Thoracic Intra and Extramedullary Capillary Hemangioma with Subacute Clinical Course: A Case Report and Literature Review.

Capillary hemangiomas are benign tumors comprising a lobulated proliferation of capillary vessels frequently located in the soft tissues of the neck and head. Spinal intradural capillary hemangiomas are rare, particularly intramedullary lesions. To our knowledge, only 31 cases of spinal intramedullary capillary hemangiomas have been reported. Here, we describe a rare case of a thoracic capillary hemangioma comprising extramedullary and intramedullary components. A 51-year-old male patient presented with bilateral lower extremity numbness and subsequent paraparesis, sensory disturbance, and bladder-bowel dysfunction with a subacute clinical course. Magnetic resonance imaging revealed a mass lesion with intramedullary and intradural extramedullary components at the Th9-10 vertebrae level and widespread spinal cord edema. Contrast-enhanced computed tomography revealed abnormal vessels on the dorsal spinal cord surface. Spinal angiography revealed a light-stained mass lesion fed by the radiculopial artery from the right Th11 intercostal artery. The tumor was resected en bloc, and the histological diagnosis was a capillary hemangioma. Postoperatively, the spinal cord edema diminished, and the patient was discharged from the convalescent rehabilitation ward. Although intramedullary capillary hemangioma is a rare spinal tumor and its preoperative diagnosis is difficult, it should be considered in the differential diagnosis of spinal intramedullary tumors.

Postoperative Serum C-Reactive Protein and Cerebrospinal Fluid Leakage after Endoscopic Transsphenoidal Surgery.

Objective Postoperative cerebrospinal fluid (CSF) leakage in endoscopic transsphenoidal surgery is a potential risk that requires immediate repair. We investigated the potential of common postoperative hematological examinations for diagnosing postoperative CSF leakage. Methods We retrospectively studied 214 consecutive cases who underwent endoscopic transsphenoidal approach (ETSA; transsellar approach) or extended ETSA (E-ETSA). Patients with postoperative CSF leakage were defined the leak group (group L), and patients without were defined as the nonleak group (group N). Postoperative C-reactive protein (CRP) was compared between the ETSA and E-ETSA groups, and between the N and L groups. Results The values of white blood cell count and CRP 1 to 7 days after surgery were significantly higher in the L group. Especially, CRP was clearly elevated in the L group ( p < 0.001). The CRP value was higher in patients in the N group after E-ETSA than after ETSA ( p < 0.001). CRP increased on the day after surgery but decreased gradually thereafter in patients after ETSA and in the N group. In contrast, CRP value tended to increase gradually after surgery in the L group. In particular, the CRP on the day before the CSF leak was confirmed was clearly higher than on the fifth to seventh days in the N group. Conclusion Elevated CRP after endoscopic endonasal transsphenoidal surgery is a potential marker of CSF leakage.

Glossopharyngeal neuralgia with repeated cardiac syncope: A case report.

Background: Glossopharyngeal neuralgia (GPN) is an uncommon craniofacial pain syndrome. Although rare, it is occasionally associated with cardiac syncope, as vago-glossopharyngeal neuralgia (VGPN). Case Description: We present the case of a 73-year-old man with VGPN misdiagnosed as trigeminal neuralgia. The patient was diagnosed with sick sinus syndrome, and a pacemaker was introduced. However, syncope still recurred. Magnetic resonance imaging revealed a branch of the right posterior inferior cerebellar artery contacting the root exit zone of the right glossopharyngeal and vagus nerves. We diagnosed VGPN due to neurovascular compression and performed microvascular decompression (MVD). The symptoms disappeared postoperatively. Conclusion: Diagnosis of VGPN needs appropriate medical interviews and physical examination. MVD is the only curative treatment for VGPN occurring as a neurovascular compression syndrome.

Analysis of visual field disturbance in patients with sellar and suprasellar lesions: relationship with magnetic resonance imaging findings and sagittal bending of the optic nerve.

PURPOSE: Visual dysfunction due to sellar and suprasellar lesions is thought to be caused by chiasmatic compression and bending of the optic nerve at the entrance of the optic canal. We examined the relationship between visual field impairment and magnetic resonance (MR) imaging. METHODS: This study reviewed 122 consecutive patients with sellar and suprasellar tumors. We have newly devised a simple visual field impairment score (SVFIS) that was divided into 12 areas. SVFIS is classified into four grades as mild (0-3 points), moderate (4-6 points), severe (7-9 points), and most severe (10-12 points) for each eye. We investigated the relationship between SVFIS grades and MR imaging, including the recently reported optic nerve-canal bending angle (ONCBA) and visual acuity. RESULTS: Ipsilateral visual acuity tended to deteriorate with increased SVFIS grade. Larger ONCBA was associated with increased SVFIS grades. Bitemporal hemianopia occurred in the early stage (mild case), but the central visual field within 30° was particularly likely to be impaired. The visual field disturbance progressed clockwise (counterclockwise on the left side) from the upper temporal side. Disorders of the central visual field within 5° were associated with ipsilateral large ONCBA. CONCLUSIONS: The newly developed SVFIS grades are closely associated with indicators of visual pathway impairment on MR imaging, and are useful as indicators of the severity and progression of visual field impairment due to sellar and suprasellar lesions. Disorders of the central visual field within 5° were found to be associated with ipsilateral large ONCBA.

Single-Layer Fascia Patchwork Closure for the Extended Endoscopic Transsphenoidal Transtuberculum Transplanum Approach: Deep Suturing Technique and Preliminary Results.

OBJECTIVE: To describe a single-layer fascia patchwork closure (FPWC) without nasoseptal flap (NSF) and compare postoperative cerebrospinal fluid (CSF) leakage between FPWC using NSF and single-layer FPWC without NSF for the extended endoscopic transsphenoidal transtuberculum transplanum approach. METHODS: Forty-five cases of suprasellar tumor in 42 patients were treated with extended endoscopic transsphenoidal removal, resulting in extensive, high-flow CSF leakage. Following the intradural procedure for treatment of various suprasellar tumors, fascia lata was inlaid subdurally on the cranial base defect and patch-sutured around its entire circumference under endoscope visualization, using an average of 17 stitches. Septal bone or hydroxyapatite plate was used for the hard support material against pulsatile intracranial pressure. NSF was added in the earlier 17 cases. Closure was completed without NSF in the more recent 28 cases when the Valsalva maneuver confirmed watertight closure. Two recent cases required NSF after Valsalva maneuver and were included in the FPWC + NSF group. RESULTS: Postoperative CSF leakage did not occur in the FPWC + NSF group but occurred in 2 patients in the single-layer FPWC group (7.1%) (P = 0.52). There was no significant difference in CSF leakage between single-layer FPWC and FPWC + NSF. The mean suturing time for FPWC was 85.8 minutes, and the shortest was 39 minutes in a recent case (mean, 17 stitches; n = 35, video analysis). CONCLUSIONS: Single-layer FPWC may be a viable technical option for effective skull base reconstruction after the extended endoscopic transsphenoidal transtuberculum transplanum approach.

Thalamic anterior part of the ventral posterolateral nucleus and central lateral nucleus in the genesis of central post-stroke pain.

BACKGROUND: The genesis of central post-stroke pain (CPSP) is important but difficult to understand. We evaluated the involvement of the thalamic anterior part of the ventral posterolateral nucleus (VPLa) and central lateral nucleus (CL) in the occurrence of CPSP. METHOD: Stereotactic thalamotomy was performed on the posterior part of the ventral lateral nucleus (VLp)-VPLa and CL in 9 patients with CPSP caused by deep-seated intracerebral hemorrhage. Computed tomography (CT) did not reveal definite thalamic lesion in 5 patients but did in 4 patients. Electrophysiological studies of these thalamic nuclei were carried out during the surgery. Anatomical studies using CT were performed in another 20 patients with thalamic hemorrhage who had clear consciousness but had sensory disturbance at onset. RESULTS: Neural activities were preserved and hyperactive and unstable discharges (HUDs) were often recognized along the trajectory in the thalamic VLp-VPLa in 5 patients without thalamic lesion. Surgical modification of this area ameliorated pain, particularly movement-related pain. Neural activities were hypoactive in the other 4 patients with thalamic lesion. However, neural activities were preserved and HUDs were sometimes recognized in the CL. Sensory responses were seen, but at low rate, in the sensory thalamus. Anatomical study showed that the thalamic lesion was obviously smaller in the patients with developing pain in the chronic stage. CONCLUSIONS: Change in neural activities around the cerebrovascular disease lesion in the thalamic VPLa or CL might affect the perception of sensory impulses or sensory processing in those thalamic nuclei, resulting in the genesis of CPSP.

Electrical Thalamic Stimulation in the Anterior Part of the Ventral Posterolateral Nucleus for the Treatment of Patients With Central Poststroke Pain.

OBJECTIVES: The effects of thalamic stimulation of the anterior part of the ventral posterolateral nucleus (VPLa) for central poststroke pain (CPSP) and the pain-related electrophysiological characteristics of this structure were investigated. MATERIALS AND METHODS: Nine patients with CPSP manifesting as hemibody pain were enrolled. Stereotactic thalamic VPLa stimulation was implemented, and intraoperative electrophysiological studies on hyperactive and unstable discharges (HUDs) and responses to sensory and electrical stimulation were performed in the sensory thalamus. A preoperative somatosensory-evoked potential (SEP) study was carried out in all nine patients and in eight other patients with localized pain. RESULTS: The patients were classified into two groups: a HUD-dominant group (group H, n = 5) and a sensory response-dominant group (group R, n = 4). HUDs were frequently encountered in the thalamic VPLa in the former group. The total number of HUDs and the number along the trajectory to the VPLa in group H were significantly larger than those in group R. The improvements on the pain numeric rating scale in group H were significantly higher than those in group R two years after surgery. The amplitude ratio of the SEP N20s in the ipsilateral to the contralateral side of CVD lesion in the study group was significantly lower than in the localized pain group. CONCLUSIONS: Adequate and stable pain relief with thalamic VPLa stimulation is obtainable in patients with CPSP who exhibit hyperactivity and electrical instability along the trajectory to this nucleus. Both responders and nonresponders were found to have severe dysfunction of the lemniscal system.

Sagittal bending of the optic nerve at the entrance from the intracranial to the optic canal and ipsilateral visual acuity in patients with sellar and suprasellar lesions.

OBJECTIVE: Visual acuity impairment due to sellar and suprasellar tumors is not fully understood. The relationship between these tumors and disturbance of visual function was examined using preoperative MRI. METHODS: This study reviewed 93 consecutive patients with sellar and suprasellar tumors. Best-corrected visual acuity (BCVA) and visual impairment score (VIS) were used for estimation of visual impairments. Preoperative MR images were examined to obtain several values for estimation of chiasmatic compression. Additionally, the optic nerve-canal bending angle (ONCBA) was newly defined as the external angle formed by the optic nerve in the optic canal and the optic nerve in the intracranial subarachnoid space at the junction, using preoperative sagittal T2-weighted MR images. RESULTS: The mean ONCBA was about the same on the right (44° ± 25°) and the left (44° ± 24°). Sagittal ONCBA was defined as large (> 45°) and moderate (≤ 45°) on each side. Preoperative VIS was found to be significantly worse if the right or left ONCBA (or both) was large (right side: ONCBA large [median 20, IQR 8-30] > ONCBA moderate [median 10, IQR 3-17], p = 0.003, Mann-Whitney U-test; left side: ONCBA large [median 22, IQR 9-30] > ONCBA moderate [median 10, IQR 2-16], p = 0.001). A large ONCBA showed a significant relationship with unfavorable ipsilateral BCVA (> logMAR, 0; right side, p = 0.001, left side, p = 0.001, chi-square test). The ONCBA had a positive correlation with ipsilateral BCVA (right: r = 0.297, p = 0.031; left: r = 0.451, p = 0.000, Pearson's correlation coefficient). Preoperative BCVA was significantly lower on the same side in the large ONCBA group compared with the moderate ONCBA group (right side: large ONCBA 0.169 ± 0.333 [logMAR, mean ± standard deviation] vs moderate ONCBA 0.045 ± 0.359, p = 0.026, Student t-test; left side: large ONCBA 0.245 ± 0.346 vs moderate ONCBA 0.025 ± 0.333, p = 0.000). This visual acuity impairment improved after resection of the tumors. CONCLUSIONS: Sagittal bending of the optic nerve at the entrance from the intracranial subarachnoid space to the optic canal may be related to ipsilateral deterioration of visual acuity in sellar and suprasellar lesions. Sagittal T2-weighted MRI is recommended for preoperative estimation of the optic nerve bending.

Extended endoscopic endonasal resection of craniopharyngioma using intraoperative visual evoked potential monitoring: technical note.

BACKGROUND: To avoid deterioration of visual function, extended endoscopic endonasal transsphenoidal surgery (TSS) for craniopharyngioma was performed with visual evoked potential (VEP) monitoring using light-emitting diodes (LEDs). METHODS: The position of the optic chiasm was carefully evaluated on the preoperative midsagittal magnetic resonance (MR) images. Intraoperatively, direct and sharp dissection of the tumor from the optic chiasm was performed under VEP monitoring with LEDs through extended endoscopic endonasal TSS. If the VEP finding changed and became unstable, the operator were informed and stopped the surgical manipulation for the optic chiasm to recover. After 5-10 min, recovery of VEP findings was checked and the procedure resumed. RESULTS: Extended endoscopic endonasal TSS with VEP monitoring was performed in consecutive 7 adult patients with newly diagnosed suprasellar craniopharyngiomas with maximum diameters of 25-41 mm (mean 33.7 mm). VEPs were stable throughout the surgery in 5 cases, but showed temporary instability and amplitude decrease in 2 cases, although the VEPs had recovered at the end of the surgery. Visual function, evaluated using visual impairment score, was improved after surgery in all patients. Gross total removal was achieved in 5 cases, and subtotal removal (90%) in 2 cases. CONCLUSIONS: Intraoperative VEP monitoring is the only way to test visual function during surgery, and may be important and helpful in extended endoscopic endonasal TSS, which requires direct dissection between the optic nerve and craniopharyngioma under the endoscope.

Combined supra-infrasellar approach to pituitary macroadenoma with oculomotor cistern extension: surgical strategy and experience.

BACKGROUND: Oculomotor cistern extension (OMCE) of pituitary adenoma through the oculomotor triangle may be one of the major characteristics of multi-lobulated adenoma. The OMCE may be hard to remove only through the endonasal approach. METHOD: We applied the simultaneous combined supra-infrasellar approach to remove pituitary adenoma with relatively large OMCE. Four (7.3%) of 55 consecutive patients with initially operated pituitary macroadenoma (> 10 mm) had OMCE. The combined supra-infrasellar approach was adopted in two cases with relatively large OMCE. RESULTS: The simultaneous combined supra-infrasellar approach was performed with the transcranial microscopic transsylvian anterior temporal approach and the nasal endoscopic approach. The medial main mass was removed through the nasal side. The lateral OMCE was also removed through the nasal side by pushing the tumor in the sellar direction from the transcranial side. The oculomotor nerve was confirmed with electrical nerve stimulation. The main medial mass and the OMCE were mostly removed in both cases. Remnant tumor in the cavernous sinus was treated by gamma knife radiosurgery. Endoscopic transsphenoidal removal was performed in the other two cases with relatively small OMCE. CONCLUSIONS: Pituitary macroadenomas with OMCE are a newly recognized form of progression with important implications for surgical strategy. The combined supra-infrasellar approach performed with the transcranial microscopic transsylvian anterior temporal approach using electrical nerve stimulation and the nasal endoscopic approach may be useful for this type of multi-lobulated pituitary adenoma.

Stereotactic Selective Thalamotomy for Focal Dystonia with Aid of Depth Microrecording.

OBJECTIVE: Long-term effectiveness of selective ventralis intermedius nucleus (VIM)-ventralis oralis nucleus (VO) thalamotomy with depth microrecording for the treatment of focal dystonia was evaluated. The optimal thalamic areas for controlling focal dystonia were studied based on the electrophysiologic and anatomic data. METHODS: Stereotactic selective VIM-VO thalamotomy with depth microrecording was carried out in 8 patients with focal arm and hand dystonia and in 1 patient with cervical dystonia. Electrophysiologic data on the lateral part of thalamic VIM were studied in patients with focal dystonia. A very small and narrow therapeutic lesion was formed in the shape of a square on the sagittal plane and of an I, rotated V, Y, or inverse Y on the axial plane in the VIM-VO, which covered the kinesthetic response area topographically related to focal dystonia. Patients with arm and hand dystonia were followed up for 4.7 ± 3.0 years and 1 patient with cervical dystonia was followed up for 18.2 years. RESULTS: Marked improvement of focal dystonia was shown by functional assessment using the Unified Dystonia Rating Scale. Transient dysarthria was recognized in 1 patient. The sequence of body localization of kinesthetic response in the VIM was clearly shown in patients with focal dystonia. Decreases in the amplitude and amplitude ratio of electromyography on the forearm muscles were markedly significant after VIM thalamotomy, but insignificant after VO thalamotomy immediately after VIM thalamotomy. CONCLUSIONS: Marked reduction of electromyographic tonic discharges of focal dystonia was shown after VIM lesioning. Selective VIM-VO thalamotomy showed good and long-term stable effects for focal dystonia.

Superselective Thalamotomy in the Most Lateral Part of the Ventralis Intermedius Nucleus for Controlling Essential and Parkinsonian Tremor.

OBJECTIVE: The minimum and essential thalamic areas for reducing tremor were investigated in cases treated by superselective thalamotomy in the most lateral part of the ventralis intermedius nucleus (mlp-VIM). METHODS: Stereotactic superselective VIM thalamotomy with depth microrecording was performed in 21 patients with essential tremor (ET) and 15 patients with tremor-dominant Parkinson disease (PD). A very small and narrow (axial plane) therapeutic lesion was formed as a square on the sagittal plane and inverse V on the axial plane in the mlp-VIM, which covered the kinesthetic response area topographically related to tremor. Patients with ET were followed up for 4.7 ± 3.0 years and patients with PD for 7.9 ± 3.9 years. RESULTS: Almost complete tremor control was achieved in all patients immediately after surgery and continued for up to 8 years. A few adverse events were recognized but disappeared within 1 month without 1 patient with thalamic hemorrhage. The medial border of the therapeutic lesion was significantly more lateral in both patients with ET and patients with PD than the calculated standard target point and was in patients with PD than in patients with ET. The mean width was only about 2.4 mm. The individual differences of the adequate location of the therapeutic lesion were significantly greater in the ET than in the PD group. CONCLUSIONS: The important area for reducing tremor was small and narrow and was located in the mlp-VIM, where the proprioceptive ascending signals from the tremor-dominant body part are conducted. Superselective thalamotomy in the mlp-VIM was safe and effective for the long-term in patients with ET and PD.

The outcome of a surgical protocol based on ischemia overprotection in large and giant aneurysms of the anterior cerebral circulation.

Aiming to define the optimal treatment of large and giant aneurysms (LGAs) in the anterior circulation, we present our surgical protocol and patient outcome. A series of 42 patients with intracavernous LGAs (n = 16), paraclinoid (C2) LGAs (n = 17), and peripheral (middle cerebral artery-MCA or anterior cerebral artery-ACA) LGAs (n = 9) were treated after bypass under motor evoked potential (MEP) monitoring. Preoperatively, three categories of ischemic tolerance during internal carotid artery (ICA) occlusion were defined on conventional angiography: optimal, suboptimal, and insufficient collaterals. Accordingly, three types of bypass: low flow (LFB), middle flow (MFB) and high flow (HFB) were applied for the cases with optimal, suboptimal, and insufficient collaterals, respectively. Outcome was evaluated by the Glasgow Outcome Scale (GOS). All patients had excellent GOS score except one, who suffered a major ischemic stroke immediately after surgery for a paraclinoid lesion. Forty-one patients were followed up for 87.1 ± 40.1 months (range 13-144 months). Intracavernous LGAs were all treated by proximal occlusion with bypass surgery. Of paraclinoid LGA patients, 15 patients had direct clipping under suction decompression and other 2 patients with recurrent aneurysms had ICA (C2) proximal clipping with HFB. MEP monitoring guided for temporary clipping time and clip repositioning, observing significant MEP changes for up to 6 min duration. Of 9 peripheral LGAs patients 7 MCA LGAs had reconstructive clipping (n = 4) or trapping (n = 3) with bypass including LFB in 3 cases, MFB in 1 and HFB in 1. Two ACA LGAs had clipping (n = 1) or trapping (n = 1) with A3-A3 bypass. The applied protocol provided excellent results in intracavernous, paraclinoid, and peripheral thrombosed LGAs of the anterior circulation.

Resection extent of the supplementary motor area and post-operative neurological deficits in glioma surgery.

Objective The supplementary motor area (SMA) is important for the prediction of post-operative symptoms after surgical resection of gliomas. We investigated the relationships between clinical factors and the resection range of SMA gliomas, and the post-operative neurological symptoms. Methods We retrospectively studied 18 consecutive surgeries for gliomas involving the SMA proper performed in 13 patients. Seven cases were recurrence of the tumour. Clinical factors and details of specific resection of the SMA proper (resection of posterior part, medial wall) and cingulate motor area (CMA) were examined. Results Eight cases suffered new post-operative neurological deficits. Six of these eight cases had transient deficits. Permanent deficits persisted in two cases with partial weakness or paresis, after rapid improvement of post-operative global weakness or hemiplegia, respectively. The risk of post-operative neurological deficits was not associated with the resection of the posterior part of the SMA proper or the CMA, but was associated with resection of the medial wall of the SMA proper. Surgery for recurrent tumour was associated with post-operative neurological deficits. The medial wall was frequently resected in recurrent cases. Discussion The frequency of post-operative neurological symptoms, including SMA syndrome, may be higher after resection of the medial wall of the SMA proper compared with the resection of only the lateral surface of the SMA proper.

Microrecording and image-guided stereotactic biopsy of deep-seated brain tumors.

OBJECT: Image-guided stereotactic brain tumor biopsy cannot easily obtain samples of small deep-seated tumor or selectively sample the most viable region of malignant tumor. Image-guided stereotactic biopsy in combination with depth microrecording was evaluated to solve such problems. METHODS: Operative records, MRI findings, and pathological specimens were evaluated in 12 patients with small deep-seated brain tumor, in which image-guided stereotactic biopsy was performed with the aid of depth microrecording. The tumors were located in the caudate nucleus (1 patient), thalamus (7 patients), midbrain (2 patients), and cortex (2 patients). Surgery was performed with a frameless stereotactic system in 3 patients and with a frame-based stereotactic system in 9 patients. Microrecording was performed to study the electrical activities along the trajectory in the deep brain structures and the tumor. The correlations were studied between the electrophysiological, MRI, and pathological findings. Thirty-two patients with surface or large brain tumor were also studied, in whom image-guided stereotactic biopsy without microrecording was performed. RESULTS: The diagnostic yield in the group with microrecording was 100% (low-grade glioma 4, high-grade glioma 4, diffuse large B-cell lymphoma 3, and germinoma 1), which was comparable to 93.8% in the group without microrecording. The postoperative complication rate was as low as that of the conventional image-guided method without using microelectrode recording, and the mortality rate was 0%, although the target lesions were small and deep-seated in all cases. Depth microrecording revealed disappearance of neural activity in the tumor regardless of the tumor type. Neural activity began to decrease from 6.3 ± 4.5 mm (mean ± SD) above the point of complete disappearance along the trajectory. Burst discharges were observed in 6 of the 12 cases, from 3 ± 1.4 mm above the point of decrease of neural activity. Injury discharges were often found at 0.5-1 mm along the trajectory between the area of decreased and disappeared neural activity. Close correlations between electrophysiological, MRI, and histological findings could be found in some cases. CONCLUSIONS: Image-guided stereotactic biopsy performed using depth microrecording was safe, it provided accurate positional information in real time, and it could distinguish the tumor from brain structures during surgery. Moreover, this technique has potential for studying the epileptogenicity of the brain tumor.

Pontine venous congestion due to dural arteriovenous fistula of the cavernous sinus: Case report and review of the literature.

BACKGROUND: We report herein a case of cavernous sinus (CS)-dural arteriovenous fistula (DAVF) with brainstem venous congestion that was successfully treated by transarterial embolization, followed by radiotherapy. CASE DESCRIPTION: An 80-year-old woman presented with right eye chemosis and left hemiparesis. T2-weighted magnetic resonance imaging showed hyperintensity of the pons. Diagnostic cerebral angiography demonstrated CS-DAVF draining into the right superior orbital vein and petrosal vein, and fed by bilateral internal and external carotid arteries. Transarterial embolization was performed and followed by radiotherapy, resulting in resolution of the pontine lesion and neurological and ophthalmological symptoms within 5 months. CONCLUSIONS: We also review the literature regarding therapy for CS-DAVF with brainstem venous congestion. Once CS-DAVF with venous congestion of the brainstem has been definitively diagnosed, immediate therapy is warranted. Treatment with transarterial embolization followed by radiation may be an important option for elderly patients when transvenous or transarterial embolization is not an option.

Experimental model of lacunar infarction in the gyrencephalic brain of the miniature pig: neurological assessment and histological, immunohistochemical, and physiological evaluation of dynamic corticospinal tract deformation.

BACKGROUND AND PURPOSE: Lacunar infarction accounts for 25% of ischemic strokes, but the pathological characteristics have not been investigated systematically. A new experimental model of lacunar infarction in the miniature pig was developed to investigate the pathophysiological changes in the corticospinal tract from the acute to chronic phases. METHODS: Thirty-five miniature pigs underwent transcranial surgery for permanent anterior choroidal artery occlusion. Animals recovered for 24 hours (n=7), 2 (n=5), 3 (n=2), 4 (n=2), 6 (n=1), 7 (n=7), 8 (n=2), and 9 days (n=1), 2 weeks (n=2), 4 weeks (n=3), and more than 4 weeks (n=3). Neurology, electrophysiology, histology, and MRI were performed. Seven additional miniature pigs underwent transient anterior choroidal artery occlusion to study muscle motor-evoked potentials and evaluate corticospinal tract function during transient anterior choroidal artery occlusion. RESULTS: The protocol had a 91.4% success rate in induction of internal capsule infarction 286+/-153 mm(3) (mean+/-SD). Motor-evoked potentials revealed the presence of penumbral tissue in the internal capsule after 6 to 15 minutes anterior choroidal artery occlusion. Total neurological deficit scores of 15.0 (95% CI, 13.5 to 16.4) and 3.4 (0.3 to 6.4) were recorded for permanent anterior choroidal artery occlusion and sham groups, respectively (P<0.001, maximum score 25) with motor deficit scores of 3.4 (95% CI, 2.9 to 4.0) and 0.0 (CI, 0.0 to 0.0), respectively (P<0.001, maximum score 9). Histology revealed that the internal capsule lesion expands gradually from acute to chronic phases. CONCLUSIONS: This new model of lacunar infarction induces a reproducible infarct in subcortical white matter with a measurable functional deficit and evidence of penumbral tissue acutely.

Effect of ventralis intermedius thalamotomy on the area in the sensorimotor cortex activated by passive hand movements: fMR imaging study.

Stereotactic ventralis intermedius (Vim) thalamotomy is effective for essential tremor (ET) of the limb, but the effect on the activity of the sensorimotor cortex is still unclear. The functional changes in this cortical area of patients with ET after Vim thalamotomy were investigated using functional magnetic resonance (fMR) imaging. Six patients underwent Vim thalamotomy for medically intractable ET, predominantly in the right hand. 1.5-tesla fMR imaging was performed using the blood oxygenation level-dependent sequence, before and after Vim thalamotomy, during passive movements with right wrist flexion and extension. Before and after images were analyzed using SPM99 software. Activation in the sensorimotor cortex and supplementary motor area evoked by wrist passive movement was observed both before and after surgery. Group analysis of changes in the blood oxygenation level-dependent response revealed a significantly smaller activated area postoperatively. Activation at the fundus of the central sulcus was characteristically decreased. All patients showed marked improvement in tremor after Vim thalamotomy. No patient experienced neurological deficits. fMR imaging showed that activation at the fundus of the central sulcus evoked by passive wrist movement was suppressed after Vim thalamotomy in ET patients, probably due to disruption of the thalamocortical pathway. The fundus of the central sulcus (Brodmann area 3a) is likely to be one of the key relays in the tremor circuit.