Measuring impulsivity in Parkinson's disease: a correlational and structural neuroimaging study using different tests

BACKGROUND AND PURPOSE

Impulsivity is an aspect of personality and a major component of multiple neuropsychiatric conditions. In Parkinson's disease, it has been associated with the expression of impulse control disorders, a highly prevalent non-motor complication. Even though multiple tests of impulsivity have been used in this context, the impact of test choice has not been addressed. The aim was to evaluate whether different impulsivity measures in Parkinson's disease share substantial inter-scale and anatomical correlations or rather mirror different underlying phenomena.

METHODS

In a consecutive sample of 89 Parkinson's disease patients without impulse control disorders, four common tests were evaluated assessing different aspects of impulsivity: impulsiveness trait, decisions under implicit risk with and without losses, and delay discounting. Correlations among test scores were analysed and each score was used as a regressor in a set of grey matter volume (GMV) voxel-based morphometry analyses to explore their brain structural correlates.

RESULTS

No significant correlations were found between the different impulsivity tests. Furthermore, their structural brain correlates were divergent. Impulsiveness trait appeared to be associated with lower GMV in dorsal-lateral prefrontal cortices, implicit risk (with losses) with higher GMV in the left nucleus accumbens and lower left insular GMV, implicit risk (without losses) with higher GMV in the left lingual gyrus and lower GMV in the gyri recti and delay discounting with higher GMV in the left nucleus accumbens.

CONCLUSIONS

In Parkinson's disease, different impulsivity measures reflect very dissimilar behavioural and brain structural correlates. Our results suggest that parkinsonian impulsivity is not a unitary phenomenon but rather a heterogeneous entity.

[Movement disorders units and management of motor fluctuations in advanced Parkinson's disease]

INTRODUCTION

Advanced Parkinson's disease (PD) entails complications, such as motor fluctuations. In Spain, medical attention for such cases is often provided in movement disorder units (MDU).

AIM

To gain further knowledge of the diagnostic resources and therapeutic approach of MDU.

SUBJECTS AND METHODS

A descriptive cross-sectional study was conducted. The researchers designed an on-line questionnaire, addressed to neurologists from MDUs, containing 48 questions about the resources they have available, the number of patients with PD and motor fluctuations that have been attended to, as well as the therapeutic approach, according to the Hoehn and Yahr (HY) scale.

RESULTS

Fifty-five neurologists participated. Structural neuroimaging is available to 100% of them; 89% have access to functional neuroimaging; 89% have acute pharmacological tests available for use; 78% have access to genetic tests; and 53% have transcranial ultrasound at their disposal. There are 2.5 neurologists and 1.2 nurses per unit. Of the patients with PD that they see, 19% of them are in HY stage 1, 59% are in HY stage 2-3 and 22% are in HY stage 4-5. Treatment consists, first of all, in monoamine oxidase type B inhibitors in HY stages 1 and 2, and levodopa in HY stages 3, 4 and 5. Twenty-four per cent of the patients have motor fluctuations, with 5.5 off episodes per day, lasting 44 minutes, with a total of seven off hours per day. Fourteen per cent of the patients under 70 years of age with more than three long-term off episodes per day are receiving invasive treatment for motor fluctuations.

CONCLUSIONS

MDUs are well equipped with diagnostic and pharmacological resources. Pharmacological treatments are tailored to each patient with a wide range of combinations. Despite this optimisation, the prevalence of motor fluctuations is still high in advanced patients, and invasive therapies may be underused.

Visual hallucinations in patients with acute stroke: a prospective exploratory study

BACKGROUND AND PURPOSE

The incidence, underlying physiopathology, features and association with lesion topography of visual hallucinations in acute stroke have scarcely been investigated.

METHODS

Patients with a diagnosis of acute stroke (ischaemic or haemorrhagic) in any vascular territory, admitted within 24 h after the onset of symptoms, were consecutively included in the study. Patients with a previous history of psychosis or cognitive impairment were excluded. They and/or their caregivers answered a structured hallucination and sleep questionnaire at admission, within the first 15 days and at the clinical follow-up 3-6 months after discharge. Lesion location (IMAIOS online atlas) and leukoaraiosis (Wahlund scale) were determined by magnetic resonance imaging or computed tomography scan. Subsets of patients also underwent a neuropsychological evaluation (N = 50) and an electroencephalogram (N = 33) before discharge.

RESULTS

In all, 77 patients with a mean age of 71 ± 12 years were included of whom 57.1% were men. The incidence of visual hallucinations was 16.7%. These hallucinations were mostly complex, in black and white and self-limited. The appearance of hallucinations was not influenced by age, sex, neuropsychological performance during admission or modified Rankin scale score at discharge. Visual hallucinations were associated with occipital cortex lesions (P = 0.04), and with sleep disturbances during and before admission (P = 0.041 and P = 0.03 respectively).

CONCLUSIONS

Visual hallucinations are relatively frequent in patients with acute stroke and they are self-limited. Patients with occipital lesions and sleep disturbances are more likely to suffer them.

[The essence of essential tremor: neurochemical bases]

INTRODUCTION

Essential tremor is the most frequent movement disorder in adults. It has been considered a benign disease, but can result in significant physical and psychosocial disability. Pharmacological treatment is still not very satisfactory. Its causation, pathophysiology and anatomy remain only partially understood.

AIMS

An understanding of its neurochemical basis is essential to be able to develop more efficient therapies. We review what is currently known in this field in order to motivate further research and ideas that allow an enhanced understanding of the disease and which foster the development of new pharmacological therapies.

DEVELOPMENT

We review the studies conducted to date in humans and in animal models of neurotransmitters (gamma-aminobutyric acid, glutamate, noradrenalin, serotonin, adenosine), proteins and other neurochemical phenomena, such as T-type calcium channels, in essential tremor.

CONCLUSIONS

Four neurochemical dysfunctions have been described that basically occur in the cerebellum and the inferior olivary nucleus: alteration of the GABAergic system, increased post-inhibitory rebound via T-type calcium currents, decreased neuronal inhibition mechanisms and an increase in excitatory neurotransmitter activity. These neurochemical dysfunctions would involve an increase in the activity of the deep neurons of the cerebellum with an oscillatory activity that would shift to the thalamic nucleus and the motor cortex, which in turn would lead to the appearance of tremor. Further research is needed to be able to confirm these hypotheses and to continue to advance towards achieving more efficient pharmacological treatments for patients with essential tremor.

Fused in Sarcoma (FUS) gene mutations are not a frequent cause of essential tremor in Europeans

FUS/TLS (denoting fused in sarcoma/translocated in liposarcoma [MIM 137070]) codifies an RNA binding protein. Mutations in this gene cause amyotrophic lateral sclerosis (ALS; MIM 608030). Essential tremor (ET [MIM 190300]) is the most frequent movement disorder. Despite its strong familiar aggregation, recently a whole exome sequencing study has identified FUS mutations as a cause of familial ET. To determine whether mutations in FUS are also common in other populations, we sequenced FUS gene in 178 unrelated Spanish subjects with ET. We detected only an intronic single-pair nucleotide deletion (c.1293-37delC), which was predicted to affect mRNA splicing. However, leukocyte mRNA analysis showed no changes in FUS expression. In conclusion, coding or splicing FUS mutations are not a frequent cause of ET in the Spanish population.

Gaba and serotonin molecular neuroimaging in essential tremor: a clinical correlation study

BACKGROUND

Essential tremor is the most common movement disorder in adults, but its exact etiology and pathophysiology are still not fully understood. There is some consensus, however, about the involvement of the cerebellum and accumulating evidence points towards a dysfunction of the gabaergic system. We hypothesize that the serotonin neurotransmission system may also play a role as it does in tremor in Parkinson disease. This study aimed to investigate the association between the severity of tremor symptoms and the gabaergic and serotoninergic neurotransmission systems in essential tremor.

MATERIAL AND METHODS

We measured the tremor clinical rating scale score and acquired DASB and Flumazenil PET scans in 10 patients who presented with essential tremor at different stages of clinical severity. Statistically significant correlations were sought between the scale scores and parametric binding potential images.

RESULTS

The correlation analysis of cerebellar Flumazenil uptake and tremor clinical rating scale scores reached statistical significance (R2 = 0.423, p = 0.041), whereas no association was detected in the DASB scans.

CONCLUSIONS

The severity of tremor correlated with the abnormalities found in GABA receptor binding, suggesting a primary gabaergic deficiency or a functional abnormality at the level of GABA(A) receptor subtypes. These results may assist in the rational development of new pharmacological treatments for essential tremor.

Motor changes during sertraline treatment in depressed patients with Parkinson's disease*

BACKGROUND

Pharmacological interventions to treat depressive symptoms associated with Parkinson's disease (PD) are limited. Whether selective serotonine re-uptake inhibitors increase parkinsonism or have clinically significant interactions with antiparkinsonian drugs is unresolved.

PURPOSE

We used a naturalistic approach to prospectively investigate the long-term effects on motor status of adding sertraline in a large sample of community-dwelling PD patients with depressive symptoms.

METHODS

Main outcome measure was the motor part of the Unified PD Rating Scale (UPDRS) at baseline and at 1-, 3-, and 6-month follow-up. Secondary measures were the change in antiparkinsonian drugs expressed as total levodopa equivalent dose and the scores of the Hospital Anxiety and Depression Scale (HADS). Of the 374 patients included, 310 (82%) completed the study.

RESULTS

Treatment with sertraline (mean dose 66.0 +/- 29.8 mg) resulted in improvement in all UPDRS domains along with a significant decrease of the HADS scores. A modest but significant increase of the total dose of levodopa, without significant change of total levodopa equivalent dose, was observed. Almost 8% of patients discontinued medication for adverse events, mainly related to the gastrointestinal system.

CONCLUSIONS

Although worsening of tremor was observed in some patients, active management of depression with sertraline appears to have a positive impact on parkinsonism.

Lack of prefrontal repetitive transcranial magnetic stimulation effects in time production processing

The aim of the present study was to determine the effects of high frequency repetitive transcranial magnetic stimulation (rTMS) over different neuroanatomical areas [left and right doroslateral prefrontal cortex (DLPFC) and right cerebellar hemisphere] on time production task. The study was performed in 16 healthy right-handed men with a cross-over, within subject repeated measures design. There were four rTMS conditions: baseline without stimulation, high frequency rTMS over right, left DLPFC and over right cerebellum. The volunteers were asked to produce a 3-min interval by internal counting. The rTMS was applied during the task. No significantly differences were observed in absolute error scores in time estimation task with any rTMS condition. This preliminary study does not support the role of the prefrontal lobe in time production processes.

Bilateral deep brain stimulation in Parkinson's disease: a multicentre study with 4 years follow-up

Deep brain stimulation (DBS) is associated with significant improvement of motor complications in patients with severe Parkinson's disease after some 6-12 months of treatment. Long-term results in a large number of patients have been reported only from a single study centre. We report 69 Parkinson's disease patients treated with bilateral DBS of the subthalamic nucleus (STN, n = 49) or globus pallidus internus (GPi, n = 20) included in a multicentre study. Patients were assessed preoperatively and at 1 year and 3-4 years after surgery. The primary outcome measure was the change in the 'off' medication score of the Unified Parkinson's Disease Rating Scale motor part (UPDRS-III) at 3-4 years. Stimulation of the STN or GPi induced a significant improvement (50 and 39%; P < 0.0001) of the 'off' medication UPDRS-III score at 3-4 years with respect to baseline. Stimulation improved cardinal features and activities of daily living (ADL) (P < 0.0001 and P < 0.02 for STN and GPi, respectively) and prolonged the 'on' time spent with good mobility without dyskinesias (P < 0.00001). Daily dosage of levodopa was significantly reduced (35%) in the STN-treated group only (P < 0.001). Comparison of the improvement induced by stimulation at 1 year with 3-4 years showed a significant worsening in the 'on' medication motor states of the UPDRS-III, ADL and gait in both STN and GPi groups, and speech and postural stability in the STN-treated group. Adverse events (AEs) included cognitive decline, speech difficulty, instability, gait disorders and depression. These were more common in patients treated with DBS of the STN. No patient abandoned treatment as a result of these side effects. This experience, which represents the first multicentre study assessing the long-term efficacy of either STN or GPi stimulation, shows a significant and substantial clinically important therapeutic benefit for at least 3-4 years in a large cohort of patients with severe Parkinson's disease.

[Cognitive and functional decline in the stage previous to the diagnosis of Alzheimers disease]

INTRODUCTION

The decline in the phase prior to diagnosis of Alzheimers disease (AD) is not well known, although this knowledge is necessary to evaluate the efficiency of new drugs that can influence in disease course prior to diagnosis.

OBJECTIVE

To contribute to better knowledge of the decline prior to diagnosis, we have investigated the cognitive and functional deterioration for 2-3 years before the probable AD diagnosis was established.

PATIENTS AND METHODS

We compared results obtained by 17 control subjects and 27 patients at the time of diagnosis of a probable AD with results obtained 2-3 years before (interval of 27.7 4 months). We compared memory functions (logical, recognition, learning and autobiographical memory), naming, visual and visuospatial gnosis, visuoconstructive praxis, verbal fluency and the Mini-Mental State Examination (MMSE), Informant Questionnaire and Blessed's Scale scores.

RESULTS

Performance of control subjects did not change. AD patients showed a significant decline in scores, except for verbal fluency. In order of importance, cognitive decline was more marked in scores of learning memory, visuospatial gnosis, autobiographical memory and visuoconstructive praxis.

CONCLUSIONS

Decline prior to diagnosis of AD is characterized by an important learning memory impairment. Deterioration of visuospatial gnosis and visuoconstructive praxis is greater than deterioration of MMSE and Informant Questionnaire scores.

[Validation of the translation to Catalan and Spanish of cognitive evoked potential N400]

INTRODUCTION

The cognitive evoked potential N400 permits an objective assessment of the verbal semantic processing. It has been suspected to be clinically useful in cognitive abnormalities and a correlation with attentional and memory functions has been found. The present study tries to validate the translation and adaptation of the English paradigm to the Catalan and Spanish languages.

METHOD

The study was performed on 16 healthy volunteers with Catalan native language and 16 volunteers with Spanish native language. Three blocks of 50 sentences (4-9 words) were administered using headphones. The last word of 50 % of the sentences was incongruent. The beginning of this word was the trigger for the EEG average. EEG leads used were: Fz, Cz, Pz, C3, C4, T3, T4 with biauricular reference. The measures were amplitude and latency of the potential obtained after the subtraction of the EEG average of congruent and incongruent sentences. A t-test for one sample (the original potential) was applied.

RESULTS

Amplitude and latency of the potential obtained by the Catalan and Spanish languages were not result statistically different from the original potential. The major amplitude was obtained in Cz. Mean amplitudes: Catalan language: 5.3 2.3 V (95 % CI for the difference: 0.39 2.12 V); Spanish language: 5.2 2.3 V (95 % CI for the difference: 0.43 2.32 V).

CONCLUSIONS

The Catalan and Spanish version of the N400 evoked potential offer the possibility to use an objective instrument for the study of language in neuroscience.

[Sustained attention in the preclinical phase of Alzheimer's disease]

INTRODUCTION

Deterioration of attention in the preclinical phase of dementia of Alzheimer s type (DAT) is not very well known neither available studies are conclusive.

OBJECTIVE

We outline if would be possible to identify a deficit of sustained attention in preclinical phase of DAT and if this attentional dysfunction could help to identify those patients, referred by subjective memory complaints (SMC), who will progress in a few years to DAT.

PATIENTS AND METHODS

We compared basal exploration in a task of sustained attention (CPT) of 70 patients referred by SMC and followed longitudinally for 2 years. Twenty seven patients developed probable DAT and forty three remained clinically stable.

RESULTS

Patients who will be diagnosed 2 years later with DAT performed significantly more poorly than patients who did not develop DAT. Patients who will be diagnosed 2 years later with DAT made a higher number of omission errors and obtained a lower number of correct responses.

CONCLUSION

CPT paradigm is a vigilance task that detects deterioration of sustained attention in the preclinical phase of DAT and could be an objective indicator of the cognitive decline in the preclinical phase of Alzheimer s disease.

Effects of repetitive transcranial magnetic stimulation on memory subtypes: a controlled study

Repetitive transcranial magnetic stimulation (rTMS) of human cortex may disrupt or facilitate cortical activity. The aim of the present study was to investigate the consequences of rTMS applied over different cortical areas during various memory tasks, measuring immediate, working and episodic verbal memory. The study was performed in 16 right-handed healthy men. A double-blind, cross-over, within-subject repeated measures design was used. There were five rTMS conditions: baseline without stimulation, high frequency (HF) rTMS over right and left dorsolateral prefrontal cortex (DLPFC) and over right cerebellum, and low frequency (LF) parameters over left DLPFC. Digits forwards and backwards and letter-number sequencing of the Wechsler Adults Intelligence Scale (WAIS) were used to assess immediate and working verbal memory, and logical memory of the Rivermead Behavioural Memory Test was used to assess episodic memory encoding. An analysis of variance (ANOVA) for repeated measures in the scores of each memory task according to rTMS conditions was used. Significantly lower scores in the number of memory units of the episodic memory task were observed when rTMS high frequency parameters were applied over left DLPFC (P=0.009). No significant differences were found in the other memory subtype tasks analysed during the different rTMS conditions. These findings provide evidence for the significant role of the left DLPFC in episodic verbal memory processes.

Motor circuitry re-organization after pallidotomy in Parkinson disease: a neurophysiological study of the bereitschaftspotential, contingent negative variation, and N30

The aim of the study was to evaluate the reorganization changes in the motor circuitry of the basal ganglia following unilateral posteroventral pallidotomy in Parkinson disease (PD) patients using neurophysiological paradigms. Eight advanced PD patients received a neurophysiological battery 2 months prior and 6 months after unilateral pallidotomy. Examinations were all performed in the practically defined "off" situation. Bereitschaftspotential (BP) and N30 were recorded for each hand alternately. Contingent negative variation (CNV) was obtained using a visual Go/no-Go paradigm. ANOVAs (electrode position; surgery) were applied for BP and CNV results. N30 data were analyzed using Wilcoxon matched-pair tests. A significant increase in amplitude of the late component (NS') of the BP was evidenced with patient performing with the hand contralateral to pallidotomy. No significant amplitude differences were found in CNV after surgery in any lead, or in any of the time windows tested. A trend toward significance was observed corresponding to a postsurgical numerical increase in amplitude of the N30 peak in the hand contralateral to pallidotomy. These results suggest that neurophysiological changes after pallidotomy are mainly in the last stages of movement preparation and execution.

Mania following deep brain stimulation for Parkinson's disease

Three patients with PD developed manic behavior after bilateral implantation of electrodes for deep-brain stimulation (DBS). Common to all three patients were manic symptoms unremitting after levodopa reduction or stimulation "off," lower electrodes positioning caudal to the subthalamic nucleus area, postoperative DBS with the lower contacts (0) of the quadripolar electrodes, and resolution of the manic episodes coinciding with stimulation through higher contacts.

[Weight gain after functional surgery for Parkinsons disease]

BACKGROUND

The origin of weight gain after functional surgery for Parkinson's disease (PD) is incompletely known. We have done a prospective study to determine the possible causes of weight gain after pallidal and subthalamic surgery.

PATIENTS AND METHOD

Twenty-seven patients were studied (9 unilateral pallidotomy, 9 bilateral deep brain stimulation (DBS) of palidum, and 9 bilateral DBS of suthalamic nucleus) with a follow-up of 12 months. The relationship between weight gain and changes in motor situation, levodopa dosage, dyskinesias, dysphagia and mood state were analyzed. The patients filled a questionnaire about the severity and etiology of weight gain.

RESULTS

Weight gain was noted in 26 patients (mean of 4.7 kg at 12 months). It was found a significant correlation between weight gain and improvement of dyskinesias (AIMS) (r = 0.461; p = 0.023), the scores of the UPDRS part III, (r = 0.479; p = 0.028), and a significant inverse correlation with the pre-operative weight of the patient (r = 0.399; p = 0.050). Weight gain was most pronounced with bilateral than unilateral pallidal surgery (p = 0.021). The majority of patients referred weight gain as an slight adverse event and secondary to the improvement of dyskinesias.

CONCLUSION

Functional surgery for PD, independently of the surgical target, provokes weight gain which is benign in the majority of cases. Reduction of energy expenditure with respect to the pre-operative situation would be the responsible of that phenomenon.

Transcranial magnetic stimulation for treating depression

BACKGROUND

Transcranial magnetic stimulation can either excite or inhibit cortical areas of the brain, depending on whether the speed of the repetitive stimulation is applied at high or low frequencies. It has been used for physiological studies and it has also been proposed as a treatment for depression.

OBJECTIVES

To assess the clinical efficacy and safety of transcranial magnetic stimulation for treating depression.

SEARCH STRATEGY

An electronic search was performed including the Cochrane Collaboration Depression, Neurosis and Anxiety Review Group trials register (last searched June, 2001), the Cochrane Controlled Trials Register (Issue 2, 2001), MEDLINE (1966-2001), EMBASE (1974-2001), PsycLIT (1980-2001), and bibliographies from reviewed articles. Unpublished data and grey literature were searched through personal communications with researchers.

SELECTION CRITERIA

Randomised controlled trials assessing the therapeutic efficacy and safety of transcranial magnetic stimulation for depression.

DATA COLLECTION AND ANALYSIS

All reviewers independently extracted the information and verified it by cross-checking. Disagreements were resolved through discussion. Continuous data: When similar studies were grouped, the overall standardised mean difference was calculated under a fixed effect model weighted by the inverse variance method with 95% confidence intervals. (In the presence of statistical heterogeneity, a random effects model was to be used.)

MAIN RESULTS

Sixteen trials were included in the review and fourteen contained data in a suitable form for quantitative analysis. Most comparisons did not show differences between rTMS and other interventions. No difference was seen between rTMS and sham TMS using the Beck Depression Inventory or the Hamilton Depression Rating Scale, except for one time period (after two weeks of treatment) for left dorsolateral prefrontal cortex and high frequency; and also for right dorsolateral prefrontal cortex and low frequency, both in favour of rTMS and both using the Hamilton scale. Comparison of rTMS (left dorsolateral prefrontal cortex and high frequency) with electroconvulsive therapy showed no difference except for psychotic patients after two weeks treatment, using the Hamilton scale, which indicated that electroconvulsive therapy was more effective than rTMS.

REVIEWER'S CONCLUSIONS

The information in this review suggests that there is no strong evidence for benefit from using transcranial magnetic stimulation to treat depression, although the small sample sizes do not exclude the possibility of benefit.

[Postural tremor: clinical and neurophysiological study in a consecutive series of 300 patients]

BACKGROUND

There are few studies analysing the clinical and neurophysiological characteristics of postural tremor in Spain.

PATIENTS AND METHOD

We studied prospectively 300 consecutive patients referred to a Movement Disorders Section because of postural tremor of the upper limbs. Syndromic diagnosis of postural tremor was made according to clinical criteria with the aid of neurophysiological criteria (accelerometric and EMG data). In patients diagnosed with essential tremor (ET), diagnostic sensitivity studies, correlation studies of clinical and neurophysiological data and multivariate analysis were performed.

RESULTS

Most frequent syndromic diagnoses were ET (77%), parkinsonian postural tremor (10%) and exaggerated physiological tremor (6%). Fifty percent of ET patients reported having affected relatives, and 7% reported that their tremor improved with alcohol. Mostly specific variables for the diagnosis of ET were: affected relatives (77%), cephalic tremor (80%), alcohol improvement (100%), and synchronous EMG pattern (79%). The presence of affected relatives and a synchronous EMG pattern were significant predictive variables on a multivariate analysis. We found a significant correlation between age at time of consulting and frequency (rs = 0.561; p < 0.0005) and amplitude (rs = 0.470; p < 0.0005) of tremor.

CONCLUSIONS

In the present study, ET was the most common cause of reference for postural tremor. Selective clinical data and neurophysiological evaluation are useful for the diagnosis of postural tremor.

SPECT mapping of cerebral activity changes induced by repetitive transcranial magnetic stimulation in depressed patients. A pilot study

Repetitive transcranial magnetic stimulation (rTMS) is being investigated as an alternative treatment for depression. However, little is known about the clinical role and the neurophysiological mechanisms of the action of rTMS in these patients. In this study, 99mTc-HMPAO single photon emission computed tomography (SPECT) was used to map the effects of left dorsolateral prefrontal rTMS on prefrontal activity in seven patients who met DSM-IV criteria for major depression resistant to pharmacological treatment. rTMS consisted of 30 trains of 2-s duration stimuli (20 Hz, 90% of motor threshold), separated by 30-s pauses. Each patient underwent three SPECTs: at baseline; during the first rTMS; and 1 week after 10 daily sessions of rTMS. Regional cerebral blood flow (rCBF) of each cerebral region was normalized to the rCBF value in the cerebellum and relative changes in normalized rCBF were addressed using a region-of-interest analysis. The Hamilton Depression Rating Scale (HDRS) was used for clinical evaluation before and after rTMS. A significant rCBF increase after the 10 sessions of rTMS was found in the left prefrontal region (MANOVA F=5.29, d.f.=2,10, P=0.027), but no significant rCBF changes were found during the first rTMS session. The remaining cerebral regions showed no significant rCBF changes at any time. Only two patients showed a clinical improvement after rTMS, with 50% reduction of the initial HDRS score. The study was repeated under placebo conditions (identical design but addressing coil discharges to the air) in these two patients, who failed to show any rCBF increase during sham-rTMS. No relationship was found between the percentage of left prefrontal rCBF change and the clinical findings. In conclusion, rTMS of the left prefrontal cortex induces a significant rCBF increase in this region, despite the limited clinical effect in our sample of depressed patients. Cerebral perfusion SPECT is a useful tool to map cerebral activity changes induced by rTMS.

Obsessivecompulsive disorder and traumatic brain injury: behavioral, cognitive, and neuroimaging findings

OBJECTIVE

The goal of this study was to evaluate behavior and cognition in a consecutive series of patients who developed obsessive-compulsive disorder (OCD) after suffering a traumatic brain injury (TBI).

BACKGROUND

Because OCD is a rare sequelae of TBI, the phenomenology of obsessions and compulsions, the comorbid psychiatric disorders, the performance on cognitive tests, and the neural correlates have not been well characterized.

METHODS

Ten adult patients who met DSM-IV diagnostic criteria for OCD after suffering either mild (6 cases), moderate (2 cases), or severe (2 cases) TBI were studied using structured psychiatric rating scales (i.e., Yale-Brown Obsessive Compulsive Scale), cognitive tests, and magnetic resonance imaging (MRI).

RESULTS

Global severity of OCD ranged from moderate to severe, and all patients had multiple obsessions and compulsions. There was a high frequency of aggressive, contamination, need for symmetry/exactness, somatic, and sexual obsessions as well as cleaning/washing, checking, and repeating compulsions. Unusual features such as obsessional slowness (3 cases) and compulsive exercising (3 cases) were also documented. Comorbid psychiatric diagnoses were common and included posttraumatic stress disorder, anxiety with panic attacks, depression, and intermittent explosive disorder. Compared with 10 age-matched normal controls, the OCD group had poor performance on tests of general intelligence, attention, learning, memory, word-retrieval, and executive functions; these cognitive deficits were more pervasive among patients displaying obsessional slowness. All OCD patients with mild TBI had normal MRI scans, whereas focal contusions in the frontotemporal cortices, subcortical structures (caudate nucleus), or both were found in OCD patients with moderate and severe TBI.

CONCLUSIONS

Posttraumatic OCD has a relatively specific pattern of symptoms even in patients with mild TBI and is associated with a variety of other psychiatric disorders, particularly non-OCD anxiety. The patterns of cognitive deficits and MRI findings suggest dysfunction of frontal-subcortical circuits.

Reactivation of posttraumatic stress disorder after minor head injury

This report describes the reactivation of a posttraumatic stress disorder (PTSD) after a minor head injury in two young women who had recovered from extreme stress caused by sexual abuse during adolescence. Intrusive thoughts, images, dreams, and phobic avoidance bear a direct relationship to the specific circumstances of both head injury and sexual abuse, and were associated with obsessive-compulsive symptoms, generalized anxiety with panic, and depression. These findings suggest that in some individuals minor head injuries may induce not only extreme stress reactions, but also cause the reactivation of symptoms related to previous traumatic experiences.

Abnormalities of the acoustic startle reflex and reaction time in gilles de la tourette syndrome

OBJECTIVE

To study the startle reflex and the effect of the startle reflex stimulus over reaction time (start-react effect) in Gilles de la Tourette syndrome (GTS).

METHOD

Ten GTS patients and ten matched healthy volunteers underwent a simple RT paradigm (4 blocks of 50 trials). Forty acoustic startle reflex stimuli (110 dB) were randomly delivered with a 20% occurrence probability and presented unexpectedly at the same time as the imperative stimuli of the RT. Variables of interest were: amplitude, onset latency, degree of spread and rate of habituation of the startle response, and RT and the start-react effect caused by the startle stimuli.

RESULTS

GTS patients showed a significantly higher amplitude, a major degree of spread and fewer habituation phenomena of the startle reflex. GTS patients showed poorer non statistically significant RT performance compared to controls, with a significant correlation between RT and severity of the disease. The start-react effect was significantly less pronounced in GTS patients.

CONCLUSIONS

The present study confirms that GTS has an exaggerated startle reflex response and extend the spectrum of abnormalities to the start-react effect. A state of dopaminergic hyperactivity may have contributed to these results.

Chronic effects of dopaminergic replacement on cognitive function in Parkinson's disease: a two-year follow-up study of previously untreated patients

BACKGROUND

The cognitive effects of dopaminergic treatment in Parkinson's disease (PD) are still controversial.

OBJECTIVE

To evaluate, in previously untreated patients with PD, whether chronic dopaminergic stimulation produces significant cognitive changes; whether they are sustained beyond the period of a few months; and whether the cognitive status of two motor-comparable groups is differently affected by levodopa and pergolide.

DESIGN AND SUBJECTS

Parallel, randomized open study with blind neuropsychologic evaluation of 20 consecutive de novo patients with PD before and 3, 6, 12, 18, and 24 months after monotherapy with levodopa (n = 10) or pergolide (n = 10; 6-month monotherapy; pergolide + levodopa thereafter).

RESULTS

Both treatments were associated with a significant improvement in motor scores and in tests assessing learning and long-term verbal and visual memory, visuospatial abilities, and various frontal tasks. While improvement in motor scores persisted, improvement in activities of daily living and in semantic fluency, Luria's rhythm and motor and long-term memory tests was not sustained at the 24-month examination. Further, performance on attentional, short-term memory, and the Stroop tests did not change over the course of the study.

CONCLUSIONS

Both treatments were associated with incomplete but long-lasting (18 mos) improvement in many cognitive tasks which declined thereafter, suggesting that dopaminergic replacement is not enough to compensate for all cognitive deficits of PD.

Effects of alprazolam on the acoustic startle response in humans

In the present study, we assessed the effects of the potent benzodiazepine alprazolam on the human acoustic startle response in healthy volunteers. Eight undergraduate students received single oral doses of placebo and alprazolam 2 mg on 2 separate days, according to a double-blind balanced crossover design. Electromyographic activity of the orbicularis oculi muscle was recorded 5, 7 and 11 h after drug administration. At each recording time, subjects received 21 acoustic stimuli (1 KHz, 116 dB, 50 ms duration) separated by variable intervals (8-30 s, mean 16.5 s). Consistent with previous results obtained for diazepam in humans, alprazolam significantly reduced the amplitude of the startle reflex. A patent increase in onset latency was also observed, this being a novel effect not previously described for benzodiazepines in human studies. Both effects were maximum at 5 h after dosing, the startle response experiencing a recovery as the drug disappeared from systemic circulation. These results indicate a potent inhibitory effect of alprazolam on baseline startle at the dose used, with a robust time-dependent recovery of initial values effectively counteracting between-session habituation.

A randomized placebo-controlled comparative trial of gabapentin and propranolol in essential tremor

BACKGROUND

New medication is needed to treat essential tremor. Preliminary evidence suggests that gabapentin may be effective in the treatment of this disorder.

OBJECTIVE

To study the effects of gabapentin in a comparative, double-blind, crossover, placebo-controlled trial of patients who have essential tremor.

PATIENTS AND METHODS

16 patients with essential tremor (6 with a new onset and 10 with a 2-week washout period of previous treatment with propranolol hydrochloride) received gabapentin (Neurontin), 400 mg 3 times daily; propranolol hydrochloride, 40 mg 3 times daily; and placebo for 15 days with a 1-week washout period between treatments.

MAJOR OUTCOME MEASURES

Major outcome evaluations consisted of a Tremor Clinical Rating Scale, accelerometric recordings, and a self-reported disability scale obtained before drug intake on study days 1 and 15 of each treatment period. In addition, the initial (day 1) and superimposed (day 15) drug effects were studied before and 2, 4, 6, and 8 hours after drug intake.

RESULTS

At day 15, both gabapentin and propranolol demonstrated significant and comparable efficacy in reducing tremor from baseline in all tremor measures. The initial drug effects evaluated through accelerometry revealed no significant changes with the use of a placebo, but gabapentin and propranolol use significantly reduced tremor power.

CONCLUSION

Gabapentin may be useful for the treatment of essential tremor.

A six-month study of pergolide and levodopa in de novo Parkinson's disease patients

Formal studies examining the antiparkinsonian efficacy of levodopa and pergolide monotherapy in de novo Parkinson's disease (PD) are lacking. The authors conducted a preliminary, 6-month, open-label parallel experimental study with de novo consecutive PD patients who were randomly assigned to three daily doses of pergolide (n = 10; mean age, 63.7 years; mean Hohen & Yahr score, 1.5; mean final dose, 2.8 mg daily) or levodopa (n = 10; mean age, 67.3 years; mean Hohen & Yahr score, 1.8; mean final dose, 435 mg daily). Doses were titrated individually according to patients' evaluation of their own functional ability, known side-effects, and a monthly administration of the Unified Parkinson's Disease Rating Scale (UPDRS) by a clinician blind to the treatment regime. All patients completed the study. There were no significant basal differences between groups and no significant treatment ortreatment-by-time effects in UPDRS scores (according to two-way ANOVA). A clear time effect was observed for most of the functional and motor variables (p < 0.001), with significant improvement during the first month that was maintained for the duration of the study in both groups. Side effects were mild, transient, and comparable. In this preliminary study, pergolide and levodopa exhibited similar symptomatic efficacy and incidence of side effects in the short-term treatment of de novo PD patients at their usual age of clinical manifestation.

Unrecognized Tourette syndrome in adult patients referred for psychogenic tremor

BACKGROUND

The diagnosis of Tourette syndrome may be overlooked in patients with severe psychopathologic disorder but mild motor manifestations of Tourette syndrome.

OBJECTIVE

To describe 4 patients with long-lasting general psychopathologic disorder and previously unrecognized mild motor and phonic tics exacerbated during adulthood by the onset of tremor; all of the patients had been referred for the evaluation of psychogenic tremor.

SUBJECTS

Four adult patients, with previous psychiatric diagnoses of depression (2 cases), generalized anxiety disorder (3 cases), malingering (1 case), and conversion disorder (3 cases).

METHODS

Single case studies.

RESULTS

Clinical interviews disclosed that the 4 patients had positive family histories of Tourette syndrome, and all had mild motor and phonic tics that had started before the age of 18 years. On neurologic examination, 2 patients had bilateral postural tremor of the hands that varied in frequency, rhythmicity, and amplitude, and the other 2 had resting tremor mimicking parkinsonism. All 4 patients described involuntary somatic sensations of the affected limbs, which they attempted to alleviate by executing movements. No consistent positive placebo response was observed, but in all patients tremoric movements improved with haloperidol.

CONCLUSIONS

These cases illustrate an unusual movement disorder (tremor as a "tic equivalent") in adults with Tourette syndrome and emphasize that cases of the syndrome with mild tics often go unrecognized, precluding adequate treatment.

[Psychogenic tremor: clinical, electrophysiologic and psychopathologic assessment]

There are few studies analyzing the incidence, clinical characteristics and diagnostic work-up of psychogenic tremor. We studied the clinical and electrophysiological characteristics and the associated psychopathology in a series of patients with psychogenic tremor. All patients (n = 8) diagnosed with documented or clinically established psychogenic tremor in the movement disorders section of our Department of Neurology in a two-years period were analysed. Psychogenic tremor was diagnosed in 9.5% of the patients that consulted for postural or action tremor of the upper limbs. In all cases tremor had a variable frequency and amplitude and improvement with distraction. Electrophysiological studies revealed asynchronic muscle activity and considerable variation of the dominant frequency when weight was added to the patient hands. Six patients were initially misdiagnosed of essential tremor (n = 3); Parkinson's disease (n = 1); and cerebrovascular disease (n = 2). Final psychiatric diagnoses were depression (n = 4); conversive disorder (n = 2); and malignering (n = 2). Psychogenic tremor is a relatively frequent cause of tremor in a Movement Disorders Clinic and has a characteristic clinical and electrophysiological pattern.

Acute effects of levodopa on neuropsychological performance in stable and fluctuating Parkinson's disease patients at different levodopa plasma levels

The contribution of dopaminergic systems to cognitive defects in Parkinson's disease and the cognitive effects of levodopa remain controversial. The levodopa plasma levels and the neuropsychological performance of 10 parkinsonian patients with a stable motor response to the drug and 10 matched parkinsonian patients with a 'wearing-off' phenomenon were studied 12 h after levodopa was withdrawn (time zero), and at 1 h and 4 h after an oral dose of levodopa (i.e. at '+1H' and '+4H'), to investigate whether discrete cognitive domains are more sensitive to levodopa in parkinsonian patients with the wearing-off phenomenon. Considering the 20 patients as a whole, levodopa significantly diminished the response time in verbal and visuospatial memory tests, the extradimensional matching test and the Wisconsin card sorting test (WCST), without significantly improving or worsening the patient's accuracy. A significant group-by-time effect was only evident in the WCST; while in stable patients levodopa produced no changes, wearing-off patients significantly reduced the number of categories achieved and had more perseverative errors at +1H, recovering at +4H. These results confirm previous findings of selective adverse effects of levodopa on highly demanding executive tasks in Parkinson's disease and additionally suggest that some previous discrepancies between studies may be accounted for by lack of differentiation between stable and wearing-off conditions. 'Frontal' disturbances on neuropsychological tests with levodopa may become evident only after massive degeneration of the dopamine systems has occurred.

Isolated dysarthria caused by a right paravermal infarction

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Obsessive-compulsive disorder associated with brain lesions: clinical phenomenology, cognitive function, and anatomic correlates

We studied the behavioral, cognitive, and neuroimaging characteristics of obsessive-compulsive disorder (OCD) in 13 patients with focal brain lesions (acquired OCD) and compared their clinical features and the severity of obsessive and compulsive (OC) symptoms with patients with idiopathic OCD. Both OCD groups were further compared with matched normal controls on a series of neuropsychological tests. Patients with acquired OCD had a negative familial history and later age at onset of OCD symptoms than patients with idiopathic OCD. The two OCD groups showed relatively similar clinical phenomenology, severity of OC symptoms, and profile of neuropsychological deficits. Compared with normal control subjects, both OCD groups showed cognitive deficits affecting attention, intellectual function, memory, word retrieval, and motor and executive functions. Eight of the 13 patients with acquired OCD had abnormal neurologic examinations, whereas only 3 of the 13 patients with idiopathic OCD had abnormal neurologic examinations. Neuroimaging in the acquired OCD group disclosed a variety of lesions involving exclusively the cerebral cortex (frontal, temporal, or cingulate regions), the basal ganglia, or both. These results suggest that acquired and idiopathic OCDs may share a common pathophysiologic mechanism, and that structural damage to specific frontal-limbic-subcortical circuits plays an important role in the pathogenesis of acquired OCD.

Pentosan polysulfate-induced thrombocytopenia: a case diagnosed with an ELISA test used for heparin-induced thrombocytopenia

We report a patient who developed severe thrombocytopenia and ischemic stroke following pentosan polysulfate treatment. An ELISA test employed in type-II heparin-induced thrombocytopenia was highly positive. To our knowledge, this is the first case in which this test has been performed in a pentosan polysulfate-induced thrombocytopenia (PIT). Our data suggest that the antibody against pentosan polysulfate-platelet complex also cross-reacts with heparin-platelet factor 4 complex. Due to its greater sensitivity and wider availability, this ELISA test should be used in cases where PIT is suspected.

[A retrospective study of potential benefits of thrombolytic drugs in a stroke]

We carried out a retrospective analysis into the possible uses of thrombotic drugs on 190 consecutive patients with ischaemic stroke who had been admitted to the Neurological Service of the Barcelona 'Hospital de la Santa Creu i Sant Pau' in accordance with exclusion criteria commonly accepted for the use of this type of medication. We thus analyzed the initial symptoms, type of instauration, etiological diagnosis and topographical diagnosis. In those patients who could be possible candidates for such treatment with these drugs we assessed their disability variations (on the Rankin scale) at the end of two weeks using currently available therapeutic means. 70% of patients would subsequently be excluded from our study. Among reasons for exclusion were especially minor neurological deficiencies, age and latency time. As for patients included, most predominant factors were immediate instauration, cardioembolic etiological mechanism and severe onset symptomatology (motor disorder, awareness and language abnormalities). We observed a substantial spontaneous improvement in 7% of patients. This fact is especially clear in cardioemboligenic etiology patients. Bearing the spontaneous improvement cases in mind, we concluded that some 23% of patients with ischaemic cerebrovascular pathology could benefit from thrombotic drugs in our milieu.

Poststroke bipolar affective disorder: clinical subtypes, concurrent movement disorders, and anatomical correlates

The authors describe 9 patients with bipolar affective disorder associated with cerebrovascular lesions. Eight had negative family histories of affective disorders and late age at onset (after age 40) of manic-depressive symptoms. Only one, with positive family history of affective disorders, developed mood swings before age 40. Clinical subtypes of bipolar disorder and patterns of affective cycling in these stroke patients resembled those previously reported in functional bipolar disorder. Five patients had concurrent hyperkinetic movement disorders, and one depressed patient presented with unilateral left-sided parkinsonism that disappeared during a manic switch. In most patients, bipolar affective disorder was associated with right hemisphere lesions that involved subcortical and midline structures. Findings suggest that damage to frontal-basal ganglia-thalamocortical circuits by subcortical vascular lesions may simultaneously provoke disorders of movement and mood regulation.

Hemorrhagic stroke as a complication of bacterial meningitis in adults: report of three cases and review

We describe three adults who had hemorrhagic strokes during the acute phase of bacterial meningitis (BM). We also report the results of a literature review and a review of the charts of 296 adults treated at our hospital for acute BM. The diagnosis of hemorrhagic stroke was made based on the results of cerebral computed tomography (CT) for two of 92 patients with BM who had CT performed and by means of lumbar puncture and a postmortem study in one other case. Two patients died of cerebral bleeding. Although the frequency of hemorrhagic stroke was only 2.1% among adults with acute BM, it is a major determinant of prognosis for such patients.

Absence of REM sleep and altered non-REM sleep caused by a haematoma in the pontine tegmentum

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