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Cortical Visual Loss
Published in Vivek Lal, A Clinical Approach to Neuro-Ophthalmic Disorders, 2023
Patients with Bálint's syndrome often have bilateral hemifield defects, usually affecting the lower quadrants more, and other visuospatial defects such as left hemineglect and astereopsis (376, 422, 423). Smooth pursuit is often impaired. Patients may complain of metamorphopsia, micropsia and macropsia, or visual perseverations such as palinopsia and monocular polyopia.
Nervous system
Published in David Sturgeon, Introduction to Anatomy and Physiology for Healthcare Students, 2018
The occipital lobe is the smallest and most posterior region of the cerebrum. It consists of the primary visual cortex and the visual association area. The former receives visual information from the retina of the eye via the optic nerves and a series of neurons that originate in the lateral geniculate nuclei of the thalamus (see above). The latter interprets this information in relation to past visual experiences and allows us to recognise and understand what we are ‘seeing’. For example, when you see the characters y, e and s, your visual association area recognises that collectively they form the word ‘yes’. The same is true when you recognise a familiar face or differentiate between a tennis ball and a cricket ball. Damage to this area can result in difficulty identifying objects, colours and words and, in some cases, trigger visual hallucinations or recurrent visual disturbances known as palinopsia (Greek for ‘again’ and ‘seeing’).
MRCPsych Paper A1 Mock Examination 4: Answers
Published in Melvyn WB Zhang, Cyrus SH Ho, Roger Ho, Ian H Treasaden, Basant K Puri, Get Through, 2016
Melvyn WB Zhang, Cyrus SH Ho, Roger CM Ho, Ian H Treasaden, Basant K Puri
Explanation: Palinopsia is a reoccurrence or prolongation of visual perception after the stimulus has been removed. Palinopsia is associated with mania, depression and substance dependence. LSD is a hallucinogen that causes this phenomenon.
Transient vision loss: a neuro-ophthalmic approach to localizing the diagnosis
Published in Expert Review of Ophthalmology, 2018
Helen Chung, Jodie M. Burton, Fiona E. Costello
The quality of the visual disturbance also needs to be characterized. Often patients with TVL will describe their vision as ‘blurry,’ which lacks precision. Further questioning is often required, during which time patients may reveal that they cannot see the beginning of words (left homonymous visual field loss), the ends of words (right homonymous vision loss), the center of objects (central scotomas), or the top or bottom of images (superior or inferior altitudinal defects, respectively). Alternatively, patients may report distorted images such that lines appear bent (metamorphopsia) or images appear slightly misshapen or disfigured (metamorphopsia or migraine). Some patients with cortical causes of vision loss report seeing persistent images, referred to as palinopsia. During this part of the history taking, it should be ascertained whether the quality of the vision loss includes positive and/or negative phenomena. Simple, short-lived positive visual disturbances in one hemi-field of vision can indicate occipital lobe seizures, whereas more complicated visual phenomena are commonly reported in migraine. Occasionally, elderly patients with vision loss describe seeing recurrent patterns or figures with Charles Bonnet Syndrome [4].
Neuro-Ophthalmic Literature Review
Published in Neuro-Ophthalmology, 2021
David A. Bellows, Noel C. Y. Chan, John J. Chen, Hui-Chen Cheng, Peter W. MacIntosh, Jenny A. Nij Bijvank, Michael S. Vaphiades, Konrad P. Weber, Sui H. Wong
Visual snow was diagnosed according to the following recently proposed criteria: 1) dynamic, continuous visual snow for more than 3 months; 2) at least two additional visual symptoms among palinopsia, entoptic phenomena, photophobia, and nyctalopia; 3) symptoms not consistent with typical migraine with visual aura; and 4) symptoms not better explained by other disorders or psychotropic drugs. Migraine was diagnosed based on the third edition of the International Classification of Headache Disorders beta version and prior psychiatric diagnoses and medications were also evaluated for.
Palinopsia Accompanied with Migraine Attack After Having Occipital Brain Abscess
Published in Neuro-Ophthalmology, 2019
Yutaro Takayama, Junya Iwata, Akio Kojima
Palinopsia is defined as the persistence of recurrent visual images after the stimulus has been removed.1 This phenomenon arose with various proposed causes as follows: post-geniculate cortical lesions, peripheral lesions of visual pathways, epilepsy, migraine, drugs, trauma, and diffuse cortical pathologies.2–6 We report a rare palinopsia case accompanied with migraine attack after having occipital abscess.