Disconjugate

The disconjugate nystagmus, head titubation, and torticollis of spasmus nutans have been reported as indisinguishable from those associated with glioma of the anterior visual pathway.

In other words, the subject learned to preprogram intrasaccadic and postsaccadic disconjugate movements independent of any immediate disparity cues.

Absence of parallel movement of the eyes indicates disconjugate gaze disturbance (Figure 12.8).

The aim of this paper consists on the study of the following fourth-order operator: \begin{equation}\label{Ec::T4} T[M]\,u(t)\equiv u^{(4)}(t)+p_1(t)\,u"'(t)+p_2(t)\,u"(t)+M\,u(t)\,,\ t\in I \equiv [a,b]\,, \end{equation} coupled with the two point boundary conditions: \begin{equation}\label{Ec::cf} u(a)=u(b)=u"(a)=u"(b)=0\,. \end{equation} So, we define the following space: \begin{equation}\label{Ec::esp} X=\left\lbrace u\in C^4(I)\quad\mid\quad u(a)=u(b)=u"(a)=u"(b)=0 \right\rbrace \,. \end{equation} Here p#95;1#92;inC³(I) and p#95;2#92;inC²(I). By assuming that the second order linear differential equation \begin{equation}\label{Ec::2or} L_2\, u(t)\equiv u"(t)+p_1(t)\,u'(t)+p_2(t)\,u(t)=0\,,\quad t\in I, \end{equation} is disconjugate on I, we characterize the parameter's set where the Green's function related to operator T#91;M#93; in X is of constant sign on I#92;timesI.