Paraneoplastic stiff-person syndrome, heterotopic soft tissue ossification and gonarthritis in a HLA B27-positive woman preceding the diagnosis of Hodgkin's lymphoma.

Paraneoplastic neurologic syndromes associated with Hodgkin's lymphoma include the stiff-person syndrome. A case of stiff-person syndrome is reported who first presented with muscular hyperactivity and acute respiratory failure followed by heterotopic soft tissue ossification and acute seronegative gonarthitis. Initial improvement of a tetanus-like clinical picture was achieved with benzodiazepam given by continuous infusion for analgo-sedation to mechanically ventilate the patient followed by baclofen after successful weaning. The patient was HLA B27 positive and on conventional testing no autoantibodies were detected including anti-glutamic acid decarboxylase antibodies (anti-GAD). Months later in the absence of signs of stiff-person syndrome, mediastinal lymphadenopathy and pleural effusions developed which were diagnosed as classical Hodgkin's lymphoma that was successfully treated with polychemotherapy. No relapse of paraneoplastic neurologic syndromes was seen after two years of lymphoma remission. The case illustrates that stiff-person syndrome may precede the clinical appearance of symptomatic Hodgkin's lymphoma.

An MRI-compatible surgical robot for precise radiological interventions.

OBJECTIVE: A variety of medical robots have been developed in recent years. MRI, including MR angiography and morphological imaging, with its excellent soft-tissue contrast is attractive for the development of interventional MRI-guided therapies and operations. This paper presents a telerobotic device for use in CT- and/or MR-guided radiological interventions. A robotic device for precise needle insertion during MR-guided therapy of spinal diseases will be briefly described. MATERIALS AND METHODS: Actuation of robots in an MRI environment is difficult due to the presence of strong magnetic fields. Therefore, the robot was constructed of nonmagnetic materials. The system frame was built from polyether ether ketone (PEEK) and fiber-reinforced epoxy, and actuated using ultrasonic and pneumatic motors. Completely MR-compatible sensors were developed for positioning control. RESULTS: Accuracy evaluation procedures and phantom tests were performed, with the required accuracy of approximately 1 mm being achieved and no significant artifacts being caused by the robotic device during MR image acquisition.

MR-compatible assistance system for punction in a high-field system: device and feasibility of transgluteal biopsies of the prostate gland.

We present the first cadavic study results concerning the feasibility of the use of an MR-guided assistance system, Innomotion (Innomedic, Herxheim, Germany), for accurate and consistent placement of percutaneous needles in the prostate gland. The MR-compatible assistance system consists of a C-arch, guiding arm and application module (AMO). T1-weighted fast low angle shot (FLASH) 2-D-GRE sequence (TR/TE=110/4 ms) and T2-weighted turbo spin-echo (TSE)-sequences (TR/TE=3200/97 ms) in transversal orientation were used for the monitoring of the punction of the prostate gland. Planning and control of the intervention is to be made outside the scanner room on a desktop computer that receives DICOM images from the scanner. Servopneumatic drives move the AMO to the insertion point. The physician has to introduce the punction needle manually. The mean deviation of the needle tip to the target in a gel phantom was 0.35 mm. An accurate punction of the prostate gland can easily be performed using this system with a transgluteal access. The T2-weighted images are superior for the evaluation of the prostate anatomy and the needle position during the interventions. In conclusion, our preliminary results indicate that this MR-guided assistance system is suitable for an accurate transgluteal needle placement in the prostate.