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UPPER LIMBS MOVEMENTS BEFORE AND AFTER INTRATHECAL BACLOFEN
PUMP IMPLANT
Federica Sibella1, Manuela Galli1, Francesco Motta2, Marcello Crivellini1 Bioengineering Dept., Politecnico di Milano, Milano, Italy Paediatric Orthop. Dept., "V.Buzzi" Hospital, Milano, Italy performed twice for each limb to assess data INTRODUCTION
consistency. These movements were chosen on the basis of daily activity usefulness. Intrathecal baclofen implant (ITB) consists of a pump that is implanted subcutaneously in the abdominal wall with a catheter surgically placed into the subarachnoid space. By delivering the baclofen drug directly to the spinal cord, higher concentrations can be placed near the target with lower doses than Figure 1: marker positioning
the oral route. The drug dose is adjusted to From kinematic data, the range of motion minimizing weakness. Main indication for intrathecal baclofen implant are non-walking each movement in each direction (x, y and z), cerebral palsy (CP) patients as some clinical then the percentage difference between upper works assessed1. It results very important to evaluate the outcome of this treatment using a test able to quantify the improvement in The aims of this pilot study are to develop a these data, the area of the ellipsis that characterise the movement in each plane (xy movements and to apply it to non-walking CP = frontal plane, xz = horizontal plane and yz = subjects before and after ITB treatment. sagittal plane) and the volume of the ellipsoid calculated and the differences between each patient’s situation before and after ITB were (average age: 10 years, range 6-18 years) were analysed before ITB, 5 of them were RESULTS AND DISCUSSION
analysed also after ITB. In order to analyse The severity of the initial conditions was different from subject to subject, therefore they couldn’t be analysed as a group. A (Figure 1): on the acromions, elbows, wrists, preliminary subdivision could be made using the clinical evaluation data, which allowed us Each subject was asked to perform 3 different to discriminate between very severe and less movements, starting from a fixed position severe initial conditions. On this basis, (moving the CO forward to the self-selected subjects 323 and 324 started from the worst initial conditions, while subjects 438, 471 and CO laterally to the self-selected maximum 474 started from better conditions as far as extension and back; taking the CO to the After ITB implant the ROMs of subjects 323 and 324 result increased in all 6 requested tasks. In Table 1, %∆ROMs for all tasks are An explanation for this contrast in the results evidenced. The calculated ellipsis area (that can be given in terms of changes in the motor ability induced by ITB. In fact, in very severe improves for all the movements: in Figure 2, the ellipsis relative to the object motion is impaired patients seem to move in a more plotted for one subject taken as example. “random” way, sometimes improving and sometimes diminishing ROM in the different contributes to relax the subject’s muscles overall, thus, applying the same power to obtain a movement that was already possible for the patient before the treatment, the subject is not able to coordinate him/herself Table 1: %∆ROMs for subjects 323 and 324
“random” in respect to the previous situation. It could be very interesting to repeat upper limbs analysis after a few months, to evaluate if the effects of physical rehabilitation after ITB could lead to new movement coordination. On the other hand, very impaired subjects, who couldn’t perform many tasks before the treatment, improve their motor ability leading to a situation similar to the one showed by the less impaired subjects before ITB. Figure 2: example of how the ellipsis area
changes after ITB in a very severe impaired subject, lateral movement: range x increased movements in non-walking patients before and range z diminished. Above: before ITB; and after intrathecal baclofen implant. The first results show a good improvement in terms of ROM and planarity of the movement initial conditions. Instead, the subjects who showed better initial conditions seem to move after the treatment in a less coordinate way. This result can be explained observing that these patients are not used to their more “relaxed” muscular conditions, thus they use the same force and power as before, but they cannot perfectly control their movements. Table 2: %∆ROMs subjects 438, 471, 474
REFERENCES
On the contrary, the three subjects that reveal a better initial condition behave apparently in Penn RD et al., Intrathecal baclofen for severe a random way, only the first showing a visible spasticity, Lancet, 2:125-127, 1985 improvement in the ROM (see Table 2, only object %∆ROM are reported).

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