Effects of procyclidine on prepulse inhibition of the acoustic startle response in healthy human volunteers

RATIONALE

Prepulse inhibition (PPI) of the startle response refers to an attenuation in response to a strong stimulus (pulse) if this is preceded shortly by a weak non-startling stimulus (prepulse). Patients with schizophrenia have repeatedly been found to show reduced PPI when compared to healthy people. Anticholinergic drugs are often used to control extrapyramidal symptoms induced by antipsychotic medication in schizophrenic patients. Antipsychotic medication, in particular with atypical drugs, has been shown to improve a range of cognitive functions and normalize PPI deficits in schizophrenia, whereas anticholinergic drugs disrupt cognitive functions in both normal and schizophrenic populations and also impair PPI in experimental animals. No previous study has investigated the effects of anticholinergic drugs on human PPI.

OBJECTIVES

This study determined the effects of procyclidine, an anticholinergic drug, on PPI in healthy male volunteers, employing a double-blind placebo-controlled cross-over design.

METHODS

Subjects underwent testing for PPI on two occasions: once after the oral administration of a placebo and once after the oral administration of procyclidine in two separate experiments. Experiment 1 examined the effects of 10 mg procyclidine, whereas experiment 2 examined the effects of 15 mg procyclidine.

RESULTS

Procyclidine at a 10 mg dose, as compared to placebo, had no effect on PPI, but caused impairments at a 15 mg dose. In both experiments, procyclidine reduced response amplitude over the pulse-alone trials and heart rate 1-2 h post-administration.

CONCLUSIONS

PPI of the human acoustic startle response is modulated by procyclidine. The use of anticholinergics needs to be considered in PPI studies in schizophrenia.

Endolaser around macular hole in the management of associated retinal detachment in highly myopic eyes

PURPOSE

To analyze the role of endolaser around macular hole in managing associated retinal detachment in patients with high myopia.

METHODS

Review of medical records of 25 consecutive eyes of 25 patients with at least 5.00 diopters of myopia who underwent primary pars plana vitrectomy and fluid-gas exchange. In the first half of the study period, one row of contiguous argon green endolaser was routinely applied over the retinal edge of the macular hole (EL group). In the second half of the study period, endolaser was not applied around any macular hole (NEL group). Demographic information, intraoperative and postoperative complications, and final visual acuities and retinal reattachment rates were studied.

RESULTS

The mean (+/-SD) refractive error was -11.8 +/- -3.5 diopters (D) for the EL group and -11.6 +/- -5.4 D for the NEL group. The mean axial length was 29.0 +/- 1.8 mm for the EL group and 28.3 +/- 1.7 mm for the NEL group. The primary anatomic success was 62.5% (10/16) and 77.8% (7/9) in the EL and NEL groups, respectively. No statistically significant difference was found in preoperative, postoperative, or change in best-corrected visual acuities between the two groups.

CONCLUSION

Endolaser around the macular hole after pars plana vitrectomy and internal gas tamponade may not affect the anatomic or visual outcome in primary retinal detachment secondary to a highly myopic macular hole.

Three-dimensional mapping of gyral shape and cortical surface asymmetries in schizophrenia: gender effects

OBJECTIVE

People with schizophrenia exhibit abnormalities in brain structure, often in the left hemisphere. Disturbed structural lateralization is controversial, however, and effects appear mediated by gender. The authors mapped differences between schizophrenic and normal subjects in gyral asymmetries, complexity, and variability across the entire cortex.

METHOD

Asymmetry and shape profiles for 25 schizophrenic patients (15 men) and 28 demographically similar normal subjects (15 men) were obtained for 38 gyral regions, including the sylvian fissure and temporal and postcentral gyri, by using magnetic resonance data and a novel surface-based mesh-modeling approach. Cortical complexity was examined for sex and diagnosis effects in lobar regions. Intragroup variability was quantified and visualized to assess regional group abnormalities at the cortical surface.

RESULTS

The patients showed greater variability in frontal areas than the comparison subjects. They also had significant deviations in gyral complexity asymmetry in the superior frontal cortex. In temporoparietal regions, significant gyral asymmetries were present in both groups. Sex differences were apparent in superior temporal gyral measures, and cortical complexity in inferior frontal regions was significantly greater in men.

CONCLUSIONS

Cortical variability and complexity show regional abnormalities in the frontal cortex potentially specific to schizophrenia. The results indicate highly significant temporoparietal gyral asymmetries in both diagnostic groups, contrary to reports of less lateralization in schizophrenia. Substantially larger study groups are necessary to isolate smaller deviations in surface asymmetries, if present in schizophrenia, suggesting their diagnostic value is minimal.

Mapping motor inhibition: conjunctive brain activations across different versions of go/no-go and stop tasks

Conjunction analysis methods were used in functional magnetic resonance imaging to investigate brain regions commonly activated in subjects performing different versions of go/no-go and stop tasks, differing in probability of inhibitory signals and/or contrast conditions. Generic brain activation maps highlighted brain regions commonly activated in (a) two different go/no-go task versions, (b) three different stop task versions, and (c) all 5 inhibition task versions. Comparison between the generic activation maps of stop and go/no-go task versions revealed inhibitory mechanisms specific to go/no-go or stop task performance in 15 healthy, right-handed, male adults. In the go/no-go task a motor response had to be selectively executed or inhibited in either 50% or 30% of trials. In the stop task, the motor response to a go-stimulus had to be retracted on either 50 or 30% of trials, indicated by a stop signal, shortly (250 ms) following the go-stimulus. The shared "inhibitory" neurocognitive network by all inhibition tasks comprised mesial, medial, and inferior frontal and parietal cortices. Generic activation of the go/no-go task versions identified bilateral, but more predominantly left hemispheric mesial, medial, and inferior frontal and parietal cortices. Common activation to all stop task versions was in predominantly right hemispheric anterior cingulate, supplementary motor area, inferior prefrontal, and parietal cortices. On direct comparison between generic stop and go/no-go activation maps increased BOLD signal was observed in left hemispheric dorsolateral prefrontal, medial, and parietal cortices during the go/no-go task, presumably reflecting a left frontoparietal specialization for response selection.

A three-dimensional and temporo-spatial model to study invasiveness of cancer cells by heregulin and prostaglandin E2

To study the temporal expression of motile structures and protease activity during colon cancer cell invasion by heregulin-beta1 (HRG) and prostaglandin E2 (PGE2), we have developed a three-dimensional spatial model system. HRG and PGE2 each induced the formation of well-organized, three-dimensional structures with empty spaces in the center and stimulated the expression of urokinase plasminogen activator (uPA) with differential localization of membrane-bound uPA at the focal adhesion points and leading edges of the motile cells. A specific cyclooxygenase-2 inhibitor blocked the formation of three-dimensional luminal glandular structures induced by HRG but did not block those induced by PGE2. A specific antagonist of uPA receptor completely blocked the formation of these luminal glandular structures induced by PGE2 and HRG. These findings suggest that HRG-mediated increased invasiveness of colon cancer cells is augmented at least in part by induction of PGE2 and uPA, and this augmentation may involve the formation of three-dimensional invasive structures via the uPA pathway. In addition, the three-dimensional model system presented here may have a wider application to screen the effects of therapeutic compounds and biomolecules on different spatial aspects of colonic biology, including cell growth, motility, invasion, survival, and apoptosis.

Magnetic resonance imaging of the thalamus in first-episode psychosis

OBJECTIVE

There is some evidence of thalamic abnormalities in schizophrenia. This study investigated thalamic volumes in patients experiencing their first episode of psychosis and nonpsychotic comparison subjects.

METHOD

Magnetic resonance imaging scans were obtained for 38 patients and 29 comparison subjects. Patients' symptoms were rated by research psychiatrists using the Positive and Negative Syndrome Scale.

RESULTS

Thalamic volumes were smaller in patients than in comparison subjects. There were no significant correlations between thalamic volumes and symptom scores.

CONCLUSIONS

Thalamic abnormalities are present close to the onset of psychosis.

Butyric acid induces apoptosis by up-regulating Bax expression via stimulation of the c-Jun N-terminal kinase/activation protein-1 pathway in human colon cancer cells

BACKGROUND & AIMS

The colonic epithelial cells near the top of the crypt have been shown to undergo apoptosis. Because butyric acid (BA) is the major short-chain fatty acid produced by fermentation of dietary fiber in the large bowel, it may be an important regulator of apoptosis in colorectal cancer. We investigated which signaling pathway is triggered by BA to undergo apoptosis in human colorectal cancer cells.

METHODS

Human DiFi and FET colorectal cells were treated with BA to undergo apoptosis and were assayed for activation of c-Jun N-terminal kinase (JNK), transcription factor activation protein 1 (AP1) and NF-kappaB, and the proapoptotic molecule Bax. The contribution of specific pathways was assessed by examining the effects of dominant-negative mutants of JNK/AP1 or NF-kappaB on BA-induced Bax expression and apoptosis.

RESULTS

BA-mediated DNA fragmentation and Bax induction were preceded by early stimulation of JNK, and the DNA-binding activities of AP1 and NF-kappaB. BA-induced enhancement of DNA fragmentation and stimulation of Bax promoter activity were blocked by the expression of dominant-negative mutants of JNK1 or AP1 but not NF-kappaB.

CONCLUSIONS

These findings suggest that apoptosis triggered by BA involves transcriptional stimulation of the Bax gene via activation of the JNK/AP1 pathway in colonic epithelial cells.

Exploring the social brain in schizophrenia: left prefrontal underactivation during mental state attribution

OBJECTIVE

Evidence suggests that patients with schizophrenia have a deficit in "theory of mind," i.e., interpretation of the mental state of others. The authors used functional magnetic resonance imaging (MRI) to investigate the hypothesis that patients with schizophrenia have a dysfunction in brain regions responsible for mental state attribution.

METHOD

Mean brain activation in five male patients with schizophrenia was compared to that in seven comparison subjects during performance of a task involving attribution of mental state.

RESULTS

During performance of the mental state attribution task, the patients made more errors and showed less blood-oxygen-level-dependent signal in the left inferior frontal gyrus.

CONCLUSIONS

To the authors' knowledge, this is the first functional MRI study to show a deficit in the left prefrontal cortex in schizophrenia during a socioemotional task.

Experience of caregiving: relatives of people experiencing a first episode of psychosis

BACKGROUND

There has been relatively little research on caregivers of people experiencing their first episode of psychosis.

AIMS

To investigate dimensions of caregiving and morbidity in caregivers of people with first-episode psychosis.

METHOD

Caregivers of 40 people with first-episode psychosis were interviewed at home about their experience of caregiving, coping strategies and distress.

RESULTS

Caregivers used emotional and practical strategies to cope with participants' negative symptoms and difficult behaviours and experienced more worry about these problems. They increased supervision when the participants displayed difficult behaviours. Twelve per cent of caregivers were suffering from psychiatric morbidity as defined by the General Health Questionnaire. Those living with the participant had more frequent visits to their general practitioner.

CONCLUSIONS

At first-episode psychosis, caregivers are already having to cope with a wide range of problems and are developing coping strategies. Caregivers worried most about difficult behaviours and negative symptoms in participants.

Recent developments in vitreoretinal surgery

In the past three decades, a great improvement has occurred in microsurgical techniques used in the management of various eye diseases involving retina and vitreous. Advances in instrumentation has made the surgery easier and refined. The instruments used are narrated widely in this article. Various vitreous substitutes have been developed and are required in vitreoretinal surgery. These are gases, silicone oil, perfluorocarbon liquids and fluorosilicone oil. Anterior segment indications for vitreous surgery are: Vitreous loss during cataract surgery, thick after cataracts that can't be managed with Nd: YAG capsulotomy, vitreocorneal touch, updrawn pupils, incarcerated vitreous in the wound causing cystoid macular oedema, malignant glaucoma, penetrating keratoplasty in aphakic patients, congenital cataracts and filtering procedures in aphakic eyes. In posterior segment indications, vitrectomy is useful in penetrating trauma, haemorrhage, retinal deetachment, intra-ocular foreign bodies and infection endophthalmitis Macular surgery involves peeling of epimacular membrane or proliferation, treating vitreomacular traction syndrome, idiopathic macular holes, retinal detachment associated with optic pit, evacuation of submacular haemorrhage and excision of choroidal neovascular membranes. Available options to treat retinal detachments are pneumatic retinopexy, scleral buckling and vitreous surgery. Proliferative vitreoretinopathy remains the important cause of failure and occurs in about 8-10% cases after retinal detachment. Vitreous surgery for ocular trauma, vitrectomy for proliferative diabetic retinopathy, macular hole surgery, submacular surgery are also discussed in detail.

The 10th Biennial Winter Workshop on Schizophrenia. A report

The 10th Biennial Winter Workshop on Schizophrenia (5-11 February 2000), organized by Drs Tim Crow and Steven Hirsch, attracted a wide range of contributions, not only from European countries, but from all across the world, encompassing clinical, neuropsychological, cognitive, experimental, pharmacological and neuroimaging approaches to enhance the understanding of possible causes, features and the treatments of this illness. The Kongresszentrum, Davos, Switzerland was once again the venue. We present a flavour of the variety of presentations, the news and the views emerging from these presentations, and discuss their implications for further advancement in the field of schizophrenia research.

Features of structural brain abnormality detected in first-episode psychosis

OBJECTIVE

Structural magnetic resonance imaging (MRI) studies that focus on first-episode psychosis avoid some common confounds, such as chronicity of illness, treatment effects, and long-term substance abuse. However, such studies may select subjects with poor short-term treatment response or outcome. In this study, the authors focus on structural brain abnormalities in never or minimally treated patients who underwent MRI scanning early in their first episode of psychosis.

METHOD

The authors examined 37 patients (13 medication naive, 24 previously treated) who were experiencing their first episode of psychosis; the mean duration of symptoms was short (31 weeks). These patients were comparable in age, gender, handedness, ethnicity, and parental socioeconomic status to a group of 25 healthy comparison subjects. A three-dimensional, inversion recovery prepared, fast spoiled gradient/recall in the steady state scan of the whole brain that used 1.5-mm contiguous sections was performed to acquire a T(1)-weighted data set. Human ratings of volumetric measurement of brain structures were performed with stereological techniques on three-dimensional reconstructed MRIs.

RESULTS

The patient group had significant deficits in cortical gray matter, temporal lobe gray matter, and whole brain volume as well as significant enlargement of the lateral and third ventricles. Structural deviations were found in both treatment-naive and minimally treated subjects. No relationships were found between any brain matter volumes and positive or negative symptoms.

CONCLUSIONS

Structural brain abnormalities were distributed throughout the cortex with particular decrement evident in gray matter. This feature is consistent with altered cell structure and disturbed neuronal connectivity, which accounts for the functional abnormality of psychosis.

Prolonged reaction time to a verbal working memory task predicts increased power of posterior parietal cortical activation

We used multislice functional magnetic resonance imaging (fMRI) to investigate the association between behavioral and neurophysiological measures of working memory task performance in 20 right-handed male healthy volunteers. Images were acquired over a 5-min period at 1.5 Tesla. We used a periodic design, alternating 30-s blocks of the "n-back" working memory task with 30-s blocks of a sensorimotor control task to activate verbal working memory systems. The power of functional response to the task was estimated by sinusoidal regression at each voxel. The relationship between power of fMRI response and mean reaction time over all 11 working memory trials was explored by multiple regression, with age and mean reaction time to the control task as covariates, at voxel and regional levels of analysis. All subjects were able to perform the n-back task accurately. A spatially distributed network was activated, including dorsolateral prefrontal cortex, inferior frontal gyrus, lateral premotor cortex, and supplementary motor area (SMA) in the frontal lobes. More posteriorly, there were major foci of activation in parietal and occipitoparietal cortex, precuneus, lingual, and fusiform gyri of the ventral occipital lobe, inferior temporal gyrus, and cerebellum. The power of functional response was positively correlated with reaction time in bilateral posterior parietal cortex (Talairach coordinates in x, y, z (mm) 35, -44, 37 and -32, -56, 42), indicating that subjects who found the task difficult, and responded with a slower reaction time, tended to activate these regions more powerfully. One interpretation of this regionally specific relationship between prolonged reaction time and increased power of posterior parietal activation is consistent with prior studies identifying similar areas of parietal cortex as the site of the phonological storage function in verbal working memory.

Unusual chromosomal organization of telomeric sequences and expeditious karyotypic differentiation in the recently evolved Mus terricolor complex

The Mus terricolor complex displays a stable homozygous arrangement of autosomal heterochromatin variations in the form of accretion of definitive autosomal short arms among three nonoverlapping populations, in concert with an expeditious evolutionary differentiation into three chromosomal species: M. terricolor I, II, and III. In contrast to the highly conservative M. musculus-like chromosomes in the coexisting sibling species, M. booduga, reshuffling and differentiation of centric heterochromatin has occurred in harmony with a revision of centric configurations, resulting in acrocentric and submetacentric autosomes. The chromosomal distribution of the prevalent vertebrate telomeric sequence (TTAGGG)n was examined by fluorescence in situ hybridization to metaphase cells of M. terricolor I, II, and III. An unusual centric organization of internal telomeric sequences was detected in all the submetacentric and acrocentric autosomes. An auxiliary role of these presumably fragile, recombinogenic telomeric sequences in the evolutionary revision of centric configurations in the terricolor complex is hypothesized.

Third ventricle enlargement and developmental delay in first-episode psychosis: preliminary findings

BACKGROUND

Third rather than lateral ventriculomegaly may be a more specific finding in psychosis. The relevance of ventricular abnormality remains unclear.

AIMS

To investigate the developmental correlates of ventricular enlargement.

METHOD

Information on childhood development and magnetic resonance images in 1.5-mm contiguous sections were collected on 21 patients experiencing a first episode of psychosis.

RESULTS

Patients (n = 21) had significantly less whole brain volume and enlarged third and lateral ventricles compared to controls (n = 25). Third ventricle (r = 0.48, P < 0.03) and lateral ventricle (r = 0.65, P < 0.01) volumes correlated with developmental score. Patients with developmental delay had significantly larger third and lateral ventricles than those without.

CONCLUSIONS

Enlargement of both third and lateral ventricles is found in first-episode psychosis and is related to developmental delay in childhood. Insult to periventricular areas is relevant to the neurobiology of the disease. These findings support the view that schizophrenia involves disturbance of neurodevelopmental processes in some patients.

Ultrasound biomicroscopy of sclerotomy sites after pars plana vitrectomy for diabetic vitreous hemorrhage

OBJECTIVE

This study was aimed at assessing changes at the sclerotomy site using the ultrasound biomicroscope (UBM) in eyes that underwent primary pars plana vitrectomy for complications of proliferative diabetic retinopathy.

DESIGN

Prospective, observational case series.

PARTICIPANTS

Eighty-six eyes of 84 patients with vitreous hemorrhage caused by proliferative diabetic retinopathy.

INTERVENTION

Three-port pars plana vitrectomy followed by UBM evaluation of all sclerotomy sites between 6 and 8 weeks after surgery. Correlation with intraoperative findings done in case of reoperations. Forty-one eyes had repeat UBM at 6 months.

MAIN OUTCOME MEASURES

The changes at the sclerotomy site were classified into six groups: well healed, gape, plaque, vitreous incarceration, fibrovascular proliferation, and anterior hyaloidal fibrovascular proliferation (AHFVP). The UBM characteristics of each of the groups were defined. The findings at 6 months were compared with those at 6 to 8 weeks.

RESULTS

At 6 to 8 weeks after surgery, most sclerotomies were well healed or had either moderate to high reflective plaques bridging the site. Wound gape was seen in 22.1% of active ports, 32.6% of light ports, and 25.6% of infusion ports. Vitreous incarceration was seen most often at the infusion port (18. 6% of eyes). Fibrovascular proliferation was seen in 9.3% of active ports, 12.8% of light ports, and 15.1% of infusion ports. Thirteen eyes had recurrent vitreous hemorrhage 6 to 8 weeks after surgery. Cases with rebleeding and no fibrovascular proliferation at the sclerotomy on UBM did well with outpatient fluid-air exchange (two eyes) or observation only (three eyes). Those with fibrovascular proliferation on UBM (eight eyes) required more extensive surgery.

CONCLUSIONS

UBM is helpful in detecting complications at the sclerotomy sites after pars plana vitrectomy and is an invaluable tool in the assessment of the patient before reoperation.

Audit of small-incision cataract surgery using an anterior chamber maintainer

PURPOSE

To assess the results of small-incision cataract surgery with intraocular lens implantation using an anterior chamber maintainer (ACM) performed between March 1997 and December 1998.

METHOD

A retrospective audit was performed of all 300 consecutive patients who underwent extracapsular cataract extraction using a 6 mm scleral tunnel incision, anterior chamber maintainer and manual fragmentation of the nucleus.

RESULTS

Ninety per cent of patients had a gain in visual acuity at the end of 3 months. The rate of posterior capsule opacification was comparable to the results of the National Cataract Surgery Survey (RCO 1993), i.e. 13%, but the rate of corneal endothelial decompensation and endophthalmitis was marginally higher.

CONCLUSION

Appropriate selection of cases, meticulous wound closure and subconjunctival antibiotics at the end of surgery make this an acceptable alternative small-incision closed-system low-cost procedure where phacoemulsification is not available.

Ultrasound biomicroscopy in the diagnosis and management of pars planitis caused by caterpillar hairs

PURPOSE

To report the use of ultrasound biomicroscopy in the detection of caterpillar hairs in the pars plana in a patient with unilateral pars planitis.

METHOD

Ultrasound biomicroscopic imaging of the anterior segment of the eye.

RESULTS

Ultrasound biomicroscopy located a hair in the posterior chamber at the first visit and five more in the pars plana 1 month later. This finding was confirmed intraoperatively.

CONCLUSION

Ultrasound biomicroscopy is useful in the diagnosis and management of unilateral pars planitis of uncertain cause.

The relevance of ethnic influences on pharmacogenetics to the treatment of psychosis

Interethnic variation amongst the drug metabolising enzymes relevant to the treatment of psychosis is reviewed. The frequency of genetically determined variants at the extremes of enzyme activity is seen to vary considerably between different ethnic groups; in addition, a shift in the frequency distribution giving an overall lower population mean activity may occur. The role of dietary and other environmental influences in the generation of interethnic variation in cytochrome activity is also discussed. Clinical studies pertinent to this variation are reviewed. It is suggested that the reason for conflicting data from some clinical studies is the existence of overlapping substrate specificity, so that one cytochrome is able to substitute for another. Individuals deficient for more than one cytochrome would be likely to show much more pronounced clinical effects than those showing single cytochrome deficiency.

Albendazole therapy for a recurrent orbital hydatid cyst

Till recently, the treatment of a multiloculated hydatid cyst in the confines of the orbit was every ophthalmologist's nightmare. Over the last decade, two benzimidazole compounds, mebendazole and albendazole, have been tested clinically for use in the chemotherapy of hydatid disease.

Surgery for stage 5 retinopathy of prematurity: the learning curve and evolving technique

PURPOSE

To describe our experience with management of eyes with stage 5 retinopathy of prematurity (ROP).

METHODS

Closed vitreoretinal surgery was done on 96 eyes of patients with stage 5 ROP. Lens was sacrificed in all but one eye. Surgery involved an attempt to clear all preretinal tissue and open the peripheral trough all round. In most instances bimanual surgery under viscoelastic was performed.

RESULTS

At last follow up, anatomical success (defined as attached posterior pole) was achieved in 22.5% cases. Significant postoperative problems included reproliferation and secondary glaucoma. Only two infants obtained mobile vision.

CONCLUSION

Late identification of disease, lack of prior treatment such as laser or cryo, and higher incidence of narrow-narrow funnel configuration were responsible for the poor surgical results noted in this series. The poor surgical and functional results reemphasize the need for prompt screening and management of infants at risk.

Prepulse inhibition of the startle response in men with schizophrenia: effects of age of onset of illness, symptoms, and medication

BACKGROUND

Prepulse inhibition of the startle reflex response refers to the ability of a weak prestimulus to transiently inhibit the response to a closely following strong sensory stimulus. This effect represents an operational index of sensorimotor gating and is found to be deficient in schizophrenia. Prepulse inhibition deficits in schizophrenia seem to be partially normalized by typical antipsychotics and more fully by some atypical antipsychotics. Early onset of schizophrenia, particularly in men, has been associated with abnormal brain maturation, profound neuropsychological deficits, and less responsiveness to antipsychotic medication. We evaluated the effects of the age of onset of illness, current positive and negative symptoms, and the type of medication (typical vs atypical) on prepulse inhibition of the startle response in schizophrenia.

METHODS

Thirty-eight male schizophrenic patients and 20 healthy male controls underwent testing for prepulse inhibition of the acoustic startle response.

RESULTS

Earlier onset of illness was associated with reduced prepulse inhibition, while adult onset of illness was not. No significant relationships occurred between current symptoms and prepulse inhibition. Patients given typical, but not atypical, antipsychotics exhibited less prepulse inhibition compared with healthy controls.

CONCLUSION

Early onset of illness is associated with profound deficits in prepulse inhibition of the startle response in men with schizophrenia.