Dynamic and three-dimensional transcranial ultrasonography of an arachnoid cyst in the cerebral convexity. Technical note.

Structural imaging of the brain, such as cerebral computerized tomography (CT) and magnetic resonance (MR) imaging, is state-of-the-art. Dynamic transcranial (dTC) ultrasonography and three-dimensional (3D) transcranial color-coded duplex (TCC) ultrasonography are complementary, noninvasive procedures with the capacity for real-time imaging, which may aid in the temporary management of space-occupying lesions. A 16-year-old woman presented with recurrent tension-type headaches. A space-occupying arachnoid cyst in the cerebral convexity was demonstrated on MR images. The patient underwent an examination for raised intracranial pressure. which was performed using a standard color-coded duplex ultrasonography system attached to a personal computer-based system for 3D data acquisition. Transcranial ultrasonography was used to identify the outer arachnoid membrane of the cyst, which undulated freely in response to rotation of the patient's head (headshake maneuver). Three-dimensional data sets were acquired and, using a multiplanar reformatting reconstruction algorithm, the authors obtained high-resolution images that corresponded to the initial MR image and a follow-up cranial CT scan. No detectable differences were observed on dTC or 3D TC ultrasonograms obtained at follow-up examinations performed 9 and 28 months later. Three-dimensional TCC and dTC ultrasonography may complement conventional diagnostic procedures such as MR and CT imaging. This report represents evidence of the high resolution and good reproducibility of 3D TC methods. Ultrasonography is a mobile and inexpensive tool and may be used to improve management and therapeutic strategies for patients with space-occupying brain lesions in selected cases.

Deep hypothermia and circulatory arrest for surgery of complex intracranial aneurysms.

OBJECTIVE: Some intracranial aneurysms may not be operable by conventional neurosurgery due to their location or morphology. Cardiopulmonary bypass (CPB) and deep hypothermic circulatory arrest renders surgery of these complex aneurysms possible. Brain temperatures can be measured directly in this setting. METHODS: Eight patients with complex intracranial aneurysms were operated on with the aid of CPB. Femoro-femoral bypass with heparin-coated circuit components was used in all cases. Venous drainage was augmented by a centrifugal pump in six patients and by a newly developed vacuum technique in two patients. Temperatures were monitored by probes in brain, tympanum, nasopharynx, bladder, rectum, arterial and venous blood. These measurements were recorded on-line together with those of cerebral oxygen saturation, AP, CVP and PAP. Blood gas analyses and an EEG were also performed continuously. RESULTS: Outcome was excellent in seven patients, in one patient moderate neurological disability occurred. Mean time on cardiopulmonary bypass was 160 (117-215) min, for cooling to a brain temperature of 18 degrees C 33 (20-47) min, and for total circulatory arrest 27 (15-45) min. Additionally, terminal brain arteries were clamped for up to 68 min in four patients. No cardiac complications were observed. Actual brain temperatures were best reflected by the tympanum probes (max. deviation 2 degrees C), whereas temperatures measured in bladder or rectum exhibited deviations of up to 10 degrees C. EEG activities were arrested between brain temperatures of 19 and 26 degrees C. CONCLUSIONS: Complex intracranial aneurysms can be treated successfully using deep hypothermic circulatory arrest. Extensive monitoring adds to the speed and safety of the procedure. The resulting comparative measurements of temperatures at different body sites including brain, EEG, and other variables may be of general relevance for operations employing deep hypothermia and circulatory arrest.

Sonographic parenchymal and brain perfusion imaging: preliminary results in four patients following decompressive surgery for malignant middle cerebral artery infarct.

To investigate new methods of diagnostic transcranial sonography for brain parenchymal, vascular and perfusion imaging, we performed 3-D native tissue harmonic transcranial sonography (3D-nthTCS), 3-D transcranial color-coded duplex sonography (3D-TCCS), and "loss-of-correlation" imaging (LOC-TCCS) in four patients following early hemicraniectomy due to space-occupying "malignant" middle cerebral artery infarction (MMCAI). Three-dimensional datasets, utilizing 3D-nthTCS and 3D-TCCS, were created and up to 10 axial 2-D B-mode image planes, similar to CCT, reconstructed in each patient. Three-dimensional reconstructions of the circle of Willis documented one persistent carotid-T occlusion and three recanalizations of the MCA. LOC-TCCS, based on stimulated acoustic emission from an ultrasound (US) contrast agent, demonstrated a perfusion deficit in 2 of 3 patients, with regard to their infarcts. Concluding, 3D-nthTCS, 3D-TCCS and LOC-TCCS are promising tools for bedside monitoring, early prognosis and treatment evaluation for MMCAI in the postoperative period. Further studies should be performed to standardize these new methods and evaluate their applications through the intact calvarina.

Cognitive decline as an important sign for an operable cause of dementia: chronic subdural haematoma.

BACKGROUND: Cognitive decline, slow psychomotor regression and confusion, especially in the elderly, often result in medical consultation. Frequently, these rather unspecific symptoms are interpreted as signs of beginning dementia. When mental regression is joined by tremor or motor deficits, neurodegenerative disease is commonly considered and the need for neuroimaging is underestimated. Chronic subdural haematoma (CSH) is known to be the most frequent type of intracranial bleeding, appearing mostly in the elderly after minor trauma with unspecific symptoms. The aim of this retrospective study was the identification of the leading clinical symptoms in patients with the diagnosis CSH who had been treated surgically in our Neurosurgical Department. PATIENTS AND METHOD: 356 patients with symptomatic CSH (225 male, 131 female; mean age 68.3 years), who were admitted to our Neurosurgical Department between 1992 and 2003, were included in the study. We reviewed the charts documenting preoperative clinical status, radiological signs, history of trauma, operative complications, postoperative clinical status, days of hospitalisation as well as gender and age. RESULTS: The primary surgical procedure performed in 343 patients (96.4%) was burr-hole trepanation. The leading preoperative symptoms were mnestic deficits (cognitive decline, confusion) in 192 patients (55.8%), followed by headache in 150 patients (45.5%) and motor deficit in 144 patients (41.1%). Furthermore, we found a statistically significant correlation (p<0.005) between the thickness of the left-sided haematoma and the symptoms aphasia and psychosyndrome. CONCLUSION: The leading clinical symptoms identified in our cohort were mnestic deficits, headache and motor deficit, signs that mostly appear at the beginning of demential diseases. Thus, CSH should be taken into account as an important differential diagnosis for demential and neurodegenerative diseases and neuroimaging should be demanded. Once a CSH is detected this way, the patient should be transferred to a neurosurgical department where an easy standard procedure may potentially lead to early recovery.

Comparison of the Claassen and Fisher CT classification scale to predict ischemia after aneurysmatic SAH?

BACKGROUND: Delayed cerebral ischemia (DCI) is an important cause of morbidity and mortality after aneurysmatic subarachnoid hemorrhage (SAH). The severity of SAH, reflected by the amount of blood in the initial CCT, is a well-established predictor of DCI and infarction. The Fisher CT scale is widely used to predict DCI, but recent studies criticised the scale due to the fact that this scale does not differentiate between intracerebral blood clots and intraventricular hemorrhage. Thus Claasen et al. recently proposed a new grading scale to predict DCI. The aim of this study was to compare clinical scales with the CT findings and to verify this newly developed scale in a different population in order to predict DCI.[nl] PATIENTS AND METHODS: We selected from our databank of patients suffering from aneurysmatic SAH 292 cases who had been treated between 1995 and 2000. The data acquisition included clinical data, radiological diagnostic data, the postoperative surgical course as well as a follow-up according to the Glasgow outcome scale.[nl] RESULTS: 83 out of 292 patients (28.5 %) developed ischemic lesions on the CT scans reflecting DCI. The severity of SAH according to the Hunt and Hess grading, the Fisher CT scale and the Claassen CT scale correlated statistically significant to DCI. All three scales showed an increasing odds ratio, but the most consistent increase was demonstrated by the Fisher scale.[nl] CONCLUSIONS: The newly proposed Claassen CT scale provides no additional information and seems not to be superior compared to the well-established Fisher scale to predict DCI.

Cerebral CT angiography in the diagnosis of acute subarachnoid hemorrhage.

PURPOSE: To evaluate the usefulness of CT angiography (CTA) in the detection of intracranial aneurysms in patients with acute subarachnoid hemorrhage (SAH). MATERIAL AND METHODS: In 53 patients with nontraumatic SAH a helical contrast-enhanced CTA was performed. CTA data were reconstructed with maximum intensity projection (MIP). Each patient underwent selective arteriography of the cerebral vessels (as the gold standard). CTA (axial images and MIP reconstructions) and arteriography were evaluated separately and their diagnostic information was compared. RESULTS: In 14 of the 53 patients neither CTA nor angiography showed a vascular malformation. In the remaining 39 patients, angiography demonstrated a total of 51 aneurysms ranging in size from 3 mm to 16 mm. CTA missed one of these aneurysms, which was located at the internal carotid artery. 3-D CT reconstruction was slightly superior to arteriography in the demonstration of the neck, shape and direction of the aneurysms. Partial thrombosis of 3 aneurysms was demonstrated only by CTA. CONCLUSION: Although CTA cannot replace cerebral arteriography in the diagnostic work-up of acute SAH, it proved to be helpful in demonstrating the topographic anatomy of cerebral aneurysms and surrounding structures.

Short-term prognostic factors in lumbar disc surgery: the low back prognostic score is of predictive value.

In order to determine prognostic factors of lumbar disc surgery, we examined 107 patients who were conventionally operated on in a prospective, consecutive study. We analysed general data, the case history, the neurological examination at admission and all data from imaging examinations and therapy. In addition, all patients received a questionnaire based on the Low Back Outcome Score [9, 10]. The patients were re-examined after 2-8 months (103 days mean). According to their ratings on a pain grading scale, the patients were divided into a group with favorable and another with unfavorable results. These groups were analysed in relation to the patients' initial condition. At follow up, 88% of the patients had either completely recovered or their complaints had been relieved. According to the Low Back Outcome Score (LBOS), 64.5% went well. Used to evaluate the initial condition of the patients on admission the LBOS was able to predict favorable outcome in 68% and unfavorable outcome in 50%. To improve the prognostic value, we combined significant questions of the LBOS with the pain grading scale and significant prognostic factors to form a new prognostic score (Low Back Prognostic Score). With this new score we were able to predict a favorable outcome in 84% of our patients, and an unfavorable outcome in 71%. The Low Back Prognostic score seems to provide a sensitive method for predicting a favorable or unfavorable outcome for patients scheduled to undergo lumbar disc surgery.

Augmentation of the rocuronium-induced neuromuscular block by the acutely administered phenytoin.

BACKGROUND: The effects of an acute administration of phenytoin on the magnitude of the rocuronium-induced neuromuscular block were evaluated. METHODS: Twenty patients (classified as American Society of Anesthesiologists physical status I or II) scheduled for craniotomy were studied: 15 received phenytoin during operation (10 mg/kg), and the others served as controls. Anesthesia was induced with thiopental and fentanyl and maintained with nitrous oxide (65%) in oxygen and end-tidal isoflurane (1%). The ulnar nerve was stimulated supramaximally and the evoked electromyography was recorded using a neuromuscular transmission monitor. Continuous infusion of rocuronium maintained the neuromuscular block with first twitch (T1) between 10 and 15% for 45 min before the start of an infusion of either phenytoin or NaCl 0.9%. Twitch recordings continued for 60 min thereafter. Arterial blood samples were collected at the predefined time points (four measurements before and four after the start of the infusion) to determine the concentrations of phenytoin and rocuronium and the percentage of rocuronium bound to plasma proteins. RESULTS: The first twitch produced by an infusion of rocuronium remained constant during the 15 min before and the 60 min after the start of the saline infusion. After the phenytoin infusion, the twitch decreased progressively, but the plasma concentrations and the protein-bound fraction of rocuronium did not change. CONCLUSION: Phenytoin acutely augments the neuromuscular block produced by rocuronium without altering its plasma concentration or its binding to plasma proteins.