Yoshishige Nagaseki

Postoperative Extradural Hematomas: Computed Tomographic Survey of 1105 Intracranial Operations

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.

Long-term observations in cases with spontaneous carotid-cavernous fistulas.

SummaryTwenty-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.

The incidence and developmental process of delayed traumatic intracerebral haematomas

SummaryAlthough delayed traumatic intracerebral haematomas (DTICH) have been frequently reported especially after the advent of computerized tomography (CT), the developmental processes of traumatic intracerebral haematomas 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 the 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 haematomas, any surgical treatment of an extracerebral haematoma plays an important role in the development of DTICH.

Music alexia in a patient with mild pure alexia: disturbed visual perception of nonverbal meaningful figures.

A 26-year-old female pianist suffered from an intracerebral hematoma caused by an arteriovenous malformation of the left occipital parasplenial region, which was operated on seven months after the onset. Incomplete right hemianopsia, mild pure alexia, and partially disturbed naming of visual objects persisted several months after the removal of the malformation. Evaluation of musical ability one and three months after surgery showed that her auditory recognition of music was intact. She could sing and play melodies already learned and could dictate well the notes after hearing tones. However, she had difficulty in reading music, especially the pitch of notes, even for simple sequences of 4 notes. In contrast, her rhythm reading was fairly good. Her visual recognition of other symbolic figures like road signs was also markedly impaired. These results suggest that her visual recognition of written music as well as of other symbolic figures underwent a preliminary verbal decoding in the left hemisphere and that pitch reading was more dependent on verbal processing than rhythm reading.

Primary internal ophthalmoplegia due to head injury

SummarySix cases of internal ophthalmoplegia due to direct head injury are presented. All six patients had a dilated, nonreactive pupil. Four had no extraocular palsies or ptosis and two had partial extraocular palsies or ptosis. Disturbance of consciousness was absent or very mild, and all patients fully recovered within 1 to 7 days after the traumatic event. No patient had a history that suggested a cause for oculomotor nerve palsy, and emergency CTscans showed no mass lesions. The internal ophthalmoplegia was recognized immediately after trauma. Although minimal oculomotor nerve palsies due to unruptured intracranial aneurysms have been described, none of our patients complained of periorbital or retroorbital pain either before or after the trauma, which rules out intracranial aneurysms as the cause of the internal ophthalmoplegia. Therefore, we concluded that the internal ophthalmoplegia was due to direct head injury. The pathophysiological mechanism of the internal ophthalmoplegia appeared to be slight injury of the pupillomotor fibres on the ventromedial surface of the third nerve at the posterior petroclinoid ligament, which acted as the fulcrum due to the downward displacement of the brainstem at the time of impact.

The Incidence of Delayed Traumatic Intracerebral Hematoma with Extradural Hemorrhages

After introduction of computerized tomography (CT), we experienced 22 patients with traumatic extradural and intracerebral combined hematomas, of whom 15 underwent sequential CT scans. In 14 of the 22 patients or 13 of the 15 patients whose initial CT scans were performed early, within 6 hours after injury, intracerebral hematomas developed more slowly than extradural hematomas. In ten of the 13 patients, development of intracerebral hematomas was demonstrated only after removal of extradural hematomas, and in four patients acute brain swelling was observed during surgery. Therefore it is emphasized that the incidence of post-surgical intracerebral hematoma with extradural hemorrhages is high and that acute brain swelling during surgery for extradural hematomas is largely caused by the delayed intracerebral hematomas.

Prediction of Vertebral Artery Compression in Patients with Hemifacial Spasm Using Oblique Sagittal MR Imaging

Summary To discriminate between the various compressing vessels of the facial nerves in patients with hemifacial spasm, pre-operative oblique sagittal gradient-echo MR imaging was performed. Forty-two patients underwent pre-operative MR imaging and microvascular decompression. The MR images were divided according to findings into three groups as follows: Group A, a thick and/or long high-intensity line along the root exit zone (REZ) of the facial nerve; Group B, a thin and/or short high-intensity line along the REZ; and Group C, an unreliable image around the REZ. Fifteen images were classified as Group A, 19 as Group B, and 8 as Group C. In Group A, vertebral artery (VA) compression was confirmed intra-operatively in 12 cases and posterior inferior cerebellar artery (PICA) or anterior inferior cerebellar artery (AICA) compression in 3. In Group B, PICA or AICA compression was confirmed intra-operatively in all cases. In Group C, PICA or AICA compression was confirmed intra-operatively in 7 cases and no compression in one. In all cases of VA compression of the facial nerve, the oblique sagittal gradient-echo images demonstrated a thick and/or long high intensity line along the REZ. Oblique sagittal gradient-echo MR imaging is a useful pre-operative planning aid, which can predict the possibility of VA compression prior to microvascular decompression for hemifacial spasm.

Symmetrical bilateral low-density lesions in the areas of supply by Heubner's arteries after aneurysm surgery.

SummaryThree patients with symmetrical bilateral low-density areas which were the perfusion territories of Heubners arteries are reported. The infarctions were demonstrated on computed tomography after aneurysm surgery. Two of them had an anterior communicating artery aneurysm and the other one had multiple aneurysms of both sides. They were operated upon in the acute stage after subarachnoid haemorrhage. As common factors, a thick and diffuse subarachnoid haemorrhage, an acute-stage operation, temporary clips to bilateral A1 segments or the internal carotid artery and a relatively low systemic blood pressure during operation were found. From these findings we concluded that the pathogenesis of the infarctions was due to occlusive changes affecting Heubners arteries bilaterally.

Stereotactic Selective Thalamotomy for the Treatment of Tremor Type Cerebral Palsy in Adolescence

6 cases with tremor-athetotic type cerebral palsy and 2 cases with moderate dystonia-tremor type cerebral palsy were treated by selective stereotactic thalamotomy. In the former group, postural-movement type tremor in the upper limb gradually progressed with age while athetosis remained unchanged. In the latter group, dystonia in the truncal muscles predominated over the irregular tremulous movement of the upper limbs. In all cases, the intelligence was almost normal. Stereotactic selective thalamotomy (Vim for tremor athetosis, VL-Vim for dystonia tremor) was performed under local anesthesia with the aid of radiological and neurophysiological control methods. The results of the operations were satisfactory in regard to the tremor relief and concomitant improvement of motor performances in most of the cases. Stereotactic treatment might be an effective way to make possible a one-step progress in these handicapped cases. The importance of postoperative physical therapy is also emphasized.

Cell Sparse Zones in the Ventrolateral Thalamic Mass in Humans, Monkeys and Cats: Their Special Reference to Kinesthetic Neurons

The Vim nucleus of the human thalamus is the cell sparse zone. The neurons in this zone respond to peripheral stimuli of kinesthetic modality with a short latency. In the cytometrical study, the cell sparse zone is identifiable in both the monkey and cat thalamus. The cell dimension and density in a 1 mm2 area in the cell sparse zone of each species are as follows: humans--large neuron 500-900 microns2, medium neuron 200-400 microns2, cell density 60-90/mm2/50 microns thickness; monkeys--large neuron 400-800 microns2, medium neuron 200-400 microns2, cell density 120-250/mm2/50 microns thickness; cats--large neuron 400-800 microns2, medium neuron 200-400 microns2, cell density 120-250/mm2/50 microns thickness. In this zone, there are large and medium thalamocortical relay neurons defined by the Golgi impregnated and HRP studies. It is still obscure which neurons respond to kinesthetic stimulation and which neurons or afferent fibers play important roles in the tremor mechanism.