Su Jin Chung

Diagnostic value of brain MRI and 18F-FDG PET in the differentiation of Parkinsonian-type multiple system atrophy from Parkinson's disease.

Background and purpose:  Differentiation between parkinsonian type multiple system atrophy (MSA‐P) and Parkinson’s disease (PD) is important but often difficult. We investigated the diagnostic value of brain magnetic resonance imaging (MRI) and 18F‐fluorodeoxyglucose positron emission tomography (18F‐FDG PET) in differentiating MSA‐P from PD.

Apathy and striatal dopamine defects in non-demented patients with Parkinson's disease

INTRODUCTION Apathy is a common, disabling symptom in Parkinsons disease (PD). The mechanisms underlying apathy in PD are still unclear, although they may be related to dysfunction in the meso-cortico-limbic circuit, including the ventral striatum. Thus, we performed this study to investigate whether dopamine depletion in the ventral striatum contributes to apathy in PD. METHODS We conducted a survey of the degree of apathy (using the Korean version of the Apathy Evaluation Scale, AES-S) in 108 non-demented patients with PD who underwent dopamine transporter (DAT) positron emission tomography scans as an initial diagnostic work-up. Patients with AES-S scores of 37 or higher were defined as having apathetic PD. The Beck Depression Inventory (BDI) was administered to assess the severity of depression. Patients with BDI scores of 15 or higher were regarded as having depression. RESULTS Apathetic patients (n = 34) tended to exhibit higher BDI scores than non-apathetic patients (n = 74); however, other clinical variables were comparable between the two groups. DAT activity in the striatal sub-regions was also similar between the two groups. Selecting only non-depressed patients, including 20 apathetic and 47 non-apathetic patients, did not alter the results. CONCLUSIONS This study demonstrated that the pattern of striatal dopamine depletion does not contribute to the degree of apathy in early PD. Apathy in PD may be associated with extra-striatal lesions that accompany PD rather than striatal dopaminergic deficits.

Cerebral Microbleeds in Patients with Dementia with Lewy Bodies and Parkinson Disease Dementia

BACKGROUND AND PURPOSE: The burden of amyloid β is greater in patients with dementia with Lewy bodies than in those with Parkinson disease dementia, and an increased amyloid β load is closely related to a higher incidence of cerebral microbleeds. Here, we investigated the prevalence and topography of cerebral microbleeds in patients with dementia with Lewy bodies and those with Parkinson disease dementia to examine whether cerebral microbleeds are more prevalent in patients with dementia with Lewy bodies than in those with Parkinson disease dementia. MATERIALS AND METHODS: The study population consisted of 42 patients with dementia with Lewy bodies, 88 patients with Parkinson disease dementia, and 35 controls who underwent brain MR imaging with gradient recalled-echo. Cerebral microbleeds were classified as deep, lobar, or infratentorial. RESULTS: The frequency of cerebral microbleeds was significantly greater in patients with dementia with Lewy bodies (45.2%) than in those with Parkinson disease dementia (26.1%) or in healthy controls (17.1%; P = .017). Lobar cerebral microbleeds were observed more frequently in the dementia with Lewy bodies group (40.5%) than in the Parkinson disease dementia (17%; P = .004) or healthy control (8.6%; P = .001) group, whereas the frequencies of deep and infratentorial cerebral microbleeds did not differ among the 3 groups. Logistic regression analyses revealed that, compared with the healthy control group, the dementia with Lewy bodies group was significantly associated with the presence of lobar cerebral microbleeds after adjusting for age, sex, nonlobar cerebral microbleeds, white matter hyperintensities, and other vascular risk factors (odds ratio, 4.39 [95% CI, 1.27–15.25]). However, compared with the healthy control group, the Parkinson disease dementia group was not significantly associated with lobar cerebral microbleeds. CONCLUSIONS: This study showed that patients with dementia with Lewy bodies had a greater burden of cerebral microbleeds and exhibited a lobar predominance of cerebral microbleeds than did patients with Parkinson disease dementia.

Subcortical shape analysis of progressive mild cognitive impairment in Parkinson's disease

Cortical neural correlates of ongoing cognitive decline in Parkinsons disease (PD) have been suggested; however, the role of subcortical structures in longitudinal change of cognitive dysfunction in PD has not been fully investigated. Here, we used automatic analysis to explore subcortical brain structures in patients with PD with mild cognitive impairment that converts into PD with dementia.

Development of epilepsy after posterior reversible encephalopathy syndrome

PURPOSE This study was intended to describe the risk of epilepsy subsequent to posterior reversible encephalopathy syndrome (PRES) and the clinical features of post-PRES epilepsy. METHOD We retrospectively identified all patients with PRES who were admitted to Severance Hospital and consulted with the Department of Neurology between 2001 and 2013 and the subgroup of these patients who subsequently developed epilepsy. We also describe clinical features of patients who were not treated with PRES as inpatients at our center but who presented later with post-PRES epilepsy during the study period. We studied clinical characteristics during the acute symptomatic phase of PRES and after the development of epilepsy. RESULTS During the study period 102 patients were treated at our center during the acute phase of PRES. Four of these patients (3.9%) subsequently developed epilepsy. Two additional patients with a history of PRES presented to our hospital after the acute phase of their illness with post-PRES epilepsy. During the acute phase, five of six patients had acute symptomatic seizures and four had convulsive or nonconvulsive status epilepticus (SE). Acute phase MRI showed cytotoxic edema in five patients, and follow-up MRI showed focal atrophic changes including hippocampal sclerosis in four. Presumptive epileptogenic foci were located in the left-side temporal, parietal and occipital lobes, corresponding to the regions that showed cytotoxic edema or severe vasogenic edema as well as with the location or lateralization of EEG abnormalities during the acute phase. CONCLUSION Our findings indicate a small but not insignificant risk for the development of epilepsy after PRES. The presence of cytotoxic edema and severe, acute symptomatic seizures, such as SE suggests irreversible brain damage and may predict the development of epilepsy.

Striatal Dopamine Depletion Patterns and Early Non-Motor Burden in Parkinsons Disease

Background The mechanism underlying non-motor symptoms in Parkinson’s disease has not yet been elucidated. In this study, we hypothesized that Parkinson patients with more non-motor symptoms have a different pattern of striatal dopamine depletion, particularly in areas other than the sensorimotor striatum, compared to those with fewer non-motor symptoms. Methods We conducted a prospective survey of the degree of non-motor symptoms (using the Korean version of the Non-Motor Symptoms Scale; K-NMSS) in 151 patients with early-stage Parkinson’s disease who had undergone a dopamine transporter PET scan as an initial diagnostic procedure. We classified the patients into two groups; high non-motor patients (HNM-PD; K-NMSS score ≥ 41) and low non-motor patients (LNM-PD). Results Patients in the HNM-PD group (n = 71) were older, had longer symptom duration, exhibited more severe motor deficits, and had been prescribed higher levodopa-equivalent doses at follow-up than those in the LNM-PD group. However, dopamine transporter binding to the striatal sub-regions and inter-sub-regional binding ratios were comparable between the two groups. A general linear model showed that the HNM-PD group had significantly more severe motor deficits than the LNM-PD group after controlling for age, gender, symptom duration, and dopamine transporter binding to the sensorimotor striatum. Conclusions This study demonstrated that the pattern of striatal dopamine depletion does not contribute to early non-motor burden in Parkinson’s disease. Our results suggest that LNM-PD patients may have a more benign course of motor symptom progression than HNM-PD patients.

Familiar Hyperekplexia, a Potential Cause of Cautious Gait: A New Korean Case anda Systematic Review of Phenotypes

Familial hyperekplexia, also called startle disease, is a rare neurological disorder characterized by excessive startle responses to noise or touch. It can be associated with serious injury from frequent falls, apnea spells, and aspiration pneumonia. Familial hyperekplexia has a heterogeneous genetic background with several identified causative genes; it demonstrates both dominant and recessive inheritance in the α1 subunit of the glycine receptor (GLRA1), the β subunit of the glycine receptor and the presynaptic sodium and chloride-dependent glycine transporter 2 genes. Clonazepam is an effective medical treatment for hyperekplexia. Here, we report genetically confirmed familial hyperekplexia patients presenting early adult cautious gait. Additionally, we review clinical features, mode of inheritance, ethnicity and the types and locations of mutations of previously reported hyperekplexia cases with a GLRA1 gene mutation.

Does Smoking Impact Dopamine Neuronal Loss in de novo Parkinson's Disease?

This study analyzed data from dopamine transporter (DAT) positron emission tomographic scans of 282 male patients with de novo Parkinson disease to investigate whether smoking impacts striatal dopamine neuronal degeneration. Mean DAT activity in the posterior (p = 0.016) and ventral putamen (p = 0.028) was higher in 44 current smokers in comparison to 105 ex‐smokers and 133 never‐smokers. The severity of baseline motor deficits and the longitudinal increases in levodopa‐equivalent doses during follow‐up were similar among the 3 groups. These results suggest that current smoking, but not past smoking, protects dopamine neuronal degeneration in the sensorimotor striatum with no additional clinical benefits. Ann Neurol 2017;82:850–854

Effects of dopaminergic depletion and brain atrophy on neuropsychiatric symptoms in de novo Parkinson’s disease

Background Neuropsychiatric symptoms impact the patients’ quality of life and caregivers’ burdens in Parkinson’s disease (PD). We aimed to investigate the effects of striatal dopaminergic depletion and brain atrophy on the neuropsychiatric symptoms of patients with PD. Methods Two hundred and seven patients with de novo drug-naïve PD underwent dopamine transporter (DAT) positron emission tomography and brain MRI scanning. In addition, the patients were assessed with caregiver-administered neuropsychiatric inventory (NPI) questionnaires. To evaluate the effects of DAT uptake, subcortical volume and cortical thinning on the patients’ neuropsychiatric symptoms, we performed logistic regression and negative binomial regression analyses on the NPI data after controlling for possible confounders. Results Frontal cortical thinning was associated with the presence of nighttime behaviour and irritability, and the thinning correlated with the severity of the nighttime behaviour. Temporal cortical thinning was associated with the presence of aggression/agitation, and it correlated with the severity of the aggression/agitation. Subcortical atrophy in the accumbens was associated with the presence of disinhibition and correlated with the severity of the disinhibition. Putamen atrophy and insular thinning were independently associated with the presence of apathy, but only insular thinning correlated with the severity of the apathy. Of the predictors, only frontal cortical thinning correlated with the total NPI score. Conclusions The results of this study suggested that accumbens atrophy and frontotemporal cortical thinning, especially frontal cortical thinning, independently contributed to neuropsychiatric symptoms in patients with PD, while DAT uptake did not affect the neuropsychiatric symptoms.

Dental implants-induced task-specific oromandibular dystonia

Task-specificity is a unique characteristic of focal dystonia; that is, abnormal movements or postures are predominantly or even exclusively present under specific circumstances [1]. Task-specific oromandibular dystonia (OMD) is a rare condition, and reported exclusively as a result of excessive speech and playing a wind instrument [2–5]. Here we present a case of task-specific OMD following dental implant surgery. A 56-year-old housewife presented with a 1-year history of involuntary retraction of her lips while speaking. She underwent dental implant surgery 6 months earlier, but had neither a relevant medical history nor exposure to relevant medications. She did not have an occupation, hobby or religion requiring an excessive use of perioral muscles. She reported that her symptoms had not progressed after onset. The involuntary movements occurred when she vocalized, regardless of ordinary conservational speech, reading out loud or singing. The lips returned to the normal position immediately after vocalization stopped, and the symptom did not occur while eating or drinking (Video S1). She denied any discomfort in the implant insertion site. This involuntary movement was improved when she put her finger or a depressor on her tongue while speaking, but was not alleviated by chewing gum or sucking on a candy (Video S2). Neurological examination revealed no other neurological deficit. Over a 6-month follow-up, she received medications including procyclidine, metoclopropamide and dantrolene sodium, resulting in mild-to-moderate improvement without progression. Patterned and repeated involvement of the same perioral muscles along with aggravation by voluntary movements are compatible with the clinical characteristics of primary dystonia [1]. The presence of a sensory trick, namely the symptomatic alleviation by touching the tongue, provides additional evidence to diagnose as primary dystonia in this patient [1]. Because her symptom was present exclusively while speaking, it was diagnosed as task-specific OMD. Previously reported cases of speech-induced task-specific OMD were exclusively associated with long-term experiences of excessive speech due to occupation or religious rituals [2– 5], but our patient lacks this association. Peripheral injury, including dental procedures, is a potential predisposing factor to induce OMD [6], but none of the previous cases was task-specific. The causal relationship between dental implants and the development of OMD is unclear. However, OMD in this patient fits the criteria defining peripherally induced OMD suggested by Sankhla et al. [6] well, which include temporal relationship within a year, well documentation of the trauma, and anatomical relationship between the injured site and location of dystonia. The underlying mechanism for task-specific dystonia is still unclear, although deficient central nervous system inhibition, abnormal sensorimotor integration and maladaptive plasticity are suggested [7]. In addition to the longterm overuse of affected muscles, the present case may illustrate another potential relationship between peripheral injury and task-specific OMD.