Typical causes of this damage are trauma (such as a traffic collision, diving into shallow water, a fall, a sports injury), disease (such as transverse myelitis, Guillain–Barré syndrome, multiple sclerosis, or polio), or congenital disorders (such as muscular dystrophy).Tetraplegia is defined in many ways; C1–C4 usually affects arm movement more so than a C5–C7 injury; however, all tetraplegics have or have had some kind of finger dysfunction. So, it is not uncommon to have a tetraplegic with fully functional arms but no nervous control of their fingers and thumbs. It is possible to have a broken neck without becoming tetraplegic if the vertebrae are fractured or dislocated but the spinal cord is not damaged. Conversely, it is possible to injure the spinal cord without breaking the spine, for example when a ruptured disc or bone spur on the vertebra protrudes into the spinal column. Diagnosis
Classification
Spinal cord injuries are classified as complete and incomplete by the American Spinal Injury Association (ASIA) classification. The ASIA scale grades patients based on their functional impairment as a result of the injury, grading a patient from A to D. This has considerable consequences for surgical planning and therapy. Complete spinal-cord lesions
Pathophysiologically, the spinal cord of a person with tetraplegia can be divided into three segments which can be useful for classifying the injury. First, there is an injured functional medullary segment. This segment has unparalysed, functional muscles; the action of these muscles is voluntary, not permanent and hand strength can be evaluated by the Medical Research Council (MRC) Scale.
As of 2012, there is a consensus that autism spectrum is likely related to problems with interconnectivity among these regions and networks, rather than problems with any specific region or network. Temporal lobe
Functions of the temporal lobe are related to many of the deficits observed in individuals with ASDs, such as receptive language, social cognition, joint attention, action observation, and empathy. The temporal lobe also contains the superior temporal sulcus and the fusiform face area, which may mediate facial processing. It has been argued that dysfunction in the superior temporal sulcus underlies the social deficits that characterize autism. Compared to typically developing individuals, one study found that individuals with so-called high-functioning autism had reduced activity in the fusiform face area when viewing pictures of faces. Mitochondria
ASD could be linked to mitochondrial disease, a basic cellular abnormality with the potential to cause disturbances in a wide range of body systems. A 2012 meta-analysis study, as well as other population studies show that approximately 5% of autistic children meet the criteria for classical mitochondrial dysfunction. It is unclear why this mitochondrial disease occurs, considering that only 23% of children with both ASD and mitochondrial disease present with mitochondrial DNA abnormalities. Serotonin
Serotonin is a major neurotransmitter in the nervous system and contributes to formation of new neurons (neurogenesis), formation of new connections between neurons (synaptogenesis), remodeling of synapses, and survival and migration of neurons, processes that are necessary for a developing brain and some also necessary for learning in the adult brain.