Diagnosis and Treatment of Ophthalmology Related Cerebral Arterial Circulation Diseases: A 3D Animated Encyclopedia

Abstract

Cerebral circulation is the flow of blood through a group of arteries and veins which supply the brain. There are various diseases related to ophthalmology, due to pathologies in the cerebral arterial system. Arteries inside the skull can be blocked by plaque or disease, which in turn triggers a series of events leading to various cranial nerve palsies, visual fields defects, retinal diseases, etc. The highlights of this chapter are the novel three-dimensional (3D) animative videos created by us, to simplify various cerebral arterial circulation diseases and their diagnostic concepts for neophytes. 3D animative videos can aid learning and help in the cognitive concept building of these complex pathologies.

1. Introduction

Cerebrovascular disease is the 2nd most common cause of death in the world and the 6th most common cause of disability [1, 2]. Cerebrovascular diseases occur primarily during old age. The risk of cerebrovascular disease occurring increases significantly after 65 years of age.

Cerebrovascular conditions include aneurysms, arteriovenous malformations (AVM), cerebral cavernous malformations (CCM), arteriovenous fistula (AVF), carotid-cavernous fistula (CCF), carotid stenosis, transient ischemic attack (TIA), and stroke [3, 4, 5, 6, 7, 8, 9]. In this chapter, various cerebral arterial circulation diseases related to ophthalmology are explained in detail using detailed three-dimensional (3D) animative videos.

2. Pathologies

2.1 Anterior communicating artery aneurysms

It can lead to visual field defects and visual deterioration such as bitemporal heteronymous, psychopathology, and frontal lobe pathologies are shown in Video Clip 1 [10].

(Video 1, https://www.youtube.com/watch?v=HoQNbzUTJu0).

2.2 Posterior communicating artery aneurysm

Oculomotor nerves are more prone to damage from posterior communicating artery (PComA) aneurysms. Pathophysiology and clinical features of oculomotor nerve palsy are shown in Figure 1 and Video Clip 2, respectively [10, 11].

Figure 1.

Pathophysiology of oculomotor nerve palsy caused by posterior communicating artery aneurysm.

(Video 2, https://www.youtube.com/watch?v=EZ9sQksL_oc).

2.3 Terson’s syndrome

Terson’s syndrome (TS) is the occurrence of intraocular haemorrhage, manifesting as vitreous, subhyaloid, intraretinal bleeding, or subretinal bleeding, which typically occurs in a setting of traumatic brain injury associated with intracranial haemorrhage [12]. The pathophysiology of TS is shown in Figure 2. The clinical features of TS primarily depend on the patient’s neurological status and the location of the haemorrhage.

Figure 2.

Pathophysiology of Terson’s syndrome due to raised intracranial pressure.

2.4 Posterior inferior cerebellar artery syndrome or lateral medullary syndrome

Lateral medullary syndrome (LMS) occurs due to vascular insult in the lateral part of the medulla oblongata [13]. It was named after a Jewish neurologist, Adolf Wallenberg [14]. The aetiology of LMS is shown in Figure 3. The patient presents with clinical features of vertigo, ataxia, nystagmus, oscillopsia, diplopia, dysphagia, nausea, vomiting, headache, impairment of pain and thermal sensation, ipsilateral Horner’s syndrome, ipsilateral limb ataxia, dysphonia, hiccups and ipsilateral hyperalgesia. The specific ophthalmic clinical sign for LMS is ipsipulsion.

Figure 3.

Aetiology of posterior inferior cerebellar artery syndrome or lateral medullary syndrome.

2.5 Carotid-cavernous fistula

Carotid-cavernous fistula (CCF) occurs due to an abnormal connection between the carotid artery and the cavernous sinus. It can be classified as direct or indirect CCF [15, 16]. Types of CCF are shown in Figure 4 and Video Clip 3. (Video 3, https://www.youtube.com/watch?v=PYE_NveoIoo).

Figure 4.

Classifications of carotid-cavernous fistula.

2.6 Brainstem stroke syndromes

The ocular manifestations that occur in patients with brainstem stroke due to vascular ischemia are shown in Figure 5.

Figure 5.

Various ocular manifestations of the brainstem stroke syndrome.

2.6.1 Oculomotor nerve palsy

Isolated third nerve palsies are rare; hence it is important to evaluate other cranial nerves and the peripheral nervous system [17]. Clinical features of oculomotor nerve palsy are shown in Video Clip 4.

(Video 4, https://www.youtube.com/watch?v=erN1kQ9-vuk).

2.6.2 Trochlear nerve palsy

The patient typically presents with binocular diplopia which is vertical or torsional. Park-Bielschowsky three-step test (Figure 6) has been proposed to identify superior oblique palsy in such patients [18]. Clinical features of trochlear nerve palsy are shown in Video Clip 5.

Figure 6.

Park-Bielschowsky three-step test to identify superior oblique palsy.

(Video 5, https://www.youtube.com/watch?v=GOYj1EoN3Ss).

2.6.3 Abducens nerve palsy

The patient presents with horizontal diplopia and esotropia, due to unopposed action of the medial rectus. Abduction of the affected side will be restricted. The patient will adapt a compensatory face turn towards the side of paralysed muscle [19, 20]. Clinical features of abducens nerve palsy are shown in Video Clip 6.

(Video 6, https://www.youtube.com/watch?v=Ecuve0RiTZQ).

2.6.4 Parinaud dorsal midbrain syndrome

The clinical triad of parinaud dorsal midbrain syndrome (Figure 7) is supranuclear upgaze palsy, convergence retraction nystagmus, and light-near dissociation [21, 22]. Clinical features of parinaud dorsal midbrain syndrome are shown in Video Clip 7.

Figure 7.

Clinical triad of dorsal midbrain syndrome.

(Video 7, https://www.youtube.com/watch?v=PF3n6fVEZ3o).

2.6.5 Skew deviation

It is a supranuclear motility disorder that occurs due to brainstem or cerebellar stroke. The eyes deviate vertically and often present with cyclotorsional disturbances [23]. Clinical features of skew deviation are shown in Video Clip 8.

(Video 8, https://www.youtube.com/watch?v=1GeTQTpozJ4).

2.6.6 Horizontal gaze palsy

Ipsilateral horizontal gaze palsy is caused by a lesion in the horizontal gaze centre of paramedian pontine reticular formation (PPRF), which clinically manifests as an inability to look in the direction of the lesion. Clinical features of horizontal gaze palsy are shown in Video Clip 9.

(Video 9, https://www.youtube.com/watch?v=NQt_-nkcfuA).

2.6.7 Internuclear ophthalmoplegia

Ischemia in the vertebrobasilar system can produce an ischemic internuclear ophthalmoplegia (INO) [24]. In cases of unilateral INO, it clinically manifests as adduction deficit, where defective adduction of the eye will be present on the side of the lesion and nystagmus of the contralateral eye on abduction will be noted [25]. Bilateral INO will lead to defective left adduction and abduction nystagmus of the right eye on the right gaze and defective right adduction and abduction nystagmus of the left eye on the left gaze. Clinical features of internuclear ophthalmoplegia are shown in Video Clip 10.

(Video 10, https://www.youtube.com/watch?v=bQH1wPmN5aE).

2.6.7.1 Wall-eyed bilateral internuclear ophthalmoplegia

Exotropia (XT) need not be present in all cases of bilateral INO. The most common aetiology of wall-eyed bilateral internuclear ophthalmoplegia (WEBINO) is infarction at the level of the midbrain [26].

2.6.7.2 Wall-eyed monocular internuclear ophthalmoplegia

In wall-eyed monocular internuclear ophthalmoplegia (WEMINO), patients will have a unilateral medial longitudinal fasciculus (MLF) lesion with primary position XT [27].

2.6.7.3 One and a half syndrome

The patient will retain only the abduction of the contralateral eye, which will exhibit abduction nystagmus [28]. This condition is termed as one and a half syndrome.

2.6.7.4 Eight and a half syndrome

There is also conjugate horizontal gaze palsy on looking to one side, followed by INO on looking to the opposite side, along with ipsilateral lower motor neuron (LMN) facial weakness [29]. This condition is termed as eight and a half syndrome.

2.6.7.5 Half and half syndrome

There is ‘half’ of a horizontal gaze palsy plus half of the ipsilateral gaze (abduction deficit from CN VI fascicular palsy) [30]. This condition is termed as half and half syndrome.

2.6.7.6 Posterior INO of Lutz

Lesions interrupting the fibre tracts that connect the pontine centre for conjugate horizontal gaze and the ipsilateral abducens nucleus can cause posterior INO of Lutz [31].

2.7 Chiasmal strokes

Chiasmal strokes typically present as bitemporal hemianopia [32]. In cases of anterior chiasmal strokes, it will produce central scotoma in one eye and temporal field defects in the other eye [33, 34]. Clinical features of chiasmal strokes are shown in Video Clip 11.

(Video 11, https://www.youtube.com/watch?v=mMy2C_AN-Ho).

2.8 Post chiasmal strokes

Clinical features of post chiasmal stroke are shown in Video Clip 11.

(Video 11, https://www.youtube.com/watch?v=mMy2C_AN-Ho).

2.8.1 Optic tract stroke

Lesions usually produce contralateral incongruous homonymous hemianopia along with optic tract syndrome [35].

2.8.2 Lateral geniculate body stroke

In case of extensive lateral geniculate body (LGB) injury, it would produce complete homonymous hemianopia [36, 37].

2.8.3 Optic radiation stroke

Lesions of the anterior optic radiation cause incongruous visual field defects. The field defects become more congruous as it goes more posterior [37].

2.8.4 Temporal lobe stroke

Contralateral homonymous superior quadrantanopia (“pie-in-the-sky” defect), occurs with temporal lobe infarction involving Meyer’s Loop, which constitutes the inferior visual fibres [38].

2.8.5 Parietal lobe stroke

Contralateral homonymous inferior quadrantanopia (“pie-on-the-floor” defect) occurs, with additional systemic manifestations depending on the side of the lesion [39, 40].

2.8.6 Occipital lobe stroke

Most occipital lobe lesions are a result of a stroke at the level of the posterior cerebral artery (PCA) and will cause no neurological deficits other than vision loss. Occipital lobe lesions can produce a varied presentation of visual field defects [38].

3. Investigations

• Gold standard modalities for investigating anterior and posterior communicating artery aneurysms are magnetic resonance angiography (MRA), computed tomography angiography (CTA), lumbar puncture (LP), cerebral angiogram and digital subtraction angiography (DSA).

• Regarding Terson’s syndrome, if necessary, an ultrasound B-scan imaging of the eye would be needed to rule out intraocular haemorrhages [41].

• Lateral medullary syndrome will require a thorough systemic evaluation to rule out diabetes mellitus, hypertension and heart disease. Complete blood work-up, cardiac investigations like electrocardiogram (ECG), echocardiography and carotid Doppler. CTA and MRA will provide a precise location of the infarct [42].

• In CCF, the prominence of the superior ophthalmic vein (SOV) and the diffuse enlargement of the extraocular muscles are demonstrated by CT and MRI. Additionally, orbital Doppler imaging can be used to assess abnormal flow patterns, especially in the SOV. To classify CCF and plan the mode of management, selective catheter DSA, CTA and MRA can be useful [43, 44, 45].

• The first step for investigating a stroke would be non-contrast CT to rule out haemorrhagic stroke. MRI with diffusion-weighted imaging (DWI) is required for evaluating posterior circulation strokes. It is mandatory to do a thorough clinical ophthalmic examination of visual acuity determination, pupillary exam, fundoscopy, and visual field testing [46, 47].

4. Visual rehabilitation

Vision rehabilitation is mandatory as vision loss can cause a major impact on the patient’s life. Low vision therapy is important to treat and manage the symptoms of vision loss. Optical therapy incorporates the use of mirrors and prisms to enhance the patient’s visual field. Strategies are devised to help the patients compensate and adapt to their visual impairment.

5. Recommendations

• Periodic radiographic imaging (either MRA, CT scan or conventional angiography) should be recommended at intervals to monitor the size and/or growth of the aneurysm in all cerebral artery aneurysm patients to avoid severe vision-threatening outcomes.

• There is general agreement to recommend cardiac monitoring, airway support and ventilatory assistance in the treatment of haemorrhagic and ischemic stroke patients.

• Strabismus surgery should be considered to correct the ocular misalignment associated with brainstem strokes, if not resolving on its own after 6 months.

• Visual rehabilitation can help make use of the remaining vision and other skills to increase independency.

• Role of an orthoptist is important to assess and treat the range of eye problems, pertaining to eye movements in cases of ophthalmoplegia.

6. Conclusions

Cerebral arterial circulation diseases are a complex group of diseases, which are confusing and hard to understand for neophyte residents. Understanding the cause and pathophysiology of these diseases (in a realistic way with the help of 3D animations), helps them to tackle these pathologies effectively [48]. In this chapter, we have used 3D animations and have taken the medical field from a field of theoretical curiosity into a world of animative reality.

Acknowledgments

We are grateful to Mr. Pragash Michael Raj - Department of Multimedia, Mahathma Eye Hospital Private Limited, Trichy, Tamil Nadu, India for his technical support throughout the making of this chapter and its illustrations. We sincerely thank Ms. Banasmita Mohanty for her support in proofreading the chapter.

Conflict of interest

The authors declare no conflict of interest.

Notes/thanks/other declarations

I (Dr. Prasanna Venkatesh Ramesh) owe a deep sense of gratitude to my daughters (Pranu and Hasanna) and family (in-laws) for all their prayers, support, and encouragement. Above all, I extend my heartfelt gratitude to all the patients who consented to the images which are utilised for this chapter.

I (Dr. Shruthy Vaishali Ramesh) want to thank my partner (Arul) for his constant support and encouragement during the process of creating this chapter.

I (Ms. Prajnya Ray) would like to offer my special thanks to Mr. Deepak Kumar Panda for his constant support and never-ending encouragement, and my parents for their support and motivation during the process of framing this chapter.

I (Mr. Aji Kunnath Devadas) want to thank my parents (Mr. Devadas K and Mrs. Sheeba Devadas) for their constant support and encouragement during the process of creating this chapter.

Declaration of patient consent

In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the chapter. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Nomenclature

3D

Three-dimensional

AVF

Arteriovenous Fistula

AVM

Arteriovenous Malformations

CCF

Carotid-Cavernous Fistula

CCM

Cerebral Cavernous Malformations

CN

Cranial Nerve

CT scan

Computed Tomography Scan

CTA

Computed Tomography Angiography

DSA

Digital Subtraction Angiography

DWI

Diffusion-Weighted Imaging

ECG

Electrocardiogram

ECHO

Echocardiography

INO

Internuclear Ophthalmoplegia

LGB

Lateral Geniculate Body

LMN

Lower Motor Neuron

LMS

Lateral Medullary Syndrome

LP

Lumbar Puncture

MLF

Medial Longitudinal Fasciculus

MRA

Magnetic Resonance Imaging Angiography

MRI

Magnetic Resonance Imaging

PCA

Posterior Cerebral Artery

PComA

Posterior Communicating Artery

PPRF

Paramedian Pontine Reticular Formation

SOV

Superior Ophthalmic Vein

TIA

Transient Ischemic Attack

TS

Terson’s Syndrome

WEBINO

Wall-Eyed Bilateral Internuclear Ophthalmoplegia

WEMINO

Wall-Eyed Mono-Ocular Internuclear Ophthalmoplegia

XT

Exotropia