10/3/2016

Chiasmal Syndrome

• Online notes – richardtrevino.net • Email me Everything You Always Wanted – [email protected] to Know About • Disclosures But Were Afraid to Ask! – None Rick Trevino, OD, FAAO Rosenberg School of Optometry

Chiasmal Syndrome Chiasmal Syndrome

• Chiasmal syndrome is the constellation of • Causes of chiasmal syndrome include tumor, signs and symptoms associated with lesions inflammation, and ischemia of the optic • Findings suggestive of an etiology other than – Pituitary adenoma is the most common cause pituitary adenoma: – Visual sxs (blur or difficulties with side vision) • 25% of all brain tumors occur in this region – Younger age – 50% are pituitary ademomas – Unilateral optic disk pallor – Visual disturbance is common – RAPD • Patients with chiasmal lesions may present – A complete hemianopic VF defect c/o headache and/or visual disturbances – VF defect greater inferiorly than superiorly

AJO 2004;137:908-913

Incomplete bitemporal Chiasmal Syndrome hemianopic defect greater above than below – highly • Anatomy Review suggestive of pituitary anenoma • All About Pituitary

Pituitary Adenomas • Incomplete Clinical Features of bitemporal Chiasmal Syndrome hemianopia greater below • Clinical Pearls than above – highly suggestive of – Red Flag Warning Signs something other – Chiasmal Work-up than pituitary Something Else adenoma

1 10/3/2016

The is located 10mm immediately below the

T1-weighted T2-weighted coronal MRI sagital MRI

Pituitary Adenoma Pituitary Adenoma

• Benign slow-growing tumor • Nonfunctioning adenomas • Epidemiology – 25% of cases – 10-25% of all brain tumors – Most common cause of chiasmal syndrome – Incidence highest 30-45yo age group – Only non-specific manifestations, such as – No racial or sex difference headache, prior to onset of vision loss • Classification – May lead to hypopituitarism by compression – Hormone producing (75%) or non-functioning of adjacent normal gland – Most common (25%) produce prolactin • Findings include diabetes insipidus, fatigue, – Signs & symptoms determined by hormone weight loss, hypothyroidism, sexual dysfunction secreted, if any

JAOA 1995;66:559-575 JAOA 1995;66:559-575

2 10/3/2016

Pituitary Adenoma Pituitary adenoma compresses the optic chiasm from below • Prolactin-secreting adenomas – 25% of cases, “prolactinoma” – Women: Galactorrhea-amonorrhea syndrome – Men: Impotence, loss of libido, infertility – Women typically seek care earlier and hence the tumor is discovered while still small – Men often wait longer, resulting in more severe clinical manifestations, including vision loss

JAOA 1995;66:559-575

Pituitary Adenoma Pituitary Adenoma

• • Treatment – The most serious, potentially life-threatening – Medical complication of pituitary adenoma • Treatment-of-choice for smaller hormone- – Acute ischemic or hemorrhagic infarction of secreting tumors the adenoma – Surgery – Rare, with estimated incidence of 1.6% of • Treatment for larger non-secreting tumors and pituitary adenomas smaller tumors resistant to medical therapy – Abrupt onset of symptoms and signs including • Endonasal transsphenoidal endoscopic approach headache, nausea and vomiting, visual used in >90% of cases disturbances, oculomotor paresis, confusion and/or coma.

Best Pract Res Clin Endocrinol Metab. 2009;23:677-692

Nasal cavity Sphenoid open

Sella open Adenoma

Intl Ophthalmol Clin. 2016;56:29-39

3 10/3/2016

Operative Tech Otolaryngol. 2011;22:206-214

Chiasmal Syndrome

• Anatomy Review • All About Pituitary Adenomas • Clinical Features of Chiasmal Syndrome • Clinical Pearls – Red Flag Warning Signs – Chiasmal Work-up

Chiasmal Syndrome Visual Loss

SYMPTOMS SIGNS • VA is typically normal in patients with chiasmal lesions • Visual loss • defects • Depression of central acuity is • Headache • Optic disc pallor rare with bitemporal VF defects • and cupping • Anterior chiasmal lesions • Loss of depth • Oculomotor pareses (“junctional ”) are the perception • Nystagmus exception • Endocrine • Cerebrospinal fluid • Apoplexy is associated with dysfunction rhinorrhea acute vision loss J Clin Neurosci 2014;21:735-740

4 10/3/2016

Headache Visual Field Defects

• 50%-70% of patients with pituitary • Perimetry is the most important test for adenoma detecting chiasmal lesions • Often the presenting symptom • Prior to acuity loss, VF defects may be the • May be mild or severe only clinical sign of a chiasmal lesion • HA severity not related to • VF defects occur most often in patients with tumor size non-functioning tumors – May be related to hormonal • Age at presentation is 10yrs older than imbalance caused by tumor patients with functioning tumors – Mean age at presentation: 54yo (non-function)

Arch Neurol 2004;61:721-5. J Clin Neurosci 2014;21:735-740

10%

44% 13%

33% Posterior Compression

Central Compression Visual field defects in 103 consecutive patients Anterior presenting to neurosurgery with pituitary adenoma Compression

J Clin Neurosci 2014;21:735-740

Junctional scotoma of the left eye. This 69yo man presented with c/o vision loss OS x 4 weeks. BVA was 20/25 OD and FC OS. +APD OS. CT scan revealed a pituitary adenoma.

5 10/3/2016

Visual Field Defects

• Bitemporal hemianopia is NOT pathognomonic for chiasmal syndrome • Other conditions that can give rise to bitemporal vision loss – Tilted disc syndrome – Overhanging redundant upper lid tissue – Enlarged blind spots – Bilateral medullation of nasal nerve fibers

JAOA 1995;66:559-575

Tilted disc Tilted disc syndrome syndrome simulating simulating bitemporal bitemporal hemianopia hemianopia

Bitemporal Hemianopia

• The temporal crescents are the only part of the binocular “BHA is exceedingly uncommon in VF that is lost patients with pituitary • A central 110–120° macroadenoma. Bitemporal and remains but there are mixed defects are the most no overlapping VF common abnormal VF findings, they elements were found in only 42.6% of • Lack of fusion lock patients..” decompensates any pre-existing phoria into a tropia Lee IH, Miller NR, Zan E, et al. Visual defects in patients with pituitary adenomas: The myth of . Am J Roentgenol. 2015;205(5):W512-W518. Ophthal Physiol Opt 2014;34:233-242

6 10/3/2016

Absence of fusion lock allows Orthophoria. Orthotropic fixation results in hemifields to slide. mild loss of peripheral vision (temporal crescents) and a When converged at near, there normal percept. is overlap before the target and Left esotropia. blindness behind it. Left esotropia shifts the left nasal field to the right, leaving a vertical strip of central scotoma between the two nasal hemi- fields Left exotropia. Left exotropia shifts the left nasal field to the left, overlapping the right nasal field (crosshatched area), resulting in diplopia. Left hypertropia. Left hypertropia slides the left nasal hemifield upward causing the right image to be perceived as lower. This may be reported as double vision (split diplopia)

Effect of various disease conditions on Titmus Stereo Test Diplopia & Stereopsis

• Intermittent diplopia occurs due to decompensating exophoria and vertical imbalance • Poor depth perception is an important symptom of chiasmal syndrome • Loss of overlapping VF at fixation results in severe loss of stereopsis, even when VF loss is minimal and VA is preserved. • Stereo tests are a simple, easy, and quick screening test for chiasmal disease

Ophthalmology. 2002;109:1692-1702 Ophthalmology. 2002;109:1692-1702

Chiasmal Syndrome Optic Disc

SYMPTOMS SIGNS • Pituitary adenoma is an important cause of non-glaucomatous optic disc cupping • Visual loss • Visual field defects – Compression of the • Headache • Optic disc pallor and chiasm can produce enlargement of the cup • Diplopia and cupping • Chiasmal compression • Oculomotor pareses • Loss of depth preferentially affects the perception • Nystagmus nasal and temporal rim, • Endocrine • Cerebrospinal fluid resulting in a horizontal dysfunction rhinorrhea band of pallor (“bow-tie”)

Arch Ophthalmol. 2010;128:1625-6

7 10/3/2016

Optic Disc

• Chiasmal compression results in RNFL thinning on OCT – Unlike glaucoma, RNFL thinning is fairly uniform in all meridians – Greater loss in the nasal and temporal sectors results in band atrophy – More severe RNFL loss is associated with less VF recovery following tumor excision • Chiasmal lesions do not cause papilledema

J Clin Neurosci. 2015;22:1098-1104

Nasal & temporal RNFL is spared in glaucoma But not by chiasmal disease

There is relative sparing of the nasal and temporal RNFL with glaucomatous but not with chiasmal compression. Ophthalmology. 2014;121:1516-1523

Optic Disc OS OD

• Visual outcome following pituitary adenoma surgery is highly variable – RNFL thickness, duration of symptoms, disc PRESENTATION PRESENTATION pallor, and age influence recovery – Most patients will experience some recovery, and many will experience complete resolution of VF defects – Most of the recovery occurs within the first 3 months following surgery 3 MOS POST-OP

J Clin Neurosci. 2015;22:1098-1104

8 10/3/2016

Chiasmal Syndrome Chiasmal Syndrome

SYMPTOMS SIGNS • Anatomy Review • Visual loss • Visual field defects • All About Pituitary Adenomas • Headache • Optic disc pallor • Diplopia and cupping • Clinical Features of Chiasmal Syndrome • Loss of depth • Oculomotor pareses perception • Nystagmus • Clinical Pearls • Endocrine • Cerebrospinal fluid – Red Flag Warning Signs dysfunction rhinorrhea – Chiasmal Work-up

Red Flags Chiasmal Work-up

• Headaches • Headache history 103 patients >65yo with pituitary • Normal tension adenoma. 33% initially • Confrontation VF glaucoma misdiagnosed • Stereopsis • Unexplained poor visual acuity • Pupils & color vision • Poor depth • Perimetry perception/stereo • Ophthalmoscopy • Intermittent diplopia & OCT • MRI J Clin Neurosci. 2008;15:1091-1095

Headache Confrontation VF

• Specifically inquire about any new or Rapid, simple, yet effective check for gross VF defect unusual headaches • Positive headache history increases risk of pituitary tumor – Regardless of severity or nature of headache • Absence of headache does not rule out tumor Arch Neurol 2004;61:721-5. Neuro-Ophthalmology Diagnosis and Management. 2nd Ed. 2010

9 10/3/2016

Confrontation VF Stereopsis

FCCF testing of patient with left hemianopia • Stereo tests are a simple, easy, and quick screening test for chiasmal disease • Mild, incomplete bitemporal hemianopia can result in loss of stereopsis that is detectable with routine stereo tests • Fail: <6/9

Neuro-Ophthalmology Diagnosis and Management. 2nd Ed. 2010 Ophthalmology. 2002;109:1692-1702

Pupils & Color Vision Perimetry

• An APD suggests a lesion other than • Perimetry is the most important test for pituitary adenoma detecting chiasmal lesions • Color vision is a more sensitive • Inadequate VF assessment is the chief indicator of afferent system damage cause of misdiagnosis of chiasmal than VA lesions – Mild-moderate VA loss with significant color • Standard automated perimetry is the vision loss = optic neuropathy is likely “gold standard” – Color vision preserved and VA is poor = optic neuropathy is unlikely – SAP can find defects missed with FCCF

Am J Ophthalmol 2010;149:1000–1004 Surv Ophthalmol 1982;26:334–6

Ophthalmoscopy & OCT MRI

• Early • Required to confirm diagnosis and plan – ONH appearance and OCT normal despite treatment significant VF defects • Order MRI of optic chiasm with and – Compression impairs function prior to without contrast ganglion cell death (recovery possible) • The exploration protocol is with T1- • Late weighted sagittal sections, then T2- and – Bow-tie pallor (nasal & temporal quadrants) T1-weighted coronal sections with and – Disc cupping without contrast – Diffuse RNFL thinning w/wo band atrophy

Internat Ophthalmol Clin 2016;56:1-27 Diagn Interv Imaging 2013;94:957-971

10 10/3/2016

Indications for MRI 11/2003 Findings that suggest a patient has an intracranial tumor rather than NTG 12/2003 • Younger age (<50 yrs) • Reduced VA (< 20/40) • Vertically 4/2006 aligned VF defects • Neuroretinal rim Example of “vertically aligned” VF pallor defect Ophthalmology 1998;105:1866-1874

Key Points

• Chiasmal syndrome is a subtle, easily missed condition • Headache and BV complaints are common Thank you! • Be suspicious of all NTG suspects • Stereopsis is a useful screening test • Threshold perimetry is the test of choice for detecting chiasmal syndrome

11