[Monitoring cerebrospinal fluid shunts by thermography]

The authors have used a thermographic system to evaluate cerebrospinal fluid (CSF) shunt patency. Thermographic detection of the catheter rests on the gradient that exists between the temperature of the CSF-containing tube and that of the nearby skin. The equipment consists of an infra-red sensitive camera connected to a television screen. No cooling or warming of the reservoir was performed. The entire length of the superficial part of the shunt could be explored. The present study concerns 36 thermographic examinations in 31 patients. The CSF-containing catheter was usually warmer than the skin, but in some circumstances its upper part appeared to be cooler than the skin of the head and its lower part warmer than the skin of the neck. The thermographic results are in agreement with the clinical findings and the course of the disease. The method, which is harmless, simple and easily reproducible, seems to be useful for the determination of CSF shunt patency.