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PubMed1989

EEG asymmetries may be affected by cranial and brain parenchymal asymmetries.

The plagiocephaly index, an index that reflects an underlying anatomic asymmetry of the brain, was assessed in ten schizophrenic patients and its values were correlated with the lateral distribution of quantitatively evaluated EEG. The correlations between the index and alpha power at F7 were significant, positive for frontal asymmetry (frontal bulging) and negative for occipital flattening. We then studied ten normal subjects in an attempt to illuminate the contribution of several cephalic and cranial variables to the imbalance of alpha-afterdischarges (AD) of VEP recorded at O1-O2. The asymmetry index of AD was computed and correlated with asymmetries of CT-derived measures of occipital bone thickness, occipital lobe width, mastoid area, and sulcal asymmetry (the asymmetry of intraparietal sulcus location from the longitudinal fissure). With the exception of the sulcal variable all measures significantly covaried with alpha AD. These findings caution that it may be important to determine cranial and brain parenchymal asymmetries where brain laterality is pertinent to studies of EEG.

Adolescent↗
PubMed2000

[A case of Collet-Sicard syndrome caused by skull base metastasis of prostate carcinoma].

A case of Collet-Sicard Syndrome caused by skull base metastasis of prostate carcinoma is reported. A fifty-five years old man presenting multiple lymph node and bone metastases of prostate carcinoma was treated with LH-RH agonist and Flutamide, which induced transient decrease in serum PSA levels and size of lymph node metastases. After 8 months of the treatment, the patient started complaining headache, dysphagia and dysarthria. Brain CT and MRI demonstrated a soft tissue mass replacing left pyramidal bone and occipital bone around left jugular foramen. The tumor was diagnosed as skull base metastasis of the prostate carcinoma and was treated with 50Gy of radiation. The symptom improved after the radiation but died of the disease in 4 months. The autopsy revealed the skull base metastasis of the prostate carcinoma and the tumor was proved to be poorly differentiated adenocarcinoma, which was positively stained by anti-PSA antibody. The case showed cranial nerve palsy of IX to XII, which is usually called Collet-Sicard syndrome. This is the third case report of Collet-Sicard syndrome caused by the skull base metastasis of prostate carcinoma, and it is the first case in Japan.

Adenocarcinoma↗
PubMed1990

Ossification of the human fetal basicranium.

Previous investigations of prenatal development of the human cranium have not identified the sequence of its ossification. The purpose of the present study was to elucidate the pattern of skeletal maturity of the cranial bones in the midsagittal region anterior to the foramen magnum. This study is based upon a radiographic and histochemical investigation of midsagittal tissue blocks of the cranial bases of 73 human fetuses derived from the first half of the prenatal period. A marked regularity in the ossification pattern of the bones in the midsagittal part of the human cranium was observed. Ossification starts in the frontal bone. The sequence in which the next bones ossify is occipital bone, basisphenoid bone, presphenoid bone, and ethmoid bone. The material was divided into 7 maturity stages devised for this analysis. The stages were related to general fetal size (crown-rump length) and to general fetal maturation (composite number of ossified bones in hand and foot). Skeletal development of the median part of the human cranium is not strictly correlated with the size or the stage of general maturation of the fetuses. Knowledge of normal skeletal development is necessary for understanding anomalies of development.

Bone Development↗
PubMed1976

[Dura arteriovenous malformation of the posterior fossa-clinical and angiographical analysis of 6 cases].

Dural arteriovenous malformation of the posterior fossa was infrequently reported in the literatures. We presented 6 cases of dural arteriovenous malformation of the posterior fossa with the presentation of typical examples. Up to the end February, 1974, 119 cases of intracranial arteriovenous malformation were experienced in our clinic, in which there were 6 cases of dural arteriovenous malformation. The ages of our series ranged from 41 to 75 years old and 57 years old in average. Tinnitus and headache were two main symptoms which developed in most of the cases. As for the older symptoms, visual disturbance was seen in 4 cases, unilateral pulsating exophthalmos in 1 case and papilledema in 3 cases. There wers two cases which progressive dementia was developed by the cerebral anoxia due to arteriovenous shung. On examination, a pulsatile bruit was audible at the mastoid region in all cases and a thrill could be palpated along the occipital arteries. Many kinds of durl and/or tentorial arteries which were drained directly into the sinuses at the occipital portion as the feeding arteries were visualized angiographically. Moreover, the angiographical patterns of feeding arteries into the sinuses showed dynamic changes after the operation. As for the treatments, many kinds of surgery were carried out for the cases by the combination method of the next 6 ways. 1. ligation of external carotid artery 2. ablation of periosteum from occipital bone 3. occipital and/or suboccipital craniectomy 4. clipping of almost of all feeding arteries at dura mater and tentorium 5. ligation of threocervical trunk 6. ventriculo-atrial shunt or ventriculo-peritoneal shunt From our experiences, the most effective treatment is thought to be a direct closure of intradural arteriovenous shunt near the sinus at the occipital portion in the early stage.

Adult↗
PubMedDate not supplied

Occipital aneurysmal bone cyst: CT features.

A case of aneurysmal bone cyst arising from the lower occipital squama with intracranial extension is presented. The case is unique in that the cyst showed fluid levels on CT. Another peculiarity of this case was postoperative recurrence.

Bone Cysts↗
PubMed1996

Occipital morphology. An anatomic guide to internal fixation.

STUDY DESIGN: The authors present the results of an anatomic study of the human occiput to delineate appropriate screw placement sites. OBJECTIVES: Occipital bone morphologic characteristics were evaluated to determine whether significant variability exists and to determine the position of greatest bone thickness for safe and effective internal fixation. SUMMARY OF BACKGROUND DATA: New instrumentation and techniques for occipital fixation are being developed in response to concerns about occipital bone variability. Thirty cadaveric occiputs were evaluated to determine if such variability exists and the location of greatest bone thickness. Radial thickness, occipital locations, and gender differences, were determined. METHODS: Twenty-six skulls were sectioned sagittally to determine the contributions of the inner, middle, and outer tables to overall occipital thickness. The angle required to gain maximal cortical purchase was determined. Mean values and variance were analyzed statistically to determine variability and thickness. Data was plotted in three dimensions. Variability in morphologic features was minimal. RESULTS: The internal occipital protuberance-external occipital protuberance was thickest at 17.55 mm (SD = 3.18 mm) and was consistently located on the superior nuchal line 43 degrees from the horizontal skull base line. Bone thickness decreased radially from the central internal occipital protuberance position. Bone thickness above the superior nuchal line exceeded that below by 2.74 mm (P < 0.05) vertically and at the oblique positions (P < 0.05). Bone to the right of the midline was only 1 mm thicker than that to the left. Gender differences were minimal. The inner table contributed only 10% to overall occipital thickness. As occipital thickness decreased, the optimal purchase angle increased. CONCLUSIONS: Unicortical purchase at and above the superior nuchal line is warranted with a low risk of intracranial venous penetration. Internal fixation devices developed in response to occipital bone variability should be considered with respect to occipital bone thickness distributions. Attention to cervical morphologic characteristics should result in higher success rates in occipitocervical arthrodesis.

Bone Plates↗
PubMed2002

Median (third) occipital condyle.

Abnormalities of the craniovertebral junction, most of which are associated with the occipital bone, are of interest not only to anatomists but also to clinicians because many of these deformities produce clinical symptoms. The occipital bone in humans is formed by the fusion of the sclerotomes corresponding to the roots of the hypoglossal nerve. In lower vertebrates, the cranial half of the first cervical sclerotome forms a separate bone between the atlas and occipital bone, the proatlas; in man it may contribute to anomalous structures around the foramen magnum. One such structure, a median occipital condyle, which exhibited an articular facet for the odontoid process, was observed in an adult male skull at the anterior margin of the foramen magnum. This anomaly is discussed in light of available literature.

Adult↗
PubMed1999

Occipitocervical fixation using hooks and screws for upper cervical instability.

OBJECTIVES: Occipitocervical fixation is used for the treatment of nontraumatic upper cervical instabilities. To date, plates have been fixed with screws or wires. However, these devices are not indicated in the treatment of patients with severe osteoporosis or in instances of significant thinning of the occipital bone. We performed a clinical trial of a new type of fixation that uses cervical interlaminar hooks and occipital claws with hooks or with screws (CCD type; Sofamor-Danek, Roissy, France) for the treatment of nontraumatic upper cervical instabilities. METHODS: Five women and one man ranging in age from 28 to 72 years (average age, 54 yr) were thus treated. The CCD type material had two rod plates and hooks allowing the proper placement of interlaminar and occipital claws. The occipital plate can also be directly screwed to the bone. Occipital hooks were used in four patients. The other two patients, who had occipitocervical congenital abnormalities that required an occipitocervical opening and an additional dural enlargement, underwent occipital screw fixation because of the previous opening of the foramen magnum. A cancellous iliac autograft allowed the usual fusion. RESULTS: No postoperative complications were observed, and all patients experienced significant improvement of their neck pain. Four patients had neurological symptoms. The condition of two patients improved, and the condition of the other two stabilized. CONCLUSION: This report confirms the interest of the CCD method to correct all types of upper cervical instabilities, even in cases of unusual thinning of the occipital bone or in osteoporotic states.

Adult↗
PubMed1999

The thickness of the skull in Korean adults.

New instrumentation and techniques for skeletal fixation have been developed in response to concerns regarding variability of the skull base and the calvaria. The fear of intracranial penetration has limited the use of internal or external fixation to the skull base and the calvaria. Despite potential clinical usefulness, limited anthropometric data have been reported on the skull base and the calvaria. The purpose of this study was to measure the average thickness of various points of the skull base and the calvaria of Korean adults. Fifty-one Korean adult skull bases and calvaria, which were cut 2 cm above the supraorbital margin anteriorly and 2 cm above the inion posteriorly, were measured in this study. Thickness of 13 clinically important points were measured with a Teclock GM-21 Calipergauge (Teclock Co., Tokyo, Japan). The mean thickness of the two opposite sides were compared using paired t-tests. They did not differ significantly from the others except for three points. Frontal bone A (located 1 cm above the supraorbital margin and 1.5 cm lateral to the midline) was 6.35 +/- 2.88 mm, frontal bone B (located at the midpoint of the frontal midpoint and the frontoparietal suture on the cut edge) was 5.24 +/- 1.50 mm, frontal bone C (located at the midpoint of the vertex and frontal bone B) was 6.63 +/- 1.77 mm, the pterion was 3.19 +/- 0.85 mm, the midpoint of the squamous temporal was 1.96 +/- 0.65 mm, parietal bone A (located 1.5 cm below the middle meningeal groove) was 3.99 +/- 1.11 mm; parietal bones B and C (divided at the distances between the frontoparietal suture and the occipital midpoint with a ratio of 1:3 and 2:3 respectively on the cut edge) were 4.71 +/- 1.06 mm and 5.35 +/- 0.91 mm respectively, occipital bone A (located 1.5 cm posterolateral from the foramen magnum) was 2.31 +/- 1.00 mm, occipital bone B (located 1.5 cm lateral to the midline and 0.5 cm above the inion) was 5.41 +/- 1.50 mm, occipital bone C (located occipital to the midpoint and 2 cm above the inion) was 8.2 +/- 1.67 mm, the orbital roof was 1.37 +/- 1.08 mm, and the orbital lateral wall was 2.25 +/- 1.06 mm. The data give practical information for determining the position and depth for safe and effective internal or external fixation during craniofacial procedures.

Adult↗
PubMed1992

[Congenital malformation of the skeleton in Weiser-Maples guinea pigs].

Some abnormalities were observed in the occipital bone, cervical vertebrae and thoracic vertebrae of Weiser-Maples guinea pigs. In the occipital bone, the medial basilar impression was suggested to occur in 40 (32.8%) out of 122 animals. The basilar impression was classified into right, left and both side types and observed in 24, 11 and 5 animals, respectively. The basilar impression was known to be accompanied in human with some anomalies such as platybasia, Klippel-Feil syndrome, deformation of foramen magnum and so-on. These anomalies were also observed in guinea pigs. The fusion of the axis with the 3rd cervical vertebra was observed in 12 (10.5%) out of 114 animals. The deformation was sometimes observed in the temporal, interparietal, atlas and axis as well as the occipital bone. The fusion of the 7th cervical vertebra with the 1st thoracic vertebra was found in 46 (51.7%) out of 89 animals. This fusion was thought to have no relation with the basilar impression. Weiser-Maples guinea pigs are now in 19 generations of sibmating. Because these abnormalities as mentioned above are all thought to be inherited, the selective breeding will make Weiser-Maples guinea pigs suitable for the study of the basilar impression.

Animals↗
PubMed2004

The sequence in appearance and disappearance of impressiones gyrorum cerebri and cerebelli.

We investigated the sequence and the intensity in the appearance and the disappearance of the impressiones gyrorum cerebri and cerebelli, of juga cerebralia and cerebellaria and of juga cerebellaria interlobularia in the collection of 34 macerated and disarticulated skull bones from the newborn to 30 years of age (68 specimens/halves of skulls) and 19 skulls in the period from 30 to 80 years of age (38 specimens). Juga cerebralia on the squama of the temporal bone and cerebral lamina of the frontal bone appeared already in the course of the first year of life, much earlier than cited in the literature. The intensity of the development of juga cerebralia increased to the third decade. After that age, the intensity decreased gradually, and the juga cerebralia disappeared completely in parietal bones, in the cerebral fossae of the occipital bones and finally in most cases also on the cerebral lamina of the frontal bones. Juga cerebellaria and impressiones gyrorum cerebelli appeared in the middle of the second year of age and persisted to the ten years of age, which coincides with the closure of the fissures among the parts of the occipital bone. Jugum cerebellare intersemilunare appeared in the first year of life and persisted in its complete length, or interrupted in different sections of its course, during the whole life. The intensity in appearance of juga is partly influenced by the increasing thickness of the diploe.

Adult↗
PubMed2002

Bone SPECT imaging of patients with internal derangement of temporomandibular joint before and after splint therapy.

OBJECTIVE: Temporomandibular joint (TMJ) patients with disc displacement without reduction have a misaligned disc-condyle structural relation. As the condition becomes chronic, painful osteoarthritic changes may occur. For these patients, splint therapy may help to position the condyle to a more structurally compatible and functional position and to decrease the loading force of articular surfaces. The aim of this study was (1). to evaluate osseous reactions and pain relief in patients with disc displacement without reduction after splint therapy and (2). to use single photon emission tomography (SPECT) bone imaging to compare the results with the opposite joint of the patient. STUDY DESIGN: Twelve patients, who presented with pain involving the TMJ and limited mouth opening and were confirmed by soft tissue imaging as having disc displacement without reduction, were included in the study. Each patient underwent bone SPECT imaging, after which semiquantitative evaluation of transaxial images was conducted. The ratios of affected TMJ to nonaffected TMJ, affected TMJ to occipital bone, and nonaffected TMJ to occipital bone were calculated. After 6 months of splint therapy, bone SPECT examinations were repeated. RESULTS: Before splint therapy, the ratios of affected TMJ to nonaffected TMJ and of affected TMJ to occipital bone were found to be significantly higher than the ratios after splint therapy (P < 0.005). CONCLUSION: Six-month splint therapy has a positive effect on the osseous reaction and pain related to internal derangements of TMJs.

Adolescent↗
PubMed2006

Identification of greater occipital nerve landmarks for the treatment of occipital neuralgia.

Important structures involved in the pathogenesis of occipital headache include the aponeurotic attachments of the trapezius and semispinalis capitis muscles to the occipital bone. The greater occipital nerve (GON) can become entrapped as it passes through these aponeuroses, causing symptoms of occipital neuralgia. The aim of this study was to identify topographic landmarks for accurate identification of GON, which might facilitate its anaesthetic blockade. The course and distribution of GON and its relation to the aponeuroses of the trapezius and semispinalis capitis were examined in 100 formalin-fixed adult cadavers. In addition, the relative position of the nerve on a horizontal line between the external occipital protuberance and the mastoid process, as well as between the mastoid processes was measured. The greater occipital nerve was found bilaterally in all specimens. It was located at a mean distance of 3.8 cm (range 1.5-7.5 cm) lateral to a vertical line through the external occipital protuberance and the spinous processes of the cervical vertebrae 2-7. It was also located approximately 41% of the distance along the intermastoid line (medial to a mastoid process) and 22% of the distance between the external occipital protuberance and the mastoid process. The location of GON for anaesthesia or any other neurosurgical procedure has been established as one thumb's breadth lateral to the external occipital protuberance (2 cm laterally) and approximately at the base of the thumb nail (2 cm inferior). This is the first study proposing the use of landmarks in relation to anthropometric measurements. On the basis of these observations we propose a target zone for local anaesthetic injection that is based on easily identifiable landmarks and suggest that injection at this target point could be of benefit in the relief of occipital neuralgia.

Aged↗
PubMed1986

Observations on the bony bridging of the jugular foramen in man.

The anatomical nature and pattern of incidence of bony bridging of the jugular foramen was investigated using 64 fetal crania aged nine months to term and 222 adult crania of Japanese. In addition, the region of the jugular foramen of an adult cadaver was carefully dissected in order to clarify the relationship between the cranial nerves passing through the jugular foramen and the intrajugular processes of the jugular foramen. The general conclusions concerning the anatomical nature of the bony bridging of the jugular foramen were as follows. (1) The intrajugular process of the temporal bone is situated posterior to the triangular depression (as described in Gray's Anatomy) of the petrous part. (2) The bony bridging of the jugular foramen is established by the contact of the intrajugular process of the temporal bone with the bony process of the occipital bone projecting either from just above the hypoglossal canal (Type I) or from posterior to the hypoglossal canal (Type III). (3) If both the processes of the occipital bone reach the intrajugular process of the temporal bone simultaneously, the jugular foramen is divided into three compartments. (4) In the case of Type I bridging, the anteromedial compartment transmits the glossopharyngeal nerve, while the posterolateral compartment gives passage to the vagus nerve, the accessory nerve and the internal jugular vein. (5) In the case of Type II bridging, the anteromedial compartment contains the glossopharyngeal, vagus and accessory nerves, and the posterolateral compartment transmits the internal jugular vein. (6) When tripartite division of the jugular foramen occurs, the anteromedial compartment transmits the glossopharyngeal nerve, the middle compartment contains the vagus and accessory nerves, and the posterolateral compartment transmits the internal jugular vein. Concerning the pattern of incidence of jugular foramen bridging in the Japanese fetal and adult cranial series, this is similar to that of the bony bridging of the hypoglossal canal. The fact that almost all the cases of bridging of the jugular foramen are already established by the end of fetal development must serve as a strong indication that this trait can be used effectively for anthropological population studies.

Adult↗
PubMed2003

Atlantoaxial rotatory fixation secondary to tuberculosis of occiput: a case report.

STUDY DESIGN: A case of nontraumatic rotatory fixation of the atlantoaxial joint associated with tuberculosis of the occipital bone in an adult. OBJECTIVES: To report a rare case of atlantoaxial rotatory subluxation associated with tuberculosis of the occipital bone in an adult and to discuss the mechanism of fixation. SUMMARY OF THE BACKGROUND DATA: Atlantoaxial rotatory fixation in adults is rare and has been reported due to variety of causes. To the authors' best knowledge no case has been reported secondary to tuberculosis of the skull bone. METHODS: A 20-year-old male presented with resistant torticollis with a duration of 5 months. RESULTS: The patient had type 1 atlantoaxial rotatory fixation secondary to tuberculosis of the occipital bone. The subluxation was partially reduced by conservative means, and healing of the occiput lesion was achieved. Thereafter, the patient had no restriction of cervical spine motion and had no reoccurrence of subluxation at a follow-up of one and a half years. CONCLUSIONS: Effusion in the atlantoaxial joint secondary to infection in the occiput due to close proximity with the joint led to the laxity of ligaments and contributed to the subluxation.

Adult↗
PubMed1997

Microsurgical anatomy of the transcondylar, supracondylar, and paracondylar extensions of the far-lateral approach.

Despite a large number of reports of the use of the far-lateral approach, some of the basic detail that is important in safely completing this exposure has not been defined or remains poorly understood. The basic far-lateral exposure provides access for the following approaches: 1) the transcondylar approach directed through the occipital condyle or the adjoining portions of the occipital and atlantal condyles; 2) the supracondylar approach directed through the area above the occipital condyle; and 3) the paracondylar exposure directed through the area lateral to the occipital condyle. The transcondylar approach provides access to the lower clivus and premedullary area. The supracondylar approach provides access to the region of, and medial to, the hypoglossal canal and jugular tubercle. The paracondylar approach, which includes drilling of the jugular process of the occipital bone in the area lateral to the occipital condyle, provides access to the posterior portion of the jugular foramen and to the mastoid on the lateral side of the jugular foramen. In this study, the anatomy important to completing the far-lateral approach and these modifications was examined in 12 cadaveric specimens. In the standard posterior and posterolateral approaches, an understanding of the individual suboccipital muscles is not essential. However, these muscles provide important landmarks for the far-lateral approach and its modifications. Other important considerations include the relationship of the occipital condyle to the foramen magnum, hypoglossal canal, jugular tubercle, the jugular process of the occipital bone, the mastoid, and the facial canal. These and other relationships important to completing these exposures were examined in this study.

Adult↗
PubMed2006

Three-dimensional ultrasound in the prenatal diagnosis of cleidocranial dysplasia associated with B-cell immunodeficiency.

A patient with a singleton pregnancy was referred for three-dimensional ultrasonography (3DUS) at 18 + 3 weeks for suspected hypomineralization of the skull bones and absence of the nasal bones. Three-dimensional rendered images of the fetal skull revealed widening of the coronal sutures, absence of the squamous portion of the temporal bone, and absence of the occipital bone, except for two areas of ossification. In addition, a fractured right clavicle was identified. The remainder of the fetal anatomy was normal and biometry was appropriate for gestational age. Genetic amniocentesis revealed a 46,XX fetal karyotype. Family history was positive for a 5-year-old sibling with an open anterior fontanelle. Cleidocranial dysplasia was suspected. A female neonate was delivered by elective repeat Cesarean section at 40 + 3 weeks of gestation without complications and discharged home 3 days after delivery. Prenatal diagnosis was confirmed by physical and radiological evaluation. The infant died at 8 weeks of age due to respiratory syncytial virus pneumonia secondary to B-cell deficiency. RUNX2 mutations were not detected by molecular analysis. There are three relevant aspects to this case: (1) clear visualization of the widened fontanelles and hypomineralized occipital bones was possible with the use of 3DUS; (2) a clavicular fracture was identified in utero with combined high-resolution two-dimensional and 3DUS; and (3) although absence of the nasal bones is most commonly observed in fetuses with chromosomal disorders (e.g. trisomy 21 and trisomy 18), a careful examination of the skeleton should be considered in fetuses with absent nasal bones and a normal karyotype.

Adult↗