Ординатура / Офтальмология / Учебные материалы / Color Atlas of Ophthalmology The Quick-Reference Manual for Diagnosis and Treatment

13 Neuro-Ophthamology 371

Cerebellopont ine angle t um or: Th is m ay cau se sixth -n er ve paresis w ith decreased h earing (eigh th n er ve), seven th -n er ve palsy, fifth -n er ve p alsy, ata xia, an d papilledem a.

Cavernous Sinus Syndrome

In th is syn drom e oth er n er ves (e.g., th e th ird, four th , fifth n er ves) in th e cavern ou s sin us are also involved .

Orbita l Syndrome

In th is syn drom e proptosis is an early sign , an d th e opt ic n er ve m ay app ear n or- m al or dem on st rate at rophy or edem a. Th e oph th alm ic division of th e fifth n er ve is involved . Th e th ird, four th , an d sixth n er ves are also involved . It occu rs du e to traum a, t um ors, or in flam m at ion s.

Isola ted Sixth-Nerve Pa lsy

Isolated sixth -n er ve paralysis can also be seen in th e absen ce of any oth er associated sign s.

Differential Diagnosis

Thyroid eye disease, m yasth en ia gravis, Du an e syn drom e t ype 1, spasm of th e n ear reflex, m edial w all orbital blow -ou t fract u re w ith rest rict ive m yopathy, break in fusion of a congen it al esoph oria

Management

Occlusion

On e can perform occlusion w h en dou ble vision is presen t in lateral gaze in pa- t ien t s w ith m ild sixth -n er ve paresis.

Treatment of the Ca use

On e sh ould determ in e th e cau se an d t reat it .

Surgery

A m axim al recession -resect ion procedure su ffices in m ost in stan ces of in com plete abdu cen s paralysis to restore a u sefu l field of single bin ocu lar vision an d to elim i- n ate th e h ead t u rn . If th ere is a com plete p aralysis of th e lateral rect u s m uscle, on e can perform a t ran sposit ion of th e superior an d in ferior rect us m u scles to th e in - ser t ion of th e lateral rect u s m u scle. Th is is called th e Hu m m elsh eim operat ion . In th is surger y, h alf of th e th ickn ess of th e su perior rect u s (SR) an d in ferior rect u s (IR) are t ran sposed to th e in ser t ion of th e lateral rect u s (LR). Recession of th e m edial rect us (MR) is also don e. In Jen sen’s operat ion also, th e t ran sposit ion is don e w ith recession of th e m edial rect u s. In th is operat ion , th e LR is split as are th e SR an d in ferior rect us (IR). Th en th e split por t ion s of th e SR an d IR are sut u red to th e split por t ion s of th e LR (Figs. 13.4 an d 13.5).

Fig . 13.4 Hum melsheim operation. Half the superior rectus (SR) and inferior rectus (IR) are transposed to the area of the lateral rectus (LR). This is also combined with a re - cession of the MR.

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Fig . 13.5 Jensen operation. The superior rectus (SR), lateral rectus (LR), and the inferior rectus (IR) are split. The superior half of the split MR is sutured to one half of the split SR, and the inferior half of the LR is sutured to one half of the split IR. The MR is also done.

Botulinum Toxin Injection

Tem porar y paralysis of an ext raocular m u scle can be u sed in conjun ct ion w ith th e t ran sposit ion procedu res or in isolat ion . To determ in e th e st ate of recover y of th e LR follow ing a sixth -n er ve palsy, a t iny dose of bot ulin um toxin is injected in to th e belly of th e overact ing m edial rect us m uscle. Th is paralyzes th e m edial rect us an d so th e h orizon tal forces on th e globe are m ore balan ced an d th e esot ropia reduced or elim in ated .

Facial (Seventh) Nerve Palsy

Th e facial n er ve is th e seven th cran ial n er ve, an d it is both a m otor as w ell as a sen sor y n er ve. Th e seven th cran ial n er ve h as th ree n u clei:

Main m otor nucleus: Lies in th e low er part of th e pon s. Th e part of th e n u cleu s th at su pplies th e m u scles of th e upper part of th e face receives cor t icon u clear

fibers from both cerebral h em isph eres. Th e part of th e n ucleu s th at sup plies th e m uscles of th e low er par t of th e face receives cort icon u clear fibers from th e opposite cerebral h em isph ere on ly.

Parasym pathet ic nuclei: In clu de th e superior salivator y an d lacrim ator y n uclei. Th e form er sup plies th e subm an dibu lar an d sublingu al glan ds an d th e lat ter th e lacrim al glan d .

Sensory nucleus: Sit u ated in th e u pper par t of th e m edulla oblongat a

Presentation

Th e lesion s of th e facial n er ve are sh ow n in Figure 13.6 an d are described in th e follow ing sect ion s.

Supra nuclear Lesion

If th e lesion is su pran u clear on ly th e low er h alf of th e face is involved, an d if it is a low er m otor n eu ron lesion th e w h ole h alf of th e face is involved . Th is is because th e u pper h alf of th e face h as a bilateral in n er vat ion .

Cerebellopontine Angle Tumor

Th e seven th n er ve m ay be affected by a cerebellopon t in e angle t u m or as it exit s th e brain . Th e presen t ing sign s in clude:

Tot al ipsilateral facial w eakn ess (seven th -n er ve involvem en t)

Decreased tearing (lacrim at ion involved)

Hyperacusis (n er ve to stapedius involved)

13 Neuro-Ophthamology 373

Fig . 13.6 Lesions of the facial nerve: 1, supranuclear lesion; 2, cerebellopontine angle tumor; 3, geniculate ganglionitis (Ramsay-Hunt syndrome); 4, isolate ipsilateral tear de - ficiency; 5, lesion before nerve to stapedius; 6, lesion after nerve to stapedius; 7, lesion after chorda t ympani nerve; 8, Bell palsy—isolated total ipsilateral facial palsy; 9, isolated partial ipsilateral facial palsy.

Geniculate Ganglionitis

Gen iculate ganglion it is is kn ow n as th e Ram say-Hun t syn drom e an d is ch aracterized by th e follow ing feat u res:

Sam e fin dings as in cerebellopon t in e-angle t u m ors except n o associated n eurological deficits

Th ere m ay be zoster vesicles on th e t ym pan ic m em bran e, extern al au ditor y ca- n al, or extern al ear.

Isola ted Ipsila tera l Tea r Deficiency

Isolated ipsilateral tear deficien cy occu rs in n asoph ar yngeal carcin om as, w h ich affect th e vidian n er ve or th e pter ygopalat in e ganglion .

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Lesion before Nerve to Sta pedius

Lacrim at ion is n orm al. Th e oth er fin dings are as follow s:

Hyperacusis (n er ve to stapediu s involved)

Decreased t aste from th e an terior t w o th irds of th e tongu e (ch orda t ym pan i n er ve involved)

Total ipsilateral facial w eakn ess (seven th -n er ve involvem en t)

Lesion a fter Nerve to Sta pedius

Decreased t aste from th e an terior t w o th irds of th e tongu e (ch orda t ym pan i n er ve involved)

Total ipsilateral facial w eakn ess (seven th -n er ve involvem en t)

Lesion a fter Chorda Tympa ni Nerve

On ly tot al ipsilateral facial w eakn ess (seven th -n er ve involvem en t)

Bell Palsy

On ly tot al ipsilateral facial w eakn ess (seven th -n er ve involvem en t)

Isola ted Pa rtia l Ipsilateral Fa cial Palsy

In th is con dit ion on ly cer tain bran ch es of th e seven th -n er ve are affected .

Differential Diagnosis

Parkin son ism , basal ganglia lesion

Management

Work up an d t reat according to cause.

Multiple Cranial-Nerve Palsies (Cavernous Sinus Syndrome and Orbital

Apex Syndrome)

Causes of m u lt iple cran ial-n er ve palsies can be t rau m at ic, vascu lar (in tern al carot id ar ter y an eu r ysm , posterior cerebral ar ter y an eu r ysm , direct or in direct carot id cavern ou s fist ulas, th rom bosis, etc.), n eop lasm s (m ay be prim ar y cran ial t u - m ors or m et ast asis), in flam m at ion s, an d in fect ion s su ch as h erp es zoster, syph ilis, t u bercu losis, m ucorm ycosis.

Presentation

Pat ien ts presen t w ith periorbital or epicran ial pain , ipsilateral ocular m otor n er ve palsies, ocu losym path et ic paralysis, an d sen sor y loss in th e oph th alm ic an d m axillar y division of th e t rigem in al n er ve. Orbital apex syn drom e occurs ow ing to a sim ilar cau se at th e apex of th e orbit an d is dist ingu ish ed by involvem en t of th e opt ic n er ve in it .

Management

Man agem en t is directed tow ard th e cau se.

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(Relative) Afferent Pupillary Defect

Com m on causes in clude opt ic n er ve involvem en ts (opt ic n eurit is, com pression of opt ic n er ve, an terior isch em ic opt ic n eu ropathy, etc.), den se m edia opacit y, ret in al cau ses (e.g., RD, cen t ral ret in al vein occlu sion or bran ch ret in al vein occlusion , cen - t ral serou s ret in och oroidopathy, etc.) Also called Marcus Gun n p upil.

Presentation

Th e con dit ion can be detected by th e sw inging flash ligh t test . Th e test can be perform ed in corn eal opacit y, th ird -n er ve palsy, or an at ropin ised pup il as it is n ot related to visu al acuit y. Sin ce relat ive afferen t pu pillar y defect occurs in con dit ion s w h ere th ere is a relat ive decrease in th e con duct ion of th e opt ic n er ve as com pared to n orm al, it is absen t in bilateral sym m et rical opt ic n er ve or ret in al lesion s.

To perform th e sw inging flash ligh t test th e exam in er sh in es a brigh t ligh t in to th e n orm al eye w h ile th e pat ien t is fixing on a dist an ce t arget . Th e ligh t is kept 3 to 5 cm from th e eye just below th e visu al axis. Th e speed an d exten t of con st rict ion are obser ved . A n orm al direct an d con sen su al ligh t reflex can be obser ved . Ligh t is th en sh ifted briskly to th e con t ralateral eye. Each eye is illum in ated for ~1 secon d an d pup illar y react ion is obser ved . Th e affected eye sh ow s paradoxical dilatat ion in stead of con t ract ion .

Differential Diagnosis

Oth er pu pillar y abn orm alit ies

Horner Syndrome

Horn er syn drom e occurs in lesion s involving th e sym path et ic pupillom otor path - w ay.

Presentation

Pat ien t s presen t w ith m iosis, n orm al pu pillar y react ion to ligh t , an d n ear, in creased an isocoria in dim con dit ion s, ptosis, ip silateral an h idrosis (in lesion s proxim al to carot id bifu rcat ion ), en op h th alm os, loss of ciliospin al reflex (in lesion s distal to th e ciliospin al cen ter of Bu dge), hyp och rom ic an isocoria (eye w ith Horn er syn drom e is ligh t in color) (Fig. 13.8).

Differential Diagnosis

Cen t ral an isocoria

Management

Invest igat ion s in clu de th e follow ing ph arm acological tests:

Cocaine test: Cocain e (4%) is in st illed in both eyes. Th e Horn er pu pil w ill n ot dilate (>0.8 m m an isocoria sign ifican t). Noradren alin reu ptake is blocked by cocain e cau sing dilatat ion . In Horn er syn drom e n o n oradren alin is p resen t at th e n er ve en dings.

Hydroxyam phetam ine test: Hydroxyam ph etam in e (1%) is in st illed in both eyes. In preganglion ic lesion s both pu pils w ill dilate an d in postganglion ic lesion s th e Horn er pu pil w ill n ot dilate. Noradren alin e release is poten t iated by Paredrin e (hydroxyam ph et am in e) causing dilat at ion . In postganglion ic lesion s n eu ron s are dest royed so n o dilatat ion is seen .

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Adrenaline test: Adren alin e 1:1000 is in st illed in both eyes. No dilatat ion is seen in preganglion ic lesion s, bu t dilat at ion of a Horn er pu pil is presen t in postgan -

glion ic lesion s because adren alin e is n ot broken dow n becau se of th e absen ce of m on oam in e oxidase (MAO) in h ibitor in dest royed n er ve en dings. Th is is du e to “den er vat ion hypersen sit ivit y” to adren ergic n eu rot ran sm it ter.

Other investigations: Magnetic resonance im aging (MRI) of the brain/spinal cord/ orbit; com puted tom ography (CT) of the thorax; Doppler of the carotid; ear, nose, and throat (ENT) assessm ent; chest x-ray. Treatm ent depends on the exact cause and site of the lesion . The patient is referred to a suitable specialist .

Argyll-Robertson Pupil

Th is con dit ion is u su ally seen in pat ien ts suffering from syph ilis. It sh ow s a bilateral an d asym m et rical involvem en t . Lesion s u sually affect th e n eu ron s of th e pretectal area.

Presentation

Sign s in clu de bilateral, m iot ic, irregular pup il w ith asym m et rical respon se to ligh t an d n ear st im ulu s for accom m odat ion . Ligh t reflex is absen t an d accom m odat ion is ret ain ed . Th e m ain associated causes are tert iar y syph ilis, diabetes m ellit u s, Wern icke en ceph alopathy, en ceph alit is, h eredit ar y n eu ropath ies, m idbrain t u - m ors, h erpes zoster oph th alm icu s, an d ch ron ic alcoh olism .

Management

Man agem en t addresses th e u n derlying cau se.

Adie Pupil/Tonic Pupil

Adie ton ic pu pil result s from dam age to th e postganglion ic parasym path et ic n er ve su pply to th e sp h in cter pu pillae. Th is is seen in young adult s an d is un ilateral in 80%.

Presentation

Sign s in clude a large, regu lar pu pil w ith poor ligh t react ion an d exaggerated, slow, su st ain ed n ear respon se (ton ic) w ith ch aracterist ic verm iform m ovem en t s of th e pupillar y border on slit lam p . Ligh t-n ear dissociat ion is p resen t . In ch ron ic cases, th e pup il becom es poor an d poorly dilat ing.

Th is con dit ion is associated w ith dim in ish ed deep ten don reflexes (Adie syn - drom e) an d patchy hypoh idrosis (Ross syn drom e).

Management

Invest igat ion s in clu de ph arm acological test s (e.g., in st illat ion of 0.125% pilocarpin e in both eyes). An Adie pu pil con st ricts, w h ereas th e n orm al pu pil does n ot becau se of parasym path et ic den er vat ion supersen sit ivit y. Reassu re th e pat ien t about any obvious an iscoria an d accom m odat ive dysfu n ct ion . Pilocarp in e (0.1%) h elps in redu cing th e m ydriat ic blu rring. Glasses also h elp w ith accom m odat ive dysfu n ct ion .

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Fig. 13.9 Arterial loop. Color photograph shows a tortuous vessel above the optic disk. (Courtesy of

Robin D. Hamilton, A.M. Hamilton)

Developmental Optic Nerve Anomalies

Prepapillary Vascular Loop

These blood vessels project from the optic disk into the vitreous and return to the optic disk to continue their usual course; 80 to 90%are arterial in origin (Fig. 13.9).

Presentation

Prepapillar y vascu lar loop is an in ciden t al fin ding.

Optic Nerve Hypoplasia

Th is con dit ion is ch aracterized by a decreased n u m ber of opt ic n er ve axon s an d n orm al m esoderm al an d glial supp or t ing t issue.

Presentation

Visual acu it y m ay range from 20/20 to percept ion of ligh t . Op h th alm oscopically th e disk appears sm all an d pale. A peripapillar y h alo surroun ded by a pigm en t ring (dou ble-ring sign ) is alw ays presen t .

De Morsier syn drom e is a com bin at ion of opt ic n er ve hypoplasia, absen ce of sept um pellu cidu m , an d agen esis or par t ial developm en t of th e corpus callosum . Coexisten t h em isph eric abn orm alit ies an d absen ce of pit uit ar y in fun dibulu m w ith or w ith ou t post pit u it ar y ectopia m ay be presen t . Pit uitar y h orm on e deficien cy m ay be p resen t .

Management

Man agem en t con sist s of n eu rological an d en docrin ological evalu at ion s w ith su p - plem en tat ion of requ ired h orm on es.

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Optic Nerve Pit

Opt ic n er ve pit is h ern iat ion of rudim en t ar y n eu roectoderm al t issu e in to a pocketlike depression w ith in th e n er ve substan ce w ith u n kn ow n p ath ogen esis.

Presentation

A roun d or oval gray-w h ite or yellow ish depression is seen in th e opt ic disk, preferably at th e tem poral m argin . Associated visu al field defects m ay be presen t , m ost com m on ly paracen t ral arcuate scotom a. Th ere is a 45% risk of serous ret in al detach m en t .

Differential Diagnosis

Acquired depression in th e opt ic disc in n orm al ten sion glau com a pat ien t s, opt ic n er ve colobom a, cen t ral serou s ret in opathy (CSR), age-related m acular degen era- t ion , pigm en t ep ith eliu m det ach m en t

Management

Pat ien ts sh ou ld be given regular follow -u p . Laser p h otocoagu lat ion is p erform ed at th e peripapillar y ret in a adjacen t to th e pit if serou s ret in al det ach m en t is presen t . In tern al gas t am pon ade is recom m en ded for ret in al detach m en t .

Optic Disk Coloboma

Opt ic disk colobom a is a sp oradic or au tosom al dom in an t con dit ion arising from fau lt y closure of th e em br yon ic opt ic cup .

Presentation

Visual acuit y is variably affected . Th ere is visu al-field defect depen ding on th e n er ve fiber involvem en t . An en larged, w h ite, glisten ing, bow l-sh aped disk w ith cen t ral excavat ion , w h ich m ay exten d to th e ret in a an d ch oroid . Microoph th alm ia m ay presen t .

Associat ion s in clu de CHARGE syn drom e (colobom a of iris or ret in och oroid, heart an om aly, ch oan al at resia, ret ardat ion , gen ital an om alies, ear an om alies), Golt z focal derm al hypoplasia, Walker-Warburg syn drom e, lin ear n evus sebaceous syn drom e, an d Golden h ar syn drom e. Opt ic disk colobom a is rarely associated w ith t ran ssph en oidal en ceph alocele (Fig. 13.10A).

Management

Visual-field test ing m ust be don e. Obser vat ion is n eeded .

Morning Glory Syndrome

Morn ing glor y syn drom e is due to a fun n el-sh aped expan sion of th e distal por t ion of th e opt ic stalk, w h ich is due to n orm al closure bu t abn orm al progression of closu re of th e em br yon ic fissure in th e distal por t ion of th e opt ic st alk. It is sporadic in occurren ce (Fig. 13.10B).