Comparison of sporadic and familial behavioral variant frontotemporal dementia (FTD) in a North American cohort.

INTRODUCTION: Behavioral variant frontotemporal dementia (bvFTD) may present sporadically or due to an autosomal dominant mutation. Characterization of both forms will improve understanding of the generalizability of assessments and treatments. METHODS: A total of 135 sporadic (s-bvFTD; mean age 63.3 years; 34% female) and 99 familial (f-bvFTD; mean age 59.9; 48% female) bvFTD participants were identified. f-bvFTD cases included 43 with known or presumed chromosome 9 open reading frame 72 (C9orf72) gene expansions, 28 with known or presumed microtubule-associated protein tau (MAPT) mutations, 14 with known progranulin (GRN) mutations, and 14 with a strong family history of FTD but no identified mutation. RESULTS: Participants with f-bvFTD were younger and had earlier age at onset. s-bvFTD had higher total Neuropsychiatric Inventory Questionnaire (NPI-Q) scores due to more frequent endorsement of depression and irritability. DISCUSSION: f-bvFTD and s-bvFTD cases are clinically similar, suggesting the generalizability of novel biomarkers, therapies, and clinical tools developed in either form to the other.

Active lifestyles moderate clinical outcomes in autosomal dominant frontotemporal degeneration.

INTRODUCTION: Leisure activities impact brain aging and may be prevention targets. We characterized how physical and cognitive activities relate to brain health for the first time in autosomal dominant frontotemporal lobar degeneration (FTLD). METHODS: A total of 105 mutation carriers (C9orf72/MAPT/GRN) and 69 non-carriers reported current physical and cognitive activities at baseline, and completed longitudinal neurobehavioral assessments and brain magnetic resonance imaging (MRI) scans. RESULTS: Greater physical and cognitive activities were each associated with an estimated >55% slower clinical decline per year among dominant gene carriers. There was also an interaction between leisure activities and frontotemporal atrophy on cognition in mutation carriers. High-activity carriers with frontotemporal atrophy (-1 standard deviation/year) demonstrated >two-fold better cognitive performances per year compared to their less active peers with comparable atrophy rates. DISCUSSION: Active lifestyles were associated with less functional decline and moderated brain-to-behavior relationships longitudinally. More active carriers "outperformed" brain volume, commensurate with a cognitive reserve hypothesis. Lifestyle may confer clinical resilience, even in autosomal dominant FTLD.

Mild cognitive impairment in Parkinson's disease.

Parkinson's disease (PD) traditionally has been defined by its characteristic motor hallmarks, but non-motor features such as cognitive impairment and dementia are increasingly recognized as part of PD. Mild cognitive impairment (MCI) is common in non-demented PD patients, occurring in about 20-50%. Frequency estimates and clinical features of mild cognitive impairment in PD (PD-MCI), however, vary across studies due to methodological differences and lack of uniform diagnostic criteria for PD-MCI. Overall, PD-MCI patients exhibit nonamnestic deficits in cognitive domains such as executive function, attention, and visuospatial function; however, the cognitive phenotype of PD-MCI is heterogeneous with some patients demonstrating greater amnestic deficits. PD-MCI patients, particularly those with posterior cortical profiles, may be at high risk for developing dementia. Various biomarkers studied in PD-MCI including cerebrospinal fluid, genetic analyses, and neuroimaging suggest that there may be distinct PD-MCI profiles. Future studies using uniform PD-MCI diagnostic criteria and incorporating biomarkers and longitudinal follow-up of PD-MCI cohorts are needed to understand PD-MCI as a transitional state between normal cognition and dementia.

Tauopathies with parkinsonism: clinical spectrum, neuropathologic basis, biological markers, and treatment options.

Tauopathies with parkinsonism represent a spectrum of disease entities unified by the pathologic accumulation of hyperphosphorylated tau protein fragments within the central nervous system. These pathologic characteristics suggest shared pathogenetic pathways and possible molecular targets for disease-modifying therapeutic interventions. Natural history studies, for instance, in progressive supranuclear palsy, frontotemporal dementia with parkinsonism linked to chromosome 17, corticobasal degeneration, and Niemann-Pick disease type C as well as in amyotrophic lateral sclerosis/Parkinson-dementia complex permit clinical characterization of the disease phenotypes and are crucial to the development and validation of biological markers for differential diagnostics and disease monitoring, for example, by use of neuroimaging or proteomic approaches. The wide pathologic and clinical spectrum of the tauopathies with parkinsonism is reviewed in this article, and perspectives on future advances in the understanding of the pathogenesis are given, together with potential therapeutic strategies.

Bilateral subthalamotomy in Parkinson's disease: initial and long-term response.

We conducted an open label pilot study of the effect of bilateral subthalamotomy in 18 patients with advanced Parkinson's disease. In seven patients, the first subthalamotomy pre-dated the second by 12-24 months ('staged surgery'). Subsequently, a second group of 11 patients received bilateral subthalamotomy on the same day ('simultaneous surgery'). Patients were assessed according to the CAPIT (Core Assessment Program for Intracerebral Transplantation) protocol, a battery of timed motor tests and neuropsychological tests. Evaluations were performed in the 'off' and 'on' drug states before surgery and at 1 and 6 months and every year thereafter for a minimum of 3 years after bilateral subthalamotomy. Compared with baseline, bilateral subthalamotomy induced a significant (P < 0.001) reduction in the 'off' (49.5%) and 'on' (35.5%) Unified Parkinson's Disease Rating Scale (UPDRS) motor scores at the last assessment. A blind rating of videotape motor exams in the 'off' and 'on' medication states preoperatively and at 2 years postoperatively also revealed a significant improvement. All of the cardinal features of Parkinson's disease as well as activities of daily living (ADL) scores significantly improved (P < 0.01). Levodopa-induced dyskinesias were reduced by 50% (P < 0.01), and the mean daily levodopa dose was reduced by 47% at the time of the last evaluation compared with baseline (P < 0.0001). Dyskinesias occurred intraoperatively or in the immediate postoperative hours in 13 patients, but were generally mild and short lasting. Three patients developed severe generalized chorea that gradually resolved within the next 3-6 months. Three patients experienced severe and persistent postoperative dysarthria. In two, this coincided with the patients exhibiting large bilateral lesions also suffering from severe dyskinesias. No patient exhibited permanent cognitive impairment. The motor benefit has persisted for a follow-up of 3-6 years. This study indicates that bilateral subthalamotomy may induce a significant and long-lasting improvement of advanced Parkinson's disease, but the clinical outcome was variable. This variability may depend in large part on the precise location and volume of the lesions. Further refinement of the surgical procedure is mandatory.

Swallowing disturbances in the corticobasal syndrome.

OBJECTIVES: To determine the characteristics of swallowing and speech disturbances in patients with corticobasal syndrome (CBS) compared to healthy controls, and whether a subjective swallowing questionnaire, the NIH-Speech Pathology swallowing questionnaire (NIH-SQ), can predict swallowing impairment. METHODS: Twenty-four consecutive CBS patients underwent a swallowing assessment comprised of the NIH-SQ, ultrasound swallow study (US) and modified barium swallow (MBS) study. Healthy controls (n = 28) completed the NIH-SQ and the US. RESULTS: Ninety-six percent of the patients with CBS reported at least one complaint in the NIH-SQ, 59% had abnormal dry swallow duration and 10% abnormal wet swallow duration. Twenty-three patients with CBS had some abnormality on the MBS. The MBS category "piecemeal deglutition" (excessive lingual gestures causing multiple swallows required to clear a single bolus) was characteristic of CBS patients. No aspiration was detected. No NIH-SQ cutoff score or combination of subjective complaints predicted an abnormal MBS. Fifty-two percent of the patients had speech apraxia. CONCLUSIONS: Swallowing and speech disturbances are common in patients with CBS and differ from those previously reported in patients with PSP syndrome. Piecemeal deglutition and speech apraxia are characteristic features of our CBS patients. Although the NIH-SQ cannot predict the results of the more objective MBS in this population, it characterizes the patients' major subjective swallowing complaints.

Office of Rare Diseases neuropathologic criteria for corticobasal degeneration.

A working group supported by the Office of Rare Diseases of the National Institutes of Health formulated neuropathologic criteria for corticobasal degeneration (CBD) that were subsequently validated by an independent group of neuropathologists. The criteria do not require a specific clinical phenotype, since CBD can have diverse clinical presentations, such as progressive asymmetrical rigidity and apraxia, progressive aphasia, or frontal lobe dementia. Cortical atrophy, ballooned neurons, and degeneration of the substantia nigra have been emphasized in previous descriptions and are present in CBD, but the present criteria emphasize tau-immunoreactive lesions in neurons, glia, and cell processes in the neuropathologic diagnosis of CBD. The minimal pathologic features for CBD are cortical and striatal tau-positive neuronal and glial lesions, especially astrocytic plaques and thread-like lesions in both white matter and gray matter, along with neuronal loss in focal cortical regions and in the substantia nigra. The methods required to make this diagnosis include histologic stains to assess neuronal loss, spongiosis and ballooned neurons, and a method to detect tau-positive neuronal and glial lesions. Use of either the Gallyas silver staining method or immunostains with sensitive tau antibodies is acceptable. In cases where ballooned neurons are sparse or difficult to detect, immunostaining for phospho-neurofilament or alpha-B-crystallin may prove helpful. Methods to assess Alzheimer-type pathology and Lewy body pathology are necessary to rule out other causes of dementia and Parkinsonism. Using these criteria provides good differentiation of CBD from other tauopathies, except frontotemporal dementia and Parkinsonism linked to chromosome 17, where additional clinical or molecular genetic information is required to make an accurate diagnosis.

Validity and reliability of the preliminary NINDS neuropathologic criteria for progressive supranuclear palsy and related disorders.

We investigated the validity and reliability of diagnoses made by eight neuropathologists who used the preliminary NINDS neuropathologic diagnostic criteria for progressive supranuclear palsy (PSP) and related disorders. The specific disorders were typical, atypical, and combined PSP, postencephalitic parkinsonism, corticobasal ganglionic degeneration, and Pick's disease. These disorders were chosen because of the difficulties in their neuropathologic differentiation. We assessed validity by measuring sensitivity and positive predictive value. Reliability was evaluated by measuring pairwise and group agreement. From a total of 62 histologic cases, each neuropathologist independently classified 16 to 19 cases for the pairwise analysis and 5 to 6 cases for the group analysis. The neuropathologists were unaware of the study design, unfamiliar with the assigned cases, and initially had no clinical information about the cases. Our results showed that with routine sampling and staining methods, neuropathologic examination alone was not fully adequate for differentiating the disorders. The main difficulties were discriminating the subtypes of PSP and separating postencephalitic parkinsonism from PSP. Corticobasal ganglionic degeneration and Pick's disease were less difficult to distinguish from PSP. The addition of minimal clinical information contributed to the accuracy of the diagnosis. On the basis of results obtained, we propose clinicopathologic diagnostic criteria to improve on the NINDS criteria.

Effects of physostigmine on spatial attention in patients with progressive supranuclear palsy.

We tested patients with progressive supranuclear palsy and control subjects on a task of visuopatial attention. Targets preceded by cues on the same side were termed validly cued; and those on the opposite side, invalidly cued. For all subjects, validly cued targets were responded to faster than those that were invalidly cued. The difference between reaction times for invalidly and validly cued targets, which is hypothesized to measure attentional movement, was significantly increased for the patients. The performance of the controls on certain neuropsychological tests was correlated with their attentional ability. These correlations were altered by progressive supranuclear palsy. Physostigmine treatment of the patients induced a speeding of responses to invalidly cued targets as a function of the duration of the disease. These studies show defects in cognition and attention in patients with progressive supranuclear palsy and demonstrate that physostigmine reduces some of the abnormal visual attentional performance.

Slowed information processing in multiple sclerosis.

Sixteen patients with a definitive diagnosis of multiple sclerosis (MS) and an equal number of matched controls were administered tests of memory and information processing speed. Results indicated a significant long-term verbal memory impairment in patients with MS, with spared short-term memory and memory scanning. Speed of information processing was evaluated with the Paced Auditory Serial Addition Test. The results for the two highest rates of presentation revealed significantly impaired processing in the MS group. Performance at the higher rates and retrieval of information from long-term memory were significantly correlated. These results suggest that slowed information processing is a deficit that contributes to long-term memory impairment in patients with MS.

Frontal lobe function in progressive supranuclear palsy.

Performance on tasks evaluating "executive and attentional" processes presumably subserved by prefrontal cortex were compared in patients with progressive supranuclear palsy and with age- and education-matched control subjects. The results indicated that patients with progressive supranuclear palsy were particularly impaired when a task required sequential movements, conceptual shifting, monitoring the frequency with which stimuli are presented, or rapid retrieval of verbal knowledge. These deficits could not simply be accounted for by slowed information processing or by a deficit in representational knowledge. Conceivably, "weak activation" of frontal lobe representational knowledge characterized by an observed attentional deficit results in the neuropsychological impairments noted in patients with progressive supranuclear palsy. The oral administration of physostigmine, under double-blind placebo-controlled conditions, did not facilitate executive or attentional performance as evaluated by our tasks.

Memory impairment in patients with progressive supranuclear palsy.

Verbal memory was compared in 12 patients with progressive supranuclear palsy and 12 healthy control subjects matched for age, sex, and education. Learning, consolidation, and retrieval were significantly impaired in patients with progressive supranuclear palsy. Information scanning, which requires the use of short-term memory processes, remained intact. Duration of symptoms and degree of motor dysfunction correlated with intrusions during learning. No relation between central dopamine metabolism and memory dysfunction could be established.

Neuropsychiatric assessment of patients with hyperkinetic and hypokinetic movement disorders.

BACKGROUND: The role of the basal ganglia in neuropsychiatric behaviors is not well known. Anatomical, neurophysiological, and neurochemical evidence supports the notion of parallel direct and indirect basal ganglia thalamocortical motor systems, the differential involvement of which accounts for the hypokinesia or hyperkinesia observed in basal ganglia disorders. OBJECTIVES: To evaluate the neuropsychiatric manifestations of patients with a hyperkinetic movement disorder, such as Huntington disease (HD), vs a hypokinetic disease, such as progressive supranuclear palsy (PSP). To verify if patients with HD show a greater frequency of hyperactive behaviors (eg, agitation, irritation, euphoria, or anxiety), while those with PSP exhibit hypoactive behaviors (eg, apathy). PATIENTS AND METHODS: The Neuropsychiatric Inventory, a tool with established validity and reliability, was administered to 29 patients with HD (mean +/- SD age, 43.8 +/- 2 years) and 34 with PSP (mean +/- SD age, 66.6 +/- 1.2 years), matched for education, symptom duration, and overall degree of dementia. RESULTS: There was no difference between the groups in the total Neuropsychiatric Inventory scores. However, there was a double dissociation in behaviors: patients with HD exhibited significantly more agitation (45%), irritability (38%), and anxiety (34%), whereas patients with PSP exhibited more apathy (82%) (P < .01). Euphoria was present only in patients with HD. CONCLUSIONS: We found that patients with HD manifested predominantly hyperactive behaviors, while those with PSP manifested hypoactive behaviors. Based on our findings and the anatomical lesions known to occur in these disorders, we suggest that the hyperactive behaviors in HD are secondary to an excitatory subcortical output through the medial and orbitofrontal cortical circuits, while in PSP the hypoactive behaviors are secondary to hypostimulation.

Pharmacological therapy in progressive supranuclear palsy.

BACKGROUND: To our knowledge, previous reports on drug treatment in progressive supranuclear palsy have not evaluated autopsy-confirmed cases. OBJECTIVE: To evaluate pharmacological treatment responses from detailed clinical records in patients with autopsy-confirmed progressive supranuclear palsy. SUBJECTS AND METHODS: We reviewed medical records for clinical presentation and pharmacological response in 12 patients with autopsy-confirmed progressive supranuclear palsy diagnosed using the National Institute of Neurological Disorders and Stroke pathologic criteria. For each drug class, exposure, global positive response, and specific positive response (parkinsonism, other movement disorders, or gaze dysfunction) were recorded. RESULTS: Drug classes examined were dopaminergics (all patients), tricyclics (3 patients), methysergide maleate (3 patients), 5-hydroxytryptophan (2 patients), and anticholinergics and selective serotonin inhibitors (1 patient). Positive clinical response was detected in 7 of the patients receiving dopaminergic drugs and in 1 patient each receiving tricyclics, methysergide, and 5-hydroxytryptophan, respectively. None of the patients responded markedly however, and there was no persistent beneficial effect. Use of dopaminergic drugs most frequently improved parkinsonian features, but disabling adverse effects included orthostatic hypotension (6 patients), hallucinations and delusions (3 patients), gastrointestinal complaints (3 patients), and dizziness (1 patient). Only 1 patient developed dyskinesia. CONCLUSION: Use of antiparkinsonian medications and other neurotransmitter replacement therapies was largely ineffective and caused frequent adverse effects in this series of patients with autopsy-confirmed with progressive supranuclear palsy.

Multiple memory deficits in patients with multiple sclerosis. Exploring the working memory system.

Some patients with multiple sclerosis (MS) demonstrate impaired memory. A group of 16 patients with MS who were mildly to moderately affected (Kurtzke Expanded Disability Status Scale Score = 3.8) were studied, and they were compared with a matched control group on tests of "working memory." The working memory system was explored by evaluating the amount of information that can temporarily be held in a buffer system during encoding. Results indicated that patients with MS have difficulty in processing information at the level of a hypothesized articulatory loop in working memory. This deficit was correlated with their retrieval of verbal information from long-term memory, as well as how accurately they processed verbal information presented at a rapid rate. There was no significant relationship between ratings of MS severity or number of plaques visualized on magnetic resonance imaging scans and the degree of working memory deficit.

Progression of dysarthria and dysphagia in postmortem-confirmed parkinsonian disorders.

BACKGROUND: Dysarthria and dysphagia are known to occur in parkinsonian syndromes such as Parkinson disease (PD), dementia with Lewy bodies (DLB), corticobasal degeneration (CBD), multiple system atrophy (MSA), and progressive supranuclear palsy (PSP). Differences in the evolution of these symptoms have not been studied systematically in postmortem-confirmed cases. OBJECTIVE: To study differences in the evolution of dysarthria and dysphagia in postmortem-confirmed parkinsonian disorders. PATIENTS AND METHODS: Eighty-three pathologically confirmed cases (PD, n = 17; MSA, n = 15; DLB, n = 14; PSP, n = 24; and CBD, n = 13) formed the basis for a multicenter clinicopathological study organized by the National Institute of Neurological Disorders and Stroke, Bethesda, Md. Cases with enough clinicopathological documentation for the purpose of the study were selected from research and neuropathological files of 7 medical centers in 4 countries (Austria, France, England, and the United States). RESULTS: Median dysarthria latencies were short in PSP and MSA (24 months each), intermediate in CBD and DLB (40 and 42 months), and long in PD (84 months). Median dysphagia latencies were intermediate in PSP (42 months), DLB (43 months), CBD (64 months), and MSA (67 months), and long in PD (130 months). Dysarthria or dysphagia within 1 year of disease onset was a distinguishing feature for atypical parkinsonian disorders (APDs) (specificity, 100%) but failed to further distinguish among the APDs. Survival time after onset of a complaint of dysphagia was similar in PD, MSA, and PSP (15 to 24 months, P =.7) and latency to a complaint of dysphagia was highly correlated with total survival time (rho = 0.88; P<.001) in all disorders. CONCLUSIONS: Latency to onset of dysarthria and dysphagia clearly differentiated PD from the APDs, but did not help distinguish different APDs. Survival after onset of dysphagia was similarly poor among all parkinsonian disorders. Evaluation and adequate treatment of patients with PD who complain of dysphagia might prevent or delay complications such as aspiration pneumonia, which in turn may improve quality of life and increase survival time.

What is the accuracy of the clinical diagnosis of multiple system atrophy? A clinicopathologic study.

BACKGROUND: The presentation of symptoms for multiple system atrophy (MSA) varies. Because there are no specific markers for its clinical diagnosis, the diagnosis rests on the results of the neuropathologic examination. Despite several clinicopathologic studies, the diagnostic accuracy for MSA is unknown. OBJECTIVES: To determine the accuracy for the clinical diagnosis of MSA and to identify, as early as possible, those features that would best predict MSA. DESIGN: One hundred five autopsy-confirmed cases of MSA and related disorders (MSA [n=16], non-MSA [n=89]) were presented as clinical vignettes to 6 neurologists (raters) who were unaware of the study design. Raters identified the main clinical features and provided a diagnosis based on descriptions of the patients' first and last clinic visits. METHODS: Interrater reliability was evaluated with the use of kappa statistics. Raters' diagnoses and those of the primary neurologists (who followed up the patients) were compared with the autopsy-confirmed diagnoses to estimate the sensitivity and positive predictive values at the patients' first and last visits. Logistic regression analysis was used to determine the best predictors to diagnose MSA. RESULTS: For the first visit (median, 42 months after the onset of symptoms), the raters' sensitivity (median, 56%; range, 50%-69%) and positive predictive values (median, 76%; range, 61%-91%) for the clinical diagnosis of MSA were not optimal. For the last visit (74 months after the onset of symptoms), the raters' sensitivity (median, 69%; range, 56%-94%) and positive predictive values (median, 80%; range, 77%-92%) improved. Primary neurologists correctly identified 25% and 50% of the patients with MSA at the first and last visits, respectively. False-negative and -positive misdiagnoses frequently occurred in patients with Parkinson disease and progressive supranuclear palsy. Early severe autonomic failure, absence of cognitive impairment, early cerebellar symptoms, and early gait disturbances were identified as the best predictive features to diagnose MSA. CONCLUSIONS: The low sensitivity for the clinical diagnosis of MSA, particularly among neurologists who followed up these patients in the tertiary centers, suggests that this disorder is underdiagnosed. The misdiagnosis of MSA is usually due to its confusion with Parkinson disease or progressive supranuclear palsy, thus compromising the research on all 3 disorders.

Accuracy of the clinical diagnoses of Lewy body disease, Parkinson disease, and dementia with Lewy bodies: a clinicopathologic study.

BACKGROUND: Whether Parkinson disease (PD) and dementia with Lewy bodies (DLB) represent 2 distinct nosologic entities or are diverse phenotypes of Lewy body disease is subject to debate. OBJECTIVES: To determine the accuracy of the diagnoses of Lewy body disease, PD, and DLB by validating the clinical diagnoses of 6 neurologists with the neuropathologic findings and to identify early predictors of the diagnoses. METHODS: Six raters who were unaware of the neuropathologic diagnoses analyzed 105 clinical vignettes corresponding to 29 cases of Lewy body disease (post hoc analysis of 15 patients with PD and 14 with DLB) and 76 patients without PD or DLB whose cases were confirmed through autopsy findings. MAIN OUTCOME MEASURES: Sensitivity and positive predictive value (PPV) were chosen as validity measures and the K statistic as a reliability measure. RESULTS: Interrater reliability for the diagnoses of Lewy body disease and PD was moderate for the first visit and substantial for the last, whereas agreement for diagnosis of DLB was fair for the first visit and slight for the last. Median sensitivity for diagnosis of Lewy body disease was 56.9% for the first visit and 67.2% for the last; median PPV was 60.0% and 77.4%, respectively. Median sensitivity for the diagnosis of PD was 73.3% for the first visit and 80.0% for the last; median PPV was 45.9% and 64.1%, respectively. Median sensitivity for the diagnosis of DLB was 17.8% for the first visit and 28.6% for the last; median PPV was 75.0% for the first visit and 55.8% for the last. The raters' results were similar to those of the primary neurologists. Several features differentiated PD from DLB, predicted each disorder, and could be used as clinical pointers. CONCLUSIONS: The low PPV with relatively high sensitivity for the diagnosis of PD suggests overdiagnosis. Conversely, the extremely low sensitivity for the diagnosis of DLB suggests underdiagnosis. Although the case mix included in the study may not reflect the frequency of these disorders in practice, limiting the clinical applicability of the validity measures, the raters' results were similar to those of the primary neurologists who were not exposed to such limitations. Overall, our study confirms features suggested to predict these disorders, except for the early presence of postural imbalance, which is not indicative of either disorder.

Therapy and management of frontal lobe dementia patients.

Patients with frontal lobe dementia (FLD) include those who suffer from Pick's disease, corticobasal degeneration, FLD without specific histopathologic features, as well as the infrequent families with frontotemporal dementia and parkinsonism associated with chromosome 17. Currently there have been no systematic efforts to manage and to treat patients with FLD. Drawing on the accumulated experience of clinicians and the known therapeutic approaches for patients with other neurodegenerative disorders such as AD and PD, the author discusses possible neurotransmitter replacement and biologic therapeutic approaches for patients with FLD.

Tau genotype: no effect on onset, symptom severity, or survival in progressive supranuclear palsy.

Genetic studies have shown that progressive supranuclear palsy (PSP) is associated with inheritance of a specific genotype (H1/H1) in the tau gene. The authors investigated whether the H1/H1 genotype or A0/A0 genotype independently or in conjunction with selected environmental risk factors influences the age at onset, severity, or survival in patients with PSP. Our findings suggest that tau genotyping does not predict the prognosis of PSP.