Rigidity in Parkinson's disease: evidence from biomechanical and neurophysiological measures

Although rigidity is a cardinal motor sign in patients with Parkinson's disease (PD), the instrumental measurement of this clinical phenomenon is largely lacking, and its pathophysiological underpinning remains still unclear. Further advances in the field would require innovative methodological approaches able to measure parkinsonian rigidity objectively, discriminate the different biomechanical sources of muscle tone (neural or visco-elastic components), and finally clarify the contribution to 'objective rigidity' exerted by neurophysiological responses, which have previously been associated with this clinical sign (i.e. the long-latency stretch-induced reflex). Twenty patients with PD (67.3 ± 6.9 years) and 25 age- and sex-matched controls (66.9 ± 7.4 years) were recruited. Rigidity was measured clinically and through a robotic device. Participants underwent robot-assisted wrist extensions at seven different angular velocities randomly applied, when ON therapy. For each value of angular velocity, several biomechanical (i.e. elastic, viscous and neural components) and neurophysiological measures (i.e. short and long-latency reflex and shortening reaction) were synchronously assessed and correlated with the clinical score of rigidity (i.e. Unified Parkinson's Disease Rating Scale-part III, subitems for the upper limb). The biomechanical investigation allowed us to measure 'objective rigidity' in PD and estimate the neuronal source of this phenomenon. In patients, 'objective rigidity' progressively increased along with the rise of angular velocities during robot-assisted wrist extensions. The neurophysiological examination disclosed increased long-latency reflexes, but not short-latency reflexes nor shortening reaction, in PD compared with control subjects. Long-latency reflexes progressively increased according to angular velocities only in patients with PD. Lastly, specific biomechanical and neurophysiological abnormalities correlated with the clinical score of rigidity. 'Objective rigidity' in PD correlates with velocity-dependent abnormal neuronal activity. The observations overall (i.e. the velocity-dependent feature of biomechanical and neurophysiological measures of objective rigidity) would point to a putative subcortical network responsible for 'objective rigidity' in PD, which requires further investigation.

Gender differences in motor and non-motor symptoms in early Parkinson disease

Gender differences in motor and non-motor symptoms in Parkinson disease (PD) are still controversial. This study aimed to investigate gender differences in clinical characteristics in patients with early PD.This study included 415 PD patients (201 men and 214 women) with modified Hoehn-Yahr stage 1 to 3 and a disease duration of ≤5 years. Demographic information was obtained by interviews, and motor and non-motor PD symptoms were evaluated with appropriate scales.Women with PD had a shorter duration of formal education than men with PD. No significant differences were found in other demographic variables. Women with PD had significantly lower scores in Unified Parkinson Disease Rating Scale part III and postural tremor compared to men with PD, which was significant after controlling for formal education. No significant gender-related differences were found in scores related to other motor symptoms. Concerning non-motor symptoms, men with PD had higher scores of sexual function on the Non-Motor Symptoms Scale, which means sexual dysfunction was more severe or occurred more frequently in men with PD. Women with PD had significantly higher scores of sleep disturbance in the Pittsburgh Sleep Quality Index, which was not significant after adjustment for multiple comparison.The present study suggests that women with PD had milder motor symptoms compared to men with PD, and gender differences in sexual function can be observed as non-motor symptoms.

Efficacy of oral administration of licorice as an adjunct therapy on improving the symptoms of patients with Parkinson's disease, A randomized double blinded clinical trial

ETHNOPHARMACOLOGICAL RELEVANCE

Licorice preparations are used as neuroprotective remedies in Persian ethnomedicine, in order to prevent from disabilities in neurodegenerative conditions like Parkinson's disease (PD).

AIM OF THE STUDY

This study was designed to determine the licorice (root of Glycyrrhiza glabra L.) effectiveness as an adjunct treatment in the PD management.

MATERIAL AND METHODS

In this double-blinded trial, 128 patients were assessed for eligibility criteria. Seventy-eight patients were ineligible and 11 of them refused from participating. Thirty-nine PD patients (YAHR staging ≤ 3) were divided into two groups by random. The patients received oral licorice or placebo syrups with a dose of 5 cc, twice a day for 6 months. High-performance liquid chromatography and spectrophotometric instruments determined licorice syrup constituents. The patients' situation for Unified Parkinson's rating scale (UPDRS) was assessed every 6 weeks for the duration of six months. In addition, patients' blood pressure, blood glucose, sodium and potassium levels, quality of life and dizziness were determined.

RESULTS

Six weeks after intervention, total UPDRS, daily activities and tremor were significantly improved with a considerable effect size. A significant better motor test and rigidity scores were observed 4 months after licorice intake (p > 0.05). No electrolyte abnormality, significant changes in blood pressure or blood glucose levels were observed during the study. Each 5cc of syrup contained 136 mg of licorice extract with 12.14 mg glycyrrhizic acid, and also 136 μg of polyphenols.

CONCLUSION

The licorice intake could improve the symptoms in PD patients without serious adverse events.

Electrophysiological resting state networks of predominantly akinetic-rigid Parkinson patients: Effects of dopamine therapy

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Analysis of whole-brain frequency-specific resting state networks with EEG.

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Comparison of dopamine medication ON and OFF state in Parkinson patients.

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Parkinson patients show distinct frequency-specific network alterations.

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Motor network at beta frequencies is re-instated after dopamine medication.

Parkinson's disease (PD) causes both motor and non-motor symptoms, which can partially be reversed by dopamine therapy. These symptoms as well as the effect of dopamine may be explained by distinct alterations in whole-brain architecture. We used functional connectivity (FC) and in particular resting state network (RSN) analysis to identify such whole-brain alterations in a frequency-specific manner. In addition, we hypothesized that standard dopaminergic medication would have a normalizing effect on these whole brain alterations. We recorded resting-state EEGs of 19 PD patients in the medical OFF and ON states, and of 12 healthy age-matched controls. The PD patients were either of akinetic-rigid or mixed subtype. We extracted RSNs with independent component analysis in the source space for five frequency bands. Within the sensorimotor network (SMN) the supplementary motor area (SMA) showed decreased FC in the OFF state compared to healthy controls. This finding was reversed after dopamine administration. Furthermore, in the OFF state no stable SMN beta component could be identified. The default mode network showed alterations due to PD independent of the medication state. The visual network was altered in the OFF state, and reinstated to a pattern similar to healthy controls by medication. In conclusion, PD causes distinct RSN alterations, which are partly reversed after levodopa administration. The changes within the SMN are of particular interest, because they broaden the pathophysiological understanding of PD. Our results identify the SMA as a central network hub affected in PD and a crucial effector of dopamine therapy.

Stiff limb syndrome with lower limb myoclonus: A case report

RATIONALE

stiff limb syndrome (SLS) is a variant of stiff-man syndrome, primarily affecting a specific limb. Its diagnosis has always been challenging due to the lack of a specific confirmation test. We present a rare case of a patient with lower limb myoclonus and rigidity.

PATIENT CONCERNS

A 53-year-old male presented with a sudden onset of progressive left lower extremity myoclonus and muscle rigidity for 3 days. He rapidly showed signs of right lower limb involvement with severe joint stiffness and inability to walk.

DIAGNOSIS

The symptoms nature, physical examination, careful elimination of differential diagnosis suggested a diagnosis of stiff limb syndrome.

INTERVENTIONS

Intravenous infusion of gamma globulin 0.4 mg/kg coupled with baclofen and clonazepam were given after admission. He also received an injection of botulinum toxin A to relieve his muscle stiffness.

OUTCOMES

The patients' condition improved after the initial treatment with complete disappearance of muscle twitching. Further improvements were seen later on after the local administration of botulinum toxin A.

LESSONS

Stiff limb syndrome shares the same complex symptoms with many other conditions. Its diagnosis relies heavily on clinical presentations and on ruling out other conditions. However, unusual symptoms such as myoclonus can occur in few cases and together with the rarity of the condition, the prevalence of misdiagnosis is high. Therefore, being aware and recognizing the signs and symptoms is crucial for proper management. Additionally, EMG is a very important test if the present condition is suspected. However, a negative EMG result or a negative anti-glutamic acid decarboxylase antibody test should not exclude SLS diagnosis.

How different aspects of motor dysfunction influence day-to-day function in huntington's disease

PURPOSE

This study examined the relationships between different aspects of motor dysfunction (chorea, dystonia, rigidity, incoordination, oculomotor dysfunction, dysarthria, and gait difficulties) and functional status in persons with Huntington's disease.

METHODS

A total of 527 persons with Huntington's disease completed the Unified Huntington's Disease Rating Scale motor, total functional capacity, and functional assessments.

RESULTS

Confirmatory factor analysis indicated that a 4-factor model provided a better model fit than the existing 5-factor model. Exploratory factor analysis identified the following 4 factors from the motor scale: dystonia, chorea, rigidity, and a general motor factor. Regression indicated that dystonia (β = -0.47 and -0.79) and rigidity (β = -0.28 and -0.59) had strong associations with function, whereas chorea had modest correlations (β = -0.16 and -0.15).

CONCLUSIONS

Dystonia and rigidity have stronger relationships with functional status than chorea in persons with Huntington's disease. The findings underscore the need for further research regarding the effects of dystonia and rigidity on functioning. © 2019 International Parkinson and Movement Disorder Society.

Washout of chronic therapeutic deep brain stimulation increases cortical phase-amplitude coupling

Invasive human brain recordings have shown that acute therapeutic deep brain stimulation (DBS) reduces cortical synchronization, measured by coupling of beta phase to gamma amplitude. Here we show by noninvasive scalp electroencephalography that withdrawal of chronic DBS elevates phase-amplitude coupling, in proportion to the worsening of contralateral rigidity.

Giant Cell Arteritis: 2018 Review

Giant cell arteritis is the most common large vessel vasculitis. Classic symptoms include headaches, scalp tenderness, visual loss and muscle stiffness and pain. First line treatment is with high dose steroids but methotrexate may be of some help in decreasing steroid use. Tocilizumab has been shown to significantly decrease relapse rate and lower steroid cumulative dose.

The long-term efficacy of STN vs GPi deep brain stimulation for Parkinson disease: A meta-analysis

OBJECTIVE

This meta-analysis assessed the long-term efficacy of deep brain stimulation (DBS) of the subthalamic nucleus (STN) and globus pallidus interna (GPi) for Parkinson disease (PD).

METHODS

PubMed, Cochrane Library, and Clinical Trials databases were searched. Outcomes were unified Parkinson disease rating scale section (UPDRS) III off-medication score, Parkinson's disease questionnaire: 39 activities of daily living (PDQ-39 ADL) score, and levodopa-equivalent dosage after DBS.

RESULTS

During the off-medication state, pooled weighted mean difference (WMD) of UPDRS III score was .69 (95% confidence interval [CI] = -1.77 to 3.16, P = .58). In subgroup analysis, WMD of UPDRS III off-medication scores from baseline to 2 years and 3 years post-DBS were -.61 (95% CI = -2.97 to 1.75, P = .61) and 2.59 (95% CI = -2.30 to 7.47, P = .30). Pooled WMD of changes in tremor, rigidity, and gait scores were 1.12 (95% CI = -0.05 to 2.28, P = .06), 1.22 (95% CI = -0.51 to 2.94, P = .17) and .37 (95% CI = -0.13 to 0.87, P = .15), respectively. After DBS, pooled WMD of PDQ-39 ADL and LED were -3.36 (95% CI = -6.36 to -0.36, P = .03) and 194.89 (95% CI = 113.16 to 276.63, P < .001).

CONCLUSIONS

STN-DBS and GPi-DBS improve motor function and activities of daily living for PD. Differences in the long-term efficacy for PD on motor symptoms were not observed.

Muscular MRI-based algorithm to differentiate inherited myopathies presenting with spinal rigidity

OBJECTIVES

Inherited myopathies are major causes of muscle atrophy and are often characterized by rigid spine syndrome, a clinical feature designating patients with early spinal contractures. We aim to present a decision algorithm based on muscular whole body magnetic resonance imaging (mWB-MRI) as a unique tool to orientate the diagnosis of each inherited myopathy long before the genetically confirmed diagnosis.

METHODS

This multicentre retrospective study enrolled 79 patients from referral centres in France, Brazil and Chile. The patients underwent 1.5-T or 3-T mWB-MRI. The protocol comprised STIR and T1 sequences in axial and coronal planes, from head to toe. All images were analyzed manually by multiple raters. Fatty muscle replacement was evaluated on mWB-MRI using both the Mercuri scale and statistical comparison based on the percentage of affected muscle.

RESULTS

Between February 2005 and December 2015, 76 patients with genetically confirmed inherited myopathy were included. They were affected by Pompe disease or harbored mutations in RYR1, Collagen VI, LMNA, SEPN1, LAMA2 and MYH7 genes. Each myopathy had a specific pattern of affected muscles recognizable on mWB-MRI. This allowed us to create a novel decision algorithm for patients with rigid spine syndrome by segregating these signs. This algorithm was validated by five external evaluators on a cohort of seven patients with a diagnostic accuracy of 94.3% compared with the genetic diagnosis.

CONCLUSION

We provide a novel decision algorithm based on muscle fat replacement graded on mWB-MRI that allows diagnosis and differentiation of inherited myopathies presenting with spinal rigidity.

KEY POINTS

• Inherited myopathies are rare, diagnosis is challenging and genetic tests require specialized centres and often take years. • Inherited myopathies are often characterized by spinal rigidity. • Whole body magnetic resonance imaging is a unique tool to orientate the diagnosis of each inherited myopathy presenting with spinal rigidity. • Each inherited myopathy in this study has a specific pattern of affected muscles that orientate diagnosis. • A novel MRI-based algorithm, usable by every radiologist, can help the early diagnosis of these myopathies.

[Translation and validation of the Individualised Neuromuscular Quality of Life scale for the Spanish population: quality of life assessment for persons with neuromuscular diseases]

INTRODUCTION

The Individualized Neuromuscular Quality of Life (INQoL) is a questionnaire that evaluates the quality of life related to the health of adults with neuromuscular diseases.

AIM

To validate and analyze the reliability of the Spanish version of the INQoL scale as an instrument for measuring quality of life related to health in individuals with neuromuscular diseases.

PATIENTS AND METHODS

A translation-back translation of the INQoL in the Spanish population is performed and, subsequently, for the analysis of reliability, two measurements are carried out; test retest, with 50 patients aged between 19 and 67 years. In this way we assess the intraobserver concordance and assess the internal consistency of the scale.

RESULTS

The study of the reliability of the intraobserver concordance index has a value of excellent in seven of the ten subdimensions as well as in the total score of the quality of life. It has a value of good in two and of moderate in one subdimension. The analysis of Cronbach's alpha for the subdimensions of the INQoL has a value of excellent (> 0.818) in seven of them, as well as in the total score of the quality of life related to health (0.928), a value of good internal consistency in three of the subdimensions, and of moderate in one.

CONCLUSIONS

The Spanish version of the INQoL is a valid and reliable instrument as a tool for measuring quality of life in adult patients with neuromuscular diseases.

The Motor Syndrome of Parkinson's Disease

The clinical diagnosis of Parkinson's disease (PD) is centered on a specific motor syndrome that is characterized by the presence of bradykinesia, plus rest tremor, muscle rigidity, or both. Recently, novel criteria for diagnosing PD have been released that rehearse the motor syndrome as the core feature of PD. Beyond these three main symptoms, other motor features might be present in PD including gait difficulties and postural instability. Moreover, patients with PD usually develop motor complications 5-10 years into their disease. These motor complications are the strongest predictor of PD pathology and are in fact used clinically to support the diagnosis. Ancillary investigations are usually of little utility and to perform only in selected cases, which remarks the importance of the clinical examination for making the diagnosis of PD or suspect other condition that can be masquerading it.

Quantification of neural reflex and muscular intrinsic contributions to parkinsonian rigidity

Parkinson's disease (PD) is a progressive neurodegenerative disease characterized by rigidity, bradykinesia, resting tremor, and postural instability. Rigidity, defined as an increased resistance to passive movement of a joint, progresses faster than other motor signs in PD. Rigidity is attributable to both exaggerated neural reflex and altered muscle mechanical properties. However, little is known about the contributions of individual components to rigidity. Further, there is no evidence regarding the effects of dopaminergic medication on individual components. Objectives of this study were to quantify the contributions of neural reflexes and intrinsic muscle properties to rigidity and investigate the effects of medication on each contributing component. Joint torque and muscle activities of the wrist in 14 patients and 14 controls were measured during externally induced movements. Each subject with PD was tested in Off- and On-medication states. A system identification technique was applied to differentiate and quantify the neural reflex and intrinsic mechanical components. A mixed model of ANOVA was performed to compare the differences between the two components of rigidity for both groups, and to compare between the Off- and On-medication states for patients. The results showed that reflex and intrinsic components are comparable (p > 0.05), and both are enhanced in subjects with PD than in the controls (p < 0.05). Medication decreased the reflex component of rigidity (p < 0.01). It is concluded that both reflex and intrinsic factors are responsible for rigidity. Present findings are clinically significant as they may provide guidance in development of effective therapeutic interventions.

Two Cases of Tetanus?

Tetanus is a rare infectious disease in Western countries that leads to diagnostic difficulties. Several diseases may mimic tetanus, and diagnostic considerations can at times be difficult, especially in critically ill patients, who need prompt treatment. Two patients are presented who were diagnosed with and treated for tetanus. However, the course of these patients’ diseases strongly suggested that the diagnoses were incorrect. The article includes reflections on these 2 difficult diagnostic cases. These 2 cases illustrate the importance of proposing alternative diagnoses in suspected tetanus in Western countries. This may prevent loss of valuable time and prevent a delay of possibly effective therapy.

Early-onset Parkinson's Disease Associated with Chromosome 22q11.2 Deletion Syndrome

We herein report the case of a 43-year-old man with a 4-year history of resting tremor and akinesia. His resting tremor and rigidity were more prominent on the left side. He also presented retropulsion. His symptoms responded to the administration of levodopa. The patient also had a cleft lip and palate, cavum vergae, and hypoparathyroidism. A chromosome analysis disclosed a hemizygous deletion in 22q11.2, and he was diagnosed with early-onset Parkinson's disease associated with 22q11.2 deletion syndrome. However, the patient lacked autonomic nerve dysfunction, and his cardiac uptake of (123)I-metaiodobenzylguanidine was normal, indicating an underlying pathological mechanism that differed to that of sporadic Parkinson's disease.

Pattern of extrapyramidal signs in Alzheimer's disease

Patients with Alzheimer's disease (AD) often develop extrapyramidal signs (EPS), which increase in frequency as the disease progresses. We aimed to investigate the patterns of presentation of EPS in AD and their correlation with clinical and neuropathological features. 4284 subjects diagnosed with AD from the National Alzheimer's Coordinating Center (NACC) database with at least one abnormal Unified Parkinson's Disease Rating Scale (UPDRS) assessment were included. Individuals were assigned to a discovery sample and a sensitivity analysis sample (moderate and mild dementia, respectively) and a subset of subjects provided neuropathological data (n = 284). Individuals from the Washington Heights and Inwood Columbia Aging Project (WHICAP) served as validation sample. Patterns of presentation of EPS were identified employing categorical principal component analysis (CATPCA). Six principal components were identified in both mild and moderate AD samples: (I) hand movements, alternating movements, finger tapping, leg agility ("limbs bradykinesia"); (II) posture, postural instability, arising from chair, gait and body bradykinesia/hypokinesia ("axial"); (III) limb rigidity ("rigidity"); (IV) postural tremor; (V) resting tremor; (VI) speech and facial expression. Similar results were obtained in the WHICAP cohort. Individuals with hallucinations, apathy, aberrant night behaviors and more severe dementia showed higher axial and limb bradykinesia scores. "Limb bradykinesia" component was associated with a neuropathological diagnosis of Lewy body disease and "axial" component with reduced AD-type pathology. Patterns of EPS in AD show distinct clinical and neuropathological correlates; they share a pattern of presentation similar to that seen in Parkinson's disease, suggesting common pathogenic mechanisms across neurodegenerative diseases.

GAD Antibodies as Key Link Between Chronic Intestinal Pseudoobstruction, Autonomic Neuropathy, and Limb Stiffness in a Nondiabetic Patient: A CARE-Compliant Case Report and Review of the Literature

Chronic intestinal pseudoobstruction (CIP) can be a severe burden and even a life-threatening disorder. Typically, several years of uncertainty are passing before diagnosis. We are reporting the case of a young woman with a decade of severe, progressive gastrointestinal dysmotility. Unusually, she had also developed an autonomic neuropathy, and a stiff limb syndrome.In addition to achalasia and CIP the young woman also developed neuropathic symptoms: orthostatic intolerance, urinary retention, a Horner syndrome, and lower limb stiffness. Careful interdisciplinary diagnostics excluded underlying infectious, rheumatoid, metabolic or tumorous diseases.The detection of GAD (glutamic acid decarboxylase) antibodies, however, seemed to link CIP, autonomic neuropathy, and limb stiffness and pointed at an autoimmune origin of our patient's complaints. This was supported by the positive effects of intravenous immunoglobulin. In response to this therapy the body weight had stabilized, orthostatic tolerance had improved, and limb stiffness was reversed.The case suggested that GAD antibodies should be considered in CIP also in nondiabetic patients. This may support earlier diagnosis and immunotherapy.

Stiff Person Syndrome

Stiff-person syndrome or Moersch-Woltmann is a very rare and disabling neurologic disorder characterized by muscle rigidity and episodic spasms involving axial and limb musculature. It is an autoimmune disorder resulting in a malfunction of aminobutyric acid mediated inhibitory networks in the central nervous system. We describe a patient of stiff person syndrome.

[A case of progressive encephalomyelitis with rigidity and myoclonus associated with anti-GAD, anti-glycine receptor and anti-GM1 antibodies]

A 62-year-old woman with one-year history of type 1 diabetes mellitus was admitted to our hospital with progressive weakness in the lower extremities and urinary dysfunction following high fever. On admission, she had rigidity and myoclonus in the upper extremities with sensory ataxia. Cerebrospinal fluid examination revealed mild pleocytosis and oligoclonal band. Glutamic acid decarboxylase (GAD) antibodies were detected at high titer in serum, but antibodies to glycine receptor (GlyR), thyroid peroxidase, mitochondrial M2, and GM1 were also detected. She was diagnosed with progressive encephalomyelitis with rigidity and myoclonus (PERM), which probably developed on the basis of polyglandular autoimmune syndromes. The clinical symptoms began to improve after initiation of intravenous high-dose methylprednisolone. Muscle weakness might be related to GM1 antibodies. This is the first report of PERM, in which GM1 antibodies were detected with GAD and GlyR antibodies.

Parkinsonian syndromes

PURPOSE OF REVIEW

The different parkinsonian conditions can be challenging to separate clinically. This review highlights the important clinical features that guide the diagnosis of Parkinson disease (PD), progressive supranuclear palsy (PSP), multiple system atrophy (MSA), and corticobasal degeneration (CBD). Strategies for treatment and disease management are also discussed.

RECENT FINDINGS

Over the past decade there has been an increasing recognition of the broad clinical presentations of the neurodegenerative forms of parkinsonism. Nonmotor symptoms in these diseases, including psychiatric, cognitive, autonomic, and gastrointestinal dysfunction, appear to have a major impact on quality of life and disability. PSP and CBD are now considered pathologic diagnoses, with several different and varied clinical phenotypes, that overlap and share features with PD and frontotemporal dementia syndromes. PD is distinguished by its excellent response to dopaminergic medications that is maintained over many years, in contrast to the response seen in patients with MSA and PSP. New diagnostic criteria have been proposed for CBD. No new therapeutic interventions have emerged for PSP, MSA, or CBD. Infusional therapies and deep brain stimulation surgery are established therapies for advanced PD.

SUMMARY

The "parkinsonian syndromes" encompass a number of nosologic entities that are grouped together on the basis of their shared clinical features but are separated on the basis of their different pathologies. Overall, the consideration of clinical signs, mode of disease onset, and nature of disease progression are all important to make a timely and definitive diagnosis.

Parkinsonian features in hereditary diffuse leukoencephalopathy with spheroids (HDLS) and CSF1R mutations

Atypical Parkinsonism associated with white matter pathology has been described in cerebrovascular diseases, mitochondrial cytopathies, osmotic demyelinating disorders, leukoencephalopathies leukodystrophies, and others. Hereditary diffuse leukoencephalopathy with spheroids (HDLS) is an autosomal dominant disorder with symptomatic onset in midlife and death within a few years after symptom onset. Neuroimaging reveals cerebral white matter lesions that are pathologically characterized by non-inflammatory myelin loss, reactive astrocytosis, and axonal spheroids. Most cases are caused by mutations in the colony-stimulating factor 1 receptor (CSF1R) gene. We studied neuropathologically verified HDLS patients with CSF1R mutations to assess parkinsonian features. Ten families were evaluated with 16 affected individuals. During the course of the illness, all patients had at least some degree of bradykinesia. Fifteen patients had postural instability, and seven had rigidity. Two patients initially presented with parkinsonian gait and asymmetrical bradykinesia. These two patients and two others exhibited bradykinesia, rigidity, postural instability, and tremor (two with resting) early in the course of the illness. Levodopa/carbidopa therapy in these four patients provided no benefit, and the remaining 12 patients were not treated. The mean age of onset for all patients was about 45 years (range, 18-71) and the mean disease duration was approximately six years (range, 3-11). We also reviewed HDLS patients published prior to the CSF1R discovery for the presence of parkinsonian features. Out of 50 patients, 37 had gait impairments, 8 rigidity, 7 bradykinesia, and 5 resting tremor. Our report emphasizes the presence of atypical Parkinsonism in HDLS due to CSF1R mutations.

Segmental progression of cardinal motor symptoms in Parkinson's disease: a pilot study suggesting a practical approach to rate disease course in the early stages

Little is known about the anatomical progression over the body segments of extrapyramidal signs in Parkinson's disease (PD); furthermore a great unmet need is the availability of instruments able to detect disease progression, even in the early phase. The purpose of this study is to demonstrate that assessing topographical distribution of the cardinal motor features of PD may significantly improve the evaluation of disease progression in the early stages. Forty-four drug-naïve PD patients were included in the study. Presence or absence of bradykinesia, rest tremor and rigidity was derived from Unified Parkinson's disease rating scale part III (UPDRS-III) in five different anatomical segments: axial, right and left upper- and lower-limbs. Based on this approach, four new scores were computed evaluating the anatomical spread of the cardinal motor symptoms of PD on the five body segments over a 18-month follow-up period. The four new scores included: the Bradykinesia Segmental Score, the Tremor Segmental Score, the Rigidity Segmental Score, measuring the occurrence of each motor symptom in different segments and the Combined Segmental Score evaluating the occurrence of any motor symptom in different anatomical regions. Data were analyzed using a repeated measures analysis of variance. The Combined Segmental Score showed a significant progression over time whereas the Hoehn and Yahr and the UPDRS-III scores did not. We suggest that a simple approach evaluating the anatomical distribution of motor symptoms and their progression over the body segments may be a useful complement to the classical rating tools to assess progression in early PD.

Influence of BDNF polymorphisms on Wilson's disease susceptibility and clinical course

Susceptibility to Wilson's disease (WD) and its clinical manifestations are thought to be affected by genetic factors, including polymorphisms. The role of brain-derived neurotrophic factor (BDNF) in the pathogenesis of neurodegenerative diseases is now widely discussed. The aim of the present study was to evaluate the frequency of the BDNF Val66Met (G-196A) and C-270T polymorphisms in WD patients and in healthy controls, and to determine the role of these polymorphisms in the clinical characteristics of WD. We found that the BDNF Val/Val (-196 G/G) and -270 C/T genotypes occurred more frequently in WD patients than in healthy controls (66 % versus 45.5 %, p = 0.0001, and 14 % versus 6 %, p = 0.018, respectively). Similarly, symptomatic patients carried the BDNF Val/Val genotype more often than presymptomatic patients (75 % versus 53 %, p = 0.0097). No association was detected between any of the determined polymorphisms and the dominant form of the disease or the age of onset for WD.

Neck rigidity as a physical manifestation of higher brain hypo-function/dysfunction

A total of 308 patients, who received inpatient rehabilitation in department of Neurology in Sapporo City General Hospital, were studied. The patients were divided into four subgroups according to the presence or absence of Parkinsonism and the location of organic neurological lesions: group A consisted of 47 patients with brain lesions who presented with Parkinsonism; group B consisted of 135 patients with manifestations deriving from brain disorders other than Parkinsonism; group C consisted of 68 patients with manifestations deriving from spinal cord, peripheral nerve, and muscle disorders; and group D consisted of 58 patients with non-organic functional disorders and patients with organic lesions not responsible for clinical manifestations. The patients were administered a battery of 5 tests for evaluating frontal lobe and/or higher brain function. In result, our study confirmed higher brain/frontal lobe dysfunction to affect the grade of neck rigidity unless there is an interruption, in the control of peripheral organs, by the brain. Consequently the association between higher brain/frontal lobe dysfunction and the grade of neck rigidity were confirmed. Although neck rigidity may be a minor clinical manifestation, it can provide important clues to brain function.

Enhancement of parkinsonian rigidity with contralateral hand activation

OBJECTIVE

Quantify the enhancement of parkinsonian rigidity associated with a contralateral activation maneuver.

METHODS

Twelve subjects with PD and eight controls participated in the study protocol. Subjects' tested hand was displaced by a servo-motor throughout wrist flexion and extension motions of 60° without and with a concurrent gripping activation in the contralateral hand, referred to as Passive and Active conditions, respectively. Subjects with PD were tested in both OFF-MED and ON-MED states. Rigidity was quantified by integrating torque with position during both flexion and extension (torque resistance). ANOVA was performed to assess the effect of contralateral activation on rigidity.

RESULTS

PD patients had significantly (0.038) enhanced torque resistance in OFF-MED compared to healthy controls and ON-MED. In the Active condition, differences in torque resistance were magnified (p=0.002). Medication substantially reduced differences in torque resistance between controls and PD patients in the Passive and Active conditions.

CONCLUSIONS

A contralateral activation maneuver substantially increases rigidity in patients with PD, specifically the OFF-MED state. Rigidity is reduced with the application of dopaminergic medication, even with the presence of a contralateral activation maneuver.

SIGNIFICANCE

These data support the use of a contralateral activation maneuver as a tool in the diagnosis of PD.

Differential involvement of striato- and cerebello-thalamo-cortical pathways in tremor- and akinetic/rigid-predominant Parkinson's disease

Parkinson's disease (PD) presents clinically with varying degrees of resting tremor, rigidity, and bradykinesia. For decades, striatal-thalamo-cortical (STC) dysfunction has been implied in bradykinesia and rigidity, but does not explain resting tremor in PD. To understand the roles of cerebello-thalamo-cortical (CTC) and STC circuits in the pathophysiology of the heterogeneous clinical presentation of PD, we collected functional magnetic resonance imaging (fMRI) data from 17 right-handed PD patients [nine tremor predominant (PDT) and eight akinetic-rigidity predominant (PDAR)] and 14 right-handed controls while they performed internally-guided (IG) sequential finger tapping tasks. The percentage of voxels activated in regions constituting the STC and CTC [divided as cerebellar hemisphere-thalamo-cortical (CHTC) and vermis-thalamo-cortical (CVTC)] circuits was calculated. Multivariate analysis of variance compared the activation patterns of these circuits between study groups. Compared to controls, both PDAR and PDT subjects displayed an overall increase in the percentage of voxels activated in both STC and CTC circuits. These increases reached statistical significance in contralateral STC and CTC circuits for PDT subjects, and in contralateral CTC pathways for PDAR subjects. Comparison of PDAR and PDT subjects revealed significant differences in ipsilateral STC (P=0.005) and CTC (P=0.043 for CHTC and P=0.003 for CVTC) circuits. These data support the differential involvement of STC and CTC circuits in PD subtypes, and help explain the heterogeneous presentation of PD symptoms. These findings underscore the importance of integrating CTC circuits in understanding PD and other disorders of the basal ganglia.

[Quantitative measurement of axial rigidity, functional status and health-related quality of life in patients with Parkinson's disease]

INTRODUCTION

Rigidity is a cardinal symptom of Parkinson's disease (PD). Clinically, rigidity is usually assessed by passively flexing and extending a patient's limb. Few studies have assessed rigidity in trunk muscles in PD patients.

AIMS

To develop an objective measurement to quantify trunk rigidity in PD patients, and to examine its relationship with disease severity using the Hoehn and Yahr staging score (HY) and the Unified Parkinson's Disease Rating Scale III (UPDRS-III), disease duration, functional status with the Schwab & England activities of daily living scale and health related quality of life (HRQoL) was assessed with the European Quality of Life-5 Dimensions and Parkinson's Disease Questionnaire-39 items (PDQ-39).

PATIENTS AND METHODS

An isokinetic dynamometer Biodex System 3 was employed to assess trunk rigidity in 36 PD patients. Passive trunk flexion and extension at 3 angular velocities, 30 degrees/s, 45 degrees/s and 60 degrees /s were applied and resistive torques were recorded as trunk flexor and extensors rigidity.

RESULTS

Significant correlations between trunk flexors-extensors tone and HY staging score, UPDRS-III, disease duration and functional status at 30 degrees/s, 45 degrees/s and 60 degrees/s were obtained. Trunk rigidity was correlated with the HRQoL assessed with the PDQ-39.

CONCLUSIONS

Our results suggest that the 30 degrees/s, 45 degrees/s and 60 degrees/s angular velocities of this objective method was valid to assess trunk rigidity and was correlated with disease severity, disease duration, functional status and HRQoL in PD patients.

Neurotoxic manifestations of an overdose intrathecal injection of gadopentetate dimeglumine

The intravenous administration of gadopentetate dimeglumine (GD) is relatively safe and rarely causes systemic toxicity in the course of routine imaging studies. However, the general safety of intrathecal GD has not been established. We report a very rare case of an overdose intrathecal GD injection presenting with neurotoxic manifestations, including a decreased level of consciousness, global aphasia, rigidity, and visual disturbance.

Pseudomeningeal syndrome of Dupre associated with cervical discopathy--case report

BACKGROUND AND PURPOSE

The below publication presents a case of a 51-year-old patient with cervical discopathy of unusual clinical course.

CASE REPORT

The symptoms of the disease suddenly became aggravated and took a form of meningeal syndrome without inflammation of cerebrospinal fluid. The authors emphasize the symptomatology and diagnostic difficulties connected to unusual clinical course of cervical discopathy at the level of VC3/VC4.

DISCUSSION

Both medical and neurosurgical approaches to clinical history of cervical discopathic patient were presented in details. The patient underwent anterior cervical interbody fusion and the operative procedure was very effective for a few years up till now.

Efficacy and tolerability of eperisone in patients with spastic palsy: a cross-over, placebo-controlled dose-ranging trial

BACKGROUND AND OBJECTIVES

Central muscle relaxants are a clinical option in patients with spastic palsy. Eperisone is a central muscle relaxant used in several conditions, but its therapeutic potential in spastic palsy needs to be verified. This dose-ranging trial compares two doses of eperisone in patients with spastic palsy associated to cerebral or spinal diseases.

PATIENTS AND METHODS

In this randomized, placebo-controlled, double-blind, three-way cross-over study, patients (18-75 years) with spastic palsy received eperisone 150 mg/day, eperisone 300 mg/day, or placebo for 8 weeks. Treatment periods lasted for 14 days. Objective clinical parameters (intensity of spasticity and physiological reflexes) and functional parameters (walking capability, capability to climb stairs, rigidity) were measured. Tolerability was also evaluated.

RESULTS

Eighteen patients were enrolled. The reduction in the intensity of spasticity versus the beginning of each treatment cycle was significant with eperisone 300 mg/day (p = 0.004). Similar findings were observed in the evaluation of patellar reflex (p = 0.01), while the other reflexes were not significantly different. Walking capability was significantly improved with eperisone 300 mg/day (p < 0.05). No significant differences were observed in the capability to climb stairs and in rigidity. A trend towards a reduction in pain was noted with eperisone 300 mg/day versus placebo. The incidence of adverse events was similar in all groups.

DISCUSSION

Eperisone 300 mg/day might be an effective and well-tolerated treatment for spastic palsy. Larger studies are required to further characterize the efficacy of eperisone in this therapeutic area.

[Anesthesia considerations for deep-brain stimulation in a patient with type-2 pantothenate kinase deficiency (Hallervorden-Spatz disease)]

Neurodegeneration associated with pantothenate kinase deficiency is an autosomal recessive condition caused by mutations in the pantothenate kinase 2 gene (PANK2). Clinical characteristics include progressive motor impairment and dementia. Medical treatment is limited and the dystonia tends to be refractory, making stereotactic surgery with placement of deep-brain electrodes an option that is being adopted with greater frequency in these patients. We report the case of a 32-year-old woman with severe dystonia associated with PANK2 protein deficiency. The patient was scheduled for stereotactic bilateral placement of electrodes in the medial globus pallidus, guided by computed tomography and under general anesthesia, to treat the debilitating dystonia and generalized stiffness associated with her condition. Anesthesia was maintained with propofol, rocuronium and remifentanil in perfusion during the intervention, which was uneventful. After the procedure, the patient was transferred to the intensive care unit and sedation was provided with remifentanil to allow slow, gradual emergence from anesthesia. The patient was discharged from hospital after placement of the implanted pulse generator, and subsequent follow-up showed improvement of the dystonia.

Mokken scale analysis of the UPDRS: dimensionality of the Motor Section revisited

The dimensionality and reliability of the Motor Section of the Unified Parkinson Disease Rating Scale (UPDRS III) was studied with non-parametric Mokken scale analysis. UPDRS measures were obtained on 147 patients with PD (96 men, 51 women, mean age 61, range 35-80 yrs). Mokken scale analysis revealed a four-dimensional structure of the UPDRS III. Left-sided bradykinesia and rigidity appeared to co-occur with axial signs, gait disturbance, and speech/hypomimia, whereas right-sided bradykinesia and rigidity formed a second scale. Two further small scales were found consisting of right- and left-sided tremor. Results from the scale analysis reveal that all four subscales are strong. The reliability of the two tremor scales is low because they only contain three and four items, respectively.

Myoclonus or tremor in orthostatism: an under-recognized cause of unsteadiness in Parkinson's disease

Patients with Parkinson's disease (PD) often complain of unsteadiness. This can occur as the result of various neurological dysfunctions, including changes in postural adjustments, loss of postural reflexes, axial akinesia and rigidity, freezing and/or postural hypotension. In some cases these symptoms remain unexplained, and rare cases of unsteadiness have been attributed to tremor on standing. To delineate this condition, we investigated 11 consecutive PD patients with unexplained unsteadiness because of tremor on standing, seen in our department over a 6-year period. All the patients had detailed clinical and electrophysiological investigations based on surface polygraphic electromyographic recordings. Four patients had fast orthostatic tremor (13-18 Hz), one had intermediate orthostatic tremor (8-9 Hz), and three had slow orthostatic tremor (4-6 Hz). The remaining 3 patients had orthostatic myoclonus, a condition that has not previously been reported in PD. Patients with fast tremor improved on clonazepam. Patients with slow tremor and myoclonus improved on levodopa and sometimes benefited further when clonazepam was added. These observations show the usefulness of neurophysiological investigations for diagnosing and treating unexplained unsteadiness in Parkinson's disease.

[123I]FP-CIT striatal binding in early Parkinson's disease patients with tremor vs. akinetic-rigid onset

We performed [123I]FP-CIT/SPECT in 20 drug-naive Parkinson's disease (PD) patients, 10 with unilateral akinesia/rigidity at onset (arPD) and 10 with additional tremor-at-rest (tPD), to evaluate whether resting tremor at onset is associated with differences in striatal dopamine transporter binding. Patients of the two cohorts were matched for age, disease duration (<3 years) and severity of non-tremor motor symptoms; 31 healthy participants served as controls. Mean striatal dopamine transporter binding reduction in PD patients vs. controls was 42% for arPD and 50% for tPD; mean ipsilateral striatum and caudate nucleus uptake values were lower by 12 and 24%, respectively, in tPD than arPD. We conclude that widespread degeneration of the nigrostriatal dopaminergic pathway might be necessary for the development of parkinsonian tremor-at-rest.

Extrapyramidal signs, primitive reflexes and incontinence in fronto-temporal dementia

According to the diagnostic consensus criteria [1] akinesia, rigidity and tremor as well as primitive reflexes and incontinence support the diagnosis of fronto-temporal dementia (FTD). However, the prevalence of extrapyramidal signs (EPMS), primitive reflexes and incontinence in FTD has not yet been systematically studied. In the present study, thirty-one patients with mild or moderate FTD without previous or present antipsychotic medication underwent a detailed neurological exam including the motor part of the Unified Parkinson's Disease Rating Scale (UPDRS). The average total score on the motor subscale of the UPDRS was 14.0 points. Akinesia and Parkinsonian gait or posture were found frequently but were mild in most instances. Rigidity was found in 36% of the patients. Resting tremor was a rare symptom. The only primitive reflex that occurred was a positive palmomental that was found in 7% of the patients. Urinary incontinence was present in 26%. The results have to be confirmed with larger or pooled patient samples from different ascertainment scenarios. If the results of the present study can be replicated, a revision of the consensus criteria from 1998 might be considered.

Axial hypertonicity in Parkinson's disease: direct measurements of trunk and hip torque

A cardinal feature of Parkinson's disease (PD) is muscle hypertonicity, i.e. rigidity. Little is known about the axial tone in PD or the relation of hypertonia to functional impairment. We quantified axial rigidity to assess its relation to motor symptoms as measured by UPDRS and determine whether rigidity is affected by levodopa treatment. Axial rigidity was measured in 12 PD and 14 age-matched controls by directly measuring torsional resistance of the longitudinal axis to twisting (+/-10 degrees ). Feet were rotated relative to fixed hips (Hip Tone) or feet and hips were rotated relative to fixed shoulders (Trunk Tone). To assess tonic activity only, low constant velocity rotation (1 degrees /s) and low acceleration (<12 degrees /s(2)) were used to avoid eliciting phasic sensorimotor responses. Subjects stood during testing without changing body orientation relative to gravity. Body parts fixed against rotation could translate laterally within the boundaries of normal postural sway, but could not rotate. PD OFF-medication had higher axial rigidity (p<0.05) in hips (5.07 N m) and trunk (5.30 N m) than controls (3.51 N m and 4.46 N m, respectively), which did not change with levodopa (p>0.10). Hip-to-trunk torque ratio was greater in PD than controls (p<0.05) and unchanged by levodopa (p=0.28). UPDRS scores were significantly correlated with hip rigidity for PD OFF-medication (r values=0.73, p<0.05). Torsional resistance to clockwise versus counter-clockwise axial rotation was more asymmetrical in PD than controls (p<0.05), however, there was no correspondence between direction of axial asymmetry and side of disease onset. In conclusion, these findings concerning hypertonicity may underlie functional impairments of posture and locomotion in PD. The absence of a levodopa effect on axial tone suggests that axial and appendicular tones are controlled by separate neural circuits.

Evaluation of Dopaminergic Function in Frontotemporal Dementia Using 123I-FP-CIT Single Photon Emission Computed Tomography

Extrapyramidal symptoms are observed in frontotemporal dementia (FTD). (123)I-FP-CIT (DaT scan) single photon emission computed tomography (SPECT) can detect loss of presynaptic dopamine transporters in the striatum. We aimed to evaluate the dopaminergic status of the striatum in patients with FTD using DaT scan. Seven patients (age range 65-76 years), who fulfilled the Neary criteria and in whom the diagnosis of FTD was confirmed by hexamethylpropyleneamine oxime SPECT, were included in the study. The severity of the extrapyramidal symptoms was evaluated by the motor part of the Unified Parkinson's Disease Rating Scale (UPDRS). SPECT using (123)I-FP-CIT was done. A (region - occipital)/occipital ratio was calculated for the striatum, putamen and caudate nucleus. The results were compared with those of the 7 age-matched normal controls. The uptake of the radiotracer in the right and left striatum was reduced to 62% (p = 0.000) and 68% (p = 0.000), respectively, compared to controls. The motor UPDRS score of the patients with FTD showed a negative correlation to the uptake of the radiotracer. The presynaptic dopamine transporter in FTD is impaired, related to the severity of the extrapyramidal symptoms. Since an effective treatment for FTD is still to be established, there is a need for evaluating the efficacy of dopaminergic drugs.

Predictors of diagnosis in Huntington disease

OBJECTIVE

Subtle signs and symptoms of Huntington disease (HD) are often present before impairments reach a point where the neurologic disease is manifest and a diagnosis must be considered. The objective is to examine the prognostic significance of these early clinical signs and symptoms regarding time until unequivocal clinical HD diagnosis.

METHODS

We analyzed longitudinal data from 218 at-risk but healthy participants in the Huntington Study Group database who had either normal motor examination results or minimal soft motor signs at first observation. This group was followed periodically in HD clinics for up to 4.5 years. We used survival analysis to examine predictors of time until HD diagnosis.

RESULTS

Diagnostic prediction was significantly improved using specific, nonredundant items from the Unified Huntington's Disease Rating Scale. When a movement disorder specialist initially had a global impression of "soft signs" present, cumulative relative risk of diagnosis was 4.68 times greater at 1.5 years of follow-up and 3.58 at 3 years. A neuropsychological test pattern with psychomotor speed 1 SD worse than a semantic knowledge measure increased cumulative risk by 1.99 times at 1.5 years and 1.81 at 3 years. Finally, reports of various subjective HD symptoms increased 3-year relative risk by 2.6 to 3.4.

CONCLUSIONS

Findings demonstrate that neuropsychological performance and both the clinician rating and the patient subjective perception of motor difficulties contribute nonredundantly to a prediction of Huntington disease diagnosis. These findings may have implications for prognostic assessment of persons at risk and eventually assist with early interventions.

Fatal Neurotoxic Response to Neuroleptic Medications

Neuroleptic malignant syndrome (NMS) is a diagnosis of exclusion difficult to make due to a lack of pathognomonic features. Diagnosing NMS by postmortem examination becomes increasingly challenging when possible underlying brain pathology is obscured. The diagnosis is based on clinical history and laboratory findings. Autopsy and histologic findings, if any, usually are reflective of hyperthermia or complications (eg, aspiration pneumonia) of NMS. The authors describe a case of a 36-year-old Hispanic woman with a presumptive diagnosis of pseudoseizures, treated with various combinations of neuroleptic medications over a 6-week period prior to her sudden, unexpected, in-hospital death. Neuroleptic malignant syndrome is likely to have contributed to this patient's death. Confounding factors and medicolegal issues of a postmortem diagnosis of NMS are discussed.

[Effect of modified unilaterally-open expansive laminoplasty using bridge grafting and restructing posterior ligamentous complex methods on axial symptoms and cervical curvature change]

OBJECTIVE

To explore if the modified unilaterally-open expansive laminoplasty using bridge grafting and reconstructing posterior ligamentous complex methods is effective in preventing persisting axial symptoms, restriction of neck motion, and loss of cervical curvature.

METHODS

From June 2000 to October 2005, 138 patients with cervical spondylotic myelopathy underwent this procedure. Of them, 78 who were followed for more than 2 years (group A) were included in this study. Another 69 patients who underwent conventional unilaterally open-door laminoplasty served as controls (group B). The JOA scores and the incidence of newly developed or deteriorated axial symptoms were recorded. Preoperative and postoperative ranges of neck motion were measured on lateral flexion and extension radiographs. Preoperative and postoperative cervical curvature indices were calculated according to Ishihara's method.

RESULTS

The patients of group A were followed 24-44 months (mean 33 months), and the patients of group B were followed 24-53 months(mean 35 months). The operative time was 114+/-20 min in group A and 70+/-25 min in group B, showing statistically significant difference (P<0.05). The operative blood loss was 280+/-72 ml in group A and 210+/-80 ml in group B (P>0.05). According to JOA scoring, the average recovery rates were 67.0%+/-17.3% in group A and 65.0%+/-21.4% in group B (P>0.05). Postoperative development or deterioration of axial symptoms occurred in 12% of patients in group A and 51% of patients in group B, showing statistically significant difference (P<0. 05). Postoperative range of neck motion was 88.0%+/-10.1% of the preoperative one in group A and 64.0%+/-16.3% in group B (P< 0.05). There was no significant difference between preoperative (15.3+/-8.2) and postoperative (13.5+/-9.3) cervical curvature index in group A, whereas the mean value of postoperative index (11.1+/-5.7) was significantly smaller than that of preoperative one (17.2+/-13.5) in group B (P<0.05).

CONCLUSION

This new procedure was less invasive to the posterior extensor mechanism than the conventional unilaterally-open laminoplasty and was effective in preventing postoperative morbidities.

Contribution of Jules Froment to the study of Parkinsonian rigidity

Rigidity is commonly defined as a resistance to passive movement. In Parkinson's disease (PD), two types of rigidity are classically recognized which may coexist, "leadpipe " and "cogwheel". Charcot was the first to investigate parkinsonian rigidity during the second half of the nineteenth century, whereas Negro and Moyer described cogwheel rigidity at the beginning of the twentieth century. Jules Froment, a French neurologist from Lyon, contributed to the study of parkinsonian rigidity during the 1920s. He investigated rigidity of the wrist at rest in a sitting position as well as in stable and unstable standing postures, both clinically and with physiological recordings using a myograph. With Gardère, Froment described enhanced resistance to passive movements of a limb about a joint that can be detected specifically when there is a voluntary action of another contralateral body part. This has been designated in the literature as the "Froment's maneuver " and the activation or facilitation test. In addition, Froment showed that parkinsonian rigidity diminishes, vanishes, or enhances depending on the static posture of the body. He proposed that in PD "maintenance stabilization " of the body is impaired and that "reactive stabilization " becomes the operative mode of muscular tone control. He considered "rigidification " as compensatory against the forces of gravity. Froment also demonstrated that parkinsonian rigidity increases during the Romberg test, gaze deviation, and oriented attention. In their number, breadth, and originality, Froment's contributions to the study of parkinsonian rigidity remain currently relevant to clinical and neurophysiological issues of PD.

Orthostatic mesodiencephalic dysfunction after decompressive craniectomy

An extreme syndrome of the trephined after decompressive craniectomy is reported here. The most extensive clinical syndrome observed was established over 4 weeks and consisted of bradypsychia, dysartria, and limb rigidity with equine varus feet predominating on the right. The syndrome was aggravated when the patient was sitting with the sequential appearance over minutes of a typical parkinsonian levodopa-resistant tremor starting on the right side, extending to all four limbs, followed by diplopia resulting from a left abducens nerve palsy followed by a left-sided mydriasis. All signs recovered within 1-2 h after horizontalisation. It was correlated with an orthostatic progressive sinking of the skin flap, MRI and CT scan mesodiencephalic distortion without evidence of parenchymal lesion. Brain stem auditory evoked potential wave III latency increases were observed on the right side on verticalisation of the patient. EEG exploration excluded any epileptic activity. Symptoms were fully recovered within 2 days after cranioplasty was performed. The cranioplasty had to be removed twice due to infection. Bradypsychia, speech fluency, limb rigidity and tremor reappeared within a week after removal of the prosthesis. While waiting for sterilisation of the operative site, the symptoms were successfully prevented by a custom-made transparent suction-cup helmet before completion of cranioplasty.