Intelligence quotient–adjusted memory impairment is associated with abnormal single photon emission computed tomography perfusion

Cognitive reserve among highly intelligent older individuals makes detection of early Alzheimer's disease (AD) difficult. We tested the hypothesis that mild memory impairment determined by IQ-adjusted norms is associated with single photon emission computed tomography (SPECT) perfusion abnormality at baseline and predictive of future decline. Twenty-three subjects with a Clinical Dementia Rating (CDR) score of 0, were reclassified after scores were adjusted for IQ into two groups, 10 as having mild memory impairments for ability (IQ-MI) and 13 as memory-normal (IQ-MN). Subjects underwent cognitive and functional assessments at baseline and annual follow-up for 3 years. Perfusion SPECT was acquired at baseline. At follow-up, the IQ-MI subjects demonstrated decline in memory, visuospatial processing, and phonemic fluency, and 6 of 10 had progressed to a CDR of 0.5, while the IQ-MN subjects did not show decline. The IQ-MI group had significantly lower perfusion than the IQ-MN group in parietal/precuneus, temporal, and opercular frontal regions. In contrast, higher perfusion was observed in IQ-MI compared with IQ-MN in the left medial frontal and rostral anterior cingulate regions. IQ-adjusted memory impairment in individuals with high cognitive reserve is associated with baseline SPECT abnormality in a pattern consistent with prodromal AD and predicts subsequent cognitive and functional decline

A longitudinal clinical and spect scan study on HIV-infected patients with new onset seizures and no identifiable cause

A thesis submitted to the Faculty of Health Sciences, University of the Witwatersrand, in fulfillment of the requirements for the degree of Doctor of Philosophy Johannesburg 2015New onset seizures associated with HIV infection have been studied. The data investigating new onset seizures in HIV infected individuals have predominantly originated from developed countries and prior to the availability of anti-retroviral therapy. No longitudinal studies have been conducted. The HIV pandemic has its roots in Africa and South Africa currently bears the brunt of the burden. This study sought to evaluate the current profile of HIV infected individuals presenting with new onset seizures in the South African setting, and to follow up patients in whom no cause is identifiable at baseline. Two hundred Black African patients were recruited from the three major teaching hospitals affiliated to the University of the Witwatersrand, Johannesburg. They had clinical assessments and were extensively investigated to determine a cause for the seizure. In the present study the majority of HIV infected patients with new onset seizures had an underlying cause, the most common of which were meningitis and focal brain lesions. Infectious aetiologies predominated; specifically in patients with advanced disease i.e. HIV stages 2 and 3. Tuberculosis and cryptococcal infections were the most frequent. This is consistent with the prevalent infections in our region. Our patients had advanced immune-suppression as evidenced by the mean CD4 count of 167 μμL. HAART coverage was sub-optimal with the majority of HAART-eligible patients not accessing therapy. The predominant seizure type was generalized tonic-clonic. Neuroimaging abnormalities were present in most patients. Fifteen patients with no identifiable cause were enlisted in the long-term study. These patients had repeated clinical assessments; laboratory investigations; MRI and brain SPECT scans. All patients presented with generalized tonic-clonic seizures. Non-specific white matter lesions on MRI; temporal lobe abnormalities on visual SPECT scans and regional cerebral hypo-perfusion on quantitative SPECT scan analysis were common findings. The patients who initiated HAART during the study period improved on laboratory monitoring and on quantitative SPECT analysis. One patient developed HIV associated dementia during follow up. vi New Onset Seizures in HIV infected individuals in whom no cause is identifiable may possibly represent: Early stages of the spectrum of neurocognitive dysfunction seen in HIV infection A precursor for dementia These patients are likely to benefit from the initiation of anti-retroviral therapy.MT201

Cerebral Circulation

Diagnostics and diseases related to the cerebrovascular system are constantly evolving and updating. 3D augmented reality or quantification of cerebral perfusion are becoming important diagnostic tools in daily practice and the role of the cerebral venous system is being constantly revised considering new theories such as that of “the glymphatic system.” This book provides updates on models, diagnosis, and treatment of diseases of the cerebrovascular system