Intrahemispheric Symmetry of Brain Perfusion. Part 3. Assessment of Neuropsycological State of Patients Based on SPECT Data

Abstract

The third part of a series of papers deals with the diagnostics and treatment of patients, both military personnel and civilians, who have suffered traumatic brain injury (TBI) and barotrauma due to combat concussion (CC) with the development of post trauma stress disorder (PTSD). The main method for diagnosing neuro-cognitive changes in such patients is neuropsychological testing (NPT). However, based on different types of questionnaires, the NPT results can have significant inaccuracies associated not only with the subjective opinion of doctor, but also with inadequacy, and, sometimes, with deliberate actions of patients. This leads to the need of developing new objective diagnostic techniques that would confirm and refine the NPT results.

The current paper presents the development of the methodology for assessing the neuropsychological state of servicemen with CC-caused mild TBI based on single-photon emission computed tomography (SPECT) data, in particular, based on the analysis of volumetric cerebral blood flow (CBF) and perfusion intrahemispheric symmetry (IHS) in segments of the brain.

The data of 31 patients with moderate TBI due to CC were analyzed. The consequences of TBI should be considered remote, since at the time of their comprehensive examination from 6 to 12 months passed after the contusion. NPT was used to assess the degree of vegetative disorders according to Wayne of psycho-emotional sphere, the severity of symptoms of traumatic brain damage based on the K. Cicerone questionnaire, and the severity of PTSD based on PCL-military tests. SPECT investigation was carried out using 99mTc-hexamethyl-propylene-amine-oxime (^99mTc-HMPAO). The main quantitative criteria for the analysis of SPECT images were volumetric cerebral blood flow (CBF) and intrahemispheric symmetry (IHS) of perfusion in brain segments. Based on the comparison of CBF and IHS in segments of the brain with the NPT data, the highly correlated relationships were obtained that amounted from 0.82 to 0.90. At the same time, for each of NPT tests, 3–4 brain segments could be singled out, where CBF and IHS to the fullest extent reflect the neuro-cognitive state of the patient. It has been shown for the first time that on the basis of objective SPECT data with ^99mTc-HMPAO it is possible to quantify the patient’s neuro-cognitive state. The research results can be recommended for a wider use in departments of radionuclide diagnostics when examining the military personnel with TBI in the aftermath of CC.