Seminars in neurology
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Distinguishing primary headache from secondary headache is the first objective of every new clinical encounter with a patient complaining of headache. The history is king in headache medicine-90% of patients presenting with headache have a primary headache disorder and the examination is normal. The history must be elicited because patients will not always volunteer seminal information. ⋯ The second objective, of course, is making the correct diagnosis of the primary headache disorder. Although at first glance this appears obvious and almost patronizing, making the correct diagnosis is often not a priority, nor is it a process that is emphasized in undergraduate and postgraduate training programs. Knowing some simple rules and standard questions will make the process almost fail proof.
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Myasthenia gravis is typically an acquired autoimmune disorder in which antibodies are directed at structural components of the neuromuscular junction, most commonly the nicotinic acetylcholine receptor. The clinical manifestations of skeletal muscle weakness are broad. Patients most often report fatigable muscle weakness. ⋯ Symptoms may be confined to the eyes (ocular myasthenia) or reflect bulbar, limb, or respiratory muscle weakness (generalized myasthenia). The diagnosis is based on a characteristic history and the finding of fatigable muscle weakness on examination, and may be supported by diagnostic tests such as finding elevated titers of acetylcholine receptor or muscle-specific receptor tyrosine kinase (MuSK) antibodies, a positive Tensilon test, a decremental response on slow repetitive nerve stimulation, and abnormal jitter on single fiber electromyography. This article presents a series of pearls to aid in the clinical and laboratory diagnosis of myasthenia gravis, emphasizing key historical features, common and characteristic findings on examination, and potential pitfalls in the use of ancillary diagnostic studies.