Recent studies have reported significant atrophy of the corpus callosum (CC) in Alzheimer's Disease (AD). However, it is currently unknown whether CC atrophy is associated with specific cortical volume changes in AD. Moreover, possible atrophy in extra-callosal commissures has not been examined to date. The purpose of the present study was to quantify atrophy in two cerebral commissures [the CC and the anterior commissure (AC)], to correlate this measure with cognitive status, and to relate commissural size to independent measures of temporal lobe volume in AD patients.

A sample of AD patients and of age- and education-matched normal control subjects (NCs) underwent MRI and a cognitive test battery including the Dementia Rating Scale and Mini Mental State examination. Mid-sagittal regional areas within CC and AC were measured along with superior, middle and inferior temporal lobes volumes.

Alzheimer's Disease patients had significantly smaller callosa than did NCs. The callosal regions most affected in AD included the midbody, isthmus and genu. The isthmus and midbody areas of the CC were positively correlated with cognitive performance and with superior temporal lobe volume in AD patients. The mid-sagittal area of the AC and the superior temporal volumes did not differ between AD patients and NCs.

The study demonstrated that the regional morphology of the CC correlates with current cognitive status and temporal lobe atrophy in AD. As well, the lack of difference for the AC suggests that commissural atrophy in AD is regionally specific.

The goal of this study was to compare the relative contributions from the muscle and the central nervous system to muscle fatigue resistance in aging.

Each subject carried out 90 s of sustained maximal voluntary isometric contraction (MVC) of the thumb using the thenar and forearm thumb muscles. Contractile capacity of the thenar muscles was assessed through tetanic stimulation of the median nerve. Interpolated doublets delivered during an MVC represented the overall voluntary activation level while transcranial cortical stimulation with an electromagnetic stimulator was used to assess motor output upstream from the corticomotoneuronal pathway.

Nine elderly subjects [four females and five males, 70±9 years old (mean±SD)] and 10 younger subjects (five females and five males, 30±6 years old) were tested. After the fatiguing exercise, the elderly group's MVC declined by 29% as opposed to 47% in the younger group (p<0.01). The elderly group's greater fatigue resistance was accounted for by increased fatigue resistance at the muscle level as well as in the central nervous system. At least some of the decline in the central motor drive was upstream from the corticomotoneuronal pathway.

The higher muscle fatigue resistance in the elderly group was attributable to differences in both the peripheral and central nervous systems.

To evaluate the role of stereotactic cyst aspiration in the context of multimodality management of cystic glial and metastatic tumors, we retrospectively reviewed our experience with 38 patients during a 10-year interval.

All 38 patients had one or more computed tomography or magnetic resonance imaging guided stereotactic cyst aspirations. Twenty-seven patients had glial neoplasms and 11 had metastatic brain tumors. Twenty-two patients underwent cyst aspiration as the initial treatment modality while 15 patients had cyst aspiration following previous treatments.

In the immediate postoperative period, 19 of the 27 (70%) patients with gliomas and nine of the 11 (82%) patients with metastatic tumors experienced symptomatic improvement. No procedure-related morbidity was encountered. Twelve patients (31.5%) eventually required a catheter-reservoir system. Thirty-seven percent of patients with cystic glial neoplasms and 18% of patients with metastatic tumors had delayed cytoreductive surgery by craniotomy subsequent to stereotactic cyst aspiration. Reduction in tumor volume following aspiration facilitated Gamma knife radiosurgery in seven patients.

Single stereotactic aspiration is a low risk procedure that provides immediate relief of symptoms in patients with cystic brain tumors. It appears to be valuable together with the use of other therapeutic strategies.

During the pallidotomy procedure, is pre-operative localization with MRI more accurate than CT and does it result in a significant difference in surgical outcome?

Twenty-four Parkinson's Disease patients received a unilateral pallidotomy for their motor symptoms. Dyskinesia was scored pre- and six weeks postoperatively. All patients had a pre-operative CT scan and MRI to calculate the target co-ordinates. Patients were then randomly selected to proceed with either the CT or MRI coordinates. The final position for the lesion was determined with intraoperative macrostimulation and impedance measurements. The percentage improvement of dyskinesia was noted for each patient and the two groups compared by the Mann-Whitney test. The distance from the final target to the MRI and CT pre-operative co-ordinates were calculated for each patient. The mean distance for each modality was then compared by Student's t-test. The number of electrode repositionings was also recorded for each patient and the two groups compared by the nonparametric Mann-Whitney test.

Although the MRI co-ordinates were significantly (p<0.023) closer to the final target, this did not translate into a significant reduction in electrode repositionings. There was no significant difference in the improvement in dyskinesia between the two groups.

The pre-operative MRI co-ordinates were significantly (p=0.023) closer to the final target than those from the CT. The potential advantages and disadvantages of both imaging modalities are reviewed. There was no significant difference in surgical outcome using either MRI or CT for pre-operative localization in pallidotomy.

We investigated the in vitro effects of low- and high-dose methylprednisolone (MP) on the cytokine-induced expression of HLA-DR, ICAM-1 and VCAM-1 on human brain microvessel endothelial cells (HBMECs).

Brain endothelium was obtained from microvessels included in the apparently normal white matter of surgical specimens of nine patients. Cells were stained with monoclonal antibodies anti-HLA-DR, anti-ICAM-1 and anti-VCAM-1 and analysed by flow cytometry as fluorescence histograms. The mean fluorescence intensity (MFI) of HBMECs treated with different stimuli was calculated.

3-IFN-induced HLA-DR was down-regulated in a dose-dependent manner by MP. High-dose MP reduced the TNF-3-induced ICAM-1 and VCAM-1 expression.

The down-regulation of adhesion molecules on cerebral endothelial cells could decrease mononuclear cell transmigration through the blood brain barrier and consequently the perivascular infiltrates. The results add support to the rationale for high-dose MP treatment in multiple sclerosis relapses.

“Blister-like” aneurysms of the supraclinoid internal carotid artery have recently been recognized as having unique pathological and clinical features. Little is known regarding their optimal treatment modality.

We report a case of a “blister-like” aneurysm of the internal carotid artery treated with Guglielmi detachable coil (GDC) embolization. Case Report: A 55-year-old man presented with a Hunt & Hess grade II subarachnoid hemorrhage. Computed tomography revealed diffuse subarachnoid blood. Cerebral angiography demonstrated a broad-based bulge on the medial wall of the right distal internal carotid artery. The patient was taken to the operating room and underwent a right pterional craniotomy and wrapping of this unclippable aneurysm. On postoperative day 11, he developed signs of vasospasm, and repeat angiography showed remarkable growth of the aneurysm. The aneurysm was believed to be amenable to endovascular therapy and was treated by GDC embolization. The patient recovered well and remained neurologically intact on follow-up examinations. Repeat cerebral angiography was performed three and nine months following his initial presentation and revealed a significant aneurysm neck remnant. This neck remnant was treated by repeat GDC embolization 13 months following his subarachnoid hemorrhage.

“Blister-like” aneurysms of the internal carotid artery are important to recognize and are difficult to manage using traditional surgical approaches. Early repeated cerebral angiography is indicated and, where appropriate, endovascular therapy should be considered in the management of these patients.

The occurrence of a unilateral sensory loss in the second trigeminal distribution and the inability to tear following an ipsilateral temporal lobectomy has not been noted despite a number of reports of cranial nerve compromise under similar situations.

A 48-year-old woman experienced complex partial seizures over three years attributable to the presence of cavernous malformations of the right temporal lobe.

An anterior temporal extrahippocampal resection was performed. The surgery was marked by the need for electrocoagulation of the dural base of the temporal lobe where numerous bleeding points were encountered. Postoperatively, the patient experienced an ipsilateral maxillary division sensory loss, absence of tearing, and diminished nasal congestion for an eight-month period until resolution.

Injury of the fibers of the maxillary division of the trigeminal nerve and the adjacent greater superficial petrosal nerve appears to be the cause. No prior account of such an occurrence has been published.