This circuit is part of the motor control circuit in the brain, making it a reasonable place for abnormality in a movement disorder, but again, researchers are still unsure of the role these differences they found play in the disease pathology. Diffusion tensor imaging
Diffusion tensor imaging (DTI) displays physical alterations in the brain that may not be seen on regular MRI. In one study researchers found that some of the patients had abnormalities in their thalamus. However, this does not prove that all patients have abnormalities in their thalamus. Other cases are cited, including a patient who developed a similar paroxysmal dyskinesia after a thalamic infarction, implicating that an abnormality in the thalamus of individuals could contribute to PKD. It is not fully known, however, what role a thalamic abnormality plays in the disease pathophysiology. Diagnosis
Paroxysmal kinesigenic dyskinesia is diagnosed using a strict set of guidelines. These criteria were studied and confirmed by Bruno et al. in a study of 121 individuals with PKD. The age at onset is between 1 and 20 years old. The attacks of involuntary movements last less than one minute and have a known trigger, usually a sudden voluntary movement. For example, if a PKD patient stands up or begins walking after being sedentary for a period of time, or a person goes from a walk to a run, it can trigger an attack. Persons with PKD do not lose consciousness during attacks and have a full memory of the entire attack.
In the United States and other developed countries, the incidence is low, possibly fivefold less than that of schizophrenia. In developing countries, the incidence is substantially higher, especially for the subtype "With Good Prognostic Features". In some of these settings schizophreniform disorder may be as common as schizophrenia. References
External links
Strakowski SM (June 1994). "Diagnostic validity of schizophreniform disorder". Am J Psychiatry. 151 (6): 815–24. doi:10.1176/ajp.151.6.815. PMID 8184991. Clinical Trials in Schizophrenia, Schizoaffective, or Schizophreniform Disorder 
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