Biomedical subjects

Robert D Fealey

Publications and source records attributed to Robert D Fealey.

11 recordsLinked to original sources

PubMed2006

Thermoregulatory sweat testing in patients with erythromelalgia.

OBJECTIVES: To examine the results of thermoregulatory sweat testing in patients with erythromelalgia and to compare them with the results of other neurophysiologic tests of small-fiber nerve function. DESIGN: Retrospective study. SETTING: Tertiary referral center. PATIENTS: Thirty-two consecutive patients with erythromelalgia who had thermoregulatory sweat testing in addition to vascular and nerve testing. INTERVENTION: The following information was abstracted for each patient: demographics, clinical presentation, and results of thermoregulatory sweat testing, vascular (noninvasive) testing, and nerve testing (electromyography and autonomic reflex screen, including quantitative sudomotor axon reflex test). MAIN OUTCOME MEASURES: Results of thermoregulatory sweat testing to evaluate small-fiber neuropathy, compared with other tools used to estimate small-fiber neuropathy. RESULTS: Thermoregulatory sweat testing results were abnormal in 28 (88%) of 32 patients, and quantitative sudomotor axon reflex test results were abnormal in 22 patients (69%). Abnormalities noted on thermoregulatory sweat testing varied from local hypohidrosis or anhidrosis to global anhidrosis. Global or almost-global anhidrosis was present in 8 patients (25%); in 19 patients (59%) the anhidrosis was distal, and 1 other patient (3%) had a less specific pattern of anhidrosis (multifocal or regional). The area of anhidrosis generally corresponded to the area that was symptomatic of the erythromelalgia. CONCLUSIONS: Small-fiber neuropathy is prevalent in most patients with erythromelalgia. Thermoregulatory sweat testing is a sensitive and useful marker of small-fiber neuropathy in these patients.

Adolescent↗

PubMed2006

Detection of small-fiber neuropathy by sudomotor testing.

The symptoms of burning sensation affecting the feet, thought to be due to a distal small-fiber neuropathy (DSFN) affecting somatic unmyelinated fibers, are usually accompanied by vasomotor or sudomotor changes suggestive of involvement of autonomic fibers. We therefore examined the relationship between pattern of anhidrosis and DSFN and its etiology, comparing patients with "pure" DSFN (with normal nerve conduction) to those with clinical DSFN (minor conduction abnormalities). We reviewed 125 cases with a clinical phenotype of DSFN. These patients had distal burning discomfort, variable sensory deficits, and intact motor function. All had undergone assessment with thermoregulatory sweat test (TST), autonomic reflex screen (ARS), and nerve conduction studies and electromyography (NCS/EMG). TST showed a distal pattern of anhidrosis in 74%. The quantitative sudomotor axon reflex test (QSART) was abnormal in 74%, with 80% of those having a length-dependent pattern of anhidrosis/hypohidrosis. In total, 93% of patients had a distal pattern of abnormality on QSART or TST. The Composite Autonomic Severity Score (CASS) was used to quantify the severity and distribution of autonomic deficits: 98% had CASS abnormality (sudomotor, 98%; adrenergic, 43%; cardiovagal, 35%). EMG was normal or showed unrelated abnormalities in 75%. The most common etiologies of DSFN were idiopathic (73%), presumed hereditary (18%), and diabetes (10%). Sudomotor examination is thus a highly sensitive detection tool in DSFN. Autonomic involvement is mainly distal, and additionally may involve adrenergic and the long cardiovagal fibers.

Adult↗

PubMed2005

Delayed threshold for active cutaneous vasodilation in patients with Type 2 diabetes mellitus.

Epidemiological evidence suggests decreased heat tolerance in patients with Type 2 diabetes mellitus (T2DM), but it is not known whether the mechanisms involved in thermoregulatory control of skin blood flow are altered in these patients. We tested the hypothesis that individuals with T2DM have a delayed internal temperature threshold for active cutaneous vasodilation during whole body heating compared with healthy control subjects. We measured skin blood flow using laser-Doppler flowmetry (LDF), internal temperature (T or) via sublingual thermocouple, and mean arterial pressure via Finometer at baseline and during whole body heating in 9 T2DM patients and 10 control subjects of similar age, height, and weight. At one LDF site, sympathetic noradrenergic neurotransmission was blocked by local pretreatment with bretylium tosylate (BT) to isolate the cutaneous active vasodilator system. Whole body heating was conducted using a water-perfused suit. There were no differences in preheating T(or) between groups (P > 0.10). Patients with T2DM exhibited an increased internal temperature threshold for the onset of vasodilation at both untreated and BT-treated sites. At BT-treated sites, T or thresholds were 36.28 +/- 0.07 degrees C in controls and 36.55 +/- 0.05 degrees C in T2DM patients (P < 0.05), indicating delayed onset of active vasodilation in patients. Sensitivity of vasodilation was variable in both groups, with no consistent difference between groups (P > 0.05). We conclude that altered control of active cutaneous vasodilation may contribute to impaired thermoregulation in patients with T2DM.

Adrenergic Antagonists↗

PubMed2005

Neurologic spectrum of chronic liver failure and basal ganglia T1 hyperintensity on magnetic resonance imaging: probable manganese neurotoxicity.

BACKGROUND: An atypical form of parkinsonism has been described in patients with chronic liver disease, associated with increased T1 signal in the basal ganglia on magnetic resonance imaging. The magnetic resonance imaging signal changes are characteristic of manganese accumulation, which has been neuropathologically confirmed. Manganese neurotoxicity may result in additional neurologic findings besides parkinsonism. OBJECTIVE: To fully characterize patients with chronic central nervous system symptoms and chronic liver failure associated with basal ganglia T1 hyperintensity. DESIGN: Prospective and retrospective case study. SETTING: Mayo Clinic, Rochester, Minn. PARTICIPANTS: Eight patients referred for neurologic evaluation and studied prospectively, and 7 additional retrospectively identified patients who had been examined by Mayo Clinic neurologists. MAIN OUTCOME MEASURES: Neurologic syndromes identified. RESULTS: Three syndromes were recognized in these 15 patients with liver failure and basal ganglia T1 hyperintensity on magnetic resonance imaging: (1) isolated parkinsonism, (2) gait ataxia plus other neurologic findings (ataxia-plus), and (3) cognitive impairment with psychiatric features. All but 1 patient had elevated blood manganese levels. Ammonia levels were normal in most, and the neurologic syndromes did not appear to reflect the well-known toxic-metabolic encephalopathy of liver disease. CONCLUSIONS: Chronic liver failure may result in heterogeneous neurologic syndromes that cut across a variety of liver diseases. We selected cases on the basis of evidence of brain manganese accumulation, and this may be a crucial component of these syndromes. Further studies are necessary to explore this issue.

Adult↗

PubMed2005

A comparison of peripheral skin blood flow and temperature during endoscopic thoracic sympathotomy.

The assessment of sympathetic denervation to the upper extremities during surgery for hyperhidrosis is essential in predicting postoperative outcome, particularly for endoscopic thoracic chain sympathotomy, a recently described, minimally destructive technique that minimizes postoperative compensatory hyperhidrosis. To test the hypothesis that skin blood flow (SkBF; laser Doppler flowmetry) provides a faster and more reliable indication of denervation than temperature (temp), we prospectively compared palmar SkBF and fingertip temp in 10 patients undergoing endoscopic thoracic chain sympathotomy for essential hyperhidrosis. From baseline to peak values, palmar SkBF (mean +/- SEM) increased 273.3 +/- 24.7 arbitrary units and 252.4 +/- 30.1 arbitrary units, whereas temp increased 0.9 degrees C +/- 0.3 degrees C and 1.5 degrees C +/- 0.6 degrees C on the right and left, respectively. Upon effective sympathotomy of the right thoracic chain, the time to peak SkBF was 43 +/- 13 s, whereas the time to peak temp was 277 +/- 53 s (P <0.001). On the left, the time to peak SkBF was 81 +/- 14 s, and time to peak temp was 305 +/- 34 s (P <0.001). All patients considered the sympathotomy successful. We conclude that laser Doppler SkBF is superior to temp in temporal resolution for assessment of denervation during sympathotomy and that it provides a superior qualitative and quantitative adjunct to monitoring denervation.

Adolescent↗

PubMed2005

Hyperhidrosis: evolving therapies for a well-established phenomenon.

The socially embarrassing disorder of excessive sweating, or hyperhidrosis, and its treatment options are gaining widespread attention. In order of frequency, palmar-plantar, palmar-axillary, Isolated axillary, and cranlofacial hyperhidrosis are distinct disorders of sudomotor regulation. A common link among these disorders is an excessive, nonthermoregulatory sweat response often to emotional stimuli in body regions influenced by the anterior cingulate cortex as opposed to the thermoregulatory sweat response regulated by the preoptic-anterior hypothalamus. Diagnosis of these mechanistically ambiguous disorders is primarily from patient history and physical examination, whereas results of laboratory studies performed with indicator powder reveal the distribution and severity of resting hyperhidrosis and document the integrity of thermoregulatory sweating. Treatment options lie on a continuum based on the severity of hyperhidrosis and the risks and benefits of therapy. In general, therapy begins with antiperspirants or anticholinergics. Iontophoresis is available for palmar-plantar and axillary hyperhidrosis. Botulinum toxin type A or local excision/curettage is effective for isolated axillary hyperhidrosis not responsive to topical application of aluminum chloride. Endoscopic thoracic sympathectomy may be used for severe cases of palmar-plantar and palmar-axillary hyperhidrosis. No sole therapy of choice has emerged for craniofacial sweating. The long-term sequelae of hyperhidrosis and its treatment also are discussed.

Botulinum Toxins, Type A↗

PubMed2003

The spectrum of autoimmune autonomic neuropathies.

We analyzed the clinical characteristics of 18 patients (13 female, 5 male) who had autoimmune autonomic neuropathy (AAN) and ganglionic acetylcholine receptor (AChR) autoantibodies. Mean age was 61.4 years (standard deviation, 12.0 years). Ten patients had subacute symptom onset, six with an antecedent event. Eight patients had chronic AAN, characterized by insidious symptom onset, without antecedent event, and gradual progression. A majority of patients with high antibody values (>1.00 nmol/L) had a combination of sicca complex (marked dry eyes and dry mouth), abnormal pupillary light response, upper gastrointestinal symptoms, and neurogenic bladder. Chronic AAN segregated into two subgroups. One subgroup (N = 4) had low antibody titer (0.09 +/- 0.01 nmol/L) and a paucity of cholinergic symptoms. It was indistinguishable from pure autonomic failure. The other subgroup (N = 4) had high antibody titer (11.6 +/- 2.08 nmol/L), sicca complex, abnormal pupils, and neurogenic bladder; three had severe upper gastrointestinal dysfunction. Higher antibody titers correlated with greater autonomic dysfunction and more frequent cholinergic dysautonomia. These observations expand the clinical spectrum of AAN to include chronic cases, some being indistinguishable from pure autonomic failure, and support the concept that ganglionic AChR antibodies are important diagnostically and pathophysiologically in acquired dysautonomia.

Adolescent↗

PubMed2003

Sympathotomy instead of sympathectomy for palmar hyperhidrosis: minimizing postoperative compensatory hyperhidrosis.

OBJECTIVE: To determine whether anatomical modification of sympathectomy diminishes severe postoperative compensatory hyperhidrosis. PATIENTS AND METHODS: From January 1, 2000, to June 1, 2001, we prospectively studied 10 consecutive patients with primary palmar hyperhidrosis, aged 14 to 42 years. Medical therapy had failed in all patients. A preoperative and postoperative evaluation and thermoregulatory sweat testing were conducted in all patients. All patients underwent sympathotomy (bilateral simple disconnection) of the second thoracic ganglion input into the brachial plexus, and no sympathetic ganglia were violated. RESULTS: In the 10 patients, all 20 upper extremities improved postoperatively: 11 (55%) had near-complete cessation of palmar sweating, 8 (40%) had marked reduction in sweating, and 1 (5%) had delayed onset but full sweating at the end of the thermoregulatory sweat test. No intraoperative complications of hemopneumothorax or Horner syndrome occurred. Importantly, there were no moderate or severe postoperative hyperhidrosis complications. CONCLUSION: Sympathotomy to disconnect T2 ganglion input into the brachial plexus produces excellent results in the treatment of primary palmar hyperhidrosis and may lower the severity of postoperative compensatory hyperhidrosis complications. Long-term durability of the procedure requires further follow-up.

Adolescent↗

PubMed2002

Effects of chronic sympathectomy on locally mediated cutaneous vasodilation in humans.

In human skin, the vasodilator response to local heating includes a sensory nerve-dependent peak followed by a nadir and then a slower, nitric oxide-mediated, endothelium-dependent vasodilation. To investigate whether chronic sympathectomy diminishes this endothelium-dependent vasodilation, we studied individuals who had previously undergone surgical T(2) sympathectomy (n = 9) and a group of healthy controls (n = 8). We assessed the cutaneous vascular response (laser-Doppler) to 30 min of local warming to 42.5 degrees C on the ventral forearm (no sympathetic innervation) and the lower legs (sympathetic nerves intact). Lower body negative pressure (LBNP) was measured to confirm sympathetic denervation. During local warming in sympathectomized individuals, vascular conductance reached an initial peak at both sites [achieving 1.73 +/- 0.22 laser-Doppler units (LDU)/mmHg in the forearm and 1.92 +/- 0.21 LDU/mmHg in the leg]. It then decreased to a nadir in the innervated leg [to 1.77 +/- 0.23 LDU/mmHg (P < 0.05)] but not in the sympathectomized arm (1.69 +/- 0.21 LDU/mmHg; P > 0.10). The maximal vasodilation seen during the slower phase was not different between limbs or between groups. Furthermore, LBNP caused a 44% reduction in forearm vascular conductance (FVC) in control subjects, but FVC did not decrease significantly in sympathectomized individuals, confirming sympathetic denervation. These data indicate that endothelial function in human skin is largely preserved after sympathectomy. The altered pattern of the response suggests that the nitric oxide-dependent portion may be accelerated in sympathectomized limbs.

Adult↗

PubMed2002

Effects of chronic sympathectomy on vascular function in the human forearm.

To determine whether endothelial function is altered by chronic surgical sympathectomy, we infused ACh, isoproterenol, nitroprusside (NTP), and the nitric oxide synthase inhibitor NG-mono-methyl-L-arginine (L-NMMA) into the brachial arteries of nine patients 5-64 mo after thoracic sympathectomy for hyperhidrosis. Age- and gender-matched controls were also studied. Forearm blood flow (FBF) was measured by venous occlusion plethysmography. Lower body negative pressure was used to assess reflex vasoconstrictor responses. Tyramine, which acts locally and causes norepinephrine release from sympathetic nerves, was also administered via the brachial artery. FBF at rest was 2.5 +/- 0.4 ml x dl-1 x min-1 in the patients and 2.5 +/- 0.3 ml x dl-1 x min-1 in the controls (P = 0.95). The normal vasoconstrictor responses to lower body negative pressure were abolished in the patients. By contrast, tyramine produced dose-dependent vasoconstriction in the patients that was identical to that of controls. The dose-response curves to ACh were similar in patients and controls, with maximum values of 19.3 +/- 4.4 vs. 25.5 +/- 2.8 ml x dl-1 x min-1, respectively. L-NMMA reduced baseline FBF similarly and reduced the maximal FBF response to ACh in both groups (patients 8.9 +/- 3.5 vs. controls 9.7 +/- 2.5 ml x dl-1 x min-1). The vasodilation to isoproterenol was similar and blunted to the same extent in both groups by L-NMMA. The responses to NTP in patients and controls were similar and not affected by L-NMMA. We conclude that, in humans, chronic surgical sympathectomy does not cause major disruptions in vascular function in the forearm. The normal vasoconstrictor responses to tyramine indicate that there were viable sympathetic nerves in the forearm that were not engaged by LBNP.

Adult↗

PubMedDate not supplied

Neurophysiologic studies in Morvan syndrome.

This study was conducted to clarify the clinical and neurophysiologic characteristics of patients with Morvan syndrome, and to compare and contrast this syndrome with other forms of autoimmune encephalitis. A retrospective chart review of the clinical features and neurophysiologic studies of two cases of Morvan syndrome seen at the Mayo Clinic was performed. Neurophysiologic studies included polysomnography, comprehensive autonomic testing, MRI, positron emission tomography, EEG, and single-photon emission computed tomography. In two cases of Morvan syndrome, the clinical features, electrophysiologic findings, and immunologic studies (high levels of voltage-gated potassium channel antibodies) were consistent with previously reported findings. Several novel observations were made. Autonomic testing demonstrated peripheral autonomic neuropathy in addition to autonomic hyperactivity. Polysomnography showed complete absence of sleep. Neuroimaging study findings were largely normal. Morvan syndrome is an autoimmune disorder affecting both the peripheral and central nervous system. Neurophysiologic studies demonstrate hyperexcitability of peripheral nerves, autonomic dysfunction, and severe insomnia. The absence of abnormalities on imaging studies suggests that central nervous system symptoms are related to functional rather than structural disruption of neural networks.

Adult↗