Biomedical subjects

K Yaltkaya

Publications and source records attributed to K Yaltkaya.

5 recordsLinked to original sources

PubMed2001

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.

Adult↗

PubMed1997

Bereitschaftpotential in schizophrenia.

BACKGROUND: Several reports have documented the presence of motor abnormalities in schizophrenic patients. METHOD: Thirty schizophrenics and 28 healthy controls were included in the study. Scalp-recorded bereitschaftpotentials (BPs) generated prior to voluntary movements were recorded in all subjects. RESULTS: The early (NSI) and late components of BP and peak negativity were reduced in all schizophrenic patients. In particular, the NSI was reduced in patients with positive symptoms, and the late component in patients with negative symptoms. CONCLUSIONS: These findings provide further support of the involvement of frontal cortex, subcortical structures and their connections in schizophrenia, and highlight some differences between positive and negative symptom clusters.

Adult↗

PubMed1993

Spectral analysis of event related potentials.

Event-related brain potentials (ERPs) of twenty normal subjects with no sign of neurologic diseases were measured by applying nontarget and target stimuli as green and red lights respectively. ERPs were recorded in two experimental conditions that the target stimulus was counted (Test 1) or uncounted (Test 2). The spectral analysis of ERPs recorded for Test 1 and Test 2 were computed by using the Transient Responses Frequency Characteristics (TRFC) method. Amplitude maxima were observed in the frequency bands as indicated: 1-2, 3-4, 5-6, 7-8, 8-12, 13-20, 20.5-36, 36 Hz and higher. When we compared Test 2 with the results of Test 1, we observed a significant decrease in the amplitude mean (decibel) of 1-2 Hz frequency band (p < .05). Repeated measures ANOVAs also showed that dB values of 1-2 Hz between counted and uncounted stimuli were significantly different (p < .04). When the number of subjects displaying amplitude maximum in each frequency band was considered, we have found important differences in 1-2, 3-4 Hz and 5-6 Hz bands.

Adult↗

PubMed1988

Visual evoked potentials in diabetes mellitus.

25 diabetic patients have been studied in order to investigate the possible effects of the disease on the central nervous system by means of pattern shift visual evoked potentials. Patients with diabetic retinopathy, glaucoma and cataract were excluded from the study. Results obtained from a control group of 30 normal subjects were compared to those of the patient group in which sural nerve conduction velocities have also been determined to see whether there is a correlation between peripheral and central involvement of the nervous system. In diabetic patients latency prolongation in the P100 and N140 components were observed. The N90-N140 interpeak latency was also prolonged. In addition, in patients with longstanding diabetes mellitus the incidence of VEP abnormalities was found to be high. Pathologic changes in VEP latencies did not show any correlation with sural nerve conduction abnormalities.

Adolescent↗

PubMed1984

Facioscapulohumeral muscular dystrophy concentrated in the village Cullar, Nevşehir, Turkey.

In this paper genetic, clinical, and epidemiological studies on a muscular dystrophy which originated and is concentrated in the village of Cullar, Nevşehir of inland Turkey, are reported. A pedigree chart has been constructed by careful and repeated inquiries, and both clinical and laboratory examinations have generally been carried out in the field. The condition, facioscapulohumeral muscular dystrophy of Landouzy-Déjérine, has been found to have affected at least 53 individuals, 9 of whom are deceased. Both sexes in six generations are involved as would be expected from a dominant mendelian gene freshly mutated at least 100 years ago. Additionally, some 19 individuals have been described as having the disease or some of its stigmata, but have not been examined by us. Initial signs and symptoms seem to appear early in infancy, though variable, and because of complete dominance, some 75 individuals are at risk. The disease progresses slowly without interfering significantly with survival and reproduction. For prevention the so-called Cullar example measures have been taken to improve the area culturally and socioeconomically.

Adolescent↗