Parkinson Disease: Hurtig HI

Goldmann Gross R, Siderowf A, Hurtig HI. · Parkinson's Disease and Movement Disorders Center, Department of Neurology, University of Pennsylvania Health System, Philadelphia, PA, USA. · Neurosignals. · Pubmed #18097157 No free full text.

Abstract: Parkinson's disease (PD) is classically thought of as a movement disorder characterized by tremor, rigidity and postural instability. Nevertheless, there is growing recognition of prominent cognitive impairment in PD and related disorders, which is responsible for substantial disability in these patients. This review will focus on cognitive impairment associated with Lewy body pathology, including PD with dementia (PDD) and dementia with Lewy bodies (DLB). We will review the epidemiology, clinical evaluation, underlying mechanisms and treatment of cognitive impairment in these patients. Despite differences between PDD and DLB, there is clinical, neuropathological and radiological overlap between these disorders, supporting the view that they represent a spectrum of disease. These observations suggest that common targets for diagnosis and treatment of these disorders can be identified.

Weintraub D, Hurtig HI. · Department of Psychiatry, University of Pennsylvania, 3535 Market St., Rm. 3003, Philadelphia, PA 19104, USA. · Am J Psychiatry. · Pubmed #17898337 links to  free full text

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Elman LB, Houghton DJ, Wu GF, Hurtig HI, Markowitz CE, McCluskey L. · ALS Association Center, University of Pennsylvania, Philadelphia, Pennsylvania, USA. · J Palliat Med. · Pubmed #17472516 No free full text.

Abstract: BACKGROUND: Amyotrophic lateral sclerosis, Parkinson's disease, atypical parkinsonian syndromes, and multiple sclerosis are progressive neurologic disorders that cumulatively afflict a large number of people. Effective end-of-life palliative care depends upon an understanding of the clinical aspects of each of these disorders. OBJECTIVES: The authors review the unique and overlapping aspects of each of these disorders with an emphasis upon the clinical management of symptoms. Design: The authors review current management and the supporting literature. CONCLUSIONS: Clinicians have many effective therapeutic options to choose from when managing the symptoms produced by these disorders.

Lippa CF, Duda JE, Grossman M, Hurtig HI, Aarsland D, Boeve BF, Brooks DJ, Dickson DW, Dubois B, Emre M, Fahn S, Farmer JM, Galasko D, Galvin JE, Goetz CG, Growdon JH, Gwinn-Hardy KA, Hardy J, Heutink P, Iwatsubo T, Kosaka K, Lee VM, Leverenz JB, Masliah E, McKeith IG, Nussbaum RL, Olanow CW, Ravina BM, Singleton AB, Tanner CM, Trojanowski JQ, Wszolek ZK, Anonymous00243. · Department of Neurology, Drexel University College of Medicine, Philadelphia, PA 19102, USA. · Neurology. · Pubmed #17353469 No free full text.

Abstract: For more than a decade, researchers have refined criteria for the diagnosis of dementia with Lewy bodies (DLB) and at the same time have recognized that cognitive impairment and dementia occur commonly in patients with Parkinson disease (PD). This article addresses the relationship between DLB, PD, and PD with dementia (PDD). The authors agreed to endorse "Lewy body disorders" as the umbrella term for PD, PDD, and DLB, to promote the continued practical use of these three clinical terms, and to encourage efforts at drug discovery that target the mechanisms of neurodegeneration shared by these disorders of alpha-synuclein metabolism. We concluded that the differing temporal sequence of symptoms and clinical features of PDD and DLB justify distinguishing these disorders. However, a single Lewy body disorder model was deemed more useful for studying disease pathogenesis because abnormal neuronal alpha-synuclein inclusions are the defining pathologic process common to both PDD and DLB. There was consensus that improved understanding of the pathobiology of alpha-synuclein should be a major focus of efforts to develop new disease-modifying therapies for these disorders. The group agreed on four important priorities: 1) continued communication between experts who specialize in PDD or DLB; 2) initiation of prospective validation studies with autopsy confirmation of DLB and PDD; 3) development of practical biomarkers for alpha-synuclein pathologies; 4) accelerated efforts to find more effective treatments for these diseases.

Chou KL, Hurtig HI, Stern MB, Colcher A, Ravina B, Newberg A, Mozley PD, Siderowf A. · Parkinson's Disease and Movement Disorders Center, University of Pennsylvania School of Medicine, Pennsylvania Hospital, 330 South Ninth Street, Philadelphia, PA 19107, USA. · Parkinsonism Relat Disord. · Pubmed #15261880 No free full text.

Abstract: We evaluated the diagnostic accuracy of SPECT imaging using [(99m)Tc]TRODAT-1 (TRODAT), a relatively inexpensive technetium-labeled dopamine transporter ligand, in distinguishing 29 patients with early PD from 38 healthy volunteers. Mean TRODAT uptake values were significantly decreased in the caudate (p=0.0097) and anterior and posterior putamen (p < 0.0001) of PD patients compared to controls. Using the posterior putamen as the main region of interest resulted in the greatest accuracy (sensitivity 0.79, specificity 0.92). These findings show that TRODAT imaging can accurately differentiate early PD patients from controls and has the potential to improve the diagnosis of patients with early signs of PD.

Grossman M, Cooke A, DeVita C, Lee C, Alsop D, Detre J, Gee J, Chen W, Stern MB, Hurtig HI. · Department of Neurology, University of Pennsylvania Medical Center, Philadelphia, USA. · Neurology. · Pubmed #12629232 No free full text.

Abstract: BACKGROUND: Sentence comprehension requires linguistic processing as well as cognitive resources such as working memory (WM) and information-processing speed (IPS). The authors hypothesize that sentence comprehension difficulty in patients with mild PD is due to degradation of the large-scale neural network that supports cognitive resources during sentence processing. OBJECTIVE: To understand the neural basis for sentence comprehension difficulty in PD. METHOD: Regional brain activity with blood oxygenation level-dependent fMRI was monitored while seven PD patients and nine healthy seniors answered a simple probe about written sentences that vary in their grammatical and cognitive resource properties. RESULTS: Healthy seniors recruited posterolateral temporal and ventral inferior frontal regions of the left hemisphere, brain regions associated with grammatical processing that were also activated by PD patients. Healthy seniors also recruited left dorsal inferior frontal, right posterolateral temporal, and striatal regions that are associated with cognitive resources during sentence processing. Direct contrasts showed that striatal, anteromedial prefrontal, and right temporal regions are recruited to a significantly lesser degree in PD, but these patients have increased activation of right inferior frontal and left posterolateral temporal-parietal areas during sentence comprehension. CONCLUSION: These findings associate impaired sentence comprehension in PD with interruption of a large-scale network important for cognitive resources during sentence processing. These results also imply compensatory up-regulation of cortical activity that allows patients with mild PD to maintain sentence comprehension accuracy.

Simuni T, Jaggi JL, Mulholland H, Hurtig HI, Colcher A, Siderowf AD, Ravina B, Skolnick BE, Goldstein R, Stern MB, Baltuch GH. · Parkinson's Disease and Movement Disorders Center, Pennsylvania Hospital, Philadelphia, USA. · J Neurosurg. · Pubmed #11990805 No free full text.

Abstract: OBJECT: Palliative neurosurgery has reemerged as a valid therapy for patients with advanced Parkinson disease (PD) that is complicated by severe motor fluctuations. Despite great enthusiasm for long-term deep brain stimulation (DBS) of the subthalamic nucleus (STN), existing reports on this treatment are limited. The present study was designed to investigate the safety and efficacy of bilateral stimulation of the STN for the treatment of PD. METHODS: In 12 patients with severe PD, electrodes were stereotactically implanted into the STN with the assistance of electrophysiological conformation of the target location. All patients were evaluated preoperatively during both medication-off and -on conditions, as well as postoperatively at 3, 6, and 12 months during medication-on and -off states and stimulation-on and -off conditions. Tests included assessments based on the Unified Parkinson's Disease Rating Scale (UPDRS) and timed motor tests. The stimulation effect was significant in patients who were in the medication-off state, resulting in a 47% improvement in the UPDRS Part III (Motor Examination) score at 12 months, compared with preoperative status. The benefit was stable for the duration of the follow-up period. Stimulation produced no additional benefit during the medication-on state, however, when compared with patient preoperative status. Significant improvements were made in reducing dyskinesias, fluctuations, and duration of off periods. CONCLUSIONS: This study demonstrates that DBS of the STN is an effective treatment for patients with advanced, medication-refractory PD. Deep brain stimulation of the STN produced robust improvements in motor performance in these severely disabled patients while they were in the medication-off state. Serious adverse events were common in this cohort; however, only two patients suffered permanent sequelae.

Grossman M, Zurif E, Lee C, Prather P, Kalmanson J, Stern MB, Hurtig HI. · Department of Neurology, University of Pennsylvania School of Medicine, Philadelphia 19104-4283, USA. · Neuropsychology. · Pubmed #11949709 No free full text.

Abstract: This study tests the hypothesis that sentence comprehension difficulty in Parkinson's disease (PD) is related in part to altered information processing speed that plays a crucial role in grammatical processing. The authors measured information processing speed in 32 PD patients without dementia using a lexical list-priming paradigm in which the interstimulus interval (ISI) between the prime and the target varied. Sentence comprehension accuracy was also assessed in 22 of these patients. Sentence comprehension accuracy for object-relative center-embedded sentences was impaired in a subgroup of PD patients. This subgroup of PD patients primed at an abnormally long ISI. Similarly, only PD patients who primed at a long ISI had greater difficulty understanding sentences with an object-relative clause than a subject-relative clause. Findings suggest that slowed information processing speed contributes to sentence comprehension difficulty in PD.

Nazem S, Siderowf AD, Duda JE, Have TT, Colcher A, Horn SS, Moberg PJ, Wilkinson JR, Hurtig HI, Stern MB, Weintraub D. · Department of Psychiatry, University of Pennsyvania, Philadelphia, USA. · J Am Geriatr Soc. · Pubmed #19170786 No free full text.

Abstract: OBJECTIVES: To examine Montreal Cognitive Assessment (MoCA) performance in patients with Parkinson's disease (PD) with "normal" global cognition according to Mini-Mental State Examination (MMSE) score. DESIGN: A cross-sectional comparison of the MoCA and the MMSE. SETTING: Two movement disorders centers at the University of Pennsylvania and the Philadelphia Veterans Affairs Medical Center. PARTICIPANTS: A convenience sample of 131 patients with idiopathic PD who were screened for cognitive and psychiatric complications. MEASUREMENTS: Subjects were administered the MoCA and MMSE, and only subjects defined as having a normal age- and education-adjusted MMSE score were included in the analyses (N=100). As previously recommended in patients without PD, a MoCA score less than 26 was used to indicate the presence of at least mild cognitive impairment (MCI). RESULTS: Mean MMSE and MoCA scores+/-standard deviation were 28.8+/-1.1 and 24.9+/-3.1, respectively. More than half (52.0%) of subjects with normal MMSE scores had cognitive impairment according to their MoCA score. Impairments were seen in numerous cognitive domains, including memory, visuospatial and executive abilities, attention, and language. Predictors of cognitive impairment on the MoCA using univariate analyses were male sex, older age, lower educational level, and greater disease severity; older age was the only predictor in a multivariate model. CONCLUSION: Approximately half of patients with PD with a normal MMSE score have cognitive impairment based on the recommended MoCA cutoff score. These results suggest that MCI is common in PD and that the MoCA is a more sensitive instrument than the MMSE for its detection.

Covy JP, Yuan W, Waxman EA, Hurtig HI, Van Deerlin VM, Giasson BI. · Department of Pharmacology, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6084, USA. · Mov Disord. · Pubmed #19006185 No free full text.

Abstract: Mutations in LRRK2 are the single most common known cause of Parkinson's disease (PD). Two new PD patients with LRRK2 mutation were identified from a cohort with extensive postmortem assessment. One of these patients harbors the R793M mutation and presented with the typical clinical and pathological features of PD. A novel L1165P mutation was identified in a second patient. This patient had the classical and pathological features of PD, but additionally developed severe neuropsychological symptoms and dementia associated with abundant neurofibrillary tangles in the hippocampal formation; features consistent with a secondary diagnosis of tangle-predominant dementia. alpha-Synuclein-containing pathological inclusions in these patients also were highly phosphorylated at Ser-129, similar to other patients with idiopathic PD. These two PD patients also were characterized by the presence of occasional cytoplasmic TDP-43 inclusions in the temporal cortex, a finding that was not observed in three other patients with the G2019S mutation in LRRK2. These findings extend the clinical and pathological features that may be associated with LRRK2 mutations.

Mamikonyan E, Moberg PJ, Siderowf A, Duda JE, Have TT, Hurtig HI, Stern MB, Weintraub D. · Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA. · Parkinsonism Relat Disord. · Pubmed #18595765 links to  free full text

Abstract: PURPOSE: Cognitive impairment occurs in the majority of Parkinson's disease (PD) patients, but little is known about detection of mild cognitive impairment (MCI) in this population. We report on the frequency and characteristics of cognitive deficits in PD patients with intact global cognition based on Mini-Mental State Examination (MMSE) performance. METHODS: One hundred and six PD patients with normal age- and education-adjusted MMSE scores (mean [SD] score=29.1 [1.1]) were administered standardized neuropsychological tests assessing memory, executive function, and attention. Impairment on a cognitive domain was a low score (i.e., >or=1.5 SD below the published normative mean) on at least two measures or tests (for memory and executive abilities) or a single measure (for attention). RESULTS: Mild cognitive impairment was found in 29.2% of PD patients, with 17.9% demonstrating single domain and 11.3% multiple domain impairment. Memory and attention impairment were most common (15.1% and 17.0%, respectively), followed by executive impairment (8.5%). Depending on the measure of disease severity chosen, increasing age and disease severity, anti-anxiety medication use, and a suggestion for increasing severity of daytime sleepiness were independent predictors of cognitive impairment. CONCLUSIONS: Cognitive deficits are common in PD patients with "normal" cognition based on MMSE performance, suggesting that MCI is under-recognized in clinical practice due to routine use of insensitive screening instruments. In contrast with some previous reports, early memory impairment may be as common as either executive or attentional deficits in PD. In addition, psychiatric medication use and daytime sleepiness may be reversible or treatable contributors to cognitive impairment.

Chen-Plotkin AS, Yuan W, Anderson C, McCarty Wood E, Hurtig HI, Clark CM, Miller BL, Lee VM, Trojanowski JQ, Grossman M, Van Deerlin VM. · Center for Neurodegenerative Disease Research, Institute on Aging and Department of Pathology and Laboratory Medicine, University of Pennsylvania Health System, Philadelphia, PA 19104, USA. · Neurology. · Pubmed #17914064 No free full text.

Abstract: BACKGROUND: Mutations in the LRRK2 gene are an important cause of familial and nonfamilial parkinsonism. Despite pleomorphic pathology, LRRK2 mutations are believed to manifest clinically as typical Parkinson disease (PD). However, most genetic screens have been limited to PD clinic populations. OBJECTIVE: To clinically characterize LRRK2 mutations in cases recruited from a spectrum of neurodegenerative diseases. METHODS: We screened for the common G2019S mutation and several additional previously reported LRRK2 mutations in 434 individuals. A total of 254 patients recruited from neurodegenerative disease clinics and 180 neurodegenerative disease autopsy cases from the University of Pennsylvania brain bank were evaluated. RESULTS: Eight cases were found to harbor a LRRK2 mutation. Among patients with a mutation, two presented with cognitive deficits leading to clinical diagnoses of corticobasal syndrome and primary progressive aphasia. CONCLUSION: The clinical presentation of LRRK2-associated neurodegenerative disease may be more heterogeneous than previously assumed.

Liang GS, Chou KL, Baltuch GH, Jaggi JL, Loveland-Jones C, Leng L, Maccarone H, Hurtig HI, Colcher A, Stern MB, Kleiner-Fisman G, Simuni T, Siderowf AD. · The Parkinson's Institute, Sunnyvale, CA, USA. · Stereotact Funct Neurosurg. · Pubmed #17063043 No free full text.

Abstract: BACKGROUND: In patients with advanced Parkinson's disease (PD), deep brain stimulation (DBS) of the subthalamic nucleus (STN) has been shown to improve motor function and decrease medication requirements in the short term. However, the long-term benefits of DBS are not yet established. OBJECTIVE: It was the aim of this study to evaluate long-term outcomes of patients with PD treated with bilateral DBS of the STN. DESIGN AND METHODS: Thirty-three subjects who had bilateral STN DBS were followed prospectively after surgery. We evaluated subjects, using the Unified Parkinson's Disease Rating Scale (UPDRS), preoperatively, 12 months after surgery and at a long-term follow-up visit. Ratings were performed on and off dopaminergic medications. We compared postoperative UPDRS scores, dyskinesia ratings and medication dosages with preoperative values. RESULTS: Twenty-seven subjects had evaluations beyond 18 months (median 33.7 months). Total UPDRS scores in the 'medication-off' state were improved by 37% (p < 0.001) at 12 months and 17.7% (p = 0.0051) at the long-term evaluation. Medication-off state UPDRS part III scores were significantly improved at both 1 year and at the last evaluation (37.6 and 29.3%; p < 0.001). Dopaminergic medication requirements were decreased by 35.3% (p < 0.001) during the first postoperative year and remained below preoperative levels at the long-term evaluation. Average duration of 'off' time remained decreased by about 40% at both 1 year and at the time of last evaluation. Subjects had a sustained reduction in dyskinesia severity (88.6% at 1 year and 68.8% at last evaluation). CONCLUSIONS: In this cohort of subjects with advanced PD, bilateral STN stimulation improved 'off' medication motor function, reduced time spent in the medication-off state and reduced medication requirements for up to 4 years after surgery. We conclude that STN DBS is an effective long-term therapy for selected patients with advanced PD.

Goker-Alpan O, Giasson BI, Eblan MJ, Nguyen J, Hurtig HI, Lee VM, Trojanowski JQ, Sidransky E. · Section on Molecular Neurogenetics, Medical Genetics Branch, National Human Genome Research Institute, NIH, Bethesda, MD 20892-3708, USA. · Neurology. · Pubmed #16790605 No free full text.

Abstract: The synucleinopathies are neurodegenerative disorders defined by inclusions composed of aberrantly fibrillized alpha-synuclein, but factors contributing to this process remain largely unknown. The authors examined the glucocerebrosidase gene in 75 autopsy specimens with different synucleinopathies and identified mutations in 23% of cases of dementia with Lewy bodies, expanding on previous findings in subjects with Parkinson disease. Mutations in this lysosomal protein may interfere with the clearance or promote aggregation of alpha-synuclein.

Giasson BI, Covy JP, Bonini NM, Hurtig HI, Farrer MJ, Trojanowski JQ, Van Deerlin VM. · Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6084, USA. · Ann Neurol. · Pubmed #16437584 No free full text.

Abstract: OBJECTIVE: Mutations in leucine-rich repeat kinase 2 (LRRK2) recently have been identified as the most common genetic cause of late-onset sporadic and familial Parkinson's disease (PD). The studies herein explore the biological and pathological properties of Lrrk2. METHODS: Genetic analysis was performed to identify autopsied patients with the most common Lrrk2 mutation (G2019S). Using an antibody specific to Lrrk2, the biochemical and immunocytochemical distribution of Lrrk2 was assessed. RESULTS: Three patients with the G2019S Lrrk2 mutation were identified. Two patients demonstrated classic PD with Lewy bodies, although concurrent pathological changes consistent with Alzheimer's disease were also present in one of these individuals. The third patient was characterized by parkinsonism without Lewy bodies but demonstrated dystrophic neurites in the substantia nigra intensely stained for Lrrk2. Lrrk2 accumulations were unique to this patient and Lrrk2 was not detected in other types of pathological inclusions. Biochemical analysis showed that Lrrk2 is predominantly a soluble approximately 250 kDa cytoplasmic protein expressed throughout the brain but also in many other organs. INTERPRETATION: The reasons for the selective predisposition of patients with mutations in LRRK2 to develop parkinsonism remains unclear, but Lrrk2 mutations may prime select neuronal populations to cellular insults that can lead to aberrant protein aggregation.

Chou KL, Hurtig HI, Jaggi JL, Baltuch GH, Pelchat RJ, Weintraub D. · Department of Clinical Neurosciences, Brown University Medical School, Providence, RI, USA. · Parkinsonism Relat Disord. · Pubmed #15994113 No free full text.

Abstract: We report a patient with advanced Parkinson's disease (PD) who developed a recurrence of major depression with psychotic features after bilateral subthalamic nucleus (STN) deep brain stimulation (DBS) surgery. Electroconvulsive therapy (ECT) dramatically improved the depression without shifting electrode position or damaging the DBS hardware. This case suggests that ECT can be a safe and effective option for severe depression in PD patients treated with STN DBS.

Siderowf A, Newberg A, Chou KL, Lloyd M, Colcher A, Hurtig HI, Stern MB, Doty RL, Mozley PD, Wintering N, Duda JE, Weintraub D, Moberg PJ. · Parkinson Disease and Movement Disorders Center, Department of Neurology, University of Pennsylvania, Philadelphia, USA. · Neurology. · Pubmed #15911797 No free full text.

Abstract: BACKGROUND: In vivo imaging of the dopamine transporter with [99mTc]TRODAT-1 (TRODAT) and olfactory testing have both been proposed as potential biomarkers in Parkinson disease (PD). OBJECTIVE: To evaluate the relationship between TRODAT SPECT imaging, odor identification skills, and motor function in patients with early PD. METHODS: Twenty-four patients with a clinical diagnosis of early-stage PD (mean Hoehn & Yahr stage = 1.4) underwent TRODAT imaging, Unified PD Rating Scale (UPDRS) ratings of motor function, and administration of the University of Pennsylvania Smell Identification Test (UPSIT). Brain images were obtained using a standardized processing protocol and specific uptake ratios for striatal regions of interest were calculated. Partial correlations between the imaging indices, disease duration, UPSIT scores, and UPDRS motor scores were then calculated. RESULTS: UPSIT scores were correlated with TRODAT uptake in the striatum as a whole (r = 0.66, p = 0.001). The putamen showed the strongest correlation with the UPSIT (r = 0.74; p < 0.001). The correlation between dopamine transporter density in the caudate and UPSIT was moderate (r = 0.36, p = 0.11), but was not significant. CONCLUSIONS: Olfactory function is highly correlated with dopamine transporter imaging abnormalities in early Parkinson disease (PD). Further studies are warranted to determine whether changes over time in these two measures are also correlated in early PD.

Jaggi JL, Umemura A, Hurtig HI, Siderowf AD, Colcher A, Stern MB, Baltuch GH. · Parkinson's Disease and Movement Disorders Center at Pennsylvania Hospital, Department of Neurology, University of Pennsylvania, Philadelphia 19107, USA. · Stereotact Funct Neurosurg. · Pubmed #15305083 No free full text.

Abstract: OBJECTIVE: Over the last decade neurosurgery has reemerged as a valid therapy for patients with advanced Parkinson's disease. Previously, we have addressed safety and efficacy of subthalamic nucleus (STN) deep brain stimulation (DBS). In this study, we extended these observations and analyzed factors that affect surgical outcome and its predictive value. METHODS: Thirty-nine patients were enrolled in an open-label prospective protocol designed to evaluate safety and efficacy of bilateral STN DBS in patients with advanced Parkinson's disease between January 1999 and July 2002. Electrodes were stereotactically implanted with electrophysiological conformation of the target location. All patients were evaluated in the medication 'off' and 'on' state preoperatively and at 3, 6, and 12 months after surgery in medication 'on' and 'off' as well as in the stimulation 'off' and 'on' state. Tests included Unified Parkinson's Disease Rating Scales (UPDRS) as well as timed tests. All data was analyzed by means of Analysis of Variance. For outcome prediction, correlation and linear regression analyses were utilized. Stimulation produced significant improvements in all 'off' mediation conditions, resulting in a 42% improvement in UPDRS III score at 12 months compared to the preoperative status. Stimulation in conjunction with medication did not produce any significant change when compared to the preoperative medication 'on' state. Dyskinesia, motor fluctuations, and duration of 'off' periods were significantly reduced with stimulation. Significant outcome predictor variables were age, preoperative percent change of UPDRS III score from medication 'off' to medication 'on' state, and the duration of disease. CONCLUSIONS: Bilateral STN DBS produces robust improvements in parkinsonian motor symptoms. Surgical outcome can reliably be predicted.

Chou KL, Forman MS, Trojanowski JQ, Hurtig HI, Baltuch GH. · Parkinson's Disease and Movement Disorders Center and Department of Neurosurgery, Penn Neurological Institute at Pennsylvania Hospital, Philadelphia, Pennsylvania 19107, USA. · J Neurosurg. · Pubmed #15035294 No free full text.

Abstract: The authors report the clinicopathological findings in a patient in whom levodopa-responsive parkinsonism developed at 45 years of age. The patient experienced asymmetrical onset of symptoms, sustained benefit from levodopa, and motor fluctuations and dyskinesias, but there were no prominent autonomic, cerebellar, or pyramidal signs. He was diagnosed clinically with Parkinson disease (PD) and underwent bilateral subthalamic nucleus deep brain stimulation (DBS) surgery 9 years after symptom onset. He did not respond to stimulation or medication postoperatively, however, and died 12 weeks after surgery of repeated aspiration pneumonias. Postmortem examination revealed neuron loss in the substantia nigra and basal ganglia, and numerous alpha-synuclein-positive glial cytoplasmic inclusions in the subcortical nuclei, cerebellum, and brainstem, findings that established a neuropathological diagnosis of multiple system atrophy (MSA). Furthermore, there was an atypical and robust inflammatory reaction, as well as numerous glial cytoplasmic inclusions surrounding both DBS electrode termination sites. The authors speculate that the presence of alpha-synuclein in the striatum, combined with the inflammation surrounding the electrodes, contributed to the ineffectiveness of stimulation and dopaminergic medications postoperatively. This case demonstrates the ineffectiveness of DBS in MSA, even when the patient is responsive to levodopa, and emphasizes the need for diagnostic modalities that can be used to distinguish PD from MSA and other parkinsonian syndromes in which the levodopa response pattern is typical of PD.

Lee C, Grossman M, Morris J, Stern MB, Hurtig HI. · Department of Neurology, Hospital of the University of Pennsylvania, 3 Gates Center, 3400 Spruce Street, Philadelphia, PA 19104-4283, USA. · Brain Lang. · Pubmed #12744946 No free full text.

Abstract: Several studies have suggested that patients with Parkinson's disease (PD) have sentence comprehension difficulty in part because of their limited executive resources. However, these assessments confound the executive resources contributing to sentence comprehension with the resources needed for task performance. In the present study, we used a word detection technique that minimizes task demands in order to evaluate attentional and processing speed resources during the comprehension of simple sentences without subordinate clauses and sentences containing subject-relative and object-relative center-embedded subordinate clauses. We found that PD patients have poor sensitivity to phonetic errors embedded in unbound grammatical morphemes, regardless of the clausal structure of the sentence, suggesting difficulty attending to grammatical morphemes. We also found that PD patients are significantly slowed in their sensitivity to phonetic errors in content words embedded in object-relative center-embedded sentences. Slowed sensitivity to content words in object-relative sentences was correlated with timed executive measures of planning. On a traditional measure of comprehension, these PD patients were impaired for sentences containing object-relative center-embedded clauses compared to sentences with subject-relative center-embedded clauses, and comprehension of object-relative sentences was correlated with executive measures. Our findings are consistent with the claim that limited executive resources for strategic attention and processing speed contribute to the sentence comprehension difficulties of PD patients.

Grossman M, Lee C, Morris J, Stern MB, Hurtig HI. · Department of Neurology, University of Pennsylvania, Philadelphia, USA. · Brain Lang. · Pubmed #11896660 No free full text.

Abstract: Patients with Parkinson's disease (PD) have sentence comprehension difficulty, but it is unclear whether this is due to a deficit in grammatical processing or to an executive resource limitation. To assess grammatical processing in PD while minimizing task-related demands, PD patients and healthy control subjects performed a word detection procedure that assesses sensitivity to grammatical agreements in sentences in an "on-line" fashion. With this technique, we found that control subjects and PD patients are equally sensitive to grammatical agreement violations in sentences. A traditional, resource-demanding measure of sentence comprehension was also administered to the same PD patients. In comparison to healthy controls, PD patients were significantly impaired in their relative comprehension of sentences containing object-gap subordinate clauses compared to subject-gap subordinate clauses. Performance on several executive resource measures was also impaired in PD, and this correlated with their comprehension performance. Sensitivity to grammatical agreements with the word detection procedure, in the context of sentence comprehension difficulty on a traditional measure, suggests that PD patients' executive resource limitations contribute to their sentence comprehension difficulty.

Grossman M, Glosser G, Kalmanson J, Morris J, Stern MB, Hurtig HI. · Department of Neurology, University of Pennsylvania Medical Center, Philadelphia, PA, USA. · J Neurol Sci. · Pubmed #11239945 No free full text.

Abstract: OBJECTIVE: To determine the role of dopamine in the executive resource component of sentence comprehension. METHODS: We studied sentence-picture matching in 20 right-handed, non-demented, native English speakers with mild Parkinson's disease (PD) when 'on' and 'off' their levodopa, taking into account disease duration to control for endogenous dopamine metabolism. We also administered a verbal working memory measure that does not involve specific grammatical manipulations. RESULTS: PD patients 'off' levodopa demonstrated a significant discrepancy in their comprehension of grammatically complex sentences compared to grammatically simpler sentences that was not evident when PD patients were 'on' levodopa. An error analysis demonstrated that impaired comprehension of grammatically complex sentences when 'off' levodopa was associated with poorer performance on foils requiring working memory resources. Performance on an independent measure of verbal working memory correlated only with comprehension of grammatically complex sentences during levodopa supplementation, but working memory according to this measure did not differ during 'on' and 'off' states. CONCLUSION: Dopamine supports the executive resources contributing to sentence comprehension in PD.

Giasson BI, Duda JE, Murray IV, Chen Q, Souza JM, Hurtig HI, Ischiropoulos H, Trojanowski JQ, Lee VM. · Center for Neurodegenerative Disease Research and Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA. · Science. · Pubmed #11062131 links to  free full text

Abstract: Aggregated alpha-synuclein proteins form brain lesions that are hallmarks of neurodegenerative synucleinopathies, and oxidative stress has been implicated in the pathogenesis of some of these disorders. Using antibodies to specific nitrated tyrosine residues in alpha-synuclein, we demonstrate extensive and widespread accumulations of nitrated alpha-synuclein in the signature inclusions of Parkinson's disease, dementia with Lewy bodies, the Lewy body variant of Alzheimer's disease, and multiple system atrophy brains. We also show that nitrated alpha-synuclein is present in the major filamentous building blocks of these inclusions, as well as in the insoluble fractions of affected brain regions of synucleinopathies. The selective and specific nitration of alpha-synuclein in these disorders provides evidence to directly link oxidative and nitrative damage to the onset and progression of neurodegenerative synucleinopathies.

Grossman M, Kalmanson J, Bernhardt N, Morris J, Stern MB, Hurtig HI. · Department of Neurology, University of Pennsylvania Medical Center, Philadelphia 19104-4283, USA. · Brain Lang. · Pubmed #10872635 No free full text.

Abstract: Patients with idiopathic Parkinson's disease (PD) were asked to identify the agent of the action in orally presented sentences with subject-relative or object-relative center-embedded clauses while simultaneously performing a secondary task that was less resource-demanding (finger tapping) or more resource-demanding (recognition span). We found that a subgroup of PD patients with impaired sentence comprehension at baseline (no secondary task) did not differ from random in their accuracy understanding all types of sentences during the more demanding (recognition span) condition and also had difficulty understanding the most complex sentences during the less demanding (finger tapping) condition. Control subjects and PD patients without baseline sentence comprehension difficulty were random only in their comprehension of the most complex sentences under the more demanding (recognition span) secondary task condition. Examination of response latencies for accurately understood sentences revealed only an effect for the type of sentence, and this was equally evident across all groups of subjects and regardless of the condition under which the sentences were administered. The sensitivity of PD patients' sentence comprehension accuracy to secondary task resource demands is most consistent with the hypothesis that limited cognitive resources contribute to sentence comprehension difficulty in PD.

Hurtig HI, Trojanowski JQ, Galvin J, Ewbank D, Schmidt ML, Lee VM, Clark CM, Glosser G, Stern MB, Gollomp SM, Arnold SE. · Department of Neurology, University of Pennsylvania, PA, USA. · Neurology. · Pubmed #10822429 No free full text.

Abstract: BACKGROUND: Dementia is a frequent complication of idiopathic parkinsonism or PD, usually occurring later in the protracted course of the illness. The primary site of neuropathologic change in PD is the substantia nigra, but the neuropathologic and molecular basis of dementia in PD is less clear. Although Alzheimer's pathology has been a frequent finding, recent advances in immunostaining of alpha-synuclein have suggested the possible importance of cortical Lewy bodies (CLBs) in the brains of demented patients with PD. METHODS: The brains of 22 demented and 20 nondemented patients with a clinical and neuropathologic diagnosis of PD were evaluated with standard neuropathologic techniques. In addition, CLBs and dystrophic neurites were identified immunohistochemically with antibodies specific for alpha-synuclein and ubiquitin; plaques and tangles were identified by staining with thioflavine S. Associations between dementia status and pathologic markers were tested with logistic regression. RESULTS: CLBs positive for alpha-synuclein are highly sensitive (91%) and specific (90%) neuropathologic markers of dementia in PD and slightly more sensitive than ubiquitin-positive CLBs. They are better indicators of dementia than neurofibrillary tangles, amyloid plaques, or dystrophic neurites. CONCLUSION: CLBs detected by alpha-synuclein antibodies in patients with PD are a more sensitive and specific correlate of dementia than the presence of Alzheimer's pathology, which was present in a minority of the cases in this series.