Faculty Bibliography

OBJECTIVE:Pituitary carcinoma is a rare tumor, defined as a tumor of adenohypophyseal cells with systemic or craniospinal metastasis. We present a case of a growth hormone (GH)-secreting pituitary carcinoma with a review of literature to better characterize this disease. DESIGN:Case report and literature review of 25 cases of GH-secreting pituitary carcinomas RESULTS: The age of diagnosis of GH-secreting carcinomas ranged 24-69 years old with a mean age of 44.4 with 52% of cases present in females. Mean latency period between diagnosis of acromegaly and transition to pituitary carcinoma was 11.4 years with mean survival being 3.4 years. CONCLUSION:Growth hormone (GH)-secreting pituitary carcinomas are rare and hard to distinguish from aggressive pituitary adenomas. From review of literature, treatment options include debulking surgery, radiotherapy, or chemotherapy with dismal outcomes. There are no diagnostic markers or features which can predict metastatic progression of these tumors. Future studies with genomic landscapes and relevant tumor markers are needed to identify pituitary tumors most likely to metastasize.

A 73-year-old woman with 3 years of monocular visual distortion and progressive binocular diplopia. She was found to have a comitant left hypertropia due to an epiretinal membrane causing inferior foveal drag. Displacement of the fovea from an epiretinal membrane is a likely under-recognized cause ocular cause of a comitant binocular diplopia.

The authors describe the case of a 19-year-old female who suffered posttraumatic emphysema of the optic nerve sheath. She suffered massive head trauma requiring emergent neurosurgery and was incidentally found to have air in her optic nerve sheath on CT scan. At 6 weeks follow up, her visual acuity (20/25 uncorrected) and color perception in the affected eye were excellent. Her examination was notable for an afferent pupillary defect, mild disc pallor, and optic nerve atrophy on optical coherence tomography. This is a case of a patient with posttraumatic optic nerve sheath emphysema who recovered excellent visual function and received follow-up ophthalmic imaging.

While cerebral amyloid angiopathy is a common cause of lobar hemorrhage, rarely it may be associated with an inflammatory response, thought to be incited by amyloid deposits. We report a 73-year-old woman with an extensive cancer history who presented with tumor-like lesions and symptoms of homonymous hemianopia and prosopagnosia. Found to have cerebral amyloid angiopathy-related inflammation proven by brain biopsy, she was treated successfully with immunosuppression.

OBJECT Automated eye movement tracking may provide clues to nervous system function at many levels. Spatial calibration of the eye tracking device requires the subject to have relatively intact ocular motility that implies function of cranial nerves (CNs) III (oculomotor), IV (trochlear), and VI (abducent) and their associated nuclei, along with the multiple regions of the brain imparting cognition and volition. The authors have developed a technique for eye tracking that uses temporal rather than spatial calibration, enabling detection of impaired ability to move the pupil relative to normal (neurologically healthy) control volunteers. This work was performed to demonstrate that this technique may detect CN palsies related to brain compression and to provide insight into how the technique may be of value for evaluating neuropathological conditions associated with CN palsy, such as hydrocephalus or acute mass effect. METHODS The authors recorded subjects' eye movements by using an Eyelink 1000 eye tracker sampling at 500 Hz over 200 seconds while the subject viewed a music video playing inside an aperture on a computer monitor. The aperture moved in a rectangular pattern over a fixed time period. This technique was used to assess ocular motility in 157 neurologically healthy control subjects and 12 patients with either clinical CN III or VI palsy confirmed by neuro-ophthalmological examination, or surgically treatable pathological conditions potentially impacting these nerves. The authors compared the ratio of vertical to horizontal eye movement (height/width defined as aspect ratio) in normal and test subjects. RESULTS In 157 normal controls, the aspect ratio (height/width) for the left eye had a mean value +/- SD of 1.0117 +/- 0.0706. For the right eye, the aspect ratio had a mean of 1.0077 +/- 0.0679 in these 157 subjects. There was no difference between sexes or ages. A patient with known CN VI palsy had a significantly increased aspect ratio (1.39), whereas 2 patients with known CN III palsy had significantly decreased ratios of 0.19 and 0.06, respectively. Three patients with surgically treatable pathological conditions impacting CN VI, such as infratentorial mass effect or hydrocephalus, had significantly increased ratios (1.84, 1.44, and 1.34, respectively) relative to normal controls, and 6 patients with supratentorial mass effect had significantly decreased ratios (0.27, 0.53, 0.62, 0.45, 0.49, and 0.41, respectively). These alterations in eye tracking all reverted to normal ranges after surgical treatment of underlying pathological conditions in these 9 neurosurgical cases. CONCLUSIONS This proof of concept series of cases suggests that the use of eye tracking to detect CN palsy while the patient watches television or its equivalent represents a new capacity for this technology. It may provide a new tool for the assessment of multiple CNS functions that can potentially be useful in the assessment of awake patients with elevated intracranial pressure from hydrocephalus or trauma.

Purpose: We have developed a novel method for quantitation of both horizontal and vertical eye movement conjugacy that is performed by comparing the position of the pupils over time while a subject is eye tracked watching a video playing in a moving aperture or on a full screen monitor. The purpose of this work is to compare the horizontal, vertical and total conjugacy of eye movements with these different stimuli. Methods: 57 normal control subjects who denied neurologic or ophthalmic dysfunction were binocularly eye tracked with a camera placed at a fixed distance while watching a music video playing continuously in an aperture moving in a rectangular configuration. Ten of these subjects also watched a video moving in a square pattern within an aperture. For both the square and rectangle pattern of viewing, the aperture was approximately 1/9 of the screen size of a 17 "diameter monitor. 17 of the original 57 subjects viewed a 40 second video playing on the same full screen 17" diameter computer monitor. Right and left eye positions were compared to assess conjugacy of eye movement in Cartesian space relative to time. All data were analyzed using XLSTAT version 2012.6.02 (Addinsoft SARL, Paris, France) and MedCalc version 12.6.1 (MedCalc Software, Ostend, Belgium). A p-value of < 0.05 was deemed as statistically significant. We compared eye-tracking parameters among the groups using the Kruskal-Wallis test. Results: Normal subjects demonstrated conjugate eye movement that was not impacted by age or sex. Subjects demonstrated significantly increased total conjugacy of eye movement when viewing the smaller moving aperture relative to the full screen. There was no difference in total, horizontal, or vertical conjugacy of eye movement between the square and rectangular patterns of movement. Horizontal eye movement was significantly more conjugate than vertical eye movement regardless of whether the eyes were following an aperture moving in a square or a rectangle. Conclusions: Normal control subjects have eye movements that are more conjugate when viewing a video playing in a small aperture versus on a larger screen, and in the horizontal versus vertical plane, as assessed by our algorithm. Since a disconjugate gaze may result from intracranial pathology the algorithm we have developed may be useful for automatable assessment and monitoring of patients with neurologic dysfunction