Optic nerve hypoplasia (ONH) is a medical condition arising from the underdevelopment of the optic nerve(s). This condition is the most common congenital optic nerve anomaly. The optic disc appears abnormally small, because not all the optic nerve axons have developed properly. It is often associated with endocrinopathies (hormone deficiencies), developmental delay, and brain malformations. The optic nerve, which is responsible for transmitting visual signals from the retina to the brain, has approximately 1.2 million nerve fibers in the average person. In those diagnosed with ONH, however, there are noticeably fewer nerves. Symptoms
ONH may be found in isolation or in conjunction with myriad functional and anatomic abnormalities of the central nervous system. Nearly 80% of those affected with ONH will experience hypothalamic dysfunction and/or impaired development of the brain, regardless of MRI findings or severity of ONH. Vision
ONH can be unilateral (in one eye) or bilateral (in both eyes), although it presents most often bilaterally (80%). Because the unilateral cases tend to have better vision, they are typically diagnosed at a later age than those with bilateral ONH. Visual acuity can range from no light perception to near-normal vision. Children diagnosed with ONH generally present with vision problems which include nystagmus (involuntary movement of the eyes), which tends to develop at 1 to 3 months and/or strabismus (inability to align both eyes simultaneously), manifested during the first year of life. The majority of children affected experience improvement in vision during the first few years of life, though the reason for this occurrence is unknown.
The DSM-IV criteria for ADHD were, however, tailored towards the type of symptoms that children would show, and might therefore have underestimated the prevalence of ADHD in adults. In 2013, the newer DSM-5 reviewed some of these criteria, with more lenient requirements for the diagnosis, especially in adults, and the age limit for symptoms first arising raised to twelve years. Signs and symptoms
ADHD is a chronic condition, beginning in early childhood that can persist throughout a persons lifetime. It is estimated that 33–66% of children with ADHD will continue to have significant ADHD-related symptoms persisting into adulthood, resulting in a significant impact on education, employment, and interpersonal relationships.Individuals with ADHD exhibit deficiencies in self-regulation and self-motivation which in turn foster problematic characteristics such as distractibility, procrastination, and disorganization. They are often perceived by others as chaotic, with a tendency to need high stimulation to be less distracted and function effectively. The learning potential and overall intelligence of an adult with ADHD, however, is no different from the potential and intelligence of adults who do not have the disorder.Whereas teachers and caregivers responsible for children are often attuned to the symptoms of ADHD, employers and others who interact with adults are less likely to regard such behaviors as a symptom. In part, this is because symptoms do change with maturity; adults who have ADHD are less likely to exhibit obvious hyperactive behaviors.