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[A case of visual allesthesia].
1Department of Neurosurgery, Tokyo Jikei University School of Medicine, Japan.
No to Shinkei = Brain and Nerve
|November 1, 1991
Summary
A patient developed visual allesthesia, experiencing illusory object transpositions into his defective visual field after surgery for a brain arteriovenous malformation. This rare phenomenon may stem from irritation in the affected brain regions post-seizure.
Area of Science:
- Neuroscience
- Ophthalmology
- Neurology
Background:
- A thirty-year-old male underwent surgery for a right temporo-occipital arteriovenous malformation.
- Postoperatively, the patient developed left homonymous hemianopsia, a visual field defect.
Observation:
- Six months post-surgery, the patient experienced generalized convulsions followed by visual allesthesia.
- He reported illusory leftward transpositions of objects viewed in his right visual field, into the defective area.
- These palinoptic illusions persisted for minutes, causing monocular diplopia.
Findings:
- Magnetic Resonance Imaging (MRI) revealed extensive postoperative changes in the right temporal, occipital, and parietal lobes.
- The lesion impacted the right fusiform and lingual gyri, as well as the right lateral geniculate body and posterior thalamus.
- The visual allesthesia episodes coincided with seizure activity.
Implications:
- The findings suggest visual allesthesia may arise from irritation of surgically altered brain regions, particularly following seizures.
- This case highlights a rare visual disturbance linked to specific neuroanatomical damage and subsequent neurological events.
- Further research into the neural mechanisms underlying visual allesthesia is warranted.