Enhanced vertical alveolar bone augmentation by recombinant human bone morphogenetic protein-2 with a carrier in rats.

This study aimed to evaluate the effect of recombinant human bone morphogenetic protein-2 (rhBMP-2) on vertical bone regeneration of edentulous ridge. Bilateral upper first and second molars of 8-week-old Wistar rats were extracted and the ridges were allowed to heal for 3 weeks. Compressed poly(lactic-co-glycolic acid) copolymer/gelatin sponge (PGS) was used as a carrier of rhBMP-2. PGS alone (control group) or PGS with 5 mug rhBMP-2 (test group) was implanted at the top part of alveolar ridge. The sham group received no implantation. The rats were killed at 1, 2, 4, 8 and 12 weeks after implantation and examined histologically and histomorphometrically. In the test group, significant bone augmentation was evident on the alveolar ridge throughout the experimental period. Histomorphometric analysis revealed greater tissue volume and height of alveolar bone in the test group compared with the control and sham groups (P < 0.05) from 4 weeks onward and the augmented tissues (5 mm3 in tissue volume and 1.5 mm in bone height) were maintained until 12 weeks. Osteoblast surface increased at 2 and 4 weeks and osteoid thickness reached a peak (25 microm) at 2 weeks. Dynamic variables, which represented calcification, were higher in the test group than the control and sham groups at 4 and 8 weeks (P < 0.05). These results suggest that use of rhBMP-2/PGS may achieve vertical bone augmentation, and stabilizes denture prosthesis or makes up for inadequate bone mass for implant prosthesis.

Hemifacial spasm in childhood and adolescence.

Hemifacial spasm (HFS), a hyperactive dysfunction of the facial nerve, is rarely seen in young people. Between 1984 and 1994, we treated 924 patients with HFS by microvascular decompression at our institution. Of these, 8 (0.9%) were younger than 30 years. In most of the older patients with HFS, the offending artery which compresses the root exit zone was elongated, redundant, and focally arteriosclerotic as a result of hemodynamic effects due to aging or hypertension. On the other hand, the offending artery did not exhibit such characteristic changes of the vasculature in children and adolescents with HFS. In all of the young patients who underwent initial microvascular decompression at our clinic, the arachnoid membrane around the facial nerve was thickened and encased the artery, resulting in compression of the root exit zone of the facial nerve. Such thickening of the arachnoid surrounding the offending vessel may play an important role in the pathogenesis of HFS by trapping and encasing the artery to compress the root exit zone, particularly in the young patients.

[Studies concerning the pathogenesis of trigeminal neuralgia caused by cerebellopontine angle tumors].

It has been well recognized that neurovascular compression can elicit trigeminal neuralgia (TN) and microvascular decompression surgery has become popular as a radical treatment of this clinical symptom. Cerebellopontine (C-P) angle tumors, however, as well known, can also cause TN. Four hundred fifty six patients with TN underwent posterior fossa exploration between 1984 and 1992 in our clinic, and among them, 45 (9.9%) patients harbored C-P angle tumors which were causative of TN. They included 22 epidermoids, 18 meningiomas and 5 neurinomas. The patient population consisted of 35 women and 10 men, ranging in age from 28 to 73 years, with a mean age of 51.7 years. The mean age of the patients of TN with tumors is considerably lower than that of neurovascular compression patients (61.0 years), particularly in cases of neurinomas (44.4 years) and epidermoids (48.0 years) (p < 0.01). Such difference in ages at the onset of symptom may be explained by the fact that the tumor growth in the C-P angle develops earlier than changes of the vasculature of the vertebrobasilar artery system by aging. Anatomical relationships between the 5th cranial nerve and offending arteries or tumors verified at surgery are as follows; Type A: The nerve is totally encased by the tumor. Type B: The axis of the nerve is distorted by the tumor. Type C: The nerve is shifted by the tumor and is compressed by the artery contralaterally. Type D: The nerve is compressed by the artery which was displaced by the tumor.(ABSTRACT TRUNCATED AT 250 WORDS)

[Treatment of intractable postherpetic neuralgia and blepharospasm: intraneural injection of adriamycin].

Adriamycin, an anthracycline antineoplastic agent, can swiftly be transported to the sensory or somatic motor neurons by way of axoplasmic transport when injected into the subepineurium of the trigeminal nerve or sciatic nerve in experimental animals, and is consequently able to induce degeneration of the neurons without any systemic side effects. Intraneural injection of this agent was carried out for the treatment of a total of 22 patients presenting with intractable neural dysfunction (12 with neuralgia, including 7 with post-herpetic neuralgia and 10 with facial dystonia). The nerve which innervated the affected site was exposed under local anesthesia and approximately 10-60 microliters of 1-20% adriamycin was injected into the subepineurium. Results of the treatment after average follow-up periods of 21.5 months were as follows: Out of 12 patients with neuralgia, good results were obtained in 2 cases (16.7%), fair results in 6 cases (50.0%) (overall effective rate 67.7%). There were no changes in symptoms in 4 cases (33.3%). Out of 10 patients with facial dystonia, good results were obtained in 2 cases (20.0%), fair in 2 cases (20.0%) (overall effective rate 40.0%), and no changes in symptoms in 6 cases (60.0%). No major complications were encountered during these procedures and, once symptoms had disappeared after the treatment, no recurrence of symptoms was experienced. This method clearly differs from other various kinds of simple peripheral neurotomy, since transection of the peripheral nerve does not cause any, destructive changes in the sensory ganglion or motor nucleus and, hence, symptoms may recur.(ABSTRACT TRUNCATED AT 250 WORDS)

Unusual presentation of brain metastasis from hepatocellular carcinoma--two case reports.

Two unusual cases of brain metastasis from hepatocellular carcinoma (HCC) are described. A 15-year-old boy presented with intracerebral hemorrhage from brain metastasis from HCC, and died of rebleeding 1 month after surgery. Cerebral metastatic HCC in a child is quite rare, and has not previously been reported. A 65-year-old male with a 2-year history of treatment for HCC presented with a brain metastasis from HCC without intracerebral hematoma manifesting as gradual onset of headache. Brain metastases from HCC presenting without intracerebral hemorrhage are rare.

Clipping of the anterior communicating artery to eliminate the contralateral blood supply in supratentorial large AVM of the carotid system. A report of 22 cases.

Large supratentorial arteriovenous malformations (AVMs) of the carotid system are vascularized by the ipsilateral internal carotid artery (ICA) and often, in addition, by the contralateral ICA via the anterior communicating artery (ACoA). In these AVMs we have previously advocated (1981) multiple staged operations with the progressive reduction of the blood stream passing through the AVM. In twenty-two cases, starting in 1983, the reduction of the blood stream into the shunt has been performed as a first operation by placing a clip on the middle of the ACoA through a pterional approach on the opposite side of the AVM before radical open surgery. Results were excellent when considering the control angiogram and the measurement of the blood velocity in the ICA opposite to the AVM side. There were no neurological complications and no mortality.

Classification of supratentorial arteriovenous malformations. A score system for evaluation of operability and surgical strategy based on an analysis of 66 cases.

A classification of arteriovenous malformations (AVM) is proposed, which is based on a retrospective analysis of the records and results of radical operation in 57 patients between 1983 and 1990. It represents the new developments and more recent technical facilities which influence operability of supratentorial AVMs. Predictability of outcome has been settled upon three groups of factors: anatomical, haemodynamical, and clinical. Anatomical factors are localisation and sectorisation of AVM, determination, caliber and straightening of feeding arteries. Haemodynamical factors are volume of AVM and vascular autoregulation, circulatory velocity of red blood cells in the main arteries of the neck and brain tissue cellular steal. Clinical factors are age, previous rupture of AVM, associated diseases and malformations of vital organs. Each of these factor groups has been divided into parameters to which a code number from 0 to 5 according to the severity of the considered parameter has been attributed. When a contraindication for radical surgery was clearly obvious, as, for example, an AVM with extension to the upper brain stem, number 10 was given. This grading has been done by a team of four persons (3 neurosurgeons including the senior author, and one biophysicist). By adding up all code numbers an Operability Score for a given patient is defined by the number of points, with a minimum of 3 and a maximum of 69. In cases with a score higher than 30 surgery is not advisable. A score between 21 and 30 indicates that always several staged operations are required, whilst only some of the patients with a score between 11 and 20 may require two stage operative treatment. The AVM in patients with a score under 10 can always be radically excised in a single stage operation. We have been able to demonstrate that the Operability Score allows a reliable prediction of outcome, thus giving indications and contraindications for surgery, and also for the surgical strategy. Moreover, we have explained why surgery had been refused in 9 additional cases during the same period. The causes of 8 fatalities out of 57 surgical cases are analyzed. These 57 cases represent a systematically explored series of the senior author; his experience is based upon 295 personal AVM cases (1958-1990).

[Cerebral microcirculation during increased intracranial pressure--assessment with reflectance photometry].

The cerebral microcirculation under increased intracranial pressure was evaluated by using reflectance photometric method. The values of tissue hemoglobin (IHb) and its oxygen saturation (ISO2) detected by this method were evaluated in cat brain tissue. The correlation between IHb and content of cortical hemoglobin subunits in vitro was high. High correlation between ISO2 and blood oxygen saturation in superior sagittal sinus was also noted in hypoxic hypoxia. Thus, the reflectance photometric method was revealed to be applicable for evaluation of regional hemoglobin content and oxygen saturation. Using this method the cerebral microcirculation was studied in an increased intracranial pressure model produced by injection of artificial CSF into the cisterna magna in cats. Regional cortical cerebral blood flow (CBF) was measured simultaneously by thermal diffusion method. During decrease of perfusion pressure down to 40 mmHg with preservation of CBF, compensatory increase of IHb was not observed, but IHb rather gradually decreased. The decrease of IHb would be due collapse of capacitance vessels by increased intracranial pressure. Cerebral ISO2 was stable as well as CBF. Less than 40 mmHg of perfusion pressure, ISO2 started to decrease in association with CBF and IHb. Since ISO2 seems to be closely related to the tissue oxygen extraction the change of ISO2 reflect the CBF and tissue cerebral oxygen metabolism. Present study suggest the evaluations of IHb and ISO2 were an useful monitoring indexes in various cerebral disorders.

Ischaemic brain oedema and xanthine-xanthine oxidase system.

The formation of oxygen-derived free radicals in cerebral ischaemia has been implicated in altering the BBB permeability, cause oedema and tissue damage. However little attention has been paid regarding the involvement of xanthine oxidase in the cerebral ischaemic events. Recently we demonstrated that cerebral ischaemia promotes the conversion of xanthine oxidase type D (nicotinamide adenine dinucleotide-dependent dehydrogenase) to type 0 (oxygen-dependent superoxide-producing oxidase). This investigation was concerned with elucidating the relationship between the conversion of xanthide oxidase and the duration of brain ischaemia. Four vessel-occlusion served as a model for the induction of cerebral ischaemia in rats. Xanthine oxidase was assayed by high pressure liquid chromatography using ultraviolet and electrochemical detection. The enzymatic conversion of xanthine oxidase from type D to type O increased with time from 7.6-15% during 5 min ischaemia to 27% and 36% at 15 min and 30 min after ischaemia, respectively. These results support the contention that xanthine oxidase may participate in free radical-induced ischaemic brain oedema.

Changes in xanthine oxidase in ischemic rat brain.

Xanthine oxidase activity in the rat brain was measured by means of high-performance liquid chromatography with electrochemical detection of uric acid. Cerebral ischemia was produced by a four-vessel occlusion method. In the control rat, the enzyme activity was 0.87 +/- 0.13 nmol/gm wet weight/min at 25 degrees C (mean +/- standard deviation), of which 92.4% was associated with the nicotinamide adenine dinucleotide (NAD)-dependent dehydrogenase form and only 7.6% with the oxygen-dependent superoxide-producing oxidase form. However, the ratio of the latter form increased to 43.7% after 30 minutes of global ischemia, despite the total xanthine oxidase activity remaining the same. Thus, it was revealed that uric acid can be synthesized in the rat brain and that cerebral ischemia induced the conversion of xanthine oxidase from an NAD-dependent dehydrogenase to an oxygen-dependent superoxide-producing oxidase. Although the xanthine oxidase pathway has been proposed as a source of oxygen-derived free radicals in various ischemic organs other than brain, the results of the present study suggest the involvement of the oxygen free radicals generated from this pathway in the pathogenesis of the ischemic injury of the rat brain.

Lipid peroxidation in focal cerebral ischemia.

To verify whether lipid peroxidation is associated with focal cerebral ischemia, a unilateral middle cerebral artery occlusion was carried out in rats. The concentrations of various endogenous antioxidants in the ischemic center were measured, including alpha-tocopherol and ubiquinones as lipid-soluble antioxidants and ascorbate as a water-soluble antioxidant. At 30 minutes after ischemia, alpha-tocopherol decreased to 79% of baseline, reduced ubiquinone-9 to 73%, ubiquinone-10 to 66%, and reduced ascorbate to 76%. Six hours after ischemia, alpha-tocopherol decreased to 63% and reached a plateau, whereas reduced ubiquinones and reduced ascorbate declined further to 16% and 10%, respectively, 12 hours after ischemia and then reached plateau levels. These results suggest functional and durational differences between antioxidants and lipid peroxidation in this ischemic model. Although the reciprocal increase in oxidized ubiquinones during ischemia was not observed, that of oxidized ascorbate was noted. The complementary antioxidant system between cytoplasmic and membranous components, the combination alpha-tocopherol/ascorbate, was estimated from the calculated consumption ratio of these antioxidants on the basis that the loss of these reduced antioxidants is due to neutralization of free radicals. This system is suggested to play an important role in the early ischemic period. Urate also increased during ischemia. The possible involvement of the xanthine-xanthine oxidase system in initiating free radical reactions in cerebral ischemia is also discussed.

Histochemical representation of regional ATP in the brain using a firefly luciferase-immobilized membrane in a multilayer film format.

The enzymatic bioluminescence of firefly luciferase has been used in sensitive pictorial assays of ATP. We describe a method using a membrane with immobilized luciferase in a multilayer film format for the histochemical representation of brain ATP content. The multilayer film consisted of a transparent support, a reagent layer, and a pigment layer. The reagent layer contained all necessary reagents, including immobilized luciferase. The pigment layer was effective for high image resolution. An unfixed slice of frozen brain 16 microns thick was placed on the film. The chemical energy of brain ATP was converted into luminescent energy in the reagent layer and the bioluminescence emitted was recorded photographically with high spatial resolution. A close linear relationship was obtained between the optical density of the bioluminescent images and logarithmic plots of the brain ATP content. With this film, the regional ATP content in fine anatomical structures of gerbil brains was clearly demonstrated in both physiological and pathological states.

[Lipid peroxidation and changes in xanthine oxidase in cerebral ischemia].

To verify the lipid peroxidation in the focal cerebral ischemia, the levels of alpha-tocopherol, ubiquinone and ascorbate were measured in the ischemic center in rats. The former two were endogeneous lipid soluble antioxidants and the last was a water soluble antioxidant. alpha-Tocopherol, reduced ubiquinone-9 and -10, and reduced ascorbate decreased to 79%, 73%, 66%, and 76% 0.5 hour after ischemia, respectively. alpha-Tocopherol decreased to 63% 6 hours after ischemia, and then reached a plateau, while reduced ubiquinones and reduced ascorbate declined further to 16% and 10% 12 hours after ischemia, respectively, and then reached plateau levels. These results suggest their functional and durational differences as antioxidants against lipid peroxidation in this ischemic model. Although the reciprocal increase in oxidized ubiquinones during ischemia was not observed, that in oxidized ascorbate was noted. The complementary antioxidant system between cytoplasmic and membranous components, the combination alpha-tocopherol/ascorbate, was estimated from the calculated consumption ratio of these antioxidants, assuming that the loss of these reduced antioxidants is due to neutralization of free radicals. This system was suggested to play an important role in an early ischemic period. Urate also markedly increased during ischemia. Therefore, xanthine oxidase activity was measured in rats both in normal brain and in ischemic brain induced by four-vessel occlusion method. In the control rat, the enzyme activity was 0.87 +/- 0.13 nmol/g wet brain/min at 25 degrees C (mean +/- S.D.): 92.4% was associated with the NAD-dependent dehydrogenase form and only 7.6% with the oxygen-dependent superoxide-producing oxidase form. However, the ratio of the latter form increased to 43.7% after 0.5 hour of global ischemia despite the same level in total xanthine oxidase activity. This result suggests the involvement of the oxygen free radicals generated from the xanthine oxidase pathway in the pathogenesis of the ischemic injury of the rat brain.

[Continuous lumbar subarachnoid pressure monitoring as an indicator of shunt operation for so-called normal pressure hydrocephalus].

Lumbar subarachnoid pressure (LSP) was continuously monitored via intrathecally introduced polyethylene catheter to select the patients for shunt operation. A total of seventy cases included so-called normal pressure hydrocephalus (NPH) secondary to subarachnoid hemorrhage (SAH; 34 cases), idiopathic NPH (17 cases), secondary NPH whose symptoms developed after operations for brain tumors, head injuries or meningitis (12 cases) and other intracranial diseases including pseudotumor cerebri or meningeal carcinomatosis, etc. (7 cases). Shunt operation was effective in 36 cases and not effective in 9 cases, while 25 cases were not shunted since LSP was not elevated or clinical manifestations were slight. Mean values of baseline pressure and maximum pressure in shunt effective group, shunt non-effective group and non-shunted group were 14.5, 12.7, 9.0 and 29.9, 25.0, 17.9 mmHg, respectively. Statistical difference was observed between shunt effective group and non-shunted group. Frequency of pressure waves was also significantly higher in shunt effective group than in non-shunted group. Above all, measurement of LSP was regarded as useful in idiopathic NPH. However, preoperative clinical symptoms had a closer relationship to shunt response than results of LSP in post SAH patients. Complication related to this monitoring was negligible except in one case of meningitis which was easily treated by administration of antibiotics. Follow-up study also justified our selection since no further deterioration was noted in non-shunted group. The present study indicates that measurement of LSP would be useful in selecting the patients who will benefit from shunting and in eliminating unnecessary shunt operations because this simple method is easily performed at bed side without perforating the skull.(ABSTRACT TRUNCATED AT 250 WORDS)

[Assessment of tissue and intracellular pH following cold-induced vasogenic brain edema--in vitro and in vivo study].

Acid-base balance is closely related to the brain function and various methods have been applied to estimate the intracellular, extracellular or tissue pH. Umbelliferone, a fluorescent pH indicator, has been used to study either intracellular or tissue pH. In the present study, umbelliferone was used for histochemically estimating the tissue pH in the rat brain. The pH nomograms were made from the difference between fluorescent intensities at 450 nm on both excitations at 370 nm and 340 nm at different tissue water contents and different umbelliferone concentrations. Linear correlations were noted under each condition but 0.125% w/v umbelliferone provided the best estimation of tissue pH because of the least influence of water contents. Using this concentration of umbelliferone, a histochemical study was done to estimate the sequential changes in tissue pH following cold-induced vasogenic brain edema in rats. The results revealed a clear delineation of brain edema and the mild alkalosis in the edematous tissue, which probably reflects the pH of leaked plasma fluid. While the pH in the cortex around the lesion was neutral in the histochemical study, it was acidic in the in vivo study. This discrepancy is probably due to the former indicating the tissue pH while the latter the intracellular pH. Thus, the alkalosis in the edema fluid and the intracellular acidosis in the cortex around the lesion were noted in the cold-induced vasogenic edema.

Reflectance spectrophotometric measurement of in vivo local oxygen consumption in the cerebral cortex.

A simple method was developed to measure in vivo local oxygen consumption quantitatively in the brain cortex. Reflectance spectra of tissue hemoglobin at the brain's surface were measured for assessment of both local tissue hemoglobin content and its oxygen saturation. Local oxygen consumption was calculated from the spectral changes of tissue hemoglobin during complete cessation of blood flow by compression of the cortical surface in the suprasylvian gyrus with the tip of an optic probe. This procedure was performed without any brain damage and only took approximately 5 s. The calculated local oxygen consumption during this short period of compression remained constant for a few seconds. Then, it decreased rapidly, although the local tissue hemoglobin was not completely deoxygenated. The value of local cerebral oxygen consumption obtained by this method was 3.02 +/- 0.61 mL O2/100 g brain/min; it was not influenced by the change in systemic blood pressure. The effect of pentobarbital on cerebral oxygen consumption was also studied. At the stage of burst and suppression on electrocorticogram, cerebral oxygen consumption decreased significantly (p less than 0.001) to 1.03 +/- 0.07 mL O2/100 g brain/min.

[Clinical validity of lumbar subarachnoid pressure measurement].

To evaluate the clinical usefulness for measuring lumbar subarachnoid pressure (LSP) as an index of intracranial pressure, the relation between LSP and epidural pressure (EDP) was studied by the cisternal saline infusion and bolus injection in 12 cats at the range of pressure up to 50 mmHg. In the steady state infusion (0.238 ml/min, 0.476 ml/min), the data from LSP and EDP were correlated very well and the LSP value was at least above 80-90% of EDP value at any pressure level. In the bolus injection (0.4 ml), the degree of pressure rise and the time course of both LSP and EDP were quite similar at any pressure level. However, the compliance calculated from the pressure change of LSP and EDP revealed to have a different tendency according to the baseline pressure level at bolus injection. Below 10 mmHg of EDP, the compliance calculated from LSP was usually higher that of EDP. This was considered due to the distensibility of spinal theca. But above 10 mmHg of EDP, the compliance of both LSP and EDP became almost equal and then gradually decreased as the elevation of baseline pressure at bolus injection. This was considered to be the result of disappearance of the distensible effect of spinal theca. In this study, two polyethylene tubes of different size (I. D. 0.45 mm, 0.58 mm) were used for spinal drainage tube to compare the pressure dumping effect of tube. However, on both tubes, the pulse pressure of LSP was usually smaller than that of EDP, with each having almost constant difference.(ABSTRACT TRUNCATED AT 250 WORDS)

[The sequential changes of energy metabolism following cold-induced brain edema--a histochemical study].

The changes of energy metabolism on vasogenic edema have been largely examined using biochemical quantitative assay. However, the relationship between the sequential changes and blood-brain barrier (BBB) breakdown is not well understood. In the present study, the sequential changes of energy metabolism and potassium in relation to BBB breakdown following the cold-induced brain edema were investigated histochemically. Adult male Wistar rats, weighing 200-250g, were anesthesized with pentobarbital and a burr hole was made in the left parietal region. For evaluating the breakdown of BBB, 2.5% Evans blue (EB) was injected 30 min. before injury, except in the 5 min. model in which it was injected at the time of cold injury. An iron-bar precooled in liquid N2 was placed over the surface for 30 seconds and they were frozen in situ in liquid N2 at 5 min., 2 hrs., 6 hrs., 12 hrs., and 24 hrs., after producing the lesion. The frozen brain was sectioned using a precooled saw in the coronal plane. The brain section was placed in liquid N2 bath and illuminated with 366 nm light (UV) from a 200 watt mercury lamp and Corning filter 5840. NADH fluorescence was recorded photographically through Corning filter 3387 and 5562. Regional ATP and potassium content were investigated histochemically in thin sections with luciferine-luciferase method and Macallum's technique, respectively. At 5 min. after cold injury, leakage of EB was limited within the lesion. Potassium and ATP were decreased in the lesion. NADH fluorescence was increased slightly in the cortex around the lesion.(ABSTRACT TRUNCATED AT 250 WORDS)

[Measurement and clinical significance of the posterior cranial fossa volume of patients with hemifacial spasm].

The etiology of hemifacial spasm had long been obscure until 1962 when Gardner proved that this hyperdysfunction of the facial nerve was caused by mechanical compression of the facial nerve by vascular structures in the posterior cranial fossa. In 1977, Jannetta proposed a specific location at the root entry zone of the facial nerve; this area has consequently been considered to be especially vulnerable to minor trauma such as vascular compression. In patients with hemifacial spasm, the posterior cranial fossa cavity is commonly found to be small or shallow on plain craniogram; this anatomical change in the skull is regarded as pathognomonic for the facial nerve hyperdysfunction. To make a quantitative analysis of the posterior cranial fossa volume in these patients, the following method was used. In the preliminary study, a dry human skull with an artificial "tentorium" made of thick paper was prepared to decide the fundamental plane for volume measurement by CT scan. This plane included attachments of posterior clinoid ligaments, superior petrosal veins and lateral sinuses. When this fundamental plane was projected to the lateral view on CT scan, it appeared to be almost identical to the line connecting the tip of posterior clinoid process to the internal occipital protuberance (the fundamental line). A horizontal CT scan for an intracranial volume measurement was performed in a parallel fashion to this fundamental line, with a 5 mm slice for the infratentorial and a 10 mm slice for the supratentorial area. The intracranial area of each horizontal slice was calculated by computed planimeter.(ABSTRACT TRUNCATED AT 250 WORDS)

[Three cases of Eagle's syndrome].

Recently microvascular decompression surgery has been performed for trigeminal neuralgia or glossopharyngeal neuralgia with remarkable success. In differential diagnosis of such neuralgia, a lot of atypical facial pain must be taken into consideration, one of which is so-called Eagle's syndrome. This syndrome is characterized by elongated styloid process or calcified stylohyoid ligament compressing the Vth and/or IXth cranial nerve. In the present paper we report three cases of Eagle's syndrome and discuss the mechanism, differential diagnosis and surgical treatment of the facial pain in this syndrome. The first case was a 40-year-old man. He complained of continuous dull pain on the right face. Sometimes he also suffered from radiating pain into the orbit and maxillary region. A-P and lateral projection of plain skull film showed elongated styloid process measuring about 4.5 cm in length. This process curved medially and was palpable in the tonsillar fossa. Above mentioned radiating pain was released by the injection of local anesthesic agent into the tonsillar fossa. From these findings, diagnosis of Eagle's syndrome was made. He was performed partial styloidectomy by transoral approach with complete relief of the facial pain. The second case was a 49-year-old woman. She complained of continuous or periodic pain that radiating from the right subauricular area to the right neck. Lateral view of plain skull film showed elongation of her right styloid process measuring about 4 cm in length. In the right tonsillar fossa, the elongated styloid process was palpable, compression of which induced radiating pain. By injection of anesthesic material into the right tonsillar fossa the pain disappeared temporarilly.(ABSTRACT TRUNCATED AT 250 WORDS)