Divided visuo-spatial attention systems with total and anterior callosotomy.

The role of the corpus callosum in the inter-hemispheric integration of the visuo-spatial attention system, was investigated in patients with a total callosotomy or with an anterior callosal section. Subjects produced simple reaction times (RTs) to visual targets shown to the left or right visual hemifield. Preceding the target by an interval of 500 ms, arrow cues predicting the target location were shown left and right of the point of ocular fixation.

Tuberculous spondylitis: a retrospective study on a series of 12 patients operated on in a 25-year period.

Background: The incidence of tuberculous spondylitis, which had declined steadily for over 40 years in our countries, started increasing again in the eighties, paralleling the resurgence of pulmonary tuberculosis. Therefore it has become a matter of discussion in contemporary literature, because it can be a diagnostic challenge and, in spite of its severe neurological complications, it is a potentially curable illness.

Methods: In this retrospective study the authors report their experience concerning 12 patients operated on in a 25-year period because of serious cord compression from thoracic (9 cases) and cervical (1 case) tuberculous spondylitis or from thoracic tubercular epidural lesion (2 cases).

Callosal and cortical contribution to procedural learning.

Acallosal and callosotomized subjects usually show impairments on tasks requiring bilateral interdependent motor control. However, few studies have assessed the ability of these subjects to learn a skill that requires the simultaneous contribution of each hemisphere in its acquisition. The present study examined whether acallosal and callosotomized subjects could learn a visuomotor skill that involved a motor control from either both or a single hemisphere.

Mutism in 36 patients who underwent callosotomy for drug-resistant epilepsy.

Thirty-six drug-resistant epileptic patients submitted to callosotomy were studied. Anterior callosotomy was performed in 27 patients, total two-stage callosotomy was performed in 8 patients and 1 patient had only posterior callosotomy. We found mutism in 10 patients (2 after complete callosotomy and 8 after anterior section).

EEG Patterns after callosotomy.

In 36 patients with drug-resistant epilepsy submitted to anterior callosotomy (27 cases), to two-stage total callosotomy (8 cases) and to posterior callosotomy (1 case) the EEG variations concerning background activity, focal activity and sharp-waves (SW) bisynchronous activity were evaluated. EEG modifications observed after callosotomy are the following: background rhythm tends to be better organised as spectral analysis demonstrated, this finding usually coincide with reduction of bisynchronous discharges. It appears that improvement in background activity cannot be correlated with outcome, but it seems to be to some extent since at the same time cognitive functions also seem to improve; however, this last aspect need to be checked in much larger series.