Archives for December 2017

Cardinal features of superior oblique myokymia: An infrared oculography study

Recommended Reading

Question: What are the cardinal features of superior oblique myokymia?
Answer: There are 6 cardinal features of eye movement abnormality in superior oblique myokymia including:
1) involuntary intorsion and torsional oscillations;
2) episodic events lasting seconds;
3) worsening with infraduction and abduction positions that require activation of the superior oblique, and improvement with supraduction and adduction positions where the superior oblique is not activated;
4) overshooting of saccades on infraduction;
5) extorsion and diminished oscillations that were unmasked upon removal of a visual target, consistent with underlying weakness; and
6) improvement with membrane stabilizers used to treat neuropathic conditions. These features localized the lesion to the trochlear nerve, fascicle, or nucleus but not to the superior oblique muscle or neuromuscular junction.

https://www.youtube.com/watch?v=EXpBXrva77U

Neuro-ophthalmology Questions of the Week: Papilledema

Questions:
1. What visual symptoms may patients with papilledema report?
2. When is central visual acuity loss experienced in papilledema, early or late?
3. What type of visual field defect is found initially with papilledema?
4. What type of visual field loss is experienced in long-standing papilledema?
5. Can visual loss from papilledema happen with any cause of papilledema?
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Neuro-ophthalmology Questions of the Week: Evaluation of Disc Edema

Questions:
1. Once optic disc edema is confirmed, what should be determined?
2. In anterior optic neuropathy with disc edema is visual acuity usually decreased?
3. In papilledema is visual acuity usually decreased?
4. In anterior optic neuropathy with disc edema is color vision usually decreased?
5. In papilledema is color vision usually decreased?
6. What are the usual characteristics of visual field defects in anterior optic neuropathy with disc edema?
7. What are the usual characteristics of visual field defects in papilledema?
8. Is anterior optic neuropathy with disc edema usually unilateral?
9. Is papilledema usually unilateral?
10. What findings are often associated with papilledema?
11. Does the absence of disc edema rule out raised intracranial pressure in a patient presenting with headache?
12. Does the absence of spontaneous retinal venous pulsations at the disc rule-out elevated intracranial pressure?
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Neuro-ophthalmology Question of the Week: Differentiating Disc Edema from Pseudoedema

Question:
Which of the following are indicative of pseudoedema of the optic disc rather than disc edema?
1. Sharp disc margins
2. Obscured vessels
3. Venous dilation and tortuosity
4. Peripapillary hemorrhages and exudates
5. Leakage on fluorescein angiogram
6. Anomalous retinal vasculature (arterial branching)
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