Flashcards in CN LANGE - Neuro-Ophthalmic Disorders III Deck (105):
Painless, passive, typically bilateral disk swelling associated with increased ICP.
Papilledema - What may precede frank disk swelling?
Transient visual obscurations.
Associated non specific symptoms of raised ICP include:
4. Diplopia - mainly from VI palsy.
How much time does papilledema require to resolve after restoration of ICP?
2 to 3 months.
Papilledema - Fundoscopic examination reveals (in order of onset):
1. Blurring of the nerve fiber layer.
2. Absence of venous pulsations.
3. Hemorrhages in the nerve fiber layer.
4. Elevation of the disk surface with blurring of the margins.
5. Disk hyperemia.
Absence of venous pulsations - Signify ICP greater than ...?
Papilledema requires urgent evaluation to search for ...?
An intracranial mass + to exclude PAPILLITIS from:
1. Meningeal carcinoma.
--> Produce similar ophthalmoscopic appearance.
A diagnosis of idiopathic intracranial HTN (pseudotumor cerebri) is established by ...?
EXCLUSION when CSF pressure is elevated BUT an intracranial mass lesion + other disorders associated with intracranial HTN are EXCLUDED (by the history, CT/MRI + meningitis is excluded by CSF examination).
MCC of intracranial HTN?
Idiopathic intracranial HTN.
Although pseudotumor cerebri is usually self-limited, prolonged elevation of intracranial pressure + papilledema can lead to ...?
Permanent visual loss.
Less common causes of papilledema:
1. Congenital cyanotic heart disease.
2. Disorders associated with incr. CSF protein content --> Spinal cord tumor + Guillain-Barre syndrome.
Chiasmal lesions - The major lesions are tumors, especially those of pituitary origin, which can be associated with ...?
Other less common causes of chiasmal lesions:
3. Berry aneurysms.
The classic pattern of chiasmal visual deficits is ...?
Chiasmal visual loss is ... in onset.
GRADUAL in onset - EXCEPT with pituitary apoplexy due to acute intrapituitary hemorrhage.
Headache, endocrine abnormalities, and occasionally blurred or double vision may occur in patients with an ...?
Enlarged sella turcica --> In whom NEITHER TUMOR NOR INCR. ICP is found.
Patients with an enlarged sella turcica are said to have ... syndrome.
Empty sella syndrome.
Empty sella syndrome is more common in ...?
WOMEN - Between 4th-7th decades of life.
Treatment of empty sella syndrome:
Retrochiasmal lesions - Lesions of the optic tract + lateral geniculate body are usually due to ...?
Lesions of the optic tract and lateral geniculate body - The result is usually:
A noncongruous homonymous hemianopia.
--> The field defect is NOT THE SAME in the 2 eyes.
Lesions of the optic tract and lateral geniculate body - Associated with ...?
HEMISENSORY LOSS - If thalamic lesions.
Lesions of the optic radiations - Produce a ...?
CONGRUOUS (bilaterally symmetric) homonymous hemianopia.
Lesions of the optic radiations - Visual acuity is ... in the unaffected portion of the field.
Lesions of the optic radiations - Lesions in the temporal lobe:
The field defect is denser SUPERIORLY than inferiorly, resulting in a superior quadrantanopia ("pie in the sky" deficit).
Lesions of the optic radiations - Lesions in the temporal lobe - MCC:
Lesions of the optic radiation - Parietal lobe - May be due to ...?
2. Vascular disease.
Lesions of the optic radiation - Parietal lobe - Associated with:
Contralateral weakness + sensory loss.
Lesions of the optic radiation - Parietal lobe - A gaze preference ...?
Common in the ACUTE phase, with the eyes conjugately deviated to the side of the parietal lesion.
Lesions of the optic radiation - Parietal lobe - Visual field abnormality is ...?
1. Either complete homonymous hemianopia.
2. Or INFERIOR quadrantanopia.
Lesion of the optic radiation - Parietal lobe - The optokinetic response to a visual stimulus moved toward the side of the lesion is ...?
IMPAIRED - Not the case with pure temporal or occipital lobe lesions!
Lesions in the occipital cortex - Produce:
Homonymous hemianopia affecting the contralateral visual field.
--> Patient may be UNAWARE of the visual deficit.
Lesions of the occipital cortex - Why sparing of the macula?
Because the region of the occipital cortex in which the macula is represented is often supplied by branches of BOTH the PCA and the MCA, visual field abnormalities caused by vascular lesions in the occipital lobe may show SPARING OF THE MACULAR REGION.
Lesion of the occipital cortex - Why sparing of the macula - 2nd explanation?
May also result from BILATERAL cortical representation of the macular region of the visual field.
MCC of visual impairment in the occipital lobe is ...?
Lesions of the occipital cortex - Less common causes:
1. Occipital lobe AV malformations.
2. Vertebral angiography (!).
3. Watershed infarction after cardiac arrest.
Tumors and occipital lobe AV malformations are often associated with ...?
Unformed visual HALLUCINATIONS that are typically UNILATERAL + STATIONARY/MOVING + BRIEF/FLICKERING + COLORED/NOT COLORED.
Bilateral occipital lobe involvement produces ...?
Bilateral occipital lobe involvement - Pupillary reactions:
Bilateral occipital lobe involvement - Bilateral macular sparing may preserve ...?
Central (tunnel) vision.
Bilateral occipital lobe involvement - With more extensive lesions, ...?
DENIAL OF BLINDNESS may occur = ANTON SYNDROME.
Disorders of eye movement - Gaze palsies - Lesions of the ...?
CORTEX or BRAINSTEM --> May impair conjugate (yoked) movement of the eyes --> Gaze disorders.
In milder gaze palsies what is affected?
of the FAST eye movements.
Gaze palsies - 3 categories of lesions:
1. Hemispheric lesions.
2. Midbrain lesions.
3. Pontine lesions.
Gaze palsies - Hemispheric lesions:
Acute hemispheric lesions produce tonic deviation of BOTH eyes TOWARD the side of the lesion + AWAY from the side of the hemiparesis.
Gaze palsies - Hemispheric lesions - This gaze deviation may last for ...?
DAYS in alert patients (somewhat longer in COMATOSE patients).
Gaze palsies - Hemispheric lesions - Seizure discharges involving the frontal gaze centers can also produce ...?
GAZE DEVIATION by driving the eyes AWAY from the discharging focus.
Gaze palsies - Hemispheric lesions - When the IPSILATERAL MOTOR CORTEX is also involved, producing focal motor seizures, the patient gazes ...?
TOWARD THE SIDE OF THE SEIZURE-INDUCED motor activity.
Gaze palsies - Midbrain lesions - Lesions of the DORSAL midbrain affect the center responsible for ...?
VOLUNTARY UPWARD GAZE --> Upgaze paralysis.
Gaze palsies - Midbrain lesions - Parinaud syndrome:
All or some of the features of Parinaud syndrome may occur:
1. Preserved reflex vertical eye movements with the doll's head maneuver or Bell phenomenon.
2. Nystagmus - especially on DOWNWARD gaze and typically associated with retraction of the eyes.
3. Paralysis of accommodation.
4. Midsized pupils.
5. Light-near dissociation.
Elevation of the eye upon eyelid closure.
Gaze palsies - Pontine lesions - The pontine gaze center is ...?
In the region of PPRF.
Brainstem lesions at the level of the pontine gaze centers produce ...?
Disorders of CONJUGATE HORIZONTAL GAZE, but UNLIKE HEMISPHERIC lesions --> Cause eye deviation TOWARD, rather than away from, the side of HEMIPARESIS.
Why do brainstem lesions at the level of the pontine gaze centers produce disorders of conjugate horizontal gaze, BUT, UNLIKE hemispheric lesions, cause eye deviation TOWARD the side of the hemiparesis?
This occurs because the corticobulbar pathways that regulate gaze have crossed at this level, but the descending motor (pyramidal) pathways have not.
Brainstem gaze palsies are characteristically far more RESISTANT to ...?
Attempts to move the eyes (via the doll's head maneuver or caloric stimulation) than are hemispheric gaze pareses.
In addition, gaze palsies from brainstem lesions are commonly associated with ...?
VI nerve palsies because the nucleus of the nerve is involved.
Internuclear ophthalmoplegia (INO) results from ...?
Lesions of the MLF between the mid-pons and the III nerve nucleus that DISCONNECT the VI nucleus from the contralateral III nucleus.
The site of INO is named according to the ...?
Side on which III nerve function is impaired.
INO results in a characteristic ...?
Disconjugate gaze with impaired adduction + Nystagmus of the ABDUCTING EYE.
An INO usually implies ...?
INTRINSIC BRAINSTEM DISEASE.
INO - MCC especially in young adults and patients with BILATERAL involvement:
INO - MCC in OLDER patients and those with UNILATERAL involvement:
INO etiology - Stroke and MS encompass at least ...?
80% of all cases.
INO - Rarer causes:
1. Brainstem encephalitis.
2. Intrinsic brainstem tumors.
4. Sedative drug intoxication.
5. Wernicke encephalopathy.
INO - What must be ruled out?
Myasthenia gravis - Can mimic lesion of the MLF.
Binocular disorders - 3 main categories:
2. Chiasmal lesions.
3. Retrochiasmal lesions.
Ocular nerve palsies - III nerve lesions - 4 Levels:
2. Subarachnoid space.
3. Cavernous sinus.
III nerve palsy - Brainstem - How do we localize the lesion in the brainstem?
1. Associated CONTRALATERAL hemiplegia = WEBER SYNDROME.
2. Associated CONTRALATERAL ataxia = BENEDIKT SYNDROME.
--> The 2 MC vascular syndromes.
III nerve palsy - Subarachnoid space - How do we localize the lesion?
Compressive lesions in the subarachnoid space typically impair the pupillary light reflex --> This reflex tends to be spared with ischemic (eg diabetic) lesions.
III nerve lesions - Subarachnoid space - Common causes:
As the III nerve exits the brainstem in the INTERPEDUNCULAR space --> Susceptible to injury from:
2. PCA aneurysms.
III nerve lesion - Cavernous sinus - How do we localize the lesion?
1. Usually involved with other nerves (IV, VI, V1, V2).
2. Horner syndrome may occur.
3. Tend to produce PARTIAL DEFICITS that may or may not spare the pupil.
III nerve lesions - Orbit - How do we localize the lesion?
1. Associated with II nerve involvement + EXOPHTHALMOS.
2. However --> May be clinically INDISTINGUISHABLE from cavernous sinus lesions --> Need for CT/MRI.
IV nerve lesions - Common cause of ISOLATED IV nerve palsy?
Head trauma - Often minor.
What must be excluded in a patient with IV nerve palsy and NO TRAUMA?
3. Thyroid disease.
4. Orbital mass lesions.
--> If ALL excluded --> Observation is the appropriate clinical approach.
VI nerve lesions - In elderly patients think of:
2. Vascular disease.
4. DETERMINE ESR --> EXCLUDE rare presentation of GIANT CELL ARTERITIS.
VI nerve lesion - When imaging of the base of the skull is indicated?
To exclude NASOPHARYNGEAL CARCINOMA or other tumors.
When are we allowed to follow VI nerve palsy conservatively?
In PAINLESS VI palsy + Studies are NORMAL + ABSENT neurologic symptoms + NORMAL ICP.
What to give in PAINFUL VI palsy?
A trial of prednisone (60mg/d ORALLY for 5d) --> If dramatic relief --> Support a tentative diagnosis of IDIOPATHIC inflammation of the superior orbital fissure (SUPERIOR ORBITAL FISSURE SYNDROME) or cavernous sinus (TOLOSA-HUNT SYNDROME).
VI nerve lesions - Persistent pain DESPITE treatment with steroids should prompt investigation of the cavernous sinus by ...?
CT/MRI + In some cases --> Angiography.
VI nerve lesions - The presence of a concurrent HORNER syndrome localizes the underlying lesion to the ...?
Diabetic ophthalmoplegias - What may occur regarding III, IV, VI nerves?
An ISOLATED III, IV, or VI nerve lesion may occur in patients with DM - Non invasive procedures reveal NO ABNORMALITY.
What is the special feature of diabetic III nerve lesions?
Why is there pupillary sparing in diabetic III nerve lesions?
Attributed to infarction of the central portion of the nerve with sparing of the more peripherally situated fibers that mediate pupillary constriction.
Other pupil-sparing III palsies can also be seen with ...?
1. Compressive - Inflammatory - Infiltrative lesions.
that affect the III NUCLEUS or FASCICLE within the midbrain.
In known diabetics, painful ophthalmoplegia with exophthalmos + met. acidosis requires urgent attention to determine the possibility of ...?
FUNGAL infection in the paranasal sinus, orbit, or cavernous sinus by MUCORMYCOSIS.
Painful ophthalmoplegias - Dysfunction of one or more of the ocular motor nerves with accompanying pain may be produced ...?
By lesions ANYWHERE from the posterior fossa to the orbit.
Painful ophthalmoplegias - What should we evaluate?
1. Careful documentation of the clinical course.
2. Inspection, and palpation of the globe for PROPTOSIS (localizing the process to the orbit or anterior cavernous sinus).
3. Auscultation over the globe to detect a bruit (carotid artery-cavernous sinus fistula or another vascular anomaly).
4. Evaluation for diabetes.
Painful ophthalmoplegias - Useful lab studies:
1. Blood glucose.
2. Orbital CT/MRI.
3. Carotid arteriography.
4. Orbital venography.
Etiology of painful ophthalmoplegia - Orbit:
1. Orbital pseudotumor.
3. Tumor (primary/metastatic).
4. Infection (bacterial/fungal).
Etiology of painful ophthalmoplegia - Cavernous sinus:
1. Tolosa-Hunt syndrome (idiopathic granulomatous inflammation).
2. Tumor (primary/metastatic).
3. Carotid artery-cavernous sinus fistula or thrombosis.
Etiology of painful ophthalmoplegia - Sella and posterior fossa:
1. Pituitary tumor or apoplexy.
3. Metastatic tumor.
Etiology of painful ophthalmoplegia - Other:
3. Giant cell arteritis.
PainLESS syndromes that spare pupillary function + Usually BILATERAL.
Ocular myopathies - MCC:
Hyperthyroidism - A cause of double vision beginning in midlife or later.
--> Many patients are otherwise clinically euthyroid at the time of diagnosis.
Ocular myopathy due to hyperthyroidism - What is the MC symptom:
Double vision on attempted elevation of the globe.
Ocular myopathy due to hyperthyroidism - Diagnosis:
Can be confirmed by the FORCED DUCTION TEST - Detects mechanical resistance to forced movement of the anesthetized globe in the orbit.
Ocular myopathy due to hyperthyroidism is usually ...?
Progressive external ophthalmoplegias:
A group of syndromes characterized by slowly progressive, symmetric impairment of ocular movement that cannot be overcome by caloric stimulation.
Progressive external ophthalmoplegias - Pupillary function:
Spared - No pain.
Progressive external ophthalmoplegias - Ptosis:
May be prominent.
Progressive external ophthalmoplegias - This clinical picture may be produced by ...?
Ocular or oculocephalic muscular dystrophy.
Progressive external ophthalmoplegias associated with myotonic contraction on percussion of muscle groups (classically, the thenar group in the palm) suggests the diagnosis of ...?
Kearns-Sayre-Daroff syndrome (deletions in the mt DNA):
Progressive external ophthalmoplegia accompanied by:
1. Pigmentary degeneration of the retina.
2. Cardiac conduction defects.
3. Cerebellar ataxia.
4. UP CSF protein levels.
Kearns-Sayre-Daroff syndrome - Muscle biopsy shows:
RAGGEG RED FIBERS = Presence of abnormal mt.