[Hospital Discharge Arrangements for Very Elderly Patients with Chronic Subdural Hematoma].

INTRODUCTION: Chronic subdural hematoma(CSDH)is a common condition encountered by neurosurgeons. Owing to increasing life expectancy and rapid population aging, the age at disease onset is delayed, which negatively affects hospital discharge arrangements. This retrospective study investigated patients aged ≥90 years who underwent surgery for CSDH. SUBJECTS AND METHOD: The study included 53 patients diagnosed with CSDH(63 sides)for the first time, who underwent surgery at our hospital between April 2018 and March 2019. The mean age was 78.7 years, and the study included 40 men. A subdural drain was placed after burr hole surgery performed for hematoma evacuation and lavage. The basic protocol included 8-day hospitalization comprising surgery on the day of admission, rehabilitation initiated the day after surgery, and suture removal 7 days after surgery, followed by hospital discharge. The 'elderly' group(Group E)included patients aged ≥90 years, and the 'others' group(Group O)included patients aged <90 years. This study focused on hospital discharge arrangements. RESULTS: The mean length of hospitalization was 7.6 days in 10 patients(19%)in Group E. The rate of intervention by a discharge support nurse or medical social worker(Medical Consultation Team)was 100% in Group E and 65% in Group O. All patients were discharged to planned living arrangements with the assistance of the Medical Consultation Team and rehabilitation intervention. CONCLUSION: Among elderly patients, difficulties with hospital discharge arrangements could be attributed to exacerbation of dementia symptoms after hospitalization and manifestations of disuse syndrome and complications. Surgical treatment can be offered to patients with CSDH regardless of age(even to those aged >90 years)and facilitates smooth discharge with multidisciplinary intervention.

The use of a fiber sleeve to improve fracture strength of pulpless teeth with flared root canals.

OBJECTIVES: This study aimed to investigate how use of a fiber sleeve may reduce interfacial debonding and improve fracture strength of pulpless teeth with flared root canals. METHODS: Pulpless premolars with flared root canals were restored either with a fiber-reinforced post (FRP) alone or with an FRP wrapped in a hollow tubular fiber sleeve. A normal root restored with an FRP alone served as a control. The integrity of resin-dentin and resin-fiber interfaces in the restored roots was evaluated by a stereoscopic system after penetrating a dye. Four roots were tested for each experimental group. Fracture resistance in pulpless premolars with flared root canals restored with an FRP alone or with an FRP/sleeve combination were investigated under bonded and non-bonded conditions with static fracture testing (n=8), and stress distribution in these restored premolars were tested by finite element analysis (FEA). RESULTS: Flared root canals restored with an FRP/sleeve combination demonstrated superior integrity at the cervical resin-dentin interface to root canals with an FRP alone. Premolars with a flared root canal restored with an FRP/sleeve combination showed significantly greater fracture resistance compared with premolars restored with an FRP alone. FEA showed that once interfacial de-bonding extended to the cervical region of the root, stress concentration in the root dentin dramatically increased. SIGNIFICANCE: The FRP/sleeve combination was effective in reducing debonding and, hence, improving the fracture strength of pulpless premolars with flared root canals.

Fracture strength and stress distributions of pulpless premolars restored with fiber posts.

This study examined the effect of glass fiber posts on increasing the fracture resistance of endodontically treated teeth. Extracted upper premolars with two canals in a root were divided into three groups according to the number of posts they were restored with: none, one, or two. All teeth were endodontically treated, crown-sectioned, and restored with a composite core and a metallic crown. A static oblique load was applied to the restored tooth until fracture, and the fracture pattern was recorded. Stress distributions were examined by finite element analysis (FEA). Teeth with glass fiber post(s) showed significantly higher fracture loads compared with those without posts. In the premolars without posts, von Mises and maximum principal stresses were found on the root surface alone; in premolars restored with posts, stresses were distributed on both root and post surfaces. Risk of root dentin fracture was significantly lowest in teeth restored with two posts.

[A case of solitary bone cyst in the skull increasing in size after trivial head injury].

A 12-year-old boy had been known to have a small swelling in the left high vertex for several years. After a trivial head hit to the site of the swelling, the swelling enlarged gradually. A bone window CT scan showed a lesion having bubble-like lytic change in the left parietal bone. Similar changes, but small, were able to be pointed out in a CT scan taken seven years previously. In the following 13 months CT scans eventually revealed sequential increases to 3.5 cm in diameter. Surgical exploratory resection of the mass was performed. Intraoperatively, partial destruction of the outer skull table and a simple cyst with serous yellowish brown colored fluid were identified. There was no finding adherent to the diploic structure. The bone defect after excision was reconstructed by using a titanium plate. The patient was followed up for 2 years after the surgery. Bone window CT showed bony development of normal appearance. Histological examination showed the cyst wall consisted of fibrous connective tissue but there were neither epithelial nor endothelial cells. The histopathological diagnosis of SBC was most likely. SBC is relatively common in long bones, but rarely in flat bones. Only several cases of the SBC of cranial bone have been reported. Although a craniectomy for total excision followed by cranioplasty by resin was common, in cases of children, cyst removal with titanium plate application would be an alterative. SBC increasing in size after head injury is extremely rare, but clinicians may need to be aware of cystic skull bone tumors increasing in size after head injury.

Effects of heating on the mechanical and chemical properties of human dentin.

OBJECTIVES: We had previously discovered that the flexural and tensile strengths of human dentin were 2-2.4 times greater after being heated to 140°C, and deduced that the generation of higher-density structures and therefore dehydration probably promoted the increased strength. Our test hypotheses were that intertubular dentin, which constitutes a major part of organic components, was selectively affected by heating, and such changes could happen without critical damages to the basic structure of dentin type I collagen. METHODS: Micro-mechanical changes of human dentin by heating at 140°C were investigated by nano-indentation. Chemical changes in dentin collagen after heating were also investigated by X-ray diffraction study, a microscopic Fourier transform infrared (micro-FTIR) and a laser Raman spectroscopic analyses, and a cross-linking analysis by high-performance liquid chromatography. RESULTS: The results of nano-indentation showed that the micro-hardness of intertubular dentin increased after heating at 140°C to 1.8 times more than unheated dentin; on the other hand, peritubular dentin was unchanged. Results of X-ray diffraction showed that the lateral packing of collagen molecules shrank from 13.6±0.3 to 10.6±0.1Å after heating, but the shrinkage reversed to the original after rehydration for seven days. After heating, no substantial chemical changes in the collagen molecules were detected in tests by micro-FTIR or Raman analyses, or by cross-linking analysis. SIGNIFICANCE: These results suggest that intertubular dentin, which contains most of the type I collagen, was selectively affected by heating at 140°C without critical damage to its collagen.

Intracranial foreign body granuloma caused by dural tenting suture.

Our patient presented with a mass lesion mimicking a meningioma. The mass was resected, but pathological examination confirmed a foreign body granuloma, which was caused by silk fibres used as tenting sutures 8 years previously. Herein, we describe the case and review the neurosurgical literature on intracranial foreign body granulomas.

[A complicated case of Nocardia brain abscess for differential diagnosis].

BACKGROUND: Nocardia brain abscess is rare and has uncertain clinical features. Radiological differential diagnosis based on the metabolic feature of Nocardia is discussed. CASE DESCRIPTION: A 73-year-old man presented with a history of otitis media and was treated with antibiotics for 2 weeks. Computed tomography (CT) and magnetic resonance imaging (MRI) demonstrated an irregular ring-enhancement mass in the left cerebellar hemisphere. This lesion presented as a homogeneous high-intensity area in diffusion-weighted MRI. We also found decreased N-acetyl-aspartate (NAA) peak and increased choline and lipid peaks in proton MR spectroscopy (1H-MRS). We performed an aspiration. Nocardia asiatica in the mass lesion was found by genetic analysis. The patient was treated with a sulfamethoxazole/trimethoprim (ST) mixture and minocycline (MINO) intravenously for 6 months. There has been no recurrence for 2 years. CONCLUSIONS: To our knowledge, this case is the first case of Nocardia asiatica brain abscess in Japan. We considered these MRS findings to be compatible with Nocardia brain abscess as mainly observed in aerobic metabolism. But we also detected a lactate peak in the abscess. Further research is required.

The persistence of an open anterior fontanel in a 4-year-old girl.

CASE REPORT: A 3-year-old girl was transferred to our hospital with a history of persistent open anterior fontanel. The patient was conscious and had no neurological deficits. Upon arrival, the patient appeared normal for her age and had no defects or anomalies other than the aforementioned lesion. The initial skull X-ray and CT were significant for a 20-mm open anterior fontanel. All other findings were normal. OUTCOME: After a follow-up period of 1.5 years, the anterior fontanel was still open, with a slight decrease in size to 15 mm. Delayed closure of the anterior fontanel without intracranial hypertension is associated with various disorders. The pathogenesis of the current patient's condition is unclear. Due to the patient's normal appearance and stable neurological status, we will follow her conservatively for any changes in condition.

Radiation-induced temporary hair loss as a radiation damage only occurring in patients who had the combination of MDCT and DSA.

As imaging technologies become increasingly advanced, it is possible to obtain detailed morphological information as well as functional imaging data. In some imaging technologies, the radiation dose increases with the ability to obtain better images or more detailed information. We encountered three cases of temporary bandage-shaped hair loss, which was caused by perfusion studies of the head by multi-detector row computed tomography (MDCT) for evaluation of cerebral blood flow in patients with vascular disorders. In all three patients with temporary hair loss, two angiographies of the head had been performed in the period of serial CT examinations. This suggested the possibility that radiation exposure from angiography performed in serial examinations, combined with the perfusion studies of the head with MDCT, played an important role in this temporary, bandage-shaped hair loss. Radiologists should be aware that a cumulative or multiplier effect of radiation exposure from multiple diagnostic techniques may result in hair loss and other types of radiation complications.

Comparison of cerebral blood flow in computed tomographic hypodense areas of the brain in head-injured patients.

OBJECTIVE: Hypodense lesions identified on computed tomographic (CT) scans are often assumed to indicate ischemia. The purpose of this study was to investigate regional cerebral blood flow (rCBF) in hypodense areas of the brain after severe traumatic brain injury. METHODS: CBF was measured by stable xenon-enhanced CT scans. Hypodense areas were identified, and rCBF values as well as CT density were averaged for the region. RESULTS: Thirty (60%) of the 50 patients had a total of 45 hypodense regions, which were associated with either contusion (n = 30) or areas of infarction (n = 15). rCBF in the hypodense regions was variable, ranging from a low of 3.3 to a high of 72.5 ml/100 g/min. The cause of the lesion was the major factor associated with the level of rCBF. Although the average decrease in CT density was similar for the two types of lesions, the average rCBF was significantly lower and the difference in rCBF between the lesion and the contralateral side was greater when the hypodense lesion was associated with a contusion. A critical reduction in rCBF (<20 ml/100 g/min) was found in 19 (63%) of the hypodense regions associated with contusions but in only 4 (27%) of those from areas of infarction. CONCLUSION: Hypodensity on plain CT scans does not always indicate reduction in CBF. This association was found more commonly when the low-density area was associated with a contusion. In hypodense areas associated with infarction, rCBF was variable and not commonly in the ischemic range at the time the CBF measurement was obtained.

Dynamic autoregulatory response after severe head injury.

OBJECT: The purpose of this study was to evaluate the extent and timing of impairment of cerebral pressure autoregulation after severe head injury. METHODS: In a prospective study of 122 patients with severe head trauma (median Glasgow Coma Scale Score 6), dynamic tests of pressure autoregulation were performed every 12 hours during the first 5 days postinjury and daily during the next 5 days. The autoregulatory index ([ARI] normal value 5 +/- 1.1) was calculated for each test. The changes in the ARI over time were examined and compared with other physiological variables. The ARI averaged 2.8 +/- 1.9 during the first 12 hours postinjury, and continued to decrease to a nadir of 1.7 +/- 1.1 at 36 to 48 hours postinjury. At this nadir, in 87% of the patients the value was less than 2.8. This continued deterioration in the ARI during the first 36 to 48 hours postinjury occurred despite an increase in cerebral blood flow ([CBF], p < 0.05) and in middle cerebral artery blood flow velocity ([BFV], p < 0.001), and could not be explained by changes in cerebral perfusion pressure, end-tidal CO2, or cerebral metabolic rate of O2. A marked decrease in cerebrovascular resistance ([CVR], p < 0.001) accompanied this deterioration in the ARI. Patients with a relatively higher BFV on Day 1 had a lower CVR (p < 0.05) and more impaired pressure autoregulation than those with a lower BFV. CONCLUSIONS: The inability of cerebral vessels to regulate CBF normally may play a role in the vulnerability of the injured brain to secondary ischemic insults. These studies indicate that this vulnerability continues and even increases beyond the first 24 hours postinjury. Local factors affecting cerebrovascular tone may be responsible for these findings.