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Updated: Aug 18, 2026

Pupillary Response as Assessment of Effective Seizure Induction by Electroconvulsive Therapy
Published on: April 11, 2019
[Cranial imaging and serology tests are not helpful in tonic pupil. A retrospective study]
E Schnitzler1, F Reinhardt, B Tomandl
1Augenklinik mit Poliklinik, Friedrich-Alexander-Universität Erlangen-Nürnberg.
Background:
Tonic pupil (TP) is a common disorder of parasympathetic innervation. In contrast to textbook recommendations, cranial imaging is still being performed in most of the patients with TP. The intention of the present study is to show that cranial imaging is of no benefit.
Patients And Methods:
The medical records of 33 patients with TP were analyzed retrospectively. All patients had undergone a complete ophthalmological, orthoptic, and neurological investigation. Cranial imaging was performed by computed tomography or magnetic resonance imaging. Serology tests were carried out in some of the patients.
Results:
Diagnostic imaging provided no additional data revealing the underlying cause of TP.
Conclusions:
Cranial imaging in isolated tonic pupil is not helpful. Because of therapeutic implications, diagnostic evaluation can be recommended only in patients older than 50 years to exclude giant cell arteritis and syphilis.

