A seizure is defined as an abnormal surge or excess of electrical activity in the brain. This can result in partial or total loss of consciousness, and may cause muscular spasms, twitches, or other types of dyskinesia (disorders of movement). Spasms, twitches, and dyskinesias are not always caused by seizure disorders, however - they may be caused by a wide range of neuromuscular dysfunctions. 

While many people with schizophrenia do seem to have dysfunctions in multiple signaling molecules, excess levels of dopamine have been clearly associated with this disorder. 

The belief that general or innocuous events exist specifically for or relate specifically to an individual is called a delusion of reference. Examples include belief that a billboard or television commercial is attempting to communicate directly to an individual, the ascribing of significance to random coincidences, or the observation of coded signals or signs in the general environment.

The belief that other people can hear one's thoughts is described by the term thought broadcasting. This is a common symptom in schizophrenia. It is differentiated from telepathy in that thought broadcasting, there is a delusion that thoughts can be heard by anyone, while telepathy is generally non-verbal communication between specific individuals, and may be receptive as well as projective. Auditory hallucinations are false perceptions of sounds (or internal thought perceived at emanating from another source), while delusions of persecution can take many forms but generally include a degree of paranoia or feeling of being targeted for harm or attack.

Positive symptoms in schizophrenia are any symptoms of cognitive excess or disordered thinking. These include delusions, such as delusions of grandeur or persecution, hallucinations, and disorganized speech or behavior. 

Depression has been linked with alterations in taste sensation, including decreased sensitivity to sweetness. This may contribute in some part to the high consumption of sweet foods in certain individuals experiencing a depressive episode. None of the other conditions listed have been correlated with alterations in taste receptor function. 

The correct answer is "Anorexia nervosa." This is the correct answer because in this patient, who is a young female, which is the most commonly encountered demographic for eating disorders, she notes that she has been drastically restricting her intake of food, that she has body dysmorphic thoughts (e.g. thinking that she is "too fat" despite that her BMI is 14), and we learn that her BMI is 14. A diagnosis of anorexia can be made if a patient is restricting their eating or drinking intentionally, and/or is participating in purge behavior, and has a BMI less than 17.5, as in this patient. 

Should this patient have presented in an identical manner, but her BMI been greater than 17.5, by definition, the correct answer would be bulimia nervosa. Given her BMI though, bulimia nervosa is not correct. There is no evidence of binge-eating behavior in this patient either, making that answer incorrect.

While generalized anxiety disorder and/or major depressive disorder are often co-morbid in patients with eating disorders, there is not enough evidence in the example to suggest either diagnosis for this patient. 

Patellofemoral syndrome presents as pain in the front of the knee, sometimes caused by wearing down, roughening, or softening of the cartilage under the kneecap. Osgood-Schlatter disease is a syndrome of irritation of the patellar ligament at the tibial tuberosity, characterized by painful lumps just below the knee, most often seen in young adolescents. Legg-Calvé-Perthes syndrome is due to disruption of blood flow to the femoral head, leading to avascular necrosis. Congenital scoliosis is a spinal deformity characterized by the curving of the spine at an angle greater than 10 degrees on radiography.

Osgood-Schlatter syndrome of irritation of the patellar ligament at the tibial tuberosity, characterized by painful lumps just below the knee, most often seen in young adolescents. Risk factors may include overzealous exercise but it's ultimately thought to be caused by adolescent bone growth. Osteosarcoma, the most common bone cancer in adolescent populations, can present with pain and a lump or frank swelling. This is caused by actual tumor growth, not by any ligamentous issue. Osteosarcoma does present frequently in the knee, and must be ruled out before a diagnosis of Osgood-Schlatter disease is made. Slipped capital femoral epiphysis causes pain and reduced movement in the hip, rather than the knee. Osteomalacia is a general softening of the bones caused by a deficiency in vitamin D.

Psoriatic arthritis will often show a pencil-in-cup deformity on x-ray. Osteoarthritis will show joint space narrowing, sclerosis, and osteophytes. Rheumatoid arthritis and juvenile rheumatoid arthritis will both show soft tissue swelling, joint space narrowing, and may show marginal erosions.