The Clinical Frailty Scale predicts inpatient mortality in older hospitalised patients with idiopathic Parkinson's disease.

UNLABELLED: Parkinson's disease and frailty are both common conditions affecting older people. Little is known regarding the association of the Clinical Frailty Scale with hospital outcomes in idiopathic Parkinson's disease patients admitted to the acute hospital. We aimed to test whether frailty status was an independent predictor of short-term mortality and other hospital outcomes in older inpatients with idiopathic Parkinson's disease. METHOD: We conducted an observational retrospective study in a large tertiary university hospital between October 2014 and October 2016. Routinely measured patient characteristics included demographics (age and sex), Clinical Frailty Scale, acute illness severity (Emergency Department Modified Early Warning Score), the Charlson Comorbidity Index, discharge specialty, history of dementia, history of depression and the presence of a new cognitive impairment. Outcomes studied were inpatient mortality, death within 30 days of discharge, new institutionalisation, length of stay ≥ 7 days and readmission within 30 days to the same hospital. RESULTS: There were 393 first admission episodes of idiopathic Parkinson's disease patients aged 75 years or more; 166 (42.2%) were female. The mean age (standard deviation) was 82.8 (5.0) years. The mean Clinical Frailty Scale was 5.9 (1.4) and the mean Charlson Comorbidity Index was 1.3 (1.5). After adjustment for covariates, frailty and acute illness severity were independent predictors of inpatient mortality; odds ratio for severely/very severely frail or terminally ill = 8.1, 95% confidence interval 1.0-63.5, p = 0.045 and odds ratio for acute illness severity: 1.3, 95% confidence interval 1.1-1.6, p = 0.005). The Clinical Frailty Scale did not significantly predict other hospital outcomes. CONCLUSIONS: The Clinical Frailty Scale was a significant predictor of inpatient mortality in idiopathic Parkinson's disease patients admitted to the acute hospital and it may be useful as a marker of risk in this vulnerable population

Respiratory dysfunction in Parkinson’s disease

Respiratory dysfunction has been associated with Parkinson’s disease (PD) since it was first described in 1817. The respiratory symptoms observed in PD patients vary greatly. Most patients remain asymptomatic, whereas others present with acute shortness of breath and even stridor. In August 2016, an electronic literature search was conducted using PubMed and Google Scholar. Results were screened and studies reporting on respiratory dysfunction associated with PD were included. Respiratory dysfunction is due to a combination of factors including: restrictive changes; upper airway obstruction; abnormal ventilatory drive; and response to medications. Much debate surrounds the mechanism underlying respiratory dysfunction in PD, its prevalence and the effect of levodopa on respiration. It is clear from this review that larger studies, comparing patients of similar disease duration and severity using the same pulmonary function parameters, are required, to provide a better understanding of the pathophysiology underlying respiratory dysfunction in PD

Bone health in Parkinson's disease: a systematic review and meta-analysis

AJN: Travel support from the National Institute of Health Research for presentations at MDS Congresses and Association of British Neurologists Meetings; grants from Parkinson’s UK Innovation Grant (K-1006), Parkinson’s UK Career Development Award (F-1201), National Institute of Health Research Academic Clinical Fellowship, Élan/Prothena Pharmaceuticals and GE Healthcare. KMD: beneficiary of a Reta Lila Weston Scholarship and received a Parkinson’s UK Innovation Grant (K-1010

Bone health in Parkinson's disease: A systematic review and meta-analysis

Objective: Parkinson's disease (PD) and osteoporosis are chronic diseases associated with increasing age. Single studies have reported associations between them and the major consequence, namely, increased risk of fractures. The aim of this systematic review and meta-analysis was to evaluate the relationship of PD with osteoporosis, bone mineral density (BMD) and fracture risk. Methods: A literature search was undertaken on 4 September 2012 using multiple indexing databases and relevant search terms. Articles were screened for suitability and data extracted where studies met inclusion criteria and were of sufficient quality. Data were combined using standard meta-analysis methods. Results: 23 studies were used in the final analysis. PD patients were at higher risk of osteoporosis (OR 2.61; 95% CI 1.69 to 4.03) compared with healthy controls. Male patients had a lower risk for osteoporosis and osteopenia than female patients (OR 0.45; 95% CI 0.29 to 0.68). PD patients had lower hip, lumbar spine and femoral neck BMD levels compared with healthy controls; mean difference, -0.08, 95% CI -0.13 to -0.02 for femoral neck; -0.09, 95% CI -0.15 to -0.03 for lumbar spine; and -0.05, 95% CI -0.07 to -0.03 for total hip. PD patients were also at increased risk of fractures (OR 2.28; 95% CI 1.83 to 2.83). Conclusions: This systematic review and meta-analysis demonstrate that PD patients are at higher risk for both osteoporosis and osteopenia compared with healthy controls, and that female patients are at greater risk than male patients. Patients with PD also have lower BMD and are at increased risk of fractures. © 2014 by the BMJ Publishing Group Ltd

A service development study of the assessment and management of fracture risk in Parkinson's disease

Parkinson's disease (PD) is associated with an increased risk of fragility fracture. FRAX and Qfracture are risk calculators that estimate the 10-year risk of hip and major fractures and guide definitive investigation for osteoporosis using dual X-ray absorptiometry (DEXA) imaging. It is unclear which PD patients should be considered for fracture risk assessment and whether FRAX or Qfracture should be used. Seventy-seven patients with PD were recruited in the movement disorders clinic. Data were collected on PD-related characteristics and fracture risk scores were calculated. Patients with previous osteoporotic fractures had a higher incidence of falls (p = 0.0026) and use of bilateral walking aids (p = 0.0187) in addition to longer disease duration (p = 0.0037). Selecting patients with falls in combination with either disease duration >5 years, bilateral walking aids, or previous osteoporotic fracture distinguished patients with and without previous osteoporotic fracture with specificity 67.7 % (95 % CI 55.0-78.8) and sensitivity 100.0 % (95 % CI 73.5-100.0). Qfracture calculated significantly higher fracture risk scores than FRAX for hip (p < 0.0001) and major (p = 0.0008) fracture in PD patients. Receiver operating characteristic curves demonstrated that FRAX outperformed Qfracture with an area under the curve of 0.84 (95 % CI 0.70-0.97, p = 0.0004) for FRAX and 0.68 (95 % CI 52-86, p = 0.0476) for Qfracture major fracture risk calculators. We suggest that falls in combination with either a disease duration longer than 5 years or bilateral walking aids or previous osteoporotic fracture should be used as red flags in PD patients to prompt clinicians to perform a FRAX fracture risk assessment in the neurology clinic

A putative relay circuit providing low-threshold mechanoreceptive input to lamina I projection neurons via vertical cells in lamina II of the rat dorsal horn

Background: Lamina I projection neurons respond to painful stimuli, and some are also activated by touch or hair movement. Neuropathic pain resulting from peripheral nerve damage is often associated with tactile allodynia (touch-evoked pain), and this may result from increased responsiveness of lamina I projection neurons to non-noxious mechanical stimuli. It is thought that polysynaptic pathways involving excitatory interneurons can transmit tactile inputs to lamina I projection neurons, but that these are normally suppressed by inhibitory interneurons. Vertical cells in lamina II provide a potential route through which tactile stimuli can activate lamina I projection neurons, since their dendrites extend into the region where tactile afferents terminate, while their axons can innervate the projection cells. The aim of this study was to determine whether vertical cell dendrites were contacted by the central terminals of low-threshold mechanoreceptive primary afferents. Results: We initially demonstrated contacts between dendritic spines of vertical cells that had been recorded in spinal cord slices and axonal boutons containing the vesicular glutamate transporter 1 (VGLUT1), which is expressed by myelinated low-threshold mechanoreceptive afferents. To confirm that the VGLUT1 boutons included primary afferents, we then examined vertical cells recorded in rats that had received injections of cholera toxin B subunit (CTb) into the sciatic nerve. We found that over half of the VGLUT1 boutons contacting the vertical cells were CTb-immunoreactive, indicating that they were of primary afferent origin. Conclusions: These results show that vertical cell dendritic spines are frequently contacted by the central terminals of myelinated low-threshold mechanoreceptive afferents. Since dendritic spines are associated with excitatory synapses, it is likely that most of these contacts were synaptic. Vertical cells in lamina II are therefore a potential route through which tactile afferents can activate lamina I projection neurons, and this pathway could play a role in tactile allodynia

Neuronal circuitry for pain processing in the dorsal horn

Neurons in the spinal dorsal horn process sensory information, which is then transmitted to several brain regions, including those responsible for pain perception. The dorsal horn provides numerous potential targets for the development of novel analgesics and is thought to undergo changes that contribute to the exaggerated pain felt after nerve injury and inflammation. Despite its obvious importance, we still know little about the neuronal circuits that process sensory information, mainly because of the heterogeneity of the various neuronal components that make up these circuits. Recent studies have begun to shed light on the neuronal organization and circuitry of this complex region