Antibodies against Periodontal Microorganisms and Cognition in Older Adults.

INTRODUCTION: Markers of poor oral health are associated with impaired cognition and higher risk of Alzheimer disease (AD) and thus may help predict AD. OBJECTIVES: The aim of this study was to evaluate the cross-sectional association between empirically derived groups of 19 IgG antibodies against periodontal microorganisms and cognition in middle-aged and older adults. METHODS: The study population consisted of participants of the third National Health and Nutrition Examination Survey (NHANES III) (1988 to 1994), who were 60 y and older, among whom cognition and IgG antibodies against 19 periodontal microorganisms were measured (N = 5,162). RESULTS: In multivariable quantile regression analyses, the Orange-Red (Prevotella melaninogenica, Prevotella intermedia, Prevotella nigrescens, Porphyromonas gingivalis) and Yellow-Orange (Staphylococcus intermedius, Streptococcus oralis, Streptococcus mutans, Fusobacterium nucleatum, Peptostreptococcus micros, Capnocytophaga ochracea) cluster scores were negatively associated with cognition. A 1-unit higher cluster score for the Orange-Red cluster was associated on average with a lower cognitive score (ß for 30th quantile = -0.2640; 95% confidence interval [CI], -0.3431 to -0.1848). Similarly, a 1-unit higher score for the Yellow-Orange cluster was associated with a lower cognitive score (ß for 30th quantile = -0.2445; 95% CI, -0.3517 to -0.1372). CONCLUSION: Groups of IgG antibodies against periodontal microorganisms were associated with lower cognition among free living adults 60 years and older, who were previously undiagnosed with cognitive impairment. Though poor oral health precedes the development of dementia and AD, oral health information is currently not used, to our knowledge, to predict dementia or AD risk. Combining our findings with current algorithms may improve risk prediction for dementia and AD. KNOWLEDGE TRANSLATION STATEMENT: IgG antibodies against periodontal microorganisms were associated with lower cognition among adults 60 years and older previously undiagnosed with cognitive impairment. Periodontal disease may predict cognition among older adults.

Dietary Inflammatory Index, Pre-Frailty and Frailty among Older US Adults: Evidence from the National Health and Nutrition Examination Survey, 2007-2014.

OBJECTIVE: This study aimed to investigate the association between dietary inflammation, pre-frailty and frailty among older US adults. Additionally, effect modification of gender on the association between dietary inflammation and frailty was assessed. DESIGN: Study data came from the National Health and Nutrition Examination Survey (2007-2014) - a nationally representative, cross-sectional study of adults. PARTICIPANTS: The analytic sample included adults ≥60 years (n=7,182). MEASUREMENTS: Dietary Inflammatory Index (DII®) scores were calculated from 24-hour dietary recalls; DII was categorized into quintiles from Quintile 1 (Q1) (least inflammatory) to Q5 (most inflammatory). Frailty was assessed by four criteria: exhaustion, weakness, low body mass, and low physical activity. Individuals were then categorized into robust (0 criteria), pre-frail (1-2 criteria), or frail (3-4 criteria). Multinomial logistic regression was used to examine the odds of frailty categories (pre-frail vs. robust; frail vs. robust). RESULTS: After adjusting for potential confounders, individuals in DII quintile 5 (vs Q1) were more likely to be pre-frail (OR = 1.71; 95% CI: 1.36-2.15) and frail (OR = 1.70; 95% CI: 1.02-2.85). Individuals in Q4 had greater odds of frailty only (OR = 1.82; 95% CI: 1.13, 2.93). No evidence of effect modification by gender on the association of DII and frailty was found. CONCLUSION: This study expands upon previous evidence of a relationship between dietary inflammation and frailty. When designing nutrition-based frailty interventions, inflammatory properties of diets should be considered.

Association of Obesity and Frailty in Older Adults: NHANES 1999-2004.

OBJECTIVES: Body composition changes with aging can increase rates of obesity, frailty and impact function. Measuring adiposity using body fat (%BF) or central adiposity using waist circumference (WC) have greater diagnostic accuracy than traditional measures such as body mass index (BMI). DESIGN: This is an observational study. SETTING: This study focused on older community-dwelling participants. PARTICIPANTS: We identified individuals age ≥ 60 years old using the 1999-2004 cross-sectional National Health and Nutrition Survey (NHANES). INTERVENTION: The primary analysis evaluated the association between frailty and %BF or WC. Frailty was the primary predictor (robust=referent) and %BF and WC were considered continuous outcomes. Multiple imputation analyses accounted for missing characteristics. MEASUREMENT: Dual energy x-ray absorptiometry was used to assess %BF and WC was objectively measured. Frailty was defined using an adapted version of Fried's criteria that was self-reported: (low BMI<18.5kg/m2; slow walking speed [<0.8m/s]; weakness [unable to lift 10lbs]; exhaustion [difficulty walking between rooms on same floor] and low physical activity [compared to others]). Robust, pre-frail and frail persons met zero, 1 or 2, and ≥3 criteria, respectively. RESULTS: Of the 4,984 participants, the mean age was 71.1±0.2 (SE) years and 56.5% were females. We classified 2,246 (50.4%), 2,195 (40.3%), and 541 (9.2%) individuals as robust, pre-frail and frail, respectively. Percent BF was 35.9±0.13, 38.3±0.20 and 40.0±0.46 in the robust, pre-frail and frail individuals, respectively. WC was 99.5±0.32 in the robust, 100.1±0.43 in pre-frail, 104.7±1.17 in frail individuals. Compared to robust individuals, only frail individuals had greater %BF on average (ß=0.97±0.43,p=0.03); however, pre-frail and frail individuals had 2.18 and 4.80 greater WC, respectively (ß=2.18±0.64,p=0.002, and ß=4.80±1.1,p<0.001). CONCLUSION: Our results demonstrate that in older adults, frailty and pre-frailty are associated with a greater likelihood of high WC (as dichotomized) and a greater average WC (continuous).

MRI follow-up after free tendon graft reconstruction of the thumb ulnar collateral ligament.

OBJECTIVE: Our aim was to analyse whether MRI is useful in the follow-up of reconstruction of the ulnar collateral ligament (UCL) of the metacarpophalangeal joint of the thumb, to describe normal postoperative findings, and to evaluate different MR sequences. MATERIAL AND METHODS: Our study material consists of 10 patients who, because of a chronic rupture of the ulnar collateral ligament of the thumb, had been operatively treated using a free tendon graft. The patients were, in addition to the clinical examination and radiographs, also imaged using MRI both pre- and postoperatively. The postoperative MRI controls, undertaken at 2, 12 and 24 months were analysed without knowledge of the clinical or radiographic findings. RESULTS: The reconstructed UCL was well visualised on MRI. One graft rupture was diagnosed on MRI and was later operatively confirmed. No increase in osteoarthritis of the metacarpophalangeal (MP) joint of the thumb was seen during the follow-up. The single most informative MR sequence was T2TSE in the coronal plane. CONCLUSION: Magnetic resonance imaging may provide a clinically valuable means of assessing graft integrity in patients with suspected postoperative graft failure after UCL reconstruction, although we do not consider MRI necessary in the routine follow-up of patients with an uneventful recovery.

The posterior transtriceps approach for elbow arthrography: a forgotten technique?

OBJECTIVE: To evaluate the technical feasibility of performing elbow MR arthrography via a posterior approach through the triceps. MATERIALS AND METHODS: The images of 19 patients with elbow MR arthrography via a posterior transtriceps approach were retrospectively studied. The injections were performed by four musculoskeletal radiologists, using fluoroscopic guidance and a 22- or 25-gauge needle. The fluoroscopic and subsequent MR images were reviewed by two musculoskeletal radiologists and evaluated for adequacy of joint capsular distention, degree and location of contrast leakage, and presence of gas bubbles. RESULTS: The injection was diagnostic in all 19 patients, with a sufficient amount of contrast agent seen in the elbow joint. No significant contrast leakage occurred in 12 patients who received injections of 8 cc or less of contrast agent, but moderate contrast leakage occurred in 6/7 patients who received injections of greater than 8 cc. Contrast leakage generally occurred within the triceps myotendinous junction. No gas bubbles were identified in the injected joints. CONCLUSION: Patients often present for MR arthrography of the elbow with medial or lateral elbow pain. Contrast leakage during a radiocapitellar approach may complicate evaluation of the lateral collateral ligament or the common extensor tendon origin. Transtriceps MR arthrography offers an alternative to the more commonly used radiocapitellar approach. With injected volumes not exceeding 8 cc, the risk of significant contrast leakage is small. An advantage of the transtriceps injection is that contrast leakage through the posterior needle tract does not interfere with evaluation of the lateral structures.

Comparison of standard anteroposterior knee and hip-to-ankle radiographs in determining the lower limb and implant alignment after total knee arthroplasty.

BACKGROUND AND AIMS: The coronal alignment of the lower limb is important for planning and assessing outcome after total knee arthroplasty. This study compared postoperative estimation of alignment and measurement of angles using both hip-to-ankle radiographs and anteroposterior (AP) knee radiographs in standing position. PATIENTS AND METHODS: Consecutive standard AP knee and hip-to-ankle radiographs in 83 patients (103 knees) after total knee arthroplasty were analyzed. RESULTS: The tibiofemoral angle measured from both hip-to-ankle and knee radiographs correlated moderately with the mechanical axis (r = 0.646 and r = 0.540, respectively). The correlation between tibiofemoral angles in the two radiographs was excellent (r = 0.860). Furthermore, measurements of tibial and femoral component alignment between the two radiographs correlated highly (r = 0.718 and r = 0.773, respectively). Intra- and interobserver correlations were high in all analyses. CONCLUSIONS: The standard AP knee radiograph appears to be a valid alternative to the hip-to-ankle radiograph for determining knee coronal plane alignment in routine followup after total knee arthroplasty. However, the hip-to-ankle radiograph alone provides accurate information on weight-bearing mechanical axis in patients with suspected lower limb malalignment.

Ultrasound guidance for puncture and injection in the radiocarpal joint.

BACKGROUND: The use of intra-articular contrast agent has been shown to increase the diagnostic accuracy of wrist magnetic resonance (MR) in patients with suspected trauma of the wrist ligaments. Traditionally, the contrast agent has been applied under fluoroscopic guidance. PURPOSE: To present a method based on ultrasound guidance for the injection of intra-articular contrast agent in wrist MR. MATERIAL AND METHODS: One hundred eight patients (56 female and 52 male, mean age 36 years) referred for wrist MR arthrograms due to suspected ligament rupture were included in this retrospective study. The preferred injection point is about 1 cm distal to Lister's tubercle in the distal radius. A correct positioning of the injection needle can be ensured using ultrasound guidance. RESULTS: Using this technique, the injection was intra-articular in 93.5% of the 108 injections over a 2-year learning period. CONCLUSION: Ultrasound guidance of the contrast injection in radiocarpal MR arthrograms is a cost-effective and safe alternative to fluoroscopically guided procedures. Furthermore, the use of ultrasound guidance provides clues about possible fluid collections within the joint.

Acute paediatric ankle trauma: MRI versus plain radiography.

OBJECTIVE: To evaluate the diagnosis of acute physeal ankle fractures on plain radiographs using MRI as the gold standard. METHODS: Sixty consecutive children, 29 with a clinical diagnosis of lateral ligament injury and 31 with physeal ankle fractures, were examined using both radiographs and MRI in the acute period. The imaging data were reviewed by three "masked" radiologists. The fracture diagnosis and Slater-Harris classification of radiographs were compared with findings on MRI. RESULTS: Plain radiography produced five of 28 (18%) false negative and 12 of 92 (13%) false positive fracture diagnoses compared with MRI. Six of the 12 false positive fractures were due to a misclassification of lateral ligament disruption as SH1 fractures, Altogether a difference was found in 21% of cases in either the diagnosis or the classification of the fractures according to Salter-Harris. All bone bruises in the distal tibia and fibula and 64% of bone bruises in the talus were seen in association with lateral ligament injuries. Talar bone bruises in association with fractures occurred on the same side as the malleolar fracture; talar bone bruises in association with lateral ligament disruption were seen in different locations. The errors identified on radiographs by MRI did not affect the management of the injury. CONCLUSIONS: The incidence of false negative ankle fractures in plain radiographs was small and no complex ankle fractures were missed on radiographs. The total extent of complex fractures was, however, not always obvious on radiographs. In an unselected series of relatively mild ankle injuries, we were unable to show a single case where the treatment or prognosis based on plain radiography should have been significantly altered after having done a routine MRI examination. Plain radiography is still the diagnostic cornerstone of paediatric ankle injuries.

MR findings in humeral epicondylitis. A systematic review.

PURPOSE: To highlight the importance of meta-analysis in diagnostic imaging by presenting a systematic search of the literature on the accuracy of MR imaging in epicondylitis. MATERIAL AND METHODS: The literature was comprehensively reviewed to identify studies on MR findings in epicondylitis. Reviewers blind to the clinical diagnoses screened the data according to predetermined inclusion criteria. Data were collected and validity and relevance were assessed on structured forms. RESULTS: Seven studies including 148 patients with epicondylitis were accepted for the analysis. Eleven asymptomatic contralateral elbows and 29 elbows of healthy volunteers served as controls. The volunteers were distinctly younger than the patients. The MR technique was divergent, and the observed pathological changes also varied. The most frequent alteration was a change in the common extensor tendon signal (90%, 95% confidence interval 84-94%); 14% of the healthy volunteers and 50% of the contralateral elbows displayed the similar alteration. CONCLUSION: Small sample size and methodological shortcomings in the original studies make the assessment of MR findings in epicondylitis questionable. There is a need for well-designed studies in which clinical features and occupational backgrounds as well as imaging parameters are carefully documented.

MRI abnormalities of foot and ankle in asymptomatic, physically active individuals.

OBJECTIVE: To assess MRI changes in the ankle and foot after physical exercise. DESIGN AND PATIENTS: Nineteen non-professional marathon runners and 19 age- and sex-matched controls volunteered for the study. All had ankle and foot MR images (1.5 T) taken in three perpendicular planes (STIR, T2F and T1FS sequences) within 3 h of running a full-length marathon (42.125 km). Three radiologists independently analysed the groups on a masked basis using a predefined form. RESULTS: Severe bone marrow oedema was seen in one and slight bone marrow oedema in three marathon runners. Slight bone marrow oedema was found in three control subjects. Signal alteration within the soleus muscle, consistent with a grade 1 strain, was found in one marathon runner. Small punctate hyperintensities within the Achilles tendon were seen in 26% of the marathon runners and in 63% of controls (P = 0.016). An increased amount of fluid in the retrocalcaneal bursa was found in one control and in none of the marathon runners. Small amounts of fluid in the retrocalcaneal bursa were seen in 68% of marathon runners and in 53% of controls. Grade 1 or 2 peritendinous joint fluid was found around 22% of tendons, among both marathon runners and controls, most often involving the tendon sheath of the flexor hallucis longus muscle. An increased amount of joint fluid was noted in 34% of the joints of the marathon runners, and in 18% of the controls. CONCLUSION: MRI shows several abnormalities in the ankle and foot both after marathon races and in asymptomatic physically active individuals without any preceding extraordinary strain. Recreational sports may lead to a number of positive MRI findings without correlation with clinical findings.

MR imaging in chronic rupture of the ulnar collateral ligament of the thumb.

PURPOSE: MR imaging has been shown as the best radiologic method for verifying and classifying acute ulnar collateral ligament (UCL) ruptures of the thumb. Our aim was to analyse the usefulness of MR also in old ruptures and to establish the most useful sequences. MATERIAL AND METHODS: Ten patients with an old UCL rupture of the thumb were preoperatively imaged using 1.5 T MR. Three radiologists blinded to the findings separately analysed the MR images of these patients and of 10 age-and sex-matched voluntary controls. MR findings of the patients were compared with those of surgery. RESULTS: The consensus diagnosis of an UCL rupture was accurate in all 10 patients. All controls were classified as having no UCL rupture. In 5 of the 7 patients with a surgically defined Stener or non-Stener lesion, the consensus diagnosis was the same as the operative diagnosis. Due to excessive scarring it was not possible to verify any Stener lesion intra-operatively in 3 patients. The most informative MR sequence was T2 TSE in the coronal plane, the second most informative was T1 SE with fat suppression in the coronal plane. CONCLUSION: An old UCL rupture is well verified by MR but typing of the lesion as either a Stener or non-Stener type is not always possible.

Regular-dose versus high-dose omeprazole in peptic ulcer bleeding: a prospective randomized double-blind study.

BACKGROUND: It has been suggested that profound acid inhibition along with endoscopic therapy might prevent rebleeding and reduce mortality in patients with peptic ulcer bleeding. The aim of the study was to test the possible equivalence of a high dose and the regular dose of omeprazole in peptic ulcer bleeding. METHODS: We performed a prospective randomized double-blind study involving 142 patients with acute peptic ulcer bleeding (Forrest classification I-II: spurting or oozing bleeding, non-bleeding visible vessel, clot and black base). One-hundred-and-two (71.8%) patients received endoscopic treatment (adrenaline injection and/or heater probe) in pre-entry. Patients were randomly assigned to receive the regular dose of omeprazole intravenously (20 mg once a day for 3 days, i.e. 60 mg/72 h) or a high dose of omeprazole (80 mg bolus + 8 mg/h for 3 days, i.e. 652 mg/72 h). Rebleeding, surgery and death were the outcome measures. RESULTS: Six (8.2%) of the 73 patients receiving the regular dose of omeprazole and 8 (11.6%) of the 69 patients receiving the high dose of omeprazole rebled (P = 0.002 for equivalence, equivalence limit 0.15). Three (4.1%) of the former patients and 5 (7.2%) of the latter group underwent surgery. Four (5.5%) patients in the regular-dose and 2 (2.9%) in the high-dose group died within 30 days. CONCLUSION: Under the defined tolerance limits, the regular dose of omeprazole is as successful as a high dose in preventing peptic ulcer rebleeding.

MR imaging in suspected acute trauma of wrist bones.

OBJECTIVE: The purpose of this study was to evaluate the findings of MR imaging compared to plain radiography in acute wrist trauma. METHODS: Radiography and MR imaging (obtained at 1.5 T) of 67 patients (38 female, 29 male, aged 15-80 years) were analysed by three senior radiologists in a blinded random fashion. RESULTS: One-third (n= 13) of the 37 fractures observed on MR images were missed on the radiographs. The McNemar test indicated significant differences in diagnoses between radiography and MR. CONCLUSION: We recommend that MR imaging should be considered in the diagnosis of acute wrist trauma when: 1) There is a clear discrepancy between the clinical status and a negative radiography and when splint treatment would increase cost by causing occupational restrictions; and 2) Healing of trauma diagnosed as contusion or distension does not occur within the expected time.

MR imaging in biofix-osteosynthesis.

PURPOSE: Osteosynthesis by means of bioresorbable implants, mostly of self-reinforced poly-L-lactide (SR-PLLA), has been used in humans for about 10 years. The aim of this study was to examine the controversy between histological studies confirming fragmentation of the biomaterial and radiological studies showing no breaking of the material. MATERIAL AND METHODS: Six patients with displaced malleolar fractures operatively treated with biodegradable SR-PLLA screws underwent MR examinations at 1.5 T, immediately postoperatively and after one to two years. RESULTS: The biodegradable osteosynthetic screws were clearly seen on all MR images. Of 12 screws, 6 were broken at the final examination (5 syndesmotic transfixation screws and 1 screw through the growth cartilage). CONCLUSION: The breaking of a biodegradable osteosynthesis is possible to document on MR images.

Decreased striatal monoaminergic terminals in olivopontocerebellar atrophy and multiple system atrophy demonstrated with positron emission tomography.

We used [11C]dihydrotetrabenazine, a new ligand for the type 2 vesicular monoamine transporter (VMAT2), with positron emission tomography to study striatal monoaminergic presynaptic terminals in 4 patients with multiple system atrophy, 8 with sporadic olivopontocerebellar atrophy, and 9 normal control subjects. Specific binding in the striatum was significantly reduced in the multiple system atrophy patients as compared with the normal control group, with average reductions of 61% in the caudate nucleus (p = 0.002) and 58% in the putamen (p = 0.009). Smaller reductions were found in the sporadic olivopontocerebellar atrophy group, averaging 26% in the caudate nucleus (p = 0.05) and 24% in the putamen (p = 0.11). Mean blood-to-brain [11C]dihydrotetrabenazine transport (K1) was significantly different between groups only in the cerebellum, with values for the sporadic olivopontocerebellar atrophy group diminished compared with the normal control group. Cerebellar K1 was not significantly decreased in the multiple system atrophy group. The finding of reduced striatal VMAT2 in sporadic olivopontocerebellar atrophy patients suggests nigrostriatal pathology, indicating that some may later develop symptomatic extrapyramidal disease.

Positron emission tomographic studies of cerebral benzodiazepine-receptor binding in chronic alcoholics.

Positron emission tomography was used with [11C]flumazenil (FMZ) and [18F]fluorodeoxyglucose to study GABA type A/benzodiazepine (GA-BA-A/BDZ) receptors and cerebral metabolic rates for glucose (1CMRg1c) in 17 male patients with severe chronic alcoholism (ALC), 8 with (ACD) and 9 without alcoholic cerebellar degeneration (non-ACD). In comparison with male normal controls of similar ages, the ALC group had significantly reduced FMZ ligand influx (K1), FMZ distribution volume (DV), and 1CMRg1c bilaterally in the medial frontal lobes, including superior frontal gyrus and rostral cingulate gyrus; the ACD group had significant reductions of K1, DV, and 1CMRg1c bilaterally in the same distribution, and also in the superior cerebellar vermis; and the non-ACD group had significant reductions of K1, DV, and 1CMRg1c bilaterally in the same regions of the frontal lobes but not in the superior cerebellar vermis. When compared with the non-ACD group, the ACD group had significant reductions of K1, and DV bilaterally in the superior cerebellar vermis. The results suggest that severe chronic alcoholism damages neurons containing GA-BA-A/BDZ receptors in the superior medial aspects of the frontal lobes, and in patients with clinical signs of ACD, neurons containing GABA-A/BDZ receptors in the superior cerebellar vermis.

Characteristics of the dysarthria of multiple system atrophy.

OBJECTIVE: To characterize the dysarthria in patients with multiple system atrophy (MSA). DESIGN: Motor speech examinations, consisting of oral motor, oral agility, and perceptual speech analysis, were performed on 46 patients with MSA. SETTING: University department of neurology referral center. RESULTS: All patients had dysarthria with combinations of hypokinesia, ataxia, or spasticity. Thirty-two patients had all 3 components, 13 had 2 components, and 1 had only 1 component. In most patients the hypokinetic components were the most severe. Hypokinetic components predominated in 22 patients (48%), whereas ataxic components predominated in 16 (35%), and spastic components in 5 (11%). In 1 patient (2%) the hypokinetic and spastic components were equal and greater than the ataxic components, and in 1 patient (2%) the hypokinetic and ataxic components were equal and greater than the spastic components. One patient (2%) had only ataxic dysarthria. The predominant type of dysarthria corresponded well to the subtype of MSA. CONCLUSIONS: The finding of a mixed dysarthria with combinations of hypokinetic, ataxic, and spastic components is consistent with both the overall clinical and the neuropathologic changes in MSA. Motor speech examination can provide helpful information in evaluating patients who might have MSA.

Spinocerebellar ataxia type 1 with multiple system degeneration and glial cytoplasmic inclusions.

Spinocerebellar ataxia type 1 (SCA1) is a dominantly inherited progressive neurological disorder characterized by neuronal degeneration and reactive gliosis in the cerebellum, brainstem, spinocerebellar tracts, and dorsal columns. Multiple system atrophy is a sporadic progressive neurological disorder with degeneration and gliosis in the basal ganglia, cerebellum, brainstem, and spinal autonomic nuclei, and with argyrophilic glial cytoplasmic inclusions. We describe 4 members of a family with the SCA1 mutation and a dominantly inherited progressive ataxia in which autopsy examination of 1 member showed neuropathological changes typical of multiple system atrophy, including glial cytoplasmic inclusions. In this patient, magnetic resonance imaging revealed marked brainstem and cerebellar volume loss and mild supratentorial generalized volume loss. Positron emission tomography with [18F]fluorodeoxyglucose revealed widespread hypometabolism in a pattern found in sporadic multiple system atrophy and not in dominantly inherited olivopontocerebellar atrophy. Positron emission tomography with [11C]flumazenil revealed normal benzodiazepine receptor distribution volumes, similar to those seen in sporadic multiple system atrophy. Two other family members still living had similar changes in the imaging studies. The findings in this family suggest that the SCA1 gene mutation can result in a disorder similar to multiple system atrophy, both clinically and neuropathologically.

Benzodiazepine receptor binding in cerebellar degenerations studied with positron emission tomography.

We used positron emission tomography with [11C]flumazenil to study gamma-aminobutyric acid type A/benzodiazepine receptor binding quantitatively in the cerebral hemispheres, basal ganglia, thalamus, cerebellum, and brainstem of 72 subjects, including 14 with multiple system atrophy of the ataxic (olivopontocerebellar atrophy) type, 5 with multiple system atrophy of the extrapyramidal/autonomic (Shy-Drager syndrome) type, 18 with sporadic olivopontocerebellar atrophy, 15 with dominantly inherited olivopontocerebellar atrophy, and 20 normal control subjects with similar age and sex distributions. In comparison with data obtained from the normal control subjects, we found significantly decreased ligand influx in the cerebellum and brainstem of multiple system atrophy patients of the olivopontocerebellar atrophy type and in patients with sporadic olivopontocerebellar atrophy, but not in patients with multiple system atrophy of the Shy-Drager syndrome type. Despite these differences in ligand influx, benzodiazepine binding was largely preserved in the cerebral hemispheres, basal ganglia, thalamus, cerebellum, and brainstem in patients with multiple system atrophy of both types as well as those with sporadic or dominantly inherited olivopontocerebellar atrophy as compared with normal control subjects. The finding of relative preservation of benzodiazepine receptors indicates that these sites are available for pharmacological therapy in these disorders.