The Strategy of Dural Arteriovenous Fistula with Isolated Sinus

We treated 7 cases of dural arteriovenous fistulas (dAVF) with isolated sinus by transvenous direct embolization.

The fistulas located in the transverse-sigmoid sinus in 5 cases, superior sagittal sinus in 1 case and transverse-sigmoid and superior sagittal sinus in 1 case.

The initial symptoms were generalized convulsion in 2 cases, disturbed consciousness in 1 case, tinnitus in 2 cases and transient ischemic attack in 2 cases. We performed sinus packing with coils in all cases following transarterial embolization.

All patients improved neurologically after the treatments and AVFs completely disappeared in all cases.

Silent cerebral infarction and cognitive function in middle-aged neurologically healthy subjects

We sought to clarify whether apparently silent cerebral infarcts and periventricular hyperintensities are associated with depressed cognitive function in middle-aged subjects. Subjects were 84 middle-aged neurologically normal adults who wished to undergo a screening examination of the brain. We performed magnetic resonance imaging (MRI) of the brain and neuropsychologic tests in all subjects. Silent cerebral infarcts and periventricular hyperintensities, respectively, were detected in 21 and 14 of 84 subjects. Mini-mental state (MMS) and Raven's colored progressive matrices (RCPM) scores were significantly lower in subjects with than without silent cerebral infarcts. By two-factor analysis of variance, MMS score was affected by silent cerebral infarcts or periventricular hyperintensities, with interactions between the two lesion types (P < 0.05). Silent cerebral infarcts may be an independent factor in the pathogenesis of intellectual dysfunction, but truly independent analysis is difficult because many subjects with silent cerebral infarcts also have periventricular hyperintensities.

Transcortical mixed aphasia due to cerebral infarction in left inferior frontal lobe and temporo-parietal lobe

We present a case of transcortical mixed aphasia caused by a cerebral embolism. A 77-year-old right-handed man was admitted to our hospital with speech disturbance and a right hemianopia. His spontaneous speech was remarkably reduced, and object naming, word fluency, comprehension, reading and writing were all severely disturbed. However, repetition of phonemes and sentences and reading aloud were fully preserved. Although magnetic resonance imaging (MRI) showed cerebral infarcts in the left frontal and parieto-occipital lobe which included the inferior frontal gyrus and angular gyrus, single photon emission CT revealed a wider area of low perfusion over the entire left hemisphere except for part of the left perisylvian language areas. The amytal (Wada) test, which was performed via the left internal carotid artery, revealed that the left hemisphere was dominant for language. Hence, it appears that transcortical mixed aphasia may be caused by the isolation of perisylvian speech areas, even if there is a lesion in the inferior frontal gyrus, due to disconnection from surrounding areas.

Transient crossed aphasia and persistent amnesia after right thalamic haemorrhage

A 45-year-old right-handed woman suffered transient aphasia and persistent amnesia after a right thalamic haemorrhage. This patient appeared to have crossed aphasia, although it disappeared within 8 weeks. It is noteworthy that the patient had a unilateral right thalamic lesion but exhibited both verbal and non-verbal memory impairment. Computed tomography and magnetic resonance imaging revealed cerebral haemorrhage in the right thalamus involving the ventral anterior nucleus, medioventral nucleus, mamillothalamic tract, internal medullary lamina, and mediodorsal nucleus. An amytal test was performed and suggested that the right hemisphere was dominant for language functions and the left hemisphere was dominant for visuospatial functions. Single photon emission CT revealed a low perfusion area only in the right thalamus. These findings suggest that the right hemisphere might be dominant for both verbal and non-verbal memory function in this patient, although visuospatial function was lateralized in the left hemisphere.

Memory impairment and spatial disorientation following a left retrosplenial lesion

We treated a patient in whom a left retrosplenial lesion resulted in memory impairment and spatial disorientation. A 31 year old, right handed man was admitted to our hospital after the sudden onset of headache. He was alert, attentive and cooperative, and showed no motor or sensory deficits. Although intelligence was preserved, memory was obviously deficient. The patient proceeded in wrong directions after he left his hospital room and subsequently his home. Neuroimaging revealed a subcortical hematoma in the left cingulate isthmus, while single-photon emission computed tomography demonstrated decreased perfusion in the splenium and left parietal lobe.

Haemorrhagic complication following percutaneous transluminal angioplasty for carotid stenosis

We report 2 cases with haemorrhagic complications following percutaneous transluminal angioplasty (PTA) for carotid stenosis. Computed tomography (CT) scanning of these cases demonstrated diffuse subarachnoid haemorrhage in 1 case, and intracerebral haemorrhage in the other case on the next day after PTA. In the latter case, we measured cerebral blood flow velocity and mean transit time with transcranial doppler (TCD) and dynamic CT scan, which demonstrated remarkable increases in the blood flow velocity and peak height, respectively. From these results, postoperative hyperperfusion was suggested to have caused haemorrhagic complications.

Interhemispheric neuroepithelial cyst associated with agenesis of the corpus callosum. A case report and review of the literature

This report describes a neonatal case in whom a large interhemispheric cyst associated with agenesis of the corpus callosum was revealed by fetal ultrasonography and demonstrated by MRI to be multilobulated. Endoscopic fenestration of cysts was initially designed in view of the development of the patient's brain and surgical invasiveness. One year later, when motor paresis of the left arm and progressive enlargement of the cyst on MRI were revealed, open surgery was performed. The histological diagnosis was a neuroepithelial cyst with the feature of choroid plexus epithelia. The clinicopathological features of interhemispheric epithelial cysts associated with agenesis of the corpus callosum are reviewed in the light of differential diagnosis and therapeutic considerations.

[Dural arteriovenous fistula at the cranio-cervical junction presenting transient ischemic attack: a case report]

A 58-year-old male was admitted to our hospital because of repeated transient ischemic attack of right hemiparesis and speech disturbance. A CT scan did not demonstrate any remarkable findings. No significant cerebral arterial stenosis or occlusion was found on angiography. However, dural arteriovenous fistula fed by the radiculo-meningeal artery was found at the cranio-cervical junction on left vertebral angiography. The shunt flow from the arteriovenous fistula drained into the superior petrosal sinus and sigmoid sinus in a retrograde fashion. On the angiographic findings when his transient ischemic attack (TIA) had disappeared, the venous drainage had returned to its normal fashion. Venous hypertension around the brain stem was supposed to have caused the transient ischemic attack in this case. We performed coagulation of the draining vein and fistula surgically. After surgery, the patient's TIA completely disappeared. We report the first case of dural arteriovenous fistula at the cranio-cervical junction presenting transient ischemic attack.

Transcortical sensory aphasia due to a left frontal subcortical haemorrhage

A case of transcortical sensory aphasia caused by a cerebral haemorrhage in the left frontal lobe is presented. A 72-year-old right-handed woman was admitted to the hospital, with a history of acute onset of speech disturbance and headache. On initial assessment, her spontaneous speech was fluent. She had no difficulty initiating speech, articulated normally, and did not exhibit logorrhea. Her ability to repeat phonemes and short sentences (5-6 words) was fully preserved, however she had severe difficulty with visual recognition of words, and with aural comprehension at the word level, although she was able to read words aloud. Computed tomography and magnetic resonance imaging showed cerebral haemorrhage in the left frontal lobe, involving the superior and middle frontal gyrus. Single photon emission CT revealed a wider area of low perfusion over the entire left frontal lobe, including the superior, middle and inferior frontal gyrus. The aphasia symptoms, mainly poor comprehension, disappeared quickly several weeks after the event. This may have been due to a reduction in the size of the haematoma and a resolution of the oedema around the haematoma. Clinically, the transcortical sensory aphasia in this case was indistinguishable from that caused by damage to the posterior language areas. Further case reports of transcortical sensory aphasia associated with frontal lobe lesions would help to confirm whether a relatively rapid recovery is characteristic in cases such as this.

[Construct validity of a new computer-assisted cognitive assessment battery in normal adults]

A computer-assisted battery for neuropsychological tests (CNT) has been designed to screen adults for cognitive impairment. The aim of this study was to gather evidence for the construct validity of CNT and also investigate the relationship between CNT and conventional neuropsychological tests. Subjects were 45 healthy adults (21 men and 24 women), who ranged in age from 20 to 70 years (mean = 33.5, SD = 1.9) with no history of substance abuse, or of psychotic or neurological disorders. The CNT in our study consists of six subtests designed to assess various components of driving, such as digit span, visual scanning, visual and verbal memory, complex reaction time, and vigilance. Mini-mental state test, Kana-hiroi test, word fluency, the auditory-verbal learning test and Raven's colored progressive matrices were also performed as conventional neuropsychological tests. Results showed there were high correlations between each CNT subtests and conventional neuropsychological tests. A factor analysis (with varimax rotation) identified 4 factors with eigen values greater than 1, which accounted for over 70% of the variance. CNT was able to estimate each factor related to cognitive function such as learning and memory, attention, judgment, and visual scanning selectively. CNT may thus be a useful tool for detection of cognitive impairment, although this test has important limitations. Broader applications of these tests will require extensive population-based validation.

[Thoracic arachnoid cyst presenting incomplete features of Brown-Séquard syndrome: a case report]

Spinal intradural arachnoid cyst presenting incomplete features of Brown-Séquard syndrome is very rare. Only 6 cases have been reported. We report one in a thoracic lesion. A 42-year-old man noticed thermohypesthesia in his right leg, and monoparesis in his left leg. On admission, he presented incomplete features of Brown-Séquard syndrome below the Th7 level. MRI showed the spinal cord to be displaced antero-laterally to the right at Th6-7 level. Myelography and CT myelography failed to show the cyst wall, but an arachnoid cyst was totally removed with T5-8 osteoplastic laminotomy. Sensory disturbance has not changed postoperatively, but motor weakness in his left leg recovered within one month after the operation. No cystic lesion has been detected by MRI during the ten months since the operation. We investigated all seven cases in the literature including our case which showed incomplete features of Brown-Séquard syndrome. As regards to the location of the cyst, all cases were at the mid-thoracic level. And four cases were at the midline. These results suggest that the mechanism of Brown-Séquard syndrome associated with spinal arachnoid cyst may be related not only to the laterality of the lesion but also to the asymmetrical circulation in the watershed area.

[A case of agraphia due to cerebral infarction in the left parietal lobe]

A case of agraphia due to cerebral infarction in the left parietal lobe was reported. A 63-year-old right-handed man was admitted to our hospital with writing disturbance. His spontaneous speech was fluent, and object naming, word fluency, repetition, verbal comprehension, and reading were fully preserved. However, his writing was slow and required effort. He showed hesitation in spontaneous writing and dictation. His power to copy was better than his power to write spontaneously or to take dictation, but he had some difficulty in copying letters and complex figures. The patient showed abnormal sequences of strokes and completed his strokes by piecing out of several fragments. CT scan and MRI showed a cerebral infarction in the left parietal lobe which included the superior parietal lobule. The amytal (Wada) test, which was performed via the left internal carotid artery, revealed that the left hemisphere was dominant for language. The characteristics of his agraphia much more closely resembled "apractic agraphia", as reported by Alexander et al (1992), than spatial agraphia or pure agraphia. Agraphia in this patient might result partially from the loss or unavailability of the memory of motor patterns necessary for writing letters.

[Distribution of Candida species and mutans streptococci related to oral conditions in elderly persons]

The purpose of this investigation was to find the relationship between the occurrence of Candida species and mutans streptococci at 7 sites (saliva, tongue, mucosa, teeth, clasp, external, and mucosal denture surfaces) in the mouth of 97 elderly persons (males: 43, age: 76.4 +/- 6.7 years; females: 54, age: 75.0 +/- 6.6 years). Among the subjects, there were complete denture wearers (n = 20), partial denture wearers (n = 45), and non-denture wearers (n = 32). Candida species were more significantly (p < 0.001) predominant in complete and partial denture wearers (80% each) than in non-denture (18.8%) wearers. The presence of Candida was highest on the mucosal denture surfaces followed by clasp, tongue, and remaining teeth in that order. Positive correlation were significantly found between the CFU numbers of Candida species and mutans streptococci present on the external surfaces (p < 0.001), natural teeth (p < 0.001), clasp (p < 0.01), and saliva (p < 0.05). A negative correlation (r = -0.503; p < 0.001) was found between the number of teeth and the CFU numbers of Candida species. Moreover, the CFU numbers of both groups of microorganisms also increased in 80-year-old and over persons. Candida species were most predominantly found in persons with poor oral and denture cleanliness.

Impairment of short-term memory in left hemispheric traumatic brain injuries

We report on two patients with traumatic lesions in the temporal and parietal lobes who demonstrated disturbances of short-term memory (STM) following improvement on the aphasia. Patient 1 was a 66-year-old right-handed man who presented to our hospital with a cerebral contusion. One admission we observed a Wernicke's aphasia with paraphasic jargon in this patient that resolved within 8 weeks. Patient 2 was a 35-year-old right-handed woman, with an acute subdural haematoma and a cerebral contusion, who underwent craniotomy and evacuation of the haematoma. In this patient we noted a transient Wernicke's aphasia following the operation that improved within 3 months. Linguistically, the aphasia observed in each of these two patients was not a typical conduction aphasia because of the absence of paraphasia, and impairment of comprehension was unclear despite a decrease in performance on repetition tasks. Both verbal and non-verbal tasks suggested an impairment in STM. These findings suggest that involvement of the left hemisphere may cause disturbances in both verbal and non-verbal STM.

[Syringomyelia appearing in a short term after brain abscess]

We describe a rare case of syringomyelia that developed within only 4 months after the cure of the focal cerebritis and abscess. An 18-year-old man who had suffered from meningitis and brain abscess 1.5 years before, presented with pain and sensory disturbance in his left shoulder. Magnetic resonance image (MRI) showed a syrinx formation extending from the upper cervical to the lower thoracic cord. Investigation by MRI during the course of the brain abscess had the appearance of posterior cerebellar arachnoid cyst 3 months after the onset of brain abscess and syrinx developed within 9 months. After posterior fossa decompression and reopening of the Magendie's foramen, his symptom and MRI abnormality improved after one month. In contrast to reported cases of syringomyelia following cerebritis, syrinx formation in our case appeared in relatively a short time. We speculated that basal arachnoiditis and the formation of posterior cerebellar arachnoid cyst caused syrinx formation in a short term after cerebritis.

[The effect on higher cortical dysfunction of percutaneous transluminal angioplasty for internal carotid artery stenosis]

Seven patients with internal carotid artery (ICA) stenosis with higher cortical dysfunction due to hemodynamic ischemia were treated by percutaneous transluminal angioplasty (PTA). The patients ranged from 49 to 71 years of age, and included five males and two females. Neuropsychological tests were evaluated before and after PTA. Higher cortical dysfunction improved in all cases after PTA. It is concluded that PTA is effective to improve higher cortical dysfunction in patients who have ICA stenosis associated with hemodynamic compromise, if the ICA is satisfactorily dilated.

Unilateral spatial neglect due to a haemorrhagic contusion in the right frontal lobe

We report two cases of unilateral spatial neglect associated with an isolated right frontal lobe lesion. Case 1 was a 59-year-old, right-handed man, who developed a left hemiplegia, disorientation, and frontal lobe neglect associated with a haemorrhagic contusion following a head injury. Case 2 was a 55-year-old, right-handed man, who also developed disorientation and frontal lobe neglect secondary to a haemorrhagic contusion following a head injury. 99mTc HM-PAO SPECT revealed an isolated reduction in the regional cerebral blood flow (CBF) around the haematoma in the frontal lobe; blood flow to remaining parts of the brain was normal. Damage to the right frontal lobes of these patients was confirmed as being the cause of the unilateral spatial neglect in accordance with the results of CBF studies.

[A case of spinal dural arteriovenous fistula associated with normal pressure hydrocephalus]

A 62-year-old male presented with urinary incontinence, gait disturbance and dementia for 6 months. Neurological examination revealed severe paraparesis (1/5), sensory disturbance below Th10, neurogenic bladder and absence of patellar and achilles tendon reflexes. CT scan showed mild brain atrophy and symmetric ventriculomegaly with periventricular lucency. Magnetic resonance imaging (MRI) showed a linear flow void lesion on the dorsal surface on the back of his swollen lower spinal cord. Myelography showed a filling defect and flow disturbance of contrast medium in lower thoracic levels, suggesting the presence of adhesive arachnoiditis. Spinal angiography demonstrated a fistula formation between dural branches of bilateral L4 lumbar arteries and ventral spinal and radicular veins on the surface of the dura mater of L4/5 levels. Considering his past history of repeated lumbar puncture for tuberculous meningitis at the age of 22 years, a diagnosis of acquired spinal dural arteriovenous fistula probably due to repeated lumbar puncture was made. Fistulas were embolized with N-butyl cyanoacrylate. And normal pressure hydrocephalus was treated by ventriculoperitoneal shunt. Follow-up CT scans showed a decrease of the size of the ventricular system. Etiology of acquired spinal arteriovenous fistula has been reported. In the case, repeated lumbar puncture may be a possible cause of arteriovenous fistula in the lower spinal dura mater. However, the reason why it took so long to form a fistula after the lumbar puncture remains to be elucidated. We suggest that an increased protein concentration due to disturbance of cerebrospinal fluid flow might be a cause of normal pressure hydrocephalus (NPH).

[A morphological study of interactions of Candida albicans and Streptococcus mutans]

Denture stomatitis is caused mainly by infection of Candida albicans and Streptococcus mutans, the most predominant members of the bacterial flora on denture surfaces. The purpose of this study was to investigate the adhesion in vitro of C. albicans and of S. mutans to acrylic surfaces and their interactions. Concentrations of C. albicans and of S. mutans (mutational phase I and III in which activities of glucosyltransferases are higher and lower respectively) were of high levels (> or = 5.0 x 107 colony-forming-units per ml; CFU/ml). The colonies in brain-heart-infusion (BHI) broth added 5% sucrose incubated at 37 degrees C for 18 and 72 hours. Then the samples were dried and evaporated, and examined by S-700 and S-4100 SEM (HITACHI). It was found that S. mutans (mutational phase I) synthesized water-insoluble glucans concomitantly with the adhesion of both S. mutans and C. albicans to the acrylic surfaces. Also, adhesion of C. albicans, mediated by cell-to-cell interactions with S. mutans (especially mutational phase III), to the surfaces was observed.

[Effects on cognitive function and activities of daily living after stereotactic thalamotomy for Parkinson's disease]

Stereotactic thalamotomy was performed in ten patients with Parkinson's disease for the suppression of their tremor. After VL-thalamotomy, contralateral tremor and rigidity disappeared or was significantly reduced. Activities of daily living (ADL) measured by functional independence measure and Parkinson's disability score were improved postoperatively in all patients. There was significant improvement in anxiety index. However, other neuropsychological tests showed no significant change postoperatively. ADL improved after thalamotomy. It is concluded that stereotactic VL-thalamotomy is a useful treatment which improves ADL without cognitive dysfunction.

[Transcortical sensory aphasia in a patient with metastatic brain tumor in the left frontal lobe]

We reported a case of a 62-year-old right-handed woman who had transcortical sensory aphasia caused by a metastatic brain tumor in the left frontal lobe. She had mild right hemiparesis involving the face, without hyperactive tendon reflexes. She had neither sensory disturbance nor other cranial nerve deficits. Her spontaneous speech was fluent, and she sometimes had echolalia. Her object naming, word fluency, verbal comprehension and writing were severely disturbed. This contrasted with full preservation of repetition of phonemes and short sentences. Reading of words was preserved. CT scan revealed a subcortical lesion in the left superior frontal gyrus. Gd-enhanced MRI showed a ring-enhanced mass lesion in the frontal lobe outside of Broca's area. We thereby concluded that transcortical sensory aphasia may be caused by frontal lobe lesion independent of the perisylvian speech areas.

Synthesis and cardiovascular activity of phenylalkylamine derivatives. I. Potential specific bradycardic agents

A series of acyclic amide derivatives of N-(omega-aminoalkyl)-N-methylhomoveratrylamine was synthesized and evaluated for their bradycardic activity in isolated guinea pig right atria. Among these compounds, (E)-N-[3-[N'-[2-(3,4-dimethoxyphenyl)ethyl]-N'-methylamino]propyl]- 4-[3,4-(methylenedioxy)phenyl]-3-butenamide (35) was the most potent in vitro and was also found to show dose-dependent bradycardia without remarkable reduction of left ventricular dp/dtmax or mean aortic pressure in anesthetized dogs.

[Studies on caries of Ishibashi rat--III. Experimental caries in Ishibashi rat]

Dental caries was experimentally induced in the Ishibashi rats (ISR) by feeding them with conventional diets or with caries-producing diets, and the pattern and severity of their induced carious lesions were compared with those of the Sprague-Dawley rats (SD). Simultaneously, serum antibody titers against Streptococcus mutans and calcium and phosphorus concentration in the sera and in the femurs were compared between the ISR and SD. The results were as follows: 1. When judged by cavities, ISR showed a higher carious incidence and average number of cavities per one rat than the SD, whichever diet the rats were fed. 2. When judged by fissure caries observed on the thin sections of the teeth, both the carious incidence and average number of fissure lesions in the ISR were not always high compared with those in the SD, and there seemed to be a great variation of caries-susceptibility in the ISR. 3. Caries in the ISR seemed to be more progressive than that in the SD. 4. There were no differences in the serum antibody titers against the S. mutans between the ISR and SD. 5. No differences in the concentration of calcium and phosphorus in the sera and femurs were observed between the ISR and SD, whichever diet they were fed.

[Studies on caries of Ishibashi rat--I. Dental caries in Ishibashi rat]

Ishibashi rats (ISR), which have been demonstrated to be excellent experimental animals for congenital vertebral anomaly, are often observed to develop extensive dental caries even when maintained with the conventional diets instead of any caries-producing diets. In this study, dental caries produced in the ISR fed the conventional diets, commercial pellets, was examined and the location and severity of the lesions were compared with those of the albino rats fed the same diet. The results were as follows: 1. Although no caries was detected up to 100 days of age, 70-100% of the ISR of 101 days and over in age had carious teeth. In the albino rats, only 7-30% had carious teeth. 2. The severity of the carious lesions was much greater in the ISR than in the albino rats. 3. Only the mandibular molars were attacked by the dental caries, and the lesions occurred most frequently in the second fissure of the second mandibular molar both in the ISR and the albino rats. Extensive destruction of the crowns of the ISR second mandibular molars were observed in some specimens, but such destruction was not observed in the specimens of the albino rats. These results suggested that the ISR were susceptible to dental caries, and the development of the dental lesions of the ISR seemed to be rapid compared with that of the albino rats.

[Studies on caries of Ishibashi rat--II. Streptococcus mutans population in oral cavity]

Previously, it was demonstrated that extensive carious lesions occurred in the Ishibashi rats (ISR) while they were bred with conventional diets. In this study, specimens from the oral cavity of the ISR were examined for the presence of Streptococcus mutans, and its occurrence and population were compared with those of the Wistar rats. The results were as follows: 1. S. mutans was first found in the mouth of the ISR when the first molars erupt. 2. The number of S. mutans (CFU on the gelatin agar) and its mean percentage of the total streptococci (CFU on the gelatin agar/CFU on the M-S agar) in the mouth of the ISR increased rapidly during the few days after weaning, and this increment was comparable to that of the Wistar rats fed caries-producing diets, 6PMV, after weaning. However, the population of the S. mutans remained low in the mouth of the Wistar rats fed conventional diets. 3. In the aged ISR, the number of S. mutans and its mean percentage of total streptococci were also much higher than in the aged Wistar rats. These data suggested that the ISR harboured increased the number of S. mutans strains in the oral cavity when compared with the Wistar rats.

Cystic arteriovenous malformation. A case report

The authors report on a rare case of arteriovenous malformation (AVM) associated with cyst formation. Only five similar cases have been reported. CT findings of the cyst are divided into two types: 1) slit-like low density and 2) round one. Three patients showing slit-like cysts had experienced sudden severe headaches, probably due to haemorrhage. In contrast, two patients showing round cystic lesions had not experienced such sudden headaches and they revealed a nodule in the cyst at surgery. These facts suggest that there may be two different mechanisms for cyst formation in AVM's: haemorrhage and exudation. Slit-like cysts may result from old haemorrhage from the AVM nidus. Round cystic lesions may be due to exudation from the AVM nidus.

[Intracranially recorded trigeminal compound action potential: with special reference to trigeminal neuralgia]

To elucidate the origin of the early component of the trigeminal sensory evoked potential (TSEP) we reported in 1985, we recorded evoked potentials on the trigeminal root and the brain stem surface intracranially when suboccipital craniectomy was done for exploration of the C-P angle. Patients consisted of 4 who had idiopathic trigeminal neuralgia with microvascular decompression, 1 with glossopharyngeal neuralgia who also had microvascular decompression of the left glossopharyngeal nerve, and 5 patients with different tumors, specifically, Meckel's cave meningioma, two epidermoid cysts of the cerebello-pontine angle, an acoustic neurinoma and a trigeminal neurinoma. Among the tumor patients, all but the one with acoustic neurinoma had trigeminal neuralgia. So altogether, there were 8 patients with trigeminal neuralgia. Constant electrical current was applied to the lower and upper lip for stimulation of the second and third division, respectively. In some cases the electrical current was applied percutaneously to the infraorbital nerve for the stimulation of the second division. The supraorbital nerve was stimulated percutaneously for stimulation of the first division. To record and analyze the potentials, Evomatic 8000 (Dantec) was used. Analysis time was from 10 to 100 msec and the stimulation was repeated 200 times. Trigeminal compound action potential (TCAP) was recorded on the trigeminal nerve just distal to the entrance point to the pons. For the recording TCAP, a gold ball electrode of 1 mm diameter was used with indifferent needle electrode in the neck muscle. In some cases a digital filter was applied to the recorded TCAP. The TCAP evoked by stimulation of the second division had 2 to 8 positive potentials in 8 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

[Arteriovenous malformation associated with cyst. Case report]

The authors present the fifth reported case of arteriovenous malformation (AVM) associated with cyst formation. Among these five cases, computed tomography has demonstrated two types of cyst: round, and slit-like with low density. The three patients with slit-like cysts experienced sudden, severe headache, probably due to hemorrhage. The two patients with round cystic lesions did not have sudden headache, and at surgery the cysts were found to contain a mural nodule. These facts suggest that there may be two different mechanisms of cyst formation in the vicinity of an AVM: hemorrhage (slit-like cysts) and exudation (round cysts).

Stereotactic operation for brain abscess

Stereotactic management of brain abscess (stereotactic aspiration with external drainage) was performed in 14 patients. Fifteen abscesses in 14 patients were successfully aspirated by this method. After aspiration of the abscess, all patients underwent external drainage for an average of 14.5 days. No complications during aspiration or during external drainage (such as bleeding or infection, respectively) were encountered in our series. Ten out of 14 patients (71.4%) showed excellent prognosis, and 3 of 14 (21.4%) showed good outcome. Only one patient died after the operation, but this was due to lung cancer. Our operative results are quite satisfactory in comparison with operative results reported by other authors.

[Multiple malignant intracerebral schwannomas in von Recklinghausen's disease--report of a case]

Intracerebral schwannoma is very rare, and only nine cases of solitary intracerebral schwannoma have been reported since the first description by Gibson et al, in 1966. This report is the first case of multiple intracerebral schwannomas in Japan. Intracranial extracerebral schwannomas in von Recklinghausen's disease are sometimes encountered, but intracerebral ones have not been discovered. A case of multiple intracerebral schwannomas associated with von Recklinghausen's disease is reported in a 23-year-old male. He had been healthy until January 1979 when he was pointed out an abnormal shadow on chest roentgenogram. Although thoracic tumor revealed schwannoma in histological examination of surgical specimen, it transformed to malignant one during next 15 months. In July 1980, he complained of severe headache, vertigo, nausea and vomiting, and bilateral papilledema was proved. He was admitted to our clinic on August 8, 1980. Two large intracerebellar and four intracerebral tumors were revealed by computed tomography (CT). Angiography demonstrated avascular masses. The cerebellar tumors were totally extirpated on August 12, 1980. Histological diagnosis of the removed tumors approved malignant schwannoma, but their correlation to the chest tumor was unclear. Follow-up CT scans demonstrated that the supratentorial tumors increased in size during about three months. The chest tumor also increases in size. He died on November 12, 1980, but autopsy was not done. Pathogenesis of intracerebral schwannomas in this case is controversial, and we suggest that it is (1) multiple schwannomas in von Recklinghausen's disease with malignant transformation, or (2) metastasis from the chest tumor. But the conclusion remains unclear.

Bilateral aneurysm formation developing from junctional dilatation (infundibulum) of the posterior communicating arteries. Case report

✓ The authors report a case in which bilateral aneurysms developed from junctional dilatations of the posterior communicating arteries. A 7-year follow-up study of this case strongly suggested that an infundibulum can develop into a true aneurysm. After reviewing seven cases in the literature, the authors conclude that junctional dilatations, especially in young women with a history of aneurysmal rupture, should be carefully followed by angiography.