[Objective evaluation of selective peripheral denervation for spasmodic torticollis].

The authors evaluated the results of selective peripheral denervation (SPD) of posterior rami of the cervical spinal nerves and/or the accessory nerve for spasmodic torticollis. Five patients underwent seven operations in total and the results were evaluated with the modified Tsui's score which was used in the clinical trial of botulinum toxin (BTX) for torticollis in Japan. The preoperative score was 10.8 +/- 2.2 (mean +/- S.D.) and the postoperative score was 1.4 +/- 1.7. The score changes indicated the effects of the operation as "excellent" in four cases and "good" in one case. These results indicate that SPD is superior to BTX in terms of control of symptoms in spasmodic torticollis. After the initial operation, however, two patients showed the so-called "mole-hitting game phenomenon" in which normal muscles develop abnormal contraction after denervation of abnormal muscles. This forced us to perform the second operations. Although this phenomenon was first described in botulinum toxin treatment, this is probably the first report in surgically denervated cases.

Pleomorphic xanthoastrocytoma with neurofibromatosis type 1: case report.

The authors report a case of pleomorphic xanthoastrocytoma (PXA) with neurofibromatosis type 1 (NF-1). A 21-year-old woman, noted to have had a number of café au lait spots since birth, presented with the chief complaint of headache. Neuroradiological studies revealed a cystic tumor of the left parietal lobe. Surgical treatment was performed. The tumor was located on the surface of the parietal lobe with the formation of cysts. Light, electron microscopic, and immunohistochemical examination showed the characteristics of typical PXA. This is the second reported case of NF-1 associated with PXA.

A new approach to the control of central deafferentation pain--spinal intrathecal baclofen.

We investigated the short-term effects of an intrathecal bolus injection of baclofen on central pain due to stroke or spinal cord injury. Pain relief was obtained in 64% of the patients. The effects developed 1-2 hours after the injection and continued for 10-24 hours. Both spinal segmental and supraspinal mechanisms may be involved in the production of baclofen-analgesia.

A new approach to control central deafferentation pain: spinal intrathecal baclofen.

Baclofen, an agonist of the gamma-aminobutyric acid (GABA) receptor, has antinociceptive effects, and its intrathecal administration reduces allodynic responses in animal models of neurogenic central pain. Such experimental studies lead to the hypothesis that neurogenic pain may be induced in part by functional abnormalities in spinal GABAergic systems. However, whether a GABAergic system is actually involved in human central pain is unknown. The authors investigated the effect of an intrathecal bolus injection of baclofen in 14 patients with central pain due to a stroke or spinal cord injury. Nine reported substantial pain relief they had never experienced previously. The effect appeared 1-2 h after the injection and persisted for 10-24 h. Allodynia and hyperalgesia, if present, were relieved as well. Pinprick and light touch sensations did not change in nonaffected regions. The results indicate that dysfunction of spinal GABAergic systems plays a role in the clinical expression of central pain. In clinical situations, continuous intrathecal infusion of baclofen seems feasible for relief of central pain.

An image-guided stereotactic system for neurosurgical operations.

A new simulation system utilizing digital images (CT/MRI/SPECT) and an ultrasound/laser navigation system has been developed for image-guided surgery. Preoperative CT/MRI imaging does not always indicate the actual location of the lesion during intracranial operation, because the lesion may be displaced or distorted by operative procedures or CSF flowout. The authors developed an image integration system including an intraoperative ultrasonogram, which provides accurate information not only on the location of the deep-seated lesions but also surrounding anatomical structures during operation. The rationale of the system is to coordinate the three-dimensional axes of each image with the aid of a stereotactic subframe. Our simulation system has two ways. One simulation system works on a SUN workstation. At the preoperative simulation study: the entry point on the brain surface and the access route to the lesion are decided on from the three-dimensional CT/MRI images on the computer display. Then the configuration of the lesion from the operative view is displayed as an expected ultrasound image by reconstructing the CT and/or SPECT image. Another simulation system (HyperCAS) works on the HyperCard of a MacIntosh. The target point, the entry point and the trajectory are decided on and the three-dimensional location of these points is measured from serial CT images on the LCD display. At the time of operation, stereotactic craniotomy is performed using the laser navigator. The extent of the lesion at every depth in the surgical process is predicted from these images, and the access route to the lesion is easily corrected with the intraoperative ultrasound navigator.(ABSTRACT TRUNCATED AT 250 WORDS)

Stereotactic mesencephalotomy for pain relief. A plea for stereotactic surgery.

Rostral mesencephalic reticulotomy (RMR) for pain relief was performed in 34 patients with intractable pain. Most of these patients have been followed for a long period of time postoperatively, the longest follow-up period being 11 years. Contrary to the commonly prevailed bias in the past that mesencephalotomy may be a surgical intervention with potential risk, these patients of RMR have continued to substantial improvement postoperatively in terms of their preoperative intractable painful dysesthesia after a long period of time. The results of pain relief for denervation pain as well as for nondenervation pain are surprisingly good even after unilateral procedures. There was no operative mortality. Postoperative disturbance of ocular motility has been reduced. RMR has its scientific basis in that the medial part of the reticular formation rather than the classical lateral spinothalamic tract has more significance in the central conduction of nociceptive impulses through the midbrain level, which was verified by intraoperative neuronal recording with a tungsten microelectrode. The present report emphasizes that stereotactic mesencephalotomy, if performed meticulously and precisely, is a safe surgical procedure for pain relief. Results of MRI and sensory manifestations of a patient 11 years after RMR are also presented.

[CT-guided stereotactic surgery of brain abscess].

Seven patients with brain abscess underwent CT-guided stereotactic aspiration using Iseki's stereotactic apparatus. Three of them were under the age of fifteen and four were older than thirty. The lesions were single and round in four cases, multilobular in two and multiple in one patient. Operations were performed after systemic administration of antibiotics for more than two weeks and after capsule formation was confirmed on CTs. Preoperative volume of the abscesses was estimated from CTs. The target point chosen was the center of the ring of the largest diameter in the enhanced lesion. Abscess was aspirated under monitoring with intraoperative CT scan. No continuous drainage was performed and no antibiotics were given directly into the abscess cavity. In all cases the center of the abscess was punctured with a single trial. Average volume of the preoperative brain abscesses was 18.8ml. Aspirated volume at the time of the operation averaged 16.9ml and all the abscesses decreased to unmeasurable size on CTs. In five of seven patients abscesses were cured after a single aspiration, and in one case after the second operation. One case required extirpation of the lesion. During the follow-up period of four months to five and a half years six patients showed no recurrence. One patient died of unrelated cause four and a half years after the operation. No operative complication was noted. There was no operative morbidity or mortality. Using a CT guided stereotactic method, brain abscess is punctured so accurately, regardless of its location and size, that damage to the surrounding brain during operation can be minimized. Therefore it is highly possible to aspirate abscesses completely.(ABSTRACT TRUNCATED AT 250 WORDS)

Bilateral versus unilateral percutaneous high cervical cordotomy as a surgical method of pain relief.

The present report is concerned with the results of bilateral percutaneous high cervical cordotomy (60 patients) compared with those of unilateral cordotomy (161 patients). The result of pain relief is classified into 4 grades based on Hitchcock's criteria; grade 1: complete pain relief, grade 2: almost complete pain relief with slight residual pain, grade 3: persisting pain, but tolerable, grade 4: persisting pain, untolerable. In cases of bilateral cordotomy (60 patients), 76% of the cases showed grade 1, 19% being grade 2, 3% being grade 3 and 2% being grade 4. On the contrary, the unilateral cordotomy (161 patients) showed less impressive results, particularly in grade 1, namely, grade 1 being 64%, grade 2 being 18%, grade 3 being 14% and grade 4 being 4%. Clinically acceptable results (grade 1 plus grade 2) were, therefore, obtained in bilateral cordotomy (95%) as compared with unilateral cordotomy (82%). The difference in pain relief between bilateral and unilateral procedure observed in the present investigation is contrary to that reported previously by others. The possible explanation for less impressive result in regard to grade 1 of unilateral cordotomy is that unilateral cordotomy was performed in this series to alleviate the major side of patient's pain, followed by latent pain on the other side postoperatively, which is not uncommon phenomenon in cancer pain. Whereas all of the bilateral cordotomies were done either for midline pain or bilateral pain, unilateral cordotomy gave satisfactory pain relief in some cases of midline pain. Midline pain, therefore, does not necessarily require bilateral cordotomies from a clinical point of view.(ABSTRACT TRUNCATED AT 250 WORDS)

An ultrasound-guided stereotactic apparatus for intracranial mass lesions.

One of disadvantages of conventional stereotactic operation for intracranial mass lesions is that it is basically a blind procedure even if the operation is performed in a gantry of a CT scan. High resolution ultrasound image gives real-time information on intracranial pathology such as bleeding, remaining cyst fluid or haematoma. The authors report an ultrasound guided stereotactic apparatus which gives real-time images of the lesion during operation.

[A new apparatus using the Micro Ultra-Sonic Aspirator (MUSA) system for microneurosurgery].

Matsumoto was the first to present the NIIC UltraSonic Aspirator for CT guided stereotactic aspiration of intracerebral hematoma. Based on the NIIC Aspirator, the authors have developed a useful tool for microsurgery by adapting conventional ultrasonic aspirators. This was done by making the aspirator lighter and more handy for use during microsurgical procedures. A newly devised apparatus using the Micro Ultra-Sonic Aspirator (MUSA) was applied clinically to surgical treatment for brain tumors, arterio-venous malformations (AVMs) and intracerebral hematomas. Using the MUSA system, it became easier to remove successfully tumorous mass and the nidus of AVM, because it minimized the risk of injury to the normal structures such as the surrounding brain tissue, vascular systems and the cranial nerves.

[Identification of location of electrode tip during percutaneous retrogasserian glycerol injection (PRGI) with blink reflexes elicited by direct stimulation of trigeminal complex (DBR)].

In order to identify the location of the electrode tip during percutaneous retrogasserian glycerol injection (PRGI), the blink reflex (DBR) following direct stimulation of the trigeminal complex (the gasserian ganglion, trigeminal rootlets, or the 3rd division of the trigeminal nerve) was obtained from 6 patients with trigeminal neuralgia. 1) The waveform of the DBR was very similar to that of the blink reflex (BR) elicited by percutaneous stimulation of the 1st division of the trigeminal nerve. However, the latency of early reflex (R1) as well as late reflex (R2) of the DBR was approximately 2 msec shorter than that of the conventional BR. 2) When the electrode tip was introduced into the gasserian ganglion, the DBR showed the largest response under the same recording condition, whereas the DBR was not recorded when the tip of the electrode was placed into either the arachnoid space or the subdural space. The each DBR response, however, showed the same configuration when the electrode tip was situated at the territory of the 1st, 2nd or 3rd division of the trigeminal nerve within the gasserian ganglion or the trigeminal cistern. 3) The DBR always appeared under the anesthesia with the intravenous administration of 10 mg diazepam and 30 mg pentazocine. 4) Based on the present study, the DBR proved to be an usuful parameter in determining whether the electrode tip is introduced into the trigeminal complex or not, particularly in the case of patients having no reliable sensory response to electrical stimulation.

[EEG topographic changes of brain abscesses in children].

EEG topography was investigated before and after surgical treatment in 4 patients with brain abscess aged from 5 to 13 years. According to the recording technique designed by Matsuoka and Ueno, the recorded EEG for each 5 seconds was analyzed to obtain square roots of power spectra for each band of delta (2-3.8 Hz), theta (4-7.8 Hz) and alpha (8-12.8 Hz) which were then added for the 60-seconds duration of each trial. After that, numerical matrix presenting the topographic distribution of spectral energy of each band were constructed and displayed as color images. In addition, the EEG topographies of brain abscesses were compared with the CT scans simultaneously obtained. In all of four cases before surgical treatment of the brain abscess, the location of the focal delta wave on the EEG topography was more closely related to the site of brain abscess comparing with its correlation between the location of the delta focus on the conventional EEG and the site of brain abscess. In contrast, as for the theta wave, there was no prominent correlation to the site of the brain abscess. In the early stage of 10-15 days after aspiration of the brain abscess, the most characteristic change of the EEG topography was an approximately 25% reduction of the maximum equivalent voltage of delta band with associated disappearance of the sharply located focal delta wave being noted before aspiration.(ABSTRACT TRUNCATED AT 250 WORDS)

[CT-guided stereotactic brachytherapy in deep-seated malignant gliomas--interstitial irradiation by double-catheter after-loading method].

CT-guided stereotactic brachytherapy has been performed for the deep-seated malignant gliomas using the double-catheter after-loading method. The catheter system consists of two coaxial polyethylene tubes with closed tips. The outer catheter is 3.0 mm in outer diameter and 2.4 mm in inner diameter. The inner catheter is 2.0 mm in outside diameter and 1.4 mm in inside diameter, and contains the radioactive sources. Localization of the target volume is determined by the preoperative findings of computed tomography (CT), magnetic resonance imaging (MRI), and cerebral angiography. Dosimetry and dose planning are so finalized for the target volume as to be irradiated interstitially more than tumoricidal dose. After stereotactic biopsy of the deep-seated brain tumors, stereotactic implantation of the outer catheters is performed using Iseki Stereotactic System in the CT room. Burr holes had been previously opened in the operating room. The inner catheters containing nonradioactive sources (dummy sources) are inserted, and skull X-p is taken to confirm the position of the dummy sources, and to calculate the dosimetry by computer. The inner catheters are replaced with catheters containing radioactive sources (226Ra) in the irradiation room. 226Ra sources deliver at least 500 rads/day (approximately 20 rads/hr) to the target volume as interstitial irradiation. Two patients of malignant gliomas treated with this procedure were shown as representative cases. These patients underwent CT-guided stereotactic brachytherapy as "boost" combined with conventional external irradiation.(ABSTRACT TRUNCATED AT 250 WORDS)

Short latency somatosensory-evoked potentials--direct recording from the human midbrain and thalamus.

Short latency somatosensory-evoked potentials were recorded from the human thalamus and the midbrain during stereotactic operations. Several subcomponents were recognized on the peak of N18. These were recorded with maximal amplitude at the border between the caudal portion of the thalamus and the rostral midbrain. Two positive-negative responses, not previously shown, were observed between P14 and N18. These responses were prominent in the rostral midbrain. These findings indicate that the ascending phase of N18, and the N18 itself, are the compound potential generated in the mesodiencephalic junction.

Surgical treatment of hypertensive intracerebral haematoma by CT-guided stereotactic surgery.

Ninety consecutive cases of hypertensive intracerebral haematoma were treated with CT guided stereotactic evacuation. The patients were composed of 61 males and 29 females, ranging from 42 to 87 years old. The location of haematoma was either in the putamen (59 cases) or in the thalamus (31 cases). The average volume of the evacuated haematoma was 21.4 ml in the putaminal haematoma and 14.0 ml in the thalamic haematoma. Postoperative follow-up study in 46 patients showed good recovery of neurological deficits both in putaminal and thalamic group. Criteria of surgical indication of CT-guided stereotactic evaluation of intracerebral haematoma were advocated based on the author's clinical experience.

[Chronological changes in the blink reflex and MRI in a patient with lateral medullary infarction].

Recently, the brainstem pathways of bilateral late reflexes (R2) of electrically elicited blink reflex have been well established. An afferent delay or block of the late reflexes is closely related to a lesion of the lateral medullary portion. The chronological alteration of blink reflex (BR) was studied to compare with radiological abnormalities on MRI in a patient with lateral medullary infarction on the right side. A diagnosis of Wallenberg syndrome was made clinically and location of the lesion was identified in detail by MRI. The infarcted region which was well demonstrated as an increased intensity area on SE images obtained 52 days after the onset of symptoms was much smaller than that on SE as well as on IR image 21 days after the onset of symptoms. Therefore, it was concluded that more than half of the increased intensity area on the SE images obtained 21 days after the onset of symptoms recovered from the condition of being extremely damaged by ischemia on the right lateral medullary portion in this patient. On the other hand, in the initial BR 26 days after the onset of symptoms, the late reflexes (R2) were consistently absent bilaterally when the affected side (right) was stimulated and normal when the normal side (left) was stimulated. This type of BR abnormality is compatible with an afferent block of late reflexes (R2). The early reflex (R1) was normal on either side. Whereas in the second BR at 55 days after the onset of symptoms, the late reflexes turned to be normal in latency when the right side was stimulated.(ABSTRACT TRUNCATED AT 250 WORDS)

[A new treatment of hypertensive intracerebral hematoma--a follow-up study on 46 patients with hematoma treated by CT guided stereotactic method].

During the last 2 years, 46 cases of hypertensive intracerebral hemorrhage in the basal ganglia were treated by CT guided stereotactic aspiration and their outcome was evaluated in terms of the rate of hematoma removal, the change of consciousness level and the recovery of motor and sensory functions. They are aged from 45 to 79 years old, the average 56, and aspirated 1 to 24 days after the onset, two third of them being within 1 week. The whole procedure was done in the CT room under direct CT guidance and by one trial. In putaminal type hemorrhage, the removed hematoma volumes ranged from 9 to 48 ml, average being 23.7 ml, in thalamic type from 5 to 29 ml, average being 15.5 ml. The average rate of removal was 81.1% in 30 cases within 1 week. In most cases, preoperative consciousness was not severely disturbed, in putaminal type, 19 were alert or confused, 4 somnolent, 5 stuperous and in thalamic type, 6, 6, 3 respectively and 2 were semicomatous, one of them had herniation sign. In putaminal type all but 2 cases recovered to alert or confused state, the first one had postoperative bleeding and the other was already apallic preoperatively. In thalamic type, we lost 3 cases, 2 by gastrointestinal bleeding and 1 DIC, by rehemorrhage 2 months after the operation. All but one who was semicomatous preoperatively recovered to alertness. In motor function, some cases of the putaminal bleeding with intact internal capsule remained hemiplegic. On the other hand, most of the cases with partial destruction of the internal capsule on CT recovered well in both types of hematoma.(ABSTRACT TRUNCATED AT 250 WORDS)

[Significance probability mapping of brain electrical activity--its problem and specified z-statistic mapping].

Significance probability mapping (SPM) of brain electrical activity first described by Duffy et al. is useful tool for studying functional aspects of brain disease. Z-statistic SPM is able to identify the area of brain electrical activity deviated with statistic significance from the control group. The problem of this method is, however, that the nature of deviation, i.e., whether it is increase or decrease of electrical activity, can not be displayed. From this point of view, we attempted to use modified z-statistic method. Statistically deviated region and its nature can be clearly displayed on the same picture by analyzing EEG with this method. This method can be applied to SPM of evoked potentials. SPM is not yet complete method for the assessment of brain electrical activity, but there is much room for adopting other statistic method that is more suitable for the aim of the study. Functional aspects of the brain will be more readily clarified by the use of modified SPM and by combination with findings of CT scan, NMR and PET that can give morphological and metabolic information.