Morphometric studies of the ligamentum flavum: a correlative microanatomical and MRI study of the lumbar spine.

BACKGROUND: Foraminal degenerative lumbar stenosis is traditionally considered a result of bony narrowing due to osteophytic appositions on the superior articular process. Clinical experience reveals that significant additional compression of the neural structures is due to degenerative hypertrophy of the adjacent ligamentum flavum. Therefore, microanatomical and neuroradiological investigations were performed to determine the microtopography of this ligament, especially with respect to its lateral extension. METHODS: Lumbar spine specimens of eight mid-aged human cadavers (mean age 34.5 years) were collected, and MRI studies with T1-weighted images were performed. The specially embedded specimens were sectioned horizontally at the level of the spinal ganglion (slice thickness: 2 mm). Anatomical morphometric data were correlated with identical measurements based on neuroradiological imaging and were analyzed statistically. RESULTS: The distance between midline and extraforaminal extension of the ligamentum flavum showed a mean value of 17 mm. The distance increased to 19 mm when the lateral insertion was correlated to the origin of the ligamentum flavum at the anterior margin of the lamina. The farthest lateral segment of the ligamentum flavum was determined in each case; it covered the synovial cavity of the lumbar facet joint in the direction of the extraforaminal segment of the intervertebral canal. CONCLUSIONS: Measurements from mid-aged cadavers show the extent of the ligamentum flavum including its intra- and extraforaminal parts. Due to this anatomical situation a hypertrophic ligamentum flavum may contribute significantly to nerve root compression at the level of the lateral spinal recess. This has to be kept in mind during surgical decompression, which might be incomplete unless these hypertrophied parts are completely removed.

Management of haemorrhagic type moyamoya disease with intraventricular haemorrhage during pregnancy.

Moyamoya ("hazy puff-of-smoke") disease represents a rare condition with progressive narrowing and occlusion of basal cranial vessels with secondary specific neoangiogenesis; we report on a 25-year-old primigravida with known moyamoya disease who suffered from acute bilateral intraventricular haemorrhage at 24 weeks gestation. She underwent bilateral external ventricular drainage and intraventricular recombinant tissue plasminogen activator (r-TPA) lysis was performed. At 34 weeks' gestation, a healthy girl was delivered via Caesarean section. Encephalomyosynangiosis (EMS) and extra-intracranial (EC/IC) bypass surgery were performed six and eight months after delivery, respectively. The patient recovered almost completely and showed only mild residual deficits. Prompt diagnosis and immediate interdisciplinary treatment might have been the key for optimal maternal and neonatal outcome in our patient.

[Comparison of the Aachen Aphasia Test, clinical study and Aachen Aphasia Beside Test in brain tumor patients]. / Vergleich von Aachener Aphasie-Test, klinischer Untersuchung und Aachener Aphasie-Bedside-Test bei Hirntumorpatienten.

In the clinical routine examination of patients with brain tumors, aphasic symptoms are often not recognized. In order to document the incidence of such symptoms, three diagnostic methods of testing for aphasia were compared: the Aachen aphasia test (AAT), which is the German standard aphasia test, clinical examination, and the Aachen aphasia bedside test (AABT), which was designed to test patients in the acute phases of illness. In the AAT, 50% of patients with left-sided tumors and 36% of those with right-sided tumors showed aphasic disturbances. The AAT results were defined as the gold standard. Clinical examination showed only low sensitivity; less than half of the aphasic patients were diagnosed as such. The AABT also detected only about half of the patients with aphasic disturbances. The low sensitivity is caused mainly by the results of the patients with right-hemisphere tumors, in which the mental set of the examiner during clinical examination (aphasic symptoms are not expected in patients with right-hemisphere lesions) and the pattern of disturbances in the AABT (deficits may be less severe and different in nature) may prevent detection of aphasic symptoms. Both clinical examination and AABT are thus not suitable for aphasia diagnostics in brain tumor patients. As the AAT is very time-consuming in everyday clinical routine, however, the development of an aphasia screening test seems desirable.

Ictal ECD-SPECT differentiates between temporal and extratemporal epilepsy: confirmation by excellent postoperative seizure control.

We investigated whether ictal single photon emission computed tomography (SPECT) with 99Tcm-ethyl cysteinate dimer (ECD) could differentiate between temporal (TE) and extratemporal epilepsy (ETE) in 30 consecutive patients (n = 21 for TE, n = 9 for ETE), all of whom had excellent postoperative seizure control (class I according to Engel's classification). Ictal SPECT showed isolated temporal hyperperfusion in 90% (19 out of 21) of the TE patients and normal perfusion in two patients. All the ETE patients had ictal SPECT findings consistent with extratemporal seizure onset. The sensitivity of ictal ECD-SPECT for correct localization of the seizure onset zone was 80% in all patients, 86% in TE patients and 66% in ETE patients. Although ictal ECD-SPECT has a lower sensitivity in ETE than in TE, it can be used to clearly distinguish between TE and ETE. It provides non-invasive imaging information for use in further diagnostic and treatment strategies in patients with drug-resistant focal epilepsy.

Tonic seizures: their significance for lateralization and frequency in different focal epileptic syndromes.

PURPOSE: To determine whether the clinical features of tonic seizures (TSZ) are useful for lateralization of epileptic syndromes and the differential diagnosis of focal epileptic syndromes. METHODS: From a group of 481 patients, 123 patients with TSZ (44 females; mean age, 22.9 years; mean age at onset, 7 years; mean duration of epilepsy, 16 years) were selected. A total of 1595 epileptic seizures, documented during videoelectroencephalographic monitoring, were analyzed. Patients who had had surgery for epilepsy previously were excluded. Seizures were classified using a semiological seizure classification. Epilepsy syndromes were classified using all test data (electroencephalography, magnetic resonance imaging, computed tomography, positron emission tomography, and single-photon emission tomography). Data were compared using chi2 analysis or the Fisher exact test. RESULTS: More patients with TSZ had extratemporal than temporal lobe epilepsies (79% vs. 1.7%; p < 0.0001) among those with an epilepsy localized to one lobe (n = 306). In the 123 patients, TSZ were part of 170 different seizure evolutions. Seizure evolutions began with TSZ as the first seizure type more often in patients with frontal lobe epilepsy (FLE) compared with patients with parieto-occipital lobe epilepsy (POLE) (40% in POLE vs. 67% in FLE; p < 0.05). In contrast, TSZ in POLE were more likely to be preceded by auras (50% in POLE vs. 26% in FLE; p < 0.05). TSZ were bilateral in 129 (76%) and unilateral in 41 (24%) seizure evolutions. Unilateral TSZ correctly lateralized the epilepsy syndrome to the contralateral hemisphere. CONCLUSION: Analysis of seizure semiology and evolution in patients with TSZ is helpful for differentiating between focal epilepsies of temporal, frontal, and parieto-occipital origin. Unilateral TSZ provide useful information for the lateralization of the epileptic syndrome.

Ictal SPECT hyperperfusion reflects the activation of the symptomatogenic cortex in spontaneous and electrically-induced non-habitual focal epileptic seizures: correlation with subdural EEG recordings.

We report a patient with left temporal lobe epilepsy and a left parietal angioma, in whom ictal SPECT showed hyperperfusion in a spontaneous and an electrically-induced, non-habitual focal seizure. A SPECT investigation during an habitual seizure originating in the left temporal lobe showed a left temporal hyperperfusion. Electrical stimulation of the parietal cortex adjacent to the location of a previously resected angioma using subdural electrodes resulted in a non-habitual seizure beginning with a unilateral somatosensory aura. Ictal SPECT of this seizure demonstrated contralateral central hyperperfusion. We conclude from our findings that ictal SPECT hyperperfusion reflects the activation of symptomatogenic cortex, which can be induced by both epileptic discharge and electrical stimulation.

Usefulness of 3-D reconstructed images of the human cerebral cortex for localization of subdural electrodes in epilepsy surgery.

Three-dimensional (3-D) images of 14 patients, in whom subdural electrodes were implanted for epilepsy surgery evaluation, were produced by fusing computerized tomography (CT) scans and magnetic resonance images (MRI) to determine the exact location of the electrodes. In 25% (198 of 806) of the subdural electrodes an exact location for resection strategy was not evident from the X-rays. The location of these electrodes ('doubtful location', DL) was compared to the 3-D images. Intraoperative inspection served as the gold standard. Concordance score was defined as good for 75-100% concordance, moderate for 50-75%, and poor for less than 50% concordance of the DL electrodes to the intraoperatively determined location. A comparative analysis of the 3-D images and X-ray films showed a highly significant difference (P < 0.0002) in favor of 3-D images. The concordance score for the DL electrodes in the 3-D images was good in 93% of the patients and moderate in 7%. In contrast, the concordance score was good in only 7% of the patients for the two-dimensional (2-D) skull films, moderate in 57%, and poor in 36%. Interobserver reliability was better for 3-D images (93%) than for the 2-D X-rays (43%). These findings suggest that 3-D images aid preoperative planning for resective epilepsy surgery.

Influence of cranioplasty on postural blood flow regulation, cerebrovascular reserve capacity, and cerebral glucose metabolism.

OBJECT: The indications for cranioplasty after decompressive craniectomy are cosmetic repair and, mainly, restoration of cerebral protection. Although neurological improvement after cranioplasty is repeatedly noted, the reasons for this remain unclear. Few observations concerning the impact of cerebrospinal fluid hydrodynamic and/or atmospheric pressure have been published during the last decades. Relevant data concerning the cerebrovascular reserve (CVR) capacity and cerebral glucose metabolism before and after cranioplasty have been lacking until now. To gain further insight, this study was undertaken to investigate the impact of cranioplasty on indices of cerebral blood flow regulation and metabolism. METHODS: Thirteen patients in whom extensive craniectomies had been performed underwent a meticulous study of blood flow velocities in the middle cerebral artery (MCA) and extracranial internal carotid artery (ICA), as assessed by transcranial Doppler ultrasonography during postural maneuvers (supine and sitting positions) and during stimulation with 1 g of acetazolamide for the interpretation of CVR capacity. Twelve patients underwent 18-fluorodeoxyglucose positron emission tomography. These measurements were obtained before and 7 days after cranioplasty. Cranioplasty improved preoperative differences in MCA blood flow velocities when comparing those in the injured with those in the uninjured hemisphere. Similarly, cranioplasty resolved decreases in extracranial ICA blood flow in the injured hemisphere that were induced by postural changes, which was a constant finding prior to this procedure. More strikingly, however, the CVR capacity, which was severely impaired in both hemispheres, increased significantly after the procedure. Metabolic deficits, which were observed in the injured hemisphere, were found to improve after reimplantation of the skull bone flap. CONCLUSIONS: Cranioplasty appears to affect postural blood flow regulation, CVR capacity, and cerebral glucose metabolism markedly. Thus, early cranioplasty is warranted to facilitate rehabilitation in patients after decompressive craniectomy.

Reduction of benzodiazepine receptor binding is related to the seizure onset zone in extratemporal focal cortical dysplasia.

PURPOSE: Comparison of regional reduction of GABA receptor binding and seizure onset zone in patients with extratemporal epilepsy due to focal cortical dysplasia. METHODS: Two patients with frontal lobe epilepsy who remained seizure free after partial frontal lobe resection were investigated with magnetic resonance imaging, positron emission tomography (PET) with 18F-fluoro-deoxy-glucose (FDG) and 11C-flumazenil, subdural EEG-video recordings, and postoperative benzodiazepine (BDZ)-receptor autoradiography. RESULTS: The area of reduced BDZ-receptor binding as documented by preoperative flumazenil-PET and postoperative BDZ-receptor autoradiography corresponded to the seizure onset zone and was smaller than the interictal hypometabolism documented by FDG-PET. CONCLUSION: Flumazenil-PET is a useful tool for localization of the epileptogenic zone in patients with extratemporal epilepsy caused by focal cortical dysplasia. Neuronal distribution of BDZ-receptor density confirms in vivo flumazenil-PET findings. The regional reduction of BDZ-receptor binding in focal cortical dysplasia seems to be confined to the seizure onset zone and not to the extent of dysplastic cortex.

Transcallosal interforniceal-transforaminal approach for removing lesions occupying the third ventricular space: clinical and neuropsychological results.

OBJECTIVE: The present study was undertaken to describe the clinical and prospective neuropsychological results for our group of 30 patients who were treated using a transcallosal interforniceal-transforaminal microsurgical approach. METHODS: The transcallosal interforniceal and transcallosal-transforaminal approaches were used to treat 30 patients with space-occupying lesions located in the anterior part of the third ventricle. We used a modified anterior transcallosal microsurgical approach, as described recently. The patients underwent extensive, pre- and postoperative, prospective neuropsychological testing, using a specially designed test battery. RESULTS: Twenty-three of 30 patients (77%) experienced excellent clinical outcomes (Glasgow Outcome Scale Grade V). The surgical procedures described in this report did not themselves impair attentional function. In both the early and late postoperative neuropsychological testing sessions, deficits in verbal memory were only rarely observed and were not noted to be correlated with the surgical procedures. The most relevant neuropsychological results for individual patients are reported in detail. CONCLUSION: The approach described here can be successfully used for the resection of various space-occupying lesions in the anterior part of the third ventricle. The anatomic landmarks we recently defined and described (for example, the midline vessel on the trunk of the corpus callosum, to direct the callosotomy) guide the surgical path. Furthermore, we recommend the use of neuropsychological test batteries for both scientific and rehabilitative purposes.

Foreign-body reaction to silastic burr-hole covers with seroma formation: case report and review of the literature.

Because silastic material is one of the most commonly used biomaterials in modern medicine, the biocompatibility of these implants is still a source of long standing controversy. Though several studies have established silastic material as biologically inert, numerous authors have repeatedly described characteristic pathological tissue responses to silicone and its elastomeres. We report a case of foreign-body reaction to silastic burr-hole cover with successive formation of a seroma following resection of an olfactory groove meningioma. Within 30 days postoperatively, the patient developed a marked bulge in the glabbelar region. Histopathological examination revealed a seroma-like lesion obviously caused by a chronic inflammatory allergic reaction to the silastic burr-hole cover. Although the silicone-induced tissue damage clinically shows a wide variability and a conclusive model of pathogenesis is presently not available, the histopathological findings in some patients, in the form of granulomatous lesions and inflammatory cell response, might partly be due to an immunological reaction. Such a reaction has been previously described both clinically and experimentally, as detected in our patient. In addition, a review of the literature is given.

Histologically repeatedly confirmed gliosarcoma with long survival: review of the literature and report of a case.

OBJECTIVE AND IMPORTANCE: A rare case of gliosarcoma in a 61-year-old woman is presented with a stable situation over 22 years with an excellent quality of life. CLINICAL PRESENTATION: The patient was initially symptomatic and was operated on in 1975 for a deep-seated left parietal gliosarcoma. During the following 20 years, she was clinically asymptomatic until she complained of increasing headache in 1995. Neuroradiological imaging showed a sharply demarcated lesion on MRI at the former operative site, which was operated on again. Four months later, the residual tumour did grow again. INTERVENTION: As radiation therapy could not stop tumour progression and the neurological status worsened, the patient was operated on again for a massive tumour mass in the left parieto-occipital region, filling out nearly all of the previous resection cavity. Despite radio-immunotherapy, the patient finally died 22 years after the first discovery of the tumour. CONCLUSION: The present case shows that, in rare instances, gliosarcomas may show prolonged survival, although the underlying pathogenetic mechanisms for this clinical behaviour are not understood.

Closure of recurrent frontal skull base defects with vascularized flaps -- a technical case report.

Techniques for vascularized reconstruction of the anterior cranial fossa floor defects causing recurrent cerebrospinal fluid fistula are discussed in this report. The closure employs the use of local random- or axial-pattern vascularized flaps in simple cases. In complicated cases (for instance, status after repeated exploration) the tissue of the cranial base is severely compromised and shows low potential for healing. Non-vascularized grafts only add avital scars to the already present ones leading to recurrent fistulas. Free vascularized flaps show more mechanical strength and less scar contraction, resistance to infections and survive better in a compromised surrounding, thus leading to long term sealing in such cases. The technical issues of vascularized closure of defects of the frontal skull base are discussed in this report.

The influence of cranioplasty on postural blood flow regulation, cerebrovascular reserve capacity, and cerebral glucose metabolism.

The indications for cranioplasty after decompressive craniectomy are cosmetic repair and, mainly, restoration of cerebral protection. Although neurological improvement after cranioplasty is repeatedly noted, the reasons for this still remain unclear. Few observations concerning the impact of CSF hydrodynamic and/or atmospheric pressure were published during the last decades. Relevant data concerning the cerebrovascular reserve capacity and cerebral glucose metabolism before and after cranioplasty have been lacking until now. To gain further insight, the present study was undertaken to investigate the impact of cranioplasty on indices of cerebral blood flow regulation and metabolism. Thirteen patients in whom extensive craniectomies had been performed underwent a meticulous study of blood flow velocities in the middle cerebral artery (MCA) and extracranial internal carotid artery (ICA), as assessed by transcranial Doppler (TCD) ultrasonography during postural maneuvers (supine and sitting positions) and during stimulation with 1 g of acetazolamide for the interpretation of cerebrovascular reserve (CVR) capacity. Twelve patients underwent 18-fluorodesoxyglucose positron emission tomography. These measurements were made before and 7 days after cranioplasty. Cranioplasty improved preoperative differences in MCA blood flow velocities when comparing the injured with the noninjured hemisphere. Similarly, cranioplasty resolved decreases in extracranial ICA blood flow in the injured hemisphere that were induced by postural changes, which was a constant finding prior to this procedure. More strikingly, however, the CVR capacity, which was severely impaired in both hemispheres, significantly increased after the procedure. Metabolic deficits, which were observed in the injured as compared with the noninjured hemisphere, were found to improve after reimplantation of the skull bone flap. Cranioplasty appears to affect postural blood flow regulation, CVR capacity, and cerebral glucose metabolism markedly. Thus, early cranioplasty is warranted to facilitate rehabilitation in patients after decompressive craniectomy.

Transcallosal approach to the third ventricle: normative morphometric data based on magnetic resonance imaging scans, with special reference to the fornix and forniceal insertion.

OBJECTIVE: The ability to visualize median-sagittal brain structures by magnetic resonance imaging (MRI) improves the planning for surgical removal of lesions located in and around the third ventricle. The transcallosal approach is the most appropriate path to the anterior part of the third ventricle. The present study was undertaken to obtain normative morphometric data, derived from sagittal MRI scans, which are necessary for operation planning that takes into account the surgical microanatomy and landmarks encountered during this approach. METHODS: The morphometric evaluation was performed on 72 median-sagittal MRI scans. The surface landmarks for the corridor were the two points, P5 and P7, located 5 and 7 cm anterior to the central sulcus, respectively. With these two points on the cortical surface as references, a variety of measurements were made to provide quantitative information about distances between brain structures encountered during the surgical approach. In addition, various parameters were determined to characterize the different shapes of the fornix and the different types of forniceal insertion. RESULTS: The following measurements (means) were obtained: 1) the distance between P5/P7 and the cingulate sulcus was 25.76 mm (range, 17.113-42.73 mm) with reference to P5, and 25.41 mm (range, 12.91-36.29 mm) with reference to P7; 2) the distance between the cingulate sulcus and the corpus callosum was 12.91 mm (range, 7.19-22.60 mm) with reference to P5, and 12.92 mm (range, 6.75-23.37 mm) with reference to P7; 3) the height of the corpus callosum was 6.22 mm (range, 3.07-9.00 mm) with reference to P5, and 6.92 mm (range, 3.50-13.57 mm) with reference to P7; 4) the distance between the anterior commissure and the foramen of Monro was 6.78 mm (range, 1.86-14.57 mm), independent of P5 and P7; 5) the distance between the lower margin of the corpus callosum and the upper insertion point of the fornix was 12.44 mm (range, 2.71-26.13 mm) with reference to P5, and 13.34 mm (range, 3.74-27.58 mm) with reference to P7; 6) the distance between the lower margin of the corpus callosum and the lower insertion point of the fornix was 18.08 mm (range, 9.47-29.71 mm) with reference to P5, and 18.58 mm (range, 10.48-30.40 mm) with reference to P7; and 7) the distance between the lower margin of the corpus callosum and the anterior commissure was 23.46 mm (range, 11.98-32.70 mm) with reference to P5, and 22.89 mm (range, 11.05-33.04 mm) with reference to P7. Four different insertion types between the fornix and the corpus callosum were noted and classified. CONCLUSION: Morphometric data concerning the surrounding structures of the third ventricle have received very little attention in the literature. This morphometric study permitted definition of the surgical corridor to the third ventricle by preserving important anatomic structures such as the motor strip, genu of the corpus callosum, forniceal commissure (hippocampal commissure), anterior commissure, and forniceal columns. The detailed morphometric data obtained on median-sagittal MRI scans of the brain structures involved in the transcallosal interforniceal and/or transcallosal transforaminal approach allow for exact planning of the surgical approach.

[Congenital skull depression. Case report and review of the literature]. / Konnatale Schädelimpression. Fallbericht und Literaturübersicht.

A 40-week gestational age infant was delivered by cesarean section because of intense contractions and pathological fetal heart rate pattern. The umbilical artery pH was 7.03, Apgar scores were 1/4/7 at 1, 5 and 10 min of age. The 3,250-gram infant had a skull depression of 5 x 7 cm in the left temporal-parietal region with a depth of 1.5 cm. There were no edemas or hematomas in this area; neurological examination was normal. A CT scan did not show a fracture, but the cortex below the depression appeared slightly compressed. At the age of 11 days, the depressed part of the parietal squama was surgically elevated. The child was discharged in good condition 8 days later and remained well at a 6-month follow-up examination.