Cognitive disorders are medical conditions that compromise the functioning of the brain. These disorders can be genetic and present at birth, the result of traumatic brain injury, the effects of chronic substance abuse, or the result of neurodegenerative diseases such as dementia. Another common form of cognitive disorder is delirium, a disturbance in cognition (refers to the thinking processes in the brain) characterized by confusion, impaired attention,hallucinations and delusions and changes in the arousal state of the person affected. Delirium tends to have a distinct time of onset and tends to reversed in the majority of cases. The causes of delirium include infections, such as meningitis an infection, drug ingestion, or even sleep deprivation.
Two Common Cognitive Disorders: Dementia and Delirium
Both dementia and delirium are thinking disorders which are not diseases in and of themselves; rather they are clusters of symptoms with an underlying trauma, disease process, reaction to an ingested substance or other physiological disturbance causing the symptoms. The symptoms of dementia includedeficits in the areas of attention, memory, language, and/or problem solving. The symptoms of dementia are progressive in nature and dementia is a chronic condition lifelong condition, while the symptoms of delirium appear all at once and then remit overtime so the person returns to a level of functioning close to their prior level, if not completely. Given that dementia, delirium and other disorders of cognition are so similar in their presentation, it is imperative to get an accurate diagnosis because the treatment of the different disorders differs significantly.
The Diagnosis of Disorders of Cognition
The specialists trained to diagnosis cognitive disorders are neurologists and neuropsychologists. Both professionals take a comprehensive history of the medical, psychological, social, and academic history of the patient as well as a mental status evaluation. A neurologist uses diagnostic tools such as brain scans, physical examinations and other tests, which might be either invasive or noninvasive. Neuropsychologists use batteries of neuropsychological tests, such as the executive functioning scales of the Weschler Adult Intelligence Scales, the Bender-Gestalt, or questionnaires to diagnosis disorders of cognition. The tools a neuropsychologist uses are completely non-invasive. While the neurologist or neuropsychologist might be able to provide some initial impressions on the day of an outpatient evaluation, it takes about 7-14 days to receive the results of the assessment and a diagnosis. The doctors usually provides this information to the patient and family at a follow-up appointment so the doctor can answer questions and provide treatment recommendations.
For more information about this topic consider these resources:
Neurology of Cognitive and Behavioral Disorders [Hardcover]by Orrin Devinsky and Mark D'Esposito
Head Cases: Stories of Brain Injury and Its Aftermath [Paperback]by Michael Paul Mason