Bell's Palsy and Its Semantic Change over Time

From 1821 to 1829, Sir Charles Bell presented cases of facial paralysis from infection, trauma, and unknown causes. As such, "Bell's palsy" initially referred to facial palsy of any etiology. Today, the term is reserved for idiopathic peripheral facial palsy. The objectives of this analysis were to establish when the eponym came to vogue and delineate the semantic shift from its original definition to its current one.

Extensive review of available 19th and 20th century literature mentioning "Bell's palsy" and "Bell's paralysis."

Historical accounts have eponymously attached Bell's name to facial paralysis as early as the 1840s-Bell's palsy was first used to describe cases of facial palsy of any cause. In 1886, Gowers characterized Bell's palsy as a "neuritis usually within the Fallopian Canal," distinguishing it as a separate etiology. Over the next decades, the definition narrowed to peripheral facial paralysis from cold exposure or unknown causes. By the 1940s, its natural history was well described-an acute, unilateral, idiopathic, and usually self-limited peripheral facial palsy.

The semantic change of a word over time can tell us a remarkable story of its history and origins. Absence of a discrete lesion, lack of proven treatment, and good prognosis without intervention distinguished Bell's palsy from other causes of facial paralysis. Over time, the definition has narrowed from a facial palsy of any cause to an idiopathic peripheral facial palsy. Recent evidence supporting Bell's palsy as a viral mononeuritis may have driven its recent semantic change toward this specific etiology.