In addition skew deviation was noted in eight cases ( 10, 15), convergence insufficiency in seven cases ( 10, 13, 16) and ptosis was present in seven cases. The most common oculomotor defect associated with the dynamic oval pupil consisted of limited vertical eye movements, particularly upward gaze, which was found in ten cases ( 9, 10, 13, 16) in six of these cases the Doll's head maneuver did not elicit reflex movement of the eyes in the vertical plane, implying a nuclear or infranuclear deficit ( 7, 10) but in the remaining cases the assumption is that the deficit was supranuclear. A “dynamic oval pupil” was present in all 20 cases: it was bilateral in 15 and unilateral in five. The pupil light reflex was absent in at least one eye in ten cases, sluggish in six and no information was available in the rest (for each of these cases we have considered the less reactive of the two pupils). Of those five, the cause was tumoral in two ( 13, 16), multiple sclerosis in one ( 16), an AV fistula compressing the midbrain in another ( 11) and in the fifth one it was due to a midbrain embolus ( 10).Īnisocoria, when it was recorded, was present in 15 cases, in another case pupillary size varied independently in the two eyes ( 7), and pupils were equal in size in the remaining four cases. There was a similar range of ages for cases caused by vascular insufficiency (30–86) and intra-axial hemorrhage (53–79) but cases caused by tumor were significantly younger (13-42) The state of consciousness varied between stupor and coma in 14 of the 20 cases, somnolence in one ( 10) and was not altered in five ( 10, 11, 13, 16). Of the cases reviewed, 15 of these were male and 5 were female. Their clinical characteristics were then tabulated in order to bring out their commonality ( Table 1). A total of 95 cases were collected from these reports, but their perusal disclosed only 20 cases that provided a minimum of clinical data that justified their inclusion on this study. It yielded 10 reports conforming to our definition of “ Dynamic oval pupil” ( 7– 16). Materials and MethodsĪ careful search of the literature for the headings of “ midbrain corectopia,” “pupillary ectopia,” and “ oval pupil”' was carried out. It is in that setting that the detection of a dynamic oval pupil finds its significance. Nevertheless, in certain clinical situations, where the neurological status of the patient is unstable, intensive clinical neuromonitoring remains indispensable, because current imaging technology cannot provide the required minute-to-minute assessment, it is expensive and it is not always available. Since the 1970's, with the advent of computed tomography (CT) and later followed by magnetic resonance imaging (MRI), a significant decline in the interest and in the time devoted to a detailed neurological examination has become unfortunately evident in daily practice. This type of dynamic oval pupil has been considered a transitional state preceding the mydriatic and fixed pupil of a full-blown transtentorial herniation ( 8), and consequently, when detected, should raise the alert of the clinician to act on an urgent basis. What is understood as an oval pupil in the neurological arena, usually presents itself in the midst of a severe neurological event causing midbrain-tectal dysfunction ( 7, 8) and it is a dynamic alteration of the round shape of the pupil that can occur intermittently, can change its size and/or the orientation of its major axis or return to its normal round shape while being observed, this together with varying effects on its reactivity ( 7, 9). Although corectopia and oval pupil have been usually employed, in the pertinent literature, as synonyms, we propose that these should be distinguished as two quite different conditions. It relates mostly to conditions that could be considered “static” because these are anatomically fixed pupillary deformities resulting from congenital ( 1, 2) or acquired conditions. Corectopia, defined as the displacement of the center of the pupil away from the center of the cornea, is usually encountered within the realm of Ophthalmology.
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