Dementia is a disorder which manifests as a set of related symptoms, which usually surfaces when the brain is damaged by injury or disease. The symptoms involve progressive impairments in memory, thinking, and behavior, which negatively affects a persons ability to function and carry out everyday activities. Aside from memory impairment and a disruption in thought patterns, the most common symptoms include emotional problems, difficulties with language, and decreased motivation. The symptoms may be described as occurring in a continuum over several stages. Consciousness is not affected. Dementia ultimately has a significant effect on the individual, caregivers, and on social relationships in general. A diagnosis of dementia requires the observation of a change from a persons usual mental functioning, and a greater cognitive decline than what is caused by normal aging. Several diseases and injuries to the brain, such as a stroke, can give rise to dementia. However, the most common cause is Alzheimers disease, a neurodegenerative disorder. The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), has re-described dementia as a major neurocognitive disorder with varying degrees of severity and many causative subtypes. The International Classification of Diseases (ICD-11) also classes dementia as a neurocognitive disorder with many forms or subclasses. Dementia is listed as an acquired brain syndrome, marked by a decline in cognitive function, and is contrasted with neurodevelopmental disorders.
Expanding over subdivision in depth of the clefts for every classification is not necessary because the principles of treatment and technique for correction are the same.There are four categories:

simple constriction rings
constriction rings associated with deformity of the distal part with or without lymphedema
constriction rings associated with acrosyndactyly
uterine amputationPatterson divided the constriction ring associated with acrosyndactyly into three types:

Type I: conjoined fingertips with well-formed webs of the proper depth
Type II: the tips of the digits are joined, but web formation is not complete
Type III: joined tips, sinus tracts between digits and absent websPatterson IThere are simple constriction rings which are strands most commonly around the distal extremities as fingers and toes. In general, the thumb is not likely to be affected by a constriction ring because the fetus typically holds the thumb in tight adduction flexion, making entanglement with strands less likely. These malformations need to be surgically removed which must be executed in different stages and can done by different techniques (see also treatment). Patterson IIThe CRS involves strands which obstruct the lymphatic vessels and thus causing fluid retention, distal of the affected extremity. This utters itself with swollen parts distal of the constriction. Patterson IIIIn this form there is a complex form of syndactyly named acrosyndactyly, the fingers (or toes) were initially separated but due to the constriction they are formed back together. Sometimes multiple fingers can be involved. The distal fusion between digits or toes never initially involves a skeletal coalition. The digits are usually hypoplastic if multiple digits are involved.