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Although the inferior petro-occipital vein has been recently used for vascular access to the cavernous sinus, few detailed descriptions of its anatomy are in the literature. We aimed to investigate the morphology and relationships of this vessel. Twelve latex-injected cadaveric heads (24 sides) were dissected to identify the inferior petro-occipital vein and anatomic details documented. The petro-occipital vein was identified on 83.3% of sides. Generally this vein united the internal carotid venous plexus to the superior jugular bulb. However, on 10% of sides, the anterior part of this vein communicated directly with the cavernous sinus, and on 15%, the posterior vein drained into the inferior petrosal sinus at its termination into the superior jugular bulb. The petro-occipital vein was separated from the overlying inferior petrosal sinus by a thin plate of bone. On 40% of sides, small venous connections were found between these two venous structures. The vein was usually larger if a nondominant transverse sinus was present. The overlying inferior petrosal sinus was smaller in diameter when an underlying inferior petro-occipital vein was present. On 20% of sides, the posterior aspect of the vein communicated with the hypoglossal canal veins. On three sides, diploic veins from the clivus drained into the inferior petro-occipital vein. The inferior petro-occipital vein is present in most humans. This primarily extracranial vessel communicates with intracranial venous sinuses and should be considered an emissary vein. Knowledge of this vessel's exact anatomy may be useful to cranial base surgeons and endovascular specialists.

Introduction. Subgaleal hemorrhage is a rare but potentially fatal birth trauma. It is caused by rupture of the emissary veins (connections between the dural sinuses and scalp veins), followed by the accumulation of blood between the epicranial aponeurosis and the periosteum. Usually, it is associated with instrumental delivery (vacuum extraction, forceps delivery), but it may also occur spontaneously, suggesting the possibility of congenital bleeding disorder. Case Outline. A full term male neonate was born at 40 weeks gestation by spontaneous vaginal delivery, with birth weight of 3,700 g. The Apgar scores were 9 and 10 at 1 and 5 minutes, respectively. At the age of 23 hours, the baby became pale and lethargic. Large fluctuant swelling on his head was noted. He developed severe anemia and hypovolemia as a result of massive subgaleal hemorrhage. After successful treatment, the baby fully recovered. Follow-up and further evaluation revealed hemophilia A as a result of a de novo mutation. Conclusion. This case illustrates that subgaleal hemorrhage may be the first presentation of hemophilia A. Infants without obvious risk factors for developing subgaleal hemorrhage should be evaluated for congenital bleeding disorder. Successful outcome in affected infants requires early diagnosis, careful monitoring and prompt treatment.

Background The clinical relevance of emissary veins (EVs) is often neglected. However, for posterior fossa approaches, especially in semisitting positions, these transosseous connections become potentially life threatening. Therefore, knowledge of the presence and configuration of EVs is essential in preoperative planning. We report on the use of preoperative computed tomography (CT) imaging techniques to visualize EVs reliably. Methods A total of 100 consecutive patients were evaluated by helical CT in bone window mode reconstructed using the standard technique (4.5-mm slices) and the high-resolution technique (1 mm) for the posterior fossa. The presence and size of the EVs, their entry point in the sigmoid sinus, their predilection site, and their visibility using either CT technique were evaluated. Statistical analyses included a comparison of the data from both sides of the head. Results We noted impressive anatomical variations (high standard deviations) in the number, size, and intraosseous length of the EVs among the study population and between the sides (right and left) of an individual patient; however, no statistical significance was observed for any of these parameters. The detection rate of EVs in thin-slice CT scans versus standard CT scans is significantly different ( p = 0.0001 on both sides). Conclusions Thin-slice CT is essential in the preoperative planning of posterior fossa approaches to identify the presence and the course of EVs, reducing preventable approach-related morbidity during surgery.

A detailed description of the anatomy of the central occipital emissary vein, its embryology, anatomy, and abnormal variations is not available in the literature. This is the first known case report. A 48-year-old female underwent cerebral angiography to rule out dural arterio-venous fistula. Her angiography revealed an abnormally large central occipital emissary vein originating from the torcula, penetrating the cranium and draining into the suboccipital venous plexus. We provide discussion of the case with a review of the related literature. This case and its attached radiological images introduce a new type of entity to the existing data about the cranial emissary veins.

Baldness can occur as a consequence of several causes. Temporary or permanent, cicatricial or not, a sign of a metabolic dysfunction or other disorders, alopecia requires, more than any other disease, a correct etiopathogenic understanding, both of its psychological impact and to avoid worsening due to an inadequate treatment.

The endovascular treatment of spontaneous dural cavernous sinus fistula (DAVF) can be accomplished by arterial approach, just with symptoms relief, or by numerous venous approaches through the inferior petrosal sinus, ophthalmic vein, anterior or posterior intercavernous sinus and facial vein. Our case suggests the approach to the cavernous sinus via the foramen ovale and emissary veins puncture as an alternative when there is no possibility of venous approach conventionally described. A 76-year-old woman presented with right conjunctival hyperemia, exophthalmos, intraocular pressure increasing and visual deficits in a period of six months. Angiographic diagnosis of spontaneous DAVF isolated from the cavernous sinus, Barrow Type C, with exclusive venous drainage through the superior ophthalmic vein. Endovascular treatment was performed under general anesthesia. Attempts to approach the cavernous sinus through the inferior petrosal sinus ipsilateral and contralateral intercavernous, facial vein and pterygoid plexus, as well as by dissection and direct puncture of the superior ophthalmic vein were not possible. An approach to the cavernous sinus was performed by puncturing the foramen ovale, catheterization of the emissary vein of the foramen ovale with occlusion of the fistula with microcoils. There was a symptomatic regression with gradual normalization of intraocular pressure, exophthalmos and conjunctival hyperemia in three months. The approach to the cavernous sinus through the foramen ovale and catheterization of the emissary cranial skull base vein is an exception and should be considered in cases of spontaneous and isolated DAVF not accessible by a conventional approach.

Objectives/Hypothesis: CHARGE (Coloboma of the eye, Heart defects, Atresia of the choanae, Retardation of growth and/or development, Genital and/or urinary abnormalities, and Ear abnormalities and/or deafness) syndrome is a genetic disorder with prominent otolaryngologic features including choanal atresia and inner ear malformations. Recent experience with venous malformations during cochlear implant surgery prompted this study to define the spectrum of venous abnormalities in CHARGE and their surgical implications in otology. Study Design: Retrospective review of medical and radiologic records from databases of patients with CHARGE syndrome from three tertiary care academic medical centers. Methods: Eighteen patients with CHARGE for whom temporal bone CT scans were available were included in the review. Results: Venous anomalies of the temporal bone were present in 10 of 18 (56%) patients. The most common were large emissary veins (n = 5). In two of these cases, these veins were associated with an ipsilateral a hypoplastic sigmoid sinus or jugular foramen. Other abnormalities included an aberrant petrosal sinus, venous lakes in proximity to the lateral venous sinus, condylar canal veins, and jugular bulb abnormalities, including a high riding bulb obscuring the round window niche and a dehiscent jugular bulb. In four of six patients undergoing cochlear implantation, the course of the aberrant vessel necessitated a change in the surgical approach, either during mastoidectomy or placement of the cochleostomy. Conclusions: Temporal bone venous abnormalities are a common feature in CHARGE syndrome. The pattern of venous abnormality suggests that there is a failure of the sigmoid sinus/jugular bulb to fully develop, resulting in persistence of emissary veins. Recognition of these abnormal venous structures during otologic surgery is critical to avoiding potentially catastrophic bleeding. Laryngoscope, 2012

Emissary veins are valveless veins which pass through the cranial apertures and connect the dural venous sinuses and the extracranial veins. The clinical importance of emissary veins is increasingly being appreciated. Some emissary veins like the petrosquamosal sinus and mastoid emissary vein may cause significant bleeding during middle ear and skull base surgeries. A dilated mastoid emissary vein or condylar emissary vein can sometimes be a rare cause of tinnitus. Radiological identification of these venous channels has been described in recent years and assumes significance in light of their clinical importance. We describe the CT and MRI findings of a rare case that had persistence of multiple emissary veins and presented clinically with tinnitus. The radiological findings included a dilated left mastoid emissary vein, bilateral petrosquamosal sinuses, posterior condylar veins, occipital emissary veins and an intrapetrous venule. The left petrosquamosal sinus had an unusual origin from the dilated mastoid emissary vein. The patient also had major anomalies of posterior fossa venous sinuses which are discussed. A relevant review of literature is included.

The petrosquamosal (PSS) is an embryonic emissary vein of the temporal bone in humans and connects the intra- and extracranial venous networks. Few reports in the recent literature provide detailed descriptions of PSSs that are found before or during surgeries. We report the presence of PSS in two patients with chronic otitis media. An abnormal vessel was found originating from the sigmoid sinus of each patient. The vessels coursed anteroinferiorly over the superior portion of the temporal bone and terminated near the posterior part of the temporomandibular joint. The clinical significance of PSS and a brief literature review are presented.

Application of medicated oils on scalp had been practiced for centuries in the Ayurvedic system of medicine in diseases associated with the central nervous system. It is possible that the effectiveness of the therapy may be a result of targeted delivery of active compounds to the brain transcranially. Evidence also comes from two previous studies with positive results on brain targeted transcranial delivery of methadone base and diazepam on rat models. Possibility of transcranial drug delivery was investigated in healthy human volunteers using electroencephalography techniques by assessing the ability of transcranially administered diazepam in bringing about b activity in the electroencephalographic wave patterns and shortening of the sleep latency period. Non polar drug molecules dissolved in a non-aqueous sesame oil based vehicle is a significant feature in the transcranial dosage design. The study was under taken in two phases. In the Phase-I study scalp application of a single dose of 2 mg/3 ml of the oil was employed and in the Phase-II study repeat application of three doses 24 h apart were employed. Sleep latency changes were monitored with Multiple Sleep Latency Tests with 5 naps employing the standard electroencephalography, electroocculography and electromyography electrodes. Sleep onset was identified with the first epoch of any sleep stage non rapid eye movement 1, 2, 3, 4 or rapid eye movement using electroencephalography, electroocculography and electromyography criteria. In both phases of the study there was significant reduction in the sleep latencies. It was much more pronounced in the Phase-II study. None of the subjects however displayed beta activity in the electroencephalography. Sleep latency reduction following scalp application in both the phases are suggestive of transcranial migration of diazepam molecules to the receptor sites of the nerve tissue of the brain eliciting its pharmacological effect of sedation. Transcranial brain targeted dosage design is therefore feasible.

A superficial venous system of posterior neck region is very important as a possible source of complications during surgery, such as bleeding or air embolism. Despite the advances in anatomy and neurosurgery, detailed descriptions of mastoid foramen (MF) and mastoid emissary veins (MEV) are still lacking in literature. Anatomical features of the mastoid region were examined on 150 samples of the temporal bones that were selected from our large cohort. In one temporal bone we found a very large mastoid foramen with wide communication to the sigmoid sinus. We reviewed the literature and discussed the importance of variation of vascularisation in the mastoid region. Acta Medica Medianae 2014;53(4):27-29.

Cirsoid aneurysms, also known as scalp arteriovenous malformations (AVM), are rare congenital extracranial vascular anomalies that often present as an enlarging pulsatile scalp mass. A 14-yr-old male presented with a pulsatile scalp lesion that was first noticed 3 yr prior and had progressively enlarged. No history of trauma was reported. MRI demonstrated a 4 cm wide and 2 cm tall nidus and catheter angiography was performed to further define the vascular supply and drainage. The patient underwent transvenous endovascular embolization followed by surgical excision via a bicoronal incision, as shown in this operative video. Care was taken to identify, cauterize, and transect feeding vessels from the superficial temporal, supratrochlear, and supraorbital arteries circumferentially to completely devascularize and resect the galeal nidus from overlying scalp tissue and underlying pericranium. Previously unreported in the literature, transosseous emissary veins partially draining the lesion were noted on angiography and were waxed thoroughly during surgery. Six-month follow-up examination demonstrated a well-healed incision without evidence of AVM recurrence. The unique venous drainage of this cirsoid aneurysm highlights the value of diagnostic angiography to fully characterize these rare and complex vascular lesions prior to pursuing definitive treatment. IRB approval was obtained from the Ann & Robert H. Lurie Children's Hospital of Chicago Institutional Review Board (IRB #2018-1799). The IRB waives the requirement of obtaining informed consent for this study in accordance with 45 CFR 46.116(d).

Study Type – Therapy (case series) Level of Evidence 4 What’s known on the subject? and What does the study add? Venous ligation surgery has been conducted as a symptomatic treatment, but the effective rate of this surgery was insufficient. We thought that one of the reasons for the low effective rate of this surgery was insufficient for the diagnostic modality. We confirmed that 3D cavernosography was, in comparison with conventional cavernosography, higher in diagnosis precision. OBJECTIVE • To examine the feasibility of three-dimensional (3D) CT cavernosography in the diagnosis of corporal veno-occlusive dysfunction. PATIENTS AND METHODS • The subjects were 55 patients who had failed to respond to phosphodiesterase type 5 inhibitors. We performed pharmacodynamic infusion cavernosometry and cavernosography, using 60 mg papaverine hydrochloride. • Cavernosography was performed at 90 mmHg intracavernous pressure, using a multi-slice CT scan system. The 3D images were reconstructed using aquarius net station, ver.2 computer software. • For comparison with conventional cavernosography, maximum intensity projection (MIP) images were used. A flow of 20 mL/min or being more capable of maintaining 90 mmHg of intracavernous pressure indicated veno-occlusive dysfunction. RESULTS • Forty-five of the 55 patients were diagnosed with corporal veno-occlusive dysfunction. 3D-CT cavernosography revealed drainage veins in all 45 cases, including cavernous veins, dorsal veins, crural veins and other emissary veins. • Compared with 3D-CT cavernosography, observing cavernous veins and the proximal part of the deep dorsal veins using MIP imaging was especially difficult because the origins of the penile veins are often behind the pelvic bone or cavernous body. • Of the patients who seemingly had leakage via the deep dorsal vein, 80.6% did not in fact have leakage via this vein, but had other leakages. The image resolution of 3D-CT cavernosography was significantly higher than that of MIP. CONCLUSION • 3D-CT cavernosography can provide high-resolution images of venous drainage from any angle. We conclude that the images obtained by 3D-CT cavernosography are very helpful for both the diagnosis of corporal veno-occlusive dysfunction and the anatomical study of the human penile venous system.

A 59-year-old man with a 6-year history of erectile dysfunction presented to the andrology outpatient clinic. Multimodality assessment with ultrasound, MRI venography and fluoroscopic venography demonstrated an aberrant emissary vein arising from the corporal bodies causing venogenic erectile dysfunction. Selective coil embolisation of the collateral vein resulted in an almost immediate and sustained improvement in his erections.

Knowledge of penile embryology and anatomy is essential to any pediatric urologist in order to fully understand and treat congenital anomalies. Sex differentiation of the external genitalia occurs between the 7thand 17thweeks of gestation. The Y chromosome initiates male differentiation through the SRY gene, which triggers testicular development. Under the influence of androgens produced by the testes, external genitalia then develop into the penis and scrotum. Dorsal nerves supply penile skin sensation and lie within Buck's fascia. These nerves are notably absent at the 12 o'clock position. Perineal nerves supply skin sensation to the ventral shaft skin and frenulum. Cavernosal nerves lie within the corpora cavernosa and are responsible for sexual function. Paired cavernosal, dorsal, and bulbourethral arteries have extensive anastomotic connections. During erection, the cavernosal artery causes engorgement of the cavernosa, while the deep dorsal artery leads to glans enlargement. The majority of venous drainage occurs through a single, deep dorsal vein into which multiple emissary veins from the corpora and circumflex veins from the spongiosum drain. The corpora cavernosa and spongiosum are all made of spongy erectile tissue. Buck's fascia circumferentially envelops all three structures, splitting into two leaves ventrally at the spongiosum. The male urethra is composed of six parts: bladder neck, prostatic, membranous, bulbous, penile, and fossa navicularis. The urethra receives its blood supply from both proximal and distal directions.

The suboccipital lateral or retrosigmoid approach is the main neurosurgical approach to the cerebellopontine angle (CPA). It is mainly used in the treatment of CPA tumors and vascular decompression of cranial nerves. A prospective study using navigation registered with anatomical landmarks in order to identify the transverse and sigmoid sinuses junction (TSSJ) was carried out in a series of 30 retrosigmoid craniotomies. The goal of this study was to determine the accuracy of this navigation technique and to establish the relationship between the location of the asterion and the TSSJ. From March through November 2008, 30 patients underwent a retrosigmoid craniotomy for removal of CPA tumors or for surgical treatment of neurovascular syndromes. Magnetic resonance imaging (MRI) T1 sequences with gadolinium (FSPGR with FatSst, 1.5 T GE® Signa) and frameless navigation (Vector vision®, Brainlab®) were used for surgical planning. Registration was performed using six anatomical landmarks. The position of the TSSJ indicated by navigation was the landmark to guide the craniotomy. The location of the asterion was compared with the position of the TSSJ. After craniotomy, the real TSSJ position was compared with the virtual position, as demonstrated by navigation. There were 19 cases of vestibular schwannomas, 5 petroclival meningiomas, 3 trigeminal neuralgias, 1 angioblastoma, 1 epidermoid cyst and 1 hemifacial spasm. In all cases, navigation enabled the location of the TSSJ and the emissary vein, with an accuracy flaw below 2 mm. The asterion was located directly over the TSSJ in only seven cases. One patient had a laceration of the sigmoid sinus during the craniotomy. Navigation using anatomical landmarks for registration is a reliable method in the localization of the TSSJ for retrosigmoid craniotomies and thereby avoiding unnecessary sinus exposure. In addition, the method proved to be fast and accurate. The asterion was found to be a less accurate landmark for the localization of the TSSJ using navigation.

UMMARY The deep dural sinuses and the veins in the midline in 52 brains of children dying with myelomeningocele were examined. All of these vessels were very abnormal in each case. The abnormal features are described and discussed. When the cerebrospinal fluid pressure is elevated, the transverse sinuses seem to be compressed in children with myelomeningocele. The blood therefore is drained through the emissary veins and then by the skull veins. This explains why the skull veins are engorged with blood in these children in intracranial hypertension. The existence of a wide common facial vein is as easily understood. RESUME Les sinus duraux et les veines du milieu du cerveau dans le myelomeningocele Les sinus duraux profonds et les veines de la ligne mediane de 52 cervaux d'enfants morts avec un myelomeningocele ont ete examines. Tous les vaisseaux etaient tres anormaux dans tous les cas. Les anomalies sont decrites et discutees. Quand la pression du LCR est augmentee, les sinus transverses semblent comprimes chez I'enfant avec myelomeningocele. Le sang est alors draine par les veines emissaires puis les veines du crCne. Ceci explique que les veines du crCne soient remplies de sang chez ces enfants avec hypertension intra-cranienne. L'existence d'une veine faciale commune large est ainsi aisement comprise. ZUSAMMENFASSUNG Die Sinus der Dura und die Venen in der Mittellinie des Gehirns bei der Myelomeningocele Die tiefen Sinus der Dura und die Venen in der Mittellinie des Gehirns wurden bei 52 Kindern untersucht, die an einer Myelomeningocele gestorben waren. Alle diese Gefase waren in jedem Falle sehr abnorm. Die abnormen Erscheinungen werden beschrieben und diskutiert. Wenn der Druck des Liquors erhoht ist, scheinen die quer verlaufenden Sinus bei Kindern mit Myelomeningocele komprimiert zu werden. Das Blut flieBt deswegen uber die emissaren Venen und dann uber die SchUdelvenen ab. So erklart sich, warum die Schadel-venen bei diesen Kindern mit intracranieller Hypertonic mit Blut vollgestaut sind. Auch die Existenz einer erweiterten Vena facialis communis ist so leicht zu verstehen.

With the surgical removal of temporal paraganglioma, possible changes of the cerebral blood pathways of the Circle of Willis should be considered. If the cerebral blood drains dominates unilaterally and the pathway of drainage over the Bulbus venae jugularis is inadequate due to vessel malformation or variations or by intraluminal tumor growth, as for instance of temporal paragangliomas, collateral emissary vessels can take over this function by an extraordinary large lumen extension. Ignorance of such a characteristic venous drainage can lead to hemorrhagic apoplexia when such originally redundant veins are sacrificed. A presurgical angiography is, therefore, indicated. In case of vessel malformations or variations the use of computer-assisted surgery could be helpful to preserve such native emissary veins at the bony skull base, such as the condylar emissary vein in the case of a transcondylar infralabyrinthine approach.

A brief general theory is proposed linking the transcephalic DC potential, which is recorded on the midline surface of the head over the frontal and occipital emissary veins, with a certain functional organization of the brain. From this it is proposed that interoceptive or protopathic afferents—carotid sinus, carotid body, vestibular, and visceral—should produce a positive frontal deflection, while exteroceptive or epicritic afferents—tactile, auditory, proprioceptive, gustatory, visual, and olfactory—should produce a negative frontal DC shift. It is proposed that hunger promotes a negative frontal base line, satiety a positive one, and anxiety increases the base-line variance of a group. A relationship is proposed between frontal negativity and body metabolic peaks. It is proposed that a noxious exteroceptive stimulus produces a positive frontal shift, despite its cortical projection. The hypotheses were tested using normal adult male Ss and good agreement between results and predictions was found.

Homozygous mutations in the fibroblast growth factor 3 (FGF3) gene have recently been discovered in an autosomal recessive form of syndromic deafness characterized by complete labyrinthine aplasia (Michel aplasia), microtia, and microdontia (OMIM 610706 - LAMM). In order to better characterize the phenotypic spectrum associated with FGF3 mutations, we sequenced the FGF3 gene in 10 unrelated families in which probands had congenital deafness associated with various inner ear anomalies, including Michel aplasia, with or without tooth or external ear anomalies. FGF3 sequence changes were not found in eight unrelated probands with isolated inner ear anomalies or with a cochlear malformation along with auricle and tooth anomalies. We identified two new homozygous FGF3 mutations, p.Leu6Pro (c.17T > C) and p. Ile85MetfsX15 (c.254delT), in four subjects from two unrelated families with LAMM. The p.Leu6Pro mutation occurred within the signal site of FGF3 and is predicted to impair its secretion. The c.254delT mutation results in truncation of FGF3. Both mutations completely co-segregated with the phenotype, and heterozygotes did not have any of the phenotypic findings of LAMM. Some affected children had large skin tags on the upper side of the auricles, which is a distinctive clinical component of the syndrome. Enlarged collateral emissary veins associated with stenosis of the jugular foramen were noted on computerized tomographies of most affected subjects with FGF3 mutations. However, similar venous anomalies were also detected in persons with non-syndromic Michel aplasia, suggesting that a direct causative role of impaired FGF3 signaling is unlikely.

CHARGE syndrome was first described by Pagon, and was named for its six major clinical features, which are; coloboma of the eye, heart defects, atresia of the choanae, retarded growth and developmental anomalies, which include CNS anomalies, genital hypoplasia and/or urinary tract anomalies, and ear anomalies and/or hearing loss. The authors experienced a case of CHARGE syndrome that displayed bilateral jugular foramen atresia and a collateral emissary vein. In addition, the authors reviewed the literatures pertaining to CHARGE syndrome.

This paper discusses how the evolving hominid architecture of the arteriovenous system through the cranial base diverted foreseeable pathology in the human brain. Bipedal upright posture was an early adaptation in mosaic morphological pattern changes in hominid evolution; a key feature, the ability of blood to flow either to vertebral or internal jugular venous systems. Encephalization punctuated hominid evolution, its vulnerable feature, a lower threshold for thermal damage. Comparative analysis of ape and human skulls show “fingerprint” structures, revealing big changes in pattern complexity of the cranial vascular tree. Clues to structural/functional changes span data for apes, humans, and hominid fossils. Here, the increasing vascular network, Australopithecus to Homo sapiens, necessitated changes in the blood flow patterns. The transverse-sigmoid (T/S) and occipital-marginal (O/M) venous networks accommodated hydrostatic changes of blood flow, regulating temperature uniquely: the O/M system enlarged, allowing blood to flow straight down into the vertebral plexus without cooling, and added a vast network of emissary/diploic veins, acting as a brain cooling “radiator.” This O/M system was fixed in the Australopithecus robustus lineage, p = 0.000001; high frequencies of emissary foramen were selected for over time. Ontologically, the human neonatal O/M system is fully developed; emissary/diploic veins are established by age 5, setting conditions for selective brain cooling. The Radiator Theory is the evolution of the functionally efficient brain cooling system, fixed in the A. robustus lineage, tying hydrostatic consequences of bipedalism with release of a “thermal constraint” on the encephalizing brain, and reflected in our own ontogeny.

Sinus pericranii (SP) is a rare, usually asymptomatic condition characterized by a large communication between the intra- and the extracranial venous drainage pathways in which blood may circulate bidirectionally through dilated veins of the skull. We describe our diagnostic and therapeutic experience with SP, with a special focus on the vascular analysis of digital subtraction angiography (DSA). DSA images of 15 patients were evaluated with regard to the delay in opacification of the scalp vessels, the absence or distortion of the superficial cortical veins in the vicinity of the SP, the drainage patterns of the superior sagittal sinus, and the degree of maturation of the venous outlets of the brain. SP were classified either as “dominant”, if the main stream of contrast flow used the SP to drain the brain bypassing usual venous outlets, or as “accessory”, if only a small part of the venous outflow occurred through the extradiploic vessels. All patients presented with a nonpulsatile, soft-tissue mass. The lesion was on the midline in 14 of 15 patients, frontal in 12 patients, and parietal in 2 patients. In 13 patients, associated intracranial venous anomalies were present, eight of which were developmental venous anomalies. Seven patients had a dominant SP, and eight an accessory SP. SP can be considered the cutaneous sign of an underlying venous anomaly. If treatment is contemplated, analysis of the drainage pattern of the SP has to be performed. Treatment should be avoided in dominant SP or if its accessory role constitutes the only collateral pathway of an underlying venous anomaly.

AIm: The knowledge of the vasculature around the paracondylar region is important in neurosurgical procedures such as the paracondylar and lateral supracondylar approaches. The objectives of the present study were to determine the prevalence of paracondylar emissary foramina in the adult skull bases and to study the morphology of condylar canals and hypoglossal canals. Ma terIal and Methods: The present study included 48 adult human skulls that were obtained from the gross anatomy laboratory of our institution. The paracondylar region was macroscopically observed for the variant foramina, canals and grooves. Results: It was observed that the paracondylar emissary foramen was present in 16 skulls (33.3%). The foramen was found bilaterally in 7 skulls (14.6%) and unilaterally in 9 skulls (18.7%). The hypoglossal canal was single in 35 (72.9%) skulls, double in 11 skulls (22.9%), and triple in 2 skulls (4.2%). The paracondylar process (2.1%) and the paracondylar groove (2.1%) were seen in 1 skull each. The posterior condylar canal was found to be patent in 19 (39.6%) skulls. ConclusIon: The present study observed that, the paracondylar emissary vein is not rare in occurrence as it is observed in 33.3% of cases. The identification of the paracondylar emissary veins and accessory vessels is important to avoid dangerous bleeding during the surgery. The morphological knowledge of the foramina around the paracondylar region is enlightening to the chiropractors, neurosurgeons and radiologists.

Background: The aim of the study was to evaluate the prevalence and morphometric features of mastoid emissary vein (MEV) on multidetector computed tomography (MDCT) scans, emphasize its clinical significance and review its surgical implications. Materials and methods: Cranial and temporal bone MDCTs of 248 patients (496 sides) were analysed by 2 radiologists. Mastoid foramen (MF) was defined on the 3 dimensional volume rendered (3DVR) images. The MF and mastoid emissary canal (MEC) were investigated in axial thin slices and the diameters of the largest MF and MEC were measured. Mean diameters of MF and MEC were determined. The number of the mastoid foramina was noted. Differences in MF prevalence by sex and side were evaluated. Results: The overall prevalence of MEC was 92.3%. It was observed in 91.5% of women and 93.3% of men. MEC was present on the right side in 84.7% and on the left side in 82.3% of temporal bones. The mean diameter of MF was 1.92 +/- +/- 1.02 mm on the right and 1.84 +/- 0.98 mm on the left. In both sides the number of the MF's changed from absent to triple. The mean diameter of MEC was 1.58 +/- 0.86 mm on the right and 1.48 +/- 0.79 mm on the left side. The mean diameter of MEC was significantly larger in men. No significant correlation was detected between age and the MEC diameter. Conclusions: The preoperative detection of mastoid emissary veins is necessary. The radiologists should be familiar with their clinical significance and variant appearances and report them accurately. Knowledge of their morphology and surgical implications by the surgeons will make them aware to avoid unexpected and fatal complications while operating in the suboccipital and mastoid area. MDCT is a reliable diagnostic tool for imaging the MEC and MF.

Patients with multisutural craniosynostosis can develop anomalous venous connections between the intracranial sinuses and cutaneous venous system through enlarged emissary veins. Cranial vault remodeling in this subset of patients carries the risk of massive intraoperative blood loss and/or occlusion of collateral draining veins leading to intracranial venous hypertension and raised intracranial pressure, increasing the morbidity of cranial expansion. The authors report the use of spring-mediated expansion as a technique for cranial reconstruction in which the collateral intracranial venous drainage system can be preserved. A patient with bilateral lambdoid, sagittal, and unicoronal synostosis presented for cranial reconstruction. A tracheostomy and ventriculoperitoneal shunt were placed prior to intervention. At the time of reconstruction, a Luckenschadel skull abnormality and Chiari malformation Type I were present. A preoperative CT venogram demonstrated large collateral superficial occipital veins, small bilateral internal jugular veins, and hypoplastic jugular foramina. Collateral flow from the transverse and sigmoid sinuses through large occipital emissary veins was seen. Spring-mediated cranial vault expansion was performed with care to preserve the large collateral veins at the occipital midline. Four springs were placed at each lambdoid and the posterior and anterior sagittal sutures following 1-cm strip suturectomies. Removal of the springs was performed 2 months postoperatively. Cranial vault expansion was performed without disturbing the aberrant intracranial/extracranial venous collateral system. Estimated blood loss was 150 ml. A CT scan obtained 3 months postoperatively showed resolution of the Luckenschadel deformity and a 40% volumetric increase in the skull compared with the preoperative CT. Patients with anomalous venous drainage patterns and multisutural synostosis can undergo spring-mediated cranial vault expansion while preserving the major emissary veins draining the intracranial sinuses. Risks of blood loss, intracranial venous hypertension, and increased intracranial pressure may be decreased compared with traditional techniques of repair.

Background Right adrenal vein (RAV) catheterization can be a very challenging step in adrenal venous sampling (AVS). Visualization of the inferior emissary vein (IEV) may be an indication of successful RAV catheterization. Purpose To compare the rate of successful RAV sampling in the presence of the IEV. Material and Methods Retrospective review of all consecutive patients with PA who underwent AVS between April 2009 and April 2012 was performed. A total of 30 patients were identified. Procedural images, cortisol, and aldosterone values obtained from sampling of the RAV and inferior vena cava (IVC) were reviewed. Cortisol measurements obtained from RAV samples were divided by measurements from the infra-renal IVC blood samples in order to calculate the selectivity index (SI). An SI >3 was considered indicative of technically successful RAV sampling. Results RAV sampling was considered technically successful in 29 out of 30 cases (97%). In cases of successful RAV sampling (29 patients), the IEV was identified in 25 patients (86%). The IEV was visualized in isolation in 16 patients (64%), and in conjunction with visualization of the RAV or right adrenal gland stain in nine patients (36%). The IEV was not visualized in the one case of unsuccessful RAV sampling. Visualizing the IEV had a sensitivity of 86.2% for successful RAV sampling. Conclusion The IEV may serve as a reliable landmark for the RAV during RAV sampling.

A 36-year-old male who had history of hearing loss since childhood presented with a chronically discharging right ear. HRCT temporal bones revealed non-dependent opacification in the epiand meso-tympanum with medially displaced head of malleus, erosion of incus and the tegmen tympani suspicious for an attic cholesteatoma. In addition, there was a serpiginous structure seen extending across the posterior aspect of the mastoid temporal bone which was thought to represent a trans-mastoid emissary vein. MRI subsequently performed showed both the lesions (in the middle ear cavity and the serpiginous structure in the mastoid) were hyperintense on Propeller DW (b value 1000 sec/mm) sequence suggesting 2 cholesteatomas. The serpiginous structure in the mastoid did not show post contrast enhancement thus excluding a vascular lesion. A canal wall down mastoidectomy was done which confirmed both the findings.

The models generally used to explain the practice of cranial osteopathy have not been supported by reliable research. This paper reviews and explores the relevant physiology and finds much to advance knowledge in this field. Arterial vasomotor waves have a frequency similar to reports of cranial rhythmic impulses; these are controlled by the sympathetic nervous system. Thermoregulation can reverse venous flow through emissary veins of the skull. Cerebrospinal fluid is circulated by arterial pulsations and is partially drained via the cribiform plate into nasal and cervical lymphatics. A model for the practice of cranial osteopathy based on well-researched physiology is proposed, and some clinical implications outlined. Some reasons for poor interobserver agreement in palpatory studies are discussed. This paper should provide a basis for informed research in this subject in the future.

This is the first of two articles designed to provide user-friendly schematics of the adult dural vascular anatomy. It describes the intrinsic meningeal arteries and veins of the skull base/cranial vault and the dural partitions (the tentorium, falx cerebelli, and falx cerebri). The discussion of this anatomy is supplemented by illustrative pathologic insights. The second article focuses on the dural sinuses and their remaining tributaries from the brain, diploë, and emissary veins from the extracranial soft tissues. This information will assist in interpreting neuroimaging studies, communications with clinicians, and teaching of this difficult subject.

Background: The hypoglossal canal is one among the permanent components of occipital bone of both human being and animal skull, which transmits the twelfth cranial nerve, meningeal branch of ascending pharyngeal artery and emissary veins. This is commonly known as anterior condylar canal. In some cases, this canal is divided by a bony spicule leading to a variant known as double hypoglossal canal. Such partition of hypoglossal canal predisposes the roots of twelfth cranial nerve to entrapment in the occipital bone during ossification which subsequently may leads to an alteration in the tongue movement as well as speech. The objectives of the present study were to obtain the incidence of the variant of double hypoglossal canal in north Indian population especially in Bihar and compare the incidence of such type of variation in skull of different parts of our country as well as various races of the world.Methods: The present study was carried out on 110 undamaged dry adult human crania of unknown age and sex for any variations in the hypoglossal canal or incidence of double hypoglossal canal.Results: We observed 15 cases (13.63%) of double hypoglossal canal in which 8 (7.27%) specimens had unilateral while 7 (6.36%) specimens had bilateral double hypoglossal canal. Double hypoglossal canal was more common in right side. In 5 cases (4.54%) unilateral bony spicules were seen.Conclusions: The study about the hypoglossal canal and its different variation is very important to clinicians, anatomist, forensic experts as well as anthropologists too. The knowledge about the different dimensions of hypoglossal canal is also very essential for neurosurgeons and radiologist for the planning of the surgeries around the posterior cranial fossa for tumors like schwannoma of hypoglossal nerve and treatment of sleep apnea syndrome. Hence the detailed morphometric study of hypoglossal canal will be helpful for the planning of surgical intervention around the base of skull becomes easier and safer.

Introduction: The foramen Vesalius is located within bony plate between the foramen ovale and the foramen rotundum in the floor of middle cranial fossa. This foramen allows passage of emissary veins which communicate cavernous sinus and pterygoid plexus of veins. AIM: To study the morphological and morphometric variations of foramen Vesalius in dry adult human skulls. Materials and Methods: One hundred and fifty dry adult human skulls were studied for variations in size, shape, presence/absence and any duplication/multiplication of the foramen Vesalius. After collecting data, appropriate statistical analysis was done. Results: The mean maximum dimension of foramen Vesalius was 0.98±0.67 mm on right side and 1.12±0.73 mm on left side. Foramen Vesalius was present in 90 (60%) skulls out of 150 observed. The incidence was 41(27.33%) on right side and 49 (32.67%) on left side. Foramen Vesalius was present unilaterally in 32 (35.56%) and bilaterally in 29 (32.23%) out of 90 skulls. Duplication of this foramen was observed in two skulls (one right side and one on left side). Foramen Vesalius was round in 72%, oval in 24% and irregular in 4% of total foramina present. Conclusion: Foramen Vesalius was present in 60% of total skulls studied. The foramen showed variations in incidence and shapes, while there was no statistically significant difference in the maximum dimension between foramen Vesalius on right and left side. There could be some developmental reasons to explain these variations. The findings of this study could be important to anatomists and also equally essential for clinicians who approach middle cranial cavity for various procedures.

The sphenoidal emissary foramen (SEF) is an inconsistent foramen located in the middle cranial fossa. The SEF may transmit a sphenoidal emissary vein (of Vesalius), dural venous sinus, nervolulus sphenoidalis lateralis, or an accessory middle meningeal artery. Prior reports have noted SEF to exist unilaterally and bilaterally. Duplication of the SEF has also been documented to occur unilaterally. The case reported herein documents a bilateral duplication of the SEF. Because the SEF are occasionally cannulated by mistake in procedures which attempt to access the middle cranial fossa via the foramen ovale, knowledge of the bilateral duplication of the SEF is important for neurosurgeons and radiologists.

In order to investigate the diagnostic properties of MRI of the brain and spine in achondroplastic children with regard to decompressive surgery, 25 patients were examined by conventional morphological and by "functional" imaging of CSF flow and magnetic resonance angiography (MRA) of the veins and sinuses at the cranial base following a special protocol. The results were compared to those from age-matched controls and were correlated with each other and retrospectively with the neurological findings. Measurements of distances and angulations at the cranio-cervical junction (CCJ) from MR scans showed similar values to those from conventional radiographs and CTs and thus can be used without correction for spatial distorsion. Signs of cervical medullary compression, myelomalacia and intramedullary cyst formation were found in six, seven and three children respectively. These alterations correlated significantly with each other (P0.05). Semiquantitative evaluation of CSF flow demonstrated interruption of CSF pathways at the CCJ, which correlated with CCJ narrowing (P0.05). MRA showed a significant narrowing of the jugular foramina with a variable compensatory enlargement of the emissary veins and a significant reduction of the total outflow area (P0.01). There were no significant correlations between these MR changes and neurological deficits.Due to this unexpectedly poor correlation between magnetic resonance and clinical findings in achondroplastic children, the present role of magnetic resonance in the clinical setting is limited to the demonstration of spinal cord compression in individual cases. In three of our patients with prominent neurological abnormalities, the severe changes demonstrated by magnetic resonance imaging strongly supported the indication for surgical decompression.

Two patients presented with hypoglossal neurinoma extending both intra- and extracranially. A 63-year-old male presented with right trigeminal neuralgia and hypoglossal nerve paresis. The intracranial part of the tumor was removed totally via a suboccipital craniectomy. Over-coagulation of the venous collaterals, particularly the emissary veins, resulted in dural venous sinus thrombosis and cerebellar infarction. Unfortunately this patient died. A 48-year-old male presented with pareses of the VII, IX, X, XI, and XII cranial nerves and cerebellar sign. The tumor extended both extra- and intracranially, and was completely removed by opening the hypoglossal canal and the jugular foramen without over-coagulation of the venous collaterals. Preservation of the venous collaterals is very important for the prevention of postoperative venous complications.

Original data about venous channels in South African Plio-Pleistocene hominids are discussed. To assess possible changes in blood volume flow of fossil hominids, we test whether dimensions of three extracranial venous foramina were different between Australopithecus africanus and Australopithecus (Paranthropus) robustus Moreover, providing further data about the small sample of South African Plio-Pleistocene hominids, we also attempt to re-analyse the incidence of divided hypoglossal canals and four emissary foramina in a very large sample of extant African apes representing all ages, species and subspecies, in A. africanus and in “robust australopithecines”. Up to now, only very poor data on extracranial dimensions of venous foramina were available for fossil hominids. However, this topic provides interesting information about the modifications of volume flow during human evolution. Assuming that in fossil hominids, as in humans, dimensions of condylar and mastoid foramina, as well as those of jugular foramina, depended on volume flow through them, we conclude, first, that volume flow through internal jugular veins was comparable in South African australopithecines, extant chimpanzees and humans, and second, that, in comparison with the extant less-encephalized chimpanzees (presumably reflecting the ancestral condition), volume flow was higher through condylar veins in A. (P.) robustus This increase was responsible for a significantly greater amount of blood drainage from the brain (and consequently an increased arterial blood supply). We support the view that encephalization was the prevailing functional explanation for volume flow increase through condylar veins in A. (P.) robustus in comparison with its ancestor with its presumably more ape-like degree of encephalization. Considering the incidence of emissary canals and foramina, significant differences between A. africanus “robust australopithecines” and all the extant African ape species, were tested statistically. Concerning the condylar canal, we did not find differences between “robust australopithecines” and extant African apes. Concerning the incidence of divided hypoglossal canals, mastoid canals, parietal and occipital foramina, no difference was found between extant African apes, A. africanus and “robust australopithecines”. High frequencies of either condylar or mastoid canals cannot be regarded as a “pongid condition”. Moreover, we did not find convincing data to support the hypothesis that mastoid emissary veins (partly representing a putative “radiator” for cooling the brain) were selected in A. africanus in comparison with “robust australopithecines”.

We report the radiological findings of severe bilateral jugular foraminal stenosis along with anomalous basicranial venous drainage in a child with a history of complex nonsyndromic craniosynostosis. CT with 3D reconstructions and MR venography revealed that the lateral sinuses were draining transosseously through several markedly enlarged emissary veins. The main route of transverse and sigmoid sinus drainage was through large mastoid emissaries to the deep cervical veins. There was additional drainage of these mastoid emissaries into the vertebral and paravertebral plexuses as well as into venous collaterals which subsequently reconstituted the internal jugular veins. Basicranial venous anomalies are common among children with complex craniosynostosis, and although they may not resemble intracranial vascular outflow deficiencies, they can pose significant surgical risks. This case emphasizes the need for proper clinical assessment and documentation of anomalous basicranial venous anatomy to facilitate management of complex craniosynostosis patients.

Posterior fossa emissary veins are valveless veins that pass through cranial apertures. They participate in extracranial venous drainage of the posterior fossa dural sinuses. The mastoid emissary vein, condylar veins, occipital emissary vein, and petrosquamosal sinus are the major posterior fossa emissary veins. We believe that posterior fossa emissary veins can be detected by radiologists before surgery with a thorough understanding of their anatomy. Describing them using temporal bone computed tomography (CT), CT angiography, and cerebral magnetic resonance (MR) venography examinations results in more detailed and accurate preoperative radiological interpretation and has clinical importance. This pictorial essay reviews the anatomy of the major and clinically relevant posterior fossa emissary veins using high-resolution CT, CT angiography, and MR venography images and discusses the clinical importance of reporting these vascular variants.

For more than a century, available data concerning collateral venous outflow from the brain have received insufficient attention, as existing theories did not assign practical importance to them. Ideas concerning arterial blood supply and circulation of cerebrospinal fluid were considered more relevant. But available data afford a schematic model of cerebral venous outflow that does have important pathophysiological consequences. Principal outflow through the internal jugular veins can be substituted completely by the large vertebral plexuses, through communications at the cranial base. Emissary veins of the skull vault are small and few in number. Outflow from the deep venous system through the great vein of Galen can be substituted by choroidal, thalamic and striate anastomoses toward the basal vein. So-called intracerebral venous anastomoses through the centrum semiovale towards the convexity are nonexistent or negligible. Instead, a venous watershed exists separating paraventricular white matter from a layer of subcortical white matter. In most infants, the cavernous sinus is not yet connected to the cerebral veins. Once such communications have been formed, important collateral pathways exist through basal and Sylvian veins via the cavernous sinus to the pterygoid plexuses. Simultaneous hindrance of principal and collateral venous outflow will lead to elevated venous pressure and eventual insufficiency of cerebral blood flow (CBF). This will cause increased intracranial pressure, and ventricular enlargement due to periventricular atrophy. The slow phase of the two-compartment model of CBF coincides with the paraventricular white matter area of the deep venous system. In the neonate CBF was found to be still very low, and in the two compartments CBF increases at a different rate to a maximum in childhood. In hydrocephalus, measurement of CBF in the slow deep compartment, rather than the fast cortical one, will be most informative.

Objective : Small venous air emboli probably occur frequently. Out purpose was to describe the locations of small venous air emboli detected on CT scans of the head and neck and their clinical presentations. Materials and Methods : The head CT scans of 17 patients and neck CT scans of 10 patients with suspected venous air emboli were reviewed and the locations of the gas collections were recorded. The charts of these patients were reviewed to identify possible sources of these gas collections and any symptoms they may have produced. Results : The most likely source of these gas collections was venous air emboli. The neck CT scans demonstrated gas in the inferior internal jugular vein, subclavian vein, and small anterior neck veins. The head CT scans demonstrated gas in the cavernous sinus, the frontal and temporal scalp, the infratemporal fossa, the carotid canal, the straight sinus, the superior ophthalmic vein, the superior sagittal sinus, extracranially in the region of the foramen magnum, and in a canal in the skull base for an emissary vein or the inferior petrosal sinus. Most of the intravenous lines were placed within 6 h of the scans demonstrating gas. The gas collections did not produce symptoms. Conclusion : Asymptomatic venous air emboli can be identified in several locations in the head and neck. The time between manipulation of intravenous lines and the scan, the position of the patient, and the anatomy of the patient probably all affect the likelihood of identifying venous air emboli on CT scans.

Delayed supratentorial intracerebral hematoma after posterior fossa surgery is uncommon. Only few cases have been reported in the past. The cause has been attributed to sitting position leading to changes in intracranial arterial and venous pressures. We report two cases of delayed intracerebral hematoma following posterior fossa surgery, none of which were operated in sitting position. MR venogram done in one patient showed venous sinus thrombosis. Intracererbal hematoma following infratentorial surgery is uncommon and is possibly due to venous sinus thrombosis leading to venous hypertension. Control of bleeding from venous sinuses due to avulsion of emissary veins during craniotomy/craniectomy possibly induces sinus thrombosis that may propagate antegrade or retrograde, leading to venous hypertension and parenchymal bleed.

Enlarged parietal foramina (>5 mm) is an extremely rare developmental defect of the parietal bone, which is distinguished from the normal small parietal foramina, as genes associated with this entity have been identified, suggesting that it is hereditary in nature. We describe a dry skull of a 35-year-old female, with enlarged parietal foramina symmetrically situated bilaterally, oval in shape, measuring 4.5 × 9.3 mm (right) and 4.9 × 9.2 mm (left) in size. The foramina coexisted with multiple Wormian bones in several sites of the skull. On the inner parietal bone surface, the anterior, posterior and lateral foramina’s rims carried grooves, which were continuous with the middle meningeal vessels’ branches, indicating that a rich vascular network existed around the foramina. These vascular grooves also notched the external table at the margin of the foramina, which suggests a potential communication between the meningeal and the scalp vessels. In addition, this vascular variation should be taken into consideration when performing surgical interventions in the area, because the large vascular supply to the foramina is a possible source of extensive bleeding. Moreover, the interaction of intracranial and extracranial veins and the fact that the blood flows in them in both directions, as they are valveless, could represent a possible pathway for infections to spread in the cranial cavity.

The emissary veins are residual connections between intracranial venous sinuses and their extracranial drainage, which if not diagnosed preoperatively could be a cause of severe hemorrhage at the time of surgery which may be life threatening. The petrosquamosal emissary sinus (PSS) which is a rare embryonic emissary vein along the petrosquamosal fissure of the temporal bone connects dural sinuses with external jugular venous system. The PSS has been known to regress during fetal and early postnatal life. The imaging diagnosis of the PSS has been rarely reported in humans. We report the presence of the PSS with laterally located sigmoid sinus in patient with chronic otitis media. Our hope is that this report will be useful to the otologist during surgery.

The posterior condylar canals (PCCs) and posterior condylar emissary veins (PCEVs) are potential anatomical landmarks for surgical approaches through the lateral foramen magnum. We conducted computed tomography (CT) and microsurgical investigation of how PCCs and PCEVs can aid in planning and performing these approaches. We analyzed the microanatomy of PCCs and PCEVs using cadaveric specimens, dry skulls, and CT images. The recognition frequency and geometry of PCCs and PCEVs and their relationships with surrounding structures were evaluated. PCCs were identified in 36 of 50 sides in dry bones and 82 of 100 sides by CT. PCCs had a 3.5-mm mean diameter and a 6.8-mm mean canal length. We classified their courses into four types according to intracranial openings: the sigmoid sinus (SS) type, the jugular bulb (JB) type, the occipital sinus type, and the anterior condylar emissary vein type. In most cases, PCEV originated near the boundary between the SS and JB. PCCs and PCEVs can be useful anatomical landmarks to differentiate the transcondylar fossa approach from the transcondylar approach, thus preventing unnecessary injury of the atlantooccipital joint. They can also be used as landmarks when the jugular foramen (JF) and hypoglossal canal (HGC) are being exposed. The area anterior to the brain stem and the medial part of HGC can be accessed by removal of the lateral foramen magnum medial to PCC. JF and the lateral part of HGC can be accessed by removal of the skull base lateral to PCC without damaging the lateral rim of the foramen magnum.

An 18 months-old male infant presented with an irregular left-sided scalp swelling of 4-month duration (Figs. 58.1 and 58.2). The swelling was fluctuant and opaque. He had a history of severe rhinitis, fever and nasal obstruction prior to the development of the swelling. He was otherwise healthy, with no history of trauma, and no focal neurological deficits. There was no break in the skin over the involved area.