technetium-tc-99m-exametazime and Herpes-Simplex

The authors report a 61-year-old man with chronic viral encephalitis and Koshevnikov syndrome occurring 42 months after initial symptom of right hemiparesis. Serial computed tomography of the brain showed changes in the attenuation of the left temporal lobe lesion over time. Magnetic resonance images of the brain showed enlargement of left temporoparietooccipital lobes with cortical gyral enhancement on T1-weighted images following intravenous administration of gadolinium-DTPA. 99mTc-HMPAO single-photon emission computerized tomography showed increased radioactivity and hyperperfusion in the left temporoparietal region with paradoxically decreased local tissue perfusion at the contralateral right hemisphere. Follow-up magnetic resonance images of the brain 4 years later showed atrophy of bilateral cerebral hemispheres. We postulate that a "transcallosal diaschisis" with subsequent degeneration is a possible mechanism. A brain biopsy from the left temporal lobe lesion showed pictures compatible with viral encephalitis probably herpes simplex encephalitis.

Topics: Atrophy; Brain; Brain Diseases; Cerebrovascular Circulation; Chronic Disease; Contrast Media; Corpus Callosum; Encephalitis, Viral; Epilepsia Partialis Continua; Follow-Up Studies; Gadolinium DTPA; Herpes Simplex; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Occipital Lobe; Parietal Lobe; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

This is a case of herpes simplex encephalitis (HSE) examined with 99mTc-ethyl cysteinate dimer (ECD) and 99mTc-hexamethyl propyleneamine oxime (HMPAO) SPECT. Static images obtained with 99mTc-ECD showed a reduced tracer uptake of the temporal lobe but focal hyperactivity using 99mTc-HMPAO. Dynamic images indicated regional increase of cerebral blood perfusion with both tracers. Technetium-99m-ECD had rapid washout from the inflamed tissue, while 99mTc-HMPAO had avid uptake. Hypofixation of 99mTc-ECD leads to failure to detect the characteristic finding of temporal lobe hyperemia in acute HSE.

Topics: Acute Disease; Aged; Brain; Cysteine; Encephalitis, Viral; Female; Herpes Simplex; Humans; Hyperemia; Organotechnetium Compounds; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Technetium-99m-hexamethyl propyleneamine oxime (HMPAO) and 99mTc-ethyl cysteinate dimer (ECD) accumulate in brain tissue in proportion to regional cerebral blood flow in healthy subjects and in patients with a variety of neurological diseases. We report on four patients with herpes simplex encephalitis and the discordance between these two approved cerebral perfusion imaging radiopharmaceuticals.. SPECT images showed unilateral regional increase of 99mTc-HMPAO uptake and decrease of 99mTc-ECD uptake in the affected temporal lobe.

Topics: Brain; Cysteine; Encephalitis, Viral; Female; Herpes Simplex; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Male; Middle Aged; Organotechnetium Compounds; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

To determine the usefulness of single-photon emission CT (SPECT) in the diagnosis of acute Japanese encephalitis (JE).. We examined 10 patients (six men and four women; mean age, 69 years) with viral encephalitis. We divided the cases into two groups: the JE group (n = 4) and the non-JE group (n = 6; two with herpes simplex encephalitis and four with encephalitis of unknown origin). All cases were investigated with 99mTc-hexamethylpropyleneamine oxime (HMPAO) SPECT within 15 days after the onset of symptoms. Two patients in the JE group were also examinated by SPECT at a later stage. In all cases MR imaging was performed after the SPECT study.. In the acute stage, all patients in the JE group showed a marked increase of HMPAO uptake that matched the hyperintense area observed on MR images in the thalami and putamina bilaterally. Follow-up SPECT studies of two patients with JE revealed a decrease of HMPAO deposition in the areas of high uptake. None of the patients in the non-JE group had an increased accumulation of HMPAO in the thalami or the putamina.. SPECT is helpful in differentiating JE from herpes simplex encephalitis and other types of encephalitis. SPECT may be useful as a diagnostic tool in the early stages of JE.

Topics: Acute Disease; Aged; Brain; Diagnosis, Differential; Encephalitis, Japanese; Encephalitis, Viral; Female; Herpes Simplex; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

In herpes simplex encephalitis (HSE), the authors noted an evident dissociation between the 99mTc-ethyl cysteinate dimer (ECD) and 99mTc-d,l-hexamethyl-propylene-amine oxime (HMPAO) single photon emission computed tomographies (SPECTs). The patient was a 5-year-old boy with diffuse type of pontine glioma, which was treated with hyperfractionated radiotherapy. Two weeks after the completion of radiation therapy, a lesion suggesting that of HSE was noted in the right fronto-temporal region on magnetic resonance images. 99mTc-HMPAO SPECT showed an increased accumulation of the tracer in this lesion. On the 99mTc-ECD dynamic SPECT, an exaggerated accumulation of the tracer was noted within 80 s of administration, followed by a rapid drop in the accumulation, resulting in a low accumulation in 10 min. It was assumed that this dissociation was due to the different mechanisms to trap HMPAO and ECD in the brain tissue.

Topics: Brain; Brain Neoplasms; Child, Preschool; Cranial Irradiation; Cysteine; Encephalitis, Viral; Glioma; Herpes Simplex; Humans; Magnetic Resonance Imaging; Male; Metabolic Clearance Rate; Organotechnetium Compounds; Oximes; Pons; Technetium Compounds; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

We studied two patients with herpes encephalitis (HSE) by [99mTc]HMPAO and [123I]iomazenil single photon emission computed tomography. Increased uptake of HMPAO was seen for up to 63 days in the HSE affected brain area. Iomazenil binds to benzodiazepine receptors and can measure neurone loss. Decreased iomazenil uptake was observed a few days after onset, at a time when hyperfixation of HMPAO occurred. Because in HSE neurone loss occurs simultaneously with hyperfixation of HMPAO, it is unlikely that this hyperfixation is caused by increased neuronal activity, as in epilepsy. This suggests that the hyperfixation of HMPAO in HSE occurs in glia and is sustained by inflammation-related hypermetabolism and acidity. The early neurone loss in HSE stresses the importance of immediate antiviral treatment.

Topics: Brain; Encephalitis; Encephalitis Viruses; Female; Flumazenil; Herpes Simplex; Humans; Iodine Radioisotopes; Middle Aged; Organotechnetium Compounds; Oximes; Receptors, GABA-A; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

Two children were diagnosed with viral encephalitis, due to Epstein-Barr virus infection in one case and to herpes simplex virus infection in the other. Tc-99m HMPAO brain SPECT was arranged to detect changes in regional cerebral blood flow (rCBF) secondary to viral encephalitis. During the acute episode, Tc-99m HMPAO brain SPECT showed that the two cases had increased rCBF. After the acute episode, follow-up brain SPECT was arranged 6 months later. The rCBF in one case was restored to normal on the second brain SPECT, and that in the other case was decreased. The child with normal rCBF in the follow-up brain SPECT had better learning ability and intelligence than the other child with decreased rCBF.

Topics: Brain; Cerebrovascular Circulation; Child; Encephalitis, Viral; Female; Herpes Simplex; Herpesviridae Infections; Herpesvirus 4, Human; Humans; Infant; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tumor Virus Infections

Topics: Brain; Encephalitis; Female; Herpes Simplex; Humans; Magnetic Resonance Imaging; Middle Aged; Organotechnetium Compounds; Oximes; Simplexvirus; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Topics: Adult; Brain; Encephalitis; Herpes Simplex; Humans; Male; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Tc-99m HMPAO brain SPECT was performed in a patient who had partial complex seizures for 1 year after successful acyclovir treatment of biopsy-proven herpes simplex encephalitis 2 years earlier. In spite of antiepileptic medications, her seizures were intractable and occurred daily. Tc-99m HMPAO was administered intravenously while she was having subclinical seizures, and brain SPECT demonstrated an area of hyperperfusion in the right temporal lobe medially and in the contralateral cerebellum. This reverse of the crossed cerebellar diaschisis phenomenon in epileptic disorders has not previously been documented.

Topics: Adult; Brain; Cerebellar Diseases; Encephalitis; Epilepsy, Complex Partial; Female; Herpes Simplex; Humans; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Topics: Encephalitis; Epilepsy, Temporal Lobe; Herpes Simplex; Humans; Male; Middle Aged; Organometallic Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed

Single photon emission computed tomographies (SPECTs) by using N-isopropyl-p-[123I-IMP]-iodo-amphetamine (123I-IMP) and 99mTc-hexamethyl propyleneamine oxime (99mTc-HM-PAO) were serially performed in a 70 yrs. old male with herpes simplex encephalitis (HSE), and the chronological changes of accumulations were studied. Accumulations of both 123I-IMP and 99mTc-HM-PAO increased initially, and then decreased with the stage of HSE being advanced. The sequential appearance of the lesion in HSE with 123I-IMP and 99mTc-HM-PAO SPECTs was as same as that reported previously by X-CT; beginning at the temporal lobe with eventually being spread to the occipital and frontal lobe. Furthermore, it was shown that findings of both SPECTs could reflect considerably the clinical features, and the laboratory data in central spinal fluid. Thus, 123I-IMP and 99mTc-HM-PAO SPECTs seemed to be a useful tool in the diagnosis, deciding of whether the treatment was suspended or continued, and clarifying the pathophysiology in HSE.

Topics: Aged; Amphetamines; Brain; Encephalitis; Herpes Simplex; Humans; Iodine Radioisotopes; Iofetamine; Male; Organometallic Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed

Brain perfusion was studied in 14 patients with acute encephalitis by use of 123I-iodoamphetamine or 99mTc-hexamethylpropyleneamine oxime and single photon emission computed tomography (SPECT), the first examination being made 4-11 days after onset of encephalitis symptoms. All 6 patients with herpes simplex virus encephalitis (HSVE) had strongly increased accumulation of radiotracer in the affected temporal lobe; in the remaining 8 results were normal. At the time of the first SPECT conventional CT images were normal in all patients. The SPECT abnormality in HSVE gradually converted over 4-10 weeks from increased tracer accumulation to greatly subnormal accumulation. Brain perfusion SPECT may be helpful in the early diagnosis of HSVE.

Topics: Acute Disease; Adult; Amphetamines; Antibodies, Viral; Diagnosis, Differential; Electroencephalography; Encephalitis; Female; Follow-Up Studies; Herpes Simplex; Humans; Iodine Radioisotopes; Male; Middle Aged; Organometallic Compounds; Oximes; Radionuclide Imaging; Simplexvirus; Technetium; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed