An Evaluation of Minimal F-wave Sensitivity in Carpal Tunnel Syndrome.

Background and objective Several recent studies have explored whether F-waves can be a sensitive and useful tool for diagnosing carpal tunnel syndrome (CTS). In light of this, we aimed to measure the minimal F-wave latencies in patients with mild, moderate, and severe electrophysiologically diagnosed carpal CTS, as well as individuals without CTS, to determine at which point this parameter becomes sensitive to the syndrome. Materials and methods Nerve conduction studies were carried out in a room where a temperature of 22-24 °C was maintained. The F-waves of the median nerve in all patients and individuals in the control group were recorded. The F-wave with the highest velocity (minimal F) was categorized into the normal, mild, moderate, and severe groups for statistical analysis. All measurements were performed by the same electrophysiology-experienced neurologist. Results Post-hoc analysis demonstrated that the F latency values of the moderate and severe CTS groups were significantly higher than those of the control group (p<0.001 for all comparisons). Furthermore, the F latency values of the severe CTS group were significantly higher than those of the moderate group (p=0.026). Conclusions Based on our findings, minimal F-wave latency is a reliable indicator of moderate to severe CTS. This sensitivity significantly increases in severe cases while disappearing in the presence of mild CTS.

Effects of the Cold Pressor Test on Popliteal Vein Diameter, Flow Velocity, and Blood Flow in the Lower Limb in 60 Healthy Individuals.

BACKGROUND In various situations such as pain, exposure to hot or cold, and mental stress, where physiological stress occurs, the increased excitatory response in the sympathetic efferent neurons leads to an increased return of blood flow from the peripheral veins to the right atrium. The cold pressor test (CPT) is based on the effects of a cold stimulus that activates afferent sensory pathways to trigger a sympathetic response, resulting in an increase in blood pressure. This study aimed to evaluate the effects of the cold pressor test on popliteal vein diameter, flow velocity, and blood flow in the lower limbs in 60 healthy individuals. MATERIAL AND METHODS We included 30 men and 30 women age 18-40 years. Baseline vein diameter, flow velocity, and blood flow of the left popliteal vein were measured by Doppler ultrasound, then the left hand was immersed in a bucket of cold water. After immersing the hand in cold water for 1 minute (CPT-1), 3 measurements of vein diameter, flow velocity, and blood flow were taken again, and their averages were calculated. RESULTS In the study, data obtained from the individuals were statistically analyzed. At CPT-1, venous diameter and flow values showed significant increase compared to baseline (P=0.001, P<0.001, respectively). CONCLUSIONS In healthy volunteers, CPT increases venous flow in the popliteal veins. However, our study did not provide evidence for the hypothesis that the increase in venous return is due to venoconstriction mechanisms.

Diabetic neuropathy results in vasomotor dysfunction of medium sized peripheral arteries.

BACKGROUND: The effect of the sympathetic nervous system on peripheral arteries causes vasoconstriction when smooth muscle cells in the walls of blood vessels contract, which leads to narrowing of arteries and reduction of the blood flow. AIM: To compare sympathetic vasomotor activation of the brachial arteries in healthy subjects and patients with painful diabetic neuropathy; and therefore, to assess whether there is significant vasomotor dysfunction of medium sized arteries in diabetic neuropathy. METHODS: The study included 41 diabetic neuropathy patients and 41 healthy controls. Baseline diameter and flow rate of the brachial arteries were measured. Then, using a bipolar stimulus electrode, a 10 mA, 1 Hz electrical stimulus was administered to the median nerve at the wrist level for 5 s. The brachial artery diameter and blood flow rate were re-measured after stimulation. RESULTS: In the control group, the median flow rate was 70.0 mL/min prior to stimulation and 35.0 mL/min after stimulation, with a statistically significant decrease (P < 0.001), which is consistent with sympathetic nervous system functioning (vasoconstriction). In the diabetic neuropathy group, median flow rate before the stimulation was 35.0 mL/min. After stimulation, the median flow rate was 77.0 mL/min; thus, no significant decrease in the flow rate was detected. In the control group, the median brachial artery diameter, which was 3.6 mm prior to stimulation, decreased to 3.4 mm after stimulation, and this decrease was also statistically significant (P = 0.046). In the diabetic neuropathy group, the median brachial artery diameter increased from 3.4 mm to 3.6 mm following nerve stimulation. Once again, no narrowing was observed. CONCLUSION: Our research suggests that diabetic neuropathy results in significant vasomotor dysfunction of medium sized peripheral arteries. Physiological vasoconstriction in response to sympathetic activation is impaired in diabetic neuropathy.

Can the change of vasomotor activity in irritable bowel syndrome patients be detected via color Doppler ultrasound?

BACKGROUND: Irritable bowel syndrome (IBS) is one of the most frequently referred conditions to the gastrointestinal outpatient clinic. The pathophysiology of IBS has not been determined with certainty. Visceral hypersensitivity is indicated as one of the pathophysiologies. The sympathetic nervous system is primarily in charge of controlling the arteries, and its effect is vasospasm in the medium and large arteries, resulting in decreased blood flow. AIM: To demonstrate, using Doppler evaluation of the brachial artery, that sympathetic activity impairs vasomotor performance due to autonomic neuropathy, which we believe is associated with IBS. METHODS: There were 58 participants in the study. The control group consisted of 29 healthy patients, while the remaining 29 patients had been diagnosed with IBS. Patients who met the Rome IV criteria and had IBS were included in the study. People with known polyneuropathy or non-IBS chronic conditions that can progress were excluded from the trial, as were those with essential hypertension, diabetes mellitus, cardiovascular disease, or peripheral arterial disease, and patients diagnosed with anxiety or depression. Those with moderate to severe carpal tunnel syndrome or a median nerve lesion due to trauma were also excluded from the trial. A Doppler probe was used to measure the baseline diameter and flow rates of the brachial artery from 2 cm superior to the antecubital fossa. The Doppler probe remained stationary throughout the experiment, allowing for continuous measurements. Then, to activate the sympathetic fibers, an electrical stimulus for 5 s with an intensity of 10 mA and a frequency of 1 Hz was applied to the median nerve at the wrist level via the bipolar stimulus electrode. The artery diameter and flow rates were measured again immediately following the fifth stimulus. RESULTS: In healthy persons with no history of chronic illness, there was a statistically significant decrease in flow rate after stimulation (P < 0.001). In addition, stimulation resulted in a statistically significant reduction in the diameter of the brachial artery (P < 0.001). Patients diagnosed with IBS had statistically significant vasodilation and an increase in flow rate. CONCLUSION: Sympathetic stimulation causes a reduction in vascular diameter and blood flow, whereas it has the reverse effect on IBS patients. In investigating the involvement of autonomic neuropathy in the development of IBS, significant changes in brachial artery Doppler parameters were observed before and after stimulation of the median nerve with low-current sensory stimulation. This method is thought to be more user-friendly and comfortable than other methods described in the literature.

Evaluation of Sympathetic Vasomotor Activity of the Brachial Arteries Using Doppler Ultrasound.

BACKGROUND The sympathetic nervous system is principally accountable for peripheral artery regulation, and its effect is that vasospasm occurs in the medium and large arteries of the extremities, resulting in decreased flow of blood. Because of this information of how the body works, our goal is to create a noninvasive and repeatable self-test model that uses Doppler ultrasound examination. MATERIAL AND METHODS The study was conducted on 31 healthy and active participants who volunteered for the study. Written informed consent was obtained from all participants. The baseline diameter and flow rates of the brachial artery from 2 cm superior to the antecubital fossa were determined using a Doppler probe, which remained stationary throughout the experiment, allowing for continuous measurements. Then, to activate the sympathetic fibers, an electrical stimulus was applied for 5 s with an intensity of 10 mA and frequency of 1 Hz at the level of the median nerve at the wrist via the bipolar stimulation electrode. Immediately following the sixth stimulation, the artery diameter and flow rates were assessed again. RESULTS Following the stimulation, a statistically significant decrease in flow rate was observed (P<0.001). Moreover, stimulation resulted in a statistically significant reduction in the diameter of the brachial artery (P<0.001). CONCLUSIONS Our research suggests that Doppler ultrasonography can be routinely used to detect the normal and abnormal functioning of the peripheral sympathetic nervous system.

Median Nerves' Electrical Activation Reduces Ipsilateral Brachial Arteries' Blood Flow and Diameter.

Purpose: Our main objective in this study was to determine whether there is a difference between ipsilateral and contralateral brachial arteries' flow parameters in response to median nerves' electrical activation. Material and Methods: The study was conducted in healthy and active subjects. The arterial diameter and flow were measured using the probe from the brachial artery. Then, the median nerve was stimulated for 5 seconds via the bipolar stimulus electrode. Arterial diameter and flow were measured once more with the Doppler transducer, which kept going to monitor continuously just after the fifth stimulus. After a week, the same subjects are invited for the purpose of measuring the contralateral brachial arteries' vasomotor response to the same stimulus. Results: Before electrical stimulation, the median flow rate was 72.15 ml/min; after stimulation, the median flow rate was 39.20 ml/min. The drop in flow after stimulation was statistically significant (P < 0.001). While the median value of brachial artery vessel diameter before median nerve stimulation in the entire study group was 3.50 mm, the median value of vessel diameter after stimulation was 2.90 mm. After stimulation, the median nerve diameter narrowed statistically significantly (P < 0.001). As for the contralateral brachial in response to the right median nerves' activation, no significant flow or diameter change was found (P = 0.600, P = 0.495, respectively). Conclusion: We discovered that electrical stimulation of the median nerve caused significant changes in ipsilateral brachial artery blood flow and diameter in healthy volunteers. The same stimulation does not result in flow parameter changes in the contralateral brachial artery.

Language Disorders due to Posterior System Strokes - An Ignored Dysfunction.

The anterior system is primarily responsible for the clinical picture in a patient that presents with clinical aphasia. However, recent reports have shown that injuries to posterior structures, the cerebellum in particular, may have a role in language processing. Herein, we will look first at the linguistic role of the cerebellum in light of the literature, then of the thalamus and some described clinical syndromes, and finally, specific syndromes resulting from occipital lobe lesions, all of which are supported by the posterior vascular system. The human brain is such a complex organization that in addition to the thalamus and occipital cortex, we can see the involvement of the cerebellum in high cognitive functions. Posterior system strokes may lead to clinical findings of cognitive deficits, including neurolinguistic components. Determining these defects in stroke patients may precipitate changes in current management strategies.

A useful new coma scale in acute stroke patients: FOUR score.

Assessment of the severity of unconsciousness in patients with impaired consciousness, prediction of mortality and prognosis are currently the most studied subjects in intensive care. The aim of this study was to investigate the usefulness of the Full Outline of UnResponsiveness (FOUR) score in intensive care unit patients with stroke and the associations of FOUR score with the clinical outcome and with other coma scales (Glasgow [GCS] and Acute Physiology and Chronic Health Evaluation II). One hundred acute stroke patients (44 male, 56 female), who were followed in a neurology intensive care unit, were included in this prospective study. The mean age of the patients was 70.49 ± 12.42 years. Lesion types were determined as haemorrhagic in 30 and ischaemic in 70 patients. FOUR scores on the day of admission and the first, third and 10th days of patients who died within 15 days were lower when compared to scores of patients who survived (P=0.005, P=0.000, P=0.000 and P=0.000 respectively). Receiver operating characteristic curve analysis showed significant trending with both FOUR score and GCS for prognosis; the area under curve ranged from 0.675 (95% confidence interval 0.565 to 0.786) when measurements had been made on day 3 to 0.922 (95% confidence interval 0.867 to 0.977) and 0.981 (95% confidence interval 0.947 to 1.015) for day 10. We suggest that FOUR score is a useful scale for evaluation of acute stroke patients in the intensive care unit as a homogeneous group, with respect to the outcome estimation.