Cortical Visual Impairment in CDKL5 Deficiency Disorder

Area of Science:

• Neuroscience
• Genetics
• Ophthalmology

Background:

• CDKL5 deficiency disorder (CDD) is a genetic developmental encephalopathy.
• Cerebral visual impairment (CVI) is a frequent and significant feature in CDD patients.
• Previous studies suggested a link between visual impairment and neurodevelopmental outcomes, but lacked systematic assessment.

Purpose of the Study:

• To evaluate the clinical and electrophysiological profile of CVI in CDD patients.
• To correlate visual function aspects with neurodevelopmental and epileptic features.

Main Methods:

• Included 11 CDD patients from the National Pathology Registry.
• Conducted neurological exams, disease-specific functional assessments, and structured visual function evaluations.
• Utilized pattern reversal visual evoked potential (VEP) and video-EEG monitoring.

Main Results:

• All 11 patients exhibited impaired visual function, with deficits in visual fields, acuity, contrast sensitivity, and stereopsis.
• Pattern reversal VEP was abnormal in approximately 80% of patients.
• No significant correlation was found between CVI severity and age, psychomotor development, or EEG abnormalities, though less abnormal EEGs trended with better visual results.

Conclusions:

• CVI is a major, multifaceted feature of CDD, impacting various behavioral and electrophysiological aspects.
• Larger studies are needed to determine the prognostic value of EEG severity for visual and developmental abnormalities in CDD.