Algorithm for the treatment of mood disorders in Japan

In order to establish algorithms for mood disorders in Japan, over 300 psychiatrists completed a questionnaire. They were asked to recommend various drug treatments for particular cases. The order in which the drugs were recommended was taken into consideration. References were made to the randomized double blind study conducted by the working group. Evidence was ranked according to its probability, with the addition of case reports and medical opinions, since conclusions derived from the randomized double blind study alone did not give a full representation. Japanese documentation was referred to as much as possible in order to represent Japanese characteristics. Algorithms were made for eight subtypes; acute mania, bipolar depression, mild or moderate, severe major depression, psychotic depression, rapid cycling bipolar disorder, dysthymic disorder and major depression with advanced cancer. Major depression and bipolar disorder algorithms are discussed in this paper. Clinical psychopharmacological evidence in Japan was insufficient to generate these algorithms for mood disorders. These algorithms may need revision according to future advances in clinical psychopharmacology. (Int J Psych Clin Pract 1999; 3: 277-285).

Obligatory roles of protein kinase C and nitric oxide in the regulation of cerebral vascular tone: an implication of a pathogenesis of vasospasm after subarachnoid haemorrhage

We previously showed that a canine basilar artery manifested tonic and potent, protein kinase C (PKC)-dependent contractions when nitric oxide (NO) was inhibited. We also reported a linear correlation between chronological changes in the angiographic severity of vasospasm, enhanced PKC, and attenuated guanosine, 13',15'-cyclic monophosphate (cGMP) activity in a canine subarachnoid haemorrhage model. The activity of cGMP is an indicator of NO-function. Based on this evidence, we have hypothesized that PKC and NO regulate cerebral vascular tone. We particularly focused on the role of NO in a negative feedback mechanism on PKC activity in the maintenance of vascular tone. To further confirm our hypothesis, we investigated the effect of PKC down-regulation on the tonic vascular contraction induced by NO-inhibition. Canine basilar artery was used in the experiment. Significant down-regulation of PKC activity in vascular smooth muscle cells was obtained by incubation with 10(-5) mole/L of phorbol 12-myristate 13-acetate (PMA) for 24 hours. The tonic and potent contraction induced by NO-inhibition was completely suppressed in the PKC down-regulated artery, even though the artery manifested a significant contraction in high-K+ solutions. These results indicate an obligatory role of PKC activity in tonic contraction when NO is inhibited, and support our previous data. Nitric oxide induces vascular relaxation by inhibiting PKC activity. Subarachnoid haemorrhage impairs this inhibition, resulting in PKC-dependent vascular contraction, such as vasospasm.

LolA-dependent release of a lipid-modified protein from the inner membrane of Escherichia coli requires nucleoside triphosphate

The outer membrane-directed lipoproteins are released from the inner membrane of Escherichia coli as a complex with LolA, a periplasmic chaperone. The LolA-dependent release of lipoproteins is critical for lipoprotein sorting as it depends on the outer membrane-specific sorting signal. To clarify molecular events involved in the LolA-dependent lipoprotein release, we attempted to establish an in vitro assay system. The major outer membrane lipoprotein (Lpp) was found to lose its release competence soon after being processed to mature Lpp in the inner membrane and therefore could not be used as a substrate for an in vitro system. An Lpp derivative, L10P, was constructed and found to retain the release competence long after its maturation. L10P was synthesized and radiolabeled in spheroplasts in the absence of LolA; therefore, it remained anchored to the inner membrane of spheroplasts. Right-side out membrane vesicles containing L10P were then prepared and used to examine the release of L10P. In addition to LolA, L10P release absolutely required nucleoside triphosphate (NTP). A non-hydrolyzable NTP analogue strongly inhibited the NTP-dependent release. The outer membrane-specific sorting signal was essential for the in vitro release of L10P. Furthermore, L10P released in vitro was specifically incorporated into the outer membrane. These results indicate that the in vitro release of L10P represents an in vivo reaction and requires energy.

Genetic analyses of the in vivo function of LolA, a periplasmic chaperone involved in the outer membrane localization of Escherichia coli lipoproteins

The major outer membrane lipoprotein (Lpp) of Escherichia coli is released from the cytoplasmic membrane into the periplasm as a complex with LolA, a periplasmic chaperone, prior to the localization in the outer membrane. To determine whether or not LolA is generally involved in the outer membrane localization of lipoproteins in vivo, the chromosomal lolA gene was manipulated so as to be controlled by the lac promoter-operator. Depletion of LolA caused a severe growth defect, and impaired the outer membrane localization of Lpp and Pal, another outer membrane lipoprotein. Although LolA depletion did not immediately arrest the growth of cells lacking Lpp, disruption of the chromosomal lolA gene was lethal to the lpp strain, indicating that LolA is generally required for the outer membrane localization of lipoproteins, and therefore essential irrespective of the presence or absence of Lpp.

Simvastatin suppresses glomerular cell proliferation and macrophage infiltration in rats with mesangial proliferative nephritis

Inhibition of 3-hydro-3-methylglutaryl coenzyme A reductase inhibits the production of mevalonate and has been shown to suppress proliferation in many cell types. Therefore, 3-hydro-3-methylglutaryl coenzyme A reductase inhibitors may have a beneficial effect in glomerular disease, because glomerular cell proliferation is a central feature in the active glomerular injury. This study examines the effect of simvastatin on glomerular pathology in a rat mesangial proliferative glomerulonephritis (GN) induced by anti-thymocyte antibody (anti-Thy 1.1 GN). There was no difference in the degree of the antibody and complement-mediated initial injuries between simvastatin-treated and control GN rats. The most pronounced feature of simvastatin-treated GN was the suppression of the early glomerular cell proliferation. The proliferative activity was maximal at day 4 after disease induction (26.5+/-7.0 of proliferating cell nuclear antigen-positive cells/glomerulus); however, approximately 70% of proliferation was suppressed by simvastatin treatment. At day 4 after disease induction, simvastatin administration also decreased alpha-smooth muscle actin expression in the glomerulus, which is a marker for mesangial cell activation. Inhibition of monocyte/macrophage recruitment into glomeruli by simvastatin was also a prominent feature. There was a 30% decrease in the number of glomerular ED-1+ cells by simvastatin treatment at day 2 after disease induction. Furthermore, simvastatin remarkably suppressed subsequent mesangial matrix expansion and type IV collagen accumulation in glomeruli. We also found that the platelet-derived growth factor expression was reduced in simvastatin-treated nephritic rats, which might simply reflect the reduction in mesangial cell proliferation and mesangial cellularity. There was no significant difference in plasma cholesterol or triglyceride levels between simvastatin- and vehicle-treated nephritic rats at day 2 and day 4, which corresponded to the times when simvastatin treatment resulted in a reduction in mesangial cell proliferation. In conclusion, this is the first report to find that mesangial cell proliferation and matrix expansion have been blocked by simvastatin in vivo. The protective effect of simvastatin in the matrix expansion in anti-Thy1.1 GN was partly by inhibition of mesangial cell proliferation and monocyte/ macrophage recruitment into glomeruli, which were independent of a change in circulating lipids.

Plasma dehydroepiandrosterone sulfate in unipolar major depression. Short communication

We investigated plasma dehydroepiandrosterone sulfate (DHEAS) and cortisol levels in 12 patients with unipolar depression and 11 matched normal controls. The depressed patients showed significantly higher values of plasma DHEAS and cortisol than the controls. After 4 weeks of treatment with antidepressants (mainly clomiplamine), the high plasma DHEAS levels recovered. This finding showed the possible relationship between plasma DHEAS levels and depression, as well as cortisol levels.

Effect of dantrolene on KCl- or NMDA-induced intracellular Ca2+ changes and spontaneous Ca2+ oscillation in cultured rat frontal cortical neurons

Dantrolene has been known to affect intracellular Ca2+ concentration ([Ca2+]i) by inhibiting Ca2+ release from intracellular stores in cultured neurons. We were interested in examining this property of dantrolene in influencing the [Ca2+]i affected by the NMDA receptor ligands, KCl, L-type Ca2+ channel blocker nifedipine, and two other intracellular Ca2(+)-mobilizing agents caffeine and bradykinin. Effect of dantrolene on the spontaneous oscillation of [Ca2+]i was also examined. Dantrolene in microM concentrations dose-dependently inhibited the increase in [Ca2+]i elicited by NMDA and KCl. AP-5, MK-801 (NMDA antagonists), and nifedipine respectively reduced the NMDA and KCl-induced increase in [Ca2+]i. Dantrolene, added to the buffer solution together with the antagonists or nifedipine, caused a further reduction in [Ca2+]i to a degree similar to that seen with dantrolene alone inhibiting the increase in [Ca2+]i caused by NMDA or KCl. At 30 microM, dantrolene partially inhibited caffeine-induced increase in [Ca2+]i whereas it has no effect on the bradykinin-induced change in [Ca2+]i. The spontaneous oscillation of [Ca2+]i in frontal cortical neurons was reduced both in amplitude and in base line concentration in the presence of 10 microM dantrolene. Our results indicate that dantrolene's mobilizing effects on intracellular Ca2+ stores operate independently from the influxed Ca2+ and that a component of the apparent increase in [Ca2+]i elicited by NMDA or KCl represents a dantrolene-sensitive Ca2+ release from intracellular stores. Results also suggest that dantrolene does not affect the IP3-gated release of intracellular Ca2+ and that the spontaneous Ca2+ oscillation is, at least partially, under the control of Ca2+ mobilization from internal stores.

Effect of dantrolene on K(+)- and caffeine-induced dopamine release in rat striatum assessed by in vivo microdialysis

Recently, dantrolene has been reported to affect the central nervous system in addition to peripheral targets such as skeletal muscle. We examined effects of dantrolene on K(+)- and caffeine-induced dopamine release in rat striatum using in vivo microdialysis. Perfusion with KCl via the dialysis probe for 20 min induced immediate increase in DA release. Either chelation of extracellular calcium or addition of dantrolene for 120 min preceded reapplication of 100 mM KCl for 20 min. Calcium chelation attenuated the increase in DA release induced by KCl. Application of dantrolene enhanced the KCl-induced increase in DA release, but this effect disappeared at 100 microM. Caffeine caused a dose-dependent increase in dopamine release, independently of extracellular calcium. Treatment with 100 microM dantrolene for 120 min reduced the increase in DA release induced by caffeine. These findings that dantrolene modulates dopamine release in rat striatum indicate that conventionally administered dantrolene is likely to act on the central nervous system.

Differential regulation by pregnenolone sulfate of intracellular Ca2+ increase by amino acids in primary cultured rat cortical neurons

We investigated the effects of pregnenolone sulfate (PS) on the [Ca2+]i increase induced by gamma-aminobutyric acid (GABA) and N-methyl-D-aspartate (NMDA) using fluorescence imaging. PS inhibited the 50 microM GABA-induced increase in [Ca2+]i in a dose-dependent manner with an IC50 of 30 microM. The inhibitory effect of PS was apparent within 5 min and was in a non-competitive manner, suggesting that PS may act directly to the membrane level but indirectly to the GABA binding sites. Our previous study has already shown that the GABA-induced Ca2+ increase involves GABAA receptors and the similar pathway to a high K(+)-induced Ca2+ response (Takebayashi et al., 1996). Because 50 microM of PS could not inhibit a 25 mM K(+)-induced Ca2+ increase, it seems likely that the site of the inhibitory action of PS on the GABA-induced Ca2+ increase may be independent of the pathway of the high K(+)-induced Ca2+ response, but rather at GABAA receptor complex. In contrast, PS potentiated the 50 microM NMDA-induced increase in [Ca2+]i in a dose-dependent manner. The magnitude of the NMDA response was approximately doubled in the presence of 100 microM of PS. However, PS did not affect the acetylcholine(Ach)-induced increase in [Ca2+]i. Furthermore, corticosterone had little effect on the GABA- and NMDA-induced Ca2+ increases, indicating that the alteration of the Ca2+ response is specific for PS. In conclusion, it is suggested that PS modulates differentially [Ca2+]i increase induced by GABA and NMDA.

An isolated case of nephronophthisis: medullary cystic disease without typical onset

A 16-year-old girl with renal failure was transferred to our hospital for an extensive renal examination. Computerized tomography and ultrasonography showed multiple small cysts throughout the medulla of both kidneys. Histological findings revealed tubular atrophy and dilatation and marked periglomerular fibrosis, all of which were compatible with nephronophthisis. Her development and growth were normal. A prior urinalysis, as well as her symptoms and family history were not helpful for making a diagnosis. As early diagnosis of nephronophthisis is difficult in some cases, more detailed screening is needed for children and adolescents.

Effectiveness of valproate on delirium and/or aggressive behavior in demented patients: A practical pilot study

This open study was designed to evaluate the efficacy of valproate as a treatment for delirium and/or aggressive behavior in patients with dementia. Of the patients who participated, nine had vascular dementia, two had Alzheimer's disease, one had Parkinson's disease and one had alcohol dependence, all meeting DSM-IH-R criteria for dementia. In these 13 patients, delirium in seven and aggressive behavior in 12 patients were the target symptoms of this study. Valproate was administered orally at a dose of 200-600 mg daily (mean 526 mg, sd=20.4) without changing the dose of the other medications. The effect of valproate on delirium and aggressive behavior was evaluated with the Delirium Rating Scale (DRS) and Gottfries-Brane-Steen Scale (GBS). The total DRS scores decreased in 6/7 patients with delirium (P < 0.05) within 2 weeks. There were significant diferences between the score variances (before and during treatment) of the three categories in the GBS scale: emotional lability (P < 0.01), irritability (P < 0.01) and restlessness (P < 0.01). These findings suggest the effectiveness of valproate treatment for delirium and/or aggressive behavior in demented patients.

Tissue-specific regulation of renal and cardiac atrial natriuretic factor gene expression in deoxycorticosterone acetate-salt rats

Atrial natriuretic factor (ANF) is expressed in several noncardiac tissues where it may have an autocrine or paracrine function. Such function may be expected of locally synthesized ANF in the renal parenchyma. Previous investigations of the existence of ANF mRNA in the renal parenchyma have yielded conflicting results. The investigations reported here were designed to detect and measure ANF mRNA in normal rats and in rats subjected to a deoxycorticosterone acetate (DOCA)-salt treatment schedule known to strongly activate cardiac ANF gene expression. The expression of the renal ANF gene was measured using a newly developed quantitative competitive reverse transcription-polymerase chain reaction (QC-RT-PCR). This method uses an internal competitor that serves as an internal standard and makes the procedure independent of measurement relative to housekeeping genes. It was found that renal ANF mRNA levels were 10(7) times lower than those found in left or right atria, but immunoreactive (ir) renal ANF concentration by specific radioimmunoassay was 10(4) times lower than that of atrial irANF levels. Reverse-phase high-performance liquid chromatography analysis revealed that more than 99% of renal irANF is processed ANF(99-126). This finding suggests that most of the irANF measured in kidney extracts likely originates from atrial sources. Left atrial ANF mRNA levels after 1 week of DOCA-salt treatment was significantly higher than that of control rats ([21.06+/-2.99] x 10(-l5) mol/microg total RNAversus [8.59 +/-1.26] x 10(-5) mol/microg total RNA, P<.05). However, renal ANF mRNA levels in DOCA-salt rats were significantly decreased compared with those of control rats ([1.64+/-0.34] x 10(-22) mol/microg total RNA versus [3.96+/-0.61]x 10(-22) mol/microg total RNA, P<.05). These results indicate that (1) renal ANF mRNA can be consistently and specifically demonstrated after reverse transcription and PCR amplification; (2) renal and cardiac ANF synthesis are regulated in a tissue-specific, opposite manner during DOCA-salt treatment; and (3) the finding that renal ANF mRNA is downregulated by DOCA-salt treatment together with previous findings suggest the need for further investigation into the role of renal ANF mRNA downregulation in the pathogenetic mechanism that leads to volume expansion and hypertension after chronic DOCA-salt treatment.

A novel outer membrane lipoprotein, LolB (HemM), involved in the LolA (p20)-dependent localization of lipoproteins to the outer membrane of Escherichia coli

The Escherichia coli major outer membrane lipoprotein (Lpp) is released from the inner membrane into the periplasm as a complex with a carrier protein, LolA (p20), and is then specifically incorporated into the outer membrane. An outer membrane protein playing a critical role in Lpp incorporation was identified, and partial amino acid sequences of the protein, named LolB, were identical to those of HemM, which has been suggested to play a role in 5-aminolevulinic acid synthesis in the cytosol. In contrast to this suggested role, the deduced amino acid sequence of HemM implied that the gene encodes a novel outer membrane lipoprotein. Indeed, an antibody raised against highly purified LolB revealed its outer membrane localization, and inhibited in vitro Lpp incorporation into the outer membrane. Furthermore, LolB was found to be synthesized as a precursor with a signal sequence and then processed to a lipid-modified mature form. An E.coli strain possessing chromosomal hemM under the control of the lac promoter-operator required IPTG for growth, indicating that hemM (lolB) is an essential gene. Outer membrane prepared from LolB-depleted cells did not incorporate Lpp. When the Lpp-LolA complex was incubated with a water-soluble LolB derivative, Lpp was transferred from LolA to LolB. Based on these results, the outer membrane localization pathway for E.coli lipoprotein is discussed with respect to the functions of LolA and LolB.

Urine and plasma levels of uroguanylin and its molecular forms in renal diseases

Uroguanylin activates the intestinal and possibly the renal guanylate cyclase C receptor, and stimulates Cl- secretion. We developed a sensitive radioimmunoassay (RIA) for human uroguanylin and measured its concentration in the urine and plasma. Twenty-four-hour urinary excretion of immunoreactive (ir-) uroguanylin for persons with a high-salt diet (10 g/day) was 137.8 +/- 14.4 pmol/day, significantly higher than that for persons with a low-salt diet (7 g/day, 95.1 +/- 16.3 pmol/day, P < 0.05). There were significantly positive correlations between the urinary excretion of ir-uroguanylin and Na+, Cl-, K+ or cyclic GMP (cGMP). We demonstrated the presence of messenger RNA of guanylate cyclase C in the medulla of human kidney. The concentration of plasma ir-uroguanylin significantly correlated with that of serum creatinine (r = 0.71, P < 0.001). Biologically active uroguanylin-16 accounted for 99% of the endogenous uroguanylin molecules in normal urine and 60% in plasma, the remainder being the 10 kDa precursor. The precursor content increased in the urine and plasma as the severity of renal impairment increased. These findings suggest that bioactive uroguanylin-16 is involved in the regulation of electrolyte homeostasis and that the kidney participates in the metabolism and excretion of uroguanylin.

Benefits of trazodone and mianserin for patients with late-life chronic schizophrenia and tardive dyskinesia: an add-on, double-blind, placebo-controlled study

The objective of the present study was to evaluate the efficacy of mianserin and trazodone as antidepressants with serotonin 2 antagonist properties on negative symptoms and tardive dyskinesia in elderly patients with chronic schizophrenia. In this double-blind, placebo-controlled study the dose of each drug was increased gradually, from 20 mg/day mianserin to 60 mg/day, and from 50 mg/day trazodone to 200 mg/day. Symptoms were assessed using the Brief Psychiatric Rating Scale, the Scale for Assessment of Negative Symptoms and the Abnormal Involuntary Movement Scale every week for 5 weeks. A total of 38 patients (23 men and 15 women) completed the trial. Mianserin (n = 13) and trazodone (n = 12) did not alter the Brief Psychiatric Rating Scale positive symptom factor over the 5 weeks. In the mianserin group, the Scale for Assessment of Negative Symptoms total score decreased significantly after 5 weeks. Scores of 'affective flattening and blunting' and 'alogia' scores on the Scale for assessment of Negative Symptoms decreased significantly in both treatment groups. In the trazodone group, the decrease in the Abnormal Involuntary Movement Scale total score was statistically significant at weeks 2 and 3. Results indicate that serotonergic antidepressants, when used in conjunction with neuroleptics, are safe and effective for treating negative symptoms in elderly patients with chronic schizophrenia. Results also indicated a possible beneficial effect of trazodone in treating tardive dyskinesia.

Visual evoked potential guidance for posteroventral pallidotomy in Parkinson's disease

Visual evoked potentials (VEPs) to photic stimulation of the eyes were used to identify the optic tract and thus determine the location of the globus pallidus internus (GPi) in eight patients with Parkinson's disease who then underwent posteroventral pallidotomy. Distinct waves appeared at 1 or 2 mm below the target (4 to 5 mm below the intercommissural line) and the amplitude significantly increased at 5 or 6 mm below, strongly suggesting that the electrode was in contact with the optic tract. In the medio-lateral direction, potentials were successively recorded in an area of 4 to 8 mm length, indicating the width of the optic tract. The trajectory at the mid point showed the most significant potentials which suggested the center of the optic tract. The site of the first lesion was placed 0 to 2 mm lateral to this trajectory and 5 mm above the point at which the amplitudes of responses increased. The actual lesion site significantly differed from the tentative target in a medio-lateral direction by 1 to 5 mm (mean 3.0 +/- 1.5 mm, n = 6). The Unified Parkinson's Disease Rating Scale score significantly improved and magnetic resonance imaging taken 2 or 3 weeks after the operation showed a lesion within the GPi in each patient. Recording of VEPs greatly facilitates accurate determination of the GPi.

Chronic treatment with antidepressants, verapamil, or lithium inhibits the serotonin-induced intracellular calcium response in individual C6 rat glioma cells

The effects of chronic treatment with antidepressants, verapamil, or lithium on serotonin (5-HT)-induced Ca2+ increase were investigated in single C6BU-1 glioma cells with digital imaging microscopy. Clomipramine and citalopram, at a concentration of 100 nM, decreased the peak values of 5-HT-induced [Ca2+]i changes. Verapamil (100 nM), a calcium antagonist, and lithium (1 mM) also inhibited the peak amplitudes in the same way. The present findings suggest that chronic treatment with antidepressants, verapamil, or lithium, at therapeutic concentrations, have the common action of inhibiting 5-HT-mediated [Ca2+]i increase.

[Objective measurement of motor activity in Parkinson's disease by actigraphy. Clinical assessment of akinesia]

Actigraphy measures physiological activity by using an acceleration sensor and RAM equipped with a data logger. Since actigraphy can continuously and easily record data over a long period of time without disturbing the normal activities of subjects, it is possible to analyze a large number of subjects. Actigraphy was performed in patients with Parkinson's disease who did not exhibit trembling. Results showed that the daily motor activity of patients was lower than that of the healthy individual. Daily motor activity was also found to be correlated with Hoehn-Yahr's classification. Furthermore, side-effects due to L-dopa, such as abnormal involuntary movement and on-off phenomenon, could be objective assessed. The results of long-term actigraphic examination, conducted after anti-Parkinsonian treatment, showed that akinesia improved with time. From these findings, it is concluded that actigraphy could quantitatively assess the degree of akinesia in Parkinsonian patients. Furthermore, actigraphy may be applied to the clinical assessment of drugs.

Response of patients with major depression and silent cerebral infarction to antidepressant drug therapy, with emphasis on central nervous system adverse reactions

BACKGROUND AND PURPOSE

We previously found that silent cerebral infraction (SCI) is present in most patients older than 50 years with major depression. The present study was designed to clarify the response to antidepressant pharmacotherapy in patients with major depression associated with SCI.

METHODS

Using clinical charts, we retrospectively studied patients older than 50 years who were admitted for antidepressant drug therapy. Patients with bipolar affective disorder and those with focal neurological symptoms were excluded. All patients underwent magnetic resonance imaging and were classified as SCI-negative or SCI-positive. The SCI-positive group was subclassified into those with moderate SCI (either perforating area or cortical area) (n = 15) and those with severe SCI (both perforating and cortical areas) (n = 7). Duration of treatment in hospital and the incidence of central nervous system adverse reactions to the antidepressant drugs were compared between the two groups.

RESULTS

The duration of hospital treatment in patients with severe SCI was significantly longer than in those with moderate SCI (P < .01). The percentage of patients with adverse central nervous system reactions to antidepressant drugs was significantly higher in the SCI-positive group than in the SCI-negative group (P < .05). Patients with severe SCI had significantly more adverse reactions than those with moderate SCI (P < .05).

CONCLUSIONS

Depressed patients with severe SCI required longer hospital treatment and had more drug-related adverse reactions of the central nervous system. These findings suggest that the depression associated with severe SCI may be resistant to treatment.

[Tactile extinction following the cerebral sinus thrombosis. A study using event-related potentials]

We reported a 46-year-old woman in whom cerebral sinus thrombosis manifested itself in headache and weakness while she was on an oral estrogen preparation. The neurological examinations revealed monoparesis of the right upper extremity, hyperactive right deep tendon reflex and disturbance of the joint sense, stereognostic sense, two-point discrimination and skin writing sense in the right upper extremity, in addition to tactile extinction. Brain CT showed empty triangle sign. MRI revealed infarction near the left postcentral gyrus and thrombosis of right sigmoid sinus. In the MRA study, there was low signal intensity in the posterior portion of the superior sagittal sinus and right transverse sinus. Short latency SEP in upper extremity showed that the central conduction time was normal, while the amplitude of wave components after N20 was reduced on the right side. Both palms were given bilateral or unilateral pressure stimuli. When event-related potentials (ERP) were evoked, using bilateral stimuli as a rare target, and left unilateral stimuli as a non-target, the P 300 latency was prolonged to 450 msec but was restored to normal with the improvement of tactile extinction. These results seem to suggest that the tactile extinction is ascribable to a disturbance of recognition at the higher brain function level and that ERP can be a useful objective yardstick in the evaluation of extinction phenomenon.