Pupillary constriction on stimulation of the parietal cortex-A novel finding

Area of Science:

• Neuroscience
• Epileptology
• Clinical Neurology

Background:

• Pupillary changes are key indicators in focal epilepsy diagnosis.
• While subcortical pupillomotor networks are known, cortical origins of pupillary control remain unclear.

Observation:

• A case of drug-resistant focal epilepsy presented with pupillary constriction during seizures.
• Stereoelectroencephalography (SEEG) identified seizure onset in the posterior right intraparietal sulcus.

Findings:

• Direct cortical electrical stimulation of the intraparietal sulcus reproduced the patient's habitual seizures and pupillary constriction.
• This study provides the first SEEG evidence of ictal pupillary constriction with confirmed cortical localization.

Implications:

• The posterior intraparietal sulcus is identified as a potential cortical generator of pupillary constriction.
• This localization may improve surgical planning for patients with drug-resistant focal epilepsy and pupillary symptoms.