[A case of infantile anaplastic astrocytoma treated with surgery and chemotherapy]

A 5-month-old girl presented with enlargement of the head circumference. Neurological examination revealed right hemiparesis and bulging of the anterior fontanel. T1-weighted magnetic resonance imaging with gadolinium DTPA showed a well-enhanced, huge tumor extending from the left frontal lobe to the parietal lobe. Cerebral angiography showed the main feeding arteries were the central sulcus artery and the posterior parietal artery. The tumor was totally removed using a sulcotomy and temporary clipping of these feeding arteries to control bleeding. The histological diagnosis was anaplastic astrocytoma. Postoperative radiation therapy was avoided so as to prevent the side effect of radiation therapy such as mental retardation and growth impairment. Chemotherapy using VP-16 and CDDP was given every six months as adjunct therapy. No tumor recurrence has been recognized for over a period of 2 years and 5 months after surgery and growth and mental development have been satisfactory. Total removal using great care not to damage neurological function followed by postoperative chemotherapy is the treatment of preference to obtain good prognosis and quality of survival in infant with such tumors.

Painful generalised clonic and tonic-clonic seizures with retained consciousness

Two patients in whom consciousness and memory were retained during bilateral clonic or tonic-clonic seizures are reported on, and three patients reported on previously are reviewed. Ictal semiology differed from myoclonic and supplementary motor seizures, which are other seizure types characterised by bilateral motor movements and retained awareness. In the two new patients ictal pain was a prominent feature. It is proposed that propagation of seizure activity may be confined to the sensorimotor areas bilaterally while sparing the neural structures involved in maintaining consciousness and in processing language and memory. This unusual type of seizure may be misdiagnosed as a pseudoseizure. Detailed description of the ictal events and further laboratory evaluation including video-EEG monitoring may be necessary to make the distinction.

Recurrent self-inflicted craniocerebral injury: case report and review of the literature

Self-inflicted craniocerebral injuries have been reported exclusively in mentally disturbed patients and criminals. We report a 28-year-old man with a severe mental disorder who initially hammered a nail into his brain and subsequently repeatedly inserted foreign objects into his brain. The literature is reviewed and the surgical and psychiatric management discussed.

Results and complications after reoperation for failed epilepsy surgery in children

The seizure outcome and neurological outcome in children who undergo reoperation for failed epilepsy surgery have not been well documented. This retrospective study evaluated 20 children who underwent a second resective surgery for recurrent seizures. Four categories of patients were identified: (1) extension of the initial resection was performed in 8 patients; (2) 5 patients underwent lobectomy or corticectomy in a region remote from the original surgical site; (3) multilobar resection which may have included further resection of the initial procedure was accomplished in 4 patients; (4) hemispherectomy was performed in 3 patients. Patients with reoperation in the same lobe as the first procedure (group 1) had a 62% seizure-free rate, while 44% of patients in groups 2 and 3 were free from seizures at follow-up evaluation. Patients undergoing hemispherectomy had a 67% seizure-free rate. Significant unexpected neurological deficits occurred in 3 patients who underwent multilobar resection at reoperation. Complications included motor and language deficits. Reoperation for intractable partial epilepsy is beneficial in selected children. Patients who require multilobar resections may have higher risk of postoperative neurological deficit than those patients with reoperation in one lobe. These factors may be useful in counseling parents of children considering reoperation for recurrent epilepsy.

Surgical techniques and the results of a fronto-temporo-parietal combined indirect bypass procedure for children with moyamoya disease: a comparison with the results of encephalo-duro-arterio-synangiosis alone

We recently treated children with Moyamoya disease using a fronto-temporo-parietal combined indirect bypass procedure. Three different indirect bypass procedures (frontal EMAS, EDAS, EMS) were simultaneously carried out at three different sites. We thus treated 16 sides in 12 pediatric patients with Moyamoya disease using this method. Both the collateral formation and the improvement in the clinical symptoms were evaluated postoperatively. These results were then compared with those of the patients treated by EDAS alone. The postoperative collateral formation was more extensively seen in the patients treated with the combined bypass procedure than in those treated by EDAS alone. The improvement in ischemic symptoms was also better in the patients treated by the combined indirect bypass procedure. We therefore conclude that the combined indirect bypass procedure is more effective than EDAS alone.

Germinoma in cerebral hemisphere associated with Down syndrome

A Down syndrome patient with germinoma developing in the cerebral hemisphere is reported. A review of the literature yielded only 14 cases of Down syndrome with brain tumors, including our case. This finding of brain tumors in patients with Down syndrome may reflect chance occurrence. However, it is of interest in this regard that in 6 of the 14 (43%) reported cases the lesions were intracranial germ cell tumors.

Combined direct and indirect reconstructive vascular surgery on the fronto-parieto-occipital region in moyamoya disease

Between January 1992 and December 1995, eight patients with Moyamoya disease, aged from 2 to 39 years, underwent encephalo-duro-arterio-myo-synangiosis (EDAMS) on the frontal region, superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis combined with encephalo-myo-synangiosis (EMS) on the parietal region and encephaloduro-arterio-synangiosis (EDAS) on the occipital region using the frontal and parietal branch of the STA and the occipital artery, respectively. The development of postoperative collateral formation was assessed by carotid angiography and the improvement of clinical symptoms was evaluated for over 1 year after the bypass surgery. Of the 13 sides which underwent EDAMS and STA-MCA anastomosis with EMS, 11 sides resulted in extensive revascularization on the frontoparietal region and two sides showed localized collaterals, whereas EDAS on the occipital region demonstrated extensive and localized revascularization in each four sides and no evidence of revascularization in two sides among ten sides which underwent the EDAS. The clinical improvement due to the combined reconstructive surgery was very excellent in the reduction of the incidence of transient ischemic attacks (TIA) and reversible ischemic neurologic deficits (RIND).

[A neuropsychological study on a patient with the resection of the right lateral frontal lobe]

We report a patient who underwent a resection of the right lateral frontal lobe after a venous thrombosis of the superior sagittal sinus. The patient showed inertia, obsessive-compulsive behavior and disinhibition two weeks after the operation and hyperlogia and hypergraphia four weeks later, all of which disappeared within six weeks. General intelligence, language and memory were consistently preserved, though the scores of the performance IQ and the visual memory were relatively decreased. A few months after the operation emotional and personality change such as impatience and apathy became evident. We suggest that the right lateral prefrontal area is concerned with personality and behavior and that the widespread resection holds general intelligence, language and memory within normal range but relatively decreases non-verbal cognitive function that requires manual responses.

Frontal glioma presenting as anxiety and obsessions: a case report

A 53-year-old gentleman is described, who presented with acute onset of anxiety and obsessional symptoms. The clinical picture was complicated by the presence of mild alcohol withdrawal symptoms and history of excessive drinking for 20 years. A month later, he developed right hemiparesis. CT scan revealed a left frontal tumour, and on histology this was found to be Grade 4 astrocytoma.

Magnetic source imaging combined with image-guided frameless stereotaxy: a new method in surgery around the motor strip

OBJECTIVE

In this study, information about the localization of the central sulcus obtained by magnetic source imaging (MSI) was intraoperatively translated to the brain, using frameless image-guided stereotaxy. In the past, the MSI results could be translated to the surgical space only by indirect methods (e.g., the comparison of the MSI results, displayed in surface renderings, with bony landmarks or blood vessels on the exposed brain surface).

METHODS

Somatosensory evoked fields were recorded with a MAGNES II biomagnetometer (Biomagnetic Technologies Inc., San Diego, CA). Using the single equivalent current dipole model, the localization of the somatosensory cortex was superimposed on magnetic resonance imaging with a self-developed contour fit program. The magnetic resonance image set containing the magnetoencephalographic dipole was then transferred to a frameless image-guided stereotactic system. Intraoperatively, the gyrus containing the dipole was identified as the postcentral gyrus, using neuronavigation, and the next anterior sulcus was regarded as the central sulcus. With intraoperative cortical recording of somatosensory evoked potentials, this assumption was verified in each case.

RESULTS

In all cases, the preoperatively assumed localization of the central sulcus and motor cortex with MSI agreed with the intraoperative identification of the central sulcus using the phase reversal technique.

CONCLUSION

The combined use of MSI and a frameless stereotactic system allows a fast orientation of eloquent brain areas during surgery. This may contribute to a safer and more radical surgery in lesions adjacent to the motor cortex.

The effect of goal-subgoal conflict on planning ability after frontal- and temporal-lobe lesions in humans

Twenty-one patients with unilateral prefrontal cortical neurosurgical lesions (11 left and 10 right) and 38 patients with unilateral temporal lobectomy (19 left and 19 right) were compared to 44 matched control subjects on their performance on the 3-D Computerized Tower of Hanoi (3-D CTOH) test. The problems were split into those with or without a significant goal-subgoal conflict determined by whether the correct first move in each problem took the subject apparently away or towards the final goal state. The left frontal lesion and right temporal lobectomy groups were significantly impaired on problems with goal-subgoal conflicts. In the left frontal group, this deficit was confined to earlier four-move problems, whereas the right temporal group showed a more general deficit on later five-move problems. The left frontal lesion deficit is explained in terms of an inability to inhibit the response compatible with achieving a final goal, whereas the impairment in the right lesion group was related to a specific impairment in spatial memory.

Intrinsic epileptogenesis of hypothalamic hamartomas in gelastic epilepsy

Hypothalamic hamartomas and gelastic seizures are often associated with cognitive deterioration, behavioral problems, and poor response to anticonvulsant treatment or cortical resections. The origin and pathophysiology of the epileptic attacks are obscure. We investigated 3 patients with this syndrome and frequent gelastic seizures. Ictal single-photon emission computed tomography performed during typical gelastic seizures demonstrated hyperperfusion in the hamartomas, hypothalamic region, and thalamus without cortical or cerebellar hyperperfusion. Electroencephalographic recordings with depth electrodes implanted in the hamartoma demonstrated focal seizure origin from the hamartoma in 1 patient. Electrical stimulation studies reproduced the typical gelastic events. Stereotactic radiofrequency lesioning of the hamartoma resulted in seizure remission without complications 20 months after surgery. The functional imaging findings, electrophysiological data, and results of radiofrequency surgery indicate that epileptic seizures in this syndrome originate and propagate from the hypothalamic hamartoma and adjacent structures.

Visuo-motor conditional associative learning after frontal and temporal lesions in the human brain

It has been shown that damage to the human lateral frontal cortex results in a severe impairment on conditional associative tasks requiring learning of arbitrary associations between a set of stimuli and a set of responses (Petrides, M., Neuropsychologia, 1985, 23, 601-614; 1990, 28, 137-149). In these studies, which first demonstrated the impairment after frontal lesions, training was by a trial-and-error procedure, during which the subject performed the various responses when a given stimulus was presented and the experimenter provided feedback until the correct response was performed. In the present experiment, patients with unilateral frontal- or temporal-lobe excisions were tested on a visuo-motor conditional associative task with a modified procedure. The subjects had to learn arbitrary associations between a set of coloured stimuli and a set of hand postures. Training in the present experiment consisted of a series of demonstration trials followed by test trials. In the demonstration trials, the experimenter showed the subject the associations between the stimuli and the responses and, in the test trials that followed, the subject was tested on these associations. If an error was made on the test trials, the correct response was demonstrated by the experimenter. Despite these changes in the training procedure, namely the demonstration of the stimulus-response associations and the provision of the correct response immediately following an error, patients with left or right frontal-lobe excisions were severely impaired in learning this task. These findings, together with those of the earlier studies (Petrides, M., Neuropsychologia, 1985, 23, 601-614; 1990, 28, 137-149), demonstrate that the impairment in conditional learning after frontal lesions is not dependent on the type of the training procedure and therefore that it reflects a specific impairment in learning.

Effects of lesions invading the postcentral gyrus on somatosensory thresholds on the face

Patients with unilateral removals from either the parietal, frontal or temporal lobe and normal control subjects were examined on three tests of tactile sensibility. The patients with surgical excisions from the parietal lobe were subdivided into two groups: those whose lesions invaded the face area in the primary sensory cortex and those whose lesions spared this area. A significant percentage of patients with lesions that invaded the face area had mild to severe sensory deficits on the side of the face contralateral to the lesion. A much smaller number of patients had deficits on the ipsilateral side. Lesions to the face area in the primary sensory cortex were, however, associated with a lower incidence of severe and persistent sensory deficits when compared to previous results on the effects of lesions to the hand area on the sensory capacity of the hand. These results suggest that there is some preservation of sensory function after damage to the face area in the primary sensory cortex, presumably due to the bilateral representation of the face.

Categorical and dimensional decoding of emotional intonations in patients with focal brain lesions

The present study attempts to elucidate whether cerebral brain lesions differentially affect the crossmodal decoding of emotional intonations in semantically meaningless sentences. Forty patients with well-documented lesions and 12 matched hospital controls participated in the study. Twenty-one had left brain damage (LBD: 12 with anterorolandic (anterior) and 9 with retrorolandic-infrasylvian (posterior) lesions); 19 had right brain damage (RBD: 12 anterior, 7 posterior lesions). The decoding of emotion categories was measured using (a) multiple choice of verbal labels and (b) matching one emotional vocalization (joy, fear, sadness, or anger) with two choice facial expressions. Crossmodal dimensional decoding was assessed by matching vocalizations with two facial expressions with regard to emotional valence or arousal. Results indicate that labeling was reduced in all lesion groups as compared to that in controls. Crossmodal categorical recognition was impaired in RBD, whereas LBD performance was comparable to controls. However, in the dimensional decoding task, a reduced recognition of valence in LBD and arousal in RBD was observed. An analysis of localizational subgroups revealed that subjects with left ventral frontal lesions, which in part extended into the adjacent right hemisphere, were predominantly impaired in the crossmodal identification of valence, whereas right temporoparietal lesions affected arousal decoding. Our results suggest that lateralized lesions may differentially affect the crossmodal recognition of dimensional concepts such as valence and arousal.

Is there a superior occipitofrontal fasciculus? A microsurgical anatomic study

OBJECTIVE

Using a fiber-dissection technique, our aim was to expose and study the myelinated fiber bundles of the brain to achieve a clearer conception of their configurations and locations. During the course of our study, the superior occipitofrontal fasciculus became the focus of our interest. Many publications have defined this as a bundle of association fibers, located between the corpus callosum and the caudate nucleus, that connects the frontal and occipital lobes. By examining this area using fiber dissection, we realized that the descriptions of the anatomy are inadequate; thus, we focused on the elucidation of the anatomic structures of this region and, in particular, that known as the superior occipitofrontal fasciculus.

METHODS

Twenty previously frozen, formalin-fixed human brains were dissected under the operating microscope using the fiber-dissection technique.

RESULTS

On coronal sections of the brain, a structure on the superolateral aspect of the caudate nucleus usually has been identified as the superior occipitofrontal fasciculus. However, our fiber dissections revealed that this structure is the superior thalamic peduncle, that it is composed of projection fibers rather than association fibers, and that it does not interconnect the occipital and frontal lobes.

CONCLUSION

The structures of the brain are better understood when the fiber-dissection technique is used to explore their configurations and locations. The resulting information is especially beneficial for planning strategies and tactics of neurosurgical procedures.

Resection of frontal encephalomalacias for intractable epilepsy: outcome and prognostic factors

PURPOSE

Because focal encephalomalacia is an important cause of medically intractable partial epilepsy and few studies have evaluated the efficacy and the safety of resecting focal-encephalomalacias to improve seizure control, we studied a cohort of 17 consecutive patients who underwent resection of encephalomalacias in the frontal lobes as a treatment of their intractable epilepsy.

METHODS

We evaluated several factors for their value in predicting postsurgical seizure control. Pre- and postsurgical magnetic resonance imaging (MRI) scans were reviewed independently by 2 blinded investigators.

RESULTS

At a median of 3 years of follow-up (range 0.6-7.5 years), 12 patients (70%) were seizure-free or had only rare seizures. The presence of a focal fast frequency discharge (focal ictal beta pattern) at the beginning of seizures on scalp EEG was predictive of seizure-free outcome (p = 0.017), even among patients who had complete resection of their encephalomalacias (p = 0.016). There was no significant differences in outcome with regard to age at the time of the injury that caused encephalomalacia, interval between injury and onset of seizures, duration of presurgical seizure history, presurgical seizure frequency, age at surgery, or the completeness of encephalomalacia resection. The analysis regarding completeness of encephalomalacia resection almost reached significance, suggesting that it may also be an important predictive factor (p = 0.051).

CONCLUSIONS

We conclude that surgery is a very effective treatment for intractable frontal lobe epilepsy (FLE) secondary to encephalomalacias. Patients are more likely to become seizure-free if they have a focal ictal beta discharge on their scalp EEG. Complete resection of the encephalomalacia should be attempted, since our results suggest that this may be a favorable predictive factor. Moreover, the operative strategy for our patients entailed, whenever possible, complete resection of the encephalomalacias and of the adjacent electrophysiologically abnormal tissues.

The anatomical variations of sylvian veins and cisterns

The anatomical variations of sylvian vein and cistern were investigated during the pterional approach in 750 operative cases with different pathologies. All patients were operated on at the Neurosurgical Department of Ataturk University Medical School, Erzurum, Turkiye. The patients underwent surgery for the lesions necessitating the right or left pterional approach. The findings were recorded during surgical intervention and observed through the operative sketches of the pathologies, the slides, and videotapes of the operations. In our study, we surgically classified the variations of sylvian vein, according to its branching and draining patterns. Type I: The fronto-orbital (frontosylvian), fronto-parietal (parietosylvian) and anterior temporal (temporosylvian) veins drain into one sylvian vein. Type II: Two superficial sylvian veins with separated basal vein draining into the sphenoparietal and Rosenthal's basal vein. Type III: Two superficial sylvian veins draining into the sphenoparietal and the superior petrosal veins. Type IV: Hypoplastic superficial sylvian vein and the deep one. Four types of sylvian vein variations were defined as follows. The type I was seen in 52.8% (n = 396), the type II was found in 19.2% (n = 144), type III was recorded in 18.2% (n = 137), and type IV, or hypoplastic and deep form was discovered in 9.8% (n = 73) of patients. The coursing of sylvian vein was in the temporal side (Temporal Coursing) in 62.4 percent of the cases (n = 469), in the frontal side (Frontal Coursing) in 25 % of the patients (n = 187) and in 9 percent of the cases (n = 67) in the deep localization (Deep Coursing). Only 3.6% of the cases (n = 27) showed Mixed Coursing. The variations of the sylvian cisterns were classified into three types, according to the relationships between the lateral fronto-orbital gyrus and the superior temporal gyrus. In Sylvian type, the frontal and temporal lobes are loosely (Sylvian Type A, wide and large) or tightly (Sylvian Type B, close and narrow) approximated on the surface thereby covering the substance of the sylvian cistern. In Frontal Type, the proximal part of the lateral fronto-orbital gyrus herniated into the temporal lobe. In Temporal Type, the proximal part of the superior temporal gyrus herniated into the lateral fronto-orbital gyrus. The variations of the sylvian cisterns in 750 patients with different pathologies, were as follows: in 47.7% (n = 358) Sylvian type A, in 27.2% percent (n = 204) Sylvian type B, in 16.3% (n = 122) frontal type and in 8.8% (n = 66) temporal type. We concluded that venous perfusion discorder of the brain is the most important factor during the pterional approach. Careful intraoperative assessment and protection of the sylvian vein, which is a surgical pitfall, is an indispensable part of the operation. The recognition of the anatomical variations of the sylvian vein and cistern, and the detailed knowledge of the microvascular relationships and the importance of preservation of this vein at that level, will allow the neurosurgeon, believing in the minimally invasive neurosurgical techniques, to construct a better and safer microdissection plan, to save time, and can prevent postoperative neurological deficits.

Surgical treatment for epilepsy: a retrospective Swedish multicenter study

The characteristics of patients suffering from drug resistant epilepsy, including the results of the preoperative evaluation and epilepsy surgery were retrospectively analyzed in a Swedish multicenter 10-year cohort of children and adults. Altogether 152 patients (65 children and 87 adults) treated during the period 1980-1990 in three epilepsy centers were included and followed-up 2 years after surgery. Median age at onset of seizures was 4 years for the children and 12 years for the adults. A localization related epilepsy was present in 85% of the children and in 95% of the adults. The mean number of seizure types in the children was 1.7 (range 1-4) and in the adults 1.8 (range 1-4). The median monthly seizure frequency was 52 and 15 for children and adults respectively. Resective surgery was performed in 143 cases (94 temporal, 31 extratemporal, 9 multilobar and 9 major resection procedures) and palliative procedures in 16 cases (13 callosotomies and 3 stereotactic amygdalotomies). Postoperative neurological deficits were detected in 9% of the patients after temporal lobe resections and in 15% of the patients after extratemporal and multilobar resection procedures. Two years after resective surgery 53% of the children and 49% of the adults were seizure free. Another 25% of the patients had a more than 50% reduction of seizure frequency. In the postoperative non seizure free group of patients there was a negative correlation between decrease in weighted seizure severity and decrease in seizure frequency. This finding stresses the need for including other parameters than seizure frequency when evaluating the outcome of epilepsy surgery.

Multiple subpial transection for control of epileptic seizures: effectiveness and safety

PURPOSE

To assess the efficacy and safety of multiple subpial transection (MST), a new technique in epilepsy surgery, alone and in combination with resection.

METHODS

MST was performed in 22 patients with intractable epilepsy, 10 of whom were treated with a combination of a resection and MST in functionally important cortex, 6 of whom were treated with a combination of a resection and MST performed outside functionally important cortex, and 6 of whom were treated with MST alone.

RESULTS

Of the 6 patients who received MST alone, none became seizure free and 4 showed > 50% reduction of all seizure types. In 2 patients, including 1 with Rasmussen's encephalitis, no change in seizure frequency or intensity occurred. Of the 16 patients in whom MST was combined with a resection, 9 (56%) became seizure free. Six of the remaining 7 patients showed > 95% reduction of all seizure types. Disappearance of epileptiform potentials in the postoperative EEG correlated significantly with complete relief from seizures. Subtle, permanent neurological deficits remained in 5 of 14 patients who received MST in functionally important brain areas.

CONCLUSIONS

Reduction of the seizure frequency was substantial in 4 of 6 patients who received MST alone, but complete seizure control was not observed. MST surrounding a lesionectomy may be a new surgical approach which would minimize the excised volume and improve seizure control.

[Surgical aspects of frontal lobe tumors]

The authors analyze possibilities and limitations of surgery in the treatment of frontal lobe tumors. They also stress the importance of microtechnique and propose notes of operative management.

Intrathecal morphine for postoperative analgesia following repair of frontal encephaloceles in children: comparison with intermittent, on-demand dosing of nalbuphine

STUDY OBJECTIVE

To determine the efficacy of lumbar intrathecal (i.t.) morphine in a dose of 0.02 mg/kg in providing analgesia following repair of frontal encephaloceles.

DESIGN

Prospective, open-label investigation of i.t. morphine with secondary comparison to a retrospective cohort.

SETTING

Metropolitan hospital in the Philippines.

PATIENTS

24 ASA physical status I and II children undergoing frontal encephalocele repair.

INTERVENTIONS

Following induction of general anesthesia. I.t. morphine (Group 1) was administered via single-shot technique or through a lumbar i.t. drain placed for cerebrospinal fluid drainage during the surgical procedure. Postoperative analgesia was assessed by visual analog score in patients greater than 5 years of age or a behavioral score in patients less than 5 years of age. The retrospective cohort received postoperative analgesia with intermittent doses of intravenous nalbuphine (Group 2).

MEASUREMENTS AND MAIN RESULTS

Group 1 had decreased postoperative analgesic requirements, decreased intraoperative inhalational anesthetic requirements, and a longer time to the first request for postoperative analgesia than Group 2. The time to the first request for postoperative analgesia was 16.0 +/- 9.1 hours in Group 1 and 1.6 +/- 1.2 hours in Group 2 (p < 0.0001). Six of 12 patients in Group 1 required no analgesic drugs during the first 24 postoperative hours while all 12 patients in Group 2 (p = 0.02) did require analgesic drugs during this period. The patients in Group 1 who did not require supplemental analgesic drugs maintained pain scores of 2 or less throughout the first 24 postoperative hours.

CONCLUSION

Lumbar IT morphine provides effective analgesia following repair of frontal encephaloceles in children and adolescents.

Glabellar approach: simplified midline anterior skull base approach

As a simplified microsurgical technique for lesions at the midline anterior skull base, a glabellar approach through a small incision (5 cm) between the eyebrows crossing the nasion was developed in four cadaver dissections. To determine the ideal positioning of the patient, the angle of the surgical trajectory was measured in the sagittal plane. In an effort to make an operation simple and accurate through this limited exposure, measurements were made in distance from the midline nasion to various intradural structures. Average distance from the midline point of the nasion (MPNa) to the midline of the tuberculum sella was 6.37 +/- 0.29 cm, 6.98 +/- 0.26 cm to the midline of the optic chiasm, and 8.00 +/- 0.11 to the lamina terminalis. In addition, measurements to other various anatomical landmarks were made. The angle of the line drawn from the MPNa to the midline of the tuberculum sella was 5.2 +/- 1 degrees against a line drawn between the lateral canthus and the tragus (LC-T) in the sagittal plane. Based upon this study, the positioning of the patient's head would be better if the LC-T line is positioned at 25 degree extension when the operating microscope is set at 20 degree inclination. Within 6 to 8 cm in depth from the MPNa, important landmarks are exposed without brain retraction. If surgical instruments are marked with ruler calibration, the depth of the surgical instruments will suggest the anatomical location. This glabellar approach has been used in three patients successfully. A brain retractor was not necessary and not used during the operations. This technique provides key exposures to the midline anterior skull base.