Katsuji Tanaka

Sequential MRI, SPECT and PET in respiratory syncytial virus encephalitis.

Abstract We report on a 3-year-old girl with respiratory syncytial virus (RSV) encephalitis manifested by disturbance of consciousness, conjugate eye deviation, anuria, truncal ataxia and intention tremor. T2-weighted magnetic resonance imaging (MRI) showed hyperintense areas in the cerebellar cortex. No lesion was detected in the cerebral cortex, pons or spinal cord. The hyperintense areas in the cerebellar cortex diminished with recovery from the clinical manifestations and had resolved 2 months after onset. The MRI lesions in the cerebellum were considered to be due to oedema. SPECT and positron emission tomography (PET), performed 3 months after onset, disclosed areas of hypoperfusion and hypometabolism at the same sites. One year after onset, MRI showed mild atrophy of the cerebellum. Hypoperfusion on SPECT and hypometabolism on PET remained. Neuroimaging showed that ataxia and tremor in this case were the result of cerebellitis. The patient has no neurological deficit except for mild truncal ataxia. This patient is a rare example of RSV encephalitis.

Efficient isolation of subacute sclerosing panencephalitis virus from patient brains by reference to magnetic resonance and computed tomographic images

Subacute sclerosing panencephalitis virus has been isolated with difficulty from brains of infected patients. More strains are needed for the study of the pathogenesis of this virus. To make the isolation more efficient, we selected portions to be examined from the brains of three patients with reference to findings of repeated magnetic resonance and computed tomographic imaging. Three cell lines susceptible to measles virus field strains were used. In all three cases viruses were isolated most effectively from recent lesions and with Vero cells. Our results suggested that these imaging methods and Vero cells could be used for improvement in the efficiency of isolation of this virus from patient brains.

A case of TUBA1A mutation presenting with lissencephaly and Hirschsprung disease

Gene mutation of tubulin alpha-1A (TUBA1A), a critical component of microtubules of the cytoskeleton, impairs neural migration and causes lissencephaly (LIS). The approximately 45 cases of disease-associated TUBA1A mutations reported to date demonstrate a wide spectrum of phenotypes. Here we describe an 8-year-old girl with lissencephaly, microcephaly, and early-onset epileptic seizures associated with a novel mutation in the TUBA1A gene. The patient developed Hirschsprung disease and the syndrome of inappropriate antidiuretic hormone secretion (SIADH), which had not previously been described in TUBA1A mutation-associated disease. Our case provides new insight into the wide spectrum of disease phenotypes associated with TUBA1A mutation.

A case of cerebral aneurysm associated with complex partial seizures

We report a 20-month-old girl with an unruptured aneurysm of the middle cerebral artery. The initial sign was complex partial seizures. Magnetic resonance angiography showed an aneurysm of the right middle cerebral artery. Cerebral angiography confirmed the presence of a saccular aneurysm. After 3 months, the aneurysm spontaneously thrombosed without neurological deficit. The seizures were controlled by anti-convulsants. The aneurysm was probably near the focus of the complex partial seizures. This is a rare case of a childhood cerebral artery aneurysm that first manifested itself by complex partial seizures.

Twelve-year-old girl with intracranial epidural abscess and sphenoiditis

We report the case of a 12-year-old girl with an intracranial epidural abscess and sphenoiditis. Although she had no history of sinusitis, she developed acute severe headache, fever, and vomiting. Emergent CT and MRI showed a spherical space-occupying lesion of diameter 3 cm in the right cranial fossa with rim enhancement. The lesion was thought to be an epidural abscess adjacent to the right sphenoiditis. On the basis of the MRI findings, we performed emergent surgery to drain the abscess and sinusitis because of severe and rapidly worsening headaches. The patient showed great improvement the day after the operation. Intravenous antibiotics were administered for 8 days. She has completely recovered, with neither sequelae nor recurrence at 7 months after the operation. We believe that this report will be a useful reference for cases of acute onset headache and may be helpful in diagnosis and treatment decisions for severe sinusitis-related intracranial abscess in childhood.

RELATION OF THE ENHANCEMENT OF ENTORHINAL TETANIC RESPONSES BY 50-HZ AMYGDALA STIMULATION TO THE PROGRESSION OF KINDLING IN THE RAT

We recorded entorhinal tetanic responses to 50-Hz kindling stimulations applied at the amygdala in conscious rats, which produced facilitation and depression during the train pulses, in order to analyze the relationship of the changes in the tetanic responses to the development of both after-discharges (ADs) and behavioral seizures. Facilitation was always produced in the earlier tetanic responses and was followed by depression which reached a quasi-steady level in the later tetanic responses during each kindling stimulation. To estimate the changes in magnitude of the excitatory synaptic activation in the tetanic responses, with reference to the development of seizure stages, tetanic responses which produced the same behavioral seizure stage in each rat were averaged and the area between the negative (excitatory) potentials and the baseline of the averaged tetanic response was measured in terms of mV x ms. Magnitudes of the averaged negative components were significantly enhanced with an increase in the order of seizure stages in eight rats (P < 0.01). In addition, the mean magnitude of the averaged negative components had a linear correlation (r = 0.95, P < 0.05) with the mean AD duration with reference to the order of seizure stages in the eight rats. The magnitude of the positive (inhibitory) component in the averaged tetanic responses was also measured and found to decrease with an increase in the seizure stages (P < 0.01). The magnitude of the negative component in the test responses to single (0.3 Hz) stimuli just before kindling stimulations also increased with an increase in the order of seizure stages, indicating long term potentiation of the responses by kindling stimulations. We concluded from the results that the enhancement of facilitation of the excitatory synaptic activation and the reduction of the inhibitory synaptic activation in entorhinal tetanic responses by 50-Hz amygdala kindling stimulation is involved in the electrophysiological source of the progression of kindling epilepsy.

Magnetoencephalography in West syndrome

Abstract Background: Localized lesions induce West syndrome (WS), and patients with West syndrome often subsequently develop focal seizures. Methods: We evaluated patients with West syndrome using magnetoencephalography (MEG). Fourteen patients who currently or previously had West syndrome were examined at 3 months to 6 years of age. MEGs were recorded using the 160-channel, whole-head, laying-type MEG system. Equivalent current dipoles were estimated at the time of spikes on the EEG. Results: The patients were classified according to MRI findings. Seven patients were in the focal lesion group (group F) and seven in the non-focal lesion group (group N). Dipoles were distributed over a wide brain area in seven patients (pattern W). Three patients had dipoles distributed over a wide area along with a dense dipole distribution in a specific cortical area (pattern WC). Four patients had a closed dipole distribution in a unilateral cerebral focal area (pattern C). Dipoles were distributed widely over the bilateral cerebral cortex in patients with infantile spasms with hypsarrhythmia. Conclusions: The change in the dipole distribution pattern in the MEG of patients with West syndrome correlated with the seizure type.