technetium-tc-99m-exametazime and Encephalitis

SPECT/TC con 99mTc-HMPAO en la encefalitis progresiva mediada por anticuerpos anti-GAD.

Topics: Aged; Autoantibodies; Autoantigens; Autoimmune Diseases of the Nervous System; Cerebral Cortex; Diagnosis, Differential; Encephalitis; Fatal Outcome; Female; Glutamate Decarboxylase; Humans; Multimodal Imaging; Neuroimaging; Paraneoplastic Syndromes, Nervous System; Radiopharmaceuticals; Status Epilepticus; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Topics: Adolescent; Autoantibodies; Cerebrovascular Circulation; Encephalitis; Female; Humans; Receptors, N-Methyl-D-Aspartate; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Rasmussen's encephalitis (RE) is a rare, progressive, chronic encephalitis characterised by drug-resistant epilepsy, progressive hemiparesis and mental impairment. It typically involves only one cerebral hemisphere, which becomes atrophic. We present neuroradiological findings in 13 children with RE. MRI was performed in all patients, fluorodeoxyglucose positron-emission tomography (PET) in three, Tc-99m hexamethylpropylenamine oxime single-photon emission computed tomography (SPECT) in two and proton MR spectroscopy ((1)HMRS) in two. MRI showed progression of the hemisphere atrophy, always prevalent in the region primarily involved (13 patients), spread of the abnormal signal in white matter (11) and cortex (10) and progression of atrophy of the head of the caudate nucleus (nine). Associated secondary changes were: atrophy of the contralateral cerebellar hemisphere (in four patients), the ipsilateral hippocampus (in five) and the brain stem (in five). The earliest CT and MRI abnormalities, seen between 1 day and 4 months after the first seizure (in 12 patients examined, nine of whom had MRI) in one cerebral hemisphere included: high signal on T2-weighted images in the cortex (seven patients) and white matter (nine), cortical atrophy usually involving the frontoinsular region, with mild or severe enlargement of the lateral ventricle (eight) and moderate atrophy of the head of the caudate nucleus (seven). Cortical swelling in the early stage of the disease was recognisable only in two patients. PET revealed hypometabolism, SPECT decreased perfusion, and (1)HMRS reduction of N-acetylaspartate in the affected hemisphere. PET and SPECT were usually performed in the late stages and did not provide specific findings. MRI thus demonstrates the progression of RE and may suggest the diagnosis in the early stages, often before the appearance of neurological deficits. Early diagnosis of RE may be crucial for selecting patients for aggressive medical therapy or major surgical interventions such as hemispherectomy.

Topics: Atrophy; Brain; Child; Child, Preschool; Diagnosis, Differential; Disease Progression; Encephalitis; Female; Fluorodeoxyglucose F18; Humans; Infant; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Male; Protons; Radiopharmaceuticals; Retrospective Studies; Technetium Tc 99m Exametazime; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon

At 4 weeks and 8 months following initial symptoms, we performed single-photon emission computed tomography (SPECT) with acetazolamide (ACZ) testing in a patient recovering from acute encephalitis, possibly acute disseminated encephalomyelitis (ADEM). Both regional hypoperfusion at baseline and diminished cerebrovascular reserve were seen after focal hyperintensities had disappeared in magnetic resonance imaging (MRI). The time course of SPECT abnormalities reflected the clinical course more closely than the time course of MRI abnormalities. Thus, persistent cerebral circulatory impairment probably contributed to cognitive and language deficits observed at the subacute stage.

Topics: Acetazolamide; Adult; Brain; Carbonic Anhydrase Inhibitors; Cerebrovascular Circulation; Encephalitis; Humans; Magnetic Resonance Imaging; Male; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

We compared Tc-99m HMPAO brain SPECT and MRI with the clinical findings in a case of a 14-year-old boy with post-infectious cerebellitis.. Tc-99m HMPAO brain SPECT scan showed marked reduction in perfusion to the left anterior lobe, left lateral hemisphere, and left posterior lobe of the cerebellum. The MRI showed a limited region of abnormal signal in the mid posterior left cerebellar hemisphere. Since the patient's overall neurological deficit was characterized by ataxia, nystagmus, head and body titubation, dysmetria, dysdiadochokinesia, loss of normal check, and rebound testing attributed to the involvement of the anterior, lateral, and posterior lobes of the left cerebellar hemisphere, the Tc-99m HMPAO brain SPECT finding correlated better with the extent of functional neurological deficits.. Tc-99m HMPAO brain SPECT may better assess cerebellar signs and symptoms in cerebellitis since the blood flow abnormalities correlated with dysfunction of the cerebellum, whereas the MRI abnormalities did not encompass the scope of the neurological deficits.

Topics: Adolescent; Cerebellar Diseases; Cerebellum; Encephalitis; Humans; Magnetic Resonance Imaging; Male; Radiopharmaceuticals; Respiratory Tract Infections; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Virus Diseases

Neuroradiological examinations are important in the diagnosis of Rasmussen's syndrome (RS), but they frequently result normal in the early phase of the disease. We performed Tc 99m HMPAO SPECT (single photon emission computed tomography) on an 11-year, 5-month-old, right-handed girl, two months since the first seizure. SPECT showed a reduced uptake of HMPAO in the left temporal region despite normal results with magnetic resonance imaging (MRI). After six months, she developed epilepsia partialis continua, neurological signs appeared, and MRI showed cortical atrophy on the left side. SPECT seems to be a useful, inexpensive and diffuse technology able to give information in the early phases of RS useful in the prevention of serious consequences of the disease within a medical therapeutic program (ganciclovir or intravenous immunoglobulins).

Topics: Child; Encephalitis; Epilepsies, Partial; Female; Humans; Radiopharmaceuticals; 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

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

The authors describe a patient with Rasmussen's syndrome detected by grossly abnormal results of Tc-99m HMPAO SPECT brain imaging obtained with a single-headed camera. Results of magnetic resonance imaging and cerebrospinal fluid examinations were normal.

Topics: Brain; Child, Preschool; Chronic Disease; Encephalitis; Epilepsies, Partial; Female; Hemiplegia; Humans; Organotechnetium Compounds; Oximes; Syndrome; Technetium Tc 99m Exametazime; Time Factors; 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: Aged; Brain; Dementia; Encephalitis; Female; Humans; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Five patients with Rasmussen's syndrome (sometimes known as smouldering encephalitis), are presented. This rare form of childhood epilepsy is characterized by intractable partial seizures with progressive neurological and mental impairment. Diagnostic brain biopsy shows the histological changes of active encephalitis, consistent with a viral infection. Although the raised cerebrospinal fluid (CSF) complement and interferon levels seen in some patients support this hypothesis, no infective agent has yet been isolated. All five patients were investigated by transmission computed tomography (CT) of the head, electroencephalography (EEG) and cerebral single-photon-emission computed tomography (SPECT) using 99Tcm-hexamethylpropylenamine oxime (HMPAO) and in addition 123I-amphetamine (IMP) in Patient 1. 99Tcm-HMPAO is now regarded as reflecting cerebral perfusion, whereas the uptake of 123I-amphetamine is more dependent on cell function. In all patients SPECT imaging demonstrated an area of hypoperfusion/hypometabolism which corresponded to the anatomical localization of the epiletogenic foci found by clinical assessment, EEG and CT. In all cases the SPECT study also demonstrated a more extensive area of abnormality than CT, and in the two patients who had sequential studies, alteration in the size of the defect was found which correlated with the patients' changing clinical condition. SPECT imaging in Rasmussen's syndrome may facilitate anatomical localization of the area of pathology, and may demonstrate a changing pattern in cerebral hypoperfusion/hypometabolism. It could also serve as a guide to accurate brain biopsy.

Topics: Amphetamines; Atrophy; Brain; Child; Electroencephalography; Encephalitis; Epilepsies, Partial; Female; Humans; Iodine Radioisotopes; Male; Organometallic Compounds; Oximes; Syndrome; Technetium; Technetium Tc 99m Exametazime; Tomography, Emission-Computed; Tomography, X-Ray Computed

The purpose of the presented study was to determine the diagnostic value of correlated EEG and SPECT findings in patients with CNS-manifestations of AIDS. Ten HIV 1 infected patients had been examined. Diagnoses: meningitis (2 x), lymphoma (2 x), necrotizing encephalitis (1 x), toxoplasmosis (7 x) (Some patients had more than one diagnosis). Unenhanced and Gd-DTPA enhanced MR, 99mTc-HM-PAO SPECT and clinical EEG were compared. In 9/10 patients MR demonstrated intracranial lesions. In one patient with necrotizing encephalitis (not detected by MR), SPECT revealed an inhomogeneous cerebral perfusion. Only lymphoma was hyperperfused. Toxoplasmic lesions-when detectable by SPECT-were hypoperfused. Reduced rCBF was also seen in brain regions not affected directly, but functionally associated to altered areas. EEG revealed diffuse signs such as slowing in patients with brain atrophy, but also in those patients with lesions of basal ganglia and thalamus. Focal signs in the EEG were in concordance with imaging findings in only 2/10 patients. In 4/10 patients foci even adjacent to the cortex - as shown by MR - remained undetected by EEG. One patient with an active toxoplasmosis had sharp waves over the affected region. The parallel application of the three methods as suggested in this paper appears useful not only for scientific purposes. In most cases, this procedure provides relevant diagnostic information. It is recommended for AIDS-patients with CNS manifestations of unknown etiology.

Topics: Acquired Immunodeficiency Syndrome; Adult; Brain; Brain Diseases; Brain Neoplasms; Electroencephalography; Encephalitis; HIV-1; Humans; Lymphoma; Magnetic Resonance Imaging; Male; Meningitis; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; Toxoplasmosis

Selective uptake of the cerebral blood-flow imaging agent 99mTc-hexamethylpropyleneamine oxime (HM-PAO) by Human Herpesvirus 1 (HSV-1) infected cells was investigated in vivo and in vitro. No specific uptake of HM-PAO was observed either in encephalitic rats (by brain scintigraphic imaging or by immunoperoxidase staining/autoradiography of brain sections) or in HSV-1 infected Vero cells.

Topics: Animals; Antiviral Agents; Autoradiography; Brain; Disease Models, Animal; Encephalitis; Female; Herpesviridae Infections; Humans; Immunoenzyme Techniques; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Rats; Rats, Inbred Strains; Simplexvirus; Technetium Tc 99m Exametazime; Vero Cells

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

Topics: Animals; Encephalitis; Humans; Male; Middle Aged; Organometallic Compounds; Oximes; Rats; Technetium; Technetium Tc 99m Exametazime; Tomography, Emission-Computed