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Objective: Prior research suggests that restless leg syndrome (RLS) is prevalent in Parkinson’s disease (PD) with insufficient evidence to support the relationship between RLS, PD, and pain. This study explored the relationship between pain in PD patients and its association with the prevalence and severity of RLS. Method: 127 PD patients were assessed for PD and RLS using the U.K. Brain bank Criteria and the Restless Leg Syndrome diagnostic criteria, respectively. These patients were also assessed for pain perception and interference using the Brief Pain Inventory. Results: The results demonstrated Parkinson’s disease patients who reported pain scored 23 more Restless Leg Syndrome prevalence points ( p < 0.05), and 8.5 counts higher for Restless Leg Syndrome severity ( p < 0.05) compared to the group of Parkinson’s disease patients denying pain. Discussion: The presence of pain in PD patients indicated a higher RLS prevalence and an increased RLS severity. This finding suggests patients suffering from pain interference may experience more severe RLS symptoms. This demonstrates an inextricable link and association between pain in PD patients and RLS. Further robust investigations are required to elucidate any potential causative links, which can inform more holistic treatment principles.

Peripheral neuropathy (PN) is a common neurological problem defined as a dysfunction of sensory, motor, and autonomic nerves. The presence of peripheral neuropathy has recently been noticed in Parkinson's disease (PD) This comorbidity is concerning as it increases the burden on patients whose motor functions are previously compromised. A comprehensive computer-based literature review utilizing multiple peer-reviewed databases (e.g., Embase, PsycINFO, CINAHL, etc.) was conducted. There is evidence for the utility of robust diagnostic criteria to distinguish between large fiber neuropathy (LFN) and small fiber neuropathy (SFN). Some studies have established links between prolonged L-DOPA exposure and prevalence with increased levels of homocysteine (HCY) and methylmalonic acid (MMA) as pathological underlying mechanisms. PN in PD patients with relatively truncated exposure to L-DOPA therapy may have underlying mutations in the Parkin and MHTFR gene or separate mitochondrial disorders. Vitamin B12 and cobalamin deficiencies have also been implicated as drivers of PN. Accumulation of phosphorylated α-synuclein is another central feature in PN and deems urgent exploration via large cohort studies. Importantly, these underlying mechanisms have been linked to peripheral denervation. This review delves into the potential treatments for PN targeting B12 deficiencies and the use of COMT inhibitors along with other novel approaches. Avenues of research with powerful randomized controlled and long-term cohort studies exploring genetic mechanisms and novel treatment pathways is urgently required to alleviate the burden of disease exerted by PN on PD.

Objectives: Although there have been numerous studies conducted to better understand Parkinson’s disease (PD), the epidemiology of its debilitating non-motor symptoms across different ethnicities r...

Among the various non-motor symptoms of Parkinson's disease (PD), pain is often cited as the most common and debilitating feature. Currently, the literature contains gaps in knowledge with respect to the various forms of treatment available, particularly non-pharmacological therapies. Thus, the purpose of this systematic review is to provide an examination of the literature on non-pharmacological therapies for pain in PD. We compared the findings of research articles indexed within various literature databases related to non-pharmacological treatments of pain in PD patients. Our review identified five major non-pharmacological methods of pain therapy in PD: acupuncture, hydrotherapy, massage therapy, neuromodulation, and exercise. Treatments such as exercise therapy found a reduction in pain perception due to various factors, including the analgesic effects of neurotransmitter release during exercise and increased activity leading to a decrease in musculoskeletal rigidity and stiffness. By the same token, hydrotherapy has been shown to reduce pain perception within PD patients, with authors often citing a combined treatment of exercise and hydrotherapy as an effective treatment for pain management. Multiple methods of neurostimulation were also observed, including deep brain stimulation and spinal cord stimulation. Deep brain stimulation showed efficacy in alleviating certain pain types (dystonic and central), while not others (musculoskeletal). Hence, patients may consider deep brain stimulation as an additive procedure for their current treatment protocol. On the other hand, spinal cord stimulation showed significant improvement in reducing VAS scores for pain. Finally, although the literature on massage therapy and acupuncture effectiveness on pain management is limited, both have demonstrated a reduction in pain perception, with common reasons such as tactile stimulation and release of anti-nociceptive molecules in the body. Although literature pertaining to non-pharmacological treatments of pain in PD is sparse, there is copious support for these treatments as beneficial to pain management. Further exploration in the form of clinical trials is warranted to assess the efficacy of such therapies.

Pain is an important non-motor symptom of Parkinson's disease (PD); however, it remains understudied. The purpose of previous studies on the relationship between PD and pain, has been to explore the cause, origin and types of pain. This case control study is designed for clinicians and rehabilitation specialists to effectively identify pain from the patient's point of view. Pain present in PD patients correlates with significant disruption to their daily lives, which was seen by analysing characteristics, frequency, severity and interference of pain.A total of 100 PD patients and 100 control healthy individuals, consisting of 66 males and 34 females were evaluated during routine clinical assessment followed by a neurological exam. The Brief Pain Inventory (BPI) was used to measure chronic pain in terms of pain severity, pain interference and pain frequency between the two groups.It was determined that PD patients had significantly higher pain severity scores compared to controls (p 0.05). PD patients with depressive symptoms had significantly higher pain severity and pain interference scores than controls without depressive symptoms. PD patients reported greater scores on Global BPI pain interference and all components of the pain interference subscale.PD and depression seem to be correlated with higher perceived pain, severity and interference. These findings have not been reported by other case control studies, and warrant further causal research into pain, depression and PD.

Pain, poor sleep quality, restless legs syndrome (RLS), and other symptoms are frequently reported by patients with Parkinson's disease (PD). However, the impact that pain severity and interference has on non-motor symptoms (NMS) has not been extensively studied. The objective of the present study is to explore the relationship between sleep quality in PD to pain and other NMS that affect quality of life.The study included 100 PD patients and 100 age and gender-matched controls assessed for pain severity and pain interference using the Brief Pain Inventory and sleep quality using the Pittsburgh Sleep Quality Index. Participants were also evaluated for their subjective levels of anxiety and depression using the Hospital Anxiety and Depression Scale.PD patients with poor sleep quality had greater pain severity and pain interference than controls and PD patients with good or borderline sleep quality. PD patients with poor sleep quality also had the greatest case-ness and severity for depression and anxiety. However, RLS was not significantly correlated with depression, anxiety or pain.Poor sleep quality in PD patients is related to greater pain severity, pain interference, and more radiating and paresthestic pain that is independent of RLS. There is a higher prevalence of depression and anxiety in PD patients compared to controls, especially in PD patients with poor sleep quality. Our findings suggest a relationship between poor sleep quality in PD with pain, anxiety and depression. Prospective studies are warranted to investigate the causal relationship.

Pain in Parkinson’s disease (PD) is a debilitating symptom with a prevalence of 68%, yet is untreated 50% of the time. What is unclear, however, is which treatment is optimal for minimizing pain severity in PD. Thus, the objective of this systematic review and meta-analysis was to investigate the efficacy of a variety of novel, complimentary, and conventional treatments for pain in PD and elucidate which therapy is the most effective. A systematic search was performed using MEDLINE, PsycINFO, Embase, CINAHL, and CENTRAL databases. To identify additional articles, manual searches of reference lists of included trials were also searched. Major neurology conference proceedings occurring between January 2014 and February 2018 were also searched to identify unpublished studies that may be potentially eligible. Twenty-five randomized controlled trials that encompassed medical, surgical, and complementary therapies met our inclusion criteria and exhibited moderate quality evidence. Two reviewers conducted assessments for study eligibility, risk of bias, data extraction, and quality of evidence rating. A conservative random-effects model was used to pool effect estimates of pain severity. The greatest reductions in pain were found with safinamide (Standardized mean difference = –4.83, 95% CI [–5.07 to –4.59], p < 0.0001), followed by cannabinoids and opioids, multidisciplinary team care, catechol-O-methyltransferase inhibitors, and electrical and Chinese therapies. Moderate effects in reducing pain were in pardoprunox and surgery, while the weakest effects were in dopaminergic agonists and miscellaneous therapies. Safinamide is an important adjunct to standard parkinsonian medication for alleviating pain in PD.

Objective: While much research has been conducted toward understanding the relationship between prevalence of Parkinson's disease (PD) and generalized anxiety, little has been done considering additional influential factors in the relationship by means of a large ethnically diverse sample. Our study strives to fulfill these deficits in the literature as we set out to determine the impact of progression of PD, age, gender, and Hoehn and Yahr (H and Y) staging of PD on generalized anxiety. Methods: A retrospective chart review analysis was performed on PD patients who were regularly examined in a community-based PD and movement disorders center from 2005 to 2010. Results: This study consisted of 310 patients with PD among whom 12% had generalized anxiety. Neither age nor gender was significant onset predictors at P = 0.05. The impact of progression of H and Y Stages 2–3 and 2–4 increased the odds of generalized anxiety disorder (GAD) prevalence though it was statistically insignificant at P = 0.05. Conclusions: Clinicians should not expect the risk of developing anxiety to depend on gender nor change as a function of age though it may increase with symptomatic progression of PD as outlined by H and Y. To the best of our knowledge, this is the largest and most ethnically diverse prevalence study with a focus on generalized anxiety and PD. Significant Outcomes and Limitations: The symptomatic progression of PD, but not age or gender, may be associated with an increased risk for GAD. This study lacked adjustment for potential confounders such as depression and PD medications.

Parkinson's disease (PD) is a neurodegenerative movement disorder characterized by the loss of dopamine containing cells in the substantia nigra, with pain being one of the most common, yet frequently misunderstood symptoms. The prevalence of pain in PD populations ranges from 40-85% and is usually categorized under the following types: i) musculoskeletal pain ii) radicular and neuropathic pain iii) dystonia-related pain iv) akathitic pain and iv) central parkinsonian pain. Areas covered: The aim of this literature review was to document and present the common and uncommon pharmaceutical therapies that treat and/or alleviate these types of pain in PD. The PubMed database was searched with keywords: "Parkinson's disease", "Pain", and "Pharmacological Therapies". Research articles involving randomized, controlled trials were included as well as case studies and qualitative studies. Expert commentary: Given the increased prevalence of pain in PD populations, there is a need for a clear understanding of the types of pain treatments available and how they can be best combined to fit the specific needs of each patient.

Objective: To determine the relationship between resting tremor (RT) and action tremor (AT) in Parkinson’s disease (PD) patients. Methods: A retrospective study of RT and AT severity was conducted in 100 PD patients. The severity rating for each type of tremor in the upper extremities was assessed. The disparity in tremor severity between extremities for each tremor type was compared to that of the other two to identify commonalities in the laterality of the tremor manifestation. Results: Overall, RT is predictive of AT on the same side, but not the opposing side of the body. Patients with less intense resting right upper limb (RRU) tremor and moderately intense RRU tremor were significantly more likely to have an action right upper limb (ARU) tremor (−1.53, P = 0.020; −1.88, P = 0.005, respectively). Similarly, patients with less intense resting left upper limb (RLU) tremor and moderately intense RLU tremors were significantly more likely to have an action left upper limb (ALU) tremor (−3.49, P = 0.000; −1.86, P = 0.017, respectively). In addition, RRU and ALU tremors were associated with an increase in RLU and ARU tremors, respectively. Conclusion: Tremors are common findings in PD patients, and often impair quality of life. By identifying and classifying the relationship between resting and ATs in PD patients, our study sheds light onto the importance of better understanding and future management of this debilitating symptomology.

Many studies have assessed the relationship of depression and anxiety with Parkinson's disease (PD), as well as examining restless leg syndrome (RLS) with depression and anxiety. Nonetheless, there has not been an extensive effort to show how the prevalence of RLS affects both depression and anxiety in PD patients. The objective of this study was to examine how the prevalence of RLS in PD patients affects the prevalence and severity of depression and anxiety and how they compare with each other. This study is the first of its kind that examines the effects of the combination of the two neurological conditions with depression and anxiety as well as comparing their prevalence and severity to each other.The study included 27 PD patients who also suffered from RLS, 27 PD patients not suffering from RLS, and 27 gender-matched healthy individuals. All were evaluated for caseness and severity of both anxiety and depression using the Hospital Anxiety and Depression Scale (HADS); HADS-A and HADS-D, respectively.PD patients with RLS reported having the highest prevalence of both anxiety and depression. The least reported cases for both anxiety and depression were in the control group. In comparison, the results for severity of anxiety and depression within the three groups showed that PD patients with and without RLS had significantly higher severity scores for both anxiety and depression than the control group, but the scores did not significantly differ between the two PD patient groups.The presence of RLS in PD patients may increase the occurrence of both anxiety and depression, but the severity of the symptoms is not significant in the two groups of the PD patients.

Pain is common in atypical parkinsonism such as multiple system atrophy (MSA), progressive supranuclear palsy (PSP), corticobasal degeneration (CBD) and dementia with Lewy bodies (LBD). In this study, a systematic review and meta-analysis was conducted and peer-reviewed literature was searched to determine the prevalence and types of pain in four atypical parkinsonism syndromes: MSA, PSP, CBD and LBD. The results show that pain was prevalent mainly in MSA patients in comparison to PSP and CBD patients. Pain was reported at an early stage and was found in females, with limb pain being the most common, followed by neck and back pain. In comparison to PSP, pain locations were similar to MSA patients. CBD patients experienced pain the least in comparison to MSA, PSP and LBD patients.

Anxiety and depression are common in Parkinson's disease (PD) patients, yet their prevalence and severity compared to individuals without PD requires more research. Moreover, it has never been compared across different ethnic groups. The objective of this study was to close that gap in the literature by exploring the caseness and severity of anxiety and depression in PD patients of different ethnicities compared to controls without PD. It was found that caseness and severity of anxiety and depression are higher in individuals with PD compared to controls. Furthermore, the caseness and severity of anxiety and depression do not vary significantly among ethnic groups. Finally, depression caseness was not predicted by age, gender, disease duration, restless legs syndrome prevalence, Hoehn and Yahr (H&Y) score nor Unified Parkinson's disease rating scale part III (UPDRS-III) score. Anxiety caseness was predicted by gender, with females 2.7 times more likely to have anxiety caseness than males. Overall, our study suggests that treatment plans should be individualized based on prevalence and severity of the two conditions in individuals with PD rather than generalize treatment for specific ethnic groups.

The objectives of the study were to analyze the association between Parkinson's disease and restless legs syndrome, and to explore the relationship between mood disorder comorbidity (anxiety and depression), pain, and restless legs syndrome.This study included 123 Parkinson's disease patients and 123 non-Parkinson's disease patients matched for age and gender, and evaluated for anxiety severity, depression severity, pain severity, pain interference, pain disability, and restless legs syndrome prevalence. This was performed using semi-structured interviews and a neurological examination through the restless legs syndrome diagnostic criteria and the following inventories; Hospital Anxiety and Depression Scale, Brief Pain Inventory, and Pain Disability Index.Parkinson's disease patients had significantly greater anxiety severity, depression severity, pain severity, pain interference, pain disability, and restless legs syndrome prevalence in comparison to controls. In addition, Parkinson's disease patients' comorbid for anxiety and depression had significantly greater pain severity, pain interference, and pain disability, but not RLS prevalence, in comparison to Parkinson's disease only, Parkinson's disease anxiety, and Parkinson's disease depression patients.Pain interference, pain severity, and pain disability is greater among Parkinson's disease patients with anxiety and depression, in comparison to Parkinson's disease patients without anxiety and depression. On the contrary, the prevalence of restless legs syndrome was not found to be relevant.

The objective of the study was to determine whether there exists any relationship between nocturia and anxiety in patients with Parkinson's disease (PD). Although the exact cause of anxiety and nocturia in PD is unknown, we hypothesized that there is a relationship between these two PD symptoms. Anxiety may exacerbate nocturia or an opposite relationship may be present in which nocturia may result in heightened levels of anxiety.Our study consisted of 314 PD patients, selected at random, and divided into groups based on the presence or absence of anxiety and nocturia. The occurrence of anxiety and nocturia was studied individually and collectively within these groups.The study found a significant association between anxiety and nocturia primarily driven by all PD patients (P 0.0001), with greater significance found for the male patients (P 0.0001) than female patients (P = 0.021).Based on these findings, we can conclude that anxiety and nocturia are not entirely independent symptoms in all PD patients. Thus, addressing anxiety may improve nocturia in PD or vice versa.

Alkaptonuria (AKU) is considered a rare autosomal recessive condition that results in an accumulation of homogentisic acid in body tissues and causes long-term clinical, neurological and psychological complications. We present a comprehensive evaluation of an atypical 46-year-old Caucasian male who developed all clinical diagnostic symptoms of AKU (ochronotic pigmentations, dark urine and clinical arthritis of major joints including spine) by 25 years of age, well before the typical age mentioned in many reviews. First signs of ochronotic ear pigmentations unexpectedly started appearing as early as 12 years of age. A long “disease-free” period typical in classical AKU patient was also absent. This case report highlights the importance of considering psychological issues in AKU patients. The patient showed symptoms of dysthymia reporting social isolation, diminished interest in pleasurable activities, feeling of worthlessness and irritability as major psychological issues. Early ochronotic pigmentation, advanced spinal myelopathy and arthropathy of major joints suggests aggressive course of the disease. Our patient underwent bilateral shoulder replacement due to AKU-induced arthropathy resulting in restoration of some range of motions. AKU is not fully understood and we recommend treating it as a multidimensional disease with simultaneous physiological, neurological and psychological effects. Early diagnosis, understanding of disease prognosis and emphasis on psychological health is needed to improve the quality of life of AKU patients.

Context: Late onset Parkinson’s disease (LOPD) is a neurodegenerative disorder afflicting individuals of ages 60 and older. However, 5–10% of cases can begin earlier between the ages 20 to 40, and are classified as young onset Parkinson disease (YOPD). Aim: In turn, this study aims to observe the trend in the choice of drug administered to patients with both YOPD and LOPD, with particular emphasis on this trend in its relation to the practice background of the neurologist. Settings and Design: A cross-sectional study was conducted in a community based Parkinson’s disease and movement disorder clinic. Statistical Analysis Used: Using a retrospective chart review data was obtained and analysed. Results: The results showed that 83% of general neurologists prescribed levodopa to their patients with YOPD, whereas movement-disorder specialists took a different approach altogether. They opted not to use levodopa and, in its stead, prescribed a mixture of alternate drugs.

For the interpretation of EEG, the patient’s condition is described, including whether the patient is awake, has eyes closed or open, and is relaxed or tense. Activation methods are also described.

Nerve conduction studies evaluate neuromuscular disease by providing a neurophysiological assessment of peripheral nerves, neuromuscular junctions, muscles, dorsal root ganglion cells, and anterior horn cells. The peripheral nerve is studied with regard to its pathophysiology and its localization.

Patients having EEG studies for a seizure disorder should be studied when awake as well as while asleep in the same record, since interictal epileptiform activity is increased during sleep and when drowsy . Patients are routinely asked to arrive for the examination after having been sleep-deprived the night before to allow for easy transition to drowsiness.

Sensory nerve conduction studies are an essential part of the electrodiagnostic examination, for several reasons. Some peripheral nerve lesions involve only sensory nerves or only the sensory fibers of mixed nerves. Sensory conduction studies are typically more sensitive than their motor counterparts to pathophysiological processes occurring along mixed nerves. For example, in these mixed nerves, sensory conduction typically occurs before or is more severe than the conduction in the motor components, such as in the segmental demyelinating lesions of carpal tunnel syndrome. Sensory conduction amplitudes are more sensitive to axon loss than ?.

The F-wave is an action potential that is evoked intermittently from a muscle by a supramaximal electrical stimulation of the nerve that is caused by the antidromic activation of motor neurons. The F-wave action potential is approximately 1–5 % that of the M-wave and has a variable configuration. Its latency is longer than that of the M-wave and is variable.

Electroencephalography (EEG) is the noninvasive recording and measuring of the electrical activity of the cerebral cortex, with surface EEG performed via electrodes placed on the scalp. The recorded voltage activity is the net difference between ionic current flows within the brain, controlled by N-methyl-D-aspartate (NMDA) glutamate receptors becoming permeable to calcium ions. An EEG recording is a summation of numerous different frequencies. The depolarization and synchronous activation of many neurons generates epileptiform activity. The spike and wave activity seen in epilepsy is likely caused by cyclic depolarization and repolarization. The inhibiting feedback of the neurons results in the ultimate cessation of the epileptiform activity. The thalamus is considered to be the main site for the origin of cortical excitability. A minimum of 6 cm2 of cortical synchronous activity is needed to create a recordable scalp potential on surface EEG.

Facial neuropathy is the most common cranial neuropathy. The anatomy of the facial nerve is complex, with a long intracranial course. Electrodiagnosis can be helpful in determining prognosis, but such studies are not helpful until several days after the onset of the neuropathy. The clinical presentation shows unilateral weakness of the upper and lower parts of the face, hyperacusis, dysgeusia, and abnormal lacrimation and salivation. Seventy percent of cases are idiopathic, or they can be regarded as Bell’s palsy. Ramsay Hunt syndrome, also known as herpes zoster oticus, is another common cause of facial neuropathy.

Somatosensory evoked potentials (SEPs) are used as an extension of the electrodiagnostic evaluation and nerve conduction tests that are performed in large myelinated sensory fibers of the peripheral and central nervous systems. SEP studies are noninvasive; SEPs are obtained by the repetitive submaximal stimulation of a sensory or mixed sensory/motor peripheral nerve and recording the average responses from electrodes placed over proximal portions of the nerves stimulated in the plexus, spine, and scalp.

Neuromuscular transmission occurs when a quantum of acetylcholine (Ach) from the nerve ending is released and binds to the nicotinic Ach receptors on the postjunctional muscle membrane. The nicotinic Ach receptors on the end plate respond by opening channels to the influx of sodium ions, and subsequent end-plate depolarization leads to muscle contraction. The Ach immediately detaches from the receptor and is hydrolyzed by the enzyme acetylcholinesterase in the synaptic cleft.

Pain is a common problem faced by Parkinson's disease (PD) patients. Despite its impact and disabling effects pain is still frequently overlooked. In this study we analyze a representative sample of peer reviewed literature for the prevalence and types of pain in PD, the impact and significance of pain in the quality of life of the PD patient and the challenges inherent in the diagnosis and management of pain in PD patients. We compared and analyzed the findings of articles indexed in the PubMed database which looked at symptoms reported by large cohorts of PD patients. These articles all reported the incidence, nature and quality of pain in these patients and described the effects of pain on quality of life and generally were cross-sectional, retrospective or case-control studies, though a major pharmacoepidemiological design study was also analyzed. Results of our analysis showed that the pain was prevalent in 59.77% of PD patients. Five different types of pain were reported by PD patients--dystonia, musculoskeletal pain, nerve/nerve root pain, primary/central pain and according to some, akathisia. Patients who reported pain symptoms were also significantly more likely to report associated depression and a decreased quality of life. Many PD patients also reported poor management of pain and lower analgesic use than would be expected. We further discuss some of the possible approaches toward the development of a treatment algorithm regarding the management of pain in PD. We conclude that pain in is an under-recognized and under treated symptom in PD patients. Effective management of pain in PD patients would significantly improve their quality of life. Our analysis is in line with current thinking that identifies PD is much more of a multisystem disease with non-motor symptoms than previously thought.

Aim While much research has been conducted towards understanding the basis of visual hallucinations in Parkinson's disease, little has focused on characterizing the content and patients' emotional experience. These factors are likely very influential on a patient's decision to seek treatment, a critical aspect of any symptom from the clinical perspective. Methods A retrospective chart analysis was performed on Parkinson's disease patients seen in a community-based Parkinson's Disease and Movement Disorder Clinic between 2005 and 2010. Results The study consisted of 334 patients with Parkinson's disease, among whom 10.5% had visual hallucinations. Hoehn and Yahr disease stage (P = 0.001), concurrent presence of dementia (P = 0.001),and sex (P = 0.031) were significant onset predictors. The most significant determinant of treatment-seeking was emotional reaction, namely whether hallucinations were bothersome (P = 0.008). However, the specific type of content during hallucinations was sometimes more influential and contradicted emotional response. Conclusion Although treatment-seeking can be predicted by how individuals feel about hallucinations, a patient's decision may not be logically consistent. We suggest that clinicians offer treatment based on patients' recollections and opinions.

Background: Parkinson's disease (PD) is commonly characterized by its motor symptoms such as resting tremor, rigidity, bradykinesia and postural instability; however, some of the most debilitating symptoms of this disease are non-motor ones such as dementia and sialorrhea (drooling). Drooling is caused by impaired swallowing and it can have a significant impact on the quality of life. However, it is still unclear whether cognitive dysfunction could exacerbate drooling. We wanted to examine if any relationship existed between drooling and dementia in PD patients. Identifying the correlation will aid physicians to screen and initiate early management of drooling in the course of PD. This can possibly lead to improvements in the quality of life in these patients. Methods: In this retrospective study, we investigated the prevalence of drooling in 314 PD patients and further compared the difference in the prevalence of drooling in patients with dementia and without dementia. In addition, we studied the impact of gender on drooling in this patient population. Results: Our results show that a significant correlation exists between drooling and dementia in our sample of PD patients. Furthermore, in males, the correlation between the prevalence of drooling and dementia was found to be clinically significant as compared to the female population. Conclusion: Our findings suggest that drooling is a major concern in the course of PD and should therefore be addressed early and more aggressively in patients with dementia.

In addition to the classic motor symptoms of Parkinson's disease (PD), some patients suffer from a variety of non-motor symptoms. Cognitive deficits such as impairments to learning and memory have been noted in PD and pose a clinical concern. However, during early stages of the disease these deficits may be subtle and difficult to diagnose. To date, various methodologies have been used to identify and diagnose these impairments in PD; imaging studies, animal models, and computer simulated learning paradigms being the most popular. This review discusses the advantages and disadvantages of each method in studying cognitive deficits associated with PD.Imaging studies, including PET and magnetic resonance imaging scans, are useful when studying neural correlates of cognitive tasks. In contrast, toxin-induced and transgenic animal models are well suited for modelling physiological and behavioural conditions observed in humans. Computer simulated learning paradigms are used to analyze cognitive functioning when one engages in a cognitive task.Based on the level of impairment being studied (i.e. neurobiological, behavioural, cognitive basis, or a combination thereof), the use of these methodologies, individually or in conjunction, is imperative when establishing a complete model of PD and its effect on cognition.