Sibel Ozkaynak

Recovery cycle of the blink reflex and exteroceptive suppression of temporalis muscle activity in migraine and tension-type headache.

Brain stem interneuronal excitability can be assessed by recording the recovery cycle of the blink reflex and exteroceptive suppression of temporalis muscle activity. Abnormal endogenous pain control mechanisms due to disturbed brain stem interneuronal activity have been implicated in the pathogenesis of tension‐type headaches. The blink reflex, exteroceptive suppression of temporalis muscle activity, and the recovery curve of both the R2 component of the blink reflex and the ES2 component of the exteroceptive suppression of the temporalis muscle activity were studied in 20 patients with migraine without aura, 32 patients with tension‐type headache, and 20 normal controls. In our study, the blink reflex was elicited by stimulation of the supraorbital nerve; the exteroceptive suppression of the temporalis muscle activity was elicited by applying electrical shocks to the labial commissure, both on the lower and upper sides. The recovery cycle was established by delivering paired shocks at different interstimulus intervals. Comparisons were made between normal control subjects, patients with migraine without aura, and patients with tension‐type headache. The latency of R1, R2, and R2′, the amplitude and size of the R2 and R2′ components of the blink reflex, the latency and duration of the ES1 and ES2 components, and the recovery curve of the ES2 component of the temporalis muscle activity did not differ between groups. However, the recovery curve of the R2 component of the blink reflex diminished in patients with tension‐type headache compared with the other groups. Our findings indicate reduced excitability of the brain stem interneurons in patients with tension‐type headache.

Results of zone II flexor tendon repair in children younger than age 6 years: botulinum toxin type A administration eased cooperation during the rehabilitation and improved outcome.

The inability of young children with a zone II flexor tendon repair to cooperate in postoperative care and rehabilitation may represent a high risk for medical and surgical complications. To forestall that risk, botulinum toxin type A (2.5 U/kg, 7 U/kg) injection was used during surgery to induce forearm flexor muscle relaxation in seven children under 6 years old with zone 2 flexor tendon repairs. Patients received a controlled passive motion regimen after surgery. Results were evaluated on the basis of the acquisition of muscle tone and active finger movements, total range of motion of affected joints, postoperative grip strength, muscle atrophy, and phalangeal length. In this prospective clinical study, the mean follow-up was 18 months. All the children had good and excellent results based on the Strickland criteria. As for postoperative complications, one patient had bowstring and another had poor finger sensibility and first web space contracture that required Z-plasty. The selective use of botulinum toxin type A to weaken the targeted muscles generated a sufficient reduction in spontaneous activity of the fingers, permitting an improved rehabilitation program. Botulinum toxin type A administration could be an effective form of therapy, serving as an alternative or adjunct to conventional rehabilitation modalities in these children.

Median nerve excursion during endoscopic carpal tunnel release.

OBJECTIVE:Restriction of the excursion of the nerve has been accepted as a pathogenetic element in carpal tunnel syndrome. The goal of this article was to evaluate the median nerve excursion in the carpal tunnel measured as a function of wrist position before and after endoscopic carpal tunnel release (ECTR) on 28 hands of 22 patients. METHODS:The position of cylindrical stainless steel markers embedded within the median nerve was measured by a direct radiographic technique. Each upper extremity was examined in three wrist positions. Then, endoscopic release with Menon’s technique was performed, and the measurements were repeated. RESULTS:In this prospective clinical study, most (93%) of the patients experienced resolution of their symptoms. Before and after ECTR, median nerve excursion was linear and was affected by wrist position. Before ECTR, when the wrist was moved from the end of dorsiflexion to the end of palmar flexion, the median nerve underwent a mean total excursion of 28.8 mm at the wrist. A comparison of the before and after ECTR excursion showed no statistical differences in the amount of motion. CONCLUSION:The single-portal ECTR does not seem to influence the median nerve excursion for the wrist positions studied in patients with carpal tunnel syndrome. The results from this in vivo study showed longitudinal gliding of the median nerve twice as great as in in vitro studies.

Evaluation of the lateral instability of the ankle by inversion simulation device and assessment of the rehabilitation program

OBJECTIVES To assess the correctibility of the muscle atrophy, proprioceptive loss, and slowing of the reflex arc around the ankle after ankle sprain with rehabilitation. METHODS The study group consisted of 20 cases with chronic instability who had at least two episodes of ankle sprains (mean 20.6 years, range 16-32 years); control group consisted of 20 patients with same demographic characteristics but without instability. Isokinetic muscle strength measurements and proprioceptive evaluations were made using the Cybex device before and 1.5-month after rehabilitation period. Additionally, the inversion simulation device, which was developed together with the mechanical engineering department of our university, was correlated with the EMG device, and response periods of muscles to stimulation were measured. RESULTS The proprioceptive loss present in all cases with ankle instability before treatment significantly improved after effective rehabilitation (p=0.001). It was detected that lengthened peroneal latent periods shortened with effective rehabilitation (p=0.001). Cross-interaction of rehabilitation was shown with the preservation of the difference between the pathologic and normal sides regarding proprioception and peroneal latent periods before and after treatment, without any difference between the control group and the pathologic sides. CONCLUSION After ankle sprains, especially in patients with chronic instability, strengthening of the muscles around the ankle with well-planned proprioceptive exercises helps the patients return to normal living and sports activities, and prevents unnecessary surgery, especially in cases with functional instability.

Electrophysiologic and Neuropsychologic Evaluation of Patients with Centrotemporal Spikes

The present study was designed to evaluate neurocognitive functions with endogenous potentials and neurophysiologic tests in patients with centrotemporal spikes who were not on any medication. Of the patients, 85.7% had seizures, 9.5% had pavor nocturnes, and 4.8% had atypical headache. The patients, especially who had atypical seizures or left-sided epileptic activity, were found to have significant visuomotor function impairment (p <.05). In P300 test, N2P3 amplitude was lower in the patients, particularly who had left sided epileptic activity (p <.05). MMN and LDN results were normal. Serial evaluations of such patients with endogenous potentials and neuropsychological tests may be helpful to show development of neurocognitive impairment.

VEGF polymorphisms and serum VEGF levels in Parkinson's disease

Accumulated data within the recent years demonstrate that reduced levels of VEGF which is a well known angiogenic molecule might cause neurodegeneration in part by impairing neural tissue perfusion, vasoregulation and normal functioning of perivascular autonomic nerves. Additionally, VEGF has been reported to support neuroprotection in dopaminergic neurons by indirect and direct mechanisms and suppress apoptosis in dopaminergic neurons in vitro. The aim of the current study is first to demonstrate whether there is an association between the three common VEGF polymorphisms (-2578C/A, -634C/G and 936C/T) in the VEGF gene and idiopathic Parkinsons disease (IPD) which is a neurodegenerative disease caused by the progressive degeneration of nigrostriatal dopaminergic neurons, and second to see if the serum levels of VEGF is reduced in the patients with IPD. We screened the genotype and allele frequencies of three common functional polymorphisms of VEGF, namely -2578C/A, -634C/G and 936C/T in DNA samples of 126 patients with IPD and healthy control subjects and also we compared the median serum levels of VEGF between these two groups. No association was found between the inspected VEGF polymorphisms and IPD and also no difference was found between the serum VEGF levels of both groups. The current study failed to support the hypothesis that VEGF polymorphisms and/or reduced serum VEGF levels are likely contributors to the neurodegenerative process in IPD.

Tongue tremor in brainstem pilocytic astrocytoma.

An isolated tremor of the tongue developed in a 22-year-old female patient in a minimally conscious state. The patient was diagnosed with brainstem pilocytic astrocytoma. A widespread lesion of the brainstem and cerebellum was evident on cranial magnetic resonance imaging. The pathophysiology of isolated tongue tremor is discussed with the magnetic resonance findings and the relevant literature.

Neurocognitive function in patients with β‐thalassemia major

Background:  Children with β‐thalassemia major (β‐TM) have multiple risk factors for developing cognitive impairment. The aim of the present study was to evaluate cognitive function in patients with β‐TM.

Tc-99m HMPAO brain SPECT findings in mild and moderate Alzheimer's disease: Correlation with event related potentials

We investigated whether brain SPECT findings show any differences between patients with mild and moderate Alzheimers disease (AD) and to compare results with event related potentials (ERPs). Twenty-two patients with mild to moderate AD diagnosed according to NINCDS-ADRDA criteria and 10 age-matched control subjects were included in this prospective study. All subjects underwent ERP recordings and Tc-99m HMPAO brain SPECT study. Cortical perfusion index (CPI) was calculated as the ratio of cortical activity to the cerebellum activity. CPI was found to be statistically lower in bilaterally posterolateral temporal cortex and precuneus in the moderate AD compared to the control group. There was no statistically significant difference between the mild AD and control groups for CPI in any cortical areas. The mean P300 latency was statistically prolonged in the mild and moderate AD compared to the control group. In addition, in moderate AD P300 latency was longer than in mild AD. While the mean P300 amplitude was statistically reduced in moderate AD compared to the control and mild AD, there was no statistically significant difference between the mild AD and control groups. There was a strong negative correlation between P300 latency and CPI in the right and left precuneus in the moderate AD group. The present study suggested that Tc-99m HMPAO SPECT study is the more appropriate technique for patients with moderate AD rather than mild AD. Our results indicated that alterations in ERPs, especially prolongation of P300 latency could be a finding that occurred earlier than the deterioration in cerebral blood flow. We thought that precuneus is closely related to cognitive function and may have an important role in the pathophysiology of AD.

EEG as a part of the decision-making process in the emergency department.

Study objective Although electroencephalography (EEG) is a useful diagnostic tool for patients with a suspected seizure, its value in informing the acute care of patients in the emergency department (ED) remains unclear. The aim of this study is to determine the effects of EEG results on subsequent patient management in or from the ED. Materials and methods This prospective observational study was carried out in the ED of a tertiary-care university hospital. All patients presenting to the ED with seizure or seizure-mimicking symptoms were included in the study. EEG was advised for all patients after an initial evaluation. Before EEG, the ED physician and neurologist were asked clinical questions about the patient. The consistency between the clinical decision of emergency physicians before the EEG report and the final management of patients determined by the consultant neurologist was analyzed. The interobserver reliability of the physicians was determined. Results Overall, 110 patients were enrolled in the study. The sensitivity and specificity of ED physicians’ diagnosis of the presence of seizure were both 88% (95% confidence interval, 79–93 and 62–97%). The interobserver reliabilities and &kgr; values of ED physicians and neurologists were found to be ‘moderate’. Patients with abnormal EEG results were prescribed new medication (P=0.003) and changes in therapy (P=0.59) were more than for patients with normal results. Conclusion As seizure is a clinical event, EEG is not essential for diagnosing the presence of a seizure clinically in the ED. However, the results of EEG provide useful information especially for treatment choices. As the timing of the study affects the diagnostic efficacy of the test, EEG recordings should be performed within 24 h either in ED or in the epilepsy clinic.