Limb and trunk accelerometer data collected with wearable sensors from subjects with Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disorder characterized by motor and non-motor symptoms. Dyskinesia and motor fluctuations are complications of PD medications. An objective measure of on/off time with/without dyskinesia has been sought for some time because it would facilitate the titration of medications. The objective of the dataset herein presented is to assess if wearable sensor data can be used to generate accurate estimates of limb-specific symptom severity. Nineteen subjects with PD experiencing motor fluctuations were asked to wear a total of five wearable sensors on both forearms and shanks, as well as on the lower back. Accelerometer data was collected for four days, including two laboratory visits lasting 3 to 4 hours each while the remainder of the time was spent at home and in the community. During the laboratory visits, subjects performed a battery of motor tasks while clinicians rated limb-specific symptom severity. At home, subjects were instructed to use a smartphone app that guided the periodic performance of a set of motor tasks.

Accelerometer data collected with a minimum set of wearable sensors from subjects with Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disorder associated with motor and non-motor symptoms. Current treatments primarily focus on managing motor symptom severity such as tremor, bradykinesia, and rigidity. However, as the disease progresses, treatment side-effects can emerge such as on/off periods and dyskinesia. The objective of the Levodopa Response Study was to identify whether wearable sensor data can be used to objectively quantify symptom severity in individuals with PD exhibiting motor fluctuations. Thirty-one subjects with PD were recruited from 2 sites to participate in a 4-day study. Data was collected using 2 wrist-worn accelerometers and a waist-worn smartphone. During Days 1 and 4, a portion of the data was collected in the laboratory while subjects performed a battery of motor tasks as clinicians rated symptom severity. The remaining of the recordings were performed in the home and community settings. To our knowledge, this is the first dataset collected using wearable accelerometers with specific focus on individuals with PD experiencing motor fluctuations that is made available via an open data repository.

Factors associated with falling in early, treated Parkinson's disease: The NET-PD LS1 cohort

BACKGROUND

Recognizing the factors associated with falling in Parkinson's disease (PD) would improve identification of at-risk individuals.

OBJECTIVE

To examine frequency of falling and baseline characteristics associated with falling in PD using the National Institute of Neurological Disorders and Stroke (NINDS) Exploratory Trials in PD Long-term Study-1 (NET-PD LS-1) dataset.

METHODS

The LS-1 database included 1741 early treated PD subjects (median 4year follow-up). Baseline characteristics were tested for a univariate association with post-baseline falling during the trial. Significant variables were included in a multivariable logistic regression model. A separate analysis using a negative binomial model investigated baseline factors on fall rate.

RESULTS

728 subjects (42%) fell during the trial, including at baseline. A baseline history of falls was the factor most associated with post-baseline falling. Men had lower odds of post-baseline falling compared to women, but for men, the probability of a post-baseline fall increased with age such that after age 70, men and women had similar odds of falling. Other baseline factors associated with a post-baseline fall and increased fall rate included the Unified PD Rating Scale (UPDRS) Activities of Daily Living (ADL) score, total functional capacity (TFC), baseline ambulatory capacity score and dopamine agonist monotherapy.

CONCLUSION

Falls are common in early treated PD. The biggest risk factor for falls in PD remains a history of falling. Measures of functional ability (UPDRS ADL, TFC) and ambulatory capacity are novel clinical risk factors needing further study. A significant age by sex interaction may help to explain why age has been an inconsistent risk factor for falls in PD.

Head injury at early ages is associated with risk of Parkinson's disease

INTRODUCTION

The literature on the effect of head injuries on the risk of PD is inconclusive. Some researchers have hypothesized that studies that have seen an effect are simply capturing injury related to pre-clinical PD. However in animal models brain inflammation, which can be initiated by head trauma, has been shown to produce PD-like effects. Furthermore, animal studies have found that early life inflammation in particular is of relevance for PD pathology.

METHODS

We conducted an unmatched case-control study of 379 neurologist confirmed PD patients and 230 controls from the greater Boston, Massachusetts area with questionnaire data on history of head injury and other covariates. We used multivariable logistic regression to estimate adjusted odds ratios (OR) and their corresponding 95% confidence intervals (CI) for PD.

RESULTS

When we excluded injuries that occurred less than 10 years prior to the diagnosis of PD (in order to avoid reverse causation), we found an increased risk of PD associated with a head injury that resulted in a loss of consciousness, but it did not reach statistical significance (OR = 1.57; 95% CI = 0.89-2.80). We found a significant (p = 0.04) effect of age at first head injury. For every 5 year earlier age at first head injury with loss of consciousness the OR for PD was 1.37 (95% CI: 1.01-1.86).

CONCLUSION

Our results suggest that head injury in early life increases the risk of PD.

Validation of an ambulatory capacity measure in Parkinson disease: a construct derived from the Unified Parkinson's Disease Rating Scale

BACKGROUND

A construct calculated as the sum of items 13-15, 29, 30 of the Unified Parkinson's Disease Rating Scale (UPDRS) has been used as an "Ambulatory Capacity Measure" (ACM) in Parkinson disease (PD). Its construct validity has never been examined. A similar construct, consisting of the mean value of the same UPDRS items has been used under the acronym PIGD as a measure of postural instability and gait disorder in PD.

OBJECTIVE

To examine the construct validity of the ACM and PIGD in PD.

METHODS

We analyzed data in an existing database of 340 PD patients, Hoehn and Yahr stages (HYS) 1-5 who participated in a study of falls. Number of falls (NOF) was recorded over 4 weeks, and UPDRS (mental, ADL, and motor subscales), HYS, Activities Based Confidence Scale (ABC), Freezing of Gait Questionnaire (FOG), Five Times Sit-to-Stand (FTSS), Timed Up-and Go (TUG), Gait Velocity (GV), and Berg Balance Scale (BBS) evaluations were performed. Internal consistency was assessed by Cronbach's alpha. Construct validity was assessed through correlations of the ACM and PIGD to these measures and to their summed-ranks. A coefficient of determination was calculated through linear regression.

RESULTS

Mean age was 71.4, mean age at diagnosis 61.4 years; 46% were women; mean UPDRS subscale scores were: Mental 3.7; ADL 15.7; motor: 27.1; mean ACM was 6.51, and mean PIGD 1.30. Cronbach's alpha was 0.78 for both ACM and PIGD. Spearman correlation coefficients between the ACM/PIGD and ABC, FOG, TUG, GV and BBS were 0.69, 0.72, 0.67, 0.58, and 0.70 respectively. Correlation between the ACM/PIGD and summed-ranks of HYS, NOF, ABC, FOG, FTSS, TUG, GV and BBS was high (Spearman r = 0.823, p < 0.0001); 68% of the variability in the summed-ranks was explained by ACM/PIGD.

CONCLUSION

The ACM and the PIGD are valid global measures and accurately reflect the combined effects of the various components of ambulatory capacity in PD patients with HY stages 1-4.

Effect of creatine monohydrate on clinical progression in patients with Parkinson disease: a randomized clinical trial

IMPORTANCE

There are no treatments available to slow or prevent the progression of Parkinson disease, despite its global prevalence and significant health care burden. The National Institute of Neurological Disorders and Stroke Exploratory Trials in Parkinson Disease program was established to promote discovery of potential therapies.

OBJECTIVE

To determine whether creatine monohydrate was more effective than placebo in slowing long-term clinical decline in participants with Parkinson disease.

DESIGN, SETTING, AND PATIENTS

The Long-term Study 1, a multicenter, double-blind, parallel-group, placebo-controlled, 1:1 randomized efficacy trial. Participants were recruited from 45 investigative sites in the United States and Canada and included 1741 men and women with early (within 5 years of diagnosis) and treated (receiving dopaminergic therapy) Parkinson disease. Participants were enrolled from March 2007 to May 2010 and followed up until September 2013.

INTERVENTIONS

Participants were randomized to placebo or creatine (10 g/d) monohydrate for a minimum of 5 years (maximum follow-up, 8 years).

MAIN OUTCOMES AND MEASURES

The primary outcome measure was a difference in clinical decline from baseline to 5-year follow-up, compared between the 2 treatment groups using a global statistical test. Clinical status was defined by 5 outcome measures: Modified Rankin Scale, Symbol Digit Modalities Test, PDQ-39 Summary Index, Schwab and England Activities of Daily Living scale, and ambulatory capacity. All outcomes were coded such that higher scores indicated worse outcomes and were analyzed by a global statistical test. Higher summed ranks (range, 5-4775) indicate worse outcomes.

RESULTS

The trial was terminated early for futility based on results of a planned interim analysis of participants enrolled at least 5 years prior to the date of the analysis (n = 955). The median follow-up time was 4 years. Of the 955 participants, the mean of the summed ranks for placebo was 2360 (95% CI, 2249-2470) and for creatine was 2414 (95% CI, 2304-2524). The global statistical test yielded t1865.8 = -0.75 (2-sided P = .45). There were no detectable differences (P < .01 to partially adjust for multiple comparisons) in adverse and serious adverse events by body system.

CONCLUSIONS AND RELEVANCE

Among patients with early and treated Parkinson disease, treatment with creatine monohydrate for at least 5 years, compared with placebo did not improve clinical outcomes. These findings do not support the use of creatine monohydrate in patients with Parkinson disease.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00449865.

Balance and gait problems in the elderly

Gait and balance problems are common with advancing age. Disorders of balance and gait are particularly important in the elderly because they compromise independence and contribute to the risk of falls and injury. Although they are considered as separate clinical entities, balance and gait disturbance are often intertwined. Here, we discuss the principal anatomical and physiologic mechanisms responsible for balance and gait. We also review the different types of fall patterns commonly seen in subjects and a classification scheme for various gait disorders. Furthermore, we consider the relationship between balance and gait disorders and subcortical vascular disease. Potential interventions and therapies in those individuals with balance and gait disorders are also discussed.

Association of cumulative lead exposure with Parkinson's disease

BACKGROUND

Research using reconstructed exposure histories has suggested an association between heavy metal exposures, including lead, and Parkinson's disease (PD), but the only study that used bone lead, a biomarker of cumulative lead exposure, found a nonsignificant increase in risk of PD with increasing bone lead.

OBJECTIVES

We sought to assess the association between bone lead and PD.

METHODS

Bone lead concentrations were measured using 109Cd excited K-shell X-ray fluorescence from 330 PD patients (216 men, 114 women) and 308 controls (172 men, 136 women) recruited from four clinics for movement disorders and general-community cohorts. Adjusted odds ratios (ORs) for PD were calculated using logistic regression.

RESULTS

The average age of cases and controls at bone lead measurement was 67 (SD = 10) and 69 (SD = 9) years of age, respectively. In primary analyses of cases and controls recruited from the same groups, compared with the lowest quartile of tibia lead, the OR for PD in the highest quartile was 3.21 [95% confidence interval (CI), 1.17-8.83]. Results were similar but slightly weaker in analyses restricted to cases and controls recruited from the movement disorders clinics only (fourth-quartile OR = 2.57; 95% CI, 1.11-5.93) or when we included controls recruited from sites that did not also contribute cases (fourth-quartile OR = 1.91; 95% CI, 1.01-3.60). We found no association with patella bone lead.

CONCLUSIONS

These findings, using an objective biological marker of cumulative lead exposure among typical PD patients seen in our movement disorders clinics, strengthen the evidence that cumulative exposure to lead increases the risk of PD.

Psychogenic Gait Disorders

Psychogenic disorders of posture and gait are common and are the major manifestation in 8 to 10% of patients with psychogenic movement disorders. The colorful history of these disorders is reviewed. Anxiety and depression are the commonest psychological accompaniments of functional gait disorder in contemporary practice. The particular case of the cautious gait and its flip side, "fear of falling," are considered in more detail. Common presentations for somatoform disorders and malingering are also described. It is often possible to make this diagnosis based on recognition features and gait observation. Incongruous neurologic signs are commonly found, and several features are so typical as to be nearly diagnostic. Caveats and pitfalls in diagnosis based on observational features are noted. In particular, the cautious gait is often the presenting feature of an older patient with an organic balance impairment. An approach to the patient with psychogenic gait disorder is described. Although the nature of the problem is often quickly apparent in such patients, the optimal management is a challenge. Dramatic cures still occur, and some patients respond quickly to psychological management and rehabilitation therapies, but persistence for more than 6 to 12 months is frequently associated with an unfavorable prognosis and long-term disability. The outcome studies are reviewed.

Executive and emotional dysfunction in Machado-Joseph disease

Machado-Joseph disease (MJD) is an autosomal dominant spinocerebellar ataxia. Few studies have examined the neuropsychological and neurobehavioral profiles of patients with MJD. In this study, six individuals with MJD were given a battery of neuropsychological tests. Relative impairments on timed verbal attention tasks and verbal fluency (Stroop, Oral Symbol Digit Modalities, and Controlled Oral Word Association Test) were found. Other executive impairments also were seen on the Wisconsin Card Sorting Test, independent of motor dysfunction severity. Moderate- to severe levels of depressive symptoms were endorsed by four of the six patients, and caregivers observed increased apathy in the patients. Impaired executive and emotional functioning in MJD does not appear to be related to ataxia severity. These patients did not meet the criteria for dementia. General cognitive abilities, language, list learning, story recall, and untimed tasks of attention were within normal limits. Impaired executive abilities and emotional functioning in MJD patients is consistent with disruption of frontal-subcortical systems.

Neurologic disorders of gait

Gait disorders are important because of their prevalence, particularly among the elderly, and the associated risk of falls and injury. Neural networks that organize locomotion and maintain balance are briefly reviewed. Gait disorders can be classified based on observational features or by etiology. Several common disorders are discussed in more detail. Recent progress includes use of botulinum toxin for spastic gait in cerebral palsy, neurosurgical treatment of Parkinson's disease, and newer rehabilitation approaches to gait and balance training.

Experience With Transumbilical Breast Augmentation

Transumbilical breast augmentation (TUBA), an endoscopicassisted procedure in which saline breast prostheses are inserted through the umbilicus, is a patient-driven, frequently performed procedure that remains controversial. The author describes the operative technique and results in 90 patients who underwent TUBA between October 1996 and July 2000 by the same surgeon in a community practice. A total of 85 patients underwent submammary TUBA and 5 patients underwent submuscular TUBA. Seventy patients were available for follow-up. Postoperative results of the 70 patients were graded as very good in 56 (80%), good in 12 (17%), and fair in 2 (2.9%). Complications were conversion to an open approach in 1 patient and an accidental submuscular entry into the pocket in 1 patient. There were four capsular contractures (5.7%), 5 patients (7.1%) were reoperated: 2 for capsulectomies, 1 for implant buckling, 1 for scar revision, and 1 for removal of the implants. There were no implant ruptures, hematomas, or infections. Advantages of TUBA include minimal scarring, remote incision, short operating time, low capsular contracture rate, and rapid recovery. These results of this evolving procedure suggest that in select patients TUBA provides a high level of patient satisfaction and low complication rates. As TUBA techniques for submuscular placement continue to develop, more patients may become TUBA candidates.

Dystonia as a presenting feature of the 3243 mitochondrial DNA mutation

A variety of neurologic phenotypes have been described in patients with mitochondrial disorders. We report a 32-year-old man in whom dystonia was the salient and presenting feature of a mitochondrial DNA mutation. He presented at age 23 with writer's cramp and progressed over 5 years to exhibit dystonia in facial muscles and lower limbs. He also has exercise intolerance, mild, bilateral ptosis, proximal muscle weakness, and sensorineural hearing loss. Molecular genetic analysis of blood, urine, and muscle biopsy demonstrated the presence of a heteroplasmic point mutation at nucleotide position 3243. The 3243 mtDNA mutation has pleomorphic manifestations, and dystonia should be added to the list of associated clinical features.

Treatment of occupational cramp with botulinum toxin: diffusion of toxin to adjacent noninjected muscles

Over a 5-year period, 40 patients, 11 with musician's and 29 with writer's cramp, were treated with botulinum toxin A using a precise injection technique in which the hollow-bore electromyography (EMG) needle was positioned by both standard EMG and by muscle twitch evoked by stimulating current passed through it. Moderate to complete improvement in dystonia occurred in 28 patients (70%) after the first injection and in 34 patients (85%) after the second injection with better outcome in nonmusicians than in musicians. Of note, weakness of uninjected muscles, immediately adjacent to those injected, was found in 25/40 patients (63%). The most common patterns of toxin spread were from flexor digitorum sublimis to profundus, extensor carpi radialis to extensor digitorum communis, and extensor indicis proprius to extensor pollicis brevis. Spread to, and weakness of, adjacent uninjected muscles was a major factor contributing to suboptimal outcome in 6/39 (15%) such patients.

A familial factor independent of CAG repeat length influences age at onset of Machado-Joseph disease

Machado-Joseph disease (MJD) is a late-onset, progressive, neurodegenerative disorder caused by the expansion of an unstable trinucleotide (CAG) repeat sequence in a novel gene (MJD1) on chromosome 14. Previous studies showed that age at onset is negatively correlated with the number of CAG repeat units, but only part of the variation in onset age is explained by CAG repeat length. Ages at onset and CAG repeat lengths of 136 MJD patients from 23 kindreds of Portuguese descent were analyzed, to determine whether familial factors independent of CAG repeat length modulate age at onset of MJD. Correlation among sibs for onset age adjusted for CAG repeat length was .43, which indicates that an environmental or genetic factor common to sibs influences onset age. Positive correlations were also observed for avuncular (r = .22) and first-cousin pairs (r = .28), which supports the hypothesis that a genetic factor is influencing age at onset. Commingling analysis of onset ages adjusted for CAG repeat length identified three distributions in this population of affected individuals. Further studies of a much larger sample are needed to determine whether these distributions represent the influence of a genetic or environmental factor.

Frequency of spinocerebellar ataxia type 1, dentatorubropallidoluysian atrophy, and Machado-Joseph disease mutations in a large group of spinocerebellar ataxia patients

The spinocerebellar ataxias (SCAs) are a heterogeneous group of neurodegenerative disorders varying in both clinical manifestations and mode of inheritance. Six different genes causing autosomal dominant SCA are mapped: SCA1, SCA2, Machado-Joseph disease (MJD)/SCA3, SCA4, SCA5, and dentatorubropallidoluysian atrophy (DRPLA). Expansions of an unstable trinucleotide CAG repeat cause three of these disorders: SCA type 1 (SCA1), MJD, and DRPLA. We determine the frequency of the SCA1, DRPLA, and MJD mutations in a large group of unrelated SCA patients with various patterns of inheritance and different ethnic backgrounds. We studied 92 unrelated SCA patients. The frequency of the SCA1 mutation was 3% in the overall patient group and 10% in the non-Portuguese dominantly inherited SCA subgroup. We found that DRPLA mutation in only one Japanese patient, who was previously diagnosed with this disease. We identified the MJD mutation in 41% of the overall patient group, which included 38 autosomal dominant kindreds of Portuguese origin; the frequency of the MJD mutation among the non-Portuguese dominantly inherited cases was 17%. These results suggest that SCA may be occasionally caused by the SCA1 mutation and rarely caused by the DRPLA mutation and that, to date, the MJD mutation seems to be the most common cause of dominantly inherited SCA. Finally, our results suggest that recessively inherited cases of SCA are not caused by the known trinucleotide repeat expansions.

Correlation between CAG repeat length and clinical features in Machado-Joseph disease

Machado-Joseph disease (MJD) is associated with the expansion of a CAG trinucleotide repeat in a novel gene on 14q32.1. We confirmed the presence of this expansion in 156 MJD patients from 33 families of different geographic origins: 15 Portuguese Azorean, 2 Brazilian, and 16 North American of Portuguese Azorean descent. Normal chromosomes contain between 12 and 37 CAG repeats in the MJD gene, whereas MJD gene carriers have alleles within the expanded range of 62-84 CAG units. The distribution of expanded alleles and the gap between normal and expanded allele sizes is either inconsistent with a premutation hypothesis or most (if not all) of the alleles we studied descend from a common ancestor. There is a strong correlation between the expanded repeat size and the age at onset of the disease as well as the clinical presentation. There is mild instability of the CAG tract length with transmission of the expanded alleles; both increase and decrease in size between parents and progeny occur, with larger variations in male than in female transmissions. Together, these effects can partly explain the variability of age at onset and of phenotypic features in MJD; however, other modifying factors must exist.

Machado-Joseph disease

Machado-Joseph disease (MJD) is a form of dominantly-inherited ataxia originally described in people of Azorean and Portuguese descent. The disorder has subsequently been identified in Japan, Brazil, Australia, and China. Average age of onset is 35 to 40. Core features include progressive ataxia, dysarthria, postural instability, nystagmus, eyelid retraction, and facial fasciculations. Dystonia is often prominent in younger patients. Three distinct phenotypes appear to reflect the clinical spectrum of a single mutant gene. Neuropathology involves afferent and efferent cerebellar systems, with preservation of cerebellar cortex and inferior olive. Spinocerebellar pathways, substantia nigra, and cranial nerve motor nuclei are involved. The disorder is due to an unstable CAG repeat on chromosome 14q32.1. A dominantly inherited ataxia (SCA-3) in families of French and German descent has also been linked to this segment of chromosome 14. The relationship between MJD and the other dominant inherited ataxias is discussed.

Treatment of stiff-man syndrome with intravenous immune globulin

OBJECTIVE

To evaluate the efficacy of intravenous immune globulin (IVIG) in the treatment of stiff-man syndrome (SMS).

METHODS

An open, unblinded study of 3 patients with active disease and/or disease refractory to treatment with diazepam and/or corticosteroids.

RESULTS

All 3 bedridden patients improved substantially shortly after infusion with IVIG and regained function.

CONCLUSION

IVIG may be useful for the treatment of SMS.

Limb dystonia following electrical injury

Electrical injuries of the extremities may cause paralysis, muscle atrophy, sensory deficit, causalgia, and reflex sympathetic dystrophy (RSD). Limb dystonia has rarely been reported following electrical injury to an extremity, although it may result from cerebral hemisphere electrical trauma. Following electrical injury to the upper extremity, three patients developed limb dystonia accompanied by severe pain and sensory symptoms in two patients and features of RSD in one patient. Two patients received botulinum toxin injections without functional benefit. The mechanism of dystonia following peripheral trauma is unknown but may relate to reorganization of central synaptic connections, possibly in the spinal cord.

Machado-Joseph disease in New England: clinical description and distinction from the olivopontocerebellar atrophies

Experience is described in 25 patients from southern New England with Machado-Joseph Disease, examined serially at annual screening clinics. The disorder is dominantly inherited, with a wide range of phenotypic variation. Core clinical features described include ataxia, nystagmus, dysarthria, facial fasciculations, and lid retraction, producing a characteristic staring expression. In addition, young onset patients have spasticity, extrapyramidal rigidity, and dystonic manifestations. Late onset patients often have distal atrophy and sensory loss. Postural instability is often an early feature. We discuss the distinction of this entity from the olivopontocerebellar atrophies.

Dementia in Parkinson's disease: the problem of clinicopathological correlation

Four cases of Parkinson's disease with advanced dementia are described. Postmortem examination revealed cell loss in the substantia nigra, with Lewy bodies present, and loss of cells in the basal nucleus of Meynert. A few tangles were observed in the hippocampus, but no senile plaques or neurofibrillary tangles were found in the neocortex. The authors note that a dramatic dementia syndrome may occur with Parkinson's disease alone, without the associated cytoskeletal markers of Alzheimer's disease. Cases were characterized by disorientation, episodic confusion and hallucinations persisting off medication, disturbed behavior, and the absence of aphasia.

Gait failure

Gait failure is a common presentation in the Emergency Department, and one that may herald an acute neurologic episode. This article reviews the mechanisms of gait failure, some of their causes, and the appropriate examination techniques for determining possible diagnoses.

Sartorius muscle "twist" rotation flap: an answer to flap necrosis

Coverage of the femoral vessels with viable muscle flap after vascular reconstruction in the presence of infection is essential to prevent serious complications. Necrosis of the muscle flap as a result of interruption of its vascular pedicle can lead to complications that jeopardize the patient's life and limb. Our simple technique prevents such complications by preserving the muscle blood supply. We have used this method routinely during the past 6 years in patients with groin sepsis and did not encounter any case of muscle necrosis.

Gait disorder in late-life hydrocephalus

Computerized analysis of gait was performed in six patients with hydrocephalus (mean age, 75.7 years), for comparison with other elderly patients with gait problems and age-matched controls. A decrease in velocity and stride, an increase in sway, and the proportion of time spent in double-limb stance were nonspecific features correlated with declining performance. Certain features appeared to characterize hydrocephalic gait when compared among groups; cadence was diminished, and there was a reduction of step height and a decreased counterrotation of the shoulders relative to the pelvis. An abnormal tendency toward cocontraction in antagonist muscle groups was observed in electromyographic data from the leg muscles, suggesting that the normal phased activation of muscle groups is disturbed. Although data are not conclusive, we believe that the gait disorder in normal-pressure hydrocephalus reflects a subcortical motor control disorder rather than a phenomenon of spasticity or apraxia.

A single family with writer's cramp, essential tremor, and primary writing tremor

We studied seven members of a family who had different types of movement disorders: Two had typical essential tremor, two (twins) had typical writer's cramp, one had both essential tremor and writer's cramp, one had primary writing tremor, and one (deceased) had uncharacterized tremor. This appears to be the first report of writer's cramp in twins and in so many family members. This family links together primary writing tremor, essential tremor, and writer's cramp and may help resolve the apparent controversy about the relationship of primary writing tremor to essential tremor and writer's cramp.

Huntington's disease in monozygotic twins reared apart

Monozygotic twins, identical by serological studies, with Huntington's disease are described who were raised in separate households from birth. Age at onset, landmarks of the disease, and behavioural abnormalities were strikingly similar. Previously reported twin studies in Huntington's disease are reviewed. Twin data support the hypothesis that age at onset and several other clinical features of the illness are substantially determined by genetic mechanisms.

Gait disorders among elderly patients. A survey study of 50 patients

A series of 50 patients (mean age, 79.5 years) were examined for undiagnosed gait disorders. A single causal diagnosis was made in 56% (28) of the patients. Myelopathy from cervical spine disease was a common cause in 16% (eight patients). Eighteen percent (nine patients) had multiple sensory disorders. Sixteen percent (eight patients) had an idiopathic senile gait disorder, as defined by failure to establish other causes. Twenty-four percent (12 patients) had disorders for which effective primary therapy was available. As a group, patients with gait disorders had ventricular enlargement by computed tomography, when compared with age-matched controls.

Medial thalamic hemorrhage with amnesia

Three patients had amnesia and confusion as presenting features of thalamic hemorrhage. They had a relatively benign clinical appearance and lacked characteristics of the syndrome usually associated with thalamic hemorrhage. We reviewed hypotheses regarding a mechanism for the amnesic syndrome and concluded that lesions involving the medial thalamic nucleus were responsible for the amnesia observed.

Treatment of action tremor in multiple sclerosis with isoniazid

Four patients with disabling action tremor in the setting of MS were treated with isoniazid (800 to 1200 mg per day). All patients showed significant improvement of the tremor, allowing more functional use of their extremities. To the best of our knowledge, this is the only medical treatment for this type of tremor.

Effects of skim milk, whole milk and light cream on serum tryptophan binding and brain tryptophan concentrations in rats

One hour after rats fasted for 13 hours consume a single meal of skim milk, whole milk, or light cream, serum nonesterified fatty acid (NEFA) concentrations changed in direct proportion to the fat content of the diet: serum NEFA levels decreased in rats ingesting skim milk (0.09% fat) to 34% of fasting control values; in animals consuming whole milk (3.59% fat), levels dropped to 50% of fasting levels; these levels did not change significantly, however, in rats consuming light cream (18.26% fat). The percentages of total serum tryptophan not associated with albumin in rats ingesting skim milk, whole milk, or light cream were 22.2, 26.0, and 42.5%, respectively. These variations in serum free tryptophan were not accompanied by significant differences in brain tryptophan among the three treatment groups. These results thus confirm that, with a natural food source, (a) postprandial serum NEFA levels reflect the total fat content of the diet; (b) serum free tryptophan concentration shift proportionately with serum NEFA; and (c) serum free tryptophan concentrations do not reliably predict brain tryptophan levels.