PGS.TS Cao Phi Phong

2017

Neuro-ophthalmology- nội trú thần kinh

ảnh hưởng hệ thống thị giác hướng tâm

(primarily vision)

ảnh hưởng hệ thống thị giác ly tâm

(primarily anisocoria and extraocular motility).

định khu là khẩn cấp

+ retina,

+ optic nerve,

+ optic chiasm, optic tract, visual radiations,

+ visual cortex.

Rối loạn đường thị giác hướng tâm (Afferent Visual System Disorder)

Ca lâm sàng

Bệnh nhân nữ 41 tuổi, nội trợ

Bệnh xảy ra đột ngột, sáng ngủ dậy mờ mắt (p ),

nhìn thấy bóng. Thị lực xấu dần

Tiền sử: sốt bại liệt từ nhỏ, cao huyết áp > 1 năm

không uống thuốc thường xuyên, ly dị chồng và có

1 con 16 tuổi

Thăm khám

M:84l/p, HA:130/70mmHg

Đồng tử mắt p =3mm, pxas chậm, mắt t =2,5mm, pxas tốt, px đồng cảm còn. Gai thị p bờ gai xoá mờ, xung huyết, tĩnh mạch dãn lớn, xuất huyết, xuất tiết, không nhìn thấy động mạch

CTM BC:9090(N:57,9%,L:33,6%,E:3,95%) HC:5.210.000 TC:284.000

Sinh hoá (đường, bun, creatinine, ion đồ) bình thường, cholesterol 179mg/dl, HDL:47mg/dl, LDL:109mg/dl, triglyceride: 257mg/dl

ECG,ECHO tim, bụng bình thường, x quang phổi: quai đm chủ rộng, dày màng phổi vùng đỉnh 2 bên

Chức năng đông máu bình thường

Vấn đề

1. Vị trí tổn thương?

2. Các xét nghiệm cần làm?

Giảm hay mất thị lực cấp (Acute Visual Deterioration or Loss)

Mất thị lực một mắt(Monocular Visual Loss) Retinopathy, Optic Neuropathy

Bệnh lý mắt

+ Acute Glaucoma + Vitreous Hemorrhage + Retinal Detachment + Iritis + Chorioretinitis

Mất thị lực 2 mắt (Binocular Visual Loss)

Papilledema refers to edema of the optic nerve head by

various causes.

(The current theory about the underlying mechanism of all forms of papilledema relates to axoplasmic transport or to the flow of cytoplasmic material along the nerves resulting in swelling of the axon.)

Papilledema: four causes (1) increased intracranial pressure, (2) intraorbital disease, (3) intraocular disease, (4) systemic disease affecting the eyes.

optic nerve hay retinal disorder?

Chẩn đoán phân biệt mất thị lực đột ngột

Phần lớn bn mất thị lực cấp phân 2 nhóm (1) optic nerve disease, thường nhất là ON

hay ischemic optic neuropathy; (2) retinal disease, thường arterial occlusion.

Ocular ischemic syndromes

1 Central retinal artery occlusion (CRAO). 2 Branch retinal artery occlusion (BRAO). 3 Ischemia of the optic nerve (anterior

ischemic optic neuropathy or AION). 4. Retinal vein occlusions: branch (BRVO), or

central vein occlusions (CRVO). BRVO involves one of the branch retinal veins

Chẩn đoán

1. Fluorescein angiography is helpful to delineate the hemodynamic changes that occur in the retinal vasculature

2. Angiography: vein is not occluded completely, but the venous return is slow.

- Approximately 50% recover good visual acuity - 2 complications may lead to reduced visual acuity a) macular edema, more than 50% of patients, b) retinal neovascularization

ánh sáng qua võng mạc đến quang thụ thể (photoreceptors

(rods and cones) nằm trên retinal pigment epithelium

(outermost and most posterior layer of the retina).

photoreceptors chuyển đổi ánh sáng thành tín hiệu điện

(electrical signals) đến tế bào hạch (ganglion cells (in the inner

retina) thông qua tế bào lưỡng cực (bipolar cells).

tế bào ngang và không sợi nhánh (Horizontal and amacrine)

điều chỉnh nơ-ron trung gian võng mạc

sợi trục tb hạch tiếp hợp hạch gối ngoài (geniculate ganglion)

Phối hợp carotid arteriosclerosis, giant cell arteritis, và

vasculitides.

Symptoms and Signs

■ Mất thị lực đột ngột một bên không đau, thường mù một

mắt thoáng qua (amaurosis fugax).

■ Macular “cherry red spot” and retinal whitening; retinal

veins normal, but arteries very attenuated and may show

“boxcarring” with intermittent segmental filling of arteries.

Tắc động mạch võng mạc trung tâm

(Central Retinal Artery Occlusion)

Triệu chứng Sudden unilateral painless (usually profound) visual loss, often preceded by transient monocular blindness (amaurosis fugax).

Macular "cherry red spot" and retinal pallor; retinal veins normal, but arteries very attenuated

Ñoät ngoät(thò löïc, thò tröôøng), ñau khoâng ñieån hình

Chaån ñoaùn soi ñaùy maét

Sau nhieàu ngaøy cherry-red spot bieán maát, teo gai nguyeân phaùt

CRAO : chẩn đoán xác định bởi ophthalmoscopy:

+ Partial or complete arrest of retinal circulation.

+ Cardinal signs: - attenuated retinal arteries and veins (very early only),

- a cloudy whitening of the retina (ie, edema) with the consequent cherry-red spot in the macula in a patient who has lost vision in one eye.

+ nếu tắc kéo dài trên 1 giờ, võng mạc nhồi máu mất bù

Điều trị

Consult ophthalmology emergently regarding

appropriate interventions

(currently no class I treatment evidence, eg, IV/IA tissue plasminogen

activator [tPA] has not been shown to be effective in clinical trials, but

research is ongoing).

bn đòi hỏi ưu tiên đánh giá đột quỵ, nguy cơ cao đột

quỵ não theo sau

(branch (BRVO), or central vein occlusions (CRVO).

BRVO involves one of the branch retinal veins)

Tắc tĩnh mạch võng mạc (Retinal vein occlusion)

Tắc tm phân nữa võng mạc (Hemiretinal vein occlusion).

Tắc tm võng mạc có thể liên hệ phân nữa đáy mắt và có thể gây ra bởi tắc một trong 2 nhánh của tm võng mạc trung tâm, xảy ra 20% (Retinal vein occlusion may involve half of the fundus and may be caused by obstruction of one of the dual trunks of the central retinal vein, an anomaly that occurs in approximately 20 % of individuals.)

Tắc tm võng mạc trung tâm (Central vein occlusions (CRVO)

Occlusion interferes with the drainage of the whole retina. Mechanism is unknown,

(but the most important local factor is chronic open-angle glaucoma, which is present in over 20% of patients).

CRVO is primarily a disease of the elderly but well-documented cases in younger persons have been reported. The ophthalmoscopic features include:

+ marked tortuosity + dilatation of all the retinal branch veins, + diffuse retinal hemorrhages extending from the optic disc to the periphery of the fundus, and multiple cotton-wool patches. Prognosis is poor

Điều trị CRVO

1. Most patients with CRVO, especially the ischemic type. It is important

to determine the cause of the blockage through a medical evaluation.

There is no treatment available for CRVO but there are treatments for

the complications related to CRVO.

+ Injectable medications and steroids can be used to treat macular

edema.

+ Laser treatment called panretinal photocoagulationis used to

prevent neovascular glaucoma. This procedure uses a laser beam to

treat many places on the retina. This technique helps prevent the

growth of new, abnormal blood vessels.

2. CRVO need to see an eye doctor at regular intervals to monitor for

neovascular glaucoma and should be seen earlier and more

frequently if there is a noticeable decrease in vision or eye pain.

Mất thị lực 2 bên bán cấp liên quan ung thư, võng mạc có thể bình thường đặc biệt giai đọan sớm

Cancer-associated retinopathy (CAR): + ảnh hưởng tb nón và que, liên quan kháng thể với protein võng mạc : recoverin + que(Rods ) mediate black-and-white and primarily peripheral vision; bệnh gây photopsias, nhìn kém về đêm và ánh sáng kém, thị trường thu hẹp + nón (Cones )mediate color vision and primarily central vision; bệnh gây giảm thị lực, giảm màu sắc và scotoma central + phần lớn ác tính: Small cell lung cancer. + Steroids có thể cải thiện tạm thời thị lực. .

Paraneoplastic Retinopathies

Melanoma liên hệ retinopathy (MAR): + chỉ ảnh hưởng tế bào que (preserving visual acuity, color vision, and central visual field but affecting night vision and peripheral field). + Associated with melanoma, nearly always after diagnosis, and most frequently after metastatic disease has developed.

+ Acute, usually unilateral, mild to moderate visual loss.

+ Disc edema, followed by macular stellate exudates

(macular star).

+ Most frequently associated with Bartonella henselae

(“cat scratch disease”), but other causes include syphilis,

Lyme disease, sarcoidosis, and toxoplasmosis.

+ không liên hệ MS (multiple sclerosis)

Viêm thần kinh võng mạc

(Neuroretinitis)

Cat-scratch disease (CSD) is a common and usually benign infectious disease

caused by the bacterium Bartonella henselae It is most commonly found in

children following a scratch or bite from a cat within about one to two weeks

Optic disc edema with macular star in the right eye of a patient with cat-scratch disease. There is an adjacent yellow deep retinal- or choroidal-based lesion inferotemporal to the optic disc.

Retinal ganglion cell axons converge on the optic nerve head

and pass through the lamina cribrosa, after which they become

myelinated.(sợi trục tế bào hạch võng mạc hội tụ ở đầu thần

kinh thị và đi qua lamina cribrosa, sau đó được bao bọc myelin)

The optic nerve and retina consist of central nervous system

(CNS) neurons, so they are susceptible to CNS diseases such

as multiple sclerosis (MS). (dễ bị bệnh thuộc hệ tktư như MS)

They do not regenerate like peripheral nerve (không tái sinh)

BN nam 80 tuổi, đột ngột mất thị lực, không đau ở mắt

phải, phù dây tk thị (swelling of the right optic nerve)

Test tiếp theo ?

Điều trị? ESR, CRP, Steroids

Ca lâm sàng

Anterior Ischemic Optic Neuropathy (AION)

Vascular insufficiency in the territory of the posterior ciliary arteries causes infarction of the optic disc, termed anterior ischemic optic neuropathy. (nhồi máu dĩa thị do tắc “đm mi sau”)

+ Acute painless unilateral visual loss,

+ usually age > 50.

+ Optic disc edema must be present acutely and may

only involve a portion of the optic disc

Có 2 thể AION:

■ Nonarteritic:

+ Most common, usually in diabetes, hypertension.

+ Sudden, unilateral, painless, profound visual loss in a

patient with a small cup-to-disc ratio (“disc at risk”).

+ If contralateral cup-to-disc ratio > 0.2, consider giant

cell arteritis in patients > 50 and hypercoagulability/other

causes in younger patients.

The cup-to-disc ratio ( CDR): ophthalmology and optometry: to assess the

progression of glaucoma.

1. optic disc : eye's "blind spot", the area where the optic nerve and blood

vessels enter the retina. The optic disc can be flat or it can have a certain

amount of normal cupping. But glaucoma, which is in most cases

associated with an increase in intraocular pressure, often produces

additional pathological cupping of the optic disc. The pink rim of disc

contains nerve fibers. The white cup is a pit with no nerve fibers. As

glaucoma advances, the cup enlarges until it occupies most of the disc

area.

2. The cup-to-disc ratio compares the diameter of the "cup" portion of the

optic disc with the total diameter of the optic disc. A good analogy to

better understand the cup-to-disc ratio is the ratio of a donut hole to a

donut. The hole represents the cup and the surrounding area the disc. If

the cup fills 1/10 of the disc, the ratio will be 0.1. If it fills 7/10 of the disc,

the ratio is 0.7. The normal cup-to-disc ratio is 0.3. A large cup-to-disc

ratio may imply glaucoma or other pathology. However, cupping by itself

is not indicative of glaucoma. Rather, it is an increase in cupping as the

patient ages that is an indicator for glaucoma. Deep but stable cupping

can occur due to hereditary factors without glaucoma

Non-arteriticanterior ischemic optic neuropathy (NAION)

(Gai thị dị thường)

NAION

■ Arteritic:

+ Caused by giant cell arteritis in patients > 50.

+ Headache, scalp tenderness in 75% of cases.

+ Jaw claudication is the most specific sign.

+ Erythrocyte sedimentation rate (ESR) and C-reactive

protein (CRP) rarely normal.

+ Administer steroids immediately while arranging biopsy to

confirm diagnosis.

+ Contralateral optic neuropathy will develop in 48

hours in one-third of cases, and within 1 week in another

one-third.

Bn nữ 24 tuổi, mất thị lực mắt trái bán cấp kết hợp

đau khi mắt cử động, thị lực 20/200, các chức

năng khác, đáy mắt bình thường’

Test cần thiết ? MRI não

Phân loại ON

Optic neuritis (ON) is optic neuropathy resulting from:

- idiopathic,

- inflammatory,

- infectious,

- demyelinating.

If the optic nerve is swollen on ophthalmoscopy, then the term

papillitis or anterior ON is used.

If the optic nerve is normal on ophthalmoscopy, then it is called

retrobulbar ON.

(trong thực hành lâm sàng, phần lớn bs nhãn khoa dùng

thuật ngữ viêm tk thị (optic neuritis ) mô tả idiopathic hay

demyelinating ON)

Viêm thần kinh hậu nhãn cầu: gai thị bình thường

Viêm gại thi: ứ huyết + phù gai thi

Viêm võng mạc thần kinh: gai thị+hoàng điểm(macular star)

“BN không thấy gì và

BS không thấy gì”

Viêm gai thị (papillitis)

Điểm quan trọng (pearls)

1.Bệnh sử: đau(92% nhẹ) và mất thị lực

2.Chẩn đoán: đồng tử + nhìn màu sắc

3.Dự hậu MS

4.Chẩn đoán hình ảnh thần kinh: MRI não/hốc mắt(T1

đè ép(xóa) mỡ cho thấy orbit với gado)

1.Thường gặp ở nữ 30-40

2.Mất thị lực một bên cấp

3.Đau tăng khi mắt di chuyển, (viêm gai thị không đau)

4.Rối loạn nhìn màu(dyschromatopsia)

5.Tái phát(hầu hết, tiến triển(10%)

6.Mất thị giác tăng bởi nhiệt hay thể dục

(Uhthoff phenomenon)

7.40-70% có triệu chứng thần kinh khác

Lâm sàng

1.Thị lực bắt đầu hồi phục trong 2 tuần

2.35% tái phát bên mắt bệnh

3.Tái phát gấp 2 lần ở bn MS

Diễn tiến

Acute/subacute, central, unilateral visual loss with painful eye movements.

Acute demyelinating:

+ Most common cause.

+ Typically, painful eye movements (> 90%), nadir over

days to 2 weeks, some recovery within 30 days

(ít nhất vài ngày đến 2 tuần)

+ Two-thirds of ON cases are retrobulbar and therefore

produce no disc swelling.

+ If typical ON, magnetic resonance imaging (MRI) to

assess the future risk of the development of MS and guide

need for disease-modifying therapy.

+ Risk of MS at 15 years with one or more lesions, 56%; 0

lesions, 22%.

1.Phần lớn ca: mất thị lực nhẹ, thị trường không ảnh

hưởng, trên MRI không tổn thương: không điều trị

2.Thị lực hồi phục sau vài tuần

3.Điều trị

+ thị lực xấu hơn 6/12

+ đẩy nhanh hồi phục, không ảnh hưởng dự hậu lâu dài

thị lực

Key treatment guidelines:

+ IV steroids → oral taper as per Optic Neuritis Treatment Trial

(ONTT): Quicker recovery of vision, unchanged final visual

outcome.

+ ON with two or more MRI lesions, IV steroids delay the onset

of MS (although same MS risk by 3 years).

+ Oral steroids alone increase risk of recurrent optic neuritis and

should not be prescribed.

+ Risk of MS at 5 years with three or more lesions on MRI, 51%;

1–2 lesions, 37%; 0 lesions, 16%.

+ If there are two or more lesions present on the MRI, treatment

with interferon-β1a (Avonex) in addition to IV steroids reduces

the 3-year risk of MS by 44%.

Thuốc

1.TM corticosteroid( methylprednisolone)

- 1 gr/ngày trong 3 ngày,

- tiếp theo uống prednisone 1mg/kg/ngày trong 11 ngày và

giảm trong 3 ngày

2.TB interferon beta.1a

- giảm nguy cơ phát triển MS trong 3 năm bn nguy cơ cao

Chú ý: uống prednisolone đơn thuần thì chống chỉ định vì không ảnh

hưởng tốc độ hồi phục và nguy cơ tái phát cao hơn

Atypical features (lower MS risk, need to exclude

alternatives)

(các thể không điển hình, nguy cơ MS thấp cần loại trừ)

+ Retinal exudates or hemorrhages.

+ Neuroretinitis (discussed above).

+ Marked optic nerve swelling.

+ No light perception vision at onset.

+ Consider antinuclear antibody (ANA), fluorescent

treponemal antibody absorption test (FTA-ABS), angiotensin-

converting enzyme (ACE), Lyme disease, West Nile virus,

ehrlichiosis, Leber optic neuropathy, chest x-ray, and lumbar

puncture (LP).

Red flags atypical optic neuritis

1.Tuổi<12 hay >50

2.Mất thị lực năng, khởi phát 2 bên, không cải thiện sau 6

tuần, tiến triễn

3.Không đau

4.Gai thị phù nhiều, xuất huyết, uveitis, exudate, retinitis,

phelbitis

5.Tái phát khoảng thời gian ngắn hay giảm steroid

6.Hiện diện bệnh hệ thống

7.Liệt tay chân, cơ vòng, đau khớp, rash ở da, sốt….

■ Bilateral optic disc edema due to increased ICP.

■ Visual acuity typically normal until late or when very

severe. However, peripheral field defects may occur

early and patient may be unaware, so formal visual

testing should always be obtained.

■ Optic nerve edema has features of obscured disc

vessels and a relatively preserved optic cup until late.

■ Hemorrhages and exudates are also frequently present

■ Symptoms of increased ICP:

+ Headache,

+ nausea, vomiting,

+ transient visual obscurations (brief transient visual loss usually associated with coughing/ Valsalva

maneuver, or changes in position),

+ pulsatile tinnitus,

+ diplopia (from cranial nerve [CN] VI palsies).

Papilledema. Note the vessel obscuration at the disc margins with

associated hemorrhages and exudates. Note that the optic cup is

preserved

Idiopathic intracranial hypertension (pseudotumor

cerebri):

+ Typically young (20–30), obese women.

+ Sometimes associated with vitamin A (ie, Accutane) and

tetracycline antibiotics, among many others.

Diagnosis of exclusion requires:

+ Elevated opening pressure (> 25 cm H2O).

+ Normal MRI of the brain.

+ However, note that radiologic signs of chronically-elevated

intracranial pressure may be present, such as posterior

flattening of the globes, dilated and tortuous optic nerve

sheaths, empty or partiallyempty sella, and transverse venous

sinus stenosis.

+ Normal CSF.

+ Computed tomography (CT) or MR venogram to exclude

venous sinus thrombosis.

■ Treated with acetazolamide and initial diagnostic LP. If

progressivevisual loss with medical therapy, surgical

management with a CSF shunting procedure

(ventriculoperitoneal shunt, lumboperitoneal shunt) or optic

nerve sheath fenestration should be pursued

Phân biệt phù gai và viêm gai thị ?

Phù gai thị

Màng nuôi

Màng nhên

Màng cứng

(Autosomal) dominant optic atrophy:

+ Most common inherited optic neuropathy.

+ Slow bilateral visual loss (approximately one line of vision

per decade), frequently first noted at school age but can go

undiagnosed for years.

+ Examine family members for optic nerve pallor.

+ Usually central/cecocentral visual field deficits

Leber hereditiary optic neuropathy:

+ Rare mitochondrial optic neuropathy (maternally

transmitted); for unclear reasons typically affects young

adult males more than women.

+ Acute visual loss first in one eye and then the second,

usually within weeks but always ≤ 1 year.

+ Acute phase: Characteristic hyperemic optic nerve fiber

layer with telangectatic and tortuous peripapillary vessels.

+ Cecocentral scotomas typical.

Typically, bilateral central/cecocentral visual field defects and

color deficiencies.

+ Vitamin B12 or copper deficiency.

+ Methanol (can be severe, within 24 hours postingestion as

MeOH→ formaldehyde by alcohol dehydrogenase). Improper

distillation of alcohol (moonshine) can produce dangerous

concentrations of methanol; sometimes moonshine is distilled

in old radiators made of lead which is also neurotoxic.

+ Ethambutol (usually after several months of treatment).

+ Other medications and exposures: amiodarone, linezolid,

cobalt, toluene (glue-sniffing).

Can be caused by any type of mass lesion compressing the

optic nerve. Key examples include:

Foster-Kennedy syndrome: Intracranial mass, such as an

olfactory groove meningioma plus:

+ Ipsilateral optic pallor (direct compression of optic nerve).

+ Contralateral disc edema (increased ICP).

+ Anosmia from mass effect on the olfactory nerve.

.

Optic nerve sheath meningioma:

+ Typically in middle-aged women (like other

meningiomas).

+ Slowly progressive optic neuropathy.

+ MRI of orbits with contrast and fat saturation (imaging

technique that suppresses orbital fat signal, allowing

examination of intraorbital contents).

+ Treatment: Stereotactic radiation, without biopsy,

because surgical procedures nearly always result in visual

loss

Pituitary adenoma:

+ Can compress an optic nerve or the optic chiasm.

+ Usually slowly progressive visual loss in one eye or a

bitemporal visual field defect.

+ However, when the tumor outstrips its blood supply, a

hemorrhagic infarction can occur (pituitary apoplexy).

Pituitary apoplexy is, in addition to the visual loss, frequently

accompanied by headache and ophthalmoplegia.

It is a life-threatening condition due to acute hypopituitarism.

Optic nerve glioma:

+ Appears before the age of 15 in > 85% of cases.

+ Strongly associated with neurofibromatosis I.

+ Usually extremely slow growing with little visual progression.

+ Follow-up rather than more aggressive treatments is

generally appropriate unless there is evidence of a malignant

course.

Cảm ơn sự theo dõi