Sir Gordon Morgan Holmes (1876–1965): one of the founders of modern neurology

Sir Gordon Morgan Holmes (1876–1965) was one of the most important founders of modern neurology and a great teacher and scientist. He was the first scientist to challenge the theory of the unitary function of the cerebellum and described cerebellar disorders. Holmes together with Thomas Grainger Stewart (1877–1957) described 40 cases of the rebound phenomenon in cerebellar disease (Stewart-Holmes maneuver or Stewart-Holmes test). He also described the symptoms of inherited neurodegenerative spinocerebellar ataxia involving the olivary nucleus (Gordon-Holmes syndrome). Independently from the Australian neurologist William John Adie (1886–1935), he described the partial iridoplegia (Holmes-Adie pupil or Holmes-Adie syndrome). His teaching skills became clearly visible in Goulstonian and Croonian lectures dedicated to spinal cord injuries.

Introduction 2016 marks the 140th anniversary of the birth of an Irish neurologist Sir Gordon Morgan Holmes (1876-1965) ( Fig. 1) who through his research on the cerebellum and the visual cortex made a significant contribution to the development of neurology. He is also considered one of the most important founders of modern neurology and a great teacher and scientist [1,2]. Nowadays, neurologists use eponyms such as Gordon-Holmes syndrome and Holmes-Adie syndrome in symptomatologic descriptions. What is more, the Stewart-Holmes test is still an important part of neurological diagnostics.

Biographical sketch
Holmes was born on January 22, 1876, in Dillon House, Castlebellingham (County Louth, Ireland) 40 miles north of Dublin. He had three brothers and three sisters. His father Gordon Holmes was a farmer from the Louth County. Holmes' choice of a medical career was probably influenced by his mother's Kathleen's passing away when he was just a child [2,3]. The first stage of his education was at the Dundalk Educational Institute where despite his struggle with dyslexia, he was an excellent pupil [3]. He graduated from his medical studies at Trinity College in Dublin in 1897, obtaining a B.A., Senior Moderator in Natural Science degree. In the beginning of his career, he worked as a ship's surgeon on a ship sailing to New Zealand. After returning from the Antipodes a year later, thanks to the Stewart Scholarship in Nervous and Mental Diseases from Trinity College, he was able to participate in a foreign scientific internship at the Senckenberg Institute in Frankfurt-am-Main (Germany) [2,3]. He gained his knowledge in comparative anatomy and histology of the nervous

Holmes' scientific achievements
Prior to the outbreak of the WWI Holmes, together with Henry Head (1861-1940) worked on the identification of visual pathways [4]. He was a careful researcher who during the WWI made numerous observations on the dysfunctions of the cerebellum, spinal cord, and visual impairments among patients with gunshot wounds [5]. It should be underlined that the development of military technology during the WWI indirectly contributed to the advancement of knowledge about pathophysiology of the occipital cortex and the visual pathways. The bullets fired from rifles with low caliber but high kinetic energy relatively easily penetrated the skull without making cavitation or shock waves in the brain and neither the US marine Borps Doughboy helmet nor the British BBrodie^helmets were good protection for the occipital part of the soldiers' heads [6,7]. Skull fractures and occipital cortex damage were quite frequent on the WWI battlefields due to gunshot wounds. Therefore, Holmes as well as other physicians had numerous opportunities to conduct observations and analyzes, which in turn significantly contributed to the progress of understanding of the visual pathways [5][6][7]. Holmes in collaboration with the Ophthalmic Surgeon Consulting William Lister (1868-1944) performed perimetry on over 400 wounded soldiers. He mapped the line trajectory of gunshot wounds using X-rays and cross-sectional models of skull and brain [7]. He included his observations in among others the Goulstonian Lectures [8]. In 1918, Holmes described six cases of a visual disorientation with optic ataxia and bilateral posterior parietal cortex lesions which were due to perforating gunshot injuries of the head (Bálint-Holmes syndrome) [9]. He was also the first scientist to challenge the theory of the unitary function of the cerebellum and described cerebellar disorders through the following symptoms ataxia, asthenia, adiadochokinesia, and rebound [10]. Holmes together with Thomas Grainger Stewart (1877-1957) [1] described and explained 40 cases of the rebound phenomenon in cerebellar disease (Stewart-Holmes maneuver or Stewart-Holmes test) [11]. Holmes also described the symptoms of inherited neurodegenerative spinocerebellar ataxia involving the olivary nucleus (Gordon-Holmes syndrome). In 1931, independently from the Australian neurologist William John Adie , with whom he worked during his stay in France, he described the partial iridoplegia (Holmes-Adie pupil or Holmes-Adie syndrome) [12].

Holmes' impact on contemporary neurology
It is worth to underline that Holmes' achievements in mapping the visual pathways have had a decisive impact on the progress of neurological knowledge although many other researchers including Pierre Marie (1853-1940), Walthur Poppelreuter (1886-1939), George Riddoch (1888-1947), or Sir Charles Symonds (1890-1978) conducted similar research in this field [6,7]. Holmes accurately identified the main features of the retinal projection on the cortex. The method of testing the visual pathways used by Holmes in the WWI was also applied during similar research conducted in wounded soldiers of the WWII [6]. Holmes also contributed to the increase of knowledge of cerebellar disorders. The Stewart-Holmes test permanently entered the arsenal of neurological disorders diagnostic methods. Essential for modern neurological diagnostics is the Holmes-Adie syndrome, which is differentiated from the generalized neuropathy [13]. What is more, recent research suggests a genetic predisposition of the Gordon-Holmes syndrome [14].
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