gms | German Medical Science

Objective: In Germany of the thirties, the posttraumatic anisocoria was mostly seen as a lesion of the sympathetic nerve system. The English literature presented the uncal herniation with direct injury of the oculomotor nerve in the same decade. The background of a major experimental work from a German lab is analysed.

The study of Schörcher (1936, Zentralblatt für Chirurgie) was a result of the criticism to the work of Hoessley, who by experiments reported a unilateral dilated pupil as a result of “local intracranial pressure”. Schörcher developed a contrary hypothesis. The work was a product of the experimental laboratories at the university in Munich, founded by Sauerbruch.

Methods: In a complex experiment in dogs, the range of pupils under normal tension conditions and after induced hypertension was analysed. The sympathetic nerves and the oculomotor nerve had been disconnected, isolated and dissected. The induction of increased intracranial pressure was represented by administration of a mix of oil and zinc paste into the intracranial extra-cerebral space. The sympathetic trunk was disconnected beneath the Ggl. cervicale sup. The disconnection of the oculomotor nerve was performed after a temporal craniotomy.

Results: The historical results: An epidural or subdural haematoma is able to cause an ipsilateral dilated pupil by central irritation of the sympathetic nerves. The meaning of the disconnected oculomotor nerve for the unilateral dilated pupil after an ipsilateral haematoma should be rated as low. The theory of a peripheral injured oculomotor nerve as major cause for a unilateral dilated pupil after ipsilateral haematoma has been rejected.

Conclusion: The technical imponderables were too great for his time. Nevertheless, the study gained positive resonance in German literature. The work was lauded as a greater advance in the understanding of the sympathetic nerve system. The reworking shows once more the fundamental impact of patients’ observation as a scientific method. Results gained by animal experiments can lead to confusing results. There are increasing publications emphasising that this recognition has a special meaning in neuro-traumatological topics. This historical work warns the neuro-traumatologically working physician in interpretation of animal experiments that promise progress.