Mount Fuji Research Articles

A Hump-Backed Trend in Bacterial Diversity with Elevation on Mount Fuji, Japan

Little is known of how bacterial diversity in soils varies with elevation. One previous study found a decline with elevation, whereas another found no trend. We chose Mount Fuji of Japan as a geologically and topographically simple mountain system. Samples were taken at elevational intervals, between the base of the mountain at 1,000 m and its summit at 3,700 m. Polymerase chain reaction-amplified soil DNA for the bacterial 16S gene targeting V1-V3 region was pyrosequenced using the 454 Roche machine, and taxonomically classified with reference to a bioinformatic database. There was a significant "peak" in total bacterial diversity at around 2,500 m above the tree line with a decline towards the highest elevations around 3,700 m near the summit. Individual bacterial phyla show distinct trends-increase, decrease, or a mid-elevational "bulge" in diversity. Bacterial diversity does not parallel woody plant or herbaceous plant diversity. We suggest that beyond the tree and vegetation line, the more extreme temperature fluctuations, stronger UV, lack of nutrients, and more frequent disturbance of the loose substrate of these slopes allows less competition and greater bacterial species diversity due to "lottery" recruitment. However, at the highest elevations, the physiological challenges are so extreme that fewer bacterial species are capable of surviving.

High-resolution reconstruction of the Hoei eruption (AD 1707) of Fuji volcano, Japan

The Hoei eruption of Mount Fuji in 1707 caused the worst ashfall disaster in Japanese history. Despite the availability of numerous historical documents describing the eruption, the detailed eruption sequence has not been verified because the correlation between these descriptions and geological sequences remains unclear. In this study, we reconstruct the sequential change in the column height using newly established stratigraphy and a detailed timeline obtained from historical documents. The eruptive deposit was subdivided into 17 units on the basis of their facies, with the mass of each unit established using isopach maps. The eruption column height is a function of the magma discharge rate; hence, the column height of each unit was estimated from its erupted mass and duration, which were inferred from the historical documents. The correlation of each unit with the actual time was based on the tephra color and grain size, an unconformity caused by rainfall, and ashfall distribution. While reconstructing the unit boundaries, we found that not all of them represented a hiatus or relenting phase of ashfall. We detected only six obvious quiet intervals from the historical documents. Therefore, many of the unit boundaries may represent a hiatus or relenting phase that was too subtle to have been recorded in the historical documents. We define an eruptive pulse as a period of continuous ashfall followed by an obvious quiet interval. We divided the 17 units of the Hoei eruption into 6 pulses, and into 3 stages on the basis of the patterns of the eruptive pulses. The characteristics of the three stages are described as follows. Stage 1 had two energetic eruptive pulses (pulses 1 and 2; at least 20 km high column), each showing an intense initial outburst, followed by a decrease in intensity. The eruption sequence indicates ruptures of highly overpressured dacite and andesite magma chambers. The initial silicic eruption was followed by basaltic magma withdrawal from a deep and voluminous magma chamber. Stage II consisted of discrete subplinian pulses of relatively degassed basaltic magma. Although the eruption rate throughout the stage decreased, the magma supply from depth appears to have been sustained because extensive intrusion near the surface created the Mt. Hoei cryptodome near the vent. Stage III was principally characterized by sustained column activity without a clear repose time. During this stage, the column height appears to have been more than 13 km, and we recognized at least two distinct periods of increased activity in which the column height is presumed to have exceeded 16 km. The Cu-rich vesicular scoria and continuous eruption in stage III indicate a stable supply of volatile-rich magma from depth. No significant decay was observed in the magma discharge rate; hence, the eruption could have been halted by a sudden process such as conduit collapse, rather than decompression of the magma chamber.

Influence of the March 11, 2011 M w 9.0 Tohoku-oki earthquake on regional volcanic activities

Two days after the March 11, 2011, M w 9.0 Tohoku-oki earthquake, Shinmoedake volcano, located on the Japanese island of Honshu, erupted. Was this eruption triggered by the Tohoku-oki earthquake? Could Mount Fuji and Changbaishan volcanoes also be triggered to erupt? By calculating changes in the regional stress-strain field that resulted from the earthquake, we find that Mount Fuji, Shinmoedake and Changbaishan volcanoes are all located in regions of volumetric expansion. The volumetric expansions at a depth of 10 km are up to ∼220 nano-strain, ∼8 nano-strain, and ∼14 nano-strain, respectively, for the three volcanoes. The strain changes inferred from GPS co-seismic displacements also suggest that these three volcanoes are located in regions with surface areal expansion. Considering that the expansional stress may cause the opening of magma channels, exsolution of CO2 gases stored in magma, and a series of positive feedback effects, the Tohoku-oki earthquake may result in an increase in the activity of these volcanoes. Attention should be paid to potential triggering of volcanic eruptions by stress changes induced by the Tohoku-oki earthquake.

Severe traumatic pneumocephalus in association with epistaxis: the "twin peaks" sign

An 88-year-old woman suffered recurrent falls. After one such fall, she presented with epistaxis, confusion, and progressive conscious decline. Her GCS was E4V3M5 and a CT showed a right-sided cribriform plate fracture (Fig. 1, top right) and severe pneumocephalus involving the extradural, subdural, intraventricular, and posterior fossa compartments (Fig. 1). Tension pneumocephalus was excluded as she slowly improved clinically (E4V4M6) and radiologically; the amount of intracranial air gradually reduced on high-flow oxygen. Pneumocephalus is common after neurosurgical and sinus procedures, but also after traumatic base of skull fractures. The Mount Fuji sign refers to tension pneumocephalus, when a ball-valve mechanism leads to air being trapped intracranially, causing brain compression [1]. Pneumocephalus has also been reported after tamponade for epistaxis [2]. We postulated the following mechanism: the patient developed chronic subdural hematoma (CSDH) due to recurrent falls; she suffered a skull base fracture, which allowed the CSDH to leak through the nose. Hence her ‘epistaxis’ was probably a blood-stained CSF leak, which allowed the intracranial pressure to drop, encouraging air to enter the subarachnoid/subdural space, by means of a dehiscence in the skull base, creating a CSF fistula. Figure 2 shows brain reexpansion on follow-up neuroimaging at 10 weeks. In the Mount Fuji sign, the frontal lobes are collapsed by pneumocephalus in the convexity of each hemisphere. The significance of the "twin peaks" sign is two-fold:

Does the Mount Fuji Sign always signify ‘tension’ pneumocephalus? An exception and a reappraisal

Pneumocephalus is expected after any craniotomy and usually resolves without any sequelae. However if the air entering the cranial cavity gets entrapped, it can lead to tension pneumocephalus and can have disastrous consequences. It is of utmost clinical importance to differentiate a tension pneumocephalus from a non-tension pneumocephalus as the latter does not usually require decompressive surgery. CT scan is considered the gold standard and diagnostic modality of choice for the diagnosis of pneumocephalus in the post-operative period. The Peaking sign and Mount Fuji sign are proposed as fairly specific for tension pneumocephalus, the latter being the most specific and an important sign to differentiate it from non-tension pneumocephalus. We present a case of a 20 year old male whose post-operative CT brain showed the typical Mount Fuji sign suggestive of tension pneumocephalus but was managed conservatively without any decompressive surgery.

Changes in Air Temperatures on Mount Fuji, Japan

The changes in air temperatures on Mount (Mt.) Fuji, Japan were evaluated. Various parameters of air temperatures on Mt Fuji in Japan were obtained from Japan Metrological Agency. Parameters of air temperatures were positively correlated with years on Mt. Fuji. In addition, the number of days under –24°C in January was negatively correlated with years. Global warming was also proved on Mt. Fuji in Japan, especially in winter. Therefore, we need to deal with global warming effect.

The Formation and Development of Mount Fuji's Imagery Through JapaneseClassic Literature from the Nara Era Until Muromachi Era

The Formation and Development of Mount Fuji's Imagery Through JapaneseClassic Literature from the Nara Era Until Muromachi Era

Conquering Mount Fuji: Resolution of Tension Pneumocephalus with a Foley Urinary Catheter

Tension pneumocephalus is the presence of air or gas in the cranium that is under pressure. It occurs due to disruption of the skull, including trauma to the head or face, after neurosurgical procedures and occasionally, spontaneously (Schirmer et al., 2010). Patients typically present with headache but can also have neurological deficits such as decreased mental status, numbness, and weakness (Schirmer et al., 2010). It is diagnosed by computerized tomography (CT) scan (Michel, 2010). The characteristic finding is that the two frontal poles of the brain are separated by air. After diagnosis, treatment is imperative for both symptomatic relief and preventing further compression. We present a case of a patient who presented with tension pneumocephalus and unconventional treatment that resulted in clinical improvement of his symptoms and radiographic resolution of his condition.

The role of arbuscular mycorrhizae in primary succession: differences and similarities across habitats

Abstract. Primary succession is an ecological process of fundamental importance referring to the development of vegetation on areas not previously occupied by a plant community. The bulk of knowledge on primary succession comes from areas affected by relatively recent volcanic eruptions, and highlights the importance of symbiosis between host plants and fungi for the initial stages of succession. Arbuscular mycorrhizas (AM) are of particular interest as they are often present from the very beginning of primary succession and because they show different relationships with pioneer and late-successional species, which suggests they may be involved in important, yet unknown, ecological mechanisms of succession. We review existing knowledge based on case studies from the volcanic desert of Mount Fuji, Japan, where primary succession was examined intensively and which represents one of the best-known cases on the role of AM in primary succession. We also assess the potential of sand dunes and semi-arid, erosion-prone systems for addressing the role of mycorrhizas in primary succession. Analyzing primary succession under different ecological systems is critical to understand the role of AM in this basic process. While volcanoes and glaciers are restricted to particular mountainous areas, naturally eroded areas and sand dunes are more common and easily accessible, making them attractive models to study primary succession.

Evolution of Mount Fuji, Japan: Inference from drilling into the subaerial oldest volcano, pre‐Komitake

AbstractA buried, old volcanic body (pre‐Komitake Volcano) was discovered during drilling into the northeastern flank of Mount Fuji. The pre‐Komitake Volcano is characterized by hornblende‐bearing andesite and dacite, in contrast to the porphyritic basaltic rocks of Komitake Volcano and to the olivine‐bearing basaltic rocks of Fuji Volcano. K‐Ar age determinations and geological analysis of drilling cores suggest that the pre‐Komitake Volcano began with effusion of basaltic lava flows around 260 ka and ended with explosive eruptions of basaltic andesite and dacite magma around 160 ka. After deposition of a thin soil layer on the pre‐Komitake volcanic rocks, successive effusions of lava flows occurred at Komitake Volcano until 100 ka. Explosive eruptions of Fuji Volcano followed shortly after the activity of Komitake. The long‐term eruption rate of about 3 km3/ka or more for Fuji Volcano is much higher than that estimated for pre‐Komitake and Komitake. The chemical variation within Fuji Volcano, represented by an increase in incompatible elements at nearly constant SiO2, differs from that within pre‐Komitake and other volcanoes in the northern Izu‐Bonin arc, where incompatible elements increase with increasing SiO2. These changes in the volcanism in Mount Fuji may have occurred due to a change in regional tectonics around 150 ka, although this remains unproven.

Cover Picture: Eur. J. Immunol. 7/10

The cover image for this issue has been designed in honor of the 14th International Congress of Immunology (ICI, August 22–27, 2010; www.ici2010.org), to be held in Kobe, Japan. The Kanji characters were proposed by the organizers of the meeting, and represent the study () of immunity (), i.e. immunology (). Underneath, the characters for creativity (), dream (), and future () are shown and represent the concept that, with creativity and some inspiration, we may anticipate a bright future for immunological studies. The image is a composition of the classic Japanese woodprint Mount Fuji in Clear Weather (also known as Red Fuji) by Katsushika Hokusai and immunofluorescent staining of CD248 in wild-type MEF, adapted from an article in this issue by Lax et al. (pp. 1884–1889)

Magnetic-field angle dependent critical current densities and flux pinning in commercial YBCO tapes at liquid nitrogen temperatures

The magnetic-field angle dependence of critical current densities J c ( H,θ) in commercial YBCO tapes grown by MOCVD and MOD was examined at liquid nitrogen temperatures. We first measured J c ( H, θ) in MOCVD-YBCO tapes at 70 and 77.3 K in fields up to 2 T using both transport and inductive (the third harmonic voltage) methods and compared the results. It was observed that, in low magnetic fields, the transport measurements gave higher J c than the inductive ones; however, in high fields they agreed well, which is well explained by the effects of weak links due to low-angle grain boundaries. We then investigated J c ( H, θ) in MOCVD- and MOD-YBCO tapes at 77.3 K in fields up to 2 T. All the tapes exhibited peaks at H// ab in the shape of Mount Fuji, which shows that small random pinning plays a major role. However, an anisotropic scaling analysis showed that the flux pinning mechanisms in those tapes were different, resulting in distinctive angular behaviors of J c ( H, θ). It is suggested that the difference in the flux pinning mechanisms of the two types of tapes came from the different sizes of point defects originating from the growing processes.

Tension pneumocephalus as complication of burr-hole drainage of chronic subdural hematoma: A case report

Background:Pneumocephalus is the presence of air in the cranial cavity. When this intracranial air causes increased intracranial pressure and leads to neurological deterioration, it is known as tension pneumocephalus (TP). TP can be a major life-threatening postoperative complication, especially after evacuation of chronic subdural hematoma. We report a case of TP after evacuation of chronic subdural hematoma and review the literature.Case Description:A 70-year-old man developed right-sided weakness after being admitted with minor head trauma a few weeks earlier. He was found to have a chronic subdural hematoma and underwent burr-hole evacuation. On day 3, he suddenly deteriorated and needed intubation and ventilation. Computerized tomography (CT) of the brain showed typical Mount Fuji’s sign due to TP. Immediately, 20-30 mL of air was aspirated from the intracranial fossa, and a catheter drain was inserted. The patient became fully awake after few hours and was extubated successfully. The drain was removed on day 5, and he was transferred to the ward before being discharged home.Conclusion:TP after evacuation of a chronic subdural hematoma is a neurosurgical emergency and needs immediate resuscitation and therapy; hence it is of vital importance that all acute-care physicians, intensivists and neurosurgeons be aware of this clinical emergency.

Neoaleurodiscus fujii, a new genus and new species found at the timberline in Japan

A new genus, Neoaleurodiscus, is proposed as a segregate from Aleurodiscus (Basidiomycota), and the new species, Neoaleurodiscus fujii, is described. It was collected at the timberline of Mount Fuji, Japan. Specimens were found on trunks of Rhododendron sp. Morphological study and phylogenetic analysis based on sequence data derived from LSU nrDNA indicated that Neoaleurodiscus is separate from other segregate genera from Aleurodiscus s.l. Neoaleurodiscus is characterized by having a disciform basidiocarp; microscopically it has moniliform gloeocystidia, absence of acanthophyses, nodose-septate hyphae, hyphidia, and basidiospores, which are amyloid, smooth and ± thick-walled. Among genera studied Acanthobasidium and Aleurodiscus (s.s.) are most closely related to Neoaleurodiscus, but these genera have warted or spiny basidiospores. Two new combinations, Acanthobasidium penicillatum and Neoaleurodiscus monilifer, are proposed.

Mount Fuji Sign in tension pneumocephalus

A 64-year-old male reported 36 hours after sustaining injuries to head and face in a road-traffic accident. He was conscious and alert with Glasgow Coma Scale of 15/15. Non-contrast computed tomography (NCCT) head revealed fracture of frontal sinus extending to right orbital roof with pneumocephalus depicting classical Mount Fuji sign (Fig 1). Since patient was neurologically intact and did not have any cerebrospinal fluid leak, he was managed conservatively with decongestants and oxygen by mask. Recovery was uneventful with resolution of pneumocephalus.

Gary Snyder, Alan Hovhaness, and Writing the Blast

“The twisting strata of the great mountains and the pulsings of great volcanoes are my love burning deep in the earth.” Those who knew the Pacific Northwest's volcanoes more than a generation ago will agree that the slighter Mount St. Helens, which tribal peoples knew as Loowit (“Smoker, Smoky”), rose as the most symmetric and shapely—of all the West coast's volcanoes, the one most closely approximating a bell curve, the Platonic form of volcano—and that St. Helens often drew comparisons with Japan's Mount Fuji. Since our country's premiere contemporary volcanic event, on May 18, 1980, St. Helens—a sprawling horseshoe, 1300 feet lower and open to the north, a truncated mountain no longer closing in a circle—requires different eyes and understanding. For those used to conventional visual clichés, it lost its grace, turned homely. Two Northwestern artists, a poet and a composer, have offered us lenses through which to understand the old and new mountain, before and after the blast.

Bartonella japonica sp. nov. and Bartonella silvatica sp. nov., isolated from Apodemus mice

Two bacterial strains, Fuji 18-1(T) and Fuji 23-1(T), were isolated from the blood of the small Japanese field mouse (Apodemus argenteus) and the large Japanese field mouse (Apodemus speciosus), respectively, specimens of which were captured in the forest of Mount Fuji, Japan. Phenotypic characterization (growth conditions, incubation periods, biochemical properties and cell morphologies), DNA G+C contents (40.1 mol% for strain Fuji 18-1(T) and 40.4 mol% for strain Fuji 23-1(T)) and sequence analyses of the 16S rRNA genes indicated that both strains were members of the genus Bartonella. Using rpoB and gltA sequencing analysis, the highest sequence similarities between strains Fuji 18-1(T), Fuji 23-1(T) and other recognized species of the genus Bartonella showed values considerably lower than 91.4 % and 89.9 % in the rpoB gene and 89.1 % and 90.4 % in the gltA gene, respectively. It is known that similarities of 95.4 % for the rpoB gene and 96.0 % for the gltA gene can be applied as cut-off values for the designation of novel species of the genus Bartonella. In a phylogenetic tree based on the merged set of concatenated sequences of seven loci [16S rRNA, ftsZ, gltA, groEL, ribC and rpoB genes and the intergenic spacer region (ITS)], strains Fuji 18-1(T) and Fuji 23-1(T) formed a distinct clade from other recognized species of the genus Bartonella. These data support the classification of strains Fuji 18-1(T) and Fuji 23-1(T) as novel species of the genus Bartonella. The names Bartonella japonica sp. nov. and Bartonella silvatica sp. nov. are proposed for these novel species. The type strains of Bartonella japonica sp. nov. and Bartonella silvatica sp. nov. are Fuji 18-1(T) (=JCM 15567(T)=CIP 109861(T)) and Fuji 23-1(T) (=JCM 15566(T)=CIP 109862(T)), respectively.

Yoji Totsuka

Yoji Totsuka, an honorary professor emeritus at the University of Tokyo, died of cancer on 10 July 2008 in Kashiwa, Japan. He will be most remembered for his leadership on the Super-Kamiokande experiment, which discovered that neutrinos have tiny, nonzero masses.Born in Fuji City, near Japan’s Mount Fuji, on 6 March 1942, Totsuka spent most of his boyhood in the area. After he graduated with a degree in physics from the University of Tokyo in 1965, he entered the university’s graduate course in physics under the supervision of Masatoshi Koshiba. Totsuka’s thesis work, for which he received his PhD in 1972, was on the underground measurement of the flux of cosmic-ray muon bundles at the Kamioka mine. Thus began his 30-year research career in Kamioka.From 1972 to 1981, Totsuka worked on the DASP and JADE e+e− experiments at DESY, the German Electron Synchrotron in Hamburg. He returned to Tokyo in 1981 and joined Koshiba’s Kamiokande experiment, which used a 3-kiloton water Cherenkov detector to search for proton decay; it began operating in July 1983. Because the detector worked so well, two new ideas were soon proposed: the detection of solar neutrinos in Kamiokande and the construction of a 50-kiloton water Cherenkov detector, Super-Kamiokande. From 1984 to early 1987, the detector underwent a major improvement so it could detect solar neutrinos. Luckily, that work was finished one month before the arrival of supernova neutrinos in February 1987.After Koshiba retired from the University of Tokyo, Totsuka was appointed leader of the Kamiokande and Super-Kamiokande experiments in April 1987. To realize the Super-Kamiokande project, he moved to the university’s Institute for Cosmic Ray Research (ICRR) the following year.Thanks to Totsuka’s effort, in 1991 Super-Kamiokande was approved by the Japanese government. A large number of US collaborators joined the experiment; of the roughly 100 researchers, about 60% were from Japan and 40% from the US. The construction was scheduled for completion on 31 March 1996, the end of Japan’s 1995 fiscal year; the Super-Kamiokande experiment came on line as scheduled at midnight on 1 April.Totsuka’s strong leadership kept the construction on track, and his engaging character helped the collaboration work cohesively toward its goal. His warmth and friendliness made him very easy to work with.From the beginning of Super-Kamiokande, its primary goals were clear: to resolve why experiments detected fewer solar neutrinos than predicted by theory and to explain anomalous observed ratios of atmospheric neutrinos. Through the detailed studies of atmospheric neutrinos, Totsuka and his colleagues in 1998 discovered neutrino oscillations between muon neutrinos and tau neutrinos and thus solved the atmospheric neutrino anomaly. In 2001 they determined, from solar neutrino data gathered by Super-Kamiokande and the Sudbury Neutrino Observatory (SNO) in Canada, that the solar neutrino deficit was due to neutrino oscillations between electron neutrinos and the other types. Those discoveries implied that neutrinos have tiny, nonzero masses, and they were the first experimental evidence for physics beyond the standard model of particle physics. Due to those fundamental contributions to the field, Totsuka was honored with numerous prizes and awards, including the Franklin Institute’s Franklin Medal, which he received in 2007 with Art McDonald, leader of the SNO experiment.Totsuka’s excellent leadership skills were especially critical to the collaboration when an accident on 12 November 2001 destroyed more than half of the photomultiplier tubes in Super-Kamiokande. The following day he declared that the detector would be reconstructed. In a letter posted on the home page of the ICRR’s Kamioka Observatory, he wrote to his colleagues, “We will rebuild the detector. There is no question.” Without Totsuka’s guidance, the present, rebuilt Super-Kamiokande could not have been imagined.As a result of his science and management skills, Totsuka was asked to serve in numerous leadership positions: as director of the ICRR from 1997 to 2001; as director general of Japan’s high-energy physics organization, KEK, from 2003 to 2006; and as director of the Research Center for Science Systems of the Japan Society for the Promotion of Science from 2006 to 2008. He kept working on proposals and making important decisions until right before his death.Totsuka pushed the next-generation neutrino oscillation experiment, the T2K (Tokai to Kamioka), which is scheduled to start in late 2009. Although he will not see the project through, his younger colleagues continue his dedication by exploring neutrinos to better understand the physics of elementary particles and the universe. Yoji Totsuka JAPAN SOCIETY FOR THE PROMOTION OF SCIENCEPPT|High resolution© 2009 American Institute of Physics.

Intrinsic and scattering attenuation of the Mt Fuji Region, Japan

Mount Fuji is the focus of intense study because of its potential hazard signaled by seismic, geologic and historical activity. Based on extensive seismic data recorded in the vicinity of Mt Fuji, coda quality factor (Q−1C) using a single scattering model hypothesis, and intrinsic and scattering quality factor (Q−1i and Q−1S) using the Multiple Lapse Time Window (MLTW) method were measured. To focus the study on the magmatic structure below Mt Fuji, the data were separated into two groups: a near-Fuji region of rays traversing an area with radius 5 km around the summit (R < 5 km), and a far-Fuji region of rays beyond a radius of 20 km around the summit (R > 20 km). This classification shows the largest discrepancy of Q−1C at a range of sampling volumes corresponding to overlapped sampling depth of about 80 km. Further, the spatial division shows significant difference of Q−1i and Q−1s at hypocentral distance of 80 km. The large difference of Q−1s in bandwidths 2–4, and 4–8 Hz indicates lithospheric heterogeneity beneath Mt Fuji with a characteristic heterogeneity scale length of about 1 km. The results have a small error range due to the large data sample, showing that all Q−1 values in the near-Fuji area are greater than those of the far-Fuji area, and Q−1i for both the near and far-Fuji areas is higher than Q−1s at high frequencies. The Q−1i and Q−1s values for far-Fuji are in the range of values for typical non-volcanic areas. The Q−1i values of the near-Fuji area are lower than those of other volcanic areas considered, where as values of Q−1s are not. The low Q−1i for the volcanic region of near-Fuji suggests that the magmatic activity, indicated by percent partial melt, in the vicinity of Mt Fuji is not as active as hot spot volcanoes, such as Kilauea, Hawaii.

Post-traumatic pneumocephalus

A 79-year-old male presented to the emergency department after a facial trauma because of a mechanical fall 3 h prior with no history of loss of consciousness. The patient had Parkinson’s disease and atrial fibrillation (AF), and was on treatment with acetylsalicylic acid for AF. The family reported that he was dependent for all basic daily activities and had mild cognitive deterioration. Physical examination showed that he was lethargic, but oriented, bradykinetic, and had gait and balance difficulty. No headache or confusion was reported. All cranial nerves were intact, and there were no motor or sensory deficits. He had superficial lacerations in the nasal and frontal regions. Nasal and ocular orbit X-rays were taken, showing nasal fracture and pneumocephalus (Fig. 1). Computed tomography scan confirmed pneumocephalus and multiple craniofacial fractures (Fig. 2). After a week of observation and prophylactic antimicrobial therapy during which there was no clinical deterioration, the patient was discharged. At follow-up 5 weeks later, the patient was at his clinical baseline. Repeated imaging showed progressive resolution. Fig. 1 X-ray showing nasal and orbital fractures and pneumocephalus Fig. 2 Large right pneumocephalus compressing right frontal lobe and widening interhemispheric space. There are also air bubbles in basal cisterns and cerebellar fissures bilaterally Pneumocephalus is the presence of air in the cranial vault. It is usually associated with neurosurgery, barotrauma, basilar skull fractures, sinus fractures, nasopharyngeal tumor invasion and meningitis [1, 2]. Headache and altered consciousness are the most common symptoms [3]. Tension pneumocephalus can occur and is a neurosurgical emergency [4]. Plain X-rays can diagnose pneumocephalus, but CT scan is the diagnostic modality of choice [5]. A classical CT sign of tension pneumocephalus is the “Mount Fuji sign”: the massive accumulation of air that separates and compresses both frontal lobes and mimics the profile of the large volcano in Japan. In our case, the air only compressed the right frontal lobe. Most cases of pneumocephalus resolve spontaneously, and conservative management should be provided. Nonoperative management involves oxygen therapy, keeping the head of the bed elevated, prophylactic antimicrobial therapy (especially in post-traumatic cases), analgesia, frequent neurologic checks and repeated CT scans.