Daniela Di Giuda

MIBG scintigraphy in differential diagnosis of Parkinsonism: a meta-analysis

ObjectiveDifferential diagnosis between Parkinson’s disease (PD) and other Parkinsonism using clinical criteria or imaging methods is often difficult. The purpose of this study is to systematically review and meta-analyze published data about the diagnostic performance of myocardial innervation imaging using 123I-metaiodobenzylguanidine (MIBG) scintigraphy in differential diagnosis between PD and other Parkinsonism.MethodsA comprehensive computer literature search of studies published through March 2011 regarding MIBG scintigraphy in patients with PD and other Parkinsonism was performed in PubMed/MEDLINE and Embase databases. Only studies in which MIBG scintigraphy was performed for differential diagnosis between PD and other Parkinsonism were selected. Pooled sensitivity, pooled specificity and area under the ROC curve were calculated to measure the accuracy of MIBG scintigraphy in differential diagnosis between PD and other Parkinsonism.ResultsNineteen studies comprising 1,972 patients (1,076 patients with PD, 117 patients with other Lewy body diseases and 779 patients with other diseases) were included in this meta-analysis. The pooled sensitivity of MIBG scintigraphy in detecting PD was 88% (95% CI 86–90%); the pooled specificity of MIBG scintigraphy in discriminating between PD and other Parkinsonism was 85% (95% CI 81–88%). The area under the ROC curve was 0.93.ConclusionsIn patients with clinically suspected PD, myocardial innervation imaging demonstrated high sensitivity and specificity. MIBG scintigraphy is an accurate test in this setting. Nevertheless, possible causes of false-negative and false-positive results should be kept in mind when interpreting the scintigraphic results.

Dopamine transporter binding in depressed patients with anhedonia

Central dopaminergic dysfunction has been widely proposed as a common neurobiological correlate of the psychopathological expression of anhedonia. The dopamine transporter (DAT) is a predominantly presynaptic receptor that may play a critical role in the pathophysiology of dopaminergic transmission. The aim of our study was to evaluate DAT binding in a population of depressed patients with anhedonia. Single photon emission computed tomography (SPECT) with the radiotracer DATSCAN was used to evaluate DAT binding in 11 depressed patients with anhedonia and 9 healthy comparison subjects. Compared with healthy subjects, patients showed significantly lower DAT binding. No significant correlation was found between DAT binding ratios and scores on administered psychometric tests. These findings suggest an alteration in DAT density in depressed patients with anhedonia that may be a primary susceptibility factor or a secondary phenomenon to reduced dopamine concentration in the synaptic cleft.

Rhinoscintigraphy: A Simple Radioisotope Technique To Study the Mucociliary System

PURPOSE This was a radioisotope study of nasal mucociliary clearance of total and subtotal nasal obstruction. METHODS Rhinoscintigraphy was performed by insufflating 1.85 MBq (69 mCi) Tc-99m MAA in 20 patients. Six cases were regarded as the control group, because the presence of small spurs does not affect nasal patency. The remaining 14 patients had various rhinopathic conditions. Two regions of interest were selected, one in the nasal cavity and one in the pharynx. Mucociliary transport speed was calculated. RESULTS This parameter appeared to be a sensitive index for the assessment of the degree of mucociliary alteration. It showed that polyposis impairs mucociliary transport most severely, thus confirming the results of other published studies. CONCLUSIONS Rhinoscintigraphy proved to be a reliable, easily reproducible, and harmless method, so it may be used for follow-up examinations in patients who have had surgery of the nose and paranasal sinuses, and for drug therapy of rhinopathic conditions.

Diagnostic performance of iodine-123-metaiodobenzylguanidine scintigraphy in differential diagnosis between Parkinson's disease and multiple-system atrophy: A systematic review and a meta-analysis

BACKGROUND AND PURPOSE This study was designed to review the diagnostic performance of iodine-123-metaiodobenzylguanidine (MIBG) scintigraphy in differential diagnosis between Parkinsons disease (PD) and multiple-system atrophy (MSA). METHODS A comprehensive computer literature search of studies published through March 2011 regarding MIBG scintigraphy in patients with PD and MSA was performed in PubMed/MEDLINE and Embase databases. Only studies in which MIBG scintigraphy was performed for differential diagnosis between PD and MSA were selected. Pooled sensitivity and specificity of MIBG scintigraphy were presented with a 95% confidence interval (CI). The area under the ROC curve was calculated to measure the accuracy of MIBG scintigraphy in differential diagnosis between PD and MSA. RESULTS Ultimately, we identified 12 studies comprising a total of 1226 patients (593 patients with PD, 117 patients with other Lewy body disease, 129 patients with MSA, and 387 patients with other diseases). The pooled sensitivity of MIBG scintigraphy to detect PD was 89% (95% CI: 86-91%); the pooled specificity of MIBG scintigraphy to discriminate between PD and MSA was 77% (95% CI: 68-84%). The area under the ROC curve was 0.93. CONCLUSIONS MIBG scintigraphy is an accurate test for PD detection and differential diagnosis between PD and MSA; this method shows high sensitivity and adequate specificity in this field. Nevertheless, possible causes of false negative and false positive findings should be considered when interpreting the scintigraphic results.

Dopaminergic dysfunction and psychiatric symptoms in movement disorders: a 123I-FP-CIT SPECT study.

PurposePsychiatric symptoms frequently occur in patients with movement disorders. They are not a mere reaction to chronic disability, but most likely due to a combination of psychosocial factors and biochemical dysfunction underlying the movement disorder. We assessed dopamine transporter (DAT) availability by means of 123I-FP-CIT SPECT, and motor and psychiatric features in patients with Parkinson’s disease, primary dystonia and essential tremor, exploring the association between SPECT findings and symptom severity.MethodsEnrolled in the study were 21 patients with Parkinson’s disease, 14 patients with primary dystonia and 15 patients with essential tremor. The severity of depression symptoms was assessed using the Hamilton depression rating scale, anxiety levels using the Hamilton anxiety rating scale and hedonic tone impairment using the Snaith-Hamilton pleasure scale. Specific 123I-FP-CIT binding in the caudate and putamen was calculated based on ROI analysis. The control group included 17 healthy subjects.ResultsAs expected, DAT availability was significantly decreased in patients with Parkinson’s disease, whereas in essential tremor and dystonia patients it did not differ from that observed in the control group. In Parkinson’s disease patients, an inverse correlation between severity of depression symptoms and DAT availability in the left caudate was found (r = −0.63, p = 0.002). In essential tremor patients, levels of anxiety symptoms were inversely correlated with DAT availability in the left caudate (r = −0.69, p = 0.004). In dystonia patients, the severities of both anxiety and depression symptoms were inversely associated with DAT availability in the left putamen (r = −0.71, p = 0.004, and r = −0.75, p = 0.002, respectively). There were no correlations between psychometric scores and 123I-FP-CIT uptake ratios in healthy subjects.ConclusionWe found association between presynaptic dopaminergic function and affective symptoms in different movement disorders. Interestingly, the inverse correlation was present in each group of patients, supporting the fascinating perspective that common subcortical substrates may be involved in both anxiety and depression dimensions and movement disorders.

High frequency extradural motor cortex stimulation transiently improves axial symptoms in a patient with Parkinson's disease

In a primate model of Parkinsons disease (PD), the benefit of extradural motor cortex stimulation (EMCS) was associated with high‐frequency stimulation (130 Hz), whereas no significant motor improvement was achieved at 10 Hz or intermediate frequencies of stimulation. We report the case of a 72‐year‐old female patient affected by severe PD who underwent bilateral EMCS. In baseline med‐off condition the patient was unable to arise from a chair and to stand without assistance. Stimulation at 3 and 60 Hz failed to provide any improvement of symptoms, whereas, when stimulating at 130 Hz, axial akinesia and walking improved consistently: the patient, in med‐off condition, was able to arise from chair and to walk without assistance. The patient underwent two brain 99mTc‐ Ethylcysteinate Dimer‐SPECT studies: semiquantitative and Statistical Parametric Mapping revealed that the regional cerebral perfusion was significantly increased in the supplementary motor area during stimulation at 130 Hz. After five months, the benefit of EMCS gradually disappeared.

Correlation between provoked ictal SPECT and depth recordings in adult drug-resistant epilepsy patients.

Summary:  Purpose: To correlate ictal hyperperfusion single‐photon emission computed tomography (SPECT) area during provoked seizures to the epileptogenic zone (EZ), as defined by depth recordings in adult drug‐resistant patients.

Intraventricular nerve growth factor infusion: a possible treatment for neurological deficits following hypoxic-ischemic brain injury in infants

Abstract Objective and importance: Hypoxic–ischemic brain injuries in childhood are associated with poor neurological outcome. Unfortunately, no new therapeutic approaches have been proposed. Recently, animal studies show that nerve growth factor (NGF) can reduce neurological deficits following hypoxic–ischemic brain injuries. The objective of this study is to demonstrate the therapeutic effects of intraventricular NGF infusion in severe post-ischemic damage. Clinical presentation: Two infants, aged 9 and 8 months, with hypoxic–ischemic brain damage, secondary to prolonged cardiorespiratory arrest and stabilized after the conventional treatment, were treated with intraventricular NGF infusion. Before the therapy both infants were comatose with asymmetrical tetraparesis; their Glasgow Coma Scale (GCS) was 4 and 5, respectively. One month after the treatment, their GCS was 8 and 9, respectively. EEG examinations performed after the NGF infusion showed an increased alpha/theta ratio. MRI showed a reduction of malacic areas in the brain. A SPECT study, performed only in one infant, demonstrated that the NGF treatment resulted in an improvement of regional cerebral perfusion in right temporal and occipital cortices. Intervention: The drug utilized was 2.5S NGF purified and lyophilized from male mouse submaxillary glands. NGF infusion was started about 30 days after the hypoxic–ischemic brain injury. 0.1 mg NGF was administered via the external drainage catheter into the right cerebral ventricle once a day for 10 days consecutively. Conclusion: Our observations are interesting, but further studies are necessary to confirm the effects of NGF in hypoxic-ischemic brain injuries in infants.

Selective impairment of action-verb naming and comprehension in progressive supranuclear palsy

Some previous studies in brain-damaged patients suggested that neural systems in the left temporal lobe might be crucial in the production and comprehension of nouns, while analogous systems in posterior frontal cortical areas might be involved in the production and comprehension of verbs. We assessed performance on neuropsychological tasks of production and comprehension of nouns and action-verbs in 10 patients with progressive supranuclear palsy (PSP) and in 10 age-matched healthy controls. PSP patients also underwent measurements of regional cerebral blood flow by means of single photon emission computed tomography (SPECT), using 99mTc-Ethyl Cysteinate Dimer. In all PSP patients, SPECT showed a significant hypoperfusion in the inferior frontal gyrus (IFG). PSP patients performed significantly worse than controls on all lexical-semantic tasks, except for the auditory lexical decision task on nouns. Within PSP patients, however, a significantly lower performance was observed on action-verbs as compared to nouns on various lexical-semantic tasks (oral and written confrontation naming, auditory and visual single-word comprehension). Analysis of individual performance revealed heterogeneous patterns of neuropsychological impairment in different PSP patients. Despite some difficulty in drawing clear-cut conclusions about the locus of functional damage, we hypothesise that in most of our PSP patients such selective impairment in the production and in the comprehension of action-verbs could be due to semantic deficits affecting the conceptual category of actions. These findings are consistent with the hypothesis that in PSP a dysfunction of neural systems in posterior frontal cortical areas (mainly involving the IFG) critical for processing the conceptual category of actions might result in a selective impairment of production and comprehension of action-verbs.

Nigro-striatal involvement in primary progressive freezing gait: insights into a heterogeneous pathogenesis.

Primary progressive freezing gait (PPFG) is a clinical syndrome underlain by diverse neurodegenerative diseases and characterized by early occurrence of gait freezing. Either degeneration or integrity of the nigrostriatal terminals have been found by SPECT and PET studies. In this retrospective study, we evaluated (123)I-FP-CIT SPECT findings in a consecutive series of 13 PPFG patients with detailed clinical evaluation over time (mean follow-up duration: 3.1 ± 1.2 years). In all patients, (123)I-FP-CIT SPECT has been performed at the time of first clinical evaluation (1.7 ± 1.4 years after disease onset) and was compared with data from 23 age- and sex-matched healthy subjects. PPFG patients were categorized as having abnormal (n = 8) or normal (n = 5) SPECT. At disease onset, PPFG with abnormal SPECT had more frequent hypophonia, higher UPDRS-III scores and partial levodopa responsiveness. By contrast, PPFG with normal SPECT had more frequent bilateral plantar responses and no response to levodopa. At latest follow-up, initial diagnosis in the abnormal SPECT group was revised (n = 5) to progressive supranuclear palsy (n = 4) and pure akinesia with gait freezing (n = 1). Among the five patients with normal SPECT, follow-up evaluation disclosed corticobasal syndrome (n = 2) and primary lateral sclerosis (n = 1). Dopamine transporter imaging can capture the clinical heterogeneity of PPFG and might have a value to predict possible disease progression.