The Role of Muscle Strength in the Sit-to-Stand Task in Parkinson's Disease

Background

Rising from a chair or the sit-to-stand (STS) task is frequently impaired in individuals with Parkinson's disease (PD). These patients commonly attribute such difficulties to weakness in the lower extremities. However, the role of muscle strength in the STS transfer task has not been fully elucidated.

Objective

We aim at determining the role of muscle strength in the STS task.

Methods

We studied 90 consecutive patients with PD and 52 sex- and age-matched controls. Lower limb strength was determined in both legs by clinical examination using the Medical Research Council Scale, dynamometric (leg flexion) and weighting machine (leg pressure) measures. Patients were interrogated regarding the presence of subjective lower limb weakness or allied sensations.

Results

There were 20 patients (22.2%) with abnormal STS task (item 3.9 of the MDS-UPDRS-III ≥2 points). These patients had higher modified Hoehn and Yahr stage (P  <  0.001) and higher total motor scores of the MDS-UPDRS(P  <  0.001), compared with 70 PD patients with normal STS task. Patients with abnormal STS task endorsed lower limb weakness more frequently and had lower muscle strength in the proximal lower extremities, compared to PD patients with normal STS task and normal controls. The presence of perceived lower limb weakness increased the risk of an abnormal STS task, OR: 11.93 (95% C.I. 1.51-94.32), whereas a hip extension strength ≤9 kg/pressure also increased the risk of abnormal STS task, OR: 4.45 (95% C.I. 1.49-13.23). In the multivariate regression analysis, bradykinesia and decreased hip strength were related to abnormal STS task.

Conclusions

Patients with PD and abnormal STS task complain more commonly of lower limb weakness and have decreased proximal lower limb strength compared to patients with PD and normal STS task, likely contributing to abnormalities in performing the STS task.

Contrasting features between Tourette syndrome and secondary tic disorders

Tics are rapid, recurrent, non-rhythmic movements or emitted sounds. Tics are the hallmark of Tourette syndrome (TS); however, a number of other disorders may be associated with tics, so-called secondary tic disorders (STD). We assessed clinical history and performed blinded evaluations of video-recordings from patients with TS and STD in order to identify features that may differentiate tics associated with TS vs STD. There were 156 patients with TS and 38 with STD, 21 of whom had functional (psychogenic) tics. Patients with TS were more frequently male and had a younger age at onset. Tics in TS tend to involve muscles in the cranial-cervical area more often and have greater severity and complexity than those in patients with STD. Similar findings were observed when contrasting patients with TS with patients with functional tics only. Simple phonic tics showed the greatest diagnostic accuracy for TS, compared with STD, but marked overlap in the types of tics and comorbidities was observed between patients with TS and STD. Patients with TS were more likely males, had a younger age at onset, phonic tics and motor tics affecting predominantly the head and neck area, and had a greater complexity and severity of tics than those with STD. When these features are absent a consideration should be given to the possibility of a tic disorder other than TS.

Oromandibular tics associated with Tourette syndrome

BACKGROUND

Tourette syndrome (TS) is the most common cause of chronic tics. Patients with TS frequently manifest motor tics involving the eyes and face but oromandibular (OM) tics have been rarely studied.

MATERIALS AND METHODS

We reviewed the medical records and video-recordings of 155 consecutive patients with TS in our movement disorders clinic. In addition, we studied 35 patients with classic tardive dyskinesia (TD) and compared their clinical and demographic features with those with TS.

RESULTS

We identified 41 patients with OM tics (26.5%). Although patients with OM tics had a greater overall tic severity and higher frequency of.complex motor and phonic tics, in the bivariate analysis, only comorbid dystonic tics (P = 0.001), greater number of affected body parts (P = 0.012) and more frequent eye-rolling tics (P = 0.059) were included in the final regression model after controlling for other variables. When compared with patients with OM tics, patients with classic TD had more frequently masticatory movements (sensitivity, 0.86; specificity, 0.95), continuous tongue movements (sensitivity, 0.71; specificity, 1.0) and continuous OM movements (sensitivity, 0.4; specificity, 1.0).

CONCLUSIONS

OM tics are common and often troublesome or even disabling symptoms in patients with TS. They may be difficult to differentiate from TD, but the latter is typically manifested by continuous orolingual and masticatory movements.

Objective and self-perceived lower limb weakness in Parkinson's disease

BACKGROUND

Lower limb weakness is a long-recognized symptom in patients with Parkinson's disease (PD), described by James Parkinson in his seminal report on 'paralysis agitans'. However, little is known on the frequency, clinical correlations, and association with objective decrease in muscle strength in such patients.

OBJECTIVE

The objective of this study was to assess the frequency of objective and perceived lower limb weakness in patients with PD.

METHODS

We studied 90 consecutive patients with PD and 52 age-matched controls. We recorded clinical and demographic variables, as well as perceived weakness and allied abnormal lower limb sensations, including 'heavy legs', 'fatigued legs', and 'pain'. Symptoms consistent with restless legs syndrome were not considered. Lower limb strength was determined in both legs by means of the Medical Research Council scale, dynamometric (leg flexion) and weighting machine (leg pressure) measures.

RESULTS

Weakness and allied abnormal lower limb sensations were reported in 69% of patients with PD and 21% of healthy controls. Patients with PD had decreased leg pressure compared with healthy controls (p = 0.002). Among patients with PD, an association between perceived leg weakness (and allied sensations) and gait freezing (p = 0.001) was observed in the multivariate regression analysis; however, these variables only explained 30.4% of the variance. Moreover, PD patients with and without abnormal lower limb sensations had similar muscle strength by objective measurements.

CONCLUSION

Perceived lower limb weakness and allied abnormal sensations are common in patients with PD. However, there is a dissociation between perceived weakness and objective muscle strength in the lower limbs. These abnormal sensations were mostly related to gait freezing but a causal association is questionable.

Self-injurious behavior in Tourette syndrome

INTRODUCTION

Tourette syndrome (TS) is characterized by the presence of motor and phonic tics, as well as a variety of behavioral co-morbidities. Self-injurious behavior (SIB) is one of the most serious manifestations of TS, but its pathophysiology is poorly understood.

METHODS

Consecutive patients with TS studied in a tertiary care center.

RESULTS

We identified a total of 34 patients (16.9%) with SIB from a cohort of 201 patients with TS. Most of these patients (n = 23, 11.4%) experienced self-directed damage; while others had outward-directed (n = 7, 3.5%) or tic-related SIB (n = 4, 2%). Compared to other patients with TS, those who manifested SIB (self- and outward-directed damage) were more likely to have tics involving shoulder (P = 0.046), trunk (P = 0.006), and arm (P = 0.017); as well as dystonic tics (P = 0.016); complex motor tics (P < 0.001), copropraxia (P = 0.045), complex phonic tics (P = 0.003), higher number of phonic tics (P = 0.001), verbalizations (P = 0.001), coprolalia (P = 0.006) and obsessive compulsive disorder (OCD) (P < 0.001) as determined by bivariate analysis. In the multivariate analysis only complex motor tics (P = 0.006), obsessive-compulsive behavior (P = 0.025) and greater severity of tics (P = 0.002) showed a statistically significant association with SIB. Patients with SIB had a greater probability of being selected for deep brain stimulation (DBS) therapy by the treating clinician (P = 0.01).

CONCLUSIONS

SIB is observed in about 17% of patients with TS. The presence of complex motor tics, OCD and greater severity of tics was related to the presence of SIB.

Intestinal Decontamination Therapy for Dyskinesia and Motor Fluctuations in Parkinson's Disease

Parkinson's disease is neurodegenerative disorder with an initial robust response to levodopa. As the disease progresses, patients frequently develop dyskinesia and motor fluctuations, which are sometimes resistant to pharmacological therapy. In recent years, abnormalities in gut microbiota have been identified in these patients with a possible role in motor manifestations. Dysbiosis may reduce levodopa absorption leading to delayed “On” or “no-On” states. Among 84 consecutive patients with PD, we selected 14 with levodopa-induced dyskinesia and motor fluctuations with a Movement Disorders Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part IV ≥ 8 points following a trial of pharmacological adjustment 2–3 months prior to study enrollment or adjustments in deep brain stimulation therapy. Patients received treatment with sodium phosphate enema followed by oral rifaximin and polyethylene glycol for 7 and 10 days, respectively. Evaluations between 14 to 21 days after starting treatment showed improvement in MDS-UPDRS-IV (P = 0.001), including duration (P = 0.001) and severity of dyskinesia (P = 0.003); duration of medication “Off”-state (P = 0.004); functional impact of motor fluctuations (P = 0.047) and complexity of motor fluctuations (P = 0.031); no statistical improvement was observed in “Off” dystonia (P = 0.109) and total motor scores (P = 0.430). Marked to moderate improvement in dyskinesia was observed in 57% of cases with blinded evaluation of videos. About 80% of patients perceived moderate to robust improvement at follow-up. A therapeutic strategy aimed at decontamination of intestines showed benefit in motor fluctuations and dyskinesia. Further studies should confirm and clarify the mechanism of improvement observed in these patients.

Functional gait disorders, clinical phenomenology, and classification

BACKGROUND

Functional gait disorders (FGDs) are relatively common in patients presenting for evaluation of a functional movement disorder (FMD). The diagnosis and classification of FGDs is complex because patients may have a primary FGD or a FMD interfering with gait.

METHODS

We performed a detailed evaluation of clinical information and video recordings of gait in patients diagnosed with FMDs.

RESULTS

We studied a total of 153 patients with FMDs, 68% females, with a mean age at onset of 36.4 years. A primary FGD was observed in 39.2% of patients; among these patients, 13 (8.5%) had an isolated FGD (a gait disorder without other FMDs). FMDs presented in 34% of patients with otherwise normal gait. Tremor was the most common FMD appearing during gait, but dystonia was the most common FMD interfering with gait. Patients with FGD had a higher frequency of slow-hesitant gait, astasia-abasia, bouncing, wide-based gait and scissoring compared with patients with FMDs occurring during gait. Bouncing gait with knee buckling was more frequently observed in patients with isolated FGD (P = 0.017). Patients with FGDs had a trend for higher frequency of wheelchair dependency (P = 0.073) than those with FMDs interfering with gait.

CONCLUSIONS

Abnormal gait may be observed as a primary FGD or in patients with other FMDs appearing during gait; both conditions are common and may cause disability.

The frequency and diagnostic accuracy of hand deformities in Parkinson's disease

Hand deformities are well-known abnormalities observed in patients with Parkinson's disease (PD). We determined the frequency and diagnostic accuracy of hand deformities in PD. We studied 44 consecutive patients with PD, 44 age- and gender-matched normal controls and 22 patients with essential tremor (ET). By means of photographs taken in both hands of all participants, the degree of metacarpophalangeal (MCP) joint flexion was quantified by software and by blinded evaluations using a semiquantitative scale from the radial aspect, we grouped hands into four grades. The presence of classical striatal hand deformity (CSHD), defined as MCP joint flexion, proximal interphalangeal joint extension and distal interphalangeal joint flexion was also evaluated. Patients with PD had a higher frequency of MCP joint flexion and CSHD compared to normal controls and patients with ET. Mean MCP joint flexion was higher in both hands in patients with PD: 20.8° vs. normal controls (3.3°-3.9°) and patients with ET (2.8°-6.3°), P = 0.001. Concordance between evaluators for MCP joint flexion was fair: κ = 0.34 (P < 0.001), but poor for CSHD: κ = 0.142-0.235 (P < 0.05). A right hand MCP joint flexion of 12.5° and left hand of 10.5°, showed similar sensitivity (0.70) and specificity (between 0.75 and 0.80) than any degree of MCP joint flexion for the diagnosis of PD. CSHD had a sensitivity (0.60-0.80) and specificity (0.78-0.98) for the diagnosis of PD. Hand deformities are commonly observed in patients with PD, they may aid in the diagnosis of PD when compared to normal controls and patients with ET.

Distinguishing features between valproate-induced tremor and essential tremor

BACKGROUND

Tremor frequently occurs in patients taking valproate and may resemble that observed in patients with essential tremor (ET). We aimed to compare the distribution, severity, and functional impact of both types of tremor.

METHODS

Among 118 consecutive individuals taking valproate, we identified 28 patients with valproate-induced tremor severe enough to require pharmacological treatment; through evaluations using the Clinical Rating Scale for Tremor (CRST), they were compared with 29 consecutive patients with ET.

RESULTS

Patients with valproate-induced tremor were significantly younger than those with ET: 35.6 ± 15.4 vs 58.8 ± 20.5 years (P < .001), with a shorter evolution time of tremor (P < .001). Total CRST scores did not differ between groups (P = .164), neither in subscores of Parts A (P = .321), B (P = .094), and C (P = .386). Patients with valproate-induced tremor had a higher proportion of postural tongue tremor compared with ET patients: 22 (79%) vs 15 (52%) (P = .034). A frank tremor axis in the Archimedes spirals was observed in a higher proportion of patients with ET compared to valproate-induced tremor: 31% vs 3.6% (P = .006).

CONCLUSIONS

Patients with valproate-induced tremor requiring pharmacological treatment have similar distribution, CRST scores, and functional impact than those with ET.

Vertical nystagmus associated with glutamic acid decarboxylase antibodies responding to cyclophosphamide

Several neurological disorders have been described in patients with autoimmunity associated with GAD antibodies. Among these disorders, nystagmus and oculomotor dysfunction are increasingly recognized, although they have been rarely reported isolated or as the main manifestation of anti-GAD autoimmunity. Moreover, therapeutic approaches for such patients are unclear. Here we present a 44-year-old man with disabling oscillopsia secondary to downbeat nystagmus, abnormal saccades, ocular pursuit and optokinetic nystagmus, as well as mild gait ataxia and cerebellar atrophy associated with high serum GAD antibodies with intrathecal secretion of such antibodies. The patient did not have clinical benefit with plasma exchange, but had a robust symptomatic improvement with cyclophosphamide. We discuss the possible pathogenic role of GAD antibodies in nystagmus and the role of immunotherapy in these patients.

The clinical features and functional impact of valproate-induced tremor

BACKGROUND

Tremor is a known side-effect of anticonvulsants, particularly of valproate. However, there is a dearth of information regarding detailed clinical features and functional impact of valproate-induced tremor.

METHODS

We studied a cohort of patients treated with anticonvulsants for neurological disorders, through blinded evaluations using the Clinical Rating Scale for Tremor (CRST); we compared the frequency, severity and functional impact of drug-induced tremor between patients treated with valproate and those treated with other anticonvulsants.

RESULTS

From a cohort of 218 consecutive patients, 171 were fully evaluated; 118 patients were taking valproate alone or combined with other anticonvulsants and 53 patients were taking other anticonvulsants. Mean age (±SD) at evaluation of the cohort was 32 ± 13 years, females represented 55.6% of cases. Tremor was more frequently observed in patients taking valproate particularly postural upper limb tremor: 49% vs. 15% (right-side) (P < 0.001) and 48.3% vs. 13.2% (left-side), (P < 0.001); had a higher total CRST score: 12.14 vs. 3.06 (P < 0.001), and required more frequently treatment for drug-induced tremor: 23.7% vs. 5.6% (P=0.005) compared with patients taking other anticonvulsants. Among 118 patients taking valproate, women had a higher total CRST score compared with men: 14.54 ± 14.9 vs. 9.56 ± 9.55 (P=0.034). A weak correlation between the total CRST score, dose per Kg of valproate and serum levels of valproate were observed.

CONCLUSIONS

Tremor is frequently observed in patients taking valproate and is severe enough to require treatment in about 24% of cases.

Cerebellar disease associated with anti-glutamic acid decarboxylase antibodies: review

Several neurological syndromes have been recognized associated to GAD antibodies. Among those disorders, cerebellar ataxia (CA) is one of the most common, along with stiff-person syndrome. Patients with GAD associated CA present with a progressive pancerebellar syndrome, with a subacute or chronic evolution, along with other neurological manifestations such as stiffness, oculomotor dysfunction, epilepsy, and cognitive dysfunction. These symptoms may be preceded by the so-called "brainstem attacks", where manifestations consistent with transient dysfunction of the brainstem may be observed. These patients frequently have extra-neurologic autoimmune manifestations such as diabetes mellitus type 1, polyendocrine autoimmune syndrome, pernicious anemia, vitiligo, etc. A proportion of patients may present with an underlying neoplasia, but the course is less aggressive than in those patients with classical paraneoplastic CA with onconeural antibodies. The diagnosis is based on the present of high serum and CSF titers of GAD antibodies, with intrathecal production of such antibodies. Treatment is aimed to decrease the immunological response with intravenous immunoglobulin, steroids, rituximab and oral immunosuppressive drugs. A subacute presentation and rapid initiation of immunotherapy seem to be the predictors of a favorable clinical response.