia

Taking a careful history is vital for the evaluation of dysphagia. The history will yield the likely underlying pathophysiologic process and anatomic site of the problem in most patients, and is crucial for determining whether subsequently detected radiographic or endoscopic 'anomalies' are relevant or incidental. Although the symptoms of pharyngeal dysphagia can be multiple and varied, the typical features of neurogenic pharyngeal dysphagia are highly specific, and can accurately distinguish pharyngeal from esophageal disorders. The history will also dictate whether the next diagnostic procedure should be endoscopy, a barium swallow or esophageal manometry. In some difficult cases, all three diagnostic techniques may need to be performed to establish an accurate diagnosis. Stroke is the most common cause of pharyngeal dysphagia. A videoradiographic swallow study is vital in such cases to determine the extent and timing of aspiration and the severity and mechanics of dysfunction as a prelude to therapy.

A case study of the resolution of paediatric dysphagia following brainstem injury: clinical and instrumental assessment

The coexistance of a swallowing impairment can severely impact upon the medical condition and recovery of a child with traumatic brain injury [ref.: Journal of Head Trauma Rehabilitation 9 (1) (1994) 43]. Limited data exist on the progression or outcome of dysphagia in the paediatric population with brainstem injury. The present prospective study documents the resolution of dysphagia in a 14-year-old female post-brainstem injury using clinical, radiological and endoscopic evaluations of swallowing. The subject presented with a pattern of severe oral-motor and oropharyngeal swallowing impairment post-injury that resolved rapidly for the initial 12 weeks, slowed to gradual progress for weeks 12-20, and then plateaued at 20 weeks post-injury. Whilst a clinically functional swallow was present at 10 months post-injury, radiological examination revealed a number of residual physiological impairments, reduced swallowing efficiency, and reduced independence for feeding, indicating a potential increased risk for aspiration. The data highlight the need for early and continued evaluation and intensive treatment programs, to focus on the underlying physiological swallowing impairment post-brainstem injury, and to help offset any potential deleterious effects of aspiration that may affect patient recovery, such as pneumonia.

Predictors of prolonged dysphagia following acute stroke

Dysphagia following acute stroke frequently necessitates prolonged enteral feeding. There is evidence that early enteral feeding via percutaneous endoscopic gastrostomy (PEG) is both beneficial and safe. The aim of this study was to identify predictors of prolonged dysphagia. The subjects were 149 consecutive patients admitted with acute stroke. Clinical findings and imaging results were prospectively collected, and subsequent progress recorded. Subjects were divided into 3 groups for analysis: no dysphagia; transient dysphagia (< or =14 days); or prolonged dysphagia (>14 days). Validity of the water swallow test as a predictor of aspiration pneumonia was confirmed. Significant associations for prolonged dysphagia were seen with stroke severity, dysphasia and lesions of the frontal and insular cortex on brain imaging. These results indicate that it may be possible to predict patients who will develop prolonged significant dysphagia following acute stroke thereby facilitating referral for insertion of PEG at an earlier time point.

Swallowing disorders

Swallowing disorders affect a large and growing number of people in the United States, particularly the elderly. An appreciation of the anatomy, physiology and pathophysiology of swallowing disorders allows the practitioner to assess these problems and to make arrangements for their treatment. The purpose of this article, therefore, is to give an overview of the diagnosis and treatment of swallowing disorders.

Oropharyngeal dysphagia due to iatrogenic neurological dysfunction

Oropharyngeal dysphagia due to iatrogenic neurological dysfunction may relate to either medication side effects or surgical complications. There are several general mechanisms by which neurological side effects of medications can cause or aggravate oropharyngeal dysphagia. These include decreased level of arousal, direct suppression of brainstem swallowing regulation, movement disorders (dyskinesias, dystonias, and parkinsonism), neuromuscular junction blockade, myopathy, oropharyngeal sensory impairment, and disturbance of salivation. Postsurgical oropharyngeal dysphagia due to neurological dysfunction has been described in association with carotid endarterectomy, esophageal cancer surgery, anterior cervical fusion, and ventral rhizotomy for spasmodic torticollis. A potential explanation for oropharyngeal dysphagia following these surgical procedures is intraoperative mechanical disruption of the innervation of the pharyngeal constrictor muscles by the pharyngeal plexus. Posterior fossa and skull base surgery can lead to dysphagia as a result of intraoperative damage to brainstem centers and/or cranial nerves involved in swallowing. Perioperative stroke is the most likely explanation for oropharyngeal dysphagia appearing acutely following surgery, especially if the type of surgery predisposes to embolism or hypoperfusion.

Neurogenic dysphagia: what is the cause when the cause is not obvious?

The potential causes of neurogenic oropharyngeal dysphagia in cases in which the underlying neurologic disorder is not readily apparent are discussed. The most common basis for unexplained neurogenic dysphagia may be cerebrovascular disease in the form of either confluent periventricular infarcts or small, discrete brainstem stroke, which may be invisible by magnetic resonance imaging. The diagnosis of occult stroke causing pharyngeal dysphagia should not be overlooked, because this diagnosis carries important treatment implications. Motor neuron disease producing bulbar palsy, pseudobulbar palsy, or a combination of the two can present as gradually progressive dysphagia and dysarthria with little if any limb involvement. Myopathies, especially polymyositis, and myasthenia gravis are potentially treatable disorders that must be considered. A variety of medications may cause or exacerbate neurogenic dysphagia. Psychiatric disorders can masquerade as swallowing apraxia. The basis for unexplained neurogenic dysphagia can best be elucidated by methodical evaluation including careful history, neurologic examination, videofluoroscopy of swallowing, blood studies (CBC, chemistry panel, creatine kinase, B12, thyroid screening, and anti-acetylcholine receptor antibodies), electromyography, and magnetic resonance imaging (MRI) of the brain, plus additional procedures such as lumbar puncture and muscle biopsy as indicated. Little is known about aging and neurogenic dysphagia, specifically the relative contributions of natural age-related changes in the oropharynx and of diseases of the elderly, including periventricular MRI abnormalities, in producing dysphagia symptoms and videofluoroscopic abnormalities in this population.