Roneil Malkani

The dardarin G2019S mutation is a common cause of Parkinson's disease but not other neurodegenerative diseases

Mutations in the leucine-rich kinase 2 gene (LRRK 2) encoding dardarin, on chromosome 12, are a common cause of familial and sporadic Parkinsons disease. The most common mutation, a heterozygous 6055 G>A transition (G 2019 S) accounts for approximately 3--10% of familial Parkinsons disease and 1--8% sporadic Parkinsons disease in several European-derived populations. Some families with disease caused by LRRK 2 mutations have been reported to include patients with highly variable clinical and pathological features. We screened for the most common LRRK 2 mutation in a series of patients with Parkinsons Disease, Alzheimers disease, Progressive Supranuclear Palsy, Multiple System Atrophy and frontotemporal dementia, as well as in neurologically normal controls. The mutation was found only in Parkinsons disease patients or their relatives and not in those with other neurodegenerative disease.

Bing–Neel syndrome: an illustrative case and a comprehensive review of the published literature

Waldenstrom’s macroglobulinemia (WM) is a chronic lymphoproliferative disorder within the spectrum of lymphoplasmacytic lymphoma characterized by proliferation of plasma cells, small lymphocytes, and plasmacytoid lymphocytes. Central nervous system involvement is very rare (Bing–Neel [BN] syndrome). We present the case of a 62-year-old woman previously diagnosed with WM who presented with Bing–Neel syndrome and review the published literature which consists of only case reports. We performed a Medline search using the terms “Waldenstrom’s macroglobulinemia and central nervous system” and “Bing–Neel” collecting data on presentation, evaluation, treatment, and outcome and summarizing these findings in the largest pooled series to date. Central nervous system manifestations are localization related. Serum laboratory testing reflects systemic disease. Cerebrospinal fluid analysis may show lymphocytic pleocytosis, elevated protein, and IgM kappa or lambda light chain restriction; cytology results are variable. Imaging is frequently abnormal. Biopsy confirms the diagnosis. Treatment data are limited, but responses are seen with radiation and/or chemotherapy. BN syndrome is a very rare complication of WM that should be considered in patients with neurologic symptoms and a history of WM. Treatment should be initiated as responses do occur that may improve quality of life and extend it when limited or no active systemic disease is present.

Clinical features of patients with blepharospasm: A report of 240 patients

Background and purpose:  To characterize patients with benign essential blepharospasm (BEB) by diagnosis, environmental risk factors, and family history.

Amantadine for freezing of gait in patients with Parkinson disease.

BackgroundFreezing of gait (FOG) is a common symptom in patients with advanced Parkinson’s disease (PD) representing a major cause of disability and falls. Although the pathophysiology of FOG remains poorly understood, nondopaminergic pathways have been implicated. Treatment studies of levodopa and selegiline have shown limited benefit for FOG. Limited data suggest that amantadine, an N-methyl-D-aspartate receptor antagonist, may be beneficial for FOG in PD. ObjectiveTo examine the relationship between treatment with oral amantadine and FOG in patients with PD. MethodsWe conducted a retrospective chart review of PD patients who received amantadine specifically for FOG and had a follow-up assessment of FOG. The primary outcome measure was self-reported effectiveness of amantadine (improvement, worsening, or no change in FOG) based on records from the follow-up assessment. ResultsEleven patients with PD with median age of PD onset of 67 years (range, 51–84 years) and median Hoehn and Yahr stage 3 (range, 2–4) met the study population selection criteria. Ten of 11 patients reported improvement in FOG after initiation of amantadine, whereas FOG worsened in one patient. Median amantadine dosage was 100 mg twice daily, and treatment duration was 20 months (range, 6–66 months). Four patients reported reduction in benefit after 4 months. Three patients reported adverse effects, including blurred vision, visual hallucinations, and peripheral edema; the latter 2 effects resulted in discontinuation of amantadine. ConclusionAmantadine is associated with self-reported improvement in FOG in PD, but this effect may be transient. Further studies, including a randomized placebo-controlled trial, are needed to better evaluate this association.

Acoustic Enhancement of Sleep Slow Oscillations and Concomitant Memory Improvement in Older Adults

Acoustic stimulation methods applied during sleep in young adults can increase slow wave activity (SWA) and improve sleep-dependent memory retention. It is unknown whether this approach enhances SWA and memory in older adults, who generally have reduced SWA compared to younger adults. Additionally, older adults are at risk for age-related cognitive impairment and therefore may benefit from non-invasive interventions. The aim of this study was to determine if acoustic stimulation can increase SWA and improve declarative memory in healthy older adults. Thirteen participants 60–84 years old completed one night of acoustic stimulation and one night of sham stimulation in random order. During sleep, a real-time algorithm using an adaptive phase-locked loop modeled the phase of endogenous slow waves in midline frontopolar electroencephalographic recordings. Pulses of pink noise were delivered when the upstate of the slow wave was predicted. Each interval of five pulses (“ON interval”) was followed by a pause of approximately equal length (“OFF interval”). SWA during the entire sleep period was similar between stimulation and sham conditions, whereas SWA and spindle activity were increased during ON intervals compared to matched periods during the sham night. The increases in SWA and spindle activity were sustained across almost the entire five-pulse ON interval compared to matched sham periods. Verbal paired-associate memory was tested before and after sleep. Overnight improvement in word recall was significantly greater with acoustic stimulation compared to sham and was correlated with changes in SWA between ON and OFF intervals. Using the phase-locked-loop method to precisely target acoustic stimulation to the upstate of sleep slow oscillations, we were able to enhance SWA and improve sleep-dependent memory storage in older adults, which strengthens the theoretical link between sleep and age-related memory integrity.

Phase-locked loop for precisely timed acoustic stimulation during sleep

BACKGROUND A brain-computer interface could potentially enhance the various benefits of sleep. NEW METHOD We describe a strategy for enhancing slow-wave sleep (SWS) by stimulating the sleeping brain with periodic acoustic stimuli that produce resonance in the form of enhanced slow-wave activity in the electroencephalogram (EEG). The system delivers each acoustic stimulus at a particular phase of an electrophysiological rhythm using a phase-locked loop (PLL). RESULTS The PLL is computationally economical and well suited to follow and predict the temporal behavior of the EEG during slow-wave sleep. COMPARISON WITH EXISTING METHODS Acoustic stimulation methods may be able to enhance SWS without the risks inherent in electrical stimulation or pharmacological methods. The PLL method differs from other acoustic stimulation methods that are based on detecting a single slow wave rather than modeling slow-wave activity over an extended period of time. CONCLUSIONS By providing real-time estimates of the phase of ongoing EEG oscillations, the PLL can rapidly adjust to physiological changes, thus opening up new possibilities to study brain dynamics during sleep. Future application of these methods hold promise for enhancing sleep quality and associated daytime behavior and improving physiologic function.

Morning and Evening Blue-Enriched Light Exposure Alters Metabolic Function in Normal Weight Adults

Increasing evidence points to associations between light-dark exposure patterns, feeding behavior, and metabolism. This study aimed to determine the acute effects of 3 hours of morning versus evening blue-enriched light exposure compared to dim light on hunger, metabolic function, and physiological arousal. Nineteen healthy adults completed this 4-day inpatient protocol under dim light conditions (<20lux). Participants were randomized to 3 hours of blue-enriched light exposure on Day 3 starting either 0.5 hours after wake (n = 9; morning group) or 10.5 hours after wake (n = 10; evening group). All participants remained in dim light on Day 2 to serve as their baseline. Subjective hunger and sleepiness scales were collected hourly. Blood was sampled at 30-minute intervals for 4 hours in association with the light exposure period for glucose, insulin, cortisol, leptin, and ghrelin. Homeostatic model assessment of insulin resistance (HOMA-IR) and area under the curve (AUC) for insulin, glucose, HOMA-IR and cortisol were calculated. Comparisons relative to baseline were done using t-tests and repeated measures ANOVAs. In both the morning and evening groups, insulin total area, HOMA-IR, and HOMA-IR AUC were increased and subjective sleepiness was reduced with blue-enriched light compared to dim light. The evening group, but not the morning group, had significantly higher glucose peak value during blue-enriched light exposure compared to dim light. There were no other significant differences between the morning or the evening groups in response to blue-enriched light exposure. Blue-enriched light exposure acutely alters glucose metabolism and sleepiness, however the mechanisms behind this relationship and its impacts on hunger and appetite regulation remain unclear. These results provide further support for a role of environmental light exposure in the regulation of metabolism.

Pharmacotherapy of Apnea by Cannabimimetic Enhancement, the PACE Clinical Trial: Effects of Dronabinol in Obstructive Sleep Apnea

Study Objectives There remains an important and unmet need for fully effective and acceptable treatments in obstructive sleep apnea (OSA). At present, there are no approved drug treatments. Dronabinol has shown promise for OSA pharmacotherapy in a small dose-escalation pilot study. Here, we present initial findings of the Phase II PACE (Pharmacotherapy of Apnea by Cannabimimetic Enhancement) trial, a fully blinded parallel groups, placebo-controlled randomized trial of dronabinol in people with moderate or severe OSA. Methods By random assignment, 73 adults with moderate or severe OSA received either placebo (N = 25), 2.5 mg dronabinol (N = 21), or 10 mg dronabinol (N = 27) daily, 1 hour before bedtime for up to 6 weeks. Results At baseline, overall apnea-hypopnea index (AHI) was 25.9 ± 11.3, Epworth Sleepiness Scale (ESS) score was 11.45 ± 3.8, maintenance of wakefulness test (MWT) mean latency was 19.2 ± 11.8 minutes, body mass index was 33.4 ± 5.4 kg/m2, and age was 53.6 ± 9.0 years. The number and severity of adverse events, and treatment adherence (0.3 ± 0.6 missed doses/week) were equivalent among all treatment groups. Participants receiving 10 mg/day of dronabinol expressed the highest overall satisfaction with treatment (p = .04). In comparison to placebo, dronabinol dose-dependently reduced AHI by 10.7 ± 4.4 (p = .02) and 12.9 ± 4.3 (p = .003) events/hour at doses of 2.5 and 10 mg/day, respectively. Dronabinol at 10 mg/day reduced ESS score by -3.8 ± 0.8 points from baseline (p < .0001) and by -2.3 ± 1.2 points in comparison to placebo (p = .05). MWT sleep latencies, gross sleep architecture, and overnight oxygenation parameters were unchanged from baseline in any treatment group. Conclusions These findings support the therapeutic potential of cannabinoids in people with OSA. In comparison to placebo, dronabinol was associated with lower AHI, improved self-reported sleepiness, and greater overall treatment satisfaction. Larger scale clinical trials will be necessary to clarify the best potential approach(es) to cannabinoid therapy in OSA.

Alternative treatment of restless legs syndrome: an overview of the evidence for mind–body interventions, lifestyle interventions, and neutraceuticals

Conventional pharmacologic treatment of restless legs syndrome (RLS) may be limited in some people. Up to 65% of patients with RLS regularly use alternative practices for symptom relief. We reviewed the current clinical evidence, and we proposed physiologic basis for various alternative practices for RLS including mind-body interventions (conventional exercise, yoga, and acupuncture), non-pharmacologic lifestyle interventions (pneumatic compression devices [PCDs], light therapy, and cognitive-behavioral therapy [CBT]), and neutraceuticals (vitamins, valerian, and Chinese herbs). Based on the available evidence, regular physical activity should be recommended for the treatment of RLS symptoms. Oral iron supplementation should be considered for people with RLS who have low ferritin levels, although criteria to identify probable responders, and optimal formulations and durations of treatment are needed. Supplementation for low levels of vitamins E, C, and D could be considered, although evidence specifically in RLS is limited, and it is unclear if levels should routinely be checked in patients with RLS. Insufficient evidence exists for yoga, acupuncture, PCDs, near-infrared light therapy, CBT, valerian, or Chinese herbs, but preliminary studies on each of these suggest that high-quality randomized controlled trials may be warranted to support and verify the data presented.

Ataxia and cranial neuropathies from subcutaneously injected elemental mercury

Context. Although neurological toxicity from elemental mercury vapor and organic mercury exposure has been commonly reported in the literature, it is rarely reported from soft tissue injection of elemental mercury. We present a case of neurological dysfunction from subcutaneous injection of elemental mercury. Case details. A 35‐year‐old Latin American man subacutely developed gait ataxia, diplopia, and vomiting 1 year after subcutaneous injection of elemental mercury, a practice common in Afro‐Caribbean and Latin‐American cultures. Physical examination showed an indurated plaque on his right shoulder at the injection site, left third nerve and bilateral sixth nerve palsies, nystagmus, dysarthria, and gait and limb ataxia. The patient’s serum and 24‐h urine mercury levels were significantly elevated; he underwent excision of the mercury reservoir and chelation with dimercaptosuccinic acid but experienced only mild improvement after 1 year. Discussion. Neurological sequelae from elemental mercury, specifically cognitive dysfunction, tremor, cortical myoclonus, and peripheral neuropathy, have been reported but cranial neuropathies, ataxia, cerebrospinal fluid pleocytosis, and the presence of anti‐Purkinje cell type‐Tr antibody have not. Treatment involves removal of any existing mercury reservoir and chelation; however, improvement in neurological dysfunction after treatment has rarely been reported in the literature.