Neurological Disorder - Mental Functioning

Mental Functioning

A neurological examination can to some extent assess the impact of neurological damage and disease on brain function in terms of behavior, memory or cognition. Behavioral neurology specializes in this area. In addition, clinical neuropsychology uses neuropsychological assessment to precisely identify and track problems in mental functioning, usually after some sort of brain injury or neurological impairment.

Alternatively, a condition might first be detected through the presence of abnormalities in mental functioning, and further assessment may indicate an underlying neurological disorder. There are sometimes unclear boundaries in the distinction between disorders treated within neurology, and mental disorders treated within the other medical specialty of psychiatry, or other mental health professions such as clinical psychology. In practice, cases may present as one type but be assessed as more appropriate to the other. Neuropsychiatry deals with mental disorders arising from specific identified diseases of the nervous system.

One area that can be contested is in cases of idiopathic neurological symptoms - conditions where the cause cannot be established. It can be decided in some cases, perhaps by exclusion of any accepted diagnosis, that higher-level brain/mental activity is causing symptoms, rather than the symptoms originating in the area of the nervous system from which they may appear to originate. Classic examples are "functional" seizures, sensory numbness, "functional" limb weakness and functional neurological deficit ("functional" in this context is usually contrasted with the old term "organic disease"). Such cases may be contentiously interpreted as being "psychological" rather than "neurological". Some cases may be classified as mental disorders, for example as conversion disorder, if the symptoms appear to be causally linked to emotional states or responses to social stress or social contexts.

On the other hand, dissociation refer to partial or complete disruption of the integration of a person’s conscious functioning, such that a person may feel detached from one's emotions, body and/or immediate surroundings. At one extreme this may be diagnosed as depersonalization disorder. There are also conditions viewed as neurological where a person appears to consciously register neurological stimuli that cannot possibly be coming from the part of the nervous system to which they would normally be attributed, such as phantom pain or synesthesia, or where limbs act without conscious direction, as in alien hand syndrome. Theories and assumptions about consciousness, free will, moral responsibility and social stigma can play a part in this, whether from the perspective of the clinician or the patient.

Conditions that are classed as mental disorders, or learning disabilities and forms of mental retardation, are not themselves usually dealt with as neurological disorders. Biological psychiatry seeks to understand mental disorders in terms of their basis in the nervous system, however. In clinical practice, mental disorders are usually indicated by a mental state examination, or other type of structured interview or questionnaire process. At the present time, neuroimaging (brain scans) alone cannot accurately diagnose a mental disorder or tell the risk of developing one; however, it can be used to rule out other medical conditions such as a brain tumor. In research, neuroimaging and other neurological tests can show correlations between reported and observed mental difficulties and certain aspects of neural function or differences in brain structure. In general, numerous fields intersect to try and understand the basic processes involved in mental functioning, many of which are brought together in cognitive science. The distinction between neurological and mental disorders can be a matter of some debate, either in regard to specific facts about the cause of a condition or in regard to the general understanding of brain and mind.

Moveover, the definition of disorder in medicine or psychology is sometimes contested in terms of what is considered abnormal, dysfunctional, harmful or unnatural in neurological, evolutionary, psychometric or social terms.