Classical brain stem syndrome. Definitions and history
Background: Inaccurate definitions of brain stem syndromes in the literature.
Methods: The original publications of the authors during the last century and the early years of this one were studied in relation to the neuro-ophthalmological diagnosis and neuroanatomy. It is the goal of this medico-historical investigation to compare the knowledge available at this time when the first descriptions were made with the clinical experience and understanding of today.
Results: The following classical brain stem syndromes are important for an ophthalmologist: diseases with III-paresis: Weber's syndrome (1863, ipsilateral oculomotor paralysis with alternating hemiplegia), Benedikt's syndrome (1889, oculomotor paralysis and crossed hemiparesis with tremor), Nothnagel Claude's syndrome (III-Paresis with alternating ataxia); diseases with VII-paresis: Millard Gubler's syndrome (1856, nuclear 7th nerve palsy with crossed hemiparesis), Foville's syndrome (1858, conjugate lateral gaze paralysis, ipsilateral nuclear palsy of the 7th nerve, crossed hemiparesis); diseases with VI-paresis: Raymond Cestan's syndrome (1895, abducent nerve paralysis with contralateral hemiparesis). Brain stem lesions are also found in Wallenberg's syndrome (1895, Horner's syndrome, absent corneal reflex, lateropulsion of saccadic eye movements, nystagmus, ataxia, dysphagia, hoarseness, sensory loss over the facial region, contralateral dissociated diminished sensibility (hemiparesis), etc.). The following two syndromes do not belong to the above-mentioned classical examples, because lesions of the long tracts of the brain stem are absent. However, since these two syndromes are accompanied by both ocular and neurological signs which indicate typical lesions of the brain stem, they are also mentioned here: Parinaud's syndrome (1883, paralysis of conjugate vertical gaze and paresis of convergence together with additional neuro-ophthalmological signs) and the Koerber Salus Elschnig's syndrome (1903, 1910, 1913, nystagmus retractorius, vertical gaze palsy, pupillary disturbances, and signs of midbrain disease).
Conclusions: The first descriptions of these syndromes, together with the figures illustrating the neuroanatomical findings in these lesions, are helpful for assessing the clinical picture. Some named syndromes which are used today in clinical diagnosis (e.g. Parinaud's syndrome) do not exactly correspond to the first descriptions in the last century.