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Denise Louis-Bar (1914-1999)

Denise Louis-Bar (1914-1999)

Called “La rousse médicale” because of the color of her hair, Louis-Bar was a Belgian neuropsychiatrist who provided the eponymous description of ataxia-telangiectasia. 


Born in Belgium in 1914, Denise Bar lived in Spain with her parents during World War I. Her experiences during these years would influence the trajectory of her entire career. Upon returning to Belgium, she graduate from teh Free University of Brussels in 1939. She married F. Louis in 1939 and began to use the hyphenated name Louis-Bar.

With the onset of World War II, she trained under Ludo van Bogaert (1897-1989) at the Bunge Institute. There, she was instructed to study the case of a 9-year-old child with ataxia and telangiectasia “in detail”. This led to the 1941 Confinia Neurologia report where Louis-Bar described ataxia and developmental disability with distinct dermatologic findings. Louis-Bar posited that the syndrome represented a phakomatosis, or neuro-cutaneous syndrome.

Following Louis-Bar's report, further cases of ataxia-telangiectasia were presented at international conferences. Elena Boder (1908-1995) and Robert P. Sedgwick, two neurologists from California, described a series of cases, calling the disorder “ataxia-telangiectasia”. Boder and Sedgwick went on to publish many articles on this disorder, always urging the use of the descriptive rather than eponymous term “Louis-Bar syndrome.”

However, the terminology of Louis-Bar syndrome was used widely during the 1960s. During this time, the priority of description was disputed. Ladislav Syllaba (1986-1930) and Kamil Henner (1895-1967), a Czech team, claimed priority, with a description in 1926 in Revue Neurologique. The movement disorder described by Syllaba and Henner suggested an extrapyramidal disorder, rather than cerebellar ataxia - which may have led to this delay in recognition.

Louis-Bar was largely absent from the discussions on naming and priority of the syndrome. After a short yet productive academic career at the University of Liège, she moved to Brussels in 1957 when her husband was promoted. In Brussels, she focused on caring for children and adults with severe neurologic disabilities and founded or contributed to the foundation of a dozen centers that provided pediatric rehabilitation services and outpatient facilities in poor areas of Brussels.


Coon, E.A., P.J. Koehler, and C.J. Boes (2018), Denise Louis-Bar: The eponymous woman of Louis-Bar syndrome. Neurology, 2018. 91(4): p. 175-179.


Essay by Elizabeth Coon, MD and Alison Christy, MD, PhD

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