1. Histological Findings After Long-Term Infusion of Intrathecal Ketamine for Chronic Pain 
Martin Stotz, MD, Hans-Peter Oehen, MD, Helmut Gerber, MD 
Journal of Pain and Symptom Management 
Volume 18, Issue 3, Pages (September 1999)
DOI: /S (99)00069-X

2. Fig. 1
Management trials and related pain scores on pain scale during hospitalization in a 72-year-old patient with pain due to peritoneal malignant mesothelioma
Journal of Pain and Symptom Management  , DOI: ( /S (99)00069-X)

3. Fig. 2
Detailed infusion scheme for intrathecal treatment with ketamine
Journal of Pain and Symptom Management  , DOI: ( /S (99)00069-X)

4. Fig. 3
Severe lymphocytic vasculitis of spinal vessel after long-term intrathecal infusion of ketamine with preservative, normal medullary tissue; stained hematoxylin–eosin
Journal of Pain and Symptom Management  , DOI: ( /S (99)00069-X)

5. Fig. 4
Normal nerve sheaths with central axon, no signs of demyelinization or vacuolization in the same patient; stained Klüver-Barrera
Journal of Pain and Symptom Management  , DOI: ( /S (99)00069-X)