Decreased cerebral vasomotor reactivity in patients with obstructive sleep apnea syndrome.

OBJECTIVE: In obstructive sleep apnea syndrome (OSAS), any of the activated neural, vascular, hemodynamic, metabolic, inflammatory, and thrombotic mechanisms may be related to increased cerebrovascular disease and risk of death; however, the possible pathophysiological process between obstructive sleep apnea syndrome and stroke has not been clearly explained. We hypothesize that alterations in vasomotor reactivity in patients may be responsible for their altered cerebral blood flow, and may contribute to the increased risk of ischemic stroke. METHODS: A total of 30 untreated patients with severe obstructive sleep apnea and 26 control subjects were included in the study. The mean blood flow velocity and breath holding index were measured in middle cerebral artery bilaterally in both patient and control groups by using transcranial Doppler ultrasound. We compared the values between two groups. RESULTS: The mean blood flow velocity and breath holding indexes were significantly decreased in the patient group when compared with the control group. There were no correlations between cerebral hemodynamic parameters and polysomnographic findings in patients. CONCLUSION: Our findings suggest that there was a deteriorated vasodilator response to hypercapnia in patients with OSAS. This deterioration may stem from chemoreceptors or endothelial damages that lead to vascular relaxation and vasodilatation in cerebrovascular circulation. This impaired cerebral vascular regulation may contribute to the increased risk of stroke in patients with OSAS.

Is overactive bladder a nervous or bladder disorder? Autonomic imaging in patients with overactive bladder via dynamic pupillometry.

PURPOSE: To evaluate the changes in dynamic pupillometry in patients with idiopathic overactive bladder (OAB). METHODS: The study included 40 female patients with idiopathic OAB and 40 healthy female volunteers as a control group. Demographic and clinical data were recorded. Dynamic pupillometric parameters were measured with a commercially available unit (MonPack One, Metrovision, France) at baseline and on the 30th day of treatment with an antimuscarinic treatment (drug-agent) (solifenacin 5 mg daily). Initial, minimum, maximum and mean pupil diameters, the latency and duration of contraction and dilatation of the pupil, the amplitude of contraction and dilatation velocity were automatically measured and compared between the groups. RESULTS: There were no significant differences between two groups with respect to age and body mass index (p = 0.288, 0.755, respectively). The measurements of initial, minimum and mean pupil diameters were significantly lower in patients with OAB compared to healthy controls (p = 0.007, 0.002, 0.001, respectively). OAB patients had significantly longer latency of pupil dilatation, latency of pupil contraction and shorter duration of pupil contraction than control group (p = 0.028, 0.029, 0.021, respectively). After the antimuscarinic treatment, latency of pupil contraction, latency of pupil dilatation and duration of pupil contraction shortened significantly (all p < 0.001). Pupil dilatation velocity increased significantly during the treatment (p < 0.001). CONCLUSIONS: The dynamic pupillometric findings in this study imply impaired autonomic dysfunction, mostly the increased parasympathetic action, in OAB patients and the modulatory effects of antimuscarinic treatment.

Association of nerve conduction impairment and insulin resistance in children with obesity.

AIM: The objective of our study was to investigate nerve conduction in normoglycemic obese children. METHODS: A total of 60 children with obesity (30 female and 30 male) and 30 healthy children (15 female and 15 male) were enrolled in the study. Insulin resistance (IR) and other metabolic disturbances were investigated and nerve conduction was measured in all participants. Obese children were divided into groups according to the presence of IR. All results were compared between these subgroups. RESULTS: The nerve conduction velocity (NCV) of motor median nerves in the IR+ group was significantly higher than that in the IR- group and lower than that in the control group. The NCV of the motor peroneal nerve in the IR+ group was significantly lower than that in the IR- group. The sensory nerve action potential (SNAP) of the sensory median nerve was significantly lower in the IR+ group compared to that in the IR- group. The sensory sural nerve's SNAP was significantly lower in the IR+ group than that in the control group. CONCLUSION: Nerve conduction tests may help to detect early pathologies in peripheral nerves and to decrease morbidities in obese children.

Visual and brainstem auditory evoked potentials in children with obesity.

AIMS: The aim of our study is to investigate alterations in visual evoked potentials (VEP) and brainstem auditory evoked potentials (BAEP) in children with obesity. METHODS: A total of 96 children, with a mean age of 12.1±2.0 years (range 9-17 years, 63 obese and 33 age and sex-matched control subjects) were included in the study. Laboratory tests were performed to detect insulin resistance (IR) and dyslipidemia. The latencies and amplitudes of VEP and BAEP were measured in healthy and obese subjects. RESULTS: The VEP P100, BAEP interpeak latency (IPL) I-III and IPL I-V averages of obese children were significantly longer than the control subjects. When the obese group was divided into two subgroups, those with IR and without IR, BAEP wave I, wave III and P100 wave latencies were found to be longer in the group with IR. A statistically significant correlation was observed between BAEP wave I latency, IPL I-V, IPL I-III and the homeostatic model assessment insulin resistance (HOMA IR) index and fasting insulin level. CONCLUSIONS: Our findings suggest that VEP and BAEP can be used to determine early subclinical on auditory and visual functions of obese children with insulin resistance.

Reduced breath holding index in patients with chronic migraine.

Migraine is a neurovascular disorder characterized by autonomic nervous system dysfunction and severe headache attacks. Studies have shown that changes in the intracranial vessels during migraine have an important role in the pathophysiology. Many studies have been conducted on the increased risk of stroke in patients with migraine, but insufficient data are available on the mechanism underlying the increase. This study aimed to evaluate basal cerebral blood flow velocity and vasomotor reactivity in patients with chronic migraine. We evaluated 38 patients with chronic migraine. Three of them were excluded because they had auras and four of them were excluded because of their use of medication that can affect cerebral blood flow velocity and breath holding index (beta or calcium channel blockers). Our study population consisted of 31 patients with chronic migraine without aura and 29 age- and gender-matched healthy individuals who were not taking any medication. The mean blood flow velocity and breath holding index were measured on both sides from the middle cerebral artery and posterior cerebral artery, with temporal window insonation. The breath holding index for middle cerebral artery and posterior cerebral artery was significantly lower in the migraine group compared to that of the control group (p < 0.05).The vasomotor reactivity indicates the dilatation potential of a vessel, and it is closely related to autoregulation. According to our results, the vasodilator response of cerebral arterioles to hypercapnia was lower in patients with chronic migraine. These findings showed the existence of impairments in the harmonic cerebral hemodynamic mechanisms in patients with chronic migraine. This finding also supports the existing idea of an increased risk of stroke in patients with chronic migraine due to impaired vasomotor reactivity.

Strength-duration time constant in peripheral nerve: no abnormality in multiple sclerosis.

Objectives. To investigate the properties of the strength-duration time constant (SDTC) in multiple sclerosis (MS) patients. Methods. The SDTC and rheobase in 16 MS patients and 19 healthy controls were obtained following stimulation of the right median nerve at the wrist. Results. SDTC and rheobase values were 408.3 ± 60.0 µs and 4.0 ± 1.8 mA in MS patients, versus 408.0 ± 62.4 µs and 3.8 ± 2.1 mA in controls. The differences were not significant in SDTC or rheobase values between the patients and controls (P = 0.988 for SDTC and P = 0.722 for rheobase). Conclusion. Our study showed no abnormality in relapsing remitting MS patients in terms of SDTC, which gives some indirect information about peripheral Na(+) channel function. This may indicate that alterations in the Na(+) channel pattern in central nervous system (CNS) couldnot be shown in the peripheral nervous system (PNS) in the MS patients by SDTC. The opinion that MS can be a kind of channelopathy might be proven by performing other axonal excitability tests or SDTC in progressive forms of MS.

The effects of low-dose radiation in the treatment of sciatic nerve injury in rats.

AIM: Peripheral nerve regeneration is often blocked by scar formation and misdirection of axon sprouts. The aim of this study is to evaluate electrophysiological and histopathological effects of low-dose radiation therapy on the prevention of intraneural scar formation in peripheral nerve injury. MATERIAL AND METHODS: In this experimental study, twenty rats were randomly divided into two groups. Left sciatic nerves were exposed and clipped by temporary aneurysm clip for 5 minutes in both groups. In all animals, electrophysiological recordings were performed between 22-24 hours after sciatic nerve injury. The control group was not given any treatment. In the experimental group, 700 cGy low-dose radiation was administered on the left sciatic nerves 24 hours after clipping. Six weeks after injury, electrophysiological recordings were performed in both groups and animals were sacrificed to evaluate the injured nerves histopathologically. RESULTS: We observed that low-dose radiotherapy increased the amplitude and improved latency measurements in electrophysiological examinations. Histopathologically, more axonal degeneration and vacuolization was observed in the control group comparing with the experimental group. Endoneural space increased slightly more in the control group than the experimental group. CONCLUSION: It was observed that low-dose radiotherapy may prevent intraneural scar formation and may improve electrophysiological recovery in sciatic nerve injury performed in rats.

[Botulinum neuro-toxin aype-A in the treatment of chronic tension type headache associated with pericranial tenderness]. / Perikranial hassasiyet ile iliskili kronik gerilim tipi bas agrisinda botulinum toksin tip A tedavisi.

OBJECTIVES: Both peripheral and central nociceptive mechanisms are responsible in chronic TTH. Analgegics are used in the acute treatment of chronic TTH and antidepressants are used in prophylactic treatment. However, further studies are needed to bring out new treatment options. The aim of our study is to investigate the effectiveness of Botulinum Neuro-toxin Type-A (BoNTA) in the treatment of chronic TTH associated with pericranial tenderness (PT). METHODS: 14 patients with chronic TTH with PT were included in the study. 50 units Botox(®) injection was applied to the pericranial muscles (5 units for each muscles bilaterally: frontal, temporal, semispinalis capitis, spenius capitis and trapezius muscles) for each patient. Severity of headache was evaluated by VAS (Visual Analogue Scale) and number of days with headache per month were recorded before treatment and 2nd and 4th months after treatment. RESULTS: Number of days with headache per month were 19.57 ± 3.25 before treatment, 15.28 ± 4.37 at the 2nd month after treatment and 15.78 ± 3.90 at the 4th month after treatment. Severity of headache was 65.71 ± 9.16 before the treatment, 50.71 ± 13.56 at the 2nd month after treatment and 54.28 ± 10.35 at the 4th month after treatment (p<0.05). Frequency and severity of headache before treatment were significantly decreased at the 2nd month after treatment and this significance continued at the 4th month after treatment (p<0.05). CONCLUSION: BoNTA treatment may be usefull in the treatment of patients with chronic TTH associated with PT.

The efficacy of botulinum toxin in patients with cervicogenic headache: a placebo-controlled clinical trial.

OBJECTIVE: Botulinum toxin type-A (BoNTA) has been considered a treatment option for CH. The aim of this study was to assess the effectiveness of BoNTA treatment in patients with medically resistant CH. MATERIALS AND METHODS: Forty patients with CH were included in the study. Patients in the BoNTA group (n=20) were administered 10 U of BoNTA bilaterally to the frontal muscles, 20 U to the temporal muscles, 15 U to the semispinalis capitis, 15 U to the splenius capitis, and 15 U to the trapezius muscles (total: 150 U). Patients in the placebo group (n=20) received 0.2 mL of saline administrated to the same sites. All participations were evaluated 6 and 12 weeks after treatment; side effects, the number of painful days, severity (by visual analogue scale, VAS) and frequency of pain were evaluated. RESULTS: In the BoNTA group, the severity and frequency of pain 6 and 12 weeks post treatment were significantly lower than pre-treatment levels (p<0.05). At 12 weeks post treatment, the severity and frequency of pain in the BoNTA group were lower than in the placebo group (p<0.05). CONCLUSION: The findings suggest that BoNTA was an effective treatment for CH.

Cerebral venous thrombosis presenting with subarachnoid hemorrhage after spinal anesthesia.

A 22-year-old male had a meniscopathy operation using spinal anesthesia. After the operation, the patient reported a throbbing headache. His brain computed tomography (CT) showed subarachnoid hemorrhage (SAH) and hyperdense dural venous sinuses suspicious for thrombosis. Filling defects were observed in the superior sagittal and right transverse sinuses on the contrast-enhanced magnetic resonance images. The patient was diagnosed with cerebral venous sinus thrombosis (CVST). On the tenth day of his admission, his clinical findings progressed and heparin therapy was initiated after resorption of hemorrhage was observed in a second non-contrast CT scan. The patient developed decreased consciousness the day after heparin administration. A subsequent brain CT revealed intraparenchymal hemorrhage in the right anteroinferior frontal region. Heparin therapy was discontinued, and anti-edema therapy was started. The presentation of CVST with SAH is a rare condition. Furthermore, development of CVST after spinal anesthesia is very rare. In this case, CVST developed after spinal anesthesia, and its first clinical presentation was SAH. To our knowledge, this is the first case CVST presenting with SAH after spinal anesthesia.

Implications of tilt-table induced faint time in patients with reflex syncope.

OBJECTIVE: The aim of this study was to determine whether patients who faint earlier in the course of a tilt table study represent a separate population with a poorer prognosis or different pathophysiology. We analyzed differences across patients with different syncopal times on the tilt-table study to answer this question. METHODS: This was a retrospective, approved, chart review. From our database of over 6000 patients, we identified 1222 patients with syncope. After excluding patients with orthostatic hypotension, postural tachycardia syndrome and diabetes, we were left with 131 patients with pure reflex syncope. We divided fainters into an early (<20 minutes) and late (>20 minutes) faint times. Along with the tilt table test all patients underwent heart rate response for deep breathing, Valsalva maneuver and quantitative sudomotor axon reflex tests. RESULTS: By 10 minutes in the tilt study, only 18% of subjects had fainted, 65% by 20 minutes, 92% by 30 minutes and 96% by 35 minutes. Age was evenly distributed across all syncopal times. Neither the 14 abnormal cardiac responses to deep breathing nor the 20 abnormal Valsalva maneuvers, nor the 28 abnormal axon reflex responses clustered with an early or late faint time. CONCLUSION: A 10-minute tilt will miss 82% of syncopal episodes, while a 30- minute tilt increases the yield 10-fold, missing only 8%. Patients with early faint times did not differ from patients with late fainting times with regard to age or autonomic test abnormalities. Timing of syncope during the tilt table test does not associated with more severe dysautonomia. A prospective study is needed to confirm these observations.

Electrophysiological assessment of the autonomic nervous system in male patients with acromegaly.

BACKGROUND/AIMS: We aimed to electrophysiologically evaluate the autonomic function in acromegalic patients using sympathetic skin response (SSR) as a reflection of the sympathetic sudomotor activity and RR interval variation (RRIV) as an indicator of the cardiovagal autonomic function. METHODS: The study group consisted of 18 male acromegalics, and the control group was composed of 18 age- and sex-matched healthy subjects. Participants underwent SSR and RRIV tests. Beginning latencies and amplitudes of the median and tibial SSRs were compared among the groups. The RRIV values recorded at rest and during hyperventilation were compared among the patients and controls. RESULTS: Latencies of SSRs recorded from the palms (median) and soles (tibial) of acromegalics were significantly longer than in healthy subjects (p = 0.004, p < 0.001). The amplitude of SSR recorded from the sole (tibial) was significantly decreased (p = 0.028). The RRIVs obtained from acromegalics at rest and during hyperventilation were significantly decreased compared with those of controls (p < 0.001). The RRIVs obtained from controls prolonged significantly during hyperventilation (p < 0.001); however, in the acromegaly group, hyperventilation did not cause a significant change in RRIV (p = 0.983). CONCLUSIONS: The present study suggests that an autonomic dysfunction exists in patients with acromegaly. Dysautonomia in acromegalics may be documented by means of SSR and RRIV.

P300 auditory event-related potentials in children with obesity: is childhood obesity related to impairment in cognitive functions?

OBJECTIVE: To investigate alterations in P300 auditory event-related potentials in children with obesity to detect changes in cognitive functions. METHOD: A total of 50 children with obesity and 23 age- and sex-matched healthy control subjects were included in the study. Laboratory tests were performed to detect dislipidemia and insulin resistance (IR). The latencies and amplitudes of P300 waves were measured in healthy and obese subjects with or without IR. The oddball paradigm was used in recordings of P300 auditory event-related potentials. RESULTS: A significant difference was observed between groups regarding latency and amplitude of P300 component obtained from central (Cz) electrode. The grand means of P300 latency were longer, and amplitude decreased significantly in obese group compared to that of healthy controls. When the obese group was divided into two different subgroups, those with IR and without IR, the grand means of P300 latency were longer and the amplitude decreased significantly in subjects with IR compared to those without IR. CONCLUSION: Both decreased amplitude and prolonged latency of P300 are associated with IR in children with obesity, which shows the impairment of neural activity associated with sensory and cognitive information processing in these children. Further studies are necessary to strengthen the current findings and to determine the exact mechanism of cognitive impairment in obese children.

The effectiveness of triamcinolone acetonide vs. procaine hydrochloride injection in the management of carpal tunnel syndrome: a double-blind randomized clinical trial.

OBJECTIVE: Corticosteroid injection into the carpal tunnel is frequently used for the treatment of carpal tunnel syndrome (CTS). Steroids are usually mixed with local anesthetics, which have positive effects that can aid the treatment of CTS by inhibiting the spontaneous discharge ability of excitable cells. The aim of this study was 3-fold: (1) to determine the efficacy of triamcinolone acetonide injection in the treatment of CTS, (2) to determine the efficacy of procaine hydrochloride (HCl) in the treatment of CTS, and (3) to compare the efficacy of triamcinolone acetonide and that of procaine HCl in the treatment of CTS. DESIGN: This prospective, randomized, double-blind clinical trial included 99 patients (120 median nerves) with clinical and electrophysiologic evidence of CTS. The 120 median nerves were randomly assigned to one of three groups: group 1 received 40 mg of triamcinolone acetonide, group 2 received 4 ml of 1% procaine HCl, and group 3 received both 40 mg of triamcinolone acetonide and 4 ml of 1% procaine HCl. Clinical and electrophysiologic evaluations were performed at the study onset and at 2 and 6 mos after treatment. RESULTS: At the study onset, there were no statistically significant differences between the groups with respect to distal motor latency, compound motor action potential, compound sensory action potential, sensory nerve conduction velocity, or visual analog scale score; however, distal motor latency, compound sensory action potential amplitude, sensory nerve conduction velocity, and visual analog scale scores improved significantly in each group 2 mos after treatment (P < 0.05), and these improvements persisted at 6 mos after treatment (P < 0.05). Significant differences were not observed between groups 1 and 2 or between groups 1 and 3 with respect to electrophysiologic findings at baseline or 2 or 6 mos after treatment (P > 0.05). Group 3 had better compound sensory action potential amplitude and sensory nerve conduction velocity scores than group 2 did at 6 mos (P < 0.05) and better visual analog scale scores than group 2 did at 2 and 6 mos (P < 0.05). CONCLUSIONS: Local procaine HCl injection and steroid injection effectively reduced the symptoms of CTS and equally improved electrophysiologic findings. As such, procaine HCl can be used in CTS patients in whom steroid use is contraindicated.

Hot water epilepsy: seizure type, water temperature, EEG findings and treatment.

OBJECTIVES: Hot water epilepsy (HWE) or bathing epilepsy is one of the reflex epilepsies induced by hot water pouring over the head, face, neck, or trunk during bathing. The aim of this study was to demonstrate the clinical and electroencephalographic features and the management alternatives of the patients with HWE. METHODS: The age of seizure onset, duration of seizure, family history, interictal and postictal electroencephalography findings, triggering temperature of water, type of seizure, medication, and follow-up results were evaluated for each patient. RESULTS: The mean age at seizure onset was 10.5 years. The mean duration of seizures was 10 years. Interictal EEG recordings showed focal abnormalities in 4 patients and generalized abnormalities in 3 patients. Only one patient had normal interictal EEG findings. Among the 8 patients with HWE, 6 had seizures only during hot bathing, whereas 2 had additional seizures. Seven patients had generalized tonic-clonic seizures and 1 patient had complex partial seizure during their hot bathings. The mean triggering temperature of water was calculated as 41.4 degrees C. The mean duration of follow-up period was 23 months. Five patients became seizure-free during the follow-up period and seizures persisted in 3 patients. Antiepileptic drugs were given (800 mg/d carbamazepine for 2 patients and 600 mg/d phenytoin for 1 patient) to these 3 patients and they also became seizure-free during the follow-up period. CONCLUSIONS: Hot water epilepsy is a benign reflex epilepsy. Lowering water temperature must be the first step for the treatment. If needed, antiepileptic drugs should be considered as an additive treatment.

Electrophysiological findings in patients with adult tethered cord syndrome.

AIM: This study was planned for detailed evaluation of electrophysiological findings in patients with adult TCS. MATERIAL AND METHODS: Patients were retrospectively assessed for clinical, radiological and electrophysiological data between 1999 and 2008. Tibial somatosensorial evoked potentials, needle electromyography, nerve conduction studies and late responses (H reflex and F response) were studied in thirty (1 female, 29 males) TCS patients diagnosed by lumbar magnetic resonance imaging. RESULTS: Tibial somato-sensorial evoked potentials cortical response latency was abnormal in 18 (60%) patients. Needle electromyography revealed chronic neurogenic involvement in 13 (43.3%) patients. In nerve conduction studies, motor unit action potential amplitudes were reduced in 5 (16.6%) patients and H reflexes were abnormal in 13 (43.3%) patients. CONCLUSION: Different electrophysiological abnormalities may be seen in patients with adult TCS. Our results indicated that tibial SEP abnormalities are most sensitive electrophysiological finding in patients with adult TCS. Patients with TCS should undergo electrophysiological examinations whether they have subjective or objective complaints. These examinations should evaluate different systems and treatment planning should be done with the data obtained.