MATERIAL and METHOD: Triple head camera, ultra high resolution fan beam collimators, Tc-HMPAO. Orthogonal and temporal slices are displayed in a discrete color code and four levels of thresholded volumes. The automatic Neurostat algorithm generates 8 Talairach normalized surface views. Population : 127 cases with significant psychiatric comorbidity [mood , behavioral, learning, anxiety, epilepsy (atypical) and personality disorders]; ages: 7-21 (52 % females). Previous medication failure had occurred in over 1/3 of cases. History of Closed Head Injury was present in 18% and Neurotoxic exposure in 29%. A follow up period of at least 6 months was available.

RESULTS: The evaluation considered Global and/or Focal Hemispheric Increases (GHI and / or FHI) or hemispheric Decreases (GHD and / or FHD) . Subcortical Increases (SCI ) and /or Decreases (SCD ) were considered for the cingulate gyrus (anterior and posterior) insula-s (anterior and posterior) striatum (caudate and putamen) thalamus , orbito-frontal cortex (OFC), cerebellum and pons. In general most of the cases with GHI and FHI, whether associated or not with SC changes responded to mood stabilizers/TAD (thymoleptic anticonvulsant drug). When the thalamus was the only SCI, an antidepressant was required. When basal ganglia (caudate head and/or putamen) were the only SCI, patients responded to anxiolytics and /or to a TAD. When the cingulate gyrus or one of the insula-s was involved alone, all cases responded to TAD but often needed also an antidepressant. When more than one subcortical SCI was found, TAD was almost always beneficial. If the thalamus was one of the additional SCI, the addition of antidepressants added to the benefit. When the thalamus increase was in conjunction with GHD , antidepressant therapy was needed with priority in most cases and, subsequently, supplemented by stimulants. In FHD (as often seen post trauma) the status of surrounding areas (increases or decreases) and of the global appearance have determined the therapeutic intervention. In most cases the features detected on Brain SPECT provided a rationale for the clinical manifestations as well as for past medication failures. Most importantly SPECT provided us with a clear direction for medical treatment resulting in a good or excellent response to treatment in 87% of cases.

CONCLUSIONS: While cortical/subcortical abnormalities on brain SPECT are not specific, their presence and patterns have proven to be of clinical relevance in child and adolescent Neuropsychiatry, for explaining symptomatology, previous medication failures and especially for contributing to a tailored therapeutic approach when faced with the consequences of comorbid conditions in a particular patient. This approach increases significantly the efficacy of treatment planning and may decrease the workup duration.