Dexterity deficit due to current training models, dexterity decay due to lack of practice, and situational stress related to the clinical environment may combine to impede effective training and confident use of endoscopes in airway management.
The number of sites of infusion of ibotenic acid close to proximal territories was plotted in Fig. 7a for the individual monkeys as a function of the effects observed on the behavioral tasks described above (no effect = 0; deficit observed for one manual dexterity task = 1; deficit observed for two manual dexterity tasks = 2).
The data in Fig. 7 thus suggest that the deficits of manual dexterity with the ipsilesional hand do not result from a systematic spread of ibotenic acid to proximal territories in the monkeys exhibiting more deficit than the other animals.
Occupational exposure to lead among adults is associated with poorer neurobehavioral test scores and with deficits in manual dexterity, executive ability, verbal intelligence, and verbal memory (Schwartz et al. 2000).
When plotting the average distance between the infused sites and the closely located proximal territories with respect to the number of manual dexterity tasks for which a deficit was observed (Fig. 7b), there is no systematic relationship either.
In accordance with such a small anatomical disruption, the contralesional hand showed only a small deficit in manual dexterity for a couple of days, and the animal's behavioral performance returned to pre-lesion levels after just 5 days.
There is no correlation between the number of sites infused close to proximal territories (elbow, shoulder) and the number of tasks for which an ipsilesional deficit of manual dexterity was observed.
In contrast to the expected dramatic, complete deficit of manual dexterity of the contralesional hand that persists for several weeks, the impact on the manual dexterity of the ipsilesional hand was generally moderate (but statistically significant) and, when present, lasted less than 20 days.
The transient deficits observed above for the manual dexterity with the ipsilesional hand after unilateral motor cortex lesion may be due to a dysfunction of cortical territories giving rise to the uncrossed corticospinal projection, involved mainly in the control of proximal muscles (e.g. Lemon 2008).
Deficits in spatial memory and decreased manual dexterity have been noted in monkeys injected with manganese sulfate (Schneider et al. 2006); delayed neurodevelopment has been reported in newborn rat pups orally supplemented with Mn (Tran et al. 2002).
