[Neurobiology in panic states]

Research in panic disorder (PD) has highlighted a low biological threshold (lactate infusion). Also, several studies have shown neurophysiological changes with PD patients: increased brain perfusion (Stewart), parahypocampal hyper-perfusion (Reiman) and we reported an increased incidence of epileptiform abnormalities. In order to assess neuroanatomical changes we carried out a study with magnetic resonance imaging (MRI) of P.D. as compared to controls. A prospective study with MRI was done with 13 P.D. patients and 10 controls. The inclusion criteria were outpatients with P.D. according to DSM-III criteria. All subjects (patients and controls) were right handed and between 18 and 40 years of age. Usual exclusion criteria were used. A Signa MR machine of 1.5 telsa (General Electric) was used and images in T1, T2 mode were generated. We found a higher percentage of brain atrophy in patients with PD (64%) than with controls (20%) and the differences reached significance (p-.04-Fisher ex. test). Right temporal lobe horn atrophy was the most common finding in P.D. patients. There were no difference between patients and controls for age, sex and weight. We have found anatomical changes in young P.D. patients. Whether this atrophy found with MRI and physiological changes previously reported are related should assessed further. However, our findings support biological factors in the etiology of PD and stimulates the development of better pharmacological treatments.