Neurophysiological and intellectual evaluation of patients with beta-thalassemia major

ABSTRACT

Anemia and its complications represent a major health problem in children. Beta-Thalassemia major [BTM] is a chronic genetically determined hematological disorder characterized by ineffective erythropoiesis, peripheral hemolysis and severe anemia and they require regular blood transfusions. The aim of the present study is to evaluate the neurophysiological and intellectual aspects of patients with BTM who are clinically have no CNS affection. The study included 33 patients with BTM 23 males and 10 females, their mean age was [8.00 +/- 3.02 years], who attended hematology unit of pediatric hospital, Assiut university in the period between January and April 2006. In addition to 30 apparently healthy children of cross matched age and sex as a control. A thorough history full clinical examination and detailed neurological history and examination were carried out. Evaluation of the hemoglobin level, serum Iron and serum ferritin were done as well as EEG and IQ. In the present study, Hb level was significantly lower in patients [6.9 +/- 1.2 gm/dl] than controls [11.4 +/- 0.7 gm/dl] with P<0.001, serum iron was significantly higher in patients [186.3 +/- 60.9 micro g/dl] than controls [91.9 +/- 22.1 micro g/dl] with P<0.001 and serum ferritin was significantly higher in patients [2580.00 +/- 576.9 micro g/dl] than controls [435.6 +/- 112.9 micro g/dl] with P<0.001. Total as well as performance I.Q were significantly lower in patients than controls with p-value <0.001 for each, Mean value of total I.Q were 88.3 +/- 8.1 for patients and 98.7 +/- 6.4 for controls. Performance I.Q were 81.7 +/- 9.1 for patients and 97.8 +/- 6.1 for controls. A significant negative correlations was present between serum iron and total I.Q [r=-0.67 and p<0.001] as well as performance I.Q [r=-0.45 and p<0.01]. There were no significant correlations between serum ferritin and I.Q [total, verbal or performance]. A significant positive correlation between mean Hb level in the last 2 years and total I.Q [r=0.68 and P<0.001], performance I.Q [r=0.47 and p<0.01] and verbal I.Q [r=0.41 and p< 0.05]. EEG background activity was normal in 48.5% and shows different grades of slowing in the rest of cases. There were a significant increase in slow waves as theta waves [39.7 +/- 23.4 and controls 11.8 +/- 6.9 with P-value <0.001] and delta waves [9.6 +/- 8.8 and controls 4.4 +/- 4.6 with p-value <0.05]. While fast waves of EEG were significantly decreased as alpha waves [12.12 +/- 9.28 and controls 19.7 +/- 6.7 with p-value <0.001] and beta waves [38.48 +/- 22.24 and controls 64.1 +/- 12.28 with p-value <0.001]. A significant positive correlation was present between Hb level and alpha waves [r=0.74 and P<0.001], significant-ve correlation between Hb and theta waves [r=0.65 and P<0.001] and a significant positive correlation between Hb and beta waves [r=0.66 and P<0.001]. C.N.S. is one of the important systems affected by repeated blood transfusions in BTM patients leading to lowering of I.Q scores especially performance skills and also affect EEG and these effects starts silently and progress and so, early detection of CNS affection in BTM patients is recommended for early intervention and to maintain good quality of life as well as to reach a satisfactory levels in learning