Impaired awareness of behavioral limitations after traumatic brain injury.

Sixty-four traumatically brain injured patients were divided into three groups. Patients in Group I overestimated their behavioral competencies. Patients in Group II showed behavioral ratings similar to relatives' reports concerning behavioral competencies. Patients in Group III underestimated their behavioral competencies. Group I patients had greater evidence of bilateral and multiple-site lesions than group II and III patients. Speed of left-hand finger tapping was also worse in Group I than groups II and III, but other standard neuropsychologic test findings failed to separate the groups. Specific brain lesion sites were not related to group membership. Impaired awareness of behavioral limitations after traumatic brain injury may be related to neuropsychologic changes not measured by standard tests. Bilateral impairment of heteromodal cortex may be important to this phenomenon when it exists several months or years postinjury.

Facilitation of neocortical kindling by depletion of forebrain noradrenaline.

The role of forebrain noradrenaline in seizures induced by electrical stimulation of the anterior neocortex (kindling) was investigated in control rats and rats pretreated with bilateral injections of 6-hydroxydopamine (6-OHDA) into the mesencephalic trajectory of the dorsal tegmental noradrenergic bundle. Extensive depletion of forebrain noradrenaline significantly facilitated the rate of development of cortico-generalized seizures.