technetium-tc-99m-exametazime and Encephalitis--Viral

We used Technetium-99m hexamethyl propylene amine oxime single-photon emission computed tomography (HMPAO-SPECT) and magnetic resonance imaging (MRI) to evaluate a 30-year-old woman who developed cerebellar dysfunction after infection with Epstein Barr virus. Although no abnormal findings were evident from a brain MRI, the HMPAO-SPECT revealed increased perfusion in both cerebellar hemispheres. The patient improved without specific treatment. Two sequential HMPAO-SPECTs showed gradually reduced hyperperfusion in the cerebellum, which was correlated with her clinical recovery. We suggest that brain HMPAO-SPECT may thus be useful for identifying acute cerebellitis and predicting its clinical outcome.

Topics: Adult; Cerebellar Diseases; Cerebellum; Cerebral Cortex; Dominance, Cerebral; Encephalitis, Viral; Epstein-Barr Virus Infections; Female; Follow-Up Studies; Gait Ataxia; Humans; Hyperemia; Image Enhancement; Image Processing, Computer-Assisted; Neurologic Examination; Regional Blood Flow; Remission, Spontaneous; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

A healthy 7-year-old girl developed emotional incontinence and amnesia associated with mumps encephalitis. Her neurologic findings markedly improved after treatment of daily injection of thyrotropin-releasing hormone tartrate without any adverse effects. Although magnetic resonance imaging revealed no abnormal findings, the findings of Tc-hexamethylpropyleneamine oxime single photon emission computed tomography demonstrated abnormality of left temporooccipital area thought to be responsible for her symptoms.

Topics: Affective Symptoms; Amnesia; Child; Encephalitis, Viral; Female; Humans; Magnetic Resonance Imaging; Mumps; Technetium Tc 99m Exametazime; Thyrotropin-Releasing Hormone; Tomography, Emission-Computed, Single-Photon

Topics: Arenaviridae Infections; Brain; Child; Encephalitis, Viral; Humans; Magnetic Resonance Imaging; Male; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Two patients, a 3-year-old female and a 1-year-old female, both with a focal encephalopathic process associated with influenza A virus infection, are reported. Both children had neuropsychologic signs suggesting frontal and limbic dysfunction, without disturbances of consciousness or motor function, and had good recoveries. The results of single-photon emission computed tomography and electroencephalography support the finding of reversible impairment of the frontal and limbic areas. Focal reversible encephalopathy has rarely been reported in association with influenza virus infection, although it often provokes diffuse encephalopathies, with a poor prognosis.

Topics: Child, Preschool; Electroencephalography; Encephalitis, Viral; Female; Frontal Lobe; Humans; Infant; Influenza, Human; Orthomyxoviridae; Prognosis; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

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

A 19 year-old man presented with pharyngitis and cervical lymphadenopathy, followed by vomiting and acute cerebellar ataxia. Serologic studies were consistent with a recent Epstein-Barr virus infection. Although contrast-enhanced brain computed tomography and MRI scans were normal, brain perfusion single photon emission tomography (SPECT) examination using 99mTc-HMPAO, performed on the 15th day of illness, showed marked cerebellar hyperperfusion, suggesting a diagnosis of acute post-infectious cerebellitis. After treatment with intravenous human immunoglobulin (IVIg, 2 g kg-1 over three days), progressive neurologic improvement occurred over two weeks. A brain SPECT study repeated after two additional weeks demonstrated a normal perfusion pattern. We conclude that brain perfusion SPECT examination is useful in identifying post-infectious cerebellitis and in monitoring its clinical course. In addition, IVIg may be helpful in treating this condition.

Topics: Adult; Cerebellar Ataxia; Cerebrovascular Circulation; Encephalitis, Viral; Herpesvirus 4, Human; Humans; Immunoglobulins, Intravenous; Magnetic Resonance Imaging; Male; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

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

In a prospective study, regional cerebral blood flow (rCBF) was studied in patients with aseptic meningoencephalitis at 6 wk and 1 yr after onset of disease.. Patients with tick-borne encephalitis ([TBE] n = 73) and meningoencephalitis of other etiology ([non-TBE] n = 56) were investigated with rCBF-scintigraphy (SPECT). SPECT images in the acute phase of disease and at long-term follow-up were analyzed for blood-flow disturbances and their localization in the central nervous system and were correlated to clinical course and outcome.. Decreased rCBF was seen in 50% of patients after 6 wk (TBE 49%, non-TBE 50%) and in 46% (TBE 47%, non-TBE 46%) after 1 yr. The decrease in rCBF was moderate in 18% and 11% at 6 wk and in 8% and 9% at the 1-yr follow-up of TBE and non-TBE patients, respectively. Reduced rCBF was significantly more common among patients with encephalitis than among those with meningitis, and more common in males. The distribution of cerebral flow changes was predominantly patchy or multifocal. At long-term follow-up, improvement in rCBF was seen in 28 of 109 patients (26%), but worsening of decreased rCBF was demonstrated in 19 of 109 (17%). In TBE patients, remaining neurological symptoms at 6 wk of disease were associated with worsening of decreased rCBF at the 1-yr follow-up.. With SPECT, rCBF changes, mostly slight and patchy or multifocal, were detected in patients with aseptic meningoencephalitis. Decreased rCBF was more frequent in patients with moderate-to-severe encephalitis, although the clinical use in predicting long-term outcomes in aseptic meningoencephalitis (e.g., TBE) seems limited.

Topics: Adolescent; Adult; Aged; Brain; Cerebrovascular Circulation; Disease Progression; Encephalitis, Tick-Borne; Encephalitis, Viral; Female; Follow-Up Studies; Humans; Male; Meningoencephalitis; Middle Aged; Radiopharmaceuticals; Reference Values; Regional Blood Flow; Sex Characteristics; Technetium Tc 99m Exametazime; Time Factors; 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

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

To assess the role of regional cerebral blood flow measured by technetium-99m hexamethyl propyleneamine oxime (HMPAO) brain single-photon emission CT (SPECT) in viral encephalitis of children.. Eighteen children diagnosed as having viral encephalitis (12 Epstein-Barr virus, 4 herpes simplex virus, and 2 Japanese B virus) underwent Tc-99m HMPAO brain SPECT and brain MR and/or CT.. During the acute episode, 4 (22%) of the 18 patients had localized abnormality on brain MR and/or CT. Tc-99m HMPAO brain SPECT in the acute phase showed that 17 (94%) of the 18 patients had increased regional cerebral blood flow and 1 (6%) of the 18 children had a normal brain SPECT. Follow-up brain SPECT was performed at least 15 days after the acute episode. In 17 patients with abnormal first brain SPECT, 12 (71%) had normal second brain SPECT and 5 (29%) had decreased regional cerebral blood flow. The group of patients with normal regional cerebral blood flow on the follow-up brain SPECT had a better outcome than the group of patients with decreased regional cerebral blood flow.. (a) The Tc-99m HMPAO brain SPECT was abnormal more often than CT or MR in children with acute viral encephalitis and provided better location. (b) In acute episodes of encephalitis, most patients showed locally increased regional cerebral blood flow. (c) After acute episodes, the regional cerebral blood flow returned to normal in most cases. (d) A normal Tc-99m HMPAO brain SPECT in the subacute phase usually indicates a good clinical outcome (no neurologic defect) 1 year after the acute illness in children with viral encephalitis.

Topics: Adolescent; Brain; Child; Child, Preschool; Encephalitis, Viral; Female; Follow-Up Studies; Humans; Male; Neurologic Examination; Organotechnetium Compounds; Oximes; Regional Blood Flow; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon