Author: Nitamar Abdala, MD, Radiology Professor, and Carolina Salazar, MD, Radiology Resident
UMDI – Unidade Mogiana de Diagóstico por Imagem, São Paulo, Brazil

History

A 53 year old male patient with acute high intensity headache episodes and syncope (nausea) one month ago, left hemiplegics, and no more associated symptoms, was referred to the hospital. The patient had a history of hypertension with drug control and Dengue Hemorrhagic five years ago. Patients that suffer from Dengue Hemorrhagic can eventually have low blood flow with hypo cerebral perfusion which can cause cerebral infarction like “watershed”, which means, stroke in the frontier areas. Most of these lesions occur between the anterior and median cerebral arteries, as well as in the basal ganglia. Since this patient had an old stroke possibly caused by an ischemic event related to Dengue Hemorrhagic five years ago and moreover the patient still lives in the endemic area, it was suspected that the current symptoms could be related to the cerebral hypo perfusion.

Diagnosis and comments

CT data acquired with the first SOMATOM Spirit in Brazil shows a lesion detected at right basal ganglia interpreted as encephalic scar from previous event. The current CT Perfusion study shows signals that can be related to hypo perfusion of left basal ganglia.

Fig. 1: Overview of CT perfusion data. Upper left MiP image, Upper right – Blood Flow, Lower left – Blood Volume, Lower right – Time To Peak data.

Fig. 2: MIP image shows an old lesion at right basal ganglia interpreted as encephalic scar from an old stroke (red arrow). And suggested hypoperfused area in the left basal ganglia (orange arrow).

Dengue / Dengue Hemorrhagic Fever
Dengue and dengue hemorrhagic fever (DHF) are acute febrile diseases, found in the tropics, with a geographical spread similar to malaria. Caused by Flavivirus, the disease is transmitted to humans by the mosquito Aedes aegypti. The disease is manifested by a sudden onset of fever, with severe headache, joint and muscular pains (myalgias and arthralgias, severe pain gives it the name break-bone fever), leukopenia and rashes. The dengue rash is characteristically bright red and covers most of the body. DHF also shows higher fever, hemorrhagic phenomena, thrombocytopenia, and hemoconcentration. In around 5 percent of cases there is dengue shock syndrome (DDS) and hemorrhage, leading to death. There is no commercially ready vaccine.

Fig. 3: Perfusion data of Blood Flow [ 3A ] and Blood Volume [ 3B ] from CT Perfusion study shows hypo perfused are a of left basal ganglia (orange arrow) and the old lesion in the right basal ganglia (red arrow).