Central nervous system reactions to cervical myelography

Area of Science:

• Neurology
• Radiology
• Pharmacology

Background:

• Cervical myelography is a diagnostic procedure that can cause side effects.
• The specific contrast media used may influence the incidence and type of side effects.
• Understanding these differences is crucial for patient safety and procedure optimization.

Purpose of the Study:

• To compare the side effects of metrizamide and iohexol in cervical myelography.
• To investigate the neurological effects of these contrast agents on the central nervous system.
• To determine the location and nature of adverse reactions.

Main Methods:

• A double-blind, prospective study involving 38 patients undergoing cervical myelography.
• Neurologic examinations, electroencephalography (EEG), brainstem evoked response (BER), somatosensory evoked responses (SSER), and continuous reaction times were performed.
• Assessments were conducted before and at 6 and 24 hours after myelography with either metrizamide or iohexol.

Main Results:

• A significant difference in the incidence of side effects (headache, dizziness, nausea, neck pain) was observed between metrizamide and iohexol.
• High frequency of EEG deteriorations in patients with adverse reactions suggests a cerebral cortex effect.
• Normal SSER and discrete BER affection, along with motor root blockade symptoms, indicate a contrast effect on motor pathways.

Conclusions:

• Side effects of cervical myelography are not solely due to spinal puncture but are influenced by the contrast medium.
• Metrizamide and iohexol exhibit different effects on the central nervous system, potentially due to metabolic differences.
• Adverse reactions appear localized to the cerebral cortex and motor pathways, influenced by patient positioning during the procedure.