Approach to dysarthria or dysphagia: Clinical sciences

Dysphagia, or impaired swallowing; and dysarthria, or impaired motor speech; are symptoms that can occur due to various neurologic- and non-neurologic conditions. Some important neurologic causes include cranial nerve dysfunction, neuromuscular junction disorders, neurodegenerative conditions, demyelination, and stroke.

Now, if a patient presents with chief concerns suggestive of dysphagia or dysarthria, you should obtain a focused history and physical examination. First, let's focus on dysphagia, which is difficulty swallowing. In this case, history might also reveal choking, coughing, or pain during swallowing. On examination, you will also notice signs of impaired swallowing, such as difficulty clearing the mouth of food and water, and coughing with, or shortly after, swallowing.

These findings are suggestive of dysphagia, so your next step is to determine the type of dysphagia, more specifically, whether the patient is presenting with oropharyngeal or esophageal dysphagia.

But, before we proceed, let’s quickly review the mechanics of swallowing, which includes oral, pharyngeal, and esophageal phases. The oral phase is voluntary and includes mastication, bolus preparation and moving the bolus into the pharynx. The pharyngeal phase consists of propelling the bolus through the pharynx and the upper esophageal sphincter. During this phase, the epiglottis closes over the larynx to protect the airway. Finally, the esophageal phase includes peristalsis of the esophagus until the bolus passes through the lower esophageal sphincter into the stomach.

The oral cavity, pharynx, upper esophageal sphincter, and upper part of the esophagus have striated muscles innervated by cranial nerves, while the lower esophagus and lower esophageal sphincter have smooth muscles innervated by the esophageal myenteric plexus.

Now, first, let’s focus on oropharyngeal dysphagia, which is associated with difficulty initiating swallowing and clearing food and liquids from the mouth. Sometimes, your patient might also report drooling. If food or liquids end up in the airway, your patient might even experience choking and coughing. Also, food and liquids might get out of the nose, known as nasal regurgitation. On the physical exam, you will see food or liquids left in the mouth after an attempt to swallow. You might also visualize a structural abnormality in the mouth or pharynx, which can range from poor dentition to a mass lesion. These findings suggest oropharyngeal dysphagia, so your next step is to assess the neurologic exam.

If the neurologic exam is normal, consider structural oropharyngeal dysphagia, so be sure to obtain a nasal endoscopy to directly visualize the oropharynx and larynx. If the endoscopy reveals a structural abnormality, diagnose structural oropharyngeal dysphagia. Possible causes include changes from prior head and neck surgery, radiation therapy, malignancy, and Zenker diverticulum.

On the other hand, if the neurologic exam reveals abnormalities, such as facial weakness, asymmetric palate elevation, tongue deviation, and signs of Parkinsonism, consider propulsive oropharyngeal dysphagia. Next, obtain video fluoroscopy, which is also known as a modified barium swallow. This diagnostic method uses X-rays to evaluate swallowing mechanics after the patient ingests different consistencies of barium-containing fluids and solids. If the video fluoroscopy reveals dysfunction without a structural lesion, possibly with signs of aspiration, diagnose propulsive oropharyngeal dysphagia. However, keep in mind that propulsive oropharyngeal dysphagia can also occur due to non-neurologic causes, including connective tissue disorders and sarcoidosis.

Now, let’s go back and take a look at esophageal dysphagia, which is associated with the sensation of food and liquids getting stuck in the neck or chest. The patient might also report chest pain or a medical history of gastroesophageal reflux disease, neck radiation, esophageal surgery, or medication-induced esophagitis. In some cases, they might have a systemic medical condition, such as scleroderma, which can cause decreased or absent esophageal peristalsis; and immunosuppression, such as from HIV, which can result in infectious esophagitis. On physical exam, you might find skin changes, such as from scleroderma or another mucocutaneous disorder.

These findings should point you towards esophageal dysphagia, so, you need to obtain an esophagogastroduodenoscopy, or an EGD, to figure out the underlying cause. Also, if you have concerns for esophageal motility conditions, be sure to obtain esophageal manometry.

If the EGD shows an obstructing lesion or inflammatory changes, diagnose structural esophageal dysphagia. This could be due to conditions like a Schatzki ring, peptic stricture, malignancy; or inflammation from medications and infections.

On the flip side, if there are no obstructing lesions or inflammatory changes on EGD, manometry shows abnormal esophageal pressures, diagnose propulsive esophageal dysphagia. Most commonly, this could be from impaired peristalsis or dysfunction of the lower esophageal sphincter. In this case, you should think of achalasia, scleroderma, and esophageal spasms.

Now, here’s a clinical pearl to keep in mind! The patient’s history can give you clues as to whether they have structural or propulsive esophageal dysphagia. Patients with structural esophageal dysphagia will typically report intermittent dysphagia to solids, while those with propulsive esophageal dysphagia will report persistent difficulties with both liquids and solids.