Primary brain abscess caused by Nocardia otitidiscaviarum.

Diagnosing primary cerebral nocardiosis is difficult. This case report describes a 79-year-old immunocompetent Japanese woman with a primary brain abscess caused by Nocardia otitidiscaviarum (IFM 11321) and reviews the findings of 11 previous patients with N. otitidiscaviarum-induced brain abscesses. Four patients survived, including ours. Beta-lactams were not effective in our patient, and the diagnosis required a pathologic analysis of the surgical specimen. Sulfamethoxazole/trimethoprim (ST) was administered to the patient. On antibiotic susceptibility testing, N. otitidiscaviarum (IFM11321) was found to be resistant to amoxicillin-clavulanic acid, ceftriaxone, cefotaxime, cefepime, imipenem and clarithromycin, but sensitive to amikacin, gentamicin, ST and linezolid. Antimicrobial susceptibility patterns differ among Nocardia species, making species identification important for treatment. Patients with suspected Nocardia infection should therefore be treated empirically with ST and/or amikacin and considered for surgical management.

Rathke's cleft cyst with non-hemorrhagic rupture resulting in alteration of signal intensity for a short period: a case report.

In a case of 23-year-old female with Rathke's cleft cyst (RCC), unusual changes with size and morphology on computed tomography (CT) and magnetic resonance images (MRI) were noted in a short period of 3 weeks after spontaneous rupture. The CT noted that the intracystic isodensity was changed to hyperdensity. And MRI showed not only a decrease in size of the lesion but also changing from hypo- and hyperintensity in T1- and T2-weighted images to hyperintensity in both T1- and T2-weighted images. The intraoperative findings disclosed that the cyst content was milky-like, but not hemorrhagic. We considered that the leakage of cyst content to the cerebrospinal fluid pathway caused not only inflammatory reaction but also waxing and waning of both the cyst size and intralesional protein concentration, which resulted in unusual changing CT and MR appearance. We should take into consideration that the nature of RCC can be altered by not only intracystic hemorrhage but also non-hemorrhagic rupture even for a short period.

[Elastic modulus measured by spherical indentation used toward the clinical application of the brain stiffness].

OBJECTIVE: Palpation of brain stiffness is one of techniques that leads to successful neurosurgical procedures. In order to evaluate brain stiffness quantitatively, we studied the potential clinical applicability of a spherical indenting tactile sensor. METHODS: The sensor had a spherical rigid indenter (diameter=5.0 mm; contact pressure=1.0 gf/mm2), and the indenter was rapidly pushed and pulled at a constant speed by a computer-controlled motor. The pressure-depth hysteresis curve was obtained using the sensor, and the shear elastic modulus (G) was calculated on the basis of the Hertz contact theory. We adopted the G-value at the maximum depth (G_max) as an indicator of brain stiffness. RESULTS: First, to calibrate the sensor, we investigated the elasticity of silicone plates. The optimal settings for clinical application was an indenting speed of 1.5 mm/s and an indenting maximum depth of 2-3 mm. Next, we measured the elasticity of a decompressive site in 7 patients who had been stable for more than 21 days after undergoing decompressive craniectomy. The G_max of the decompressive site was 1.71 ± 0.75 kPa. Finally, we measured the intraoperative brain elasticity in a case of brain tumor with severe brain edema. The transdural elasticity of the edematous brain was G=4.87 kPa, and the direct elasticity of the brain surface decreased to G=4.34 kPa after dura incision. CONCLUSIONS: The spherical indentation method for measuring brain elasticity seems applicable to neurosurgical procedures.

Edema and elasticity of a fronto-temporal decompressive craniectomy.

BACKGROUND: Decompressive craniectomy is undertaken for relief of brain herniation caused by acute brain swelling. Brain stiffness can be estimated by palpating the decompressive cranial defect and can provide some relatively subjective information to the neurosurgeon to help guide care. The goal of the present study was to objectively evaluate transcutaneous stiffness of the cranial defect using a tactile resonance sensor and to describe the values in patients with a decompressive window in order to characterize the clinical association between brain edema and stiffness. METHODS: Data were prospectively collected from 13 of 37 patients who underwent a decompressive craniectomy in our hospital during a 5-year period. Transcutaneous stiffness was measured as change in frequency and as elastic modulus. RESULTS: Stiffness variables of the decompressive site were measured without any adverse effect and subsequent calculations revealed change in frequency = 101.71 ± 36.42 Hz, and shear elastic modulus = 1.99 ± 1.11 kPa. CONCLUSIONS: The elasticity of stiffness of a decompressive site correlated with brain edema, cisternal cerebrospinal fluid pressure, and brain shift, all of which are related to acute brain edema.

Postoperative quality of life outcome and employment in patients undergoing resection of epileptogenic lesions detected by magnetic resonance imaging.

The long-term postoperative improvement of quality of life (QOL) and employment were investigated in patients undergoing resection of epileptogenic lesions detected by magnetic resonance (MR) imaging to identify the associated preoperative factors. Thirty of 47 patients who underwent lesionectomy between 1987-2001 replied to questionnaires. Patients with extratemporal resection outnumbered those with temporal lobe resection. The mean follow-up period was 12.4 +/- 3.7 years. An arbitrary score for quantitatively assessing QOL was assigned. The mean increases in QOL score points were significantly higher in the late childhood onset group than those in the early childhood onset group, and were also significantly higher in the temporal resection group and extratemporal resection of non-dysplastic cortical pathology group than in the extratemporal resection of dysplastic cortical pathology group. Postoperative QOL improvement and occupational status of patients depended on the completeness of seizure control. Resection of lesions detected by MR imaging in patients with intractable epilepsy resulted in effective long-term QOL improvement and postoperative occupational status. Favorable outcome was related mainly to the pathology of the epileptogenic lesions, whether the lesion site was temporal or extratemporal, and the completeness of seizure control.

[Quantitative assessment of the usefulness of MR-fusion Tl-SPECT image in the diagnosis of brain tumor].

201Tl-SPECT (single photon emission computed tomography) had a disadvantage of low spatial resolution with a limited ROI (region of interest) setting. Recently, the diagnosis of brain tumors has been improved by fusion-imaging employing MRI (magnetic resonance imaging) with Tl-SPECT. In order to assess the usefulness of MR-fusion Tl-SPECT quantitatively, we have compared non-fusion (NF) and MR-fusion (MR-F) imaging with Tl-SEPCT in patients with brain tumors. A total of 38 patients (M/F=14/24) hospitalized at our institution during a 5-year period, each with a histologically confirmed brain tumor, were studied. The index of Tl was used for the early ratio (ER), delayed ratio (DR), and retention index (RI), There was no significant difference between NF and MR-F, which were examined using the test-retest method by 2 observers (N&H), but the Pearson's correlation coefficient was higher for MR-F than for NF. The RI value for MR-F was significantly correlated with the WHO histological grading (r=0.605, n=38, p<0.00l). The DR value for MR-F was significantly correlated with MIB-1 index (r=0.464, n=24, p=0.022). We estimated the RI cut-off value for both NF and MR-F in malignancy by ROC analysis. A cut-off value of RI=0.63 and RI=0.70 was good for NF and MR-F, respectively. The likelihood ratio (LR) of RI was higher for MR-F (LR=6.897) than for NF (LR=2.978), suggesting that RI=0.7 for MR-F was suitable for diagnosis of malignant brain tumor. We conclude that MR-fusion Tl-SPECT is better for quantitative analysis of brain tumors than non-fusion Tl-SPECT.

Long-term seizure outcome in patients undergoing resection of lesions detected by magnetic resonance imaging.

The long-term efficacy of resective surgery was investigated in patients with lesions detected by magnetic resonance (MR) imaging. Thirty of 47 patients who had undergone lesionectomy between 1987-2001 were followed up by questionnaire. Patients with extratemporal resections outnumbered those with temporal lobe resections. The mean follow-up period was 12.4 +/- 3.7 years. Outcomes were graded according to Engel's criteria, and an arbitrary seizure outcome score was given for quantitative assessment. The mean seizure outcome scores were significantly lower in the early childhood (less than 3 years) onset group than in the late childhood (3 to 15 years) onset group, and significantly lower in the extratemporal resection of the cortical dysplasia group than in the temporal resection and the extratemporal resection of non-cortical dysplasia groups. This study indicated that lesionectomy based on MR imaging findings in patients with intractable epilepsy achieved effective long-term seizure control, and the outcome was related mainly to the pathology of the epileptogenic lesions and the temporal or extratemporal location.

Supratentorial primitive neuroectodermal tumor in an aged patient--case report--.

An 88-year-old woman presented with a supratentorial primitive neuroectodermal tumor (PNET) manifesting as disturbance of consciousness and left hemiplegia. Magnetic resonance imaging showed a large mass lesion in the right frontotemporal region. She underwent biopsy of the lesion that confirmed the diagnosis of PNET. Her poor condition only allowed chemotherapy with methyl 6-[3-(2-chloroethyl)-3-nitrosoureido]-6-deoxy-alpha-D-glucopyranoside (MCNU), vincristine, and prednisolone to be performed. The patient died approximately 6 months after diagnosis due to enlargement of the tumor. Supratentorial PNET is a rare tumor, especially in adults. Multimodal therapy consisting of gross total or subtotal resection, radiation therapy, and chemotherapy is generally considered necessary for patients with supratentorial PNET. However, the condition of each patient should be considered in determining the therapeutic plan, especially in the case of extremely aged patients, since supratentorial PNET is malignant and long-term survival is rare despite aggressive treatment.

[Evaluation of brain tumors by simultaneous dual isotope SPECT with 201Tl-chloride and 99mTc-MIBI].

Single photon emission computed tomography (SPECT) is useful for detecting brain tumors. In this study, we evaluated the utility of simultaneous dual SPECT with 201Tl-Chloride (Tl) and 99mTc-MIBI (MIBI) for diagnosis of brain tumors. We evaluated 20 cases, including 2 glioblastomas, 7 anaplastic astrocytomas, 2 oligodendrogliomas, 2 anaplastic ependymomas, 2 medulloblastomas, 2 meningiomas, 1 malignant meningioma, 1 pituitary adenoma, and 1 craniopharyngioma. We analyzed the uptake ratio (T/N ratio) of tracers in both Tl and MIBI at max counts/pixels ratio in the region of interest. The T/N ratios in early and delayed images were described as early ratios (ER) and delay ratios (DR), respectively. The retention index (RI) was calculated as the DR/ER ratio. Significant correlations were found between ER and DR for both Tl (DR = 0.797 * ER + 0.359, r = 0.871), and MIBI (DR = 0.961 * ER - 0.191, r = 0.784). Next, we analyzed the correlations between Tl and MIBI SPECT, for ER, DR, and RI. ER values for the two were strongly correlated (r = 0.791), DR values were weakly correlated (r = 0.556), and RI exhibited no correlation between them (r = 0.328). There were no correlations between tumor volume and T/N ratio for the two (ER-Tl; r = 0.0095, DR-TI; r = 0.0050, ER-MIBI; r = 0.036, DR-MIBI; r = 0.254). Lastly no correlation was found between RI-Tl and RI-MIBI (r = 0.328). We discuss the difference in the mechanism of accumulation of two tracers and the significance of simultaneous dual SPECT using them for the differential diagnosis of pituitary tumors, regrowth of oligodendrogliomas, and multidrug resistance of chemotherapy. Dual SPECT with Tl and MIBI appears to be useful for the diagnosis of brain tumor.