[SPECT and PET in neurology].

Both single photon emission computed tomography (SPECT) and positron emission tomography (PET) are helpful in the practice of neurology. Ictal SPECT is useful to determine the origin of focal seizures in the pre-surgical evaluation. In some centers, it is used to predict the likelihood of massive cerebral swelling after stroke and of cerebral infarction after a subarachnoid hemorrhage. It has also been used to study dopaminergic function in parkinsonian syndromes and in the evaluation of dementia. Given its higher resolution and some other factors, PET is more useful in the evaluation of brain tumors, dementia and the parkinsonian syndromes. It is also useful in the presurgical evaluation of epilepsy.