Akinetopsia

From EyeWiki


Disease

Akinetopsia is derived from Greek: a for “not”, kine for “move”, and opsia for “see”. Akinetopsia refers to "motion blindness", which is a higher visual processing disorder from an extra-striate lesion, in which a patient has difficulty specifically perceiving objects in motion with variable severity and rarely complete.[1]This is a very rare condition with only a few reported cases in the literature. There is thought to be two types of Akinetopsia; "Frozen frames" also know as cinematographic vision, and "vanishing objects" as soon as they move.

Zeitraffer phenomenon is another overlapping condition which shares similarities with akinetospia. Zeitraffer phenomenon describes an altered perception fo speed of moving objects, and the patient may describe an illusory experience of slowed motion. This is thought to be related to dysfunction of brain networks responsible for visual perception of speed. [2]

Akinetopsia can occur in conjunction with other higher visual order manifestations or it can occur in isolation. These patients often can no longer rely on their vision and often train their hearing to help estimate distance and interact with other people.[3]

Etiology

Several causes have been described to cause akinetopsia. These include infarction, traumatic brain injury, neurodegenerative disease such as Alzheimer's ( visual variant of Alzheimer's disease/ posterior cortical atrophy), epilepsy, hallucinogen persistent perception disorder (HPPD), and medication adverse effect.[4][5][6][7]

Pathophysiology

Akinetopsia is thought to be associated with damage to the V5 medial temporal (MT) portion of the brain, involving the tempro-parieto-occipital junction. It is mostly secondary to bilateral disease however has been described in unilateral lesions. Visual information is received in the V1-2 visual association cortex, the visuospatial motion is then processed in the V5 (MT) area. Damage to this latter area may lead to inability to perceive or detect motion " Akinetopsia". Based on the involvement of V5 (MT) area "motion center", the problem can be localized to the dorsal stream responsible for the “where”.[1]

Diagnosis

The diagnosis of akinetopsia is made clinically. There are no diagnostic tests or pathognomonic examination findings.

History

Because of the very unique set of symptoms, suspicion for akinetopsia can be high based on history alone. Patients often have very specific complaints, which they may describe as seeing individual“frames in a movie reel” or “stop-action motion” or “like I’m in room with strobe lights”. They may complain that "objects vanish once they move". Rarely, patients may complain of severe visual impairment. History can also help determine the underlying cause. Additional questions to ask the patient include history of head trauma, Alzheimer’s disease, recreational drug use and medications.[3][4][5]

Physical examination

The afferent and efferent portions of the neuro-ophthalmic exam are often intact. A simple task of throwing a ball for the patient to catch might be helpful to detect the patient's inability to perceive motion . [8]Importantly, one should consider examining other higher order visual functions to check for other possible associations such as simulatanagnosia.

Management

Akinetopsia can be a difficult condition to manage. Management depends on the underlying cause. One may consider vestibular and visual rehabilitation which is controversial with no strong evidence. There are currently no approved medications for the treatment of this condition.

References

  1. 1.0 1.1 S. ZEKI, CEREBRAL AKINETOPSIA (VISUAL MOTION BLINDNESS): A REVIEW, Brain, Volume 114, Issue 2, April 1991, Pages 811-824, https://doi.org/10.1093/brain/114.2.811
  2. Ovsiew, F. (2014). The Zeitraffer phenomenon, akinetopsia, and the visual perception of speed of motion: A case report. Neurocase, 20, 269 –272.
  3. 3.0 3.1 J. ZIHL, D. VON CRAMON, N. MAI, SELECTIVE DISTURBANCE OF MOVEMENT VISION AFTER BILATERAL BRAIN DAMAGE, Brain, Volume 106, Issue 2, June 1983, Pages 313–340, https://doi.org/10.1093/brain/106.2.313
  4. 4.0 4.1 Mark Nawrot. Disorders of motion and depth. Neurologic Clinics. 21(3) 2003, Pages 609-629, ISSN 0733-8619, https://doi.org/10.1016/S0733-8619(02)00126-3.
  5. 5.0 5.1 (http://www.sciencedirect.com/science/article/pii/S0733861902001263) Halpern J.H., Lerner A.G., Passie T. (2016) A Review of Hallucinogen Persisting Perception Disorder (HPPD) and an Exploratory Study of Subjects Claiming Symptoms of HPPD. In: Halberstadt A.L., Vollenweider F.X., Nichols D.E. (eds) Behavioral Neurobiology of Psychedelic Drugs. Current Topics in Behavioral Neurosciences, vol 36. Springer, Berlin, Heidelberg
  6. Kengo Maeda,  Yoshiko Sugihara, Tomoyuki Shiraishi. Akinetopsia with achromatopsia due to focal epilepsy. 2019 Apr;67:27-29. doi: 10.1016/j.seizure.2019.03.004. Epub 2019 Mar 6.PMID: 30856459 DOI: 10.1016/j.seizure.2019.03.004
  7. Po-Heng Tsai, Mario F. Mendez. AKINETOPSIA IN THE POSTERIOR CORTICAL VARIANT OF ALZHEIMER DISEASE September 01, 2009; 73 (9) CLINICAL/SCIENTIFIC NOTES First published August 31, 2009, DOI: https://doi.org/10.1212/WNL.0b013e3181b59c07
  8. Nobuko Otsuka-Hirota 1, Haruko Yamamoto, Kotaro Miyashita, Kazuyuki Nagatsuka. Invisibility of moving objects: a core symptom of motion blindnessBMJ Case Rep. 2014 Apr 12;2014:bcr2013201233. doi: 10.1136/bcr-2013-201233