Evaluation of cerebral vasomotor reactivity in Parkinson's disease: is there any association with orthostatic hypotension?

Objective

Our aim was to look for a probable relationship between cerebral vasomotor reactivity (VMR) and orthostatic hypotension (OH) in Parkinson's disease (PD).

Materials and methods

This study was conducted on 44 patients with PD. Assessment of cerebral VMR was performed by means of transcranial Doppler (TCD) of middle cerebral artery (MCA) before and after a vasodilatory stimulus, carbon dioxide test. Moreover, orthostatic hypotension was evaluated.

Results

OH was presented in 12 (27.3%) Parkinson's patients. The average resting blood flow velocity (BFV) in the MCA was 30.20 (SD = 9.58) cm s⁻¹ which significantly increased to 46.25 (SD = 16.23) cm s⁻¹ after carbon dioxide test (P < 0.001). Impaired VMR was observed in 15 (34.1%) of the subjects, while it was not associated with the presence of OH (P = 0.770).

Conclusion

Evaluation of VMR in patients affected by PD, could assist in early diagnosis of cerebral autonomic dysfunction and prevent its serious consequences prior and more valid to OH.     

Strategy instruction in Parkinson's disease: Influence on cognitive performance

Objectives

Though strategic deficits are extensively investigated in Parkinson's disease (PD), little is known about the effects of instruction for PD patients. Thus, we compared the ability to internally generate a cognitive strategy with the ability to use a strategy after elaborate strategy instruction.

Methods

Patients with PD (n = 14) and matched healthy controls (n = 22) were administered a Numerosity Judgement task in which they had to determine different numerosities of blocks presented in a square grid. In more complex task configurations, healthy participants tend to use a subtraction strategy. Participants in our study were confronted with a counting condition (A), a strategy initiation condition without instruction (B), and a strategy elaboration and strategy training condition (C).

Results

Patients and controls were comparable with respect to basic cognitive measures. PD patients and controls performed equivalently within the counting condition (A), but patients needed significantly more trials to initiate the subtraction strategy. With the exception of 1 PD patient, all patients were able to internally initiate the strategy (condition B). In condition C, both groups increased reaction times, but patients were significantly slower than controls. Moreover, only patients significantly increased error rates after strategy instruction.

Conclusion

As long as sufficient time is provided for solving the task, results do not show a general deficit in the ability to internally generate a cognitive strategy in PD. Failures in strategy utilization strongly depend on cognitive load (working memory, executive functions). This bears important implications for the neuropsychological rehabilitation of PD patients.     

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

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.     

Short questionnaire for Parkinson's disease as a screening instrument

Objective

To validate and simplify a screening questionnaire for the determination of PD.

Methods

The screening questionnaire for PD was developed with the permission of the author. Reliability of the questionnaire was tested. To validate the questionnaire, 40 patients with PD and 93 controls completed the questionnaire. Multiple logistic regression analysis was used to determine the questions independently associated with PD and a risk score was calculated. The predictive performance of the risk score was evaluated via the area under the curve (AUC) of a receiver operating characteristics (ROC) curve.

Results

The questionnaire showed a Cronbach's alpha coefficient of 0.73 with no difference between the initial and follow up scores. The mean content validity was 0.86. Of the 11 questions, 4 were independently associated with PD and were used to calculate the risk score. The scores of these questions were 2 (clumsiness) + 4 (tremor) + 2 (masked face) + 2 (loss of balance while turning). The AUC of a ROC curve for the sum of risk score was 0.95. With a cutoff score of 5 or higher, the sensitivity and specificity were 0.88 and 0.95, respectively.

Conclusions

The screening questionnaire for PD is a reliable and valid instrument. The predictive performance of the simplified questionnaire is as good as the original.     

Clinical outcomes of PD patients having bilateral STN DBS using high-field interventional MR-imaging for lead placement

Objective

Recently, an iMRI-guided technique for implanting DBS electrodes without MER was developed at our center. Here we report the clinical outcomes of PD patients undergoing STN DBS surgery using this surgical approach.

Methods

Consecutive PD patients undergoing bilateral STN DBS using this method were prospectively studied. Severity of PD was determined using the UPDRS scores, Hoehn and Yahr staging score, stand-sit-walk testing, and the dyskinesia rating scale. The primary outcome measure was the change in UPDRS III off medication score at 6 months. DBS stimulation parameters, adverse events, levodopa equivalent daily dose (LEDD), and DBS lead locations were also recorded. Seventeen advanced PD patients (9M/8F) were enrolled from 2007 to 2009.

Results

The mean UPDRS III off medication score improved from 44.5 to 22.5 (49.4%) at 6 months (p = 0.001). Other secondary outcome measures (UPDRS II, III on medication, and IV) significantly improved as well (p < 0.01). LEDD decreased by an average of 24.7% (p = 0.003). Average stimulation parameters were: 2.9 V, 66.4 μs, 154 Hz.

Conclusion

This pilot study demonstrates that STN DBS leads placed using the iMRI-guided method results in significantly improved outcomes in PD symptoms, and these outcomes are similar to what has been reported using traditional frame-based, MER-guided stereotactic methods.     

Prevalence and determinants of depression in Mexican patients with Parkinson's disease

Objective

To assess the prevalence and associated factors of depression in a Mexican Parkinson's disease (PD) population.

Background

Depressive symptoms are frequent in PD and have been recognized as a major determinant of quality of life. Only two previous studies have partially addressed depression in Mexican PD patients.

Methods

One hundred forty-seven non-demented PD patients were recruited at the movement disorder specialist clinic at the National Institute of Neurology and Neurosurgery, Mexico City. The following sociodemographic variables were collected: gender, age, age at onset, disease duration and disease severity in terms of Hoehn and Yahr stage. PDQ-8, NMSQuest and Beck Depression Inventory (BDI) were applied to all participants.

Results

One hundred forty-seven patients were included (49.7% female). The mean age of the sample was 62.1 ± 11.7 years, the mean age at diagnosis was 55.8 ± 12.3 and the mean duration of the disease was 6.3 ± 5 years. A total of 49 (33.3%) patients were diagnosed with current depression. Depressed patients also scored higher in the NMSQuest even when depression/anxiety items were excluded. Differences were found in gender, UPDRS III score and HY stage, but after the logistic regression analysis was performed only the NMSQuest score and low education remained as statistically significant factors for depression in Mexican PD patients.

Conclusions

Depression prevalence in PD Mexican patients is similar to other international reports. The main associated factor was the presence of non-motor symptoms.     

A validation study of the Chinese wearing off questionnaire 9-symptom for Parkinson's disease

Objective

Development of wearing off (WO) often goes unnoticed for both patients with Parkinson's disease (PD) and physicians due to the complexity of this phenomenon. A brief 9-symptom WO questionnaire (WOQ-9) was recently found to be highly sensitive in its detection. We aimed to validate a Chinese version WOQ-9 (CWOQ-9) among Chinese patients with PD.

Methods

We recruited 101 literate Chinese PD patients among 4 different neurology or movement disorders clinics in Hong Kong to participate in this study by completing the CWOQ-9. Clinical judgment by the specialists was considered the gold standard for diagnosing WO.

Results

The mean age (±SD) of the patients was 61 (±9) years and 35 (34.7%) of them were female. The disease duration was 7.4 (±5.4) years and 69 (68.3%) of them were diagnosed clinically to have WO by the specialists. The positive and negative predictive values, sensitivity and specificity of CWOQ-9 were 86%, 71%, 87%, and 69% respectively. The area under curve (AUC) was 0.78 (p < 0.001).

Conclusion

This simple patient questionnaire is a valid tool for the detection of WO among Chinese PD patients.     

Aggression and psychopharmacological treatments in major psychosis and personality disorders during hospitalisation

Background

A number of large-scale studies have shown that there is a relationship between many psychiatric disorders and aggression or violence. As no medication is currently approved for the treatment of aggression, pharmacotherapy (often involving drug combinations) is used on a trial-and-error basis with various degrees of response.

Method

The study involved 244 in-patients aged 19-83 years (mean 41.9 ± 11.3 SD). The Modified Overt Aggression Scale (MOAS) was used to assess any aggressive or violent behaviors occurring in the week before admission and upon discharge.Psychopathology was assessed using the Brief Psychiatric Rating Scales (BPRS).

Results

All of the patients showed a significant improvement (p < 0.001) in mean weighted total MOAS scores at the end of the study, with no significant differences between the various drugs or combination therapies. The patients who received combination treatments including antidepressants showed a worsening in the weighted total MOAS score (18.46% ± 114.31% SD); the patients who did not receive antidepressants had an improvement (13.61% ± 257.36% SD) (p = 0.0069).

Conclusions

Multivariate testing of the variables age, gender, substance/alcohol abuse, the duration of hospitalisation, the administration of mood stabilisers, and the use of typical or atipical antipsychotics showed that the severity of the psychopathological picture correlated significantly with the presence of violence, whereas the effect of combined antidepressant treatment on violent behavior was only relative.     

Behavioral, neuropsychiatric and cognitive disorders in Parkinson's disease patients with and without motor complications

Background

Parkinson's disease (PD), commonly defined as a hypokinetic movement disorder, is hampered by the appearance of motor complications (MC), including dyskinesias and motor fluctuations, and non-motor symptoms such as behavioral, neuropsychiatric and cognitive disorders, which, in the last years, are gaining increasing attention. The factors affecting MC and these non-motor symptoms are still largely unknown and their interactions are not yet fully evaluated.

Objective

To identify the presence of behavioral, neuropsychiatric and cognitive disorders in PD patients with and without MC and to evaluate their association with MC.

Methods

Consecutive PD patients received a comprehensive structured clinical evaluation including pharmacologic treatment, MC and non-motor symptoms such as reward-seeking behaviors, neuropsychiatric symptoms (depression, anxiety, psychoses and hallucinations) and dementia.

Results

349 patients were included in this analysis. Patient with MC showed enhanced frequency of dementia (p < 0.001), anxiety, depression and psychoses (p < 0.01). A higher frequency of impulse control disorders was detected in patients with dyskinesias (22.2% — p < 0.001) and motor complications (12.2% — p < 0.05). Dyskinesias were significantly more present in patients with hypersexuality (p < 0.05) and compulsive shopping (p < 0.001), while they were not significantly associated with pathological gambling and binge eating. Patients with dyskinesias also had significantly higher frequency of dopamine dysregulation syndrome, hallucinations and delusions (p < 0.001), with the exception of delusional jealousy.

Discussion

We found a higher frequency of behavioral, neuropsychiatric and cognitive disorders in patients with MC. The lack of detection of dyskinesias in several PD patients with pathological gambling in our study represents a very interesting issue. While binge eating mainly seems to be related to the use of dopamine agonists, the significant lack of association between dyskinesias and delusional jealousy suggests the hypothesis of a possible underlying psychopathological predisposition rather than a mere pharmacologic effect in PD patients with these behavioral complications.     

Influence of blood viscosity to cerebral blood flow in older humans compared to young subjects

Objective

Since blood viscosity (BV) is one of the most important factors determining blood flow, this study aimed to investigate the possible correlation between increased blood viscosity and reduction of regional cerebral blood flow (rCBF) in healthy ageing.

Methods

Male subjects were distributed in two groups: “young”, aged 20-30 (27 volunteers), or “elderly”, aged 60-70 (50 volunteers). Whole blood viscosity was obtained with a Wells-Brookfield Cone/Plate Viscometer. Cerebral blood flow was analysed by means of single photon emission computed tomography (SPECT).

Results

The mean BV values were 3.28 ± 0.43 mPa in the group of young volunteers and 4.33 ± 0.73 mPa in the group of elderly volunteers (t = −6.9, p < 0.0001). The elderly had a lower blood flow than the young in the following regions: bilateral parietal; temporal-parietal and temporal of the left hemisphere. Pearson’s correlation between BV and rCBF showed a good inverse correlation when the BV was above 3.95 ± 0.83 mPa.

Conclusions

Our results point to a close relationship between the two parameters analysed, BV and rCBF. The impairment in rCBF observed in the elderly volunteers might be due to an increase in BV, among other factors.

Significance

These findings suggest interesting possibilities for the treatment/prevention of brain ageing.     

Association study of PDE4B with panic disorder in the Japanese population

Background

Panic disorder (PD) is a severe and chronic psychiatric disorder with genetic components underlying in its etiology. The Phosphodiesterase 4B (PDE4B) gene has been reported to be associated with several psychiatric disorders. Several studies indicated that PDE4B may be involved in the regulation of anxiety and depression. Therefore, we investigate the association of PDE4B with PD in the Japanese population.

Methods

We genotyped 14 single nucleotide polymorphisms (SNPs) of PDE4B in 231 PD cases (85 males and 146 females) and 407 controls (162 males and 245 females). Differences in the genotype, allele and haplotype frequencies between the two groups were compared.

Results

We found a significant association between PDE4B and PD in the haplotype analysis (haplotype C-T-T-A, permutation P = 0.031, OR = 1.81, 95% CI = 1.30-2.51). Sex-specific analyses demonstrated that PDE4B was associated with PD in females in the allele/genotype and haplotype analyses (rs10454453, allele P = 0.042, genotype P = 0.0034; haplotype C-T-T-A, permutation P = 0.028).

Conclusion

Our results suggest that PDE4B may play a role in the pathophysiology of PD in the Japanese population. Replication studies using larger samples will be needed for more reliable conclusions.     

Hypercoagulability in chronic kidney disease is associated with coagulation activation but not endothelial function

Introduction

Patients with chronic kidney disease exhibit features of a hypercoagulable state and have endothelial dysfunction, which may contribute to their increased cardiovascular risk. We examined the relationship between coagulation activation and vascular function in patients with chronic kidney disease.

Materials and Methods

We measured parameters of the tissue factor pathway of blood coagulation (tissue factor, factor VIIc and factor X); natural inhibitors (tissue factor pathway inhibitor, protein C, free and total protein S, antithrombin III) and markers of coagulation activation (thrombin-antithrombin complexes, prothrombin fragment 1 + 2) in 66 stage 4&5 chronic kidney disease patients and 36 healthy controls. Their relationship with markers of vascular function (flow mediated dilatation, soluble E-selectin and thrombomodulin) and a mediator of inflammation (interleukin-6) was determined.

Results

Up-regulation of the tissue factor pathway (increased tissue factor and factor VIIc), increased prothrombin fragment 1 + 2 and significant reductions in antithrombin III and the ratio of free protein S: total protein S were found in patients compared to healthy controls. Increased tissue factor antigen was significantly and independently correlated with creatinine and interleukin-6 (P < 0.001). Factor X and antithrombin III were both reduced in chronic kidney disease and correlated (r = 0.58; P < 0.001). Changes in coagulation and anti-coagulation were independent of all measures of endothelial function.

Conclusions

Significant activation of the TF pathway of coagulation and depletion or reduction of some natural anticoagulants in chronic kidney disease was correlated with the degree of renal dysfunction, but not correlated with the abnormalities of vascular function. These data are consistent with a hypercoagulable state in chronic kidney disease that may be independent of endothelial based regulation but associated with an inflammatory state.     

RBD in Parkinson's disease: a clinical case control study from North India

Objectives

Sleep related complaints and rapid eye movement (REM) behavior disorder (RBD) are commonly reported in patients with Parkinson's disease (PD). The study aimed to compare the characteristics of patients with PD with RBD versus those without RBD.

Methods

Consecutive patients with PD were evaluated with detailed clinical history, examination and questionnaire on sleep RBD over a two year period. Clinical scores included Unified Parkinson's Disease Rating Scale (UPDRS), Hoehn & Yahr Stage (H & Y), Schwab and England (S & E) scale, Mini Mental Status Examination (MMSE), EuroQol, Parkinson's disease Sleep Scale (PDSS) and Epworth Sleep Scale (ESS). The qualitative data was analyzed using chi square/Fischer's exact test and continuous variables were analyzed using Student's t-test.

Results

The study included a total of 134 patients. RBD was present in 26 (19.4%) patients. There was increased occurrence of hallucinations in patients with RBD. None of the patients had familial PD. Patients with RBD had significantly higher prevalence of insomnia, nocturnal awakening, early morning awakenings and snoring. Most clinical events were brief and confined to vocalization or limb movements.

Conclusion

RBD may precede or follow PD onset. RBD has association with higher occurrence of hallucinations and other nocturnal problems; although most of these episodes were brief, had static course and were not associated with violent behavior.     

Acetyl-l-Carnitine in the treatment of anhedonia, melancholic and negative symptoms in alcohol dependent subjects

Objective

Aim of this randomized, double-blind, placebo-controlled study was to evaluate the efficacy of Acetyl-l-Carnitine (ALC), at different dosages, on specific anhedonic symptoms in detoxified alcohol dependent subjects. Secondary endpoints were the effect of ALC on melancholic and negative symptoms.

Method

Sixty-four anhedonic alcohol dependent patients with minor or absent withdrawal symptoms were randomized: 23 received ALC at a dosage of 3 g/day, 21 received ALC at a dosage of 1 g/day, and 20 were given placebo. ALC was given intravenously for 10 days, followed by 80 days of oral treatment plus a follow-up period of 45 days. The presence of anhedonic symptoms was determined by the SHAPS (Snaith-Hamilton Pleasure Scale) and the VASa (Visual Analogue Scale for Anhedonia); negative and melancholic symptoms were evaluated by the SANS (Scale for the Assessment of Negative Symptoms), and the BRMS (Bech-Rafaelsen Melancholia Scale).

Results

The natural course of anhedonia in the placebo group showed a decline until day 30 and remains stable for the rest of the study. Intravenously ALC accelerated the improvement of anhedonia reaching constant low levels early, on day 10. At this step levels of anhedonia (SHAPS, VASa) and melancholic symptoms (BRMES) resulted significantly reduced (p < 0.05) in both the ALC 3 g and ALC 1 g groups with respect to placebo; SANS scores significantly reduced only in the ALC 1 g respect to placebo (p = 0.014). During oral treatment with ALC, anhedonia scores did not differ from placebo.

Conclusion

Intravenously ALC was effective in accelerating the abstinence-associated improvement of anhedonia, melancholic and negative symptoms, whereas oral ALC treatment starting on day 10 showed no further improvements. Accordingly, in alcohol dependent subjects, ALC may be considered as a new potentially useful drug for the treatment of anhedonia.     

Rapid decrease in depressive symptoms with an N-methyl-d-aspartate antagonist in ECT-resistant major depression

Background

Ketamine rapidly improves depressive symptoms in patients with treatment-resistant major depressive disorder (MDD) who do not respond to multiple standard antidepressants. However, it remains unknown whether ketamine is equally effective in patients with MDD who previously also did not respond to electroconvulsive therapy (ECT).

Methods

This study compared 17 patients with treatment-resistant MDD who previously did not respond to ECT and 23 patients with treatment-resistant MDD who had not previously received ECT. All subjects received a single open-label infusion of ketamine (0.5 mg/kg). Patients were evaluated using the Montgomery-Asberg Depression Rating Scale (MADRS) at baseline (60 min before the infusion), as well as at 40, 80, 120, and 230 min after infusion.

Results

Depressive symptoms were significantly improved in the ECT-resistant group at 230 minutes with a moderate effect size (p < .001, d = 0.50, 95% C.I.: 0.21-0.80). At 230 minutes, the non-ECT exposed group showed significant improvement with a large effect size (p < .001, d = 1.00, 95% C.I.: 0.71-1.29).

Conclusion

Ketamine appears to improve depressive symptoms in patients with MDD who had previously not responded to ECT. These preliminary results encourage further investigation with a larger sample size to determine effectiveness compared to other treatment-resistant patients with MDD.     

Serotonin transporter binding as a possible predictor of one-year remission in major depressive disorder

Objective

Lower serotonin transporter (5-HTT) binding (BP_P = f_PB_avail/K_D) is reported during a major depressive episode (MDE) compared to healthy controls. Higher 5-HTT binding in the diencephalon has previously been associated with acute response to antidepressant treatment. We assessed baseline 5-HTT binding as a predictor of one-year remission from a MDE, examining binding in brain regions implicated in the pathophysiology of major depressive disorder (MDD).

Methods

5-HTT binding was quantified using positron emission tomography (PET) with [¹¹C]McN5652 in 19 currently depressed subjects with MDD and 41 healthy controls. Depressed subjects received open, naturalistic antidepressant treatment. Remission status was determined one year after PET scan and treatment initiation.

Results

Significant differences in 5-HTT binding among the three groups (healthy controls, remitters, and non-remitters) were observed in a linear mixed-effects model. Post hoc, non-remitters had lower 5-HTT binding than controls in midbrain, amygdala, and anterior cingulate. Remitters did not differ significantly from controls or non-remitters in 5-HTT binding. Remitters did not differ from non-remitters in clinical characteristics apart from greater family history of depression among non-remitters. A logistic regression model fit to determine the capacity of baseline 5-HTT binding to predict remission status at one year yielded a coefficient that was suggestive but not significant (p = 0.057).

Limitations

The small sample size and heterogeneous treatments received reduced statistical power to detect differences in binding based on clinical outcome.

Conclusions

Lower pretreatment 5-HTT binding may be predictive of non-remission from major depression following one year of naturalistic antidepressant treatment. Future studies using standardized treatment are warranted.     

Diurnal variation of soluble CD40 ligand in patients with acute coronary syndrome. Soluble CD40 ligand and diurnal variation

Introduction

We sought to investigate whether day-night variations occur in the concentration of circulating soluble CD40 ligand in patients with acute coronary syndrome, as this may have practical implications.

Materials and Methods

We assessed 70 consecutive ST-segment elevation myocardial infarction patients admitted into the Coronary Care Unit and 50 control subjects. Each subject was studied under strictly controlled light/dark conditions. Blood samples were drawn at 09:00 h (light phase) and 02:00 h (dark phase). Nocturnal blood samples were drawn by a trained nurse, with the help of a minute torch with a dim red light in order to avoid any direct lighting on the patient during sleep. The soluble CD40 ligand was measured using a commercially available ELISA.

Results

Soluble CD40 ligand levels showed no diurnal variations in control subjects. In the ST-segment elevation myocardial infarction group, however, soluble CD40 ligand concentration (pg/mL) in the light phase was significantly higher than that in the dark phase (167.3 ± 63.2 vs 118.9 ± 48.3 pg/mL, p < 0.001).

Conclusions

The study shows for the first time the existence of diurnal variations in soluble CD40 ligand levels in ST-segment elevation myocardial infarction patients, which indicates the need for standardizing the time of blood sampling for the assessment of this molecule, at least in studies involving ST-segment elevation myocardial infarction patients.     

Sunshine-exposure variation of human striatal dopamine D2/D3 receptor availability in healthy volunteers

Background

In addition to the serotonergic system, the central dopaminergic system has been reported to be correlated with seasonality. The aim of this study was to explore the difference in striatal dopamine D₂/D₃ receptor availability between healthy volunteers who had a high-sunshine exposure and those who had a low exposure.

Methods

Sixty-eight participants were enrolled, and those in the upper and lower quartiles in terms of sunshine exposure were categorized into high- (n = 17) and low-sunshine-exposure (n = 18) subgroups. Single photon emission computed tomography with [¹²³I] iodo-benzamide was used to measure striatal dopamine D₂/D₃ receptor availability.

Results

Striatal dopamine D₂/D₃ receptor availability was significantly greater in the subjects with high-sunshine exposure than in those with low-sunshine exposure (F = 7.97, p = 0.01) after controlling for age, sex, and smoking status.

Limitations

Different subjects were examined at different time points in our study. In addition, the sex and tobacco use distributions differed between groups.

Conclusion

The central dopaminergic system may play a role in the neurobiological characteristics of sunshine-exposure variation.     

Retinal thickness in patients with mild cognitive impairment and Alzheimer's disease

Objectives

Mild cognitive impairment (MCI) may represent a transition to early Alzheimer's disease (AD). The retinal nerve fiber layer (RNFL) is composed of axons originating in retinal ganglion cells that eventually form the optic nerves. Previous studies have shown that degenerative changes occur in optic nerve fibers and manifested as thinning of RNFL in patients with AD. The objective of this study was to assess the relationship between MCI, AD and loss of RNFL.

Patients and methods

In this study, patients fulfilling diagnostic criteria for MCI (n = 24), AD (n = 30) and cognitively normal age-matched controls (n = 24) have undergone neuro-ophthalmologic and optical coherence tomography (OCT) examinations to measure RNFL thickness.

Results

There was a significant decrease in RNFL thickness in both study groups (AD and MCI) compared to the control group, particularly in the inferior quadrants of the optic nerve head, while the superior quadrants were significantly thinner only in AD. Although AD patients may have more severe changes than MCI cases, the differences were statistically nonsignificant. Furthermore among AD patients, there was no relation to the severity of the dementia.

Conclusions

Our data confirm the retinal involvement in AD, as reflected by loss of axons in the optic nerves.     

OCT assessment of morphological changes of the optic nerve head and macula in idiopathic intracranial hypertension

Objective

To assess the morphologic changes of the optic nerve head and macula in patients with idiopathic intracranial hypertension (IIH) with optical coherence tomography (OCT).

Methods

Data was extracted from the medical records and Stratus OCT images of IIH patients.

Results

Ninety-one eyes of 48 IIH patients were divided into 3 groups according to their clinical optic disc appearance. Average retinal nerve fiber layer (RNFL) thickness was statistically different between the groups: normal optic disc/mild elevation group (N = 20) - 89 μm (95% CI, 80-98 μm), mild elevation group (N = 51) - 109 μm (95% CI, 101-117 μm), and papilledema group (N = 20) 124 μm (95% CI, 100-153 μm) (P = 0.004). Fast macular thickness map did not demonstrate a significant difference between the groups for most measured macular areas (N = 49 eyes).

Conclusions

Peripapillary RNFL measurements correlated with the clinical appearance of the optic discs, suggesting that OCT may assist in the follow up of IIH patients.