Topographical disorientation is the inability to orient oneself in one's surroundings, sometimes as a result of focal brain damage. This disability may result from the inability to make use of selective spatial information (e.g., environmental landmarks) or to orient by means of specific cognitive strategies such as the ability to form a mental representation of the environment, also known as a

cognitive map A cognitive map is a type of mental representation which serves an individual to acquire, code, store, recall, and decode information about the relative locations and attributes of phenomena in their everyday or metaphorical spatial environment. ...

. It may be part of a syndrome known as

visuospatial dysgnosia Visuospatial dysgnosia is a loss of the sense of "whereness" in the relation of oneself to one's environment and in the relation of objects to each other. Visuospatial dysgnosia is often linked with topographical disorientation. Symptoms The syndro ...

Classification

Topographical disorientation is the inability to find one's way through an environment due to cognitive impairment. Topographical disorientation has been studied for decades using

case studies A case study is an in-depth, detailed examination of a particular case (or cases) within a real-world context. For example, case studies in medicine may focus on an individual patient or ailment; case studies in business might cover a particular ...

patient A patient is any recipient of health care services that are performed by healthcare professionals. The patient is most often ill or injured and in need of treatment by a physician, nurse, optometrist, dentist, veterinarian, or other health ...

s who have selectively lost their ability to find their way within large-scale, locomotor environments. Several dozen case reports of topographical disorientation have been presented over the last century. Studying these people will aid in the understanding of the complex, multi-component behavior of navigation. Topographical disorientation may be a lifelong deficit, it may result from a stroke, or it can occur as part of a progressive illness. Frequently comorbid with this disorder are

hemispatial neglect Hemispatial neglect is a neuropsychological condition in which, after damage to one hemisphere of the brain (e.g. after a stroke), a deficit in attention and awareness towards the side of space opposite brain damage (contralesional space) is obser ...

achromatopsia Achromatopsia, also known as Rod monochromacy, is a medical syndrome that exhibits symptoms relating to five conditions, most notably monochromacy. Historically, the name referred to monochromacy in general, but now typically refers only to an ...

prosopagnosia Prosopagnosia (from Greek ''prósōpon'', meaning "face", and ''agnōsía'', meaning "non-knowledge"), also called face blindness, (" illChoisser had even begun tpopularizea name for the condition: face blindness.") is a cognitive disorder of fa ...

, and Alzheimer's disease.

Developmental

Developmental topographical disorientation (DTD) refers to the inability to orient from

childhood A child ( : children) is a human being between the stages of birth and puberty, or between the developmental period of infancy and puberty. The legal definition of ''child'' generally refers to a minor, otherwise known as a person younger t ...

despite the absence of any apparent brain damage, neurological condition or general cognitive defects. Individuals affected by DTD are unable to generate a mental representation of the environment (i.e. a cognitive map) and therefore unable to make use of it while orienting (a process that usually people go through while orienting). Not to be confused with healthy individuals who have a poor sense of direction, individuals affected by DTD get lost in very familiar surroundings, such as their

house A house is a single-unit residential building. It may range in complexity from a rudimentary hut to a complex structure of wood, masonry, concrete or other material, outfitted with plumbing, electrical, and heating, ventilation, and air ...

or neighborhood, daily. 3% of the sample had DTD in a study of 1,698 Italians aged between 18 and 35 years (to exclude people with cognitive decline). It was more prevalent in males than females, although, in general, males use more complex navigational strategies. The sense of direction was closely related to gender, navigational strategies adopted, and town knowledge.

Egocentric

Egocentric disorientation is marked by the inability to represent the location of objects with respect to self. This is usually due to

lesion A lesion is any damage or abnormal change in the tissue of an organism, usually caused by disease or trauma. ''Lesion'' is derived from the Latin "injury". Lesions may occur in plants as well as animals. Types There is no designated classif ...

s in the posterior parietal lobe. Patients experience no difficulty recognizing or naming people or objects. They are unable to accurately reach for visual objects and are unable to state the relationship between objects and oneself (above, below, left, right, nearer or farther). In a case study presented by Stark and colleagues, a patient named GW described the inability to accurately reach for visual targets despite normal vision. She had no difficulty recognizing and naming objects presented to her, but was unable to point to locations of targets defined by

visual The visual system comprises the sensory organ (the eye) and parts of the central nervous system (the retina containing photoreceptor cells, the optic nerve, the optic tract and the visual cortex) which gives organisms the sense of sight ...

proprioceptive Proprioception ( ), also referred to as kinaesthesia (or kinesthesia), is the sense of self-movement, force, and body position. It is sometimes described as the "sixth sense". Proprioception is mediated by proprioceptors, mechanosensory neuron ...

, or audio input. The loss of an egocentric spatial representation system left her unable to position herself in space. Most indicative of her disability is that she often turned in the wrong direction when greeted by someone who she was not facing.

Heading

Heading disorientation is marked by the inability to represent direction of orientation with respect to external environment. This is usually due to lesions in the

posterior cingulate The posterior cingulate cortex (PCC) is the caudal part of the cingulate cortex, located posterior to the anterior cingulate cortex. This is the upper part of the " limbic lobe". The cingulate cortex is made up of an area around the midline of t ...

. Patients show no signs of visuo-spatial

agnosia Agnosia is the inability to process sensory information. Often there is a loss of ability to recognize objects, persons, sounds, shapes, or smells while the specific sense is not defective nor is there any significant memory loss. It is usually ...

. Patients are able to determine their location using landmarks, but are unable to determine which direction to proceed from those landmarks in order to reach their destination. They are also impaired in map drawing tasks and are unable to describe routes between familiar locations. Takahashi and colleagues presented three cases of focal brain damage to the right retrosplenial region through a

cerebral hemorrhage Intracerebral hemorrhage (ICH), also known as cerebral bleed, intraparenchymal bleed, and hemorrhagic stroke, or haemorrhagic stroke, is a sudden bleeding into the tissues of the brain, into its ventricles, or into both. It is one kind of bleed ...

that caused a loss in sense of direction. All three patients showed normal

visual perception Visual perception is the ability to interpret the surrounding environment through photopic vision (daytime vision), color vision, scotopic vision (night vision), and mesopic vision (twilight vision), using light in the visible spectrum refl ...

, were able to identify familiar buildings and landscapes, were able to determine and remember locations of objects that could be seen from where they were standing, but were unable to recall direction from selective familiar landmarks. Symptoms of topographical disorientation disappeared in all three patients after two months.

Anterograde amnesiac

Anterograde disorientation is marked by the inability to orient in new environments. This is usually due to lesions in the parahippocampus. Patients were able to navigate through and draw maps of environments learned at least 6 months before the damage. Teng and colleagues tested a profoundly amnesic patient who has complete bilateral damage to the

hippocampus The hippocampus (via Latin from Greek , ' seahorse') is a major component of the brain of humans and other vertebrates. Humans and other mammals have two hippocampi, one in each side of the brain. The hippocampus is part of the limbic system, ...

and extensive damage to adjacent structures in the medial

temporal lobe The temporal lobe is one of the four major lobes of the cerebral cortex in the brain of mammals. The temporal lobe is located beneath the lateral fissure on both cerebral hemispheres of the mammalian brain. The temporal lobe is involved in proc ...

. The patient was able to recall the spatial layout of his hometown where he moved away from 50 years ago, before he became amnesic. The patient has no knowledge of his current neighborhood, where he moved to after his injury. The finding indicates that the medial temporal lobe is not needed for the retrieval of spatial maps learned prior to injury. The hippocampus and other surrounding structures are essential for the formation of long-term

declarative memories Declarative may refer to: * Declarative learning, acquiring information that one can speak about * Declarative memory, one of two types of long term human memory * Declarative programming, a computer programming paradigm * Declarative sentence, a ...

, including spatial memories.

Topographagnosia

Landmark

, also known as topographical agnosia and topographagnosia, is marked by the inability to recognize salient environmental stimuli such as landmarks. This is usually due to lesions in the lingual gyrus. Patients are able to draw detailed maps and

visualize ''Visualize'' is a video release by Def Leppard. A compilation of promo videos, interviews, and concert footage. On DVD, it is bundled with '' Video Archive''. It won a 1993 Metal Edge Readers' Choice Award for "Best Home Video."Metal Edge, June ...

places familiar to them before the illness. They can distinguish between classes of buildings, such as house or skyscraper, but are unable to identify specific buildings, such as their own house or famous landmarks. Patients can navigate using strictly spatial information and specific details of landmarks such as house number or door color. C. A. Pallis described a patient, A.H., who presented with

color Color (American English) or colour (British English) is the visual perceptual property deriving from the spectrum of light interacting with the photoreceptor cells of the eyes. Color categories and physical specifications of color are assoc ...

face The face is the front of an animal's head that features the eyes, nose and mouth, and through which animals express many of their emotions. The face is crucial for human identity, and damage such as scarring or developmental deformities may aff ...

and landmark agnosia as a result of a cerebral embolism.

Diagnosis

Topographical disorientation is usually diagnosed with the use of a comprehensive battery of neuropsychological tests combined with a variety of orientation tasks performed by the participants in both virtual and real surroundings. Performance on certain tests can identify underlying

neurological disorder A neurological disorder is any disorder of the nervous system. Structural, biochemical or electrical abnormalities in the brain, spinal cord or other nerves can result in a range of symptoms. Examples of symptoms include paralysis, muscle weakn ...

s and verify the disorientation as a selective impairment.

Brain imaging Neuroimaging is the use of quantitative (computational) techniques to study the structure and function of the central nervous system, developed as an objective way of scientifically studying the healthy human brain in a non-invasive manner. Incre ...

is used to determine regions of

brain damage Neurotrauma, brain damage or brain injury (BI) is the destruction or degeneration of brain cells. Brain injuries occur due to a wide range of internal and external factors. In general, brain damage refers to significant, undiscriminating t ...

, if any. Navigational skills can be assessed by tests pertaining to

memory Memory is the faculty of the mind by which data or information is encoded, stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future action. If past events could not be remembered ...

, visual-perceptual abilities, object recognition,

mental rotation Mental rotation is the ability to rotate mental representations of two-dimensional and three-dimensional objects as it is related to the visual representation of such rotation within the human mind. There is a relationship between areas of the b ...

, imagery abilities, and spatial abilities. More direct testing of navigation involves asking the patient to describe a route, read a map, draw a map, follow a route, or point out landmarks.

Treatment

Treatment for topographical disorientation has been achieved through a case by case basis. Prognosis is largely dependent on the organic cause. Neuropsychological assessment followed by an assessment of unaffected cognitive abilities can be employed in therapy. Treatment for recovering navigational skills requires strengthening unaffected navigational strategies to bypass any defective ones.

References

External links

What It's Like to Feel Lost in Your Own Home

Where to Learn More about DTD and Take some Online Tests
Neurology Agnosia Dementia Stroke