Cortical blindness encompasses loss of vision, which is generally severe but may be of various degrees in some occasions. Distinct types of the condition are Riddoch syndrome and Anton-Babinski syndrome. Patients who suffer from the Riddoch syndrome experience a loss of vision related to static objects, while they can see anything that is moving. Moving objects may lack color or significant detail. The Anton-Babinski syndrome involves total loss of vision, accompanied by the patient's unawareness that they can no longer see. Patients are unable to discern objects, walk or orientate, but remain convinced that their ability to see has not been damaged. They insist that they are being lied to, but they usually become suspicious when they collide with objects or fall into walls. Hallucinations are also a frequent observation in patients with cortical blindness.

• Epilepsy

  We describe here three girls from two nonconsanguineous families affected by a clinical entity characterized by dysmorphic features, early-onset intractable epilepsy, intellectual disability, and cortical blindness. [ncbi.nlm.nih.gov]

  Furthermore, some patients regain vision completely, as is the case with transient cortical blindness associated with eclampsia and the side effects of certain anti-epilepsy drugs. Recent research by Krystel R. [en.wikipedia.org]

  Some children with Cortical Blindness have additional neurological deficits such as cerebral palsy, epilepsy, various spinal and cranial defects, and intellectual disability. [birthdefects.org]

• Falling

  A 56-year old female reported having had a fall two weeks prior to presentation. Computed Tomography (CT) scan showed an acute right-sided convexity subdural haematoma. A computed tomography angiogram revealed no vascular anomaly. [ncbi.nlm.nih.gov]

  Diagnosed in an animal on the absence of a menace reflex, walking into obstructions and failure to indicate awareness of a soundless movement in its visual field, e.g. a falling cotton ball or feather. [medical-dictionary.thefreedictionary.com]

  But this could easily happen with a blow to the back of the head or can occur after a fall where the back of the head strikes a wall, the floor, stairs, or almost anything else. [writersforensicsblog.wordpress.com]

  Geriatric patients commonly experience this injury through falls, and a wide variety of patients suffer ocular or orbital trauma from motor vehicle crashes. [mayoclinic.org]

  Go to Fall 1998 Table of Contents. [tsbvi.edu]

• Developmental Disorder

  Explore these free sample topics: -- The first section of this topic is shown below -- Basics Description Cortical malformations are important in clinical neurology, as they are associated with developmental disorders, motor impairments, and epilepsy. [unboundmedicine.com]

  Systemic Features: The hallmark signs of this disorder consist of developmental delay and epilepsy. [disorders.eyes.arizona.edu]

• Pneumonia

  Our objective is to present a case of an uncommon complication associated with Mycoplasma pneumoniae infection in a child where cortical blindness was the main clinical feature. Stroke due to an infection by M. pneumoniae is very uncommon. [ncbi.nlm.nih.gov]

• Nausea

  Approximately 3 hours after the procedure, the patient started complaining of a slight headache and nausea along with bilateral cortical blindness. [ncbi.nlm.nih.gov]

  She, however, had nausea and vomiting. She has a longstanding history of well controlled hypertension and a three-year history of Type 2 Diabetes. She denied having migrainous headaches. [caribbean.scielo.org]

  By the following day, she was able to see shapes and shadows but had persistent headache and nausea. A repeat CT brain scan did not show any residual abnormality. During the next 48 hours, her vision progressively returned. [mja.com.au]

  Symptoms usually start during the procedure or in the following 12 hours, with varying symptoms which can include cephalalgia, disorientation, nausea, vomiting, or decrease in the level of consciousness, accompanied by the sudden onset of a complete loss [revespcardiol.org]

• Failure to Thrive

  However, infants and young children may present with failure to thrive, developmental delay, and learning disabilities. Neurosensory deafness is often seen and peripheral neuropathy is usually evident. [disorders.eyes.arizona.edu]

• Bruxism

  […] hemisection) resulting in ipsilateral weakness and loss of vibration proprioception and contralateral loss of pain sensation Brudzinski’s sign involuntary flexion of the hips in response to passive flexion of the neck; indicative of meningeal irritation bruxism [strokecenter.org]

• Hypotension

  We report an 11-year-old female patient with muscular dystrophy who underwent posterior spinal fusion and instrumentation under hypotensive anesthesia for scoliosis who developed transient cortical blindness. [ncbi.nlm.nih.gov]

  In cases of angiography-induced cortical blindness, it is believed that the contrast material may cause significant hypotension and blood flow reduction to the brain, vasospasm or disrupt the blood-brain barrier. [symptoma.com]

  Hirsch, Cortical Blindness in a Preeclamptic Patient After a Cesarean Delivery Complicated by Hypotension, Anesthesia & Analgesia, 91, 3, (609), (2000). Mišo Šabovič, Barbara Bonač and M. [doi.org]

  The differential diagnosis of the visual impairment after cardiac catheterization includes thromboembolism (posterior cerebral artery/top of the basilar artery syndrome), vasospasm of the posterior cerebral arteries, contrast-induced hypotension, hysterical [jpma.org.pk]

  Am J Obstet Gynecol 1995; 172: 1291–8Cunningham, FG Fernandez, CO Hernandez, C Borromeo CJ, Blike GT, Wiley CW, Hirsch JA: Cortical blindness in a preeclamptic patient after a cesarean delivery complicated by hypotension. [anesthesiology.pubs.asahq.org]

• Tachycardia

  The patient didn't arrest during surgery, but had an episode to sinus tachycardia of 180 minutes per minute that didn't turn into ventricular fibrillation, and thus no DC shock was given. [ncbi.nlm.nih.gov]

• Visual Impairment

  The two types of visual disorders (ocular & neurological) can coexist. Cortical visual impairment (CVI) is a neurological visual disorder. It is the fastest growing visual impairment diagnosis today. [web.archive.org]

  Cortical blindness and cortical visual impairment (CVI), which refers to the partial loss of vision caused by cortical damage, are both classified as subsets of neurological visual impairment (NVI). [en.wikipedia.org]

  Cortical Visual Impairment (CVI) is a temporary or permanent visual impairment caused by the disturbance of the posterior visual pathways and/or the occipital lobes of the brain. [dhs.wisconsin.gov]

  Comment: Cortical or cerebral visual impairment in children: A brief overview. Journal of Visual Impairment and Blindness, 104(10), 585-592. [aph.org]

  Though progressive multifocal leucencephalopathy (PML) may manifest with visual impairment, including bilateral visual loss as the presenting manifestation, in single patients, it has not been described in association with left ventricular hypertrabeculation [ncbi.nlm.nih.gov]

• Diplopia

  The patient postoperatively presented with diplopia and mental status alterations followed by visual loss; these symptoms completely recovered within a few days. [ncbi.nlm.nih.gov]

  Diplopia charting All patients were assessed for diplopia postoperatively and charted. Preoperatively three patients had symptomatic binocular diplopia. Diplopia resolved in all three patients postoperatively between 4 th day and 2 nd week. [amsjournal.com]

  Limitation of ocular movements resulting in binocular diplopia (double vision) may be due to direct involvement of the extraocular muscles, interference with their mechanisms of action, or dysfunction of the third (oculomotor), fourth (trochlear), or [accessmedicine.mhmedical.com]

  Clinical History A 7-year-old female patient presented with left sided painless proptosis and diplopia, developing over the last 3-4 months. Ophthalmologic examination revealed left sided papilledema and loss of vision. [eurorad.org]

  After surgery, exophthalmos was completely resolved, but diplopia showed no improvement. [thejns.org]

• Hemianopsia

  The following day (60 hours post procedure) the patient’s symptoms showed marked improvement, with mild persistent right hemianopsia that was improving every day according to the patient. [ajnr.org]

  Homonymous hemianopia or hemianopsia These are medical terms which imply that a visual field defect (blind area) affects the same half of each eye, either on the right or left side. [web.archive.org]

  Hemianopsia, cortical blindness and ophthalmoplegia may be present. The ERG can show reduced b-wave amplitudes and VEPs may be absent. [disorders.eyes.arizona.edu]

  Properties of the regained visual field after visual detection training of hemianopsia patients. Restorative Neurology and Neuroscience. 2008; 26 (4–5):365–375. [ PubMed ] Bergsma DP, van der Wildt GJ. [ncbi.nlm.nih.gov]

• Esotropia

  […] peripheral nerve containing connective tissue and an anastomotic vascular network epithalamus dorsal posterior subdivision of the diencephalon generally considered to include the habenula, the pineal body, and the epithelial roof of the third ventricle esotropia [strokecenter.org]

• Aggressive Behavior

  As these lesions can arise near the paranasal sinuses, maxillae, and frontal bone and demonstrate expansile and locally aggressive behavior, they may produce morbidity through localized mass effects [ 4 ]. [karger.com]

• Seizure

  The patient had a brief complex seizure during angiography. Following the procedure, she experienced TCB. During this time, an electroencephalogram (EEG) showed seizure activity. [ncbi.nlm.nih.gov]

  Visual loss occurred during seizures and improved with anticonvulsant medication. [journals.lww.com]

• Aphasia

  […] impairment of language production ( non-fluent aphasia ) sparing repetition due to a lesion in the anterior extrasylvian region (prefrontal and medial frontal cortex ) transcortical sensory aphasia impairment of language comprehension ( fluent aphasia [strokecenter.org]

  Patients with MMD who initially present with anterior circulation involvement may additionally proceed to exhibit posterior circulation involvement as well. 2 Anterior circulation ischemia can present with headaches, motor weakness, and aphasia, whereas [ahajournals.org]

  He suffered two consecutive strokes at the age of 52, the first in the left parieto-temporo-occipital cerebral area, which initially produced right hemianopia, hemiplegia, and transcortical sensory aphasia, which receded rapidly except for the hemianopia [jneurosci.org]

  Alzheimer's disease and Lafora disease, show as a marker, an atrophy of the grey matter of the cerebral cortex. [70] Other diseases of the central nervous system include neurological disorders such as epilepsy, movement disorders, and difficulties in speech ( aphasia [en.wikipedia.org]

• Neglect

  Visual Neglect This is characterized by the inability or impaired perception of visual information, usually on one side of the body, due to disturbances with attention mechanisms in the presence of normal acuity. [web.archive.org]

  The role of these different components in the generation of implicit and explicit learning is unclear; however, it seems unlikely that any given component can be neglected. [go.galegroup.com]

  […] simultaneous stimulation (DSS) ability to detect two stimuli applied simultaneously to opposite sides of the body; for tactile DSS, if a patient is able to identify which side is being touched when each side is touched individually, but extinguishes or neglects [strokecenter.org]

  None exhibited visual or other forms of neglect, as determined through a thorough neurological and neuro-ophthalmological exam (supplemental Table 1, available at www.jneurosci.org as supplemental material). [doi.org]

  Fresnel prisms improve visual perception in stroke patients with homonymous hemianopia or unilateral visual neglect. Neurology. 1990; 40 (10):1597–1599. [ PubMed ] Roufs JA. Dynamic properties of vision - 1. [ncbi.nlm.nih.gov]

• Agitation

  There is complete lack of responsive interaction beyond irritability and agitation while motor function is limited to involuntary responses. Two individuals have lived into the second decade of life. [disorders.eyes.arizona.edu]

  More specifically, (i) echolalia, (ii) agitation, and (iii) phases of mutism are present in the patient's behavior. The origin of the visual deficit is not explicitly reported, but crucially there is evidence that blindness run in the family. [frontiersin.org]

• Confabulation

  1 complete absence of visual awareness Type 2 residual awareness of "feeling" or "knowing" of the presented visual stimuli Associated syndromes Anton-Babinski syndrome 3 bilateral cortical blindness visual anosognosia (denial of vision loss) visual confabulation [radiopaedia.org]

  When they are unaware of the extent of visual loss (often confabulating their responses), the clinical presentation is termed “Anton syndrome.” Etiologies of cortical blindness are numerous and diverse. [medlink.com]

  Confabulation may be the most frequently indicated "less common" effect. In the case of confabulation, someone gives false information while maintaining the belief that it is the truth. [en.wikipedia.org]

The first step to diagnose cortical blindness is to establish that vision loss is not a result of eye dysfunction. A person with healthy eyes is expected to have a normal pupil reflex. Asking the patient to describe an object found in the room's surroundings will reveal their inability to describe it or distinguish vital characteristics such as shapes and dimension. The presence of visual hallucinations can further point to the direction of a neurologically-induced case of blindness rather than an ocular one.

Fundoscopy is expected to be normal in patients with cortical blindness. A computerized tomography scan may reveal irregularities on the occipital lobe, depending on the cause of the condition.

Another useful diagnostic tool is the electroencephalogram (EEG). Patients with cortical blindness exhibit slow focal waves, a 10-Hz rhythm irrespective of eye opening and closing, as well as a total absence of alpha rhythm.

The Anton-Babinski syndrome is diagnosed upon clinical examination, when the patient displays inability to discern objects or people around them, but at the same time insists that their vision is intact. Riddoch syndrome is also diagnosed with the clinical examination, since the patient will be able to see a moving finger, hand or person, but will be unable to describe an object that is not in motion.

• Gliosis

  Cardiac arrest usually leads to generalised brain anoxia or to focal neurological abnormalities, resulting in a variable spectrum of diffuse or multifocal cerebral atrophy due to neuronal loss and cortical and subcortical gliosis or even severe cortical [ncbi.nlm.nih.gov]

  […] occipital cortical high signal intensity lesions more marked on the right side, consistent with nonhaemorrhagic contusions. ( b ) At 1 year after the accident, MRI shows focal bilateral occipital cortical loss, more on the right side, consistent with gliosis [nature.com]

  […] astrocytes, oligodendrocytes, ependymal cells, and microglia glioblastoma multiforme WHO grade IV astrocytoma characterized by hemorrhagic necrosis, endothelial proliferation, ± crossing of the corpus callosum, ring-enhancement on imaging, and poor survival gliosis [strokecenter.org]

Cortical blindness can be caused by many underlying diseases. In some cases it may regress, but in some others the damage is permanent. There is not specific way to treat the condition and every treatment plan should be drawn based on the underlying condition. Neurologists perform therapeutic plans aiming at rehabilitation: contrasting colors and discernible patterns are used to train the eye in order to achieve some degree of visual sense. Patients are advised to live in a house where objects are maintained in the same positions and not moved around; it is believed that seeing the same object continually and being aware of what is and looks like will eventually help the brain re-recognize it visually as well.

Cortical blindness that is not caused by a surgical procedure or a vascular event has a generally favorable prognosis. Young age, absence of comorbidities and cognitive defects constitute good prognostic factors in every age.

Incidents of cortical blindness caused by strokes or other types of embolization are viewed in a more negative light, prognostically speaking; so are patients who exhibit bi-occipital anomalies in a computerized tomography scan. Hypertension, diabetes and speech impairment are signs that indicate a potentially worse outcome. Congenital cortical blindness is up to this point medically irreversible.

Cortical blindness may be congenital or acquired and is a result of many underlying conditions that damage the occipital lobe of the brain through various mechanisms. The most common cause of the disease is an arterial occlusion of the one or both of the posterior cerebral arteries [1]. Cortical blindness can, depending on the cause and severity, be permanent or transient. Conditions that may lead to acquired cortical blindness include:

• Traumatization of the head in the region of the occipital lobe.
• Creutzfeldt-Jakob disease and dementia
• Encephalitis
• Lesions of the primary visual cortex
• Anticonvulsants administered for the treatment of epilepsy
• Eclampsia [2] and pre-eclampsia [3] [4]
• Administration of contrast agent during angioscopy [5]

A distinct type of cortical blindness is the Riddoch syndrome. It is caused by lesions that are located in the visual cortex and, instead of leading to total blindness, cause inability to see static things. Moving things can be seen by patients but usually without color or extreme detail.

On the other hand, congenital cortical blindness may be a result of congenital structural defects of the occipital lobe or traumatization, perinatal ischemia and stroke and CNS inflammation.

Temporary cortical blindness has been observed after the performance of procedures such as an angiography, aortography and myelography [6]. Data have showed that the incidence of the condition post cerebral angiography was approximately 1% [7], whereas a vertebral angiography in associated with higher risk of developing temporary cortical blindness [8].

The pathophysiological mechanism leading to an incident of cortical blindness absolutely depends on the underlying cause. Surgical procedures performed on the heart are an important cause, since arterial clamping may disrupt blood flow to the brain and, in particular, the occipital lobe [9], a cerebral hemorrhagic event may occur [10] and embolism is also a possibility; the latter includes clots, as well as fat and air emboli [11]. The calcarine cortex may also be subject to substantial hypoperfusion, leading to death during the operation [12].

In cases of angiography-induced cortical blindness, it is believed that the contrast material may cause significant hypotension and blood flow reduction to the brain, vasospasm or disrupt the blood-brain barrier [13].

Cortical blindness cannot be prevented, as it is a complication of a plethora of other diseases. However, people who suffer from conditions likely to lead to cortical blindness, such as coagulopathies and atherosclerosis, are advised to adhere to their doctor's advice and recommendations in order to better control them.

Vision comprehensively requires two major structures in order to be normal: the eyes and the occipital lobe of the brain. Blindness or any type of vision distortion can be a result of damage, either to the eye or to the brain. Cortical blindness and cortical visual impairment (CVI) are distinguished from each other based on the degree of the resulting disability: cortical blindness involves complete vision loss, whereas CVI implies a partial vision loss. Both conditions are categorized under "neurological visual impairment" which suggests that vision problems originate from the occipital lobe of the brain, in contradistinction to ocular visual impairment, where the damage lies in the eye itself.
Cortical blindness can be congenital, due to perinatal ischemia and subsequent stroke, meningitis or encephalitis, or it can be acquired [1]. Acquired cortical blindness is also a result of brain ischemia (stroke or heart surgery). The condition may result in permanent or temporary vision loss. An interesting phenomenon is the Anton-Babinski syndrome, which involves the total unawareness by the patients that they have lost their vision, despite any evidence that proves otherwise.

Cortical blindness (CB) is the loss of vision caused by damage to the brain, rather than the eyes themselves. A person may be born with cortical blindness; that is the congenital disease type. Other people may develop CB during the course of their lives and suffer from what is called the acquired disease type.

A child may be born with CB as a result of decreased blood flow to the brain during childbirth, head traumatization prior to birth and inflammation of the brain. On the other hand, people who develop the condition later in life, do so as a result of various conditions that damage the occipital brain lobe: the part of the brain that lies in the back of the skull and is responsible for interpreting visual information collected by the eyes. Strokes, decreased blood flow to the occipital lobe during heart surgery, encephalitis, and angiographic contrast material can all lead to cortical blindness.

Cortical blindness has distinct differences from blindness induced by eye problems. The eyes keep their pupil's reflex: when a ray of light is directed to the pupil, it will become smaller. This simple test greatly helps to discern a case of brain-induced blindness from one caused by ocular problems. A doctor will first examine the eyes of a patient to check for the pupil reflex and will then ask the patient to describe various objects or people that can be found in the room. A person with cortical blindness may be completely unable to describe them, or may be unable to discern dimensions and shapes.

CB is diagnosed with the clinical examination, with a brain CT that may reveal abnormal findings and an EEG, that can also help to corroborate the suspicion of blindness due to brain damage.

The condition may be temporary or permanent, always depending on the underlying disease. Although there is no particular way to treat this condition, visual exercises with contrasting shapes and patterns are recommended, in order to stimulate and re-train the brain to interpret visual information.

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