Juan Idiaquez

Autonomic and Cognitive dysfunction in Parkinson’s disease

ObjectiveTo investigate whether there is an association between autonomic failure and cognitive impairment in patients with idiopathic Parkinson’s disease (PD)Methods40 PD patients and 30 age matched controls were assessed for cognitive and behavioral manifestations using the Mini-Mental State Examination (MMSE), the Frontal Assessment Battery (FAB), the Blessed scale and Cornell scale for depression. The subjects were also assessed for orthostatic hypotension (OH), postprandial hypotension (PPH), heart rate responses to deep breathing (HRDB) and autonomic symptoms using the Scale for Outcomes in PD for autonomic symptoms (SCOPA AUT).ResultsThere was a correlation between the severity of motor symptoms and cognitive impairment in our PD patients. Eleven of the 40 PD patients fulfilled the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria of dementia. The presence of OH or PPH did not correlate with the severity of cognitive impairment in our PD cases. However, PD patients with dementia reported more cardiovascular symptoms than PD patients without dementia. There was no correlation between gastrointestinal or urologic symptoms and cognitive impairment in our PD cases.ConclusionThe results of this limited study indicate that despite the higher incidence of cardiovascular symptoms in PD patients with dementia than in those without dementia, there is no consistent association between OH or PPH and cognitive deficits in PD. The lack of correlation between OH, gastrointestinal and urinary symptoms with cognitive impairment suggests that cognitive and autonomic involvement progresses independently from each other and variably among PD patients.

Autonomic dysfunction in neurodegenerative dementias

Syncope associated to orthostatic hypotension (OH), urinary incontinence and constipation is common symptoms in demented patients, mainly in dementia with Lewy bodies (DLB) and in Parkinsons disease dementia (PDD). Alzheimers disease (AD) and fronto temporal lobar degeneration (FTLD) show less autonomic dysfunction. Urinary symptoms are a prominent component of normal pressure hydrocephalus (NPH). There are non invasive tests including standard cardiovascular tests, 123 I-metaiodobenzylguanide (MIBG) cardiac scintigraphy, urodynamic tests, gastrointestinal motility studies, sweating reflexes and pupillary responses that assess autonomic dysfunction in these patients. The study of autonomic symptoms and abnormal tests in patients with dementia is useful to prevent morbidity due falls, severe constipation and to avoid side effects of drugs that interfere with autonomic function.

Carotid body chemoreceptors, sympathetic neural activation, and cardiometabolic disease

AbstractThe carotid body (CB) is the main peripheral chemoreceptor that senses the arterial PO2, PCO2 and pH. In response to hypoxemia, hypercapnia and acidosis, carotid chemosensory discharge elicits reflex respiratory, autonomic and cardiovascular adjustments. The classical construct considers the CB as the main peripheral oxygen sensor, triggering reflex physiological responses to acute hypoxemia and facilitating the ventilatory acclimation to chronic hypoxemia at high altitude. However, a growing body of experimental evidence supports the novel concept that an abnormally enhanced CB chemosensory input to the brainstem contributes to overactivation of the sympathetic nervous system, and consequent pathology. Indeed, the CB has been implicated in several diseases associated with increases in central sympathetic outflow. These include hypertension, heart failure, sleep apnea, chronic obstructive pulmonary disease and metabolic syndrome. Indeed, ablation of the CB has been proposed for the treatment of severe and resistant hypertension in humans. In this review, we will analyze and discuss new evidence supporting an important role for the CB chemoreceptor in the progression of autonomic and cardiorespiratory alterations induced by heart failure, obstructive sleep apnea, chronic obstructive pulmonary disease and metabolic syndrome.

Association between neuropsychiatric and autonomic dysfunction in Alzheimer's disease

Abstract We sought to determine whether there was an association between specific neuropsychiatric deficits and autonomic dysfunction in patients with Alzheimers disease (AD). We studied 20 patients and 20 age-matched control subjects with neuropsychiatric tests (Blessed, Cornell depression and NPI scores) and autonomic tests (Deep breath (HRdb), 30:15 ratio and orthostatic hypotension (Bpoh)). The 30:15 ratio was consistently reduced in AD patients as compared to control subjects (1.05 ± 0.07 for patients and 1.18 ± 0.1 for controls, p 0.001). Whereas there were no significant differences in the HRdb and presence of Bpoh. In AD patients with an abnormal 30:15 ratio, there were significant abnormalities in the Blessed score and in the apathy, delusions and aberrant motor behavior items of the NPI. The other autonomic tests did not correlate with any neuropsychiatric score. The relationship between abnormal cortical function and impaired 30:15 ratio suggested that a lack of cortical modulation of autonomic circuits may underlie cardiovascular instability in these patients.

Neurobehavioral and autonomic alterations in adults with obstructive sleep apnea

OBJECTIVE Obstructive sleep apnea (OSA) is associated with sympathetic hyperactivity, excessive nocturnal sweating, sleepiness, and neurobehavioral cognitive alterations. However, it is not well known if cognitive consequences of OSA are independent from autonomic alterations. Thus, we assessed the association between polysomnographic, autonomic, and cognitive tests performance in OSA patients. METHODS Fifty eight OSA patients (53 male) were administered with questionnaires assessing demographic, Epworth, Beck Depression Inventory, Syndrom Kurz test (SKT), Trail Making part B (TMT-B), and Frontal Assessment Battery (FAB) tests. Spectral analysis of heart rate variability (HRV) and night sweating symptoms (NSwS) score were used to assess autonomic function. RESULTS Global cognitive function (SKT) was normal in mild-moderate (M-OSA) and severe (S-OSA) patients. In S-OSA patients AHI was correlated with TMT-B (r = 0.30 P < 0.05) and with FAB (r = -0.31 P < 0.05). Oxygen desaturation was correlated with TMT-B (r = -0.45 P = < 0.001) and FAB (r = 0.29 P = < 0.05). Sympathetic overactivity was correlated with oxygen desaturation: HRV (r = -0.39 P < 0.05) and NSwS score (r = -0.49 P < 0.01), but HRV and NSwS score were not correlated with TMT-B and FAB. CONCLUSION Frontal cognitive dysfunction and predominance of sympathetic drive occur in OSA patients. Abnormal frontal cognitive function and sympathetic hyperactivity were related to oxygen desaturation, but not between each other. We conclude that neurobehavioral changes and autonomic imbalance in OSA patients take place independently from each other, suggesting different pathophysiological pathways.

Postprandial hypotension in Alzheimer's disease

The degree of postprandial hypotension in patients with Alzheimers disease (AD) is not known. We therefore studied ten AD patients and 23 controls before and after a meal. Seven AD patients but only six controls showed a fall in blood pressure (BP) of 20 mmHg or more. Maximum BP fall in AD patients was observed between 20 and 120 min after food ingestion. This differed from the time course in other groups with primary chronic autonomic failure. Postural hypotension occurred in two controls, but not in AD patients. Abnormalities in cardiac vasomotor regulation, gut peptide liberation or both could be responsible for postprandial hypotension in AD.

Differences in postural hypotension and ankle jerks in the elderly from two contrasting socio-economic levels

Subjects in low socio-economic strata in underdeveloped countries are subjected to considerable adverse influences which may enhance age-related changes in the nervous system. We therefore assessed the presence of ankle jerks and the degree of postural hypotension in two groups, one from the upper socio-economic level (58 subjects) and the other from the lower socio-economic level (56 subjects). All subjects were over 65 years of age. Only 6% had bilateral loss of ankle jerks, with no difference between the groups. Postural hypotension of 30 mmHg or greater was more frequent in the upper socio-economic group, nine out of 58 versus two out of 56 in the lower group. We conclude that there is no relationship in the elderly between social deprivation and certain markers of neurological dysfunction, such as the absence of ankle jerks and postural hypotension. The reasons for a greater frequency of postural hypotension in the higher socioeconomic group are unclear.

Polineuropatía amiloidótica familiar tipo I

Familial amyloidotic polyneuropathy type I is an autosomal dominant inherited disorder characterized by progressive peripheral and autonomic neuropathy, associated with neural and systemic amyloid deposits. The abnormality usually lies in the transthyretin (TTR) gene. We report a 25 years old man with 18 months history of dysesthesias and pain in the toes, abnormal micturition and sexual dysfunction. Neurophysiologically studies disclosed a sensory-motor axonal polyneuropathy. Autonomic tests showed sympathetic and parasympathetic involvement. An electron micrograph of sural nerve revealed amyloid fibrils in the endoneurium. His mother died after a clinical history suggestive, in retrospect, of familial amyloidotic polyneuropathy type I. The clinical and genetic analysis of this cause of polyneuropathy are discussed.

Pure autonomic failure with cold induced sweating

Pure autonomic failure (PAF) is a progressive autonomic neurodegenerative disorder. Cold induced sweating occurred in syndromes with mutations in CRLF1 and CLCF1 genes and in a case of cervical dissection. A patient with PAF developed sweating induced by cool ambient temperatures. He had severe orthostatic hypotension, abnormal cardiovagal reflexes, and paradoxical sweating in the upper trunk at a room temperature of 18°C. Skin biopsy showed involvement of somatic epidermal unmyelinated nerve fibers. Quantitative sensory testing showed abnormal thresholds to all thermal modalities. Possible mechanisms include cold induced noradrenaline release in remaining autonomic innervation and a supersensitive sudomotor response.

Autonomic symptoms in hypertensive patients with post-acute minor ischemic stroke.

BACKGROUND Most studies regarding autonomic dysfunction in ischemic stroke are limited to heart rate and blood pressure changes during the acute phase. However, there are few data on quantitative assessment of autonomic symptoms. We sought to assess autonomic symptoms in hypertensive ischemic stroke patients. METHODS In 100 hypertensive patients (45 with symptomatic ischemic stroke (6 months after stroke onset) and 55 without stroke), we assessed autonomic symptoms using the Scale for Outcomes in Parkinson disease-Autonomic (SCOPA-AUT). RESULTS The age (mean ± standard deviation) for the stroke group was 66 ± 12 and 63 ± 15 for the without stroke group (P=0.8). Orthostatic hypotension occurred in 3.6% of the stroke group and 4.4% in the group without stroke. The total SCOPA-AUT score was higher in the stroke group compared with the group without stroke (P=0.001). Domain scores for gastrointestinal (P=0.001), urinary (P=0.005) and cardiovascular (P=0.001) were higher in the stroke group. No differences were found when comparing the total SCOPA-AUT scores for stroke subtypes (P=0.168) and for lateralization (P=0.6). SCOPA AUT scores were correlated with depression scores (P=0.001) but not with stroke severity (P=0.2). CONCLUSION Autonomic symptoms, especially, gastrointestinal, urinary and cardiovascular function, were significantly increased in hypertensive patients with minor ischemic stroke. Symptoms were associated with depression but not with the characteristic of the stroke.