Symptoms of<unk>  injuries vary based on the severity of the injury or how much of the<unk>  is affected. The three categories used for classifying the severity of<unk>  injuries are mild, moderate or severe. Severity of injuries Mild<unk>  injuries Symptoms of a mild<unk>  injury include headaches, confusions, tinnitus, fatigue, changes in sleep patterns, mood or behavior. Other symptoms include trouble with memory, concentration, attention or thinking. Mental fatigue is a common debilitating experience and may not be linked by the patient to the original (minor) incident. Moderate/severe<unk>  injuries Cognitive symptoms include confusion, aggressiveness, abnormal behavior, slurred speech, and coma or other disorders of consciousness. Physical symptoms include headaches that worsen or do not go away, vomiting or nausea, convulsions, abnormal dilation of the eyes, inability to awaken from sleep, weakness in extremities and loss of coordination. Symptoms in children Symptoms observed in children include changes in eating habits, persistent irritability or sadness, changes in attention, or disrupted sleeping habits. Location of<unk>  predicts symptoms Symptoms of<unk>  injuries can also be influenced by the location of the injury and as a result impairments are specific to the part of the<unk>  affected. Lesion size is correlated with severity, recovery, and comprehension.<unk>  injuries often create impairment or disability that can vary greatly in severity. In cases of severe<unk>  injuries, the likelihood of areas with permanent disability is great, including neurocognitive deficits, delusions (often, to be specific, monothematic delusions), speech or movement problems, and intellectual disability. There may also be personality changes. The most severe cases result in coma or even persistent vegetative state. Even a mild incident can have long-term effects or cause symptoms to appear years later. Studies show there is a correlation between<unk>  lesion and language, speech, and category-specific disorders. Wernicke's aphasia is associated with anomia, unknowingly making up words (neologisms), and problems with comprehension. The symptoms of Wernicke’s aphasia are caused by<unk>  to the posterior section of the superior temporal gyrus.<unk>  to the Broca’s area typically produces symptoms like omitting functional words (agrammatism), sound production changes, dyslexia, dysgraphia, and problems with comprehension and production. Broca’s aphasia is indicative of<unk>  to the posterior inferior frontal gyrus of the<unk> . An impairment following<unk>  to a region of the<unk>  does not necessarily imply that the<unk> d area is wholly responsible for the cognitive process which is impaired, however. For example, in pure alexia, the ability to read is destroyed by a lesion<unk> ng both the left visual field and the connection between the right visual field and the language areas (Broca's area and Wernicke's area). However, this does not mean one suffering from pure alexia is incapable of comprehending speech—merely that there is no connection between their working visual cortex and language areas—as is demonstrated by the fact that pure alexics can still write, speak, and even transcribe letters without understanding their meaning. Lesions to the fusiform gyrus often result in prosopagnosia, the inability to distinguish faces and other complex objects from each other. Lesions in the amygdala would eliminate the enhanced activation seen in occipital and fusiform visual areas in response to fear with the area intact. Amygdala lesions change the functional pattern of activation to emotional stimuli in regions that are distant from the amygdala. Other lesions to the visual cortex have different effects depending on the location of the<unk> . Lesions to V1, for example, can cause blindsight in different areas of the<unk>  depending on the size of the lesion and location relative to the calcarine fissure. Lesions to V4 can cause color-blindness, and bilateral lesions to MT/V5 can cause the loss of the ability to perceive motion. Lesions to the parietal lobes may result in agnosia, an inability to recognize complex objects, smells, or shapes, or amorphosynthesis, a loss of perception on the opposite side of the body. Non-localizing features<unk>  injuries have far-reaching and varied consequences due to the nature of the<unk>  as the main source of bodily control.<unk> -injured people commonly experience issues with memory. This can be issues with either long or short-term memories depending on the location and severity of the injury. Sometimes memory can be improved through rehabilitation, although it can be permanent. Behavioral and personality changes are also commonly observed due to changes of the<unk>  structure in areas controlling hormones or major emotions. Headaches and pain can also occur as a result of a<unk>  injury either directly from the<unk>  or due to neurological conditions stemming from the injury. Due to the changes in the<unk>  as well as the issues associated with the change in physical and mental capacity, depression and low self-esteem are common side effects that can be treated with psychological help. Antidepressants must be used with caution in<unk>  injury people due to the potential for undesired effects because of the already altered<unk>  chemistry. Long term psychological and physiological effects There are multiple responses of the body to<unk>  injury, occurring at different times after the initial occurrence of<unk> , as the functions of the neurons, nerve tracts, or sections of the<unk>  can be affected by<unk> . The immediate response can take many forms. Initially, there may be symptoms such as swelling, pain, bruising, or loss of consciousness. Post-traumatic amnesia is also common with<unk> , as is temporary aphasia, or impairment of language. As time progresses, and the severity of injury becomes clear, there are further responses that may become apparent. Due to loss of blood flow or<unk> d tissue, sustained during the injury, amnesia and aphasia may become permanent, and apraxia has been documented in patients. Amnesia is a condition in which a person is unable to remember things. Aphasia is the loss or impairment of word comprehension or use. Apraxia is a motor disorder caused by<unk>  to the<unk> , and may be more common in those who have been left<unk> d, with loss of mechanical knowledge critical. Headaches, occasional dizziness, and fatigue—all temporary symptoms of<unk>  trauma—may become permanent, or may not disappear for a long time. There are documented cases of lasting psychological effects as well, such as emotional changes often caused by<unk>  to the various parts of the<unk>  that control human emotions and behavior. Individuals who have experienced emotional changes related to<unk>  may have emotions that come very quickly and are very intense, but have very little lasting effect. Emotional changes may not be triggered by a specific event, and can be a cause of stress to the injured party and their family and friends. Often, counseling is suggested for those who experience this effect after their injury, and may be available as an individual or group session. It is important to note that the long term psychological and physiological effects will vary by person and injury. For example, perinatal<unk>  has been implicated in cases of neurodevelopmental impairments and psychiatric illnesses. If any concerning symptoms, signs, or changes to behaviors are occurring, a healthcare provider should be consulted.
Brain damage
Nerve injury
Head injury
Central nervous system disease
Stroke recovery
Acquired brain injury
Trauma
Soft tissue injury