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Background: Malignant hyperthermia (MH) is an inherited muscle disorder induced by volatile anesthetics and depolarizing muscle relaxants. While the incidence of MH is high in young, there are few reports on the clinical features of pediatric MH. In this study, we selected pediatric cases from an MH database and analyzed the clinical findings by age group. We hypothesized that there would be age-related differences in the clinical characteristics., Methods: A retrospective analysis of MH data collected in our database during 1960 to 2020 was performed to identify pediatric subjects (≤18 years) with a Clinical Grading Scale of ≥35, indicating "very likely" or "almost certain" MH. We compared clinical characteristics among the 0 to 24 month, 2 to 12 year, and 13 to 18 year (youngest, middle, and oldest, respectively) age groups., Results: Data were available for 187 patients: 15 in the youngest age group, 123 in the middle-aged group, and 49 in the oldest age group. Of these, 55 patients (29.4%) had undergone muscle biopsy and muscle contracture test. The mortality rates during the study period were 13.3%, 13.8%, 20.4%, and 15.5% in the youngest, middle, and oldest cohorts and overall, respectively. In contrast, the overall mortality rate from 2000 to 2020 was 8.8%. The most frequent initial symptoms of MH were elevated temperature (46.7%) and generalized muscular rigidity (26.7%) in the youngest cohort, masseter spasm (35.0%) and generalized muscular rigidity (19.5%) in the middle cohort, and elevated end-tidal carbon dioxide (26.5%) and tachycardia (22.4%) in the oldest cohort. Physical examination revealed that elevated temperature, sinus tachycardia, and respiratory acidosis occurred frequently in all groups. The middle cohort had high frequencies of masseter spasm (58.4%; P = .02) and dark urine (75.5%; P = .01) compared to those in the oldest groups, and had a higher peak creatine kinase level compared to those in the 3 groups. Skeletal muscle symptoms tended to be more common in patients administered succinylcholine (generalized muscular rigidity, P = .053; masseter spasm, P < .0001; dark urine, P < .0001). In particular, masseter spasm and dark urine were more common in the middle cohort when succinylcholine was administered (masseter spasm: versus youngest cohort, P = .06, versus oldest cohort, P = .027; dark urine: versus youngest cohort, P = .0072, versus oldest cohort, P = .0015)., Conclusions: The clinical characteristics of pediatric patients with MH vary according to age group. The difference in initial symptoms of MH depending on age group is noteworthy information for the early diagnosis of MH., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2021 International Anesthesia Research Society.)

Patients with DYT1 dystonia caused by the mutated TOR1A gene exhibit risk neutral behaviour compared to controls who are risk averse in the same reinforcement learning task. It is unclear whether this behaviour can be linked to changes in cortico-striatal plasticity demonstrated in animal models which share the same TOR1A mutation. We hypothesised that we could reproduce the experimental risk taking behaviour using a model of the basal ganglia under conditions where cortico-striatal plasticity was abnormal. As dopamine exerts opposing effects on cortico-striatal plasticity via different receptors expressed on medium spiny neurons (MSN) of the direct (D1R dominant, dMSNs) and indirect (D2R dominant, iMSNs) pathways, we tested whether abnormalities in cortico-striatal plasticity in one or both of these pathways could explain the patient's behaviour. Our model could generate simulated behaviour indistinguishable from patients when cortico-striatal plasticity was abnormal in both dMSNs and iMSNs in opposite directions. The risk neutral behaviour of the patients was replicated when increased cortico-striatal long term potentiation in dMSN's was in combination with increased long term depression in iMSN's. This result is consistent with previous observations in rodent models of increased cortico-striatal plasticity at in dMSNs, but contrasts with the pattern reported in vitro of dopamine D2 receptor dependant increases in cortico-striatal LTP and loss of LTD at iMSNs. These results suggest that additional factors in patients who manifest motor symptoms may lead to divergent effects on D2 receptor dependant cortico-striatal plasticity that are not apparent in rodent models of this disease., Competing Interests: The authors have declared that no competing interests exist

Parkinson's disease is one of the most described neurodegenerative pathologies; though it is one of the most complex pathologies, is not fully understood, correctly identified, with its different types of presentation, its clinical course and the neural networks involved. We report on a series consisting of 432 de novo PD diagnosed patients, and 457 control cases. We identify a possible independent relationship between two clinical PD presentation, akinetic-rigid and tremor-dominant, and cognitive and behavioral changes. A 24-months follow-up allows to identify new information still not fully explored., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Clinical assessments for many musculoskeletal disorders involve evaluation of muscle stiffness, although it is not yet possible to obtain quantitative estimates from individual muscles. Ultrasound elastography can be used to estimate the material properties of unstressed, homogeneous, and isotropic materials by tracking the speed of shear wave propagation; these waves propagate faster in stiffer materials. Although elastography has been applied to skeletal muscle, there is little evidence that shear wave velocity (SWV) can directly estimate muscle stiffness since this tissue violates many of the assumptions required for there to be a direct relationship between SWV and stiffness. The objective of this study was to evaluate the relationship between SWV and direct measurements of muscle force and stiffness in contracting muscle. Data were collected from six isoflurane-anesthetized cats. We measured the short-range stiffness in the soleus via direct mechanical testing in situ and SWV via ultrasound imaging. Measurements were taken during supramaximal activation at optimum muscle length, with muscle temperature varying between 26°C and 38°C. An increase in temperature causes a decrease in muscle stiffness at a given force, thus decoupling the tension-stiffness relationship normally present in muscle. We found that increasing muscle temperature decreased active stiffness from 4.0 ± 0.3 MPa to 3.3 ± 0.3 MPa and SWV from 16.9 ± 1.5 m/s to 15.9 ± 1.6 m/s while force remained unchanged (mean ± SD). These results demonstrate that SWV is sensitive to changes in muscle stiffness during active contractions. Future work is needed to determine how this relationship is influenced by changes in muscle structure and tension. NEW & NOTEWORTHY Shear wave ultrasound elastography is a noninvasive tool for characterizing the material properties of muscle. This study is the first to compare direct measurements of stiffness with ultrasound measurements of shear wave velocity (SWV) in a contracting muscle. We found that SWV is sensitive to changes in muscle stiffness, even when controlling for muscle tension, another factor that influences SWV. These results are an important step toward developing noninvasive tools for characterizing muscle structure and function.

Rationale: In this case report, we describe a Parkinson's disease (PD) patient with limb-kinetic apraxia (LKA) in whom degeneration of the corticofugal tract (CFT) from the supplementary motor area (SMA) was observed in diffusion tensor tractography (DTT)., Patient Concerns: A 63-year-old woman presented with a loss of dexterity in both upper extremities, which indicated LKA, and typical PD-related symptoms, including a gait disturbance with a short step, resting tremor in both upper extremities, and rigidity, and these symptoms had been present for 2 years. The F-florinated-N-3-fluoropropyl-2-β-carboxymethoxy-3-β-(4-lodophenyl) nortropane positron emission tomography scanning findings were consistent with PD. Based on the clinical symptoms and imaging findings, we diagnosed the patient with PD. In a coin-rotation test that was used to evaluate the severity of the LKA, the patient's results significantly decreased compared to the results of the normal controls., Diagnoses: The DTT showed that the CFTs from the SMAs in both hemispheres were partially torn and thinned. The fractional anisotropy values and CFT volumes in both SMAs were >2 standard deviations lower than those of the normal controls., Interventions: The patient was treated with an initial dose of 150/37.5 mg/day of levodopa/benserazide, and the dose was gradually increased to 400/100 mg/day., Outcomes: After treatment, although the bradykinesia, rigidity, and resting tremor of the patient significantly decreased, the dexterity of the patient's hands did not improve., Lessons: These observations indicated degeneration of the CFTs from the SMAs in both hemispheres in the patient. This degeneration might have, at least in part, contributed to the patient's LKA. The results of this study suggest that CFT degeneration could be one of the pathological mechanisms underlying LKA in patients with PD., (Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.)

Classical motor symptoms of Parkinson's disease (PD) such as tremor, rigidity, bradykinesia, and axial symptoms are graded in the Movement Disorders Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) III. It is yet to be ascertained whether parkinsonian motor symptoms are associated with different anatomical patterns of neurodegeneration as reflected by brain grey matter (GM) alteration. This study aimed to investigate associations between motor subscores and brain GM at voxel level. High resolution structural MRI T1 scans from the Parkinson's Progression Markers Initiative (PPMI) repository were employed to estimate brain GM intensity of PD subjects. Correlations between GM intensity and total MDS-UPDRS III and its four subscores were computed. The total MDS-UPDRS III score was significantly negatively correlated bilaterally with putamen and caudate GM density. Lower anterior striatal GM intensity was significantly associated with higher rigidity subscores, whereas left-sided anterior striatal and precentral cortical GM reduction were correlated with severity of axial symptoms. No significant morphometric associations were demonstrated for tremor subscores. In conclusion, we provide evidence for neuroanatomical patterns underpinning motor symptoms in early PD.

Background: It is not known how passive muscle length and stiffness contribute to rigidity in Parkinson's disease. The objective of this study was to compare passive gastrocnemius muscle-tendon slack length and stiffness at known tension in Parkinson's disease subjects with ankle rigidity and in able-bodied people., Methods: Passive ankle torque-angle curves were obtained from 15 Parkinson's disease subjects with rigidity and 15 control subjects. Torque-angle data were used to derive passive gastrocnemius length-tension data and calculate slack length and stiffness of the gastrocnemius muscle. Between-group comparisons were made with linear models., Results: Gastrocnemius muscle-tendon slack lengths (adjusted between-group difference, 0.01 m; 95% CI, -0.02 to 0.04 m; P = 0.37) and stiffness (adjusted between-group difference, 15.7 m -1 ; 95% CI, -8.5 to 39.9 m -1 ; P = 0.19) were not significantly different between groups., Conclusions: Parkinson's disease subjects with ankle rigidity did not have significantly shorter or stiffer gastrocnemius muscles compared with control subjects. © 2016 International Parkinson and Movement Disorder Society., (© 2016 International Parkinson and Movement Disorder Society.)

Background: Acupuncture is increasingly used to treat patients with erectile dysfunction (ED), and our systematic review aimed to evaluate the current evidence for the efficacy and safety of acupuncture in treating ED., Methods: An electronic search was conducted in eight databases to identify randomized controlled trials (RCTs) of acupuncture for treating erectile dysfunction that were published in English and Chinese. The Cochrane Risk of Bias tool was used to assess the risk of bias., Results: Three RCTs with a total of 183 participants met the inclusion criteria. One trial showed the beneficial effects of acupuncture compared with sham acupuncture while the others did not. One trial suggested that acupuncture combined with psychological therapy was superior to psychological therapy alone. However, the overall methodological and reporting quality of the studies was low. The safety of acupuncture for ED was unclear because there were too few reports on this topic., Conclusion: The available evidence supporting that acupuncture alone improves ED was insufficient and the available studies failed to show the specific therapeutic effect of acupuncture. Future well-designed and rigorous RCTs with a large sample size are required. This trial is registered with CRD42014013575.

Objective: The NeuroFlexor is a novel method incorporating a biomechanical model for the measurement of neural and nonneural contributions to resistance induced by passive stretch. In this study, we used the NeuroFlexor method to explore components of passive movement resistance in the wrist and finger muscles in subjects with Parkinson's disease (PD)., Methods: A cross-sectional comparison was performed in twenty-five subjects with PD with clinically identified rigidity and 14 controls. Neural (NC), elastic (EC), and viscous (VC) components of the resistance to passive extension of the wrist were calculated using the NeuroFlexor. Measurements were repeated during a contralateral activation maneuver., Results: PD subjects showed greater total resistance (P < 0.001) and NC (P = 0.002) compared to controls. EC and VC did not differ significantly between groups. Contralateral activation maneuver resulted in increased NC in the PD group but this increase was due to increased resting tension. Total resistance and NC correlated with clinical ratings of rigidity and with bradykinesia., Conclusions: The findings suggest that stretch induced reflex activity, but not nonneural resistance, is the major contributor to rigidity in wrist muscles in PD. The NeuroFlexor is a potentially valuable clinical and research tool for quantification of rigidity.

Background: Following Helicobacter pylori eradication in a placebo-controlled trial, the hypokinesia of idiopathic parkinsonism improved but flexor rigidity worsened., Methods: We surveyed the effect of all antimicrobial prescriptions in 66 patients with idiopathic parkinsonism over a median of 1.9 (interquartile range 0.4, 3.5) years. Initial Helicobacter screening was followed (where positive) by gastric biopsy. Serial lactulose hydrogen breath tests (364 tests) for small intestinal bacterial overgrowth monitored the need to encourage fluid intake and bulk/osmotic laxatives. We measured hypokinesia (401 assessments of mean stride length at free walking speed in 58 patients) and upper limb flexor rigidity (396 assessments in 49)., Results: Following successful H. pylori eradication (12 cases) but not failed (2), stride increased in entire group (including those receiving levodopa), core group (those receiving only longer-t½ antiparkinsonian medication or untreated) and untreated (p = .001 each case). The effect was greater with less antiparkinsonian medication (19 (95% CI, 14, 25) cm/year in untreated). Flexor rigidity was unchanged. Following antimicrobials for other indications (75 courses), hypokinesia was unchanged. However, flexor rigidity increased cumulatively. It increased in core group only after a first course (by (10 (0, 20)%/year, p = .05)), but then in entire, core and untreated after a second course (18 (6, 31), 33 (19, 48) and 29 (12, 48)%/year respectively; p = .002, .001 and .001) and further still after a third (17 (2, 34), 23 (8, 41) and 38 (15, 65)%/year; p = .02, .003 and .001). Initially, 40/66 were lactulose hydrogen breath test positive. Odds for positivity fell with time (by 59 (46, 75)%/year, p = .001) and tended to be lower with Helicobacter positivity (28 (8, 104)%, p = .06), but were unrelated to other antimicrobial interventions., Conclusions: Improved hypokinesia following antimicrobials appeared unique to Helicobacter eradication. Rigidity increased following successive antimicrobial exposures for other indications, despite diminishing lactulose hydrogen breath test positivity., (© 2013 John Wiley & Sons Ltd.)

Objective: To evaluate in detail the clinical features in a large series of pathologically confirmed cases of vascular Parkinsonism (VP)., Background: In the absence of widely accepted diagnostic criteria for VP pathological confirmation of diagnosis is necessary to ensure diagnostic reliability, and has only been reported in a few small series., Design/methods: The archival records of the Queen Square Brain Bank (QSBB) have been used to identify cases of Parkinsonism where cerebrovascular disease was the only pathological finding. Clinical notes were scrutinised and milestones of disease progression were compared with other atypical Parkinsonian syndromes from previous QSBB studies., Results: Twenty-eight cases were included. Mean age of onset and disease duration were 70.6 (SD± 6.42) and 10.5 (SD± 66.1) years respectively. Bradykinesia was present in all cases, rigidity in 96%, falls in 76%, pyramidal signs in 54%, urinary incontinence in 50% and dementia in 39%.Visual hallucinations in 0%. Two-thirds had an insidious onset and a relentless rather than stepwise progression of disability. When compared with other Parkinsonian syndromes, VP had an older age of onset., Conclusions: In comparison with other Parkinsonian syndromes the patients were older and had an extremely low frequency of visual hallucinations compared with Parkinson's disease.

The pathology of Parkinson's disease (PD) is not confined to the nigrostriatal dopaminergic pathway, but also involves widespread cerebral cortical areas. Such non-nigrostriatal lesions may contribute to disabling dopa-resistant parkinsonian motor deficits. We performed cortical thickness analysis to identify cerebral cortical brain areas in which thickness correlates with the severity of parkinsonian motor deficits. We performed T1-weighted brain magnetic resonance imaging studies in 142 PD patients. Motor scores on the Unified Parkinson's Disease Rating Scale (UPDRS) were measured, and subscores were calculated for bradykinesia, rigidity, tremor, and axial motor deficits. Using FreeSurfer software, we studied cortical areas in which thickness correlates with disease duration or the severity of parkinsonian motor deficits. The cortical thickness of the parieto-temporal association cortex, including the inferior parietal and posterior parietal cortices, showed a negative correlation with disease duration, total UPDRS motor score, and UPDRS subscores for bradykinesia and axial motor deficits. We found no cortical areas in which thickness correlated with subscores for tremor and rigidity. In addition to nigrostriatal dopaminergic deficit, progressive thinning of the parieto-temporal sensory association cortices related to disease duration seems to be related in part to the exacerbation of bradykinesia and the axial motor symptoms of PD.

Background: The syndrome of progressive encephalopathy with limb rigidity has been historically termed progressive encephalomyelitis with rigidity and myoclonus (PERM) or stiff-person syndrome plus., Methods: The case is presented of a previously healthy 28-year-old man with a rapidly fatal form of PERM developing over 2 months., Results: Serum antibodies to both NMDA receptors (NMDAR) and glycine receptors (GlyR) were detected postmortem, and examination of the brain confirmed an autoimmune encephalomyelitis, with particular involvement of hippocampal pyramidal and cerebellar Purkinje cells and relative sparing of the neocortex. No evidence for an underlying systemic neoplasm was found., Conclusion: This case displayed not only the clinical features of PERM, previously associated with GlyR antibodies, but also some of the features associated with NMDAR antibodies. This unusual combination of antibodies may be responsible for the particularly progressive course and sudden death.

Extrapontine myelinolysis in association with the more common central pontine variety is increasingly reported. Although typically associated with rapid correction of hyponatraemia, myelinolysis is also seen when sodium correction occurs at recommended rates. We present a 60-year-old man who developed hyponatraemia and hypokalaemia due to repeated vomiting. An acute symmetric akinetic-rigid syndrome followed correction of hyponatraemia, performed in line with current guidelines. There were no clinical features of pontine involvement even though a typical lesion was seen on MRI. Bilateral putaminal and caudate lesions were seen. He recovered well with only symptomatic treatment. Myelinolysis can present with features of extrapontine involvement with the pontine lesions remaining asymptomatic. Current guidelines for the correction of hyponatraemia do not prevent development of myelinolysis in all instances. In contrast to the generally expected poor outcome in this condition, patients do make a good recovery with symptomatic treatment and good nursing care., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

In this work we demonstrate for the first time the use of Förster resonance energy transfer (FRET) as an assay to monitor the dynamics of cross-bridge conformational changes directly in single muscle fibres. The advantage of FRET imaging is its ability to measure distances in the nanometre range, relevant for structural changes in actomyosin cross-bridges. To reach this goal we have used several FRET couples to investigate different locations in the actomyosin complex. We exchanged the native essential light chain of myosin with a recombinant essential light chain labelled with various thiol-reactive chromophores. The second fluorophore of the FRET couple was introduced by three approaches: labelling actin, labelling SH1 cysteine and binding an adenosine triphosphate (ATP) analogue. We characterise FRET in rigor cross-bridges: in this condition muscle fibres are well described by a single FRET population model which allows us to evaluate the true FRET efficiency for a single couple and the consequent donor-acceptor distance. The results obtained are in good agreement with the distances expected from crystallographic data. The FRET characterisation presented herein is essential before moving onto dynamic measurements, as the FRET efficiency differences to be detected in an active muscle fibre are on the order of 10-15% of the FRET efficiencies evaluated here. This means that, to obtain reliable results to monitor the dynamics of cross-bridge conformational changes, we had to fully characterise the system in a steady-state condition, demonstrating firstly the possibility to detect FRET and secondly the viability of the present approach to distinguish small FRET variations.

The aim of this study is to evaluate shoulder disturbances in Parkinson's disease (PD) patients using magnetic resonance imaging (MRI) which is the best tool in the demonstration of complex shoulder pathologies; and to determine probable relations between shoulder pathologies and PD clinical features. Twenty-eight PD patients with a total of 56 shoulders were used as the study group while 13 age-matched cases with 26 shoulders were used as the control group (CG) in the study. Both patients with PD and the CG underwent shoulder MRI. The Hoehn and Yahr (H&Y) disability scale and Unified Parkinson's Disease Rated Scale (UPDRS) were used to determine the severity of the disease. Our results showed that patients with full-thickness supraspinatus (SSP) tear have statistically significant higher UPDRS (P = 0.012), tremor (P = 0.023), rigidity (P = 0.023), and total (P = 0.002) scores. Mild group patients (P = 0.045) showed significantly higher frequency resting tremor and subcoracoid effusion than those of severe group patients (P = 0.002). Subcoracoid effusion was observed in patients with significantly higher UPDRS (P = 0.045) and rigidity (P = 0.022) scores. When the resting tremor and subcoracoid effusion groups were compared according to the severity of the resting tremor but not according to the H&Y, higher frequency of full-thickness tear in SSP tendon was detected in the group of resting tremor (P = 0.053). Longer duration of disease was also observed in patients with full-thickness SSP tear (P = 0.029) and acromioclavicular joint changes (P = 0.018). Higher UPDRS, tremor, rigidity and total scores and longer PD duration appear as the predisposing factors for the development of shoulder disturbances in PD in this study., (© 2010 Movement Disorder Society.)

Background: Mitochondrial diseases are characterized by wide phenotypic and genetic variability, but presentations in adults with akinetic rigidity and hyperkinetic movement disorders are rare., Objectives: To describe clinically a subject with progressive neurodegeneration characterized by psychosis, dementia, and akinesia-rigidity, and to associate this phenotype with a novel mitochondrial transfer RNA(Phe) (tRNA(Phe)) (MTTF) mutation., Design, Setting, and Patient: Case description and detailed laboratory investigations of a 57-year-old woman at a university teaching hospital and a specialist mitochondrial diagnostic laboratory., Results: Histopathological findings indicated that an underlying mitochondrial abnormality was responsible for the subject's progressive neurological disorder, with mitochondrial genome sequencing revealing a novel m.586G>A MTTF mutation., Conclusions: The clinical phenotypes associated with mitochondrial disorders may include akinesia-rigidity and psychosis. Our findings further broaden the spectrum of neurological disease associated with mitochondrial tRNA(Phe) mutations.

We report a case of acquired microcephaly in a male infant. Testing for mutations in the MECP2 gene identified a de novo hemizygous c.378-3C>G mutation at a highly conserved 3' splice site, consistent with Rett syndrome. Other distinctive features included periodic hypertonicity, decreased mitochondrial complex III activity, and abnormal magnetic resonance imaging (MRI) T2 signal in the pons. Rett syndrome was originally described in females with a clinical phenotype of deceleration of head growth, abnormal hand movements, and developmental regression. The clinical diagnosis can now be supported by genetic testing for MECP2 mutations, and the phenotype of disorder has expanded. Cases of Rett syndrome in males are rare and a total of 17 such cases have been reported. This case extends the clinical phenotype of Rett syndrome in males and associates this mutation with mitochondrial dysfunction.

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.

Myotilinopathies are a group of muscle disorders caused by mutations in the MYOT gene. It was first described in two families suffering from limb girdle muscle dystrophy type 1 (LGMD 1A), and later identified in a subset of dominant or sporadic patients suffering from myofibrillar myopathy, as well as in a family with spheroid body myopathy. Disease phenotypes associated with MYOT mutations are clinically heterogeneous and include pure LGMD forms as well as late-onset distal myopathies. We report here on a 53-year-old male suffering from a unique clinical profile characterized by generalized symmetrical increase in muscle bulk leading to a Herculean appearance. Muscle weakness and stiffness in the lower extremities were the patient's main complaints. Muscle MRI showed extensive fatty infiltration in the thigh and leg muscles and a muscle biopsy showed a myofibrillar myopathy with prominent protein aggregates. Gene sequencing revealed a Ser55Phe missense mutation in the myotilin gene. The mutation was identified in his older brother, who presented a mild hypertrophic appearance and had a myopathic pattern in EMG, despite not presenting any of the complaints of the proband and having normal muscle strength. This finding, and his deceased father and paternal aunt's similar gait disorders, suggest that this is in fact a new autosomal dominant kindred. The present observations further expand the spectrum of clinical manifestations associated with mutations in the myotilin gene.

We present the case of an 81-year-old female with severe rigidity, stiffness and superimposed muscle spasms that represents the oldest reported patient with progressive encephalomyelitis with rigidity and myoclonus. Two associated autoimmune disorders (diabetes mellitus and Hashimoto's thyoiditis) were recently diagnosed. A paraneoplastic origin was excluded. The spectrum of differential diagnoses including classic Stiff-Person syndrome and paraneoplastic Stiff-Person syndrome is discussed.

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.

Motor parkinsonism is characterised by bradykinesia, muscle rigidity, postural instability and resting tremor that occur most often in Parkinson's disease, multiple system atrophy and progressive supranuclear palsy. In all three disorders the main regulators of the caudate nucleus and putamen (dopaminergic substantia nigra and glutaminergic caudal intralaminar nuclei), as well as the cortical projection from the presupplementary motor area, degenerate. Degeneration of the major basal ganglia circuit neurons also occurs in multiple system atrophy, while degeneration of the subthalamus and a widespread loss of inhibitory interneurons within the extrapyramidal system occurs in progressive supranuclear palsy.

Subfragment 2 (S2), the segment that links the two myosin heads to the thick filament backbone, may serve as a swing-out adapter allowing crossbridge access to actin, as the elastic component of crossbridges and as part of a phosphorylation-regulated on-off switch for crossbridges in smooth muscle. Low-salt expansion increases interfilament spacing (from 52 nm to 67 nm) of rigor insect flight muscle fibers and exposes a tethering segment of S2 in many crossbridges. Docking an actoS1 atomic model into EM tomograms of swollen rigor fibers identifies in situ for the first time the location, length and angle assignable to a segment of S2. Correspondence analysis of 1831 38.7 nm crossbridge repeats grouped self-similar forms from which class averages could be computed. The full range of the variability in angles and lengths of exposed S2 was displayed by using class averages for atomic fittings of acto-S1, while S2 was modeled by fitting a length of coiled-coil to unaveraged individual repeats. This hybrid modeling shows that the average length of S2 tethers along the thick filament (except near the tapered ends) is approximately 10 nm, or 16% of S2's total length, with an angular range encompassing 90 degrees axially and 120 degrees azimuthally. The large range of S2 angles indicates that some rigor bridges produce positive force that must be balanced by others producing drag force. The short tethering segment clarifies constraints on the function of S2 in accommodating variable myosin head access to actin. We suggest that the short length of S2 may also favor intermolecular head-head interactions in IFM relaxed thick filaments.

Oral administration of 10% solution of Phytomix-40 (multicomponent plant phytoadaptogen) to C57Bl/6 mice with MPTP-induced Parkinson's syndrome alleviated symptoms (oligokinesia and muscle rigidity), compensated for the deficiency of dopamine and its metabolites (DOPAC and homovanillic acid), and reduced the level of lipid peroxides in the striatum. In vitro Phytomix-40 in a concentration of 3.3 x 10(-2) g/liter exhibited a pronounced antioxidant effect (5-fold decreased MDA level in mouse brain homogenate in Fe(2+)-ascorbate-dependent LPO).

The phenol 2,6-di-tert-butyl-4-nitrophenol (DBNP) is a contaminant found onboard submarines and is formed by the nitration of an antioxidant present in turbine lubricating oil TEP 2190. DBNP has been found on submarine interior surfaces, on eating utensils and dishes, and on the skin of submariners. DBNP exposure is a potential health concern because it is an uncoupler of mitochondrial oxidative phosphorylation. Adult male rats were dosed once by oral gavage with 15 or 40 mg/kg DBNP mixed with 14C-DBNP in kanola oil and 0.8% v/v DMSO (n = 16/group). The distribution of 14C in major tissues was measured over time for up to 240 h post-dose. Unexpectedly, 6/16 (40%) of the rats gavaged with 40 mg/kg DBNP died within 24 h of dosing. Prostration, no auditory startle response, reduced locomotor activity, and muscular rigidity persisted in survivors for up to 8 days after dosing. For animals dosed with 15 mg/kg DBNP, radioactivity levels were significantly elevated in the following tissues 24h after dosing: fat>>>liver>kidneys>heart>lungs>brain>striated muscle>spleen. Radioactivity levels were elevated for fat, liver, kidney, heart, and lungs of animals euthanized 144 h post-dosing and in the liver of animals euthanized 240 h post-dosing. These findings suggest that DBNP may accumulate in the body as a result of continuous or repeat exposures of short interval to DBNP.

A 42-year-old, left-handed woman first noted impaired dexterity of the dominant hand, soon followed by dysarthria and cognitive decline. Over a 4-year period, she developed severe left-sided apraxia with eventual neglect of the left arm and progressive extrapyramidal signs. Cognitive testing showed progressive executive, visuospatial, fluency, and naming impairment with relative preservation of memory. Single-photon emission computed tomography demonstrated asymmetric right posterior frontal and superior parietal hypoperfusion. The clinical impression was corticobasal degeneration. At autopsy, severe atrophy was seen in the perirolandic and frontal regions. There was marked neuronal loss and gliosis in the posterior frontal and precentral regions and less severe pathology in prefrontal, temporal, and parietal areas. Mild to moderate gliosis and neuronal loss were also seen in the putamen, globus pallidus, subthalamic, and dentate nuclei. Gallyas silver stain revealed numerous inclusions adjacent to oligodendrocyte nuclei in white and gray matter of affected cortical and subcortical regions. The gracile inclusions were wavy, slender, and stained positively with antibodies to ubiquitin and alphaB-crystallin but not to microtubule-associated proteins (tau, MAP1B, MAP2), tubulin, neurofilaments, glial fibrillary acidic protein, or alpha-synuclein. The argyrophilic inclusions identified in this case are distinct from those previously described in neurodegenerative diseases., (Copyright 2005 Movement Disorder Society.)

Dysferlinopathy and rigid spine syndrome occurring in a 50-year-old man is reported. The patient noticed stiffness of knee and ankle joints, which gradually extended to neck, wrist and elbow joints leading to difficulty in anterior flexion. Muscular weakness and wasting of the lower extremities had developed since age 40, accompanied by a limitation of anterior bending of the spine. Elevated serum CK was noticed. Muscle CT revealed atrophy with moderate fatty replacement of muscles in the neck, shoulder and pelvic girdle, and marked replacement in the para-vertebral muscles, posterior compartment of hamstrings and calf muscles. Electromyography showed a typical myogenic pattern, and muscle biopsy disclosed dystrophic changes, compatible with limb-girdle muscular dystrophy 2B. Loss of dysferlin expression was verified by immunohistochemistry, which was confirmed by a mini-multiplex Western blotting system. Gene analyses of the dysferlin gene disclosed compound heterozygotes for frameshift (G3016 + 1A) and a missense mutation (G3370T). This study might propose some clues to resolve the combination of musular dystrophies and rigid spine syndrome.

The motor mechanisms of a patient with unilateral hand clumsiness in the early stages of akinetic-rigid syndrome were assessed by functional magnetic resonance imaging (fMRI). Movements of the unaffected hand produced activation in the contralateral sensorimotor cortex (SMC) and ipsilateral SMC and superior parietal lobule (SPL). The affected hand activated the bilateral SMCs, supplementary motor areas, and SPLs. We speculated that the bilateral activation indicated recruitment of a pre-existing bilaterally organized large-scale neural network to perform the motor task.

Background: Spinocerebellar ataxia type 17 is an autosomal dominant cerebellar ataxia caused by a CAG repeat expansion in the TATA box-binding protein gene. Ataxia is typically the first sign whereas behavioral symptoms occur later., Objective: To characterize the unusual phenotypic expression of a large spinocerebellar ataxia type 17 kindred., Design: Clinical, neuropathological, and molecular genetic characterization of a 4-generation family with 16 affected patients., Results: Behavioral symptoms and frontal impairment dominated the early stages preceding ataxia, rigidity, and dystonic movements. Neuropathological examination showed cortical, subcortical, and cerebellar atrophy. Purkinje cell loss and gliosis, pseudohypertrophic degeneration of the inferior olive, marked neuronal loss and gliosis in the caudate nucleus, and in the medial thalamic nuclei were salient features together with neuronal intranuclear inclusions stained with anti-TATA box-binding protein and antipolyglutamine antibodies. The disease was caused by a stable 52 CAG repeat expansion of the TATA box-binding protein gene, although there was apparent variability in the age of onset., Conclusion: The characteristics of this family broaden the clinical picture of spinocerebellar ataxia type 17: initial presenile dementia with behavioral symptoms should be added to ataxia, rigidity, and dystonic movements, which are more commonly encountered.

Introduction: In Wilson's disease (WD), brain magnetic resonance images (MRI) show increased signal intensity in T2 weighted images in the lenticular nuclei, thalamus and brainstem, including the substantia nigra. A poor therapeutic response to levodopa in WD suggests the mechanism of a postsynaptic abnormality. However positron emission tomography studies show an involvement of the nigrostriatal presynaptic dopaminergic pathway., Case Report: We report the clinical manifestations in a case of WD with akinetic-rigid syndrome and initial hesitation. The brain MRI showed an increased signal intensity lesion in the substantia nigra region, in addition to basal ganglion and thalamic lesions. However, dopamine transporter (DAT) imaging with 99mTc-TRODAT-1 revealed a nonsignificantly increased DAT uptake, suggesting a normal presynaptic nigrostriatal dopaminergic terminal., Conclusion: We suggest that significant heterogeneity can be found in WD patients and a normal presynaptic dopaminergic pathway may occur in some patients, even those with typical akinetic-rigid syndrome and evidence of substantia nigra involvement in the brain on MRI.

In order to study neuronal death in Parkinson's disease, neurons of the substantia nigra, pars compacta in rats were exposed to elevated levels of glutamate and decreased levels of energy in vivo and consequences for behavior and neuronal morphology were studied. Thus, repeated local injections (9x) of the glutamate uptake inhibitor L- threo-hydroxyaspartate (L-THA; 833 microM in 0.3 microl) in the presence or absence of the succinate dehydrogenase inhibitor malonate (25 mM in 0.3 microl) were applied during three weeks. 24 h after injection, rigidity and catalepsy were measured, as well as, at the end of the three week period, locomotion, rearing and exploratory behavior. Thereafter, the cytoarchitecture of the substantia nigra, pars compacta of the brains of these rats was described. The L-THA plus malonate injected rats did not differ in their behavior from carrier injected rats, except for rigidity: their scores were higher than that of carrier and L-THA injected rats (P < 0.05), while L-THA injected rats did not differ from carrier injected controls. Observations on cresyl violet sections revealed, that, although many neurons with a shrunken nucleolus and faintly stained cytoplasm were present in both L-THA and L-THA plus malonate treated rats, the ventral edge of the substantia nigra, pars compacta containing modified cells was longer in L-THA plus malonate than in L-THA injected rats (P < 0.05). This indicates, that a minimum amount of damage to neurons in the ventral part of the substantia nigra, pars compacta might be required for the expression of rigidity.

Diagnosis criteria of stiff-person syndrome (SPS) include progressive, fluctuating muscular rigidity and spasms with normal neurological examination. The presence of unusual features such as prominent limb rigidity with segmental signs and contracture, evidence of brainstem dysfunction, profound autonomic disturbances, CSF pleiocytosis or MRI abnormalities in patients with SPS presentation allows to classify these patients as progressive encephalomyelitis with rigidity (PER). We report a 50 year-old woman suffering from severe painful spasms of abdominal wall and limb muscles. Neurological examination showed pyramidal signs. EMG disclosed continuous muscle activity with superimposed discharges. Treatment with high doses of diazepam and baclofen led to moderate improvement of generalised stiffness. However, the right arm became more rigid with oedema and vasomotor changes. Subsequently, bilateral nystagmus and internuclear opthalmplegia appeared. There was mild CSF pleiocytosis. Associated auto-immune thyroiditis was found with positive anti-microsome antibodies and decreased thyroid hormones. Search for profound neoplasm was negative. The patient had three subacute bouts then she improved with methylprednisolone. The initial clinical presentation mimicking a SPS with subsequent diffuse involvement of the central nervous system and a striking localisation of a severe rigidity to one arm allowed to suspect the diagnosis of PER. The relationship between SPS and PER remains unclear because of the rarity of these disorders. The observation reported in this paper gives evidence that both the disorders are probably two clinical presentations of the same pathogenic process.

Rigid spine syndrome is a neuromuscular disorder characterised by early rigidity of the spine due to axial muscle contractures, generally associated with muscle weakness, limb-joint contractures, and often respiratory failure. This phenotype may be associated with several muscular diseases. In cases of merosin-positive congenital muscular dystrophies (CMD) with rigid spine syndrome, we have recently identified a new locus (RSMD1) on chromosome 1p35-36. In the present study, we report the clinical, morphological and genetic analysis of other patients affected by a CMD with rigid spine syndrome from nine consanguineous families. Homozygosity mapping showed that the disease was linked to RSMD1 in one of the nine families. The other families were excluded from RSMD1, and the patients presented highly variable phenotypes suggesting the involvement of more than one gene defect in rigid spine syndrome. Nevertheless, a subgroup of patients who never walked, and had very early rigidity of the spine and scoliosis, may be considered for further genetic analysis.

Ophthalmoplegia is rarely reported in patients with amyotrophic lateral sclerosis (ALS). We describe a patient with sporadic ALS, who had developed progressive external ophthalmoplegia of supranuclear origin and rigidity in the neck. Autopsy findings showed histopathological abnormalities consistent with ALS. In addition to these findings, there was neuronal loss and gliosis in the putamina and globi pallidi, and gliosis in the periaqueductal gray matter. Our case appears to raise the possibility that ALS comprises a heterogenous group of disorders.

The present study was conducted to determine if the full array of parkinsonian symptoms could be detected in rats with nigrostriatal cell loss and striatal dopamine depletions similar to levels reported in the clinical setting, and to determine if older rats exhibit more robust parkinsonian deficits than younger rats. Young (2 months old) and middle-aged (12 months old) rats received bilateral striatal infusions of 6-OHDA, over the next 3 months they were assessed with a battery of behavioral tests, and then dopaminergic nigrostriatal cells and striatal dopamine and DOPAC levels were quantified. The results of the present study suggest that: (1) the full array of parkinsonian symptoms (i.e. akinesia, rigidity, tremor and visuospatial cognitive deficits) can be quantified in rats with incomplete nigrostriatal dopaminergic cell loss and partial reductions in striatal dopamine levels (2) parkinsonian symptoms were more evident in middle-aged rats with 6-OHDA infusions, and (3) there was evidence of substantial neuroplasticity in the older rats, but regardless of the age of the animal, endogenous compensatory mechanisms were unable to maintain striatal dopamine levels after rapid, lesion-induced nigrostriatal cell loss. These results suggest that using older rats with nigrostriatal dopaminergic cell loss and reductions in striatal dopamine levels similar to those in the clinical condition, and measuring behavioral deficits analogous to parkinsonian symptoms, might increase the predictive validity of pre-clinical rodent models.

Unlabelled: Rigid spine syndrome is characterized by massive spinal rigidity, usually most marked in the cervical region. Stiffness of the peripheral joints is sometimes present. We report two cases. Patient 1 was a 12-year-old boy diagnosed at three years of age with Duchenne's muscular dystrophy because of delayed onset of walking. Contracture of the Achilles tendons, flexion contracture of the elbows, and loss of motion of the cervical spine were the main findings during the current evaluation. Radiographs of the affected joints were normal. An electrocardiogram showed an incomplete left bundle branch block. Muscle enzyme activities were moderately elevated. A myopathic pattern was seen on the electromyogram. A muscle biopsy showed muscle fiber atrophy with peri- and endomysial fibrosis. Patient 2 was a 39-year-old man with a five-year history of isolated rigidity of the cervical spine thought to be due to a spondylarthropathy. Extension was the only movement possible at the cervical spine. The peripheral joints showed no motion range limitation. Findings were normal from radiographs of the spine and sacroiliac joints, an erythrocyte sedimentation rate determination, an electromyogram, and muscle enzyme activity assays. A muscle biopsy showed muscle fiber atrophy with peri- and endomysial fibrosis., Discussion: Rigid spine syndrome is rare in rheumatological practice and can simulate a number of other muscle and joint diseases. Peri- and endomysial fibrosis may be strongly suggestive, although nonpathognomonic. Involvement of the heart governs the prognosis.

Marchiafava-Bignami disease (MBD) was diagnosed in a malnourished 43-year-old patient with chronic alcoholism, severe generalized extrapyramidal rigid syndrome, and severe dyspraxia. Cranial CT and MRI demonstrated isolated lesions in the geno and splenium of the corpus callosum (CC) characteristic for MBD. On thiamine therapy, a slow but steady recovery of clinical symptoms occurred, and serial CT and MRI studies demonstrated marked reversibility of abnormalities in the CC. Besides clinical improvement with a good functional outcome, reversal of CT and MRI abnormalities may occur in MBD.

A case of progressive encephalomyelitis with rigidity (PEWR) associated with hepatitis C virus (HCV) is reported. A 58 year-old woman presented with a clinical picture of progressive quadriparesis, sensory loss, sphincter dysfunction, painful muscle spasms in the upper and lower limbs and continuous muscle unit activity in electromyography. She developed hepatitis, pancreatitis and HCV-RNA was detected in the plasma by reverse transcription-polymerase chain reaction (RT-PCR). Postmortem histopathological examination showed encephalomyelitis with perivascular lymphocyte cuffing, infiltration and neuronal loss mainly affecting the brainstem and cervical spinal cord. The RT-PCR analysis of the postmortem brain, brainstem, liver, pancreas, plasma and CSF samples revealed the presence of HCV genome in all specimens except CSF. Clinical features, postmortem histopathology and PCR results and the possible etiopathogenesis of PEWR are briefly discussed.

A 41-year old caucasian male presented with limited range of motion of the entire spine and myogenous intermittent claudication. He was referred with the diagnosis "ankylosing spondylitis". The clinical picture mimicked ankylosing spondylitis, but there were no corresponding radiological abnormalities despite a 13-year history of his disease. Laboratory values showed markedly elevated levels of muscle enzymes. The diagnosis of rigid spine syndrome, a subtype of muscular dystrophy, was made from the clinical picture a normal EMG and degenerative changes on a biopsy from the muscle trapezius. We would like to draw attention to this rare cause of back pain.

Patients with AIDS dementia complex (ADC) appear to have an increased likelihood of developing acute onset parkinsonism and dystonia when treated with dopamine antagonists. It has been hypothesized, based on clinical evidence, that hypersensitivity to these drugs in ADC is probably related to direct invasion of the basal ganglia by the HIV virus and a secondary alteration in dopaminergic mechanisms. We report the first pathological description of a patient with ADC who developed acute onset, generalized rigidity and dystonia after a brief trial of low dose neuroleptic therapy administered for psychotic symptoms. An unusual clinical feature of this case was the persistence of his movement disorder. Pathological examination revealed a generalized encephalitic process with substantial neuronal loss observed primarily in the medial and lateral globus pallidus. Correlation with a current model of basal ganglia pathophysiology and other disorders with pallidal lesions is discussed. Clinical and pathological features of this case confirm the previous contention and indicate that dopamine antagonists should be utilized with extreme caution in patients with ADC.

Over the last 5 years the Pediatric Neurology service at King Faisal Specialist Hospital and Research Centre (KFSH&RC) has seen 131 infants and children with movement disorders. Forty-nine (37%) had identifiable biochemical defects, 25 of which were organic acidemias. Nineteen of 29 patients with dystonia had organic acidemias, primarily glutaric aciduria type 1 (7 patients), bilateral striatal necrosis (4 patients), and 3-methyl glutaconic aciduria (3 patients). All patients with parkinsonian rigidity (n = 11) had organic acidemias; again, the greatest number accounted for by glutaric aciduria type 1 (7 patients), who had both parkinsonian rigidity combined with dystonia. Myoclonus occurred in only 1 of 25 and chorea in 7 of 25 patients with organic acidemias. At the least all patients had bilateral lesions of putamen and head of caudate, seen best in MRI brain scans as increased T2 signal intensities with normal volume, and later with volume loss.

Neuropathological studies show that about 20% of all patients suffering from an acinetic-rigid syndrome can not be given the diagnosis of idiopathic Parkinson's disease. Among these non-idiopathic Parkinson-syndromes the corticobasal degeneration (CBD) can be regarded as a separate disease entity. The pathological findings of moderate predominantly frontal and parietal cerebral atrophy, cortical Pick-cells and specific corticobasal inclusion bodies are considered valuable features which support the diagnosis. The clinical Characteristics of CBD are demonstrated in 3 patients including an acinetic-rigid syndrome, limb apraxia and "alien limb"-syndrome, as well as reflex myoclonus. Eye movement disorders, dementia and other rare symptoms may also be present. Electrophysiological reflex-testing helps to corroborate diagnosis. These findings and a summary which includes the previously published cases of CBD show that CBD in most cases can be diagnosed intra vitam.

Background: Controversy exists regarding the definition of masseter muscle rigidity (MMR) and anesthetic management after MMR. This study reports current anesthetic management after MMR, estimates the incidence of clinical malignant hyperthermia (MH) in patients with MMR, and is the first to evaluate the coincidence of MMR with malignant hyperthermia susceptibility (MHS) according to the 1987 North American Malignant Hyperthermia Group protocol., Methods: Practicing anesthesiologists referred pediatric patients for biopsy between 1986 and 1991 based on evidence of MMR after succinylcholine (1975-1991). The clinical scenario was described as MMR alone or MMR followed by signs of MH, including arterial CO2 tension > 50 mmHg, arterial pH < or = 7.25, and base deficit > 8. Patients had caffeine-halothane muscle contracture testing to determine MHS., Results: Seventy patients (50 boys and 20 girls) were evaluated. Eighty-three percent (58 of 70) of anesthetics were halothane-succinylcholine. In 68% (48 of 70) of cases, the anesthetic was discontinued, whereas anesthesia was continued with nontriggering agents in 11% (8 of 70) and with triggering agents in 13% (9 of 70). Fifty-nine percent (41 of 70) of patients were diagnosed as MHS by muscle biopsy. In 7% (5 of 70) of patients, clinical MH developed within 10 min of MMR., Conclusions: This study, by using the current North American Malignant Hyperthermia Group protocol, reaffirms the high incidence (59%, 41 of 70) of MHS associated with MMR as confirmed by muscle biopsy. Of the MHS patients, 5 developed signs of clinical MH. Most anesthesiologists in this study, when confronted with MMR, discontinued anesthesia. Because of the potential lethality of MH and the > 50% concordance between MMR and MHS, the most conservative course of action after MMR is to discontinue the anesthetic and observe the patient for clinical evidence of MH. An acceptable alternative, depending on the urgency of the surgery, would be to continue anesthesia with nontriggering agents for MH, with appropriate monitoring.

A 13-year-old HIV-infected girl presented with a rapidly progressive akinetic-rigid syndrome. Cranial magnetic resonance imaging revealed bilateral centrum semiovale lesions extending into the basal ganglia. Detailed histopathological study of a biopsy specimen from the involved regions resulted in a diagnosis of progressive multifocal leukoencephalopathy (PML). This case illustrates that an akinetic-rigid syndrome may be a rare presentation of PML. HIV-related PML may have unusual radiological features. Brain biopsy may be necessary to confirm PML in cases associated with atypical clinical and radiological presentations.

The Leksell Gamma Knife is a useful and safe method to perform thalamotomy and pallidotomy in selected older patients with Parkinson's disease and related movement disorders. In this preliminary report, 2 of 3 patients with severe intention tremor were relieved of their symptoms by thalamotomy, as were 4 of 7 patients with Parkinson's tremor. Four of 8 patients had significant improvement of contralateral rigidity following pallidotomy.