Date post: | 30-Jun-2015 |
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Health & Medicine |
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Unilateral optic neuropathy? - the value of the visual fields
Dr Clare Fraser
History
46 yo man, Fijian-Indian heritage
6 Feb: family doctor with 2 week history myalgia nausea and loss of appetite blurred vision
Diagnosed as viral illness Told to increase his thyroxine dose
8 Feb
Presents to Eye Emergency Department
blurred vision when reading vision “fading in and out” in his left
eye
denies recent viral illness denies current systemic symptoms no headache no pain on eye movement
Background
Past ocular history myopic colour blind
Past medical history Hashimotos thyroiditis thalassaemia trait low Vit D
Medications thyroxine
Background
Family history thalassaemia trait no vision loss
Social history works in office, lots of computer work no cigarettes or alcohol normal balanced diet
8 Feb
RIGHT
6/6
full eye movements
Anterior segment normal
Dilated fundus exam normal
LEFT
6/18 50% red desaturation
no RAPD
Anterior segment normal
Dilated fundus exam normal
HR 69 reg, BP 100/68, temp 36.8C
8 Feb
8 Feb
Resident review no obvious ocular cause ? bitemporal inferior quadrant field
defect CT scan
normal
Referred for routine clinic follow-up “left optic neuritis”
19 Feb (+11 days)
returns to Eye Emergency no longer feels safe to drive
myalgia, arthralgia and nausea returned
no neurological symptoms no headache no pain on eye movement
19 Feb
RIGHT
6/21
full eye movements
Anterior segment normal
Dilated fundus exam normal
LEFT
6/120 no red desaturation
no RAPD
Anterior segment normal
Dilated fundus exam normal
HR 72 reg, BP 105/70, temp 36.7C
19 Feb
Patient didn’t want to wait in emergency for repeat work-up very busy at work
Advised not to drive!
Booked for neuro-ophthalmology clinic 2 days later
21 Feb
Failed to attend neuro-ophthalmology clinic patient contacted really very busy at work
22 Feb (+ 14 days)
Comes back to Eye Emergency vision is so blurred he can’t work
anymore
gradual progression of vision loss
intermittent mild headache loss of appetite difficulty sleeping
22 Feb
RIGHT
6/120
no RAPD
Anterior segment normal
Dilated fundus exam normal
LEFT
Count Fingers at 30cm
no red desaturation
full EOMS, pain in left
Anterior segment normal
Dilated fundus exam ? slight disc hyperaemia
HR 70 reg, BP 100/70, temp 36.7C
22 Feb
22 Feb
Call for a neuro-ophthalmology consult Admit
Blood tests – inflammatory, infective work-up
Chest X-ray Lumbar puncture 1g IV methyprednisolone daily
MRI brain/orbits with gadolinium ordered - outside institution
22 Feb: Neuro-op review (+14 days)
Vision 1/60 right, count fingers left Fields to confrontation
left central scotoma right hemi-field red desaturation
Poor pupil response to light OU 0.3 log-unit left RAPD
Cranial nerves normal Upper and lower limb exam – normal Anterior and posterior segments -
normal
Early results
full blood count – normal renal function – normal liver function – normal ESR 2, CRP 0.5
chest X-ray – no evidence of TB or sarcoid
Lumbar puncture - normal opening pressure and basic constituents
Diagnosis
“Atypical optic neuritis” 46 year old man Fijian-Indian nausea, sleep disturbance
Long lesion suspected left optic nerve intra-cranially extending to left optic tract (right hemifield)
neuromyelitis optica until proven otherwise Ddx: sarcoid
Dilemma
anti-AQP4 (NMO) results = 2 weeks MRI scan can only be done next week
Do you: continue IVMP? move rapidly to plasma exchange? ▪ based on clinical diagnosis of NMO▪ PLEX started within 15-20 days = best outcome
Magana S et al. Beneficial plasma exchange response in central nervous system inflammatory demyelination. Arch Neurol 2011; 68(7): 870-8
24 Feb (+16 days)
2 days IVMP – no change in vision
Transferred to general hospital 5 days plasma exchange 1g IV methylprednisolone continued 5
days
MRI – left optic nerve enhances
MRI – long optic nerve lesion
MRI – chiasm involved also
MRI – left optic tract
MRI – hypothalmic involvement
MRI – cervical spine = normal
2 March (discharge)
RIGHT
6/60
full EOMs
Anterior segment normal
Dilated fundus exam normal
LEFT
6/90
0.3 log-unit RAPD
Anterior segment normal
Dilated fundus exam normal
Oral prednisolone 60mg taper, azathoprine increasing to 150mg
Follow-up
1 week after discharge
repeat MRI brain – reduction in lesion size and intensity
NMO antibody positive
Longer term follow-up
21 March: (+ 6 weeks) VAR 6/18 VAL 6/18
2 May: (+ 3 months) VAR 6/9 VAL 6/9
14 Nov: (+ 9 months) VAR 6/7.5 VAL 6/7.5
Follow-up visual fields
Now
18 months with no relapses Back at work full-time Able to return to driving
Final medication: mycophenolate 500mg BD thyroxine Vit D supplement
Teaching pointsNeuromyelitis optica
Atypical optic neuritis
Patient subgroups MS is rare: African, Asian
30s+ Bilateral – simultaneous or sequential loss Progresses for > 2 weeks Severe pain > 2 weeks since onset Require steroids to induce recovery
Cannot apply the findings of the Optic Neuritis Treatment Trial
NMO- IgG antibody
Useful after first episode of transverse myelitis, severe or recurrent ON
Serum autoantibody Aquaporin-4 (AQP4) One of the major water channel proteins Sensitivity 50-80% (cell-based higher than ELISA)
Specificity 90-100%
Trebst C et al. Update on the diagnosis and treatment of neuromyelitis optica: recommendations of the meuromyelitis optica study group (NEMOS). J Neurol 2013; 261: 1-16.
Neuromyelitis optica
Optic neuritis Transverse myelitis
Within 2 years of each other Plus 2 of:
Brain MRI non diagnostic for MS Spinal cord lesion > 3 vertebral segments Seropositive for NMO-ab (anti-AQP4)
Wingerchuk D et al. Revised diagnostic criteria for neuromyelitis optica. Neurology 2006; 66(10): 1485-9
NMO spectrum
AQP4-IgG positive longitudinally extensive transverse myelitis
AQP4-IgG positive recurrent or bilateral optic neuritis
Wingerchuk D et al. The spectrum of neuromyelitis optica. Lancet Neurol 2007; 6(9):805-15
Management
Poor prognosis without treatment = medical emergency
5 days IV methylprednisolone Plasmapheresis
immediate improvement 50% improvement in 6 months in 78%
1mg/kg oral prednisolone – slow taper Immunosuppression (azathioprine)
Kim S et al. Clinical efficacy of plasmapheresis in patients with neuromyelitis optica spectrum disorder and effects on circulating anti-aquaporin 4 antibody levels. J Clin Neurol 2013;9(1): 36-42
Comparison
Multiple sclerosis ON
Neuromyelitis optica ON
Race Caucasians Asians, Africans
Eye Unilateral Bilateral or sequential
Recovery Spontaneous Poor without steroids
Course of optic neuritis
Less severe Profound vision loss
Neurological Varied CNS signs Transverse myelitis
Overall prognosis Good recovery Poor recovery without Rx
Thank you