Objective Pupillometry as an Adjunct to Prediction and Assessment for Oculomotor Nerve Injury and Recovery: Potential for Practical Applications.

BACKGROUND: Pupillary light reflex examinations are intrinsic to any good neurological examination. Consistent evidence has shown that automated pupillometry assessments provide superior accuracy and interrater correlation compared with bedside eye examinations. Pupillary indexes such as the neurological pupil index (NPI) can also provide several hours of warning before the advent of herniation syndromes or third nerve palsy. METHODS: We determined the unique temporal relationship between NPI changes and third nerve palsy occurrence and recovery in an initially neurologically intact hospitalized patient. A 53-year-old woman presented with aneurysmal subarachnoid hemorrhage and headaches. Her aneurysm was treated surgically without complications. After lumbar drainage for hydrocephalus, she developed isolated left third nerve palsy that slowly recovered over the following weeks. Pupilometer data were obtained throughout her hospital stay. RESULTS: A total of 121 pupillary measurement sets were obtained. The NPI had decreased to an abnormal level (<3) 12 hours before she became symptomatic. The NPI also started improving 24 hours before improvement in her clinical examination. The patient did not display signs of neurological dysfunction related to vasospasm during her stay. CONCLUSION: The NPI seems to reliably correlate with third nerve function and appears to possess predictive temporal properties that could allow practitioners to anticipate neurological injury and recovery. These findings could affect the fields of neurosciences, trauma, military medicine, critical care, and ophthalmology.

Premanifest Huntington's disease: Examination of oculomotor abnormalities in clinical practice.

INTRODUCTION: Different oculomotor abnormalities have been reported to occur in premanifest Huntington's disease. The aim of this study is to investigate which oculomotor items of the Unified Huntington's Disease Rating Scale (UHDRS) are affected in premanifest individuals compared to healthy controls, and if CAG repeat length and age are correlated with oculomotor abnormalities in premanifest Huntington's disease gene carriers. METHODS: We compared baseline data of 70 premanifest individuals and 27 controls who participated in the Enroll-HD study at the Leiden University Medical Center, the Netherlands. Premanifest gene carriers were divided in individuals near to disease onset and individuals far from disease onset. RESULTS: Using a logistic regression model, only horizontal ocular pursuit of the six oculomotor items of the UHDRS was significantly more frequently affected in premanifest individuals close to disease onset compared to controls (p = 0.044, OR 13.100). Age was significantly higher in premanifest individuals with affected horizontal ocular pursuit (p = 0.016, OR 1.115) and with affected vertical ocular pursuit (p = 0.030, OR 1.065) compared to premanifest individuals without ocular pursuit deficits. CONCLUSIONS: Our results suggest that horizontal ocular pursuit is the only affected oculomotor item of the UHDRS in premanifest individuals and could be used to assess early clinical signs of Huntington's disease. Saccade initiation and saccade velocity do not seem useful for detecting differences between premanifest individuals and controls.

Oculomotor nerve injury induces nuerogenesis in the oculomotor and Edinger-Westphal nucleus of adult dog.

Technical developments have extensively promoted experimental and clinical studies on cranial nerve regeneration, but intracranial nerve recovery is still an unexplored research area compared to peripheral nerve repair. In this study, we researched whether neurogenesis occurs in adult oculomotor (OMN) and Edinger-Westphal nucleus (EWN) or not after oculomotor nerve injury. To assess cell proliferation in response to unilateral oculomotor nerve crush (ONC) in adult beagle dog, repetitive 5-bromo-2'-deoxyuridine (BrdU) intravenous injections were performed during 3 or 7 days before the dogs were euthanized 2 h after the last injection on days 3, 7, 14, and 28 post-ONC. The proliferating cell types were investigated with three cell phenotypic markers and confocal microscopy on serial sections throughout the whole extent of OMN and EWN. BrdU-positive nuclei were detected in bilateral OMNs and EWNs from 3 to 28 days after ONC with the peak value at 3 days. Confocal analysis revealed that partial BrdU-positive cells colocalized with nestin or ßIII-tubulin or GFAP, and the number of every kind of double-labeled cell maintained an increased tendency from 3 to 28 days post-ONC. Neither single-labeled BrdU-positive nuclei nor double-labeled cells were detected in the subependymal layer of cerebral aqueduct (SELCA) of all unilateral ONC dogs; also, they were not observed in the OMNs, EWNs, and SELCA of intact and sham-operated dog. These findings demonstrate that ONC can trigger continual mitotic activity, proliferation of NSCs, neurogenesis, and astrogliogenesis in the OMN and EWN of adult dogs.

Incomplete oculomotor nerve palsy in the subarachnoid space caused by traumatic brain injury.

A patient with traumatic brain injury showed incomplete oculomotor nerve palsy in the subarachnoid space. A 12-year-old girl was hospitalized after a head injury. Neuro-ophthalmic examination showed that the left eye had a ptosis and pupillary involvement. An MRI indicated an intracranial hematoma at the basilar portion of the left temple. The ptosis and pupillary involvement improved after elimination of the hematoma. The presentation patterns are best explained by topographic organization of the third nerve fiber within the subarachnoid space. This case suggests that the topographic organization of the third nerve should be considered in diagnosis of oculomotor nerve palsy.