99mTc-sodium pertechnetate permeation into cerebrospinal fluid.

Area of Science:

• Neurology
• Radiochemistry
• Infectious Diseases

Background:

• The blood-brain barrier (BBB) integrity is crucial for central nervous system (CNS) health.
• Assessing BBB function can involve analyzing substances in blood and cerebrospinal fluid (CSF).
• Previous literature on BBB permeability and its relation to pathology is controversial.

Purpose of the Study:

• To investigate the frequency of abnormal technetium-99m pertechnetate (99mTc-sodium pertechnetate) entry into the CSF.
• To determine if abnormal 99mTc-sodium pertechnetate CSF levels correlate with specific pathologies, particularly CNS tuberculosis.
• To evaluate the utility of plasma-to-CSF ratios for assessing BBB integrity.

Main Methods:

• 51 patients underwent intravenous administration of 0.5-10 mCi 99mTc-sodium pertechnetate.
• Plasma-to-CSF ratios were measured 4 hours post-injection.
• A 82Br partition test was conducted 48 hours after oral NH82Br administration for correlation.

Main Results:

• Patients with active CNS tuberculosis (n=23) showed a significantly lower mean pertechnetate plasma-to-CSF ratio (32.12) compared to non-tuberculous subjects (n=28, 144.63).
• The 82Br partition test results corroborated the pertechnetate findings, with lower plasma-to-CSF ratios in CNS tuberculosis patients (1.25) versus controls (3.32).
• Elevated CSF 99mTc-sodium pertechnetate suggests impaired BBB integrity.

Conclusions:

• Impaired blood-brain barrier integrity, evidenced by increased CSF pertechnetate, is a common finding in active CNS tuberculosis.
• Plasma-to-CSF ratios of 99mTc-sodium pertechnetate can serve as a valuable indicator of BBB dysfunction in neurological conditions.
• These findings support the use of radiotracer studies for diagnosing and understanding CNS pathologies affecting the BBB.