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Dive into the research topics where Gerhard P. Jordaan is active.

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Featured researches published by Gerhard P. Jordaan.


American Journal of Sports Medicine | 1990

Prevention of common overuse injuries by the use of shock absorbing insoles A prospective study

Martin P. Schwellnus; Gerhard P. Jordaan; Timothy D. Noakes

Sedentary individuals, particularly new military recruits, who start a physical training program have a substantial risk of developing an overuse injury of the lower limb. In this study we investigated the effect of neoprene insoles on the incidence of overuse injuries during 9 weeks of basic military training. The experimental group consisted of 237 randomly selected new recruits, while 1151 recruits were the control group. Insoles were given to the experimental group and compliance was monitored. A panel of doctors documented and classi fied all injuries occurring during the 9 week period. A total of 54 (22.8%) and 237 (31.9%) injuries were reported in the experimental and control groups, re spectively. In both groups, the majority of injuries were overuse (experimental group, 90.7%; control group, 86.4%). The mean weekly incidence of total overuse injuries and tibial stress syndrome was significantly lower (P < 0.05) in the experimental group. The mean incidence of stress fractures was lower in the experimental group but not significantly so (0.05 < P < 0.1). This study shows that the incidence of total overuse injuries and tibial stress syndrome during 9 weeks of basic military training can be reduced by wearing insoles.


Progress in Neuro-psychopharmacology & Biological Psychiatry | 2008

Resting brain perfusion in social anxiety disorder : A voxel-wise whole brain comparison with healthy control subjects

James Warwick; P Carey; Gerhard P. Jordaan; Patrick Dupont; Dan J. Stein

INTRODUCTION Social anxiety disorder (SAD) is a condition characterised by fears of social interaction and performance situations. SAD may be related to a dysregulation or hyperactivity of cortico-limbic circuitry. This is the first voxel-based whole brain study comparing resting function in SAD to a normal control group. METHODS Resting perfusion in adult subjects with generalised SAD was compared with healthy adult volunteers using Statistical Parametric Mapping (SPM). In subjects with SAD, correlations were also sought between resting perfusion and clinical severity measured using the total Liebowitz Social Anxiety Scale (LSAS). RESULTS Twenty-eight subjects with SAD were compared with 19 healthy volunteers. SAD subjects had increased resting perfusion in the frontal cortex and right cerebellum, and decreased perfusion in the pons, left cerebellum, and right precuneus. Total LSAS correlated positively with left frontal cortex resting perfusion, and negatively with right fusiform and right lingual perfusion. CONCLUSION This study demonstrated increased resting frontal function in social anxiety disorder that is consistent with its hypothesised role in the modulation of excessive limbic activity in anxiety disorders. The correlation of posterior cortical resting function with the severity of SAD symptoms may point to defective perception of self and others.


Metabolic Brain Disease | 2014

Alcohol-induced psychotic disorder: a review

Gerhard P. Jordaan; Robin Emsley

While alcohol-induced psychotic disorder (AIPD) is well recognised, relatively little is known about the condition. We undertook a review of the literature to identify studies on the epidemiology, clinical manifestations, underlying neurobiology and treatment of AIPD. Few prospective studies have been conducted on AIPD. Recent advances have focussed on epidemiological, phenomenological, neuro-imaging, treatment and outcome issues. Current evidence suggests AIPD can be clinically distinguished from alcohol-withdrawal delirium and schizophrenia. The disorder may be more common than previously recognised depending on the inclusion criteria applied. AIPD is associated with high co-morbidity with other psychiatric disorders, high re-hospitalization and mortality rates and suicidal behaviour. Concurrent dysregulation of several neurotransmitter systems may be involved in the pathogenesis of hallucinations in alcohol dependence, and neuro-imaging studies suggest perfusion abnormalities to various brain regions. Antipsychotic treatment remains the preferred treatment for AIPD. The prognosis appears less favourable than previously believed, yet usually good when abstinence can be maintained.


BMC Psychiatry | 2013

A clinical approach to the assessment and management of co-morbid eating disorders and substance use disorders.

Claire Gregorowski; Soraya Seedat; Gerhard P. Jordaan

IntroductionResearch has shown that eating disorder (ED) patients who abuse substances demonstrate worse ED symptomatology and poorer outcomes than those with EDs alone, including increased general medical complications and psychopathology, longer recovery times, poorer functional outcomes and higher relapse rates. This article provides a broad overview of the prevalence, aetiology, assessment and management of co-morbid EDs and substance use disorders (SUDs).ReviewThe co-occurrence of EDs and SUDs is high. The functional relationship between EDs and SUDs vary within and across ED subtypes, depends on the class of substance, and needs to be carefully assessed for each patient. Substances such as caffeine, tobacco, insulin, thyroid medications, stimulants or over the counter medications (laxatives, diuretics) may be used to aid weight loss and/or provide energy, and alcohol or psychoactive substances could be used for emotional regulation or as part of a pattern of impulsive behaviour. A key message conveyed in the current literature is the importance of screening and assessment for co-morbid SUDs and EDs in patients presenting with either disorder. There is a paucity of treatment studies on the management of co-occurring EDs and SUDs. Overall, the literature indicates that the ED and SUD should be addressed simultaneously using a multi-disciplinary approach. The need for medical stabilization, hospitalization or inpatient treatment needs to be assessed based on general medical and psychiatric considerations. Common features across therapeutic interventions include psycho-education about the aetiological commonalities, risks and sequelae of concurrent ED behaviours and substance abuse, dietary education and planning, cognitive challenging of eating disordered attitudes and beliefs, building of skills and coping mechanisms, addressing obstacles to improvement and the prevention of relapse. Emphasis should be placed on building a collaborative therapeutic relationship and avoiding power struggles. Cognitive behavioural therapy has been frequently used in the treatment of co-morbid EDs and SUDs, however there are no randomized controlled trials. More recently evidence has been found for the efficacy of dialectical behavioural therapy in reducing both ED and substance use behaviours.ConclusionFuture research would benefit from a meta-analysis of the current research in order to better understand the relationships between these two commonly co-occurring disorders.


Progress in Neuro-psychopharmacology & Biological Psychiatry | 2010

Resting brain perfusion in alcohol-induced psychotic disorder: A comparison in patients with alcohol dependence, schizophrenia and healthy controls

Gerhard P. Jordaan; James Warwick; Richard H. Hewlett; Robin Emsley

INTRODUCTION Alcohol-induced psychotic disorder (AIPD), also known as alcohol hallucinosis, is a rare complication of alcohol abuse. The underlying pathophysiology is poorly understood, and the disorder needs to be differentiated from alcohol withdrawal delirium and schizophrenia. No brain-imaging studies in AIPD have been reported to date. Case reports of brain imaging in AIPD suggest possible dysfunction in the thalamus, basal ganglia, frontal lobes and cerebellum. Our aim was to prospectively compare resting brain perfusion (rCBF) in patients with AIPD, uncomplicated alcohol dependence, schizophrenia and healthy volunteers. METHODS Single photon emission computed tomography (SPECT) was utilized to compare rCBF in patients with AIPD (n=19), schizophrenia (n=16), uncomplicated alcohol dependence (n=20) and healthy volunteers (n=19). RESULTS Increased rCBF was demonstrated in the right calcarine area in patients with AIPD compared to healthy volunteers, with a trend towards increased rCBF to the frontal and temporal lobes and the right pallidum. Decreased left sided rCBF to the putamen, parietal, mid-frontal and mid-temporal lobes and heterogenous flow to the cerebellum were demonstrated in patients with AIPD when compared to patients with uncomplicated alcohol dependence. The left posterior cingulate and right cerebellum showed higher and lower rCBF respectively in patients with AIPD compared to patients with schizophrenia. CONCLUSION Our findings implicate the right occipital lobe and possibly the cerebellum in the pathogenesis of AIPD and have similarities with those previously reported in alcohol withdrawal. Reduced rCBF to the frontal lobes, thalamus and basal ganglia in AIPD as suggested in previous case reports could not be confirmed.


Psychiatry Research-neuroimaging | 2016

Resting functional connectivity in social anxiety disorder and the effect of pharmacotherapy

Alexander Doruyter; Christine Lochner; Gerhard P. Jordaan; Dan J. Stein; Patrick Dupont; James Warwick

Neuroimaging research has reported differences in resting-state functional connectivity (RFC) between social anxiety disorder (SAD) patients and healthy controls (HCs). Limited research has examined the effect of treatment on RFC in SAD. We performed a study to identify differences in RFC between SAD and HC groups, and to investigate the effect of pharmacotherapy on RFC in SAD. Seed-based RFC analysis was performed on technetium-99m hexamethylpropylene amine oxime (Tc-99m HMPAO) SPECT scans using a cross-subject approach in SPM-12. Seeds were chosen to represent regions in a recently published network model of SAD. A second-level regression analysis was performed to further characterize the underlying relationships identified in the group contrasts. Twenty-three SAD participants were included, of which 18 underwent follow-up measures after an 8-week course of citalopram or moclobemide. Fifteen healthy control (HC) scans were included. SAD participants at baseline demonstrated several significant connectivity disturbances consistent with the existing network model as well as one previously unreported finding (increased connectivity between cerebellum and posterior cingulate cortex). After therapy, the SAD group demonstrated significant increases in connectivity with dorsal anterior cingulate cortex which may explain therapy-induced modifications in how SAD sufferers interpret emotions in others and improvements in self-related and emotional processing.


International Journal of Eating Disorders | 1996

Serotonergic agents in the treatment of hypothalamic obesity syndrome: A case report

Gerhard P. Jordaan; Mimi C. Roberts; Robin Emsley

The hypothalamic obesity syndrome is characterized by hyperphagia and excessive weight gain in the presence of demonstrable hypothalamic injury. There have been no previous reports describing the use of serotonergic agents in this condition. We report on a patient with severe hyperphagia and obesity secondary to a hypothalamic lesion, who was treated with consecutive courses of fluoxetine and fenfluramine. Neither treatment resulted in a reduction in food intake or weight. Treatment of hypothalamic obesity with serotonergic agents appears to be of little value, probably because they exert their effect via intact serotonergic-sensitive hypothalamic nuclei.


South African Medical Journal | 2017

Junior medical students’ knowledge about and attitudes towards electroconvulsive therapy in a South African setting

Matthew B. Mausling; Muiruri Macharia; Gerhard P. Jordaan

Background Although electroconvulsive therapy (ECT) is a safe and effective treatment modality with a long history of use in psychiatry, it remains controversial owing to misconceptions and negative attitudes among the public and medical profession. The aim of this study was to explore the state of knowledge and attitudes towards ECT among a sample of South African medical students. Method Prior to their theoretical psychiatry module, 131 second-year medical students responded to an anonymous online survey designed to assess the source and extent of their ECT knowledge as well as their attitude towards ECT and psychiatry in general. Results The Internet (46.6%) and TV and/or movies (30.5%) were the principal sources of knowledge of ECT while ‘professional publication’ was the least common (0%). The students’ attitudes towards psychiatry were generally positive and nearly one-third (29.8%) would consider specialising in the field. Overall, perception towards ECT was mixed, with many respondents approving of its use albeit only as a last resort. Notably, low ECT knowledge scores were associated with more negative attitudes towards this treatment modality and a lower perception of psychiatry as a medical speciality. Conclusion The findings indicate that for these students, media is the main source of ECT knowledge. While they are generally knowledgeable about ECT, they still harbour some misconceptions and negative attitudes about the treatment. Knowledge appears able to amend these attitudes, thus underlining the importance of integrating accurate information about ECT into the preclinical medical curriculum rather than leaving it to mass media to forge warped perceptions and attitudes for these future clinicians.


Journal of Child & Adolescent Mental Health | 2014

The psychopharmacological management of eating disorders in children and adolescents

Leigh van den Heuvel; Gerhard P. Jordaan

In this review we synthesised current literature on the psychopharmacological management of eating disorders (EDs) in children and adolescents (C&As). We focus specifically on anorexia nervosa (AN), bulimia nervosa (BN) and binge eating disorder (BED). The treatment of EDs is determined by physical and psycho-social factors and needs. Pharmacological management should therefore be viewed and incorporated as one component of a multi-disciplinary comprehensive treatment plan for specific requirements of a patient depending on the stage of the disorder. As there is a dearth of studies evaluating the use of psychopharmacology for EDs in C&As we first review the findings from studies performed in adults and then discuss specific studies performed in C&As. We include information from reviews and treatment guidelines to assist the clinician with an approach to the use of psychopharmacological agents in the treatment of EDs in C&As.


Military Medicine | 1994

The incidence of overuse injuries in military recruits during basic military training.

Gerhard P. Jordaan; Martin P. Schwellnus

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Robin Emsley

Stellenbosch University

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Dan J. Stein

University of Cape Town

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Daan Nel

Stellenbosch University

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Helen Clark

Chris Hani Baragwanath Hospital

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Patrick Dupont

Katholieke Universiteit Leuven

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