The term "ocular myasthenia gravis" describes a subtype of MG where muscle weakness is confined to the eyes, i.e. extraocular muscles, m. levator palpebrae superioris, and m. orbicularis oculi. Typically, this subtype evolves into generalized MG, usually after a few years. Eating
The weakness of the muscles involved in swallowing may lead to swallowing difficulty (dysphagia). Typically, this means that some food may be left in the mouth after an attempt to swallow, or food and liquids may regurgitate into the nose rather than go down the throat (velopharyngeal insufficiency). Weakness of the muscles that move the jaw (muscles of mastication) may cause difficulty chewing. In individuals with MG, chewing tends to become more tiring when chewing tough, fibrous foods. Difficulty in swallowing, chewing, and speaking is the first symptom in about one-sixth of individuals. Speaking
Weakness of the muscles involved in speaking may lead to dysarthria and hypophonia. Speech may be slow and slurred, or have a nasal quality. In some cases, a singing hobby or profession must be abandoned. Head and neck
Due to weakness of the muscles of facial expression and muscles of mastication, facial weakness may manifest as the inability to hold the mouth closed (the "hanging jaw sign") and as a snarling expression when attempting to smile. With drooping eyelids, facial weakness may make the individual appear sleepy or sad. Difficulty in holding the head upright may occur.
This is due to the right ventricular stress and ischemia that can occur in PE. Other symptoms are syncope and hemoptysis. DVT is a common cause. Thus, symptoms including leg pain, redness, and swelling can be present. The likelihood of pulmonary embolism can be evaluated through various criteria. The Wells score is often calculated. It gives points based on these symptoms and patient risk factors. Causes
Causes include any obstruction of blood flow to and from the heart. There are multiple, including pulmonary embolism, cardiac tamponade, and tension pneumothorax. Other causes include abdominal compartment syndrome, severe aortic valve stenosis, and disorders of the aorta. Constrictive pericarditis is a rare cause. Masses can grow to press on major blood vessels causing shock. Tension pneumothorax
A pneumothorax occurs when air collects in the pleural space around the lungs. Normally, this space has negative pressure to allow the lung to fill. Pressure increases as more air enters this space. The lung collapses, impairing normal breathing. Surrounding structures may also shift. When severe enough to cause these shifts and hypotension, it is called a tension pneumothorax. This is life-threatening. The veins supplying the heart are compressed. Thus, venous return is decreased. With the heart unable to fill, cardiac output drops. Hypotension and shock ensue. If not rapidly treated, it can lead to cardiac arrest and death. Pulmonary embolism
A pulmonary embolism (PE) is an obstruction of the pulmonary arteries. Deaths from PE have been estimated at ~100,000 per year in the United States. However, this may be higher in recent years.