Pure Autonomic Failure-A Localized Alpha Synucleinopathy with a Potential for Conversion to More Extensive Alpha Synucleinopathies

Pure autonomic failure (PAF) is an alpha synucleinopathy with predominant involvement of the autonomic ganglia and peripheral nerves. The hallmark clinical feature is orthostatic hypotension. However, genitourinary, sudomotor, and cardiac involvement is also common. Many patients also develop supine hypertension. Almost a quarter of patients can phenoconvert or evolve into Parkinson's disease, multiple system atrophy, and Lewy body dementia in the future. Early severe bladder involvement, higher supine noradrenaline level, early motor involvement, and dream enactment behavior increase the risk of phenoconversion. The diagnosis is confirmed via autonomic function testing and serum noradrenaline measurement. The treatment is mainly supportive. The non-pharmacological treatment includes adequate fluid, dietary salt, compression stockings, and abdominal binders. The drug therapies to improve blood pressure include midodrine, fludrocortisone, pyridostigmine, and droxidopa. The diagnostic criteria need to be updated to incorporate the recent understandings. The treatment of orthostatic hypotension and supine hypertension is mainly based on case series and anecdotal reports. Randomized control trials are needed to ascertain the best treatment strategies for PAF.

Pure autonomic failure

Pure autonomic failure is a degenerative disorder of the peripheral autonomic nervous system. Patients experience symptomatic hypotension that requires them to sit, squat or lie down to prevent syncope. It is associated with characteristic histopathological findings, resulting in neuronal cytoplasmic inclusions in the peripheral autonomic nerves. These lesions are responsible for defects in the synthesis and release of norepinephrine from sympathetic nerve terminals, resulting in significant hypotension. Patients with autonomic failure also have exaggerated blood pressure responses to common stimuli such as food or fluid intake, heat, exercise and medications. Tilt table (head-up) testing is probably the test most commonly used to establish the diagnosis. However, simple office testing is also useful, such as having the patient stand after lying supine with blood pressure monitoring. Treatment options range from simply increasing fluid and salt intake, and using compressive garments, to medications administered orally, subcutaneously or intravenously in more severe cases.

Hypertension in the Kidney Transplant Recipient: Overview of Pathogenesis, Clinical Assessment, and Treatment

Cardiovascular disease is the leading cause of death in patients with chronic renal disease and the most common cause of death and allograft loss among kidney transplant recipients. Transplant patients often have multiple cardiovascular risk factors antedating transplantation. Among the most prominent is hypertension (HTN), which affects at least 90% of transplant patients. Uncontrolled HTN is an independent risk factor for allograft loss. The etiology of HTN in transplant recipients is complex and multifactorial, including the use of essential immunosuppressive medications. Post-transplant HTN management requires a systematic and individualized approach with nonpharmacologic and pharmacologic therapies. There is no single ideal agent or treatment algorithm. Patients should regularly monitor and record their blood pressure at home. Often, multiple antihypertensive drugs are needed to achieve a goal blood pressure of 120-140/70-90 mm Hg. As transplant recipients commonly must take 8 to 12 different medications daily, adherence must be continually encouraged and monitored. Special attention must be paid to potential drug side effects and drug interactions with immunosuppressive medications.

What Should Be the Target Blood Pressure in Elderly Patients With Diabetes?

Hypertension is very common in elderly subjects with type 2 diabetes. The coexistence of hypertension and diabetes can be devastating to the cardiovascular system, and in these patients, tight blood pressure (BP) control is particularly beneficial. Little information is available regarding the target BP levels in elderly hypertensive patients with type 2 diabetes, and therefore extrapolation from data in the general population should be done. However, it is difficult to extrapolate from the general population to these frail individuals, who usually have isolated systolic hypertension, comorbidities, organ damage, cardiovascular disease, and renal failure and have a high rate of orthostatic and postprandial hypotension. On the basis of the available evidence, we provide arguments supporting the individualized approach in these patients. Target BP should be based on concomitant diseases, orthostatic BP changes, and the general condition of the patients. It is recommended to lower BP in the elderly patient with diabetes to <140-150/90 mmHg, providing the patient is in good condition. In patients with isolated systolic hypertension, the same target is reasonable providing the diastolic BP is >60 mmHg. In patients with coronary artery disease and in patients with orthostatic hypotension, excessive BP lowering should be avoided. In elderly hypertensive patients with diabetes, BP levels should be monitored closely in the sitting and the standing position, and the treatment should be tailored to prevent excessive fall in BP.

New developments in the management of neurogenic orthostatic hypotension

Orthostatic hypotension (OH) is defined as a sustained reduction of ≥ 20 mmHg systolic blood pressure or ≥ 10 mmHg diastolic blood pressure upon standing for ≤ 3 min. Orthostatic hypotension is commonly associated with hypertension, and its prevalence is highest in those with uncontrolled hypertension compared to those with controlled hypertension or normotensive community elderly subjects. Orthostatic hypotension can cause significant disability, with patients experiencing dizziness, lightheadedness or syncope, and other problems that potentially have a profound negative impact on activities of daily living that require standing or walking. Furthermore, OH increases the risk of falls and, importantly, is an independent risk factor of mortality. Despite its importance, there is a paucity of treatment options for this condition. Most of the advances in treatment options have relied on small studies of repurposed drugs done in patients with severe OH due to rare neurodegenerative conditions. Midodrine, an oral prodrug converted to the selective α1-adrenoceptor agonist desglymidodrine, was approved by the FDA for the treatment of OH in 1996. For almost two decades, no other pharmacotherapy was developed specifically for the treatment of OH until 2014, when droxidopa was approved by the FDA for the treatment of neurogenic OH associated with primary autonomic neuropathies including Parkinson disease, multiple system atrophy, and pure autonomic failure. These are neurodegenerative diseases ultimately characterized by failure of the autonomic nervous system to generate norepinephrine responses appropriate to postural challenge. Droxidopa is a synthetic amino acid that is converted to norepinephrine by dopa-decarboxylase, the same enzyme that converts levodopa into dopamine in the treatment of Parkinson disease. We will review this and other advances in the treatment of OH in an attempt to provide a practical guide to its management.

Orthostatic blood pressure test for risk stratification in patients with hypertrophic cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is the most common cause of sudden cardiac death (SCD) in young adults, mainly ascribed to ventricular tachycardia (VT). Assuming that VT is the major cause of (pre-) syncope in HCM patients, its occurrence is essential for SCD risk stratification and primarily preventive ICD-implantation. However, evidence of VT during syncope is often missing. As the differentiation of potential lethal causes for syncope such as VT from more harmless reasons is crucial, HCM patients were screened for orthostatic dysregulation by using a simple orthostatic blood pressure test.

METHODS

Over 15 months (IQR [9;20]) 100 HCM patients (55.8±16.2 yrs, 61% male) were evaluated for (pre-)syncope and VT (24h-ECGs, device-memories) within the last five years. Eighty patients underwent an orthostatic blood pressure test. Logistic regression models were used for statistical analysis.

RESULTS

In older patients (>40 yrs) a positive orthostatic test result increased the chance of (pre-) syncope by a factor of 63 (95%-CI [8.8; 447.9], p<0.001; 93% sensitivity, 95%-CI [76; 99]; 74% specificity, 95%-CI [58; 86]). No correlation with VT was shown. A prolonged QTc interval also increased the chance of (pre-) syncope by a factor of 6.6 (95%-CI [2.0; 21.7]; p=0.002).

CONCLUSIONS

The orthostatic blood pressure test is highly valuable for evaluation of syncope and presyncope especially in older HCM patients, suggesting that orthostatic syncope might be more relevant than previously assumed. Considering the high complication rates due to ICD therapies, this test may provide useful information for the evaluation of syncope in individual risk stratification and may help to prevent unnecessary device implantations, especially in older HCM patients.

Drug therapies in older adults (part 2)

In this, the second of two articles, we continue our evaluation of drug therapies in older adults. Having previously described the pharmacokinetic and pharmacodynamic consequences of physiological ageing, along with the challenge of appropriate prescribing, we proposed four key questions which should be considered when prescribing for this cohort of the population. Does this agent reflect the priorities of the patient? Are there alternatives - with greater efficacy, effectiveness or tolerability - that might be considered? Are the dose, frequency and formulation appropriate? How does this prescription relate to concurrent medication? We also highlighted the reliance on subgroup analysis to demonstrate the efficacy of drug therapies for older adults in osteoporosis and the underutilisation of appropriate treatments for patients with Alzheimer's disease as a result of flawed guidelines. Here we describe current drug therapies in systolic heart failure, noting the limited inclusion of older adults in key trials, while also reviewing the pharmacological treatment of orthostatic hypotension. In doing so, we advocate the intermittent use of midodrine as a first-line treatment for orthostasis in older adults, counter to the generic guidelines produced by various learned societies, but in keeping with the scant trial data available.

Orthostatic hypotension in patients with dementia: clinical features and response to treatment

OBJECTIVE

To evaluate orthostatic hypotension (OH) prevalence, risk factors, signs and symptoms, and treatment response in patients with dementia.

BACKGROUND

No previous studies had systematically delineated the clinical features of OH in patients with dementia and determined the effects of treatment. Diagnosing this treatable disorder may prevent the severe consequences of falls, syncope, confusion, ischemic brain injury, and death; mortality risk rises with worsening OH. Lesser consequences include skin injuries, sprains, fractures, and subdural hematomas.

METHODS

We reviewed the charts of 188 patients with dementia who had been treated by author D.F., a solo neurologist/neurobehaviorist. About half of the patients had been diagnosed with OH. D.F. had treated the OH until the patients had much improved blood pressure and symptoms, were asymptomatic, or no longer met OH diagnostic criteria. We collected data on diagnoses, blood pressures, and clinical features before and after treatment.

RESULTS

Our patients' most frequent OH signs and symptoms were mental fluctuations (65.6% of patients), excessive sleeping in chairs (29.2%), slow falls without losing consciousness (20.8%), lethargy or fatigue (15.6%), and dizziness (13.5%). All 5 of these signs and symptoms improved significantly with treatment.

CONCLUSIONS

Patients with dementia were less likely to have traditional OH symptoms like dizziness than to have mental fluctuations and confusion, drowsiness, and slow falls. Blaming these problems on worsening dementia and neglecting OH as a potential cause may delay diagnosis and specific treatments that can improve patients' safety, daily function, and quality of life.

Cardiovascular status of individuals with incomplete spinal cord injury from 7 NeuroRecovery Network rehabilitation centers

OBJECTIVE

To examine cardiovascular (CV) health in a large cohort of individuals with incomplete spinal cord injury (SCI). The CV health parameters of patients were compared based on American Spinal Injury Association Impairment Scale (AIS), neurologic level, sex, central cord syndrome, age, time since injury, Neuromuscular Recovery Scale, and total AIS motor score.

DESIGN

Cross-sectional study.

SETTING

Seven outpatient rehabilitation clinics.

PARTICIPANTS

Individuals (N=350) with incomplete AIS classification C and D were included in this analysis.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Heart rate, systolic and diastolic blood pressure during resting sitting and supine positions and after an orthostatic challenge.

RESULTS

CV parameters were highly variable and significantly differed based on patient position. Neurologic level (cervical, high and low thoracic) and age were most commonly associated with CV parameters where patients classified at the cervical level had the lowest resting CV parameters. After the orthostatic challenge, blood pressure was highest for the low thoracic group, and heart rate for the high thoracic group was higher. Time since SCI was negatively related to blood pressure at rest but not after orthostatic challenge. Men exhibited higher systolic blood pressure than women and lower heart rate. The prevalence of orthostatic hypotension (OH) was 21% and was related to the total motor score and resting seated blood pressures. Cervical injuries had the highest prevalence.

CONCLUSIONS

Resting CV parameters of blood pressure and heart rate are affected by position, age, and neurologic level. OH is more prevalent in cervical injuries, those with lower resting blood pressures and who are lower functioning. Results from this study provide reference for CV parameters for individuals with incomplete SCI. Future research is needed on the impact of exercise on CV parameters.