24-Hour Ambulatory Blood Pressure Monitoring in SWEDDs Patients With Parkinsonism

Twenty-four hour blood pressure profile in idiopathic REM sleep behaviour disorder

STUDY OBJECTIVES

To determine whether autonomic dysfunction in idiopathic REM sleep behaviour disorder (iRBD) affects circadian blood pressure (BP) profile.

METHODS

21 iRBD (mean age 68.8±6.4, mean age at onset 62.2±9.3), 21 drug-free de novo Parkinson's disease (PD) subjects and 21 control subjects (HCs), comparable for age and sex, underwent 24-hour ambulatory BP monitoring. A prospective follow-up study was performed to evaluate the occurrence of neurodegenerative disorders in the iRBD cohort.

RESULTS

In the iRBD group, night-time systolic BP (SBP) was higher (124.0±20.0, p=.026), nocturnal BP decrease lower (4.0±8.7% for SBP and 8.7±8.0% for DBP, p=.001), and non-dipping status more frequent (71.4% for systolic and 52.4% for diastolic BP; p=.001 and p=.01 respectively) than in the HCs. Reverse dipping of SBP was found in 23.8% (p=.048) of the iRBD subjects. Non-dipping status was not associated with differences in gender, age, disease duration, age at disease onset, UPDRS score, presence of antihypertensive therapy or polysomnographic measures. Patients with PD showed daytime and night-time BP profiles comparable to those observed in iRBD. A sub-group analysis considering only the subjects without antihypertensive therapy (12 iRBD, 12 PD) showed results superimposable on those of the whole iRBD and PD groups.Longitudinal follow up (mean 5.1±1.9 years) showed no differences in BP profile at baseline between converters (n=6) and non-converters.

CONCLUSIONS

24-hour BP control was impaired in iRBD. This impairment, similar to patterns observed in de novo PD, consisted of reduced amplitude of nocturnal dipping and increased frequency of non-dipping status. These findings could have implications for cardiovascular morbidity and mortality in iRBD.

Unexpected (123I)FP-CIT SPECT findings: SWIDD, SWEDD and all DAT

Although the diagnosis of Parkinson's disease (PD) is essentially clinical, the implementation of imaging techniques can improve diagnostic accuracy. While some techniques (e.g. magnetic resonance imaging-MRI, computerized tomography-CT) are used to exclude secondary syndromes, presynaptic dopaminergic imaging including imaging of dopamine transporter (DAT)-can help the Neurologist in the differential diagnosis between neurodegenerative parkinsonian syndromes and parkinsonism without dopamine deficiency. DAT imaging can be useful in cases in which the clinical picture is not univocal, as in case of overlapping clinical features in patients with early disease, atypical syndromes or unsatisfying response to therapy. Currently, (¹²³I)FP-CIT ([123I]N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl)nortropane) (trade name DaTSCAN) is the only agent approved by international regulatory agencies for this purpose. With the increasing use of this technique, some unexpected findings have been reported, including patients clinically diagnosed with PD with a normal SPECT scan [e.g. Scans Without Evidence of Dopaminergic Deficit (SWEDD)]; PD patients with a greater dopaminergic deficit in the striatum ipsilateral to the clinically more affected side [e.g. Scans With Ipsilateral Dopaminergic Deficit (SWIDD)]; as well as some artifacts. Moreover, the neurologist must remember that structural lesions and administration of some drugs might alter the result of DAT imaging. Unexpected findings, artifacts, and misinterpretation of imaging findings can lead to an erroneous diagnosis and inappropriate therapy, neglect of other medical conditions that might explain the clinical picture, and undermine the selection phase in clinical trials. The aim of the present review is to bring clarity on these controversial (and sometimes erroneous) results, in order to inform of these possibilities the clinicians requesting a DaTSCAN in clinical practice.

The Association of Orthostatic Hypotension With Ambulatory Blood Pressure Phenotypes in SPRINT

BACKGROUND

Clinic blood pressure (BP) when measured in the seated position, can miss meaningful BP phenotypes, including low ambulatory BP (white coat effects [WCE]) or high supine BP (nocturnal non-dipping). Orthostatic hypotension (OH) measured using both seated (or supine) and standing BP, could identify phenotypes poorly captured by seated clinic BP alone.

METHODS

We examined the association of OH with WCE and night-to-daytime systolic BP (SBP) in a subpopulation of SPRINT, a randomized trial testing the effects of intensive or standard (<120 vs. <140 mm Hg) SBP treatment strategies in adults at increased risk of cardiovascular disease. OH was assessed during follow-up (6, 12, and 24 months) and defined as a decrease in mean seated SBP ≥20 or diastolic BP ≥10 mm Hg after 1 min of standing. WCE, based on 24-hour ambulatory BP monitoring performed at 27 months, was defined as the difference between 27-month seated clinic and daytime ambulatory BP ≥20/≥10 mm Hg. Reverse dipping was defined as a ratio of night-to-daytime SBP >1.

RESULTS

Of 897 adults (mean age 71.5±9.5 years, 29% female, 28% black), 128 had OH at least once. Among those with OH, 15% had WCE (vs. 7% without OH). Moreover, 25% of those with OH demonstrated a non-dipping pattern (vs. 14% without OH). OH was positively associated with both WCE (OR=2.24; 95%CI: 1.28, 4.27) and reverse dipping (OR=2.29; 95% CI: 1.31, 3.99).

CONCLUSIONS

The identification of OH in clinic was associated with two BP phenotypes often missed with traditional seated BP assessments. Further studies on mechanisms of these relationships are needed.

CLINICAL TRIALS REGISTRATION

Trial Number NCT03569020.

Blood Pressure Patterns in Patients with Parkinson's Disease: A Systematic Review

(1) Background: Cardiovascular autonomic dysfunction is a non-motor feature in Parkinson’s disease with negative impact on functionality and life expectancy, prompting early detection and proper management. We aimed to describe the blood pressure patterns reported in patients with Parkinson’s disease, as measured by 24-h ambulatory blood pressure monitoring. (2) Methods: We conducted a systematic search on the PubMed database. Studies enrolling patients with Parkinson’s disease undergoing 24-h ambulatory blood pressure monitoring were included. Data regarding study population, Parkinson’s disease course, vasoactive drugs, blood pressure profiles, and measurements were recorded. (3) Results: The search identified 172 studies. Forty studies eventually fulfilled the inclusion criteria, with 3090 patients enrolled. Abnormal blood pressure profiles were commonly encountered: high blood pressure in 38.13% of patients (938/2460), orthostatic hypotension in 38.68% (941/2433), supine hypertension in 27.76% (445/1603) and nocturnal hypertension in 38.91% (737/1894). Dipping status was also altered often, 40.46% of patients (477/1179) being reverse dippers and 35.67% (310/869) reduced dippers. All these patterns were correlated with negative clinical and imaging outcomes. (4) Conclusion: Patients with Parkinson’s disease have significantly altered blood pressure patterns that carry a negative prognosis. Ambulatory blood pressure monitoring should be validated as a biomarker of PD-associated cardiovascular dysautonomia and a tool for assisting therapeutic interventions.

Differences in correlations of depression and anhedonia with cardiovascular sympathetic functions during a head-up tilt test in drug-naïve Parkinson's disease patients

BACKGROUND

Depression is a symptom of Parkinson's disease (PD) and may be correlated with cardiovascular sympathetic function. Anhedonia is an element of depression, but these symptoms can emerge independently in PD. A correlation of anhedonia with cardiovascular sympathetic function has rarely been examined.

OBJECTIVE

To compare correlations of depression and anhedonia with cardiovascular sympathetic function in drug-naive PD patients.

METHODS

Assessments of depression (Self-rating Depression Scale; SDS), anhedonia (Snaith-Hamilton Pleasure Scale; SHAPS), myocardial ¹²³I-MIBG (¹²³I-meta-iodobenzylguanidine) scintigraphy (heart to mediastinum (H/M) ratios in early and delayed images), and head-up tilt test (HUT) up to 60° for 10 min were performed in 45 drug-naïve PD patients. During the HUT, blood pressure was measured every minute and the maximum decrease in systolic blood pressure (SBP) was determined. Plasma noradrenaline (NA) and arginine vasopressin (AVP) levels were examined at baseline and 10 min after tilt, with subsequent calculation of increases in plasma NA and AVP levels in this 10 min. Correlation coefficients were calculated among these assessment parameters.

RESULTS

SDS significantly correlated with % maximum decrease in SBP (r = 0.344, p = 0.02), but not with H/M ratios in both images and increases in plasma NA and AVP levels. SHAPS did not correlate with the change in SBP, H/M ratios in both images, or plasma NA and AVP levels.

CONCLUSION

Depression was correlated with the % maximum decrease in SBP during a 10-min HUT, but anhedonia did not show this relationship. This suggests that depression and anhedonia may have different pathophysiological backgrounds in drug-naïve PD patients.

Autonomic Testing Profiles in Scans without Evidence of Dopaminergic Deficit (SWEDD)

BACKGROUND

Scans without evidence of dopaminergic deficit (SWEDDS) on 123I-FP-CIT SPECT (DAT) can occur in patients with clinical evidence of Parkinsonism. In this patient population, autonomic function testing may elucidate the underlying clinical disorder.

OBJECTIVE

To evaluate SWEDD patients undergoing autonomic testing and determine the severity and pattern of autonomic dysfunction.

METHODS

All patients with a diagnosis of SWEDD and formal autonomic function testing at Mayo Clinic, MN were retrospectively reviewed. Autonomic failure was quantified using composite autonomic severity score (CASS). The Modified Hoehn and Yahr score (HYS) determined Parkinsonism severity.

RESULTS

Of 1,874 patients with DAT imaging at Mayo Clinic, 13 met diagnostic criteria of SWEDD. The median age of symptom onset was 56.0 (IQR 40.5-75.5). Autonomic dysfunction was present in 12/13 on ARS and/or TST. The median CASS was 2.50 (IQR 1.00-3.00). Distal anhidrosis was most common (7/13) while 3/13 had widespread anhidrosis on TST and/or QSART testing. Patients with a distal pattern of anhidrosis had a median score of 3.0 (IQR 2.38-4.25) on the HYS versus 2.0 (IQR 1.00-2.00) for those with a diffuse pattern (p = 0.048). Patients with more advanced Parkinsonism were more likely to respond to L-Dopa, with higher HYS in the dopa-responsive versus non-Dopa-responsive (p = 0.026). No correlation existed between severity of Parkinsonism, and CASS (p = 0.39).

CONCLUSION

Autonomic function testing may detect autonomic dysfunction in most patients with SWEDD. The pattern of dysfunction is suggestive of the degree of clinical Parkinsonism, and autonomic testing may predict whether patients with SWEDD respond to L-Dopa.

Nonmotor Symptoms in Essential Tremor and Other Tremor Disorders

Tremor, like dystonia, is a term used at the phenomenological, syndromic, and aetiopathological level. Parkinsonian, essential, and dystonic tremor are the three most common tremor diagnoses encountered in clinical practice. Investigation of nonmotor symptoms in essential tremor and dystonic tremor syndromes is significantly hampered by the lack of clear clinical diagnostic criteria for these groups at a syndromic level, and the absence of biomarkers which allow definitive diagnosis at an aetiopathological level. Much work is needed in clarifying the motor features of these disorders in order to allow delineation of the nonmotor features of the most common tremor syndromes. With this limitation in mind, this chapter reviews what is known about nonmotor symptoms in these two tremor types. The final sections deal with nonmotor symptoms observed in patients with lesional tremor, thankfully a much more clearly defined albeit less common group of patients.