Developmental topographical disorientation
Encyclopedia
Developmental Topographical Disorientation, also known as DTD, is caused by the inability to segregate landmarks and derive navigational information from them, navigate through a non-verbal process, or generate cognitive maps. This is a newly discovered cognitive disorder in which patients who do not have brain structural abnormalities, such as lesions, and exhibit symptoms since childhood
Childhood
Childhood is the age span ranging from birth to adolescence. In developmental psychology, childhood is divided up into the developmental stages of toddlerhood , early childhood , middle childhood , and adolescence .- Age ranges of childhood :The term childhood is non-specific and can imply a...

. Not to be confused with healthy individuals who have a poor sense of direction, DTD patients get lost in very familiar surroundings, such as their house
House
A house is a building or structure that has the ability to be occupied for dwelling by human beings or other creatures. The term house includes many kinds of different dwellings ranging from rudimentary huts of nomadic tribes to free standing individual structures...

 or neighborhood, daily. This disorder could stem from a lack of experience in navigation during development
Child development
Child development stages describe theoretical milestones of child development. Many stage models of development have been proposed, used as working concepts and in some cases asserted as nativist theories....

 and could present in different degrees of severity.

Case One

A woman in Vancouver
Vancouver
Vancouver is a coastal seaport city on the mainland of British Columbia, Canada. It is the hub of Greater Vancouver, which, with over 2.3 million residents, is the third most populous metropolitan area in the country,...

, referred to as Pt1, presented with topographical disorientation in absence of any structural lesions. Despite normal cognitive development
Cognitive development
Cognitive development is a field of study in neuroscience and psychology focusing on a child's development in terms of information processing, conceptual resources, perceptual skill, language learning, and other aspects of brain development and cognitive psychology compared to an adult's point of...

, she has never been able to orient with in the environment. Further testing showed that she was able to follow route based, landmark based, and verbal directions to reach a destination in an urban environment. In map based testing, the patient was unable to determine the shortest path between two locations on a map, but was able to follow a route traced on a map. The patient was unable to draw a detailed schematic of her house. Although the number of rooms and their locations were accurate, the spatial scaling was distorted.

Other Cases

F.G. is a normally developed 22 year old male with more severe symptoms than Pt1. He has no medical history of motor, neurological, or cognitive developmental delays or of neurological or psychiatric diseases. He has been unable to find his bearings in an environment since childhood. F.G. is unable to form a cognitive map, identify landmarks, derive verbal instructions used in navigation, retain a previously learned path, or read a map. He is able to accomplish rudimentary navigational tasks, such as those in a virtual environment, by adopting a verbal strategy. F.G. is unable to segregate and identify a landmark in his environment or determine location or directional information from a landmark he recognizes.

Emergent Disorder

Selective topographical disorientation have been in 120 new cases using an online neuropsychological test
Neuropsychological test
Neuropsychological tests are specifically designed tasks used to measure a psychological function known to be linked to a particular brain structure or pathway. Tests are used for research into brain function and in a clinical setting for the diagnosis of deficits. They usually involve the...

.
The participants reported getting lost daily or 1 to 5 times a week in familiar surroundings such as their neighborhood or house and having this difficulty since childhood. They have no other cognitive difficulties that affect daily activities. The test evaluated their object and face recognition ability, landmark recognition, ability to recall directional information, left/right orientation, and ability to reverse a route to return to starting position. The final two tests involved the formation and use of a cognitive map. The test provided objective confirmation of topographical disorientation and preliminary evaluation of different orientation skills. Future research will include in-person testing to further evaluate orientation skills in a real-world environment along with Neuropsychological evaluation
Neuropsychological assessment
Neuropsychological assessment was traditionally carried out to assess the extent of impairment to a particular skill and to attempt to locate an area of the brain which may have been damaged after brain injury or neurological illness...

and structural imaging to rule out cognitive defects.
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