Poster
# 82
Poster |
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6th Internet World Congress for Biomedical Sciences |
Jorge Burneo de las Casas(1), Andrew Chang(2)
(1)Henry Ford Health System - detroit. United States
(2)Affiliated Comm. Medical Center - Willmar. United States
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[Radiology & Nuclear Medicine] |
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[Neurology] |
See-saw nystagmus (SSN) is an uncommon disorder, characterized by a rotatory nystagmus, with the eyes moving conjugately clockwise and then counterclockwise. The torsional movements are accompanied by disconjugate vertical oscillations. The intorting eye elevates while the opposite eye, which is extorting, falls (1). Acquired SSN most often occurs with parasellar or chiasmal mass lesions, but has been associated with cerebrovascular disease in the brainstem, head injury (2), Arnold-Chiari malformation (3), Syringomyelia, Syringobulbia, Multiple Sclerosis (4) Septo-optic dysplasia (5). Thus far, there have been no reports of an association with Neurosarcoidosis (NS). We present a patient with see-saw nystagmus and NS.
A 30 year-old woman, presented with blurred vision for three weeks, associated with difficulty walking and also intermittent diplopia. Her past medical history was pertinent for Diabetes Mellitus, Hypertension and Panic attacks. On exam, she was alert and oriented. Neuro-ophtalmological exam showed florid see-saw nystagmus, preserved visual acuity of 20/20,normal fundoscopic exam, and full visual fields. On motor exam the tone was normal, and no weakness was noted, although patient had a tremor involving both hands and feet. Mild dysmetria was noted on finger-to-nose and heel-to-shin. Her gait was ataxic. Initial CT scan of the head revealed hydrocephalus (fig. 1) and subsequent MRI of the brain with gadolinium showed prominent ventricular cisterns in the absence of meningeal enhancement (fig. 2). A lumbar puncture showed elevated opening pressure with a CSF analysis showing decreased glucose and elevated protein as well as lymphocytic pleocytosis, with negative tests for infections. CT scan of the chest showed symmetrical hilar and mediastinal lymphadenopathy suggestive of sarcoidosis. The bronchial biopsy showed granulomas. The patient was started on steroid therapy. However, with no improvement in the hydrocephalus, a ventriculo-peritoneal shunt was placed(fig.3). Three months post shunt placement, the patient remains asymptomatic.
The pathophysiology of SSN remains unclear. Its association with bitemporal homonymous hemianopsia in patients with parasellar and chiasmal lesions initially led to the speculation that SSN was related to a disturbance in the visual input. Subsequent reports of SSN in patients with chiasmal and brainstem lesions in the absence of significant visual deficits made the previous concept not true. (4,6).
The instertitial nucleus of Cajal (INC), adjacent to the medial longitudinal fasciculus in the midbrain tegmentum, has been frequently implicated in the pathogenesis of SSN. Fibers from the INC project to the oculomotor and trochlear nerves, vestibular nuclei and spinal cord. A disturbance in the INC itself or in its projections may contribute to the mechanism underlying SSN.(4).
With SSN ocurring in association with NS as seen in our patient, we postulate that granulomatous inflammation of the INC and/or in the accesory optic tract, a pathway of nerve fibers traversing the optic chiasm and the inferior olivary nucleus, may play a significant role in the development of SSN. Hydrocephalus alone has not been reported with SSN.
Acquired SSN most often occurs with parasellar or chiasmal mass lesions, but has been associated with brainstem vascular disease, head injury, Arnold-Chiari malformation, syringomyelia, syringobulbia, multiple sclerosis, and septo-optic dysplasia. Neurosarcoidosis has not been previously described in association with SSN, but may be a useful differential consideration in its evaluation and treatment.
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[Radiology & Nuclear Medicine] |
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[Neurology] |
