Postural stability in blepharospasm: the effects of dual-tasking and botulinum toxin therapy

Background

Blepharospasm is a focal dystonia that presents as involuntary, intermittent, continuous contractions of the eyelids. Abnormal eyelid contractions in blepharospasm are expected to cause balance problems, but there is no clear information.

Objective

This study was designed to evaluate the effect of blepharospasm on postural stability (PS) in patients with blepharospasm. As a secondary endpoint, the efficacy of botulinum toxin type-A (BoNT-A) treatment on static balance in patients with blepharospasm was investigated.

Methods

Twenty-four patients with blepharospasm receiving regular BoNT-A injections and 20 age-matched and sex-matched healthy controls were included in the study. All subjects were evaluated on a static posturography force platform performing four tasks (eyes open (EO), eyes closed (EC), tandem Romberg (TR) and verbal cognitive task (COGT)). Evaluations of the patients were repeated 4 weeks after the injection.

Results

Pretreatment lateral and anterior-posterior sways, sway area and velocities of the sways were significantly higher in patients than controls during the COGT and TR (p<0.05). In the patient group, with EO and EC, a few parameters improved after BoNT-A injection. On the other hand, in the TR and COGT, most of the sway parameters and velocities improved significantly after treatment (p<0.05).

Conclusions

Blepharospasm may cause functional blindness in patients. This study demonstrated that PS worsens in patients with blepharospasm under dual-task conditions. BoNT-A injection treats the disease itself and, thus, markedly improves PS under dual-task conditions in blepharospasm.

Coexistence of restless legs syndrome and multiple sclerosis aggravates anxiety and depression

BACKGROUND

Among the comorbidities that accompany multiple sclerosis (MS), restless legs syndrome (RLS) is one of the most common. Anxiety and depression are common psychological comorbidities that impact the quality of life of patients with MS (PwMS), as well as patients with RLS.

OBJECTIVE

To investigate the psychiatric burden of MS and RLS coexistence, we conducted a nationwide, multicenter and cross-sectional survey.

METHODS

Participants were assessed by using demographic and clinical parameters along with the Hamilton Anxiety and Hamilton Depression Scales (HAM-A and HAM-D).

RESULTS

Out of the 1,068 participants, 173 (16.2%) were found to have RLS [RLS(+)] and 895 (83.8%) did not [RLS(-)]. The mean scores for HAM-A and HAM-D were significantly higher among RLS(+) subjects than among RLS(-) subjects (p<0.001 for all variables).

CONCLUSIONS

According to our data, the presence of RLS in PwMS may increase the occurrence of both anxiety and depression symptoms. Awareness and treatment of RLS in PwMS could possibly reduce the symptoms of psychiatric comorbidities originating from RLS.

The Turkish experience of COVID-19 infection in people with NMOSD and MOGAD: A milder course?

Background

COVID-19 is a multisystemic infection with variables consequences depending on individual and comorbid conditions. The course and outcomes of COVID-19 during neuromyelitis optica spectrum disorders (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disorders (MOGAD) are not clearly known.

Objective/methods

The aim of this study was to examine the features and outcomes of COVID-19 infection in NMOSD and MOGAD patients. The patients' demographic and clinical factors, disease modifying treatment (DMT) used and disease information of COVID-19 infection were recorded. Conditions leading to hospitalization and severe exposure to COVID-19 infection were also analyzed.

Results

The study included 63 patients from 25 centers. Thirty-two patients (50.8%) belong to AQP-4 seropositive group, 13 (20.6%) and 18 (28.6%) were in MOG-positive and double-seronegative groups, respectively. Risk factors for severe COVID-19 infection and hospitalization were advanced age, high disability level and the presence of comorbid disease. Disease severity was found to be high in double-seronegative NMOSD and low in MOGAD patients. No statistically significant effect of DMTs on disease severity and hospitalization was found.

Conclusion

In NMOSD and MOGAD patients, advanced age, high disability and presence of comorbid disease pose risks for severe COVID-19 infection. There was no direct significant effect of DMTs for COVID-19 infection.

Contribution of functional dopamine D2 and D3 receptor variants to motor and non-motor symptoms of early onset Parkinson's disease

In the present study, we focused on investigating the contribution of functional dopamine D2 and D3 receptor variants to motor and/or non-motor symptoms of early onset Parkinson's disease (EOPD). Three functional single nucleotide polymorphisms (SNPs), DRD3 rs6280, DRD2 rs2283265 and DRD2 rs1076560, were genotyped in 128 Turkish EOPD patients and then, statistical analysis was conducted for the potential impacts of SNPs on clinical parameters. All three SNPs were found to be statistically significant in terms of PD-related pain: DRD3 [rs6280; risk allele "T" for pain; p = 0.031; odds ratio (OR)=4.25], DRD2 [rs2283265; risk allele "A" for pain; p = 0.001; OR=8.47] and, DRD2 [rs1076560; risk allele "A" for pain; p = 0.022; OR=4.58]. Additionally, bilateral disease [p = 0.011; OR=5.10] and gender [risk group "female"; p = 0.003; OR=8.53] were also identified as significant univariate risk factors for PD-related pain. Based on logistic regression analysis conducted with the significant univariate risk factors, this the first report to clarify that a female patient with bilateral PD and DRD2 rs2283265 polymorphism has a significant risk for PD-related pain. Our findings might contribute to improve life quality by offering treatment options for pain in PD patients with these clinical and genetic features.

Evaluation of postural balance in patients with obstructive sleep apnoea syndrome

INTRODUCTION

Patients with obstructive sleep apnoea syndrome (OSAS) can be more prone to accidents due to excessive daytime sleepiness which can lead to attention deficits and thereby cause balance problems. One of the tests evaluating postural balance is static posturography (SPG). In this study, we aimed to evaluate postural balance with SPG in OSAS patients.

METHODS

Patients who were referred to a sleep disorders outpatient clinic of a tertiary health care centre with snoring, daytime sleepiness or witnessed apnoea were enrolled consecutively in this cross-sectional study. They were grouped as the OSAS group and the control group according to the apnoea-hypopnoea index. Posturographic analyses were carried out in all subjects on a SPG platform under five different conditions: eyes open (EO), eyes closed (EC), head rotated to left (HL), head rotated to right (HR), and tandem Romberg.

RESULTS

A total of 95 patients and 23 controls were included in the study. In EO conditions, there was no difference between the OSAS group and the control group in any of the posturographic parameters. In EC conditions, change in lateral sway was significantly higher in the OSAS group which also correlated negatively with SaO2(min). HR conditions caused an i ncrease in anterior-posterior (A-P) sway velocity, and HL conditions led to an increase in change in lateral and A-P sways, sway area, and sway area velocity in the OSAS group.

CONCLUSIONS

Our findings suggest that postural balance in OSAS patients is impaired even in the very first hours of the day, and that the severity of the disease has an impact on postural balance.

Epigenetic approach to early-onset Parkinson's disease: low methylation status of SNCA and PARK2 promoter regions

Background and aim The effect of epigenetic modifications in the genes related to Parkinson's disease (PD) is still unclear. In the present study, we investigated methylation status of SNCA and PARK2 genes in patients with early-onset Parkinson's disease (EOPD). Materials and methods The promoter region methylation status of SNCA and PARK2 genes was evaluated by methylation specific-PCR (MSP) in 91 patients with EOPD and 52 healthy individuals. Results The methylation of SNCA and PARK2 promoter regions were significantly lower in EOPD patients compared to the control group (P = 0.013 and P = 0.03, respectively). We also found that the methylation status of the SNCA might be associated with positive family history of PD (P = 0.042). Conclusion Although it should be supported by further analysis, based on the results of the present study, the methylation status of SNCA and PARK2 genes might contribute to EOPD pathogenesis.

Crossed aphasia in multiple sclerosis

Aphasia is a rare sign of multiple sclerosis (MS). Several different forms of aphasia have been reported in MS. We report, to our knowledge, the first case of a MS patient with crossed aphasia during an attack.

Multiple sclerosis patients with and without sexual dysfunction: are there any differences?

Objective Sexual dysfunction (SD) severely affects the quality of life in patients with multiple sclerosis (MS). The aim of this study is to investigate the type and frequency of sexual complaints in MS patients, to analyse their relationship to various clinical and psychosocial variables and to clarify the differences between MS patients with and without SD.

Methods Thirty-five relapsing-remitting (RR), nine secondary progressive and seven primary progressive MS patients were included in this study. A structured face-to-face interview regarding sexual function and other physical problems which may interfere with sexual functioning was administered to each patient. They also filled out Multiple Sclerosis Intimacy and Sexuality Questionnaire-19 (MSISQ-19), which includes items for primary (direct physical), secondary (indirect physical) and tertiary (psychosocial) causes of SD. Disability, cognitive functions and psychological functioning were also evaluated.

Results Forty-one patients (80.4%) reported primary SD; decreased libido was the most frequent complaint (80.5%). These patients were older and more disabled, however 39% had low disability scores. SD was a common problem for both men and women. Patients with RRMS were affected less in all items of primary SD. Several items of secondary SD-problems with memory and concentration, bladder symptoms, bowel symptoms-showed correlation with different items of primary SD; these were altered genital sensation, decreased libido, increased time for arousal, decreased lubrication/difficulties with erection. Total MSISQ-19 scores were correlated with disease duration, age, disability, disease course, Beck depression scale, temporary and long-standing anxiety and low level of education.

Conclusion SD is an underestimated, common symptom of MS. It may occur in MS even in the absence of severe disability. Physicians’ awareness of this problem may help to bring about appropriate treatments and management, and improve the quality of life for these patients.

Evaluation of the Innermost Retinal Layers and Visual Evoked Potentials in Patients with Multiple Sclerosis

PURPOSE

The present study was conducted to investigate alterations in the innermost layers of the retina using optical coherence tomography (OCT) and to assess potential associations of structural measures with functional markers in patients with Multiple Sclerosis (MS).

MATERIALS AND METHODS

Ninety-four eyes of 47 MS patients and 60 eyes of 30 healthy individuals were included in the study. All patients underwent complete ophthalmological examination and OCT imaging to analyze peripapillary retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL) thickness. Visual evoked potentials (VEPs) and expanded disability status scale (EDSS) score were assessed for MS patients.

RESULTS

The average RNFL and GCIPL thicknesses were thinner in MS patients (86.2 ± 11.9 µm and 73.6 ± 9.7 µm, respectively) when compared with those of healthy controls (96.7 ± 8.2 µm and 85.9 ± 4.6 µm, respectively, p < 0.001 for both). Within MS patients, the average RNFL and GCIPL thicknesses were lower in eyes with a prior history of optic neuritis (MS ON) than in eyes with no optic neuritis history (MS non-ON) (p = 0.012 and p < 0.001, respectively). RNFL and GCIPL thicknesses were inversely correlated with VEP latency (r = -0.40, p < 0.001 and r = -0.36, p < 0.001, respectively) in MS patient eyes. There was a correlation between GCIPL thickness and VEP amplitude in eyes with previous ON history (r = 0.34, p = 0.035). No significant correlations were found between OCT measurements and EDSS score.

CONCLUSIONS

Innermost layers of the retina are highly affected by the pathophysiologic process in MS disease, manifesting as a reduction in RNFL and GCIPL thickness. The structural retinal changes show correlation with alterations in potentials showing the optic pathway function.

Evaluation of Choroidal Vascular Changes in Patients with Multiple Sclerosis Using Enhanced Depth Imaging Optical Coherence Tomography

OBJECTIVE

To evaluate the choroidal thickness in patients with multiple sclerosis (MS) using enhanced depth imaging optical coherence tomography (EDI-OCT).

METHODS

In this observational comparative study, 68 eyes of 34 MS patients and 60 eyes of 30 healthy subjects were evaluated. All participants underwent complete ophthalmologic examination and OCT scanning. Choroidal thickness measurements were performed at seven points.

RESULTS

The mean subfoveal choroidal thickness was reduced significantly in MS patients (310.71 ± 61.85 μm) versus healthy controls (364.85 ± 41.81 μm) (p < 0.001). The difference was also significant at all six measurement points (p < 0.001 for all). Choroidal thickness measurements revealed no significant difference between MS eyes with a prior optic neuritis (ON) history (MS ON) and those without ON history (MS non-ON). Subfoveal choroidal thickness did not correlate with retinal nerve fiber layer and Expanded Disability Status Scale score, but reduced choroidal thickness was associated with longer disease duration (r = -0.28, p = 0.019) in MS patients.

CONCLUSION

In MS patients, choroidal structural changes occur both in MS ON and MS non-ON eyes. The decreased choroidal thickness might provide evidence to support a potential role of vascular dysregulation in the pathophysiology of MS.

Prevalence and risk factors of low bone mineral density in patients with multiple sclerosis

OBJECTIVES

To determine the prevalence and risk factors of low bone mineral density (BMD) in patients with multiple sclerosis (MS).

METHODS

Patients with MS who had undergone a BMD evaluation via dual-energy X-ray absorptiometry (DXA) between January 2010 and December 2013 were included in the study. Descriptive data, BMD values, and risk factors for osteoporosis along with the details regarding MS, such as age at onset, duration of disease, clinical type of MS, expanded disability status scale (EDSS) scores, and lifetime steroid intake were obtained from the medical record database and telephone interview.

RESULTS

The study group comprised 67 patients with a mean age of 41.1 ± 10.2 years. Of the patients, 20.9% revealed low BMD for chronological age. Vitamin D insufficiency (25(OH)D < 20  ng/ml) rate was 86.6%. Comorbidity and EDSS scores of patients with low BMD were significantly higher than those of the remaining patients (P = 0.000 and P = 0.015, respectively). Neck BMD was inversely correlated with comorbidity score, disease duration, relapse number, and lifetime steroid intake (r = - 0.270, r = - 0.263, r = - 0.359, and r = - 0.314, respectively).

CONCLUSION

The current study revealed that low BMD and vitamin D insufficiency were common in patients with MS. Longer disease duration, higher comorbidity score, and severe disability level led to lower BMD values. In conclusion, it is of paramount importance for clinicians to pay more attention on bone health in MS and to tailor preventative measures meticulously.

Motor neuron disease associated with multiple myeloma

The association between Amyotrophic Lateral Sclerosis or other Motor Neuron Diseases (MNDs) with Lymphoproliferative Disorders (LPDs) and plasma cell neoplasias (such as Hodgkin's or non-Hodgkin's lymphoma, Waldenstrom's macroglobulinemia, multiple myeloma, chronic lymphocytic leukemia) has been described. It is not clear whether LPDs play a role in the pathogenesis of MND; however it is possible that patients might have antibodies against motor neurons. An association between motor neuron disease and Multiple myeloma (MM) is rarely reported in the literature. This article reports a case of a 75-year-old male with MM and MND. Interestingly, the patient was in complete remission for MM when he was diagnosed as MND and he died due to progressive MND.

Global aphasia due to left thalamic hemorrhage

Global aphasia is an acquired language disorder characterized by severe impairments in all modalities of language. The specific sites of injury commonly include Wernike's and Broca's areas and result from large strokes--particularly those involving the internal carotid or middle cerebral arteries. Rarely, deep subcortical lesions may cause global aphasia. We present three cases with global aphasia due to a more rare cause: left thalamic hemorrhage. Their common feature was the large size of the hemorrhage and its extension to the third ventricule. HMPAO-SPECT in one of the cases revealed ipsilateral subcortical, frontotemporal cortical and right frontal cortical hypoperfusion. Left thalamic hemorrhage should be considered in the differential diagnosis of global aphasia.

Transient parkinsonism: Induced by progesterone or pregnancy?

We report on the development of transient parkinsonism after progesterone injection in a pregnant patient with a risk of abortion. Etiological possibilities are discussed, including pregnancy itself, possible toxic effects of the dead fetus, and progesterone injection. Progesterone-induced parkinsonism seems the most likely diagnosis in this case.

A whole genome screen for linkage in Turkish multiple sclerosis

Factors exerting recessive effects on susceptibility to complex traits are expected to be over-represented in communities having a higher frequency of consanguineous marriage. Multiple sclerosis, a typical complex trait, is relatively common in Turkey where cultural factors also determine a high rate of consanguineous marriage. Previous genetic studies of multiple sclerosis in Turkey have been confined to the search for associations with candidate genes. In order to exploit the special genetic features of the Turkish population, we performed a whole genome screen for linkage in 43 Turkish multiplex families employing 392 microsatellite markers. Two genomic regions where maximum lod score (MLS) values were suggestive of linkage were identified (chromosomes 13q and 18q23) along with a further 14 regions of potential linkage. Parametric analysis of these data using a recessive model, appropriate for populations with a high frequency of consanguinity, increased the LOD scores in four regions.

The effects of cold stress test on vasomotor tonus in normal controls

Plethsymographic recordings are used to evaluate changes in peripheral vascular tonus. Twenty-six volunteers (15 men, 11 women) with a mean age 31 years were included in this study. Plethsymographic recordings were done both at baseline and +40C temperatures bilaterally. Significant reductions in systemic blood flow were noted with different maneuvers. Reactive hyperemia occurring after ischemia was local, however local reduction in blood flow after cold test was systemic. As the local temperature increased, the blood flow parameters normalized, too. In normal controls these values normalized in 20 minutes. The changes in vasomotor tonus due to cold test demostrated a parallel pattern.

Vascular parkinsonism: a distinct, heterogeneous clinical entity

OBJECTIVES

The aim of this study was to define the symptoms and signs of suspected vascular parkinsonism (VP) which is still a debatable concept.

MATERIAL AND METHODS

Patients with parkinsonism were grouped into patients with suspected VP and Parkinson's disease (PD) after other causes for secondary parkinsonism, and parkinsonism-plus syndromes were excluded. The clinical features of 16 patients with suspected VP to those of 50 diagnosed with PD were compared. All patients were assessed using unified Parkinson's disease rating scale (UPDRS) and all had cerebral MRIs.

RESULTS

Patients with VP had significantly older onset age and shorter duration of disease with gait disorder as the most frequent initial symptom. All PD patients had satisfactory response to levodopa treatment, whereas only 38% VP patients had satisfactory response to levodopa treatment. Vascular risk factors were more common in VP (81%) than PD (32%). Postural instability, freezing, gait disturbance, pyramidal signs, and postural tremor were significantly more prevalent in patients with VP than in PD. In VP patients these features were more prominent in the lower limbs. Twenty-five percent had acute onset VP. All patients with VP had ischemic lesions, mainly in subcortical white matter, to a lesser extent basal ganglia and brainstem, in their cerebral MRIs, while 70% of PD patients had normal MRIs.

CONCLUSION

The differences in the clinical features support the concept that VP is a distinct clinical entity with heterogeneous clinical, MRI, and possibly pathophysiological features.

Wegener's granulomatosis : a case with multiple symmetric cranial neuropathy

We report a 47 year-old woman with Wegener's granulomatosis presenting with an atypical onset of multiple symmetric cranial neuropathies. The diagnosis was established by clinical and laboratory data. To our knowledge, this is the first case of Wegener's granulomatosis presenting with bilateral multiple symmetric cranial neuropathy.

Survival and predictors of disability in Turkish MS patients. Turkish Multiple Sclerosis Study Group (TUMSSG)

OBJECTIVE

To examine the natural history, survival, and prognostic factors in a sample of Turkish MS patients.

METHOD

This multicenter study included 1,259 definite MS patients diagnosed according to the criteria of Poser et al. Actuarial analysis of selected disability levels of 3, 6, 8, and 10 achieved with the Expanded Disability Status Scale (EDSS); a multivariate Cox regression analysis for prognostic factors related to time to reach EDSS > or = 6; and Pearson's correlation coefficient for individual factors were performed.

RESULTS

The survival (+/- SE) at 15 years from onset was 94.6 +/- 2.9%, and at 25 years was 89.0 +/- 5.8%. The disability reached by 15 years was EDSS > or = 3 in 66.4%, EDSS > or = 6 in 41.2%, EDSS > or = 8 in 10.5%, and EDSS = 10 in 5.4%. The most significant unfavorable prognostic factors were progressive course (relative risk [RR], 3.73; CI, 2.71 to 5.13) and sphincter symptoms at onset (RR, 1.86; CI, 1.23 to 2.82), followed by male sex, motor symptoms at onset, and a high attack frequency within the first 5 years. Primary progressive disease was correlated positively with male sex (r = 0.0895, p = 0.001), older age (r = 0.1807, p = 0.000), and motor (r = 0.1433, p = 0.000) or sphincter symptoms (r = 0.1001, p = 0.000) at onset, unlike relapsing-remitting and secondary progressive disease.

CONCLUSIONS

Although a slightly better prognosis is observed in the Turkish MS population, early prognostic factors are similar to most of the previous Western series. Primary progressive disease, mostly seen in older men with motor and sphincter involvement at onset, has a worse prognosis and may represent a distinct behavioral variant of MS.

Transesophageal echocardiography in various ischemic stroke subtypes

Transesophageal echocardiography (TEE) is more sensitive than transthoracic echocardiography (TTE) in detecting the potential source of emboli in cardioembolic strokes (CES). To establish the prevalence of a potential cardiac source of embolism detectable on TEE and its relationship to vascular risk factors, an unselected ischemic stroke population was evaluated. Twenty-six age and sex-matched cases with normal cardiological and neurological examinations as well as normal CT-scans, TTE and ECGs were included in the study as the control group. One hundred and eight patients with cardioembolic stroke (53 patients), atherothrombotic stroke (36 patients), and lacunar stroke (19 patients) were investigated by TTE and TEE. Seven of the 26 (26.9%) controls had thoracic atherosclerotic plaques on TEE examinations. The prevalence of abnormal TEE findings in patients was higher compared to the controls (p < 0.001). TEE revealed more specific findings in every etiological group when compared to TTE (74.0% vs 10.2%, p < 0.001). Atrial fibrillation correlated with the abnormalities of TEE (p < 0.05) while other risk factors did not. Left atrial spontaneous echo contrast was the most common finding on TEE of cases with cardioembolic stroke while atherosclerotic aortic plaques were mostly encountered in patients with atherothrombotic stroke. No specific findings by TEE were seen in patients with lacunar stroke. TEE is capable of detecting definite etiologies in cardioembolic stroke and associated cardiac pathologies in atherothrombotic stroke and lacunar stroke. These observations suggest that TEE is a useful tool to guide the physician for the treatment of ischemic stroke patients.

Neurologic presentation of Wilson disease without Kayser-Fleischer rings

A 41-year-old woman presented with a 6-month history of gradually progressive postural instability and dysarthria associated with cerebellar and extrapyramidal signs. No Kayser-Fleischer (K-F) rings were observed on biomicroscopic examination of each cornea. The only evidence of hepatic dysfunction was a modest elevation of alanine-aminotransferase. The diagnosis of Wilson disease (WD) was based on low serum ceruloplasmin, abnormal serum copper and urinary copper excretion, and DNA marker segregation analysis. WD should be considered in the presence of characteristic neurologic and laboratory features, regardless of age at onset, evidence of hepatic dysfunction, or absence of K-F rings.

Ecstasy intoxication: an overlap between serotonin syndrome and neuroleptic malignant syndrome

3,4-Methylenedioxymethamphetamine (MDMA), also known as "ecstasy" is a popular recreational drug with potential for abuse. Although its neurotoxic effects have been established in animal studies, the acute and long-term effects of this serotonergic agent in humans are still unknown. We describe a 19-year-old woman with overlapping symptoms of neuroleptic malignant syndrome and serotonin syndrome after a single exposure to MDMA. We also review 15 other cases reported in the literature to draw attention to the serious neurotoxicity, including fatal outcomes, caused by the use of this increasingly popular, illicit drug.

Bromocriptine is ineffective in the treatment of chronic nonfluent aphasia

The effect of bromocriptine on chronic nonfluent aphasia was investigated in 4 patients suffering from a stroke 24 to 35 months before the onset of this study (average 29 months). Two patients had Broca, one had global and the other transcortical motor aphasia. CT-scans demonstrated anterior-posterior infarctions in 3 patients and anterior infarction in one. Bromocriptine was given initially at a dosage of 10 mg/day, and of 25 mg/day during the follow ups. By means of aphasia tests, bromocriptine was found to be ineffective for the treatment of any symptoms of chronic nonfluent aphasia.

Paroxysmal dyskinesias: clinical features and classification

We studied 46 patients with paroxysmal dyskinesia and classified them according to phenomenology, duration of attacks, and etiology. There were 13 patients, 7 females, who had paroxysmal kinesigenic dyskinesia (PKD), 10 with attacks lasting 5 minutes or less (short lasting) and 3 with attacks lasting longer than 5 minutes (long lasting). Twenty-six patients, 18 females, had paroxysmal nonkinesigenic dyskinesia (PNKD), 9 with short-lasting and 17 with long-lasting PNKD. Five patients, 3 females, had paroxysmal exertion-induced dyskinesia (PED), 3 with short-lasting PED and the other 2 with long-lasting PED. In addition, there was 1 patient with paroxysmal hypnogenic dyskinesia (PHD) and 1 with paroxysmal superior oblique myokymia. Only 2 patients, 1 with PKD and 1 with PHD, had family history of paroxysmal dyskinesias. No specific cause could be identified in 21 patients; in the other 23 patients the etiologies included the following: psychogenic (9 patients), cerebrovascular diseases (4), multiple sclerosis (2), encephalitis (2), cerebral trauma (2), peripheral trauma (2), migraine (1), and kernicterus (1). Nine of 10 (90%) patients with PKD improved with medications, mostly anticonvulsants, compared with only 7 of 19 (37%) with PNKD. This new classification, based chiefly on precipitating events, allowed appropriate categorization of the attacks in all our patients with paroxysmal dyskinesias.