Epi-arachnoidal drug deposit: A rare complication of intrathecal drug therapy

Intrathecal (IT) drug application is accepted as a highly effective treatme nt option for various neurological conditions. Technical risks and potentia lly dangerous complications require appreciation. We present the case of a patient treated with IT recombinant, human brain-derived neurotrophic facto r (rhBDNF) as an experimental therapy for amyotrophic lateral sclerosis (AL S). Five nays after starting the IT drug infusion, she complained of severe headache and nausea. Radiological studies suggested the catheter was locat ed within the epiarach noidal space. A deposit of more than 10 ml secluded from the subarachnoidal space was found within this space. TT contained a h igh concentration of the applied drug. Revison of the catheter resulted in complete recovery from symptoms and IT infusion could be continued. The epi -arachnoidal positioning of a spinal catheter is a potential cause for trea tment failure. If the membrane around the fluid deposit ruptures, the drug could be released into the subarachnoidal space, with the consequence of a potentially life-threatening complication. (C) U.S. Cancer Pain Relief Comm ittee, 1999.