Oguzhan Oz

Normal Anatomical Features and Variations of the Vertebrobasilar Circulation and Its Branches: An Analysis with 64-Detector Row CT and 3T MR Angiographies

Purpose. To determine the normal anatomical features and variations of the vertebrobasilar circulation and its branches in patients who underwent multidetector computed tomography (CT) or magnetic resonance (MR) angiographies of the brain. Methods. 135 patients (male, 83 and female, 52; mean age, 50.1 years) who underwent CT (n = 71) or MR (n = 64) angiographies of the vertebrobasilar vasculature for various reasons were analyzed retrospectively. The right and left distal vertebral arteries (VAs), posterior inferior cerebellar arteries (PICAs), anterior inferior cerebellar arteries (AICAs), superior cerebellar arteries (SCAs), posterior cerebral arteries (PCAs), and posterior communicating arteries (PCoAs) were analyzed individually. Results. In 24.4% of the cases (33/135) right PICA, in 19.3% of the cases (26/135) left PICA, in 17.8% of the cases (24/135) right AICA, and in 18.5% of the cases (25/135) left AICA were absent. In cases without PICA or AICA, there was a statistically significant, moderately or well-developed AICA or PICA on the same side, respectively (P < 0.001). The most common variation was isolated absence of right PICA and was seen in 17.8% of the cases. Conclusions. The anatomic features of the branches of the vertebrobasilar circulation may be different from well-known normal anatomy. CT and MR angiographies allow a precise and detailed evaluation of vertebrobasilar circulation.

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

Tascilar ME, Turkkahraman D, Oz O, Yucel M, Taskesen M, Eker I, Abaci A, Dundaroz R, Ulas UH. P300 auditory event‐related potentials in children with obesity: is childhood obesity related to impairment in cognitive functions?

Effect of pramipexole on cutaneous-silent-period parameters in patients with restless legs syndrome

OBJECTIVE The aim of this study was to investigate cutaneous-silent-period (CSP) parameters in patients with restless legs syndrome (RLS) and examine the effects of treatment on CSP which, to our knowledge, have not been investigated till date. METHODS A total of 25 patients with RLS and 25 healthy volunteers were studied. CSP latency and duration in the upper and lower extremities were examined in the two groups. In RLS patients, the variables were examined before and after pramipexole treatment. RESULTS Lower-extremity CSP latency was longer (106.22±11.69 ms vs. 91.67±8.53 ms; p<0.001) and CSP duration was shorter (35.50±10.91 ms vs. 49.47±6.43 ms; p<0.001) in patients, compared with controls. In the patient group, CSP durations in the upper (40.88±7.95 ms vs. 46.84±10.22 ms; p=0.006) and lower extremities (35.50±10.91 ms vs. 44.91±6.43 ms; p=0.005) were prolonged after treatment, compared with pre-treatment values. CONCLUSIONS Small-fibre neuropathy may exist in RLS. In addition, we suggest that pramipexole may regulate cortical and spinal inhibitory mechanisms. SIGNIFICANCE The use of CSP may aid in the diagnosis of RLS and may be used as a measure of treatment effectiveness.

Cutaneous silent period changes in Type 2 diabetes mellitus patients with small fiber neuropathy.

OBJECTIVE Small myelinated (A-delta) and unmyelinated (C) somatic sensory fibers are initially affected and may be the earliest exhibited sign of neuropathy in glucose dysmetabolism. Cutaneous silent period (CSP) is an inhibitory spinal reflex and its afferents consist of A-delta nerve fibers. The aim of this study was to evaluate CSP changes in Type 2 diabetic patients with small fiber neuropathy. METHODS Forty-three patients and 41 healthy volunteers were included. CSP latency and duration, as well as CSP latency difference of the upper and lower extremities, were examined. RESULTS Nerve conduction studies were within normal limits in both groups. Lower extremity CSP latency was longer (122.1+/-15.5 vs. 96.4+/-6.4 ms; p<0.001), CSP duration was shorter (29.5+/-8.9 vs. 43.1+/-5.0 ms; p<0.001), and latency difference was longer (48.1+/-12.6 vs. 22.7+/-3.7; p<0.001) in patients than controls. The difference was more significant in patients with neuropathic pain. No significant difference existed in upper extremity on CSP evaluation. CONCLUSION The CSP evaluation together with nerve conduction study, has been demonstrated to be beneficial and performance of latency difference in addition to CSP latency and duration may be a valuable parameter in electrophysiological assessment of diabetic patients with small fiber neuropathy. SIGNIFICANCE An additional CSP evaluation may be considered in cases which nerve conduction studies do not provide sufficient information.

Can triptans safely be used for airplane headache

A few cases of airplane headache (AH) have been reported in the literature. Treatment strategies of AHs are also controversial. We followed-up five patients with AH. They were symptom-free during the daytime. Their physical, neurological, and ear-nose-throat examinations were all normal. Blood chemistries, cerebral magnetic resonance imaging, cerebral magnetic resonance imaging angiography, and paranasal sinus tomography studies of the patients were also normal. We preferred triptans because of the possible effect on the mechanism of AH. Patients were recommended to use single-dose of their drugs half an hour prior to flights. All of the patients had a good response to single dose triptan treatment and became headache-free during flights. This is the first study which puts forward the usefulness of the triptans as a safe treatment choice for airplane AH.

Is asymmetric dimethylarginine responsible for the vascular events in patients under antiepileptic drug treatment

Some recent studies indicated that administration of antiepileptic drugs (AEDs) is associated with occlusive vascular diseases. Asymmetric dimethylarginine (ADMA) is an endogenous nitric oxide (NO) synthase inhibitor and increased plasma ADMA levels are associated with cardiovascular morbidity. We hypothesized that elevated plasma ADMA concentrations exist in patients receiving AEDs and administration of AEDs may result in an increased risk of occlusive vascular disease. Thirty five newly diagnosed epilepsy patients participated, patients were classified into two groups according to their antiepileptic drug regimen. In the first group patients were treated with valproic acid (VPA, n=17) (500-1500 mg/day), and in the second group with carbamazepine (CBZ, n=18) (400-1200 mg/day). ADMA levels significantly increased after treatment in both VPA (p=0.002) and CBZ (p=0.024) groups. Homocysteine levels increased in both groups, but the difference was significant only in VPA group (p=0.005). Serum folate levels did not differ in VPA group, but significantly decreased in CBZ group (p=0.006). Vitamin B(12) levels significantly increased in VPA group (p=0.001) but did not differ in CBZ group. Correlation analysis showed that the increases in ADMA and homocysteine levels in the VPA group were higher however the differences between the groups were insignificant. The correlations of the changes between ADMA and other parameters were all insignificant in both VPA and CBZ groups. In conclusion our data suggest that elevated ADMA levels may be responsible for the increased cardiovascular risk in patients with epilepsy under AED therapy.

Color vision versus pattern visual evoked potentials in the assessment of subclinical optic pathway involvement in multiple sclerosis.

Background: Optic pathway involvement in multiple sclerosis is frequently the initial sign in the disease process. In most clinical applications, pattern visual evoked potential (PVEP) is used in the assessment of optic pathway involvement. Objective: To question the value of PVEP against color vision assessment in the diagnosis of subclinical optic pathway involvement. Materials and Methods: This prospective, cross-sectional study included 20 multiple sclerosis patients without a history of optic neuritis, and 20 healthy control subjects. Farnsworth-Munsell (FM) 100-Hue testing and PVEPs to 60-min arc and 15-min arc checks by using Roland-Consult RetiScan® system were performed. P100 amplitude, P100 latency in PVEP and total error scores (TES) in FM 100-Hue test were assessed. Results: Expanded Disability Status Scale score and the time from diagnosis were 2.21 ± 2.53 (ranging from 0 to 7) and 4.1 ± 4.4 years. MS group showed significantly delayed P100 latency for both checks (P < 0.001). Similarly, MS patients had significantly increased total error scores (TES) in FM-100 Hue (P < 0.001). The correlations between TESs and PVEP amplitudes / latencies were insignificant for both checks (P > 0.05 for all). 14 MS patients (70%) had an increased TESs in FM-100 Hue, 11 (55%) MS patients had delayed P100 latency and 9 (45%) had reduced P100 amplitude. The areas under the ROC curves were 0.944 for FM-100 Hue test, 0.753 for P100 latency, and 0.173 for P100 amplitude. Conclusions: Color vision testing seems to be more sensitive than PVEP in detecting subclinical visual pathway involvement in MS.

P50 sensory gating in children and adolescents with ADHD and effects of methylphenidate administration on P50 sensory gating / Dikkat eksikliği hiperaktivite bozukluğu tanılı çocuk ve ergenlerde P50 duyusal kapılama ve metilfenidat tedavisinin P50 duyusal kapılama üzerine etkisi

Objective: The P50 is thought to resect a sensory gating mechanism and prevent information overload in humans. Failure to inhibit the P50 auditory event evoked response can occur in attention deficit hyperactivity disorder (ADHD) patients. The aims of the present study were to examine the inhibition of the P50 auditory event evoked potential and the effects of methyphenidate administration on P50 parameters in children and adolescents diagnosed with ADHD. Methods: Twenty-two drug-free subjects, aged 9-14, who were diagnosed with ADHD (the combined type) according to the DSM-IV criteria, and 18 mentally and physically healthy subjects, aged 9-12, were included in the study. First, P50 parameters were measured in drug-free ADHD subjects and healthy controls. Following this measurement, 10 mg of methylphenidate was administered to the ADHD group. The P50 measurement was repeated 1 hour following methylphenidate administration in the ADHD subjects. The healthy control group was not re-examined. Results: A significant difference was found in P50 test latency, test amplitude, and P50 ratio values between the ADHD group and healthy controls. Significant differences were also found in conditioning latency, test latency, test amplitude, and P50 ratio values between before and after methyphenidate administration in the ADHD group. Conclusions: The results of the present study point out an association between P50 and ADHD and they also show that methyphenidate administration increases the P50 suppression level. Since, this is the first study evaluating sensory gating in children and adolescents with ADHD, it should be considered as a preliminary study. Further studies with large study samples are warranted.

Nerve excitability properties in early preclinical diabetic neuropathy

Diabetic polyneuropathy can be easily diagnosed when the nerve conduction studies are affected. Strength Duration Time (SDTc) reflects nerve excitability properties and was previously used several times to demonstrate the excitability properties of the nerves in the existence of electrophysiologically developed diabetic polyneuropathy. But as we all know, diabetic patients may experience neuropathic symptoms even though their routine nerve conduction studies are normal. SDTc may be useful in this early stages of developing neuropathy. In this study we aimed to evaluate the SDTc properties of diabetic patients in this early preclinic stage. Recently SDTc was commonly studied in the upper extremities but most of the diabetic neuropathies are predominant in the lower extremities. So here we also studied both upper and lower extremities to demonstrate a possible difference.

Superficial radial neuropathy and brachioradial motor nerve palsy associated with proximal radius osteochondroma

The cutaneous branch of the radial nerve (superficial radial nerve, SRN) might be compressed or injured at various anatomical sites along its course in the forearm. Compression of the SRN occurring at the proximal third of the forearm is unusual. A 22-year-old man was admitted with pain and paraesthesia over the lateral aspect of his right wrist and thumb and pain at the elbow for six months. In electrodiagnostic testing, a sensory nerve action potential from the right SRN could not be recorded, while it was normal on the left. In a needle electromyography study, denervation potentials have been seen in the right brachioradial muscle and a decrease in interference pattern signals was also found. An exophytic lesion of the proximal radius was observed in radiographs. Computed tomography evaluation revealed an osteochondroma of the proximal radius. Neuropathies of the SRN and the brachioradial motor branch of the radial nerve are thought to be associated with proximal radial osteochondroma.