Optic Chiasm, Parasellar Region, and Pituitary Fossa

The Impact of Optic Nerve Disorders on Sleep Wake

“…pRGCs are able to detect light, but are non-image forming, and form functional pathways involved in regulation of circadian rhythm, sleep and alertness, and pupillary responses. pRGCs conduct this photic information along the optic nerves, which are components of the RHT, and relay this to multiple intracranial nuclei, including the SCN (38,(120)(121)(122)(123)(124)(125)(126).…”

“…Multiple meningiomas and familial meningiomas may be associated with NF1. Examination may reveal bitemporal and incongruous VFD and OA, with some patterns of optic nerve cupping and altitudinal VFD being mistaken for glaucomatous optic neuropathy (121,397).…”

“…CP are embryological epithelial tumours of the sellar and suprasellar region formed in the craniopharyngeal duct from the vestigial residue of Rathke's pouch between the anterior and posterior pituitary (121,398). CP are relatively rare, comprising 2-4% of intracranial neoplasms, with incidence of 1.3 cases per million person years (399).…”

“…A gradual reduction of monocular or binocular vision is common, but acute worsening or fluctuation in vision may resemble an ON, due to swelling of RGC axons and surrounding structures, progressing to RGC apoptosis and OA over time. The axons of RGCs lie in the optic chiasm and long-term chiasm compression can lead to defective nerve fibre layer function, with poorer visual recovery post-resection(121). Intracranial causes of compressive optic neuropathies include infectious, inflammatory, vascular, traumatic, neoplastic and bony tumours(385); in this section I will focus on primary lesions such as PA, meningiomas and craniopharyngiomas (CP).2.10.7(a)(i) Pituitary AdenomasPA are slow-growing benign growths of the pituitary gland and comprise 12-15% of symptomatic intracranial neoplasms, with incidence increasing with age.…”

“…They are present in approximately 16.7% of the population, and some can be invasive with progression to the optic chiasm, which lies 10mm above the pituitary gland. Sudden enlargement of the adenoma can be precipitated by haemorrhage or infarction (pituitary apoplexy), resulting in acute visual loss, ophthalmoplegia, headache, and facial dysaesthesiae(121). Many adenomas, however, are asymptomatic and are detected incidentally on neuroimaging or at postmortem(386).…”