Gadolinium is evident in neurons. Description of overall deposition in brain and presence in other cells.

I have written in a number of blogs my opinion of the presence of Gd in various tissues. I have emphasized that the presence in actual brain cells (neurons) is of critical importance. In general for controversial subjects I like to see 3 descriptions from separate groups that are independent of each other.. At present 3 different human studies of brain localization are not present.

So I have to rely on the one report that describes neuron localized Gd:

Gadolinium Deposition in Human Brain Tissues after Contrast-enhanced MR Imaging in Adult Patients without Intracranial Abnormalities

• Robert J. McDonald , 

• Jennifer S. McDonald, 

• David F. Kallmes, 

• Mark E. Jentoft, 

• Michael A. Paolini, 

• David L. Murray, 

• Eric E. Williamson, 

• Laurence J. Eckel

Author Affiliations

Published Online: Jun 27 2017

In this paper that included just 5 patients, 2 were found to have Gd not only in neurons, but in the nuclei of neurons. This translates to 40%. This study was published 8 years ago. Because of the importance of this finding it is surprising (shameful) that further studies with larger numbers have not been performed.

Let us back track to other reports on brain deposition in animals and humans. This is not the same as localization into cells themselves. Most of the Gd retention is in the tissues around cells. I will summarize below what my estimate is of the localization of Gd in the brain. It is critical to understand that Gd in the body arises from the power injection of Gd (atleast 2 ml/second) at MRI. Gd is delivered at this rate in order to maximize the demonstration of tissue enhancement of tumors, inflammation, and cells by forcing Gd into the extracellular matrix..

30% of Gd is trapped in the endothelium and in the basement membranes of blood vessel endothelium. Most, 90% is in the extracellular location. Probably 10% in cells of the endothelium. Most of this intracellular Gd will be bound in lysosomes (small envelopes) in the cytoplasm..

60% of retained Gd has extended beyond the endothelium The mud tracks of where Gd was located when injected. 90% not in cells, but in the space around cells, the extracellular matrix, 9 % in the brain support cells, glial cells and white blood cells (most in lysosomes in the cytoplasm, 1 % in the nucleus). Approximately 1 % of Gd in brain is in neurons themselves, with most of the Gd in lysosomes in the cytoplasm and a tiny amount in the nucleus.

All that said, there are no studies that have been designed to look for the actual spaces deposition of Gd has occurred. This is obviously something that the MR contrast companies should have done/ should do.

There are a lot of ironies to all this. The McDonald paper described above, showing that Gd deposits in the nuclei of neurons, is not from the restaurant chain of the same name, but from a major US clinic also starting with M, which notoriously does not think GDD can occur.

I would say to them: you are injecting a foreign molecule, bound to a heavy metal, directly into patients' veins at high velocity, some of which dissociates. You don't think some people's immune systems will react badly to this? What the hell are you thinking? In fact as you consider this, and recognize that Gd actually gets into neurons, that the incidence of toxicity from persistent presence of Gd, GDD, is not more common than it is (1 in 10, 000 of all comers). This is approximately the same incidence of Parkinson's disease development in patients receiving GBCAs reported in a large South Korean study. I have recently described this paper. I would term this condition Gd-induced Parkinson's Disease.

Papers have been published describing deposition of Gd within cells of nonbrain origin. White blood cells that engage in phagocytosis (swallowing foreign entities) have been shown to contain Gd in them (obviously). GBCAs that are also eliminated by the biliary system show retention of Gd in hepatocytes (obviously).

So Gd is present in the nuclei of neurons.. At this time, my opinion is that this is less than 1 % of the Gd retained in the brain. Most of the symptoms of cognitive impairment in my opinion are due to systemically cisculated cytokines, which explains why many brain symptoms tend to recover relatively early, and earlier than symptoms in other body regions. More studies have to be performed in which their purpose is to define exactly where Gd is localized. I may be wrong in saying that very little Gd that is deposited in the brain is actually retained in neurons.

Richard Semelka, MD