# Transient binocular vision loss and pain insensitivity in Klippel–Feil syndrome: a case report

## TL;DR

A 12-year-old girl with Klippel–Feil syndrome experienced temporary vision loss and pain insensitivity, which improved with calcium and vitamin D treatment.

## Contribution

This case report presents a rare combination of transient vision loss and pain insensitivity in Klippel–Feil syndrome.

## Key findings

- Bilateral visual loss and optic disc swelling improved after calcium and vitamin D supplementation.
- The patient exhibited generalized hypoalgesia, likely due to congenital insensitivity to pain.
- Hypocalcemia was linked to low vitamin D levels, possibly from burn scarring.

## Abstract

Klippel–Feil syndrome is a rare congenital bone disorder characterized by an abnormal fusion of two or more cervical spine vertebrae. Individuals with Klippel–Feil syndrome exhibit diverse clinical manifestations, including skeletal irregularities, visual and hearing impairments, orofacial anomalies, and anomalies in various internal organs, such as the heart, kidneys, genitourinary system, and nervous system.

This case report describes a 12-year-old Pashtun female patient who presented with acute bilateral visual loss. The patient had Klippel–Feil syndrome, with the typical clinical triad symptoms of Klippel–Feil syndrome, along with Sprengel’s deformity. She also exhibited generalized hypoalgesia, which had previously resulted in widespread burn-related injuries. Upon examination, bilateral optic disc swelling was observed, but intracranial pressure was found to be normal. Extensive investigations yielded normal results, except for hypocalcemia and low vitamin D levels, while parathyroid function remained within the normal range. Visual acuity improved following 2 months of calcium and vitamin D supplementation, suggesting that the visual loss and optic nerve swelling were attributed to hypocalcemia. Given the normal parathyroid function, it is possible that hypocalcemia resulted from low vitamin D levels, which can occur after severe burn scarring. Furthermore, the patient received a provisional diagnosis of congenital insensitivity to pain on the basis of the detailed medical history and the findings of severe and widespread loss of the ability to perceive painful stimuli, as well as impaired temperature sensation. However, due to limitations in genetic testing, confirmation of the congenital insensitivity to pain diagnosis could not be obtained.

This case highlights a rare presentation of transient binocular vision loss and pain insensitivity in a patient with Klippel–Feil syndrome, emphasizing the importance of considering unusual associations in symptom interpretation.