Search PubMed⌕ Search

Biomedical subjects

J N Caviness

Publications and source records attributed to J N Caviness.

At least 19 recordsLinked to original sources
PubMed2006

Nonvasculitic autoimmune inflammatory meningoencephalitis imitating Creutzfeldt-Jakob disease.

BACKGROUND: Nonvasculitic autoimmune inflammatory meningoencephalitis and Creutzfeldt-Jakob disease can present as rapidly progressive encephalopathies with similar clinical features. Slowing of background rhythm is an electroencephalographic characteristic shown by both, but persistent periodic sharp waves are more specific for Creutzfeldt-Jakob disease and have not been reported in nonvasculitic autoimmune inflammatory meningoencephalitis or related autoimmune meningoencephalitides. OBJECTIVE: To describe a patient with clinical (rapidly progressive myoclonus, dementia, and Parkinsonism) and electroencephalographic findings (persistent periodic sharp waves) that diagnostically suggest Creutzfeldt-Jakob disease. DESIGN AND SETTING: A case report at the Mayo Clinic Arizona, Scottsdale. RESULTS: The patient made a dramatic recovery with resolution of the periodic sharp wave complexes after treatment with high-dose corticosteroids. Our case is the first reported case of a patient with probable nonvasculitic autoimmune inflammatory meningoencephalitis and electroencephalographic periodic complexes suggestive of Creutzfeldt-Jakob disease. CONCLUSION: Rapidly progressive encephalopathy with periodic sharp wave complexes can be associated with a reversible autoimmune syndrome.

Adrenal Cortex Hormones↗
PubMed2005

Is the functional decline of Parkinson's disease similar to the functional decline of Alzheimer's disease?

Since many Parkinson's disease (PD) subjects develop dementia, we determined whether the correlation between functional and cognitive decline seen in Alzheimer's disease (AD) is seen in PD. Seventy-five PD subjects with and without dementia and 103 AD/MCI subjects underwent the Functional Assessment Staging (FAST), the Global Deterioration Scale (GDS), the UPDRS motor portion, and the MMSE. In AD/MCI subjects, changes in FAST and GDS scores correlated with MMSE (rho=-0.814, P<0.001; rho=-0.840, P<0.001, respectively). In PD subjects, the FAST and GDS also correlated with MMSE (rho=-0.675, P<0.001; rho=-0.647, P<0.001, respectively). The UPDRS correlated with the GDS and FAST more closely in PD than in AD. Similar to AD, functional declines in PD correlates with cognitive decline and may be influenced by motor disability in PD.

Activities of Daily Living↗
PubMed2004

Ropinirole for restless legs syndrome: a placebo-controlled crossover trial.

The authors performed a double-blind, placebo-controlled, crossover study of ropinirole (0.5 to 6.0 mg/day) for restless legs syndrome (RLS). The RLS Rating Scale score improved (p < 0.001) from a mean (SD) of 25 (7) during placebo treatment to 13 (12) during ropinirole treatment. Eight of the 22 patients had complete resolution of symptoms on ropinirole. Adverse events included nausea and dizziness. Ropinirole was effective and well tolerated for treating the symptoms of RLS.

Adult↗
PubMed2002

Loss of response to levodopa in Parkinson's disease and co-occurrence with dementia: role of D3 and not D2 receptors.

Previous data suggest a relationship between the loss of response to levodopa in Parkinson's disease (PD) patients with the co-occurrence of dementia, but the role of alterations in the dopamine system has not been explored. We measured the extent of striatal DA loss and changes in striatal DA D(2) and D(3) receptors in postmortem striatum of PD patients who historically had or had not lost their clinical response to dopaminergic drugs and/or had an additional diagnosis of dementia. Clinical evaluation and retrospective chart reviews for PD and dementia, and neuropathological diagnoses were obtained. All PD cases (+/-dementia), regardless of response to dopaminergic drugs, exhibited a significant and similar degree and pattern of loss of tyrosine hydroxylase immunocytochemistry and DA transporter binding in striatum, and loss of tyrosine hydroxylase-immunoreactive neurons and brain-derived neurotrophic-immunoreactive neurons from the ventral midbrain. D(2) receptor concentrations were modestly elevated in the rostral striatum of all the PD cases (+/-dementia), whether or not they continued to respond to dopaminergic drugs. In contrast, loss of D(3) receptor concentration correlated with loss of response to dopaminergic drugs, independent of the presence or absence of dementia. A maintained response to dopaminergic drugs correlated with an elevation of D(3) receptors. Dementia with PD was highly correlated with a loss of response to dopaminergic drugs, and was also correlated with reduced D(3) receptors. The alterations in D(3) receptor concentrations were greatest in the nucleus accumbens, caudal striatum, and globus pallidus. Thus, loss of dopamine D(3) receptors may be a more important contributing factor to a loss of response to dopaminergic drugs than changes in the D(2) receptor.

Aged↗
PubMed2002

Gender and pramipexole effects on levodopa pharmacokinetics and pharmacodynamics.

The authors studied the pharmacokinetics of levodopa (LD) with and without pramipexole (PPX) in men and postmenopausal women with PD. Patients on stable dose of carbidopa/LD were randomized to receive escalating doses of placebo or PPX over 7 weeks. LD and PPX pharmacokinetics were performed after a single test dose 25/100 of carbidopa/LD, before initiation of PPX or placebo, at 1.5 mg/d and 4.5 mg/d of PPX or placebo. Compared to men, women had greater LD bioavailability. PPX did not alter LD bioavailability, and PPX pharmacokinetics were equivalent in men and women.

Aged↗
PubMed2002

Motor unit number estimates in idiopathic Parkinson's disease.

We previously reported changes in motor unit morphology in patients with Parkinson's disease (PD) using subjective and computerized quantitative electromyography. Now, we present data on motor unit number estimates (MUNE) to address the hypothesis of motor neuron dropout in PD. Twenty patients with PD and 20 age-matched control subjects were screened by clinical criteria and nerve conduction studies to exclude those with neuropathy. Motor unit number estimates in the extensor digitorum brevis and hypothenar group were assessed by three different MUNE techniques. The MUNE technique types included (1) the statistical method developed by Daube, (2) a threshold method, and (3) an F-wave method. The overall multivariate comparison for the six MUNE measurements was significantly lower for the patients than the controls (P=0.02). The only significant difference in the individual measures was found in the threshold MUNE method of the hypothenar group (P<0.05). These results are consistent with those of our previous work, and both support the hypothesis that mild motor neuron dropout occurs in idiopathic PD. However, MUNE methods characteristically have large standard deviations which make it difficult to detect small changes. Progress in decreasing the variance of MUNEs will facilitate their use in detecting small motor unit number changes in neurodegenerative disease.

Aged↗
PubMed2001

A randomized, double masked, controlled trial of botulinum toxin type A in essential hand tremor.

OBJECTIVE: To evaluate the safety and efficacy of botulinum toxin type A injection in essential tremor of the hand. BACKGROUND: Botulinum toxin type A is an effective treatment for dystonia, spasticity, and other movement disorders and has been found to be useful in open-label studies and one double-masked study of essential hand tremor. METHODS: One hundred thirty-three patients with essential tremor were randomized to low-dose (50 U) or high-dose (100 U) botulinum toxin type A (Botox) or vehicle placebo treatment. Injections were made into the wrist flexors and extensors. Patients were followed for 16 weeks. The effect of treatment was assessed by clinical rating scales, measures of motor tasks and functional disability, and global assessment of treatment. Hand strength was evaluated by clinical rating and by a dynamometer. RESULTS: Both doses of botulinum toxin type A significantly reduced postural tremor on the clinical rating scales after 4 to 16 weeks. However, kinetic tremor was significantly reduced only at the 6-week examination. Measures of motor tasks and functional disability were not consistently improved with botulinum toxin type A treatment. Grip strength was reduced for the low- and high-dose botulinum toxin type A groups as compared with the placebo group. Adverse reactions consisted mainly of dose-dependent hand weakness. CONCLUSION: Botulinum toxin type A injections for essential tremor of the hands resulted in significant improvement of postural, but not kinetic, hand tremors and resulted in limited functional efficacy. Hand weakness is a dose-dependent significant side effect of treatment at the doses used in this study.

Aged↗
PubMed2001

Serum leptin concentrations and satiety in Parkinson's disease patients with and without weight loss.

We compared serum leptin and satiety measures in 18 Parkinson's disease (PD) patients with unintended weight loss (WL) and 18 PD patients whose weight was stable (WS). Mean serum leptin concentrations tended to be lower in WL than WS patients, but this did not reach statistical significance. Body mass index correlated with serum leptin concentrations. Ratings of hunger, satiety, fullness, and thirst did not differ between groups. However, the mean sensation of fullness before meals correlated with serum leptin in the entire cohort of patients, particularly in the WL group. The results indicate that unintended weight loss in PD patients is unlikely to be due to abnormal serum leptin concentrations.

Aged↗
PubMed2001

Persistent chorea triggered by hyperglycemic crisis in diabetics.

Five female patients developed chorea concurrent with, or shortly after a hyperglycemic episode (admission glucose values 500-1,000 mg/dL). In four of these five patients, there was no prior history of diabetes mellitus. The chorea continued despite correction of blood glucose and persisted to the time of last follow-up, 6 months to 5 years later. The chorea developed subacutely over 2 days to 1 month and was generalized in one, unilateral in three, and involved right > left lower extremity in the other; the severity initially reached ballistic proportions in two. Associated clinical features were nil in four of these patients, but cognitive impairment and personality change occurred in one. The histories and laboratory studies identified no predisposing factors other than the hyperglycemia. The chorea was sufficiently troublesome to require administration of neuroleptic medication in all five cases. Four of the five cases had high signal intensity within basal ganglia on T1-weighted magnetic resonance (MR) imaging, as has previously been described; however, this was not seen in one case (who had the most severe clinical condition). Most previously described cases have involved a reversible clinical syndrome, in contrast to our patients. The pathogenic mechanisms remain uncertain.

Acute Disease↗
PubMed2000

Electrophysiological observations in hereditary parkinsonism-dementia with Lewy body pathology.

We studied the only two living affected individuals who are part of a previously reported kindred that expresses a hereditary parkinsonism-dementia syndrome with Lewy body pathology. The electrophysiological characteristics of the hyperkinetic movement disorders in these patients were examined to provide physiological insights into the clinical phenotype of this syndrome. Evaluation of both patients showed 7-9 Hz electromyographic discharges in upper extremity muscles during postural activation, and one patient showed a 4-5 Hz discharge pattern correlating to a rest tremor. Brief (<50 ms) myoclonic electromyographic discharges were seen in both patients, and a time-locked relationship to a focal cortical premovement electroencephalographic potential was elicited in one patient. Somatosensory evoked potentials were not enlarged and long latency reflexes were not enhanced. Electroencephalography was normal in one patient but showed pathologic slow frequencies in the other. The electrophysiological findings show evolution which correlates with an apparent characteristic evolution of hyperkinetic movement disorders that accompanies the severe progression of parkinsonism-dementia in this kindred. These results have implications for the future study of this and similar syndromes.

Adult↗
PubMed2000

Motor unit changes in sporadic idiopathic Parkinson's disease.

We studied motor unit changes in 20 patients with Parkinson's disease (PD) and 20 age-matched control subjects to look for evidence of motorneuron degeneration in sporadic idiopathic PD. Patients and control subjects were screened by clinical criteria and nerve conduction studies to exclude those with peripheral neuropathic processes. Changes in motor unit morphology were investigated with subjective and computerized quantitative electromyography (QEMG) of the anterior tibialis (AT) and first dorsal interosseous. Multivariate comparisons showed a significant difference in the QEMG analysis for motor unit enlargement in patients with PD versus control subjects. Some of the univariate comparisons for both the subjective and QEMG analyses of the AT were also significant. These results demonstrate that motorneuron drop-out with reinnervation occurs in sporadic idiopathic PD. In summary, our findings provide evidence that clinically silent motorneuron disease occurs in typical cases of sporadic idiopathic PD, suggesting that it may be a normal part of the pathologic picture of PD. Any hypothesis concerning the pathogenic mechanism of PD would need to take into account such a finding.

Aged↗
PubMed2000

Amantadine is beneficial in restless legs syndrome.

Twenty-one patients (mean age 70 yrs) with restless legs syndrome (RLS) were treated with amantadine in an open-label trial. Amantadine was started at 100 mg per day and was increased every 3-5 days by 100 mg (up to a maximum of 300 mg per day) until significant relief of symptoms or intolerable side effects were experienced. Patients were rated pre- and posttreatment using an RLS rating scale (0-10). Each patient also rated the degree of response in a continuous scale from 0% (no improvement) to 100% (complete improvement). Eleven of 21 (52%) had subjective benefit to amantadine, with degree of response ranging from 25%-100% (mean 69%) among responders. Six had 95%-100% improvement. The RLS score for all 21 patients dropped from a mean (+/- standard deviation) of 9.8 +/- 0.6 (range, 8-10) pretreatment to 6.6 +/- 3.8 (range, 0-10) posttreatment (p = 0.001). The duration of response was 0-13 months (mean, 3.6 +/- 4.5), with nine responders still remaining on the drug as of last follow up. The mean effective dose was 227 mg per day. The most common side effects were drowsiness (3), fatigue (2), and insomnia (2); only two stopped amantadine because of side effects. We conclude that amantadine is an effective and well-tolerated drug for RLS.

Aged↗
PubMed2000

Lexical boundary error analysis in hypokinetic and ataxic dysarthria.

This investigation is the second in a series to examine a potential source of reduced intelligibility in dysarthric speech, namely the mismatch between listeners' perceptual strategies and the acoustic information available in the dysarthric speech signal. Lexical boundary error (LBE) analysis was conducted on listener transcripts from phrases produced by speakers with hypokinetic dysarthria, ataxic dysarthria, and normal controls. By design, the hypokinetic and ataxic dysarthric tapes elicited similar intelligibility (words-correct) scores. However, they elicited different numbers and patterns of lexical boundary errors. The nature of the error pattern differences can be traced to the listeners' use of available syllabic strength information to segment the acoustic stream. Specifically, although both dysarthric speech samples elicited numerous lexical boundary errors, those for the hypokinetic speech generally conformed to predictions offered from studies of degraded normal speech. Those for the ataxic speech did not conform strongly to such predictions. It appears that the prosodic deficits of the ataxic speech (tendency toward syllabic isochrony, excessive loudness variation, and reduced vowel working space consequent to reductions in vowel strength) posed more of a problem for listeners than did the prosodic deficits of the hypokinetic speech (rapid rate, monotony, reduced vowel working space).

Adolescent↗
PubMed2000

Primary care guide to myoclonus and chorea. Characteristics, causes, and clinical options.

Myoclonus and chorea are hyperkinetic movement disorders that confer a jerky appearance. Myoclonus involves a quick and simple jerk, whereas the jerking in chorea combines with other, slower movements in a continuous, flowing fashion. Both disorders have many different causes, and diagnosis requires knowledge of common clinical characteristics and directed ancillary testing. Symptomatic treatment is available, but reversal of the underlying cause should be considered first if possible. The potential benefits of treatment must be weighed against the risk of drug side effects.

Chorea↗
PubMed2000

Hereditary ataxias.

There are many causes of hereditary ataxia. These can be grouped into categories of autosomal recessive, autosomal dominant, and X-linked. Molecularly, many of them are due to trinucleotide repeat expansions. In Friedreich ataxia, the trinucleotide repeat expansions lead to a "loss of function." In the dominant ataxias, the expanded repeats lead to a "gain of function," most likely through accumulation of intranuclear (and less commonly cytoplasmic) polyglutamine inclusions. Channelopathies can also lead to ataxia, especially episodic ataxia. Although phenotypic characteristics are an aid to the clinician, a definitive diagnosis is usually made only through genotypic or molecular studies. Genetic counseling is necessary for the testing of symptomatic and asymptomatic individuals. No effective treatment is yet available for most ataxic syndromes, except for ataxia with isolated vitamin E deficiency and the episodic ataxias.

Ataxin-1↗