Kazuta Yunoki

Topographic electroencephalographic study of transient ischemic attacks

Twenty-five patients with TIAs in the carotid artery distribution were studied by means of computed mapping of EEG (CME) and conventional EEG. In addition, CT scan and cerebral angiography, and in 10 patients rCBF measurements were performed. The CME provided topographic maps of the average power spectra for each of 6 frequency bands from 2.0 to 29.5 Hz which were displayed two-dimensionally in a color-coded isopower format. EEG abnormalities were analyzed and the results of the two different methods of EEG interpretation were compared. Sixty-eight percent of the patients showed unilateral abnormalities on CME appropriately lateralized to the clinical symptoms even after these symptoms had cleared completely. Furthermore, 88% of those who were examined within 2 weeks of last TIA showed corresponding CME abnormalities. Only 3 out of 10 TIA patients who had rCBF studies showed reduction of blood flow on the appropriate hemisphere, whereas 7 of the 10 patients had corresponding CME abnormalities. Comparing the results of the CME and of conventional EEG reading revealed the CME to be slightly more sensitive in detecting asymmetrical voltage depression of background activity than the conventional reading of the EEG, while the latter detected low amplitude sporadic activities which were missed by CME. Both methods were equally sensitive in detecting slow wave foci and non-transient symmetrical changes. The two most significant points of this report are the following: first, 68% of the TIA patients studied had residual unilateral abnormalities in CME in their symptom-free period. In the subset of patients subjected to rCBF studies only 30% showed residual flow aberrations, whereas 70% of the same subset demonstrated unilateral abnormalities in CME. Second, though conventional EEG reading by an experienced electroencephalographer can nearly match the performance of CME the CME format makes subtle but useful EEG findings readily available to the uninitiated. The CME also quantifies the data making objective comparisons more amenable to software manipulations for further studies.

Topographic Electroencephalographic Study of Ischemic Cerebrovascular Disease

Publisher Summary Presence of the slow wave components and slowing, or amplitude depression of background activity on the ischemic side suggest a relationship between cerebral ischemia and the resulting electroencephalographic abnormalities. Polymorphic delta activity and an asymmetrical distribution of background activity are thought to be unilateral signs of the EEG abnormalities in ischemic cerebrovascular disease. The incidences of the resulting EEG abnormalities have differed widely in various studies; these unilateral EEG abnormalities are found in 67.6% of the patients with unilateral cerebral infarction, in 85.7% of those with occlusive cerebrovascular disease, and in 90.3% who had an infarct in the carotid or middle cerebral arterial territory. These variations in the results are considered to depend on some basic factors. The three important factors influencing the resulting EEG abnormalities in cerebral ischemia are as follows: (1) localization of the ischemia area, (2) the duration of the ischemia, and (3) the interval between the onset of ischemia and the recording of the EEG.

Sequential Change of Brain Edema by Semiquantitative Measurement on MRI in Patients with Hypertensive Intracerebral Hemorrhage

The progression of brain edema in seven patients with hypertensive intracerebral hemorrhage (ICH) was evaluated. Five were of putaminal and two were of thalamic hemorrhage. The hematoma volume in the patients was 4 approximately 40 ml (18.9 +/- 8.0 ml). Sequential MRI (SE: 2000/40) was performed at one, two and four weeks after onset. The edema volume (EV) was calculated as 1/2.(long diameter).(short diameter).(thickness) of the high intensity area (HIA) on MRI. In comparison with the EV at one week after onset, the EV at two weeks was increased and the EV at four weeks returned to the same level of that at one week (132.3 +/- 26.1%, 100 +/- 10.6%, respectively). In contrast, the consciousness level and motor weakness of the patients had already improved at two weeks after onset. Our results demonstrate that progression of brain edema after small or medium size ICH may not bring about a deterioration of the clinical course. Moreover, progression of brain edema to the cerebral cortex and ventricle as indicated by MRI suggested an absorption pathway for the edema fluid, and implying that brain edema following ICH could play a part in the healing process after ICH.

A material-control single-case study of the efficacy of treatment for written and oral naming difficulties

Twenty-two right-handed aphasics with written and/or oral naming difficulties were treated with a traditional language therapy: copying and repetition of words. The efficacy and maintainability of the treatment were evaluated using a variation of the single-case design, which was termed the material-control single-case design. Effectiveness of the treatment for written naming difficulty was demonstrated for 9 of 21 subjects in a first treatment and 3 of 14 subjects in a second treatment. Three of the 14 subjects benefitted overall from both treatments in written naming. In oral naming, 2 of 18 subjects responded well to the first treatment while 2 of 16 responded well to the second treatment. One of the 16 subjects showed benefits from both the first and second treatments in oral naming. Although written and oral naming disturbances were difficult to improve using ordinary language treatment, a small proportion of subjects clearly showed effectiveness of the therapy. Maintenance of the effects of treatment was observed in all of the improvers.

Bilateral Thalamic Infarction Associated with Selective Downward Gaze Paralysis

A 34-year-old man presented with transient downward gaze paralysis and impairment of convergence together with prominent psychic disturbances. Cranial CT and MRI clearly demonstrated a symmetric infarction extending from the bilateral thalamus to the rostral medial midbrain. The existence of downward gaze paralysis following ischemic stroke is contributory to the diagnosis of not only the location of but also the responsible artery for the infarction.

CSF β-endorphin and leu-enkephalin levels in the acute and chronic stages of cerebral infarction

SummaryTo investigate the role of endogenous opioid peptides in the pathophysiology of cerebral ischaemia, the CSF levels of immunoreactive β-endorphin and leu-enkephalin in 16 patients with cerebral infarction were measured. Both the CSF β-endorphin and leu-enkephalin levels in the acute stage of cerebral infarction were significantly higher than the values in the chronic stage. The CSF concentrations of the two peoptides revealed a positive correlation in the acute but not the chronic stage. The increased endogenous opioid peptides in the CSF in the acute stage may modify the evolution of cerebral infarction.

Postoperative evaluation of extracranial-intracranial arterial bypass by means of ultrasonic quantitative flow measurement and computed mapping of the electroencephalogram

As an objective evaluation of extracranial-intracranial (EC/IC) bypass operation, we studied 10 patients with occlusive cerebrovascular disease after EC/IC bypass operation using ultrasonic quantitative flow measurement (UQFM) and the computed mapping of the electroencephalogram (CME). After the operation, to evaluate the efficacy of the bypass operation, we studied all patients by UQFM and CME before and during compression of the superficial temporal artery (STA). In a control series of cases, the change in common carotid blood flow during STA compression was not statistically significant, and the findings of CME were unchanged during STA compression. In the cases with bypass surgery, reduction of the common carotid blood flow during STA compression was obvious and statistically significant (P less than 0.001). Additionally, in 5 of the 10 cases, the CME findings were aggravated during STA compression. Therefore, in these 5 cases the brain with bypass seems functionally dependent upon the bypass flow. It is suggested that the EC/IC bypass is effective at least in these 5 cases. The UQFM and the CME, which are noninvasive and simple, are very useful for postoperative evaluation of EC/IC bypass grafts from a hemodynamic and functional point of view.

Effect of Barrier Opening on Brain Edema in Human Brain Tumors

Blood-brain barrier (BBB) opening was carried out in 10 patients with cerebral lesions, and the MRI findings were evaluated following the barrier opening. An intra-arterial injection of 10% glycerol (4 ml/kg, 1 approximately 2 ml/s) was given as a hyperosmotic solution. T2-weighted MRI was undertaken using a TOSHIBA 22A at 30 minutes after BBB opening. Barrier-opening MRI was performed 10 times in 10 patients, including 5 cases of glioblastoma multiforme, 2 cases of astrocytoma, 1 case of malignant lymphoma, 1 case of cerebral contusion and 1 case of neurinoma. The high-intensity area (HIA) was compared with that in MRI without barrier opening. Three types of changes of HIA in MRI were observed after BBB opening as follows. Type 1: Expansion of the HIA was noted in 4 of 5 cases of glioblastoma multiforme, the 1 case of malignant lymphoma and the 1 case of cerebral contusion. Type 2: Almost no change was observed in the 1 case of neuronoma. Type 3: A decrease in HIA was noted in the 2 cases of astrocytoma and in 1 case of glioblastoma multiforme. The MRI following BBB opening evidently showed 3 types of changes according to the degree of BBB disruption. Glioblastoma multiforme or contusion with a severely disrupted BBB revealed an increase in HIA following barrier opening. Benign posterior fossa neurinoma showed no change in HIA after barrier opening. Moderate malignant tumors exhibited a decrease in HIA on barrier-opening MRI. It was concluded that malignant tumors have a severely damaged BBB, which is readily disrupted by osmotic barrier opening.

Increase of plasma methionine-enkephalin level in patients at the acute stage of cerebral infarction

We investigated the participation of endogenous opioid peptide in cerebral ischaemia. In 13 patients with supratentorial infarction, the plasma immunoreactive methionine-enkephalin concentration at the acute stage (30.77 +/- 3.54 pg/ml) was significantly higher than that at the chronic stage (20.37 +/- 2.07 pg/ml) or that of the control subjects (19.64 +/- 1.71 pg/ml). However, it was unrelated to infarct size or patient severity. The increased methionine-enkephalin, which appears to originate from the sympatho-adrenal system or infarcted brain, may play a role in the evolution of cerebral ischaemia.

A New Curved Peritoneal Passer for Shunting Operations — Technical Note

Various operations have been reported for hydrocephalus. Even if these operations consist of minor surgery, general anesthesia or laparotomy is required. To avoiding this complicated type of procedure, we developed a peritoneal and a long subcutaneous passer. This paper indicates the usefulness of these passers for VP shunt operations.