Robust regional cerebral blood flow perfusion deficits in relapsing-remitting multiple sclerosis patients with executive function impairment.

OBJECTIVES: Cognitive impairment is present in up to 65% of Relapsing Remitting Multiple sclerosis (RRMS) patients and can be extremely debilitating. Although deficits in episodic memory and processing speed occur more frequently than executive deficits, executive dysfunction tends to have a significant impact on MS patients' ability to generate strategies, think divergently, solve and estimate problems, and reason in abstract terms with substantial negative impacts on activities of daily living. In the present study we investigated perfusion detection rate and pattern, as well as the association between perfusion rates and cognitive dysfunction in cognitively impaired RRMS patients. METHODS: We present findings from 17 cognitively impaired RRMS patients who were evaluated with a comprehensive neuropsychological battery and additionally evaluated by brain perfusion radiopharmaceutical technetium-99m hexamethyl-propylene amine oxime (99mTc HMPAO). RESULTS: RRMS patients had hypoperfusion in several predefined Brodmann areas and lobes of the brain, relatively to demographically matched healthy controls according to an established normative database NeuroGam™. However, we noted blood flow reduction, mainly in the frontal lobes and other related prefrontal areas, involving both hemispheres, but with asymmetric left hemisphere predominance. Moreover, associations between measures of response inhibition, set shifting (executive functions) and severity of hypoperfusion in the left frontal lobes were also established. CONCLUSION: Cerebral hypoperfusion is an integral feature of MS pathology. Executive dysfunction is associated with robust cerebral perfusion deficits in the frontal and prefrontal cortex of cognitively impaired RRMS patients.

Tc-99m Depreotide SPECT/CT depicts myocardial involvement in a case of thrombotic thrombocytopenic purpura.

We report a case of thrombotic thrombocytopenic purpura (TTP) with cardiac involvement, imaged with Tc-99m depreotide. A 56-year-old man presented with fever, hematuria, and chest pain. Laboratory findings (angiopathic hemolytic anemia, thrombocytopenia, and uremia) were suggestive of TTP. Cardiac enzymes were elevated and diffuse left ventricular hypokinesis was demonstrated by echocardiography. Serum rheumatologic and virologic analysis were negative. A Tc-99m depreotide SPECT/CT study showed diffuse uptake in the myocardium, indicating inflammatory reaction to thrombotic/hemorrhagic myocardial damage. We suggest that Tc-99m depreotide imaging may reveal myocardial involvement in TTP; this could prompt further investigation for potential applications in myocarditis of other etiologies.