Autoimmune thrombocytopenic purpura in pregnancy: maternal risk factors predictive of neonatal thrombocytopenia.

Pregnancy in ATP women is not unusual. The problem of this association concerns the possibility of disease transmission to the fetus due to the crossing of maternal antiplatelet antibodies through the placenta. Maternal risk factors predictive of neonatal thrombocytopenia, can be identified as follows: severe thrombocytopenia, previous splenectomy, high titre of PA-IgG and/or SPB-IgG. In 63 pregnancies in ATP patients, we have evaluated whether the above maternal risk factors, considered in the third trimester, can provide useful criteria for the prediction of neonatal thrombocytopenia. In the third trimester, the distribution of maternal risk factors was as follows: 0 in 7 cases, 1 in 27 cases, 2 in 15 cases, 3 in 12 cases, 4 in 2 cases. From a statistical evaluation, the neonatal platelet values and the maternal risk factors seem inversely correlated (r -0.437; p = 0.0005). In particular, neonatal and maternal platelet count correlated positively (r = 0.249; p = 0.025); moreover, neonatal platelet count correlated negatively with Splenectomy (r = -0.209; p = 0.05), PA-IgG (r = -0.401; p < 0.0005) and SPB-IgG (r = -0.338; p < 0.005). We tried to apply a multiple regression model for all the above parameters which appears statistically significant (p = 0.001); the variability was about 30%. This regression model could be validated if applied to a larger number of cases, and it could represent an alternative to the invasive methods used for the diagnosis of neonatal thrombocytopenia.

Performance of sequential arm movements with and without advance knowledge of motor pathways in Parkinson's disease.

Patients with Parkinson's disease are slower than normal subjects in executing sequential arm movements, and their bradykinesia worsens as the execution of motor sequences progresses. In parkinsonian and normal subjects, we studied the execution of two types of fast sequential arm movements. The subjects had to perform a motor sequence following with their arm a path marked by six targets on a screen. In one experimental condition, they performed the motor sequence without advance knowledge of its path and executed each submovement in response to the consecutive appearance of the targets on the screen (unknown motor sequences). In the other condition, all the targets appeared simultaneously on the screen before the subject moved, and the subject internally determined when to execute each submovement (known motor sequences). Patients were slower than normal subjects in executing both sequences. Patients and normal subjects were faster in executing known than unknown sequences, but the patients' percentage of total movement time diminished less. During the unknown condition, both groups tended to lengthen submovement duration whereas, during the known condition, both groups tended to correct this trend. Patients performed submovements during both sequences with longer acceleration phases. The submovement symmetry ratio of the velocity profile changed according to the direction of movement (up or down). We conclude that these findings depend mainly on the model of movement execution. They also suggest that patients with Parkinson's disease have more difficulty in executing internally determined than externally triggered sequential movements.