Analysis of SCA8, SCA10, SCA12, SCA17 and SCA19 in patients with unknown spinocerebellar ataxia: a Thai multicentre study

BACKGROUND

About 50 % of Thai patients with adult-onset spinocerebellar ataxia (SCA) was Machado-Joseph disease (MJD), SCA1, SCA2 and SCA6. The author investigated further on less common SCAs in the patients without any known mutations.

METHODS

DNA samples of 82 index patients who were genetically excluded MJD, SCA1, SCA2, SCA6, SCA7 and dentatorubro-pallidoluysian atrophy (DRPLA) were examined. Analysis of SCA8, SCA10, SCA12, SCA17 and SCA19 genes were comprehensively performed. Normal range of trinucleotide repeat expansion sizes of TATA-box-binding protein gene (TBP) were also determined in 374 control subjects.

RESULTS

Eight patients carried ≥42 CAG/CAA repeat allele in the TBP consistent with SCA17. The pathological repeat alleles ranged from 42 to 57 repeats. All patients had significant degree of cognitive dysfunction. Other non-ataxic phenotypes comprised of parkinsonism, chorea, dystonia and myoclonus. A sporadic patient carried a heterozygous 41-repeat allele developed chronic progressive cerebellar degeneration commenced at the age of 28 years. Whilst, 2 % of the control subjects (8/374) carried the 41-repeat allele. Five of the carriers were re-examined, and revealed that four of them had parkinsonism and/or cognitive impairment without cerebellar signs. Analysis of other types of SCAs was all negative.

CONCLUSIONS

This is the first study of SCA8, SCA10, SCA12, SCA17 and SCA19 in Thais. SCA17 appears to be an important cause of ataxia in Thailand. Although, the pathological cut-off point of the TBP repeat allele remains unclear, the finding suggests that the 41-repeat may be a pathological allele resulting late-onset or mild phenotype. Apart from ataxia, cognitive impairment and parkinsonism may be clinical presentations in these carriers.

Strategies for treatment of dystonia

Treatment of dystonias is generally symptomatic. To produce sufficient therapy effects, therefore, frequently a multimodal and interdisciplinary therapeutic approach becomes necessary, combining botulinum toxin therapy, deep brain stimulation, oral antidystonic drugs, adjuvant drugs and rehabilitation therapy including physiotherapy, occupational therapy, re-training, speech therapy, psychotherapy and sociotherapy. This review presents the recommendations of the IAB-Interdisciplinary Working Group for Movement Disorders Special Task Force on Interdisciplinary Treatment of Dystonia. It reviews the different therapeutic modalities and outlines a strategy to adapt them to the dystonia localisation and severity of the individual patient. Hints to emerging and future therapies will be given.

Exploring the effect of electrical muscle stimulation as a novel treatment of intractable tremor in Parkinson's disease

BACKGROUND

As the pathophysiology of tremor in Parkinson disease (PD) involves a complex interaction between central and peripheral mechanisms, we propose that modulation of peripheral reflex mechanism by electrical muscle stimulation (EMS) may improve tremor temporarily.

OBJECTIVES

To determine the efficacy of EMS as a treatment for drug resistant tremor in PD patients.

METHODS

This study was a single-blinded, quasi-experimental study involving 34 PD patients with classic resting tremor as confirmed by tremor analysis. The EMS was given at 50Hz over the abductor pollicis brevis and interrosseus muscles for 10s with identified tremor parameters before and during stimulation as primary outcomes.

RESULTS

Compared to before stimulation, we observed a significant reduction in the root mean square (RMS) of the angular velocity (p<0.001) and peak magnitude (p<0.001) of resting tremor while tremor frequency (p=0.126) and dispersion (p=0.284) remained unchanged during stimulation. The UPDRS tremor score decreased from 10.59 (SD=1.74) before stimulation to 8.85 (SD=2.19) during stimulation (p<0.001). The average percentage of improvement of the peak magnitude and RMS angular velocity was 49.57% (SD=38.89) and 43.81% (SD=33.15) respectively. 70.6% and 61.8% of patients experienced at least 30% tremor attenuation as calculated from the peak magnitude and RMS angular velocity respectively.

CONCLUSIONS

Our study demonstrated the efficacy of EMS in temporarily improving resting tremor in medically intractable PD patients. Although tremor severity decreased, they were not completely eliminated and continued with a similar frequency, thus demonstrating the role of peripheral reflex mechanism in the modulation of tremor, but not as a generator. EMS should be further explored as a possible therapeutic intervention for tremor in PD.

What is the evidence to support home environmental adaptation in Parkinson's disease? A call for multidisciplinary interventions

"Home" is where one has a sense of belonging and feels secure, but it can also be a risky place for people with Parkinson's disease (PD). PD patients need assistance making adjustments to their physical environment to maintain appropriate care and provide a safe environment. This relationship is called the "person-environmental fit" (P-E fit). While most PD patients remain in their own homes, little is known about the specific challenges that PD patients and their caregivers encounter in the routine activities of daily living. The aim of our study was to identify the existing evidence on the issue of housing environmental adaptation in PD by performing a systematic review with a proposal of development strategies to integrate a multidisciplinary team into a home environmental research. MEDLINE, and life science journals were searched by querying appropriate key words, but revealed very few publications in this area. However, early evidence suggested that PD patients do not enjoy an adequate P-E fit in their own homes and face more functional limitations compared to matched controls. We concluded that we need to develop research-based evaluation strategies that can provide us with a theoretical and conceptual basis as well as tools for analysis of the P-E fit for PD patients and caregivers. We recommend that individual members of the multidisciplinary team including patients, caregivers, physicians, rehabilitation specialists, and social workers use a team approach to identify the key indicators and solutions for the development of PD-specific solutions for improving the P-E fit.

Visual deprivation elicits subclinical postural inflexibilities in early Parkinson's disease

BACKGROUND

Postural instability is often experienced in the late stages of PD and is a marker of disease progression. Little information is available on the role of visual inputs as an adaptive strategy to compensate for postural instability in PD. The purpose of this study was to determine visual dependency for postural control in early PD.

METHODS

Thirty early PD subjects without postural complaints and 30 matched controls were evaluated for subtle postural instability using static posturography under eyes opened and eyes closed conditions.

RESULTS

No significant differences between groups were observed under eyes opened condition. In eyes closed condition, there was significantly greater mean sway in the mediolateral direction (p=0.01), mean sway velocity (p=0.03), lateral sway velocity (p=0.04), and sway area (p=0.04) in PD than in the control subjects. 95% confidence ellipse of mean sway was largest in PD patients with eyes closed. A strong and significant correlation was observed between disease duration and mean mediolateral sway, sway area, mean sway and lateral sway velocity, and a moderate correlation was shown between Hoehn & Yahr stage and mean mediolateral sway, and sway area.

CONCLUSION

Our findings suggest that visual dependency exists in early PD and visual deprivation task can help identify subclinical postural instability.

Temporal fluctuation analysis of tremor signal in Parkinson's disease and Essential tremor subjects

Tremor is a common symptom shared in both Parkinson's disease (PD) and Essential tremor (ET) subjects. The differential diagnosis of PD and ET tremor is important since the treatment depends on specific medication. A novel feature was developed based on a hypothesis stating that the tremor of PD subject has a larger fluctuation while performing resting task than action task. Tremor signal was collected using a gyroscope sensor attached to subject's finger. The angular velocity signal was analyzed by transforming a one-dimensional to two-dimensional signal based on relation of different units of time-delay. The tremor fluctuation was defined as the area of 95% confidence ellipse covering the two-dimensional signal. Experimenting with 32 PD and 20 ET subjects, a ratio of fluctuation of resting to kinetic task can be a sensitive feature to discriminate PD from ET with 100% accuracy.

Nocturnal manifestations of atypical parkinsonian disorders

Although nocturnal disturbances are increasingly recognized as an integral part of the continuum of daytime manifestations of Parkinson's disease (PD), there is still little evidence in the medical literature to support the occurrence of these complex phenomena in patients with atypical parkinsonian disorders (APDs). Based on the anatomical substrates in APDs, which are considered to be more extensive outside the basal ganglia than in PD, we might expect that patients with APDs encounter the whole range of nocturnal disturbances, including motor, sleep disorders, autonomic dysfunctions, and neuropsychiatric manifestations at a similar, or even greater, frequency than in PD. This article is a review of the current literature on the problems at nighttime of patients with progressive supranuclear palsy, multiple system atrophy, corticobasal degeneration, and dementia with Lewy bodies. MEDLINE, life science journals and online books were searched by querying appropriate key words. Reports were included if the studies were related to nocturnal manifestations in APDs. Forty articles fulfilled the selection criteria. Differences between these symptoms in APDs and PD are highlighted, given the evidence available about each manifestation. This analysis of nocturnal manifestations of APDs suggests the need for future studies to address these issues to improve the quality of life not only of patients with APDs but the caregivers who encounter the challenges of supporting these patients on a daily basis.

Factors influencing secondary non-response to botulinum toxin type A injections in cervical dystonia

BACKGROUND

The development of secondary non-response (SNR) to botulinum neurotoxin type-A (BoNT-A) is considered a key issue in the management of cervical dystonia (CD). This case-controlled study was performed to systematically identify factors influencing SNR during BoNT-A therapy.

METHODS

This was a retrospective, international, non-interventional study of CD patients. Patients with SNR were matched with up to three responder patients (control) on the basis of duration of therapy and number of injection cycles. Factors influencing the development of SNR were screened using a univariate logistic regression model and confirmed using a multivariate conditional logistic regression model.

RESULTS

216 patients were enrolled, and 201 (SNR = 52; responder = 149) were matched and subdivided into blocks (doublets, triplets or quadruplets). At baseline, a significantly higher proportion of SNR patients had received previous or concomitant therapies (p = 0.038) and surgery for CD (p = 0.007) compared with controls. Although disease severity at onset was similar between groups, a significantly higher proportion of SNR patients experienced severe CD at the time of SNR compared with controls at the last documented visit. Multivariate analyses identified five factors that were significantly associated in predicting SNR (odds ratio [OR] > 1 indicated higher chances for being SNR): previous surgical procedure for CD (OR 9.8, p = 0.013), previous BoNT-A related severe adverse event (AE) (OR 5.6 p = 0.027), physical therapy (OR 4.6, p = 0.028), neuroleptic use (OR 3.3, p = 0.019) and average BoNT-A dose (OR 2.7, p = 0.010).

CONCLUSIONS

These findings suggest that SNR may not reflect true pharmacological resistance to BoNT-A therapy, but may be related to underlying disease severity.

Blepharoclonus: anatomical localization and etiological consideration

Blepharoclonus refers to myoclonic rhythmic eyelid closure. This is an extremely rare abnormal movement of the eyelids. The symptom has an ill-defned anatomical localization and hypothesized etiologies are diverse. We describe a 42 year-old woman with known poorly controlled hypertension (HTN) who presented with a three-week history ofataxia, dysmetria, and uncontrolled eyelid twitching. The bilateral abnormal eyelid movement occurred during either eyelid closure or opening, and was compatible with blepharoclonus. MRI revealed multiple cerebral infarctions at red nucleus, dentate nucleus, and inferior olives. These foci are within Guillain-Mollaret's triangle. The ataxia and dysmetria gradually improved within three weeks. While the blepharoclonus improved, it persisted after one year offollow-up. Our conclusion was one of HTN leading to a lacunar infarct that manifested partially as blepharoclonus. Due to the neuroimaging findings and clinical course, we propose that blepharoclonus may be a variant ofpalatal myoclonus and may be considered as another lacunar syndrome.

Transplacental transfer of NMDA receptor antibodies in an infant with cortical dysplasia

A confused and agitated 18-year-old woman presented to the emergency unit with orolingual movements, eye deviation, and a temperature of 38°C. The symptoms had begun 2 weeks prior to the admission when she developed a severe headache associated with pathologic laughing and intermittent episodes of upgaze deviation. A urine pregnancy test was positive and a transvaginal ultrasonography showed a 9-week-old fetus. An MRI of the brain was unremarkable and results of the CSF analysis were also unremarkable apart from a CSF pleocytosis (62 lymphocytes) and slightly elevated protein (55 mg/dL; normal range 0-45 mg/dL). Extensive microbiologic and serologic studies with CSF were all negative. She gradually lost consciousness, experienced respiratory failure, and was intubated. There were semirhythmic movements consisting of complex patterns of mouth opening, chewing, facial grimacing, synchronous flexion-extension, and supination-pronation limb movements, which persisted during the period of unresponsiveness. She also had generalized hyperreflexia, persistent hyperthermia, and a full bladder. Three EEGs showed diffuse slow waves with no epileptic discharges. A diagnosis of anti-NMDA receptor (NMDAR) encephalitis was made on clinical grounds and strongly positive serum NMDAR antibodies.