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Biomedical subjects

M S Okun

Publications and source records attributed to M S Okun.

At least 19 recordsLinked to original sources
PubMed2006

BDNF tagging polymorphisms and haplotype analysis in sporadic Parkinson's disease in diverse ethnic groups.

Experimental and clinical data suggest that genetic variations in brain-derived neurotrophic factor (BDNF) gene may affect risk for Parkinson's disease (PD). We performed a case-control association analysis of BDNF in three independent Caucasian cohorts (Greek, North American, and Finnish) of PD using eight tagging SNPs and five constructed haplotypes. No statistically significant differences in genotype and allele frequencies were found between cases and controls in all series. A relatively rare BDNF haplotype showed a trend towards association in the Greek (p=0.02) and the Finnish (p=0.03) series (this haplotype was not detected in the North American series). However, given the large number of comparisons these associations are considered non-significant. In conclusion, our results do not provide statistically significant evidence that common genetic variability in BDNF would associate with the risk for PD in the Caucasian populations studied here.

Aged↗
PubMed2006

Limb-kinetic apraxia in Parkinson disease.

To learn if limb-kinetic apraxia (LKA) is associated with Parkinson disease (PD), participants with PD (on medications) and control subjects performed finger tapping (FT), measuring movement speed, and performed coin rotation (CR), measuring precise coordinated but independent finger movements and speed. There were no group differences in FT, a measure of bradykinesia-rigidity, but CR rotation was impaired in PD. Thus, LKA, not related to bradykinesia-rigidity, is associated with PD.

Aged↗
PubMed2006

Dissociating apathy and depression in Parkinson disease.

OBJECTIVE: To examine the hypothesis that apathy is a core feature of Parkinson disease (PD) and that apathy can be dissociated from depression. METHODS: Eighty patients with PD and 20 patients with dystonia completed depression and apathy measures including the Marin Apathy Evaluation Scale (AES), Beck Depression Inventory (BDI), and Centers for Epidemiologic Studies-Depression Scale (CES-D). RESULTS: There was a significantly higher severity and frequency of apathy in PD (frequency = 51%, 41/80) than in dystonia (frequency = 20%, 4/20). Apathy in the absence of depression was frequent in PD and did not occur in dystonia (PD = 28.8%, dystonia = 0%). CONCLUSIONS: Patients with Parkinson disease (PD) experienced significantly higher frequency and severity of apathy when compared with patients with dystonia. Apathy may be a "core" feature of PD and occurs in the absence of depression.

Affective Symptoms↗
PubMed2006

LRRK2 mutations in a clinic-based cohort of Parkinson's disease.

In the last decade, major breakthroughs in the understanding of genetic contributions to Parkinson's disease (PD) have been achieved. Recently, mutations in LRRK2, encoding dardarin, have been found to be responsible for an autosomal dominant parkinsonism (OMIM 607060). We screened 311 subjects (cases: n = 202, controls: n = 109) for the three previously reported LRRK2 mutations. Our investigation revealed a sporadic case of PD with a heterozygous mutation G2019S (c.6055G>A). Here, we present the clinical phenotype of this patient and discuss the implications of genetic testing for the G2019S mutation in patients with sporadic PD.

Adolescent↗
PubMed2006

Panic and fear induced by deep brain stimulation.

BACKGROUND: Mood, cognitive, and behavioural changes have been reported with deep brain stimulation (DBS) in the thalamus, globus pallidus interna, and anterior limb of the internal capsule/nucleus accumbens region. OBJECTIVE: To investigate panic and fear resulting from DBS. METHODS: Intraoperative DBS in the region of the right and then left anterior limb of the internal capsule and nucleus accumbens region was undertaken to treat a 52 year old man with treatment refractory obsessive-compulsive disorder (OCD). Mood, anxiety, OCD, alertness, heart rate, and subjective feelings were recorded during intraoperative test stimulation and at follow up programming sessions. RESULTS: DBS at the distal (0) contact (cathode 0-, anode 2+, pulse width 210 ms, rate 135 Hz, at 6 volts) elicited a panic attack (only seen at the (0) contact). The patient felt flushed, hot, fearful, and described himself as having a "panic attack." His heart rate increased from 53 to 111. The effect (present with either device) was witnessed immediately after turning the device on, and abruptly ceased in the off condition CONCLUSIONS: DBS of the anterior limb of the internal capsule and nucleus accumbens region caused severe "panic." This response may result from activation of limbic and autonomic networks.

Anxiety↗
PubMed2005

Mood and cognitive changes with deep brain stimulation. What we know and where we should go.

AIM: The aim of this study was to completely review the literature on cognitive and mood changes resulting from deep brain stimulation (DBS), and to examine the factors that might lead to these changes. DBS has been shown to improve motor symptoms in many movement disorders. Despite the widespread use of this technique, there are relatively few well controlled studies describing the potential cognitive, mood and behavioral consequences that may result from DBS. Additionally, the factors that may influence these changes have not been carefully studied. METHODS: A complete survey of the articles exploring the effects of DBS on mood and cognition was performed. Each study identified was examined and categories of factors that may have influenced mood and cognition were noted. These factors included surgical target, number of patients studied, whether procedures were unilateral or bilateral, average age of patients, diagnosis, condition of the DBS during the study (on or off), pre-operative screening tests (e.g., dementia rating scale, mini mental state exam), and changes on mood and cognitive tests (categorized as no change, improved, or worsened). Studies were divided into evidence-based categories. RESULTS: There are many mood and cognitive changes that may result from DBS. Due to methodological limitations of existing studies there are important unanswered questions about cognitive and mood changes resulting from this type of surgery. The predominant amount of data regarding changes in mood and cognition with DBS is level 3 or case based evidence. CONCLUSIONS: There exists a paucity of well-controlled studies addressing the mood and cognitive changes that result from DBS. Carefully performed prospective studies may help us to understand the effects of DBS on mood and cognition.

Affect↗
PubMed2004

Important observations prior to the description of the Hoover sign.

OBJECTIVE: To study the context in which Hoover described his sign for differentiating hysterical and organic hemiplegia. BACKGROUND: At the turn of the 20th century, many physicians were looking for signs to distinguish organic from hysterical hemiparesis. In 1908, Hoover described his sign of "complementary opposition." Other signs based on associated movements of the upper extremities, lower extremities, and trunk were also described during and before this period and might have contributed to Hoover's understanding of complementary opposition. METHODS: A complete literature review of the original relevant articles by Babinski, Bychowski, Grasset and Gaussel, and Hoover was performed. RESULTS: Several similar maneuvers were described before the Hoover sign. Babinski described the trunk-thigh test in 1897. Bychowski in Warsaw (performed since 1902, published in 1907) and Grasset and Gaussel in Paris (1905) independently described a phenomenon in which the separate elevation of each leg was performed more easily than simultaneous elevation. Moreover, Bychowski, although not emphasizing it as a sign, described what became known as Hoover sign. Hoover sign (1908) has been considered a further elaboration of these previous observations. Interestingly, Hoover had studied in Europe, and although no direct relationship between his discovery and these observations has been elucidated, the authors postulate that he was influenced by Babinski, Bychowski, and Grasset and Gaussel. CONCLUSION: Although Babinski, Bychowski, and Grasset and Gaussel described similar signs, only Hoover sign is still in wide use by practitioners.

Hemiplegia↗
PubMed2004

Development and initial validation of a screening tool for Parkinson disease surgical candidates.

As there is currently no standardized assessment tool for evaluating Parkinson disease (PD) patients for deep brain stimulation (DBS), the authors developed the Florida Surgical Questionnaire for Parkinson Disease (FLASQ-PD). Part I of the study was a retrospective analysis of 174 patients presenting for a surgical screening. Part II was a multicenter study to assess the correlation of FLASQ-PD scores. The results of this study suggest that the FLASQ-PD may be a useful triage tool for screening PD patients for DBS surgery.

Deep Brain Stimulation↗
PubMed2004

Plasma testosterone levels in Alzheimer and Parkinson diseases.

BACKGROUND: Testosterone deficiency, a treatable condition commonly seen in aging men, has been linked to Parkinson disease (PD) and Alzheimer disease (AD). In normal subjects, low testosterone levels are associated with cognitive and neuropsychiatric symptoms, yet the relationship between testosterone levels and cognitive function in PD and AD remains unclear. OBJECTIVE: To examine the relationship of testosterone levels to age and cognitive function in PD and AD. METHODS: Plasma testosterone levels were determined in men enrolled in a clinical registry of subjects with PD and AD, and neuropsychological testing was performed on subjects who consented. Testosterone levels in men with PD were compared with those in men with AD. In both groups, the relationship between testosterone levels and neuropsychological test scores was analyzed, adjusting for age and education. RESULTS: Linear regression analysis revealed that testosterone levels decreased with age in male PD patients (p < 0.03) and male AD patients (p < 0.07). The rate of decline was similar for the two groups. In PD patients, lower testosterone levels were associated with poorer performance on Trails B Seconds (p < 0.02). CONCLUSIONS: There is a similar age-related decline in plasma testosterone levels in men with either PD or AD. Previously described associations between low testosterone levels and frontal lobe dysfunction in normal aged men, together with these results, suggest that the hormonal deficiency may act as a "second hit" to impair cognitive function in neurodegenerative disease.

Adult↗
PubMed2004

Pseudobulbar crying induced by stimulation in the region of the subthalamic nucleus.

We describe a case of pseudobulbar crying associated with deep brain stimulation (DBS) in the region of the subthalamic nucleus (STN). Patients with pseudobulbar crying show no other evidence of subjective feelings of depression such as dysphoria, anhedonia, or vegetative signs. This may be accompanied by other symptoms of pseudobulbar palsy and has been reported to occur with ischaemic or structural lesions in both cortical and subcortical regions of the brain. Although depression has been observed to result from DBS in the region of the STN, pseudobulbar crying has not been reported. A single patient who reported the symptoms of pseudobulbar crying after placement of an STN DBS was tested in the off DBS and on DBS conditions. The patient was tested using all four DBS lead contacts and the observations and results of the examiners were recorded. The Geriatric Depression Scale was used to evaluate for depression in all of the conditions. The patient exhibited pseudobulbar crying when on monopolar stimulation at all four lead contacts. The pseudobulbar crying resolved off stimulation. This case describes another type of affective change that may be associated with stimulation in the region of or within the STN. Clinicians should be aware of this potential complication, the importance of differentiating it from stimulation induced depression, and its response to a serotonin reuptake inhibitor, such as sertraline.

Crying↗
PubMed2003

Mood changes with deep brain stimulation of STN and GPi: results of a pilot study.

The results of this study suggest that there are mood changes associated with deep brain stimulation of the subthalamic nucleus (STN) and the globus pallidus interna (GPi). Further, optimal placement of electrodes in both STN and GPi seems to result in overall improvement in mood and is associated with a lower incidence of adverse mood effects than stimulation outside the optimal site. Preliminary data from this study, however, suggest that slight movement dorsal or ventral to the site of optimal motor performance may be associated with more adverse changes in mood with STN stimulation than with GPi stimulation.

Aged↗
PubMed2001

Treatment of ballism and pseudobulbar affect with sertraline.

BACKGROUND: The pathogenesis of ballism is uncertain and may involve more than one mechanism; treatment is not always efficacious. OBJECTIVE: To provide evidence of a nondopaminergic mechanism and the potential for a prompt and nearly complete response to a serotonergic agent. METHODS: Report of 2 separate trials of sertraline hydrochloride in a single patient. RESULTS: Complete remission of symptoms within 48 hours of each drug trial. CONCLUSION: Sertraline may offer an alternative with a better adverse effect profile than dopamine receptor blockers in the treatment of patients with ballism.

Aged↗
PubMed2001

Complications of gamma knife surgery for Parkinson disease.

BACKGROUND: Many medical centers throughout the world offer radiosurgery with the gamma knife (GK) for pallidotomy and thalamotomy as a safe and effective alternative to radiofrequency ablative surgery and deep brain stimulation for Parkinson disease (PD). The reported incidence of significant complications varies considerably, and the long-term complication rate remains unknown. DESIGN: We describe 8 patients seen during an 8-month period referred for complications of GK surgery for PD. RESULTS: Of the 8 patients, 1 died as a result of complications, including dysphagia and aspiration pneumonia. Other complications included hemiplegia, homonymous visual field deficit, hand weakness, dysarthria, hypophonia, aphasia, arm and face numbness, and pseudobulbar laughter. In all patients, lesions were significantly off target. CONCLUSIONS: The 8 patients with PD seen in referral at our center for complications of GK surgery highlight a spectrum of potential problems associated with this procedure. These include lesion accuracy and size and the delayed development of neurological complications secondary to radiation necrosis. Gamma knife surgery may have a higher complication rate than has been previously appreciated due to delayed onset and underreporting. We believe that the risk-benefit ratio of the GK will require further scrutiny when considering pallidotomy or thalamotomy in patients with PD. Physicians using this technique should carefully follow up patients postoperatively for delayed complications, and fully inform patients of these potential risks.

Aged↗