Re: Can the myelin sheath be damaged over time from radioactive isotopes?

For this question I had to ask a few other neurologist and 
neuroscientists. This is the combined response from three people.

First, the question, "Can the myelin sheath be damaged over time from 
radioactive isotopes?"  is different than the one really asked " is 
it possible that this dye could cause a problem?"


Most myelograms done years ago were with a contrast dye called pantopaque, 
which, to my knowledge, is neither radioactive nor neurotoxic. (one 
person's view).
However, there are some reports about toxic effects of this dye and I have 
provided the references below as well as abstracts in 2 cases. Some of 
these articles might be hard to obtain the full report and read since one 
is in Portuguese and the other in German.

So a quick reply, is that there is generally no problem from having the 
contrast dye remain in the body.  The more involved answer begins with 
finding out with 
certainty what is the name of the contrast material the individual 
received?  Likely, the myelogram reports would have this information.  
Next, would be a review of literature concerning the agent used to see if 
there are any reports of problems associated with it.  A neuroradiologist 
who has been in practice for at least 10 years would probably be familiar 
with literature concerning older myelogram dyes.


Report #1

Constrictive arachnoiditis after pantopaque myelography causing 
syringomyelia and paraparesis: case report

Arq Neuropsiquiatr 2001 Sep;59(3-A):619-22

[Article in Portuguese]

Silva JA, Taricco MA, Brito JC, Neves VD, Farias RL.

Servico de Neurologia e Neurocirurgia, Hospital Santa Isabel, Joao Pessoa, 
PB, Brasil.

We present an unusual case of thoracic constrictive arachnoiditis after 
pantopaque myelography, used 10 years before in the diagnosis of 
intradural arachnoid cyst.

Report #2

Symptomatic pulmonary complications from liquid acrylate embolization of 
brain arteriovenous malformations.

AJNR Am J Neuroradiol 1995 Jan;16(1):19-26

Pelz DM, Lownie SP, Fox AJ, Hutton LC.

Department of Diagnostic Radiology, University Hospital, University of 
Western Ontario, Canada.

PURPOSE: To describe symptomatic pulmonary emboli from brain arteriovenous 
malformation embolization with liquid acrylates and to analyze the reasons 
for these complications and describe preventive techniques. METHODS: The 
clinical records of 182 patients embolized with acrylate glue since 1978 
for treatment of brain AVMs were searched for evidence of symptomatic 
pulmonary complications. Originally iso-butyl-2-cyanoacrylate and more 
recently n-butyl-2-cyanoacrylate were used in all patients. Arteriovenous 
malformation morphology, amounts and techniques of glue injection, and 
clinical and radiologic investigations in the symptomatic patients were 
recorded. RESULTS: Three patients had pulmonary symptoms within 48 hours 
of glue injection. One patient with a left frontal arteriovenous 
malformation had embolization with an isobutyl-2-
cyanoacrylate/pantopaque/acetic acid mixture; severe pleuritic chest pain 
developed 2 days later. One patient with a left temporal and one with a 
left cerebellar arteriovenous malformation had embolization with n-butyl-2-
cyanoacrylate/lipiodol mixtures; a cough, pleuritic chest pain, and bloody 
sputum developed in both within 24 hours. Two patients experienced a 
significant drop in PO2. No flow-arrest techniques were used for any of 
the injections in these three patients. All patients demonstrated 
significant changes on chest x-ray and CT chest examinations. All were 
treated conservatively and recovered spontaneously. CONCLUSIONS: 
Symptomatic pulmonary complications can occur after acrylate glue 
injection, particularly when delivery systems without flow arrest are used 
in high-flow vascular brain lesions. Techniques using acetic acid to delay 
polymerization time and "sandwich" techniques in which glue is pushed with 
dextrose are also more susceptible to this complication.

Report # 3
Complications following myelography with positive contrast media 
(Pantopaque, Amipaque). Pathomorphologic findings in 2 fatal cases

Zentralbl Neurochir 1985;46(2):141-50
[Article in German]

Baessler B, Lahl R.

It is reported on three patients which suffered from severe side effects 
after cervical myelography using Amipaque (cases 1 and 3) and Pantopaque 
(case 2). In 2 cases death occurred after 13 days (case 2) respectively 17 
days (case 3). Worsening of the clinical symptoms appeared in all cases 
within four days after myelography. In the first 2 cases inflammatory 
alterations prevailed whereas in the third case complications probably 
based on mechanical irritations of nerval and vascular structures. In the 
2 lethal cases autopsy offered a prostatic cancer with vertebral and 
intraspinal metastases respectively syringobulbia and cervical 
syringomyelia beside an ependymoma of the cervical spinal cord as 
incurrable complaints. The various side effects and complications after 
myelography using positive contrast media as well as their causes are 
discussed.

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