Contrast-enhanced T1 SPGR imaging is crucial to detect small veins in the preoperative diagnosis. Division of the culprit veins is recommended if the diameter is smaller than the VCPF as it provides a better outcome and lower recurrence rate than transposition.
Recent studies in animal models have suggested that the mammalian target of rapamycin (mTOR) signaling pathway is involved in several features of mesio-temporal lobe epilepsy (MTLE), and that its inhibition could have therapeutic interests. However, it remains controversial whether mTOR activation is the cause or the consequence of MTLE. We previously showed in a mouse model of MTLE associated with hippocampal sclerosis that increased neuronal excitability and brain-derived neurotrophic factor (BDNF) overexpression contribute to the development of morphological features of this form of epilepsy. Here, we addressed whether mTOR activation promotes MTLE epileptogenesis via increasing neuronal excitability and/or BDNF expression or rather mediates neuroplasticity associated with hippocampal sclerosis. In mice injected intrahippocampally with kainate (1 nmol), we showed a biphasic increase of phospho-S6 (p-S6) ribosomal protein expression, the downstream product of the mTOR signaling pathway, in the dispersed granule cell layer (GCL) of the dentate gyrus with a second phase lasting up to 6 months. Chronic treatment with rapamycin suppressed p-S6 expression, granule cell dispersion and mossy fiber sprouting, but did not reduce cell loss, BDNF overexpression, glutamic acid decarboxylase (GAD)67 expression or the development of hippocampal paroxysmal discharges. Neuronal inhibition by midazolam (2 × 10 mg/kg, i.p.) abolished the increased expression of p-S6 in the dispersed GCL. Our data suggest that activation of the mTOR signaling pathway results from the increased neuronal excitation that develops in the GCL and may contribute to MTLE morphological changes. However, these data do not support the role of this pathway in the development of MTLE or its inhibition as a therapy for this form of epilepsy.
Nervus intermedius neuralgia is one of the craniofacial neuralgias, which is extremely rare compared with trigeminal or glossopharyngeal neuralgia. Despite its unique symptom, the aetiology remains unclear. We present a case of a surgically treated 36-year-old woman who suffered from paroxysmal stabbing deep-ear pain for over 10 years. Preoperative magnetic resonance imaging demonstrated a vascular loop compressing the root entry zone of the vestibulocochlear nerve between the seventh and eighth cranial nerves, suggesting nervus intermedius neuralgia as a cause of her pain. Surgical exploration revealed that the nervus intermedius was displaced upward by the anterior inferior cerebellar artery. Transposition of the artery from the brainstem relieved the patient’s neurological symptom immediately after the surgery, supporting the hypothesis that nervus intermedius neuralgia could be caused by neurovascular compression.
Ocular neuromyotonia is a rare ocular motility disorder characterized by involuntary contraction of extraocular muscles resulting in paroxysmal diplopia. Although ocular neuromyotonia is reported as a rare complication after radiation therapy, there are a few cases of ocular neuromyotonia in the absence of irradiation. In the reported cases the possibility of vascular compression has been suggested on radiological imaging. The authors report a case of ocular neuromyotonia treated by microvascular decompression of the third cranial nerve, supporting the hypothesis that neurovascular compression may play a role in its pathogenesis. The usefulness of preoperative 3D imaging for microvascular decompression is also discussed.
The purpose of this study was to investigate the relationship between the frequency of outpatient visits and hypertension control as determined from health insurance records. This 9-year cohort study in Japan was based on 518 participants with hypertension who underwent health checkups in 2004. Participants were aged 35-56 years and none had a history of cardiovascular or cerebrovascular disease. All were covered by the same employee health insurer. Mean annual outpatient visit days at a hospital/clinic during the 9-year period were classified within four quartiles (Q1, Q2, Q3, Q4). Uncontrolled hypertension was defined as a systolic blood pressure (BP) ⩾140 mm Hg and a diastolic BP ⩾90 mm Hg. Logistic regression analysis was used to estimate the multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for the prevalence of uncontrolled hypertension in groups Q1, Q2 and Q3 vs. Q4. The median (25th-75th percentile) annual outpatient visit days was 9.4 (4.0-15.5). Uncontrolled hypertension was observed in 62.4% of the participants in 2013. The multivariable-adjusted ORs and 95% CIs for uncontrolled hypertension in Q1, Q2 and Q3 vs. Q4 were 4.03 (2.28-7.12), 1.67 (0.99-2.81) and 1.44 (0.86-2.41), respectively. Uncontrolled hypertension increased significantly as the number of outpatient visits decreased (P for trend <0.001). This tendency was maintained when participants taking antihypertensive agents at baseline were excluded. Our study showed an inverse relationship between outpatient visit frequency and uncontrolled hypertension.
Background A wide variety of radiologic changes occur within and adjacent to the nidus of arteriovenous malformations (AVMs) after stereotactic radiosurgery (SRS). Our objective was to study the magnetic resonance imaging(MRI)-defined changes following photon radiosurgery of AVMs and specifically to correlate the appearance of a perinidal T2 hyperintensity signal with the eventual angiographic obliteration of an AVM nidus in response to SRS treatment. Material and Methods This retrospective study was conducted on 62 patients with brain AVMs who received photon SRS treatments between 2004 and 2017, using either a technique based on a linear accelerator at the Alexandria LINAC Radiosurgery Center in Egypt (21 patients/AVMs) or a technique based on a gamma unit at the Koto Memorial Gamma Knife Center in Japan (41 patients/AVMs). All patients included in the study had serial clinical and radiologic follow-ups for ≥ 2 years after SRS treatments. Results In the combined study series of 62 patients/AVMs treated with photon SRS, the follow-up MRIs revealed that 50 AVMs (80.6%) showed nonvisualized nidus and 12 AVMs (19.4%) showed decreased nidus size. Radiation-induced changes, defined as appearance of perinidal T2 hyperintensities in post-SRS MRIs, occurred in 34 patients (54.8%). Of the 35 patients with available follow-up angiographic studies, 30 AVMs (85.7%) demonstrated complete nidus obliteration at a mean of 36 months (range: 8–66 months) after SRS. Of the 30 AVMs with both MRI evidence of a nonvisualized nidus and angiographic verification of complete nidus obliteration, 20 AVMs (66.7%) were associated with prior MRI evidence of the appearance of a perinidal T2 hyperintensity signal at an average of 12 months (range: 6–45 months) after SRS. Of the five AVMs with both MRI evidence of decreased nidus size and angiographic verification of partial nidus obliteration, four AVMs (80%) showed perinidal T2 hyperintensity signal on post-SRS follow-up MRIs. Lower Spetzler-Martin grade (p = 0.013), smaller AVM volume (p = 0.017), and appearance of post-SRS perinidal T2 hyperintensity signal (p = 0.007) were the statistically significant independent predictors of AVM obliteration. The appearance of perinidal T2 hyperintensity signal in the post-SRS MRIs had a sensitivity of 66.7%, a specificity of 20%, and an overall accuracy of 60% in predicting the eventual obliteration of the AVM nidus. Conclusions The present study may help improve our current understanding of the mechanisms behind the radiation-induced tissue changes following AVM SRS. Because the SRS-induced hemodynamic changes within the AVM nidus initiate the cascade of the subsequent formation of perinidal vasogenic brain edema, the appearance of perinidal high T2 signal in the follow-up MRIs after SRS would be a valuable indicator of the AVM response to SRS. The development of perinidal hyperintensity was the strongest predictive factor of AVM obliteration (p = 0.007), with relatively high sensitivity (66.7%) and accuracy (60%) and fairly low specificity (20%), as a prognostic sign of eventual complete angiographic obliteration of the AVM nidus following SRS.
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