Chapter 17 - Clinical applications

Summary

This chapter focuses on how magnetic resonance imaging (MRI) can be used to add weight to clinical diagnosis for adult movement disorders. Some MRI features and minor abnormalities may coexist in patients presenting with movement disorders. Rare heavy metal-associated disorders may cause movement disorders not by direct accumulation in the brain, but by affecting enzymatic pathways involved in basal ganglia metabolism. Extrapyramidal disorders include Parkinsonism, chorea, ballism, myoclonus of cerebral origin, and dystonia. The brain MRI can be normal in all. There are no specific abnormalities associated with the movement disorders of myoclonus, akathisia, tics, and drug-induced movement disorders, and rarely are there abnormalities which are more specific for tremor and ataxia. Post-infective disorders, for example Sydenham's chorea, other post-streptococcal neuropsychiatric disorders, and encephalitis lethargica, usually have normal imaging, although there are very rare reports of symmetrical, transient, T2 hyperintensity in the basal ganglia.