The authors report the results of a long-term follow-up study of the effects of the physiologically defined selective VIM (nucleus ventralis intermedius)-thalamotomy on tremor of Parkinson's disease in 27 patients and essential tremor in 16 patients. The follow-up period ranged from 3.25 to 10 years (mean 6.58 years). In 43 patients a total of 50 operations (including four bilateral operations and three reoperations) were carried out. The early (2 to 4 weeks after surgery) and late effects on the tremors were determined clinically and electromyographically. Fourteen parkinsonian cases were treated with minimal lesions (about 40 cu mm). Their late results were very similar to the early results: in 10, the tremors were completely abolished, three had a slight residual tremor, and one underwent reoperation 3 months after the first surgery. Eleven essential tremor cases were treated with minimal lesions. Six of these tremors were completely abolished, four patients had slight residual tremors, and one patient with a recurrence underwent reoperation 2 years after the initial surgery. In these 23 successful operations with minimal lesions (excluding two cases with reoperation), the tremor was abolished without discernible long-lasting side effects. The other 23 operations on 16 patients with Parkinson's disease (including one reoperation) and on seven with essential tremor (one of whom also had a minimal lesion on the other side) involved relatively large lesions. In this group, the surgery was successful in almost every case. It was concluded that radiographically and physiologically monitored selective VIM-thalamotomy for parkinsonian and essential tremor is effective even when lesioning is minimal. Moreover, the beneficial effect is maintained over a long period of time.
The dimensions of the 10 triangles around the cavernous sinus were measured to define the anatomical characteristics of the triangles and to compare their consistency in shape and area. Twelve tissue blocks containing the bilateral cavernous sinuses and medial two-thirds of the middle cranial fossae were obtained from Japanese adults at autopsy, fixed to a stereotactic frame, and examined with an operative microscope. The dimensions of each triangle were measured with calipers and compared, based on the same point and border. The anteromedial triangle and the superolateral (Parkinson's) triangle were more consistent in shape than the paramedial and oculomotor triangles, but the oculomotor triangle was larger in area than these other triangles. The posteromedial (Kawase's) triangle was more consistent in shape and larger than the anterolateral, lateral, and the posterolateral (Glasscock's) triangles. The anteromedial and superolateral (Parkinson's) triangles are important for the combined epi- and subdural approach to cavernous sinus lesions. The posteromedial (Kawase's) triangle is important for gaining access to the posterior cranial fossa from the middle cranial fossa.
We reviewed the computed tomographic findings after 1055 intracranial operations to determine the incidence of postoperative extradural hematomas. There were 11 medium and 5 large hematomas after 1055 operations (1.0%). Ten of the 16 hematomas were operated upon (10/1055, 0.9%). Four of the 10 hematomas were seen after 278 brain tumor removals (1.4%), another four after 190 aneurysmal operations (2.1%), one after 14 intracerebral hematoma removals (7.1%), and the last one after 251 ventricular shunting or drainage procedures (0.4%). In 4 of the 10 operated hematomas, sites were regional, in five sites were adjacent, and in one the site was distant. All of the five adjacent hematomas extended downward from a lower rim of the operative locus. Causes were analyzed in the three types of the hematomas. In case of the regional hematomas, the causes were incomplete hemostasis of the dura mater or the bone in all four patients, nonperformance of central stay sutures in three, systemic hypertension in one, and hypofibrinogenemia in one. In the adjacent hematomas, we could find dural separation at an edge of craniotomy in all five patients, abrupt collapse of the brain in all, ventricular dilatation in two, and systemic hypertension during immediate postoperative period in two. In one distant hematoma, ventricular dilatation and ventricular shunting procedure were themselves thought to be the causal factors.
SUMMARY Three cases with primary writing tremor were treated successfully by stereotactic selective thalamotomy centred mainly on the ventralis intermedius nucleus. They exhibited progressive coarse tremor of 5-7 Hz during writing, and Westphal's phenomenon on stretch, as the only neurological manifestations. Within the thalamus, a very high incidence of irregular burst discharges was recorded. These findings suggest that the writing tremor is an organic disorder.Disordered writing with coarse tremor is frequently observed in patients with Parkinsonism, in those with postural tremor of various causes, and especially in those with action tremor due to cerebellar damage. Writing is used to demonstrate or exaggerate the tremulous movement in these cases. However, there is another type of writing disorder with coarse tremor which has been called primary writing tremor.'-3 This type of writing disorder is distinct from the previous ones in that it is manifested only when the patient intends to write. In pure form, the only problem is with writing, and other daily activities of life are undertaken normally. We present three cases with primary writing tremor, in which stereotactic thalamotomy resulted in complete relief. (fig 2A). The right side was far more markedly affected than the left, which also showed a slighter tendency of grouping. Passive stretch of the muscles revealed exaggerated tonic stretch reflex in biceps and an unequivocal Westphal's shortening reaction, especially in the biceps muscle (when the triceps muscle was stretched). During isometric voluntary contraction, slight tendency of grouped discharge was observed.On 10 March, a left Vim (ventralis intermedius) thalamotomy was performed under local anaesthesia. Using Leksell's stereotactic apparatus, two semimicroelectrodes were introduced to record subcortical extracellular activities toward the tentative target point as described previously.4`The caudate nucleus, and then the upper border of the thalamus were identified by their characteristic neural activities. One of the most interesting findings was that many irregular burst discharges were encountered throughout the thalamic penetration. Several examples are shown in fig 3. Interspike interval histogram showed a second peak corresponding to interburst interval (fig 4). It 988
1. The cytoarchitecture and the exact borders of the thalamic ventralis intermedius (Vim) nucleus of humans as originally delineated by Hassler (17) have been studied on the basis of stereotaxic coordinates correlated with Nissl- and Golgi-impregnated sections, using a microscopic image analyzer. 2. The Vim nucleus forms part of a relatively "cell-sparse zone" which includes the other ventrolateral thalamic subnuclei. It is distinguished by the presence of darkly stained, large and medium sized, angular cells with areas of approximately 500-1,000 microns 2 and 300-400 microns 2, respectively, and a cell density of approximately 50-90 (mean 65)/mm2 in 50-microns-thick sections. 3. Both sets of neurons have the characteristics of thalamocortical relay neurons in Golgi preparations. Large neurons have rectangular or square somata 30-50 microns diam and are concentrated mainly in the lateral and ventral two-thirds of the nucleus. The medium neurons have square to round somata, 15-25 microns diam, and are distributed homogeneously through the nucleus. The total dendritic arborization of both types is usually symmetrical in all directions and at least 500-600 microns diam. 4. The borders between the Vim nucleus and the Nucleus ventrooralis (Vo) and between the Vim nucleus and the Nucleus ventrocaudalis internus (Vci) are clearly identified by clearcut differences in cell size and cell density. The borders between the Vim nucleus and the Nucleus ventrooralis internus (Voi) and between the Vim nucleus and the Nucleus zentrolateralis intermedius (Zim) are quite obscure, and these nuclei, with Vim, seem to be parts of the large cell sparse zone comparable to that described in monkeys as VLp or VL. The border between the Vim nucleus and the Nucleus ventrocaudalis externus anterior (Vcea) is also unclear but the increased cell density and intermingling of small and medium-to-small neurons with large neurons are the major features that distinguish the Vcea nucleus from the Vim nucleus cytometrically. 5. The position and anatomic organization of the human Vim nucleus make it likely that it is the region in which kinesthetic response were recorded in the accompanying paper but extension of the recording sites into the Vcea nucleus cannot be ruled out.
An oblique sagittal magnetic resonance (MR) imaging method was developed to provide better visualization of vascular compression of nerves. The MR images of 12 patients with trigeminal neuralgia and 24 with hemifacial spasm were analyzed. The oblique sagittal views were obtained along the nerve identified by the axial view at an angle of 105 degrees between the line along the dorsal brain stem and the line along the margin of the pontomedullary junction (in patients with hemifacial spasm) or by the midsagittal view through the midpons (in patients with trigeminal neuralgia). The T1- and T2-weighted, proton-density, and/or gradient-echo MR images were evaluated to optimize imaging conditions. The oblique sagittal gradient-echo MR image most clearly visualized vascular compression of the nerves as high-intensity lines in six patients with trigeminal neuralgia, which was confirmed intraoperatively in four. Fifteen (75%) of 20 oblique sagittal gradient-echo MR images demonstrated vascular compression of the facial nerves in patients with hemifacial spasm; 12 of these were confirmed intraoperatively. The control study used 15 oblique sagittal gradient-echo MR images of nonaffected contralateral and normal sites. Four false-positive findings were found. Oblique sagittal gradient-echo MR images are a useful planning aid, allowing differential diagnosis prior to microvascular decompression in trigeminal neuralgia and hemifacial spasm.
Twenty-six cases with spontaneous carotid-cavernous fistulas were followed up for periods ranging between 4 months and 9 years 8 months. A complete regression of symptoms without reappearance for more than 6 months was noted in 19 cases, a marked improvement in 2 cases, and a moderate regression in 3 cases. In 2 cases, symptoms have continued for 9 years 8 months and for 1 year. The regression of symptoms was usually delayed in patients less than 60 years old, in cases in which the symptoms developed slowly, and in cases with multiple draining veins. According to our observations a regression of symptoms may occur after very slight changes of haemodynamics. Compression of the cervical carotid artery for a short time or a temporary occlusion of the carotid artery by a balloon catheter should be considered as the treatment of choice in the first instance in cases with spontaneous carotid-cavernous fistulas showing relatively low pressure and low flow shunt.
SummaryAlthough delayed traumatic intracerebral haematomas (DTICH) have been frequently reported especially after the advent of computerized tomography (CT), the developmental processes of traumatic intracerebral laaematomas and the incidence of DTICH have not been described precisely. Based on early sequential CT examinations of 84 intracerebral haematomas for which initial CT scans were performed as early as within 6 hours of injury, we could ascertain four types of tlhe developmental processes: Type I (39%) included the haematomas which were already evident in the initial CT scans, Type II (11%) the haematomas which were small or medium initially and increased their sizes afterwards, Type III (24%) the haematomas of which admisstion CT scans could not demonstrate any changes at the sites of development of the haematomas, and Type IV (26%) the haematomas of which initial CT scans showed a salt and pepper or flecked high-density appearance. Types III and IV denoted the DTICH and accounted for 50% of all the haematomas. Therefore, DTICH are thought to be not as uncommon as previously reported. Aetiologies and changes in the concepts of the DTICH are discussed, and it is stressed that, in the cases with eventual extra-and intra-cerebral combined ihaematomas, any surgical treatment of an extracerebral haematoma plays an important role in the development of DTICH.
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