Brain perfusion SPECT in patients with corticobasal degeneration: analysis using statistical parametric mapping

The Significance of Vascular Pathogenesis in the Examination of Corticobasal Syndrome

Corticobasal syndrome (CBS) is a clinical entity, classified as an atypical Parkinsonism, characterized by both motor and higher cortical dysfunctions. The clinical manifestation of CBS is associated with several pathologies, among which corticobasal degeneration (CBD) is the most common. The aim of our study was to elaborate on the possible vascular pathogenesis of CBS and consider types of vascular lesions in these cases. Several cases of vascular CBS are described in the literature. The majority of presented patients were affected by internal carotid artery (ICA) stenosis and ischemic strokes; few cases were associated with vascular malformations or autoimmune diseases. Vascular CBS is preceded by an abrupt onset. The clinical manifestation does not significantly differ with non-vascular CBS. Patients with vascular CBS are usually elderly; often with coexistent hypertension, dyslipidemia and diabetes mellitus. Inferring from our observations, cerebral hypoperfusion can play a significant role in neuropathological changes in neurodegenerative diseases. To the best of our knowledge paper is the first comprehensive review of vascular CBS and we are positive that our observations show that further research concerning the vascular pathogenesis of tauopathy atypical Parkinsonism is required.

Anesthetic management in corticobasal degeneration with central sleep apnea: A case report

Corticobasal degeneration (CBD) is a rare neurodegenerative disease characterized by dystonia, cognitive deficits, and an asymmetric akinetic-rigid syndrome. Little information is available regarding anesthetic management for CBD patients. Our patient was a 55-year-old man with CBD complicated by central sleep apnea (CSA). Due to the risk of perioperative breathing instability associated with anesthetic use, a laryngeal mask airway was used during anesthesia with propofol. Spontaneous respiration was stable under general anesthesia. However, respiratory depression occurred following surgery, necessitating insertion of a nasopharyngeal airway. Since no respiratory depression had occurred during maintenance of the airway using the laryngeal mask, we suspected an upper airway obstruction caused by displacement of the tongue due to residual propofol. Residual anesthetics may cause postoperative respiratory depression in patients with CBD. Therefore, continuous postoperative monitoring of SpO₂ and preparations to support postoperative ventilation are necessary.

Differential diagnosis of parkinsonian syndromes using dopamine transporter and perfusion SPECT

OBJECTIVE

We aimed to assess whether a combined analysis of dopamine transporter (DAT)- and perfusion-SPECT images (or either) could: (1) distinguish atypical parkinsonian syndromes (APS) from Lewy body diseases (LBD; majority Parkinson disease [PD]), and (2) differentiate among APS subgroups (progressive supranuclear palsy [PSP], corticobasal syndrome [CBS], and multiple system atrophy [MSA]).

METHODS

We recruited consecutive patients with neurodegenerative parkinsonian syndromes (LBD, n = 46; APS, n = 33). Individual [¹²³I]FP-CIT- and [¹²³I]iodoamphetamine-SPECT images were coregistered onto anatomical MRI segmented into brain regions. Striatal DAT activity and regional perfusion were extracted from each brain region for each patient and submitted to logistic regression analyses. Stepwise procedures were used to select predictors that should be included in the models to distinguish APS from LBD, and differentiate among the APS subgroups. Receiver-operating characteristic (ROC) analyses were performed to measure diagnostic power. Leave-one-out cross-validation (LOOCV) was performed to evaluate the diagnostic accuracy.

RESULTS

The model to discriminate APS from LBD showed that the area under the ROC curve (AUC) was 0.923, while the total diagnostic accuracy (TDA) was 86.1% in LOOCV. In the model to distinguish PSP, CBS, and MSA from LBD, the AUC/TDA values were 0.978/94.6%, 0.978/87.0%, and 0.880/80.3%, respectively. In the model to differentiate between CBS and MSA, MSA and PSP, and PSP and CBS, the AUC/TDA values were 0.967/91.3%, 0.920/88.0%, 0.875/77.8%, respectively.

CONCLUSION

An image-based automated classification using striatal DAT activity and regional perfusion patterns provided a good performance in the differential diagnosis of neurodegenerative parkinsonian syndromes without clinical information.

Brain Perfusion in Corticobasal Syndrome with Progressive Aphasia

Background

Brain perfusion may differ between patients with corticobasal syndrome (CBS) with and without aphasia.

Methods

Twenty-six (9 males and 17 females; mean age 76 ± 5.3 years) patients with CBS were enrolled in the study. Brain MRI and single-photon emission computed tomography were performed in all subjects. Language was evaluated using the Standard Language Test of Aphasia. The patients were divided into two subgroups according to the presence or absence of progressive aphasia. Differences in the regional cerebral blood flow (rCBF) between the two groups were detected based on voxel-by-voxel group analysis using Statistical Parametric Mapping 8.

Results

All patients exhibited asymmetric motor symptoms and signs, including limb apraxia, bradykinesia, and akinetic rigidity. Of 26 patients, 9 had a clinically obvious language disturbance, characterized as nonfluent aphasia. Almost all CBS patients with aphasia exhibited cortical atrophy predominantly in the left frontal and temporal lobes with widening of the Sylvian fissure on MRI. The rCBF in the left middle frontal gyrus differed significantly between CBS patients with and without aphasia.

Conclusion

CBS patients with aphasia exhibit motor symptoms predominantly on the right side and cortical atrophy mainly in the left perisylvian cortices. In particular, left frontal dysfunction might be related to nonfluent aphasia in CBS.

Therapeutic interventions in parkinsonism: Corticobasal degeneration

Corticobasal degeneration (CBD) is a progressive neurodegenerative disorder resulting from pathological accumulation of tau protein and is included in the spectrum of Atypical Parkinsonism. The typical clinical phenotype of CBD is characterized by the Corticobasal syndrome (CBS). In recent years it has become clear that the clinical picture of CBS may be caused by different pathological conditions, resulting in frequent misdiagnosis. CBD has high morbidity and poor prognosis with no effective therapies. In this review, we will discuss the symptomatic treatment, the palliative care and the disease modifying strategies currently in use. Symptomatic treatment in patients with CBD may sometimes be useful for improving motor (parkinsonism, dystonia and myoclonus) and non-motor (cognitive-behavioral) symptoms, but the effects are often unsatisfactory. In addition, non-pharmacological strategies and palliative care are useful integrating components of the multidisciplinary therapeutic approach for patients with CBD. Despite many efforts, a disease-modifying treatment is still unavailable for CBD.

Diagnoses behind patients with hard-to-classify tremor and normal DaT-SPECT: a clinical follow up study

The [¹²³I]ioflupane—a dopamine transporter radioligand—SPECT (DaT-SPECT) has proven to be useful in the differential diagnosis of tremor. Here, we investigate the diagnoses behind patients with hard-to-classify tremor and normal DaT-SPECT. Therefore, 30 patients with tremor and normal DaT-SPECT were followed up for 2 years. In 18 cases we were able to make a diagnosis. The residual 12 patients underwent a second DaT-SPECT, were then followed for additional 12 months and thereafter the diagnosis was reconsidered again. The final diagnoses included cases of essential tremor, dystonic tremor, multisystem atrophy, vascular parkinsonism, progressive supranuclear palsy, corticobasal degeneration, fragile X–associated tremor ataxia syndrome, psychogenic parkinsonism, iatrogenic parkinsonism and Parkinson's disease. However, for 6 patients the diagnosis remained uncertain. Larger series are needed to better establish the relative frequency of the different conditions behind these cases.

Cholinergic imaging in corticobasal syndrome, progressive supranuclear palsy and frontotemporal dementia

Corticobasal syndrome, progressive supranuclear palsy and frontotemporal dementia are all part of a disease spectrum that includes common cognitive impairment and movement disorders. The aim of this study was to characterize brain cholinergic deficits in these disorders. We measured brain acetylcholinesterase activity by [11C] N-methylpiperidin-4-yl acetate and positron emission tomography in seven patients with corticobasal syndrome (67.6+/-5.9 years), 12 with progressive supranuclear palsy (68.5+/-4.1 years), eight with frontotemporal dementia (59.8+/-6.9 years) and 16 healthy controls (61.2+/-8.5 years). Two-tissue compartment three-parameter model and non-linear least squares analysis with arterial input function were performed. k3 value, an index of acetylcholinesterase activity, was calculated voxel-by-voxel in the brain of each subject. The k3 images in each disease group were compared with the control group by using Statistical Parametric Mapping 2. Volume of interest analysis was performed on spatially normalized k3 images. The corticobasal syndrome group showed decreased acetylcholinesterase activity (k3 values) in the paracentral region, frontal, parietal and occipital cortices (P<0.05, cluster corrected). The group with progressive supranuclear palsy had reduced acetylcholinesterase activity in the paracentral region and thalamus (P<0.05, cluster corrected). The frontotemporal dementia group showed no significant differences in acetylcholinesterase activity. Volume of interest analysis showed mean cortical acetylcholinesterase activity to be reduced by 17.5% in corticobasal syndrome (P<0.001), 9.4% in progressive supranuclear palsy (P<0.05) and 4.4% in frontotemporal dementia (non-significant), when compared with the control group. Thalamic acetylcholinesterase activity was reduced by 6.4% in corticobasal syndrome (non-significant), 24.0% in progressive supranuclear palsy (P<0.03) and increased by 3.3% in frontotemporal dementia (non-significant). Both corticobasal syndrome and progressive supranuclear palsy showed brain cholinergic deficits, but their distribution differed somewhat. Significant brain cholinergic deficits were not seen in frontotemporal dementia, which may explain the unresponsiveness of this condition to cholinergic modulation therapy.

Asymmetrical cerebral perfusion demonstrated by noninvasive arterial spin-labeling perfusion imaging in a patient with corticobasal degeneration

This is to report arterial spin-labeling (ASL) regional cerebral blood flow (rCBF) mapping findings in a case of corticobasal degeneration (CBD). A 68-year-old man gradually developed limb-kinetic apraxia, myoclonus, and rigidity in the left hand and was diagnosed as having CBD. Magnetic resonance imaging and single photon emission computed tomography revealed atrophy and decreased blood flow, respectively, in the right hemisphere, findings that were compatible with CBD. In addition, ASL rCBF mapping demonstrated asymmetrical hypoperfusion areas in locations typical for CBD, proving its potential usefulness for routine clinical differential diagnosis.

[Classification of parkinsonian syndromes via factorial discriminant analysis of brain SPECT data]

INTRODUCTION

The objective was to assess the value of single photon emission computerized tomography (SPECT) and factorial discriminant analysis (FDA) in the differential diagnosis of Parkinson's disease (PD), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD).

PATIENTS AND METHODS

Sixty-two patients with clinical diagnoses of either CBD, PSP or PD were studied using brain HmPaO-SPECT. Thirteen pairs of regions of interest (ROIs) were drawn on the slices located 50mm and 90mm above the canthomeatal plane. Twenty-six uptake indices and 13 asymmetry indices were determined. FDA was performed in order to determine whether or not the patients could be classified into the correct clinical group on the basis of SPECT data alone. The most discriminant parameters were used to generate two predictive scores, which were tested in a second group of 15 patients.

RESULTS

FDA of all 39 variables correctly classified all the patients. A subset of 10 variables was used to build predictive scores, which correctly classified 90% of PD patients, 100% of PSP patients and 86% of CBD patients. When tested in the validation group of 15 patients, these predictive scores correctly classified 87% of the individuals. The frontal medial, temporoparietal and parietal regions were the most discriminant.

CONCLUSION

Using SPECT data alone, this study enabled us to distinguish between PD, PSP and CBD in patients with clear clinical presentations of the diseases in question. This novel, statistical approach provides reliable information. However, a prospective study dealing with de novo parkinsonian syndromes will be necessary.

Parkinsonian syndromes

The term parkinsonian syndromes refers to a group of disorders whose clinical features overlap those of idiopathic Parkinson's disease. The four major entities include three important neurodegenerations, multiple system atrophy, progressive supranuclear palsy, and corticobasal degeneration, and a lacunar cerebrovascular disorder, vascular parkinsonism. This article reviews the epidemiology, pathology, clinical features, diagnosis, and management of these disorders.

Clinical characteristics of corticobasal syndrome amongst Chinese in Taiwan

This study reviewed the clinical characteristics of nine patients, the female-to-male ratio being 2 (6/3), with corticobasal syndrome (CBS) from 2001 to 2006. The mean age of onset was 60.33+/-5.20 years. The most popular symptom was rigidity (100%), followed by bradykinesia (88.89%), apraxia (88.89%) and dystonia (66.67%). The common presentations in neuropsychological assessment included frontal dysfunction (88.89%), disorientation (66.67%), memory impairments (66.67%) and visuospecial defects (66.67%). Single proton emission-computed tomography (CT) showed hypoperfusion at contralateral basal ganglia, thalamic, parietal or temporal region in eight of nine patients. This investigation suggests that functional neuroimages and neuropsychological tests are useful tools for the diagnosis of CBS.

Corticobasal degeneration and Parkinson's disease assessed by HmPaO SPECT: The utility of factorial discriminant analysis

The diagnosis of corticobasal degeneration (CBD) is difficult despite the existence of some typical clinical features. Single photon emission computerized tomography (SPECT) in CBD presents an original pattern (with asymmetric hypoperfusion in pre- and retrorolandic regions) that could facilitate the differential diagnosis of CBD relative to the other degenerative parkinsonian syndromes. The objective of our study was to compare the regional cerebral blood flow measurements studied by SPECT in both CBD and Parkinson's disease (PD) using a multivariate procedure. Twenty-one patients with probable CBD and 20 patients with probable PD underwent brain (99m)Tc HmPaO SPECT. We used factorial discriminant analysis (FDA) to study the relative fixation of 26 regions of interest (ROIs) drawn on two transverse slices, together with the asymmetry indexes of 13 pairs of ROIs. FDA performed using the full set of parameters classified all the patients correctly. In order to classify the patients more easily, a predictive score using a selection of parameters was established. The most discriminating ROIs were the temporoinsular, temporoparietal, and frontal medial regions. We believe that this semiautomatic classification may be a precious tool for reinforcing the current clinical differential diagnosis of CBD and PD.

Neuroimaging of Parkinson's disease and atypical parkinsonism

The basal ganglia and its associated circuitry can be assessed with a variety of neuroimaging methods that can provide information regarding specific neurotransmitter systems, the functional activity of brain regions, and the structural integrity of these regions. In Parkinson's disease (PD) and related atypical parkinsonian syndromes (APS), these imaging methods may be useful for many reasons, including aiding in differential diagnosis and measuring the efficacy of new therapies. This paper reviews recent developments in the application of neuroimaging to the assessment of PD and related APS.