Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Sibel Karaca is active.

Publication


Featured researches published by Sibel Karaca.


Headache | 2006

Is low blood magnesium level associated with hemodialysis headache

Başak Karakurum Göksel; Dilek Torun; Sibel Karaca; Mehmet Karatas; Meliha Tan; Nurzen Sezgin; Sibel Benli; Siren Sezer; Nurhan Ozdemir

Objective.—The aim of this study was to evaluate the prevalence, demographic, clinical features, and possible risk factors for hemodialysis headache (HDH).


International Journal of Neuroscience | 2008

Unertan syndrome: a case series demonstrating human devolution.

Uner Tan; Sibel Karaca; Meliha Tan; Bekir Yilmaz; Namik Kemal Bagci; Ayhan Ozkur; Sadrettin Pence

A large family with six individuals exhibiting the Unertan syndrome (UTS) was identified residing in southern Turkey. All of the individuals had mental impairments and walked on all four extremities. The practice of intra-familial marriages suggested that the UTS may be an autosomal recessive disorder, similar to previously described cases. The inferior portions of the cerebellum and vermis were absent as evidenced by MRI and CT scans. The height and head circumference of those affected were within normal ranges. Baranys test suggested normal vestibular system function. The subjects could not name objects or their close relatives. The males (n = 4) could understand simple questions and commands, but answered questions with only one or two sounds. The females (n = 2) were superior to the males with respect to language skills and walking, suggesting an association between walking and speaking abilities. One male exhibited three walking patterns at the same time: quadripedal, tiptoe, and scissor walking. Another male used two walking styles: quadripedal and toe-walking. It is emphasized that there are important differences between the UTS and the disequilibrium syndrome. It is suggested that the inability to walk upright in those affected with the UTS may be best explained by a disturbance in lateral-balance mechanisms, without being related to the cerebello-vestibular system. An interruption of locomotor development during the transition from quadripedality to bipedality may result in habitual walking on all four extremities and is normal in some children. Because quadripedal gait is an ancestral trait, individuals with the UTS, exhibiting a manifestation of reverse evolution in humans, may be considered an experiment of nature, useful in understanding the mechanisms underlying the transition from quadripedality to bipedality during human evolution. The proposed mutant gene or gene pool playing a role in human quadrupedality may also be responsible for human bipedality at the same time. Herein there is no intent to insult or injure; rather, this report is an endeavor to better understand human beings. Supplementary materials are available for this article. Go to the publishers online edition of International Journal of Neuroscience for the following free supplemental resource(s): video clips.


Archive | 2012

Üner Tan Syndrome: Review and Emergence of Human Quadrupedalism in Self-Organization, Attractors and Evolutionary Perspectives

Uner Tan; Yusuf Tamam; Sibel Karaca; Meliha Tan

The first man reported in the world literature exhibiting habitual quadrupedal locomotion was discovered by a British traveler and writer on the famous Baghdat road near Havsa/Samsun on the middle Black-Sea coast of Turkey (Childs, 1917). Interestingly, no single case with human quadrupedalism was reported in the scientific literature after Childs first description in 1917 until the first report on the Uner Tan syndrome (UTS: quadrupedalism, mental retardation, and impaired speech or no speech)in 2005 (Tan, 2005, 2006). Between 2005 and 2010, 10 families exhibiting the syndrome were discovered in Turkey with 33 cases: 14 women (42.4%) and 19 men (57.6%). Including a few cases from other countries, there were 25 men (64.1%)and 14 women (35.9%). The number of men significantly exceeded the number of women (p < .05). Genetics alone did not seem to be informative for the origins of many syndromes, including the Uner Tan syndrome. From the viewpoint of dynamical systems theory, there may not be a single factor including the neural and/or genetic codes that predetermines the emergence of the human quadrupedalism.Rather, it may involve a self-organization process, consisting of many decentralized and local interactions among neuronal, genetic, and environmental subsystems. The most remarkable characteristic of the UTS, the diagonal-sequence quadrupedalism is well developed in primates. The evolutionarily advantage of this gait is not known. However, there seems to be an evolutionarily advantage of this type of locomotion for primate evolution, with regard to the emergence of complex neural circuits with related highly complex structures. Namely, only primates with diagonal-sequence quadrupedal locomotion followed an evolution favoring larger brains, highly developed cognitive abilities with hand skills, and language, with erect posture and bipedal locomotion, creating the unity of human being. It was suggested that UTS may be considered a further example for Darwinian diseases, which may be associated with an evolutionary understanding of the disorders using evolutionary principles, such as the natural selection. On the other hand, the human quadrupedalism was proposed to be a phenotypic example of evolution of reverse, i.e., the reacquisition by derived populations of the same character states as those of ancestor populations. It was also suggested that the emergence of the human quadrupedalism may be related to self-organizing processes occurring in complex systems, which select or attract one preferred behavioral state or locomotor trait out of many possible attractor states. Concerning the locomotor patterns, the dynamical systems in brain and body of the developing child may prefer some kind of locomotion, according to interactions of the internal components and the environmental conditions, without a direct role of any causative factor(s), such as genetic or neural codes, consistent with the concept of self-organization, suggesting no single element may have a causal priority.


Journal of Clinical Neuroscience | 2009

Health-related quality of life of patients with epilepsy in Turkey.

Semih Giray; Yarkın Özenli; Handan Ozisik; Sibel Karaca; Umit Aslaner

The aim of this study was to measure the health related quality of life (HRQOL) of epilepsy patients and to compare it with that of a healthy control group. The evaluation included the effects of the type of seizure, duration of seizure and medical treatment on the quality of life of the patients. The group studied consisted of 221 participants (121 epilepsy patients and 100 healthy control individuals) who completed a sociodemographic data form and who were administered the World Health Organization Quality of Life (WHOQOL-100) scale. The epilepsy patients had statistically lower physical health, psychological well-being, level of independence and global HRQOL than participants in the control group (p<0.05). The analysis of variance showed that the partial epilepsy subgroup had significantly lower averages for all the quality-of-life subfields except for the social relationship dimension. On regression analysis, being married, having a generalized type of seizure and being treated with fewer medications were all related to higher scores on the HRQOL. Epilepsy is a disease that has neurological, psychiatric and psychosocial dimensions that should be evaluated using a multidisciplinary approach.


European Journal of Radiology | 2010

Cranial involvement in sickle cell disease

Özlem Alkan; Ebru Kizilkilic; Osman Kizilkilic; Tulin Yildirim; Sibel Karaca; Mahmut Yeral; Mutlu Kasar; Hakan Ozdogu

PURPOSE To evaluate cranial findings in patients with neurologically symptomatic sickle cell disease (SCD). MATERIALS AND METHODS We studied 50 consecutive patients with SCD and neurologic symptoms. All patients underwent brain MR examinations: all 50 underwent classic MR imaging; 42, diffusion-weighted MR imaging; 10, MR angiography; four, MR venography; and three patients, digital subtraction angiography. RESULTS Of the 50 SCD patients, 19 (38%) had normal MR findings, and 31 (62%) showed abnormalities on brain MR images. Of the 50 patients, 16 (32%) had ischemic lesions; two (4%), subarachnoid hemorrhage; one (2%), moya-moya pattern; one (2%), posterior reversible encephalopathy; one (2%), dural venous sinus thrombosis; 12 (24%), low marrow signal intensity and thickness of the diploic space; 12 (24%), cerebral atrophy; and two (4%), osteomyelitis. Twenty-seven patients (54%) presented with headache, which was the most common clinical finding. CONCLUSIONS The cranial involvement is one of the most devastating complications of SCD. Early and accurate diagnosis is important in the management of cranial complications of SCD.


Strabismus | 2008

Rhombencephalosynapsis Associated with Infantile Strabismus

Silay Canturk; Sibel Oto; Osman Kizilkilic; Sibel Karaca; Yonca A. Akova

Introduction: Malformations of the cerebellum have been well-known to coexist with abnormalities of the oculomotor system. Rhombencephalosynapsis (RES) is a rare malformation of the cerebellum of unknown etiology in which the vermis is hypoplastic and the two cerebellar hemispheres are fused. The type of oculomotor disorders associated with RES is not well documented in the literature. Here, two cases are presented.Case 1: A 15-year-old girl presented with large-angle infantile esotropia and inferior oblique overaction. Slow (3 to 4 cps) rhythmic anteroposterior oscillation movement of the head was observed while walking and left-sided postural tremor was present. Case 2: An 8-month-old baby girl presented with facial dysmorphism, right esotropia, anisometropia, motor delay and truncal ataxia. Cranial MRI demonstrated RES in both patients. Conclusion: The clinical findings in two children presenting with infantile esotropia and RES may suggest a role of the vermis in ocular alignment. Head nodding in a child with strabismus can be observed only when walking and its presence should prompt neuroimaging.


Frontiers in Neurology | 2012

Human quadrupedalism is not an epiphenomenon caused by neurodevelopmental malformation and ataxia.

Sibel Karaca; Meliha Tan; Uner Tan

Two cases with quadrupedal locomotion (QL) were presented. In both cases, cognitive and psychiatric functions were normal and, no neurological deficits were observed, except for a sequel paralysis of left leg in Case 2. It was suggested that human QL (1) should not be considered as an epiphenomenon caused by neurodevelopmental malformation and ataxia, but (2) may be considered as a re-emergence of the ancestral diagonal QL, and (3) it may spontaneously emerge in humans with entirely normal brains, by taking advantage of neural networks such as central pattern generators that have been preserved for about 400 million years.


Neurological Research | 2007

Subclinical hypothyroidism, hyperhomocysteinemia and dyslipidemia: investigating links with ischemic stroke in Turkish patients

Başak Karakurum Göksel; Mehmet Karatas; Asuman Nebioglu; Nurzen Sezgin; Meliha Tan; G. Seydaoglu; Sibel Benli; Sibel Karaca; Zülfikar Arlier; Deniz Yerdelen

Abstract Objectives: Hyperhomocysteinemia is a risk factor for ischemic stroke. Hypothyroidism may cause hyperhomocysteinemia. To date, no works have examined the association between hypothyroidism and hyperhomocysteinemia in ischemic stroke. We aimed to investigate the roles of hypothyroidism and hyperhomocysteinemia in ischemic stroke, and whether any relationship exists between hypothyroidism and hyperhomocysteinemia in ischemic stroke patients. Methods: The study included 249 ischemic stroke patients and 102 patients with no history of stroke. Patients were evaluated for conventional risk factors and levels of homocysteine, thyroid-stimulating hormone, vitamin B12 and folic acid. Results: Ten (4%) patients in the ischemic stroke group had subclinical hypothyroidism. We did not find any overt or subclinical hypothyroidism in the control group. Hypothyroidism was higher to a statistically significant degree in the ischemic stroke group (p<0.05). Both hyperhomocysteinemia and hypothyroidism were associated with ischemic stroke patients. However, no association was found between hyperhomocysteinemia and hypothyroidism. Ischemic stroke patients with hypothyroidism had lower levels of HDL cholesterol and levels of total cholesterol/HDL-C and LDL-C/HDL-C were higher than those of ischemic stroke patients without hypothyroidism. Discussion: Hypothyroidism is associated with ischemic stroke. Low HDL cholesterol, high total cholesterol/HDL-C and high LDL-C/HDL-C were associated in ischemic stroke patients with hypothyroidism. Hyperhomocysteinemia was not found to be associated with ischemic stroke patients with hypothyroidism.


Nöro Psikiyatri Arşivi | 2014

Nörologlar Nasıl Primer Sjögren Sendromu Tanısı Koyar

Ahmet Eftal Yücel; Başak Karakurum Göksel; Emine Duygu Ersozlu Bozkirli; Meliha Tan; Sibel Karaca

INTRODUCTION Neurological involvements were shown in 20% of patients with Primary Sjogrens Syndrome (pSS). Neurological symptoms may be the first signs of pSS in 57% of the cases. In addition, early diagnosis and treatment of neurological disorders may save or improve the quality of life of these cases. There have been reports about the neurologic manifestations of pSS but little is known about the details of neurologically presented cases. METHOD In this study, we described 11 pSS patients who presented with neurological manifestations. RESULTS Central nervous system (CNS) involvement was recorded in 7 (63.7%) and peripheric nervous system (PNS) involvement in 4 cases (36.4%). CONCLUSION Our findings regarding the cases with neurological manifestations leading to the diagnosis of pSS suggest that: 1) The frequency of CNS involvement was higher than that of PNS, and the most frequent clinical pictures of CNS involvement are Multiple Sclerosis (MS)-like illnesses and optic neuritis, 2) Guillain Barre Syndrome (GBS) was the most frequent disease of PNS involvement; 3) Mononeuropathy multiplex (MM) might be the first sign of pSS; 4) Neurologists should consider pSS in the differential diagnosis of cases with MS, optic neuritis, GBS and neuropathies of unknown causes including MM; 5) There is an urgent need of therapeutical guidelines for the cases with neurological involvement associated with pSS.


Archive | 2013

Humans Walking on all Four Extremities with Mental Retardation and Dysarthric or no Speech: A Dynamical Systems Perspective

Sibel Karaca; Meliha Tan; Uner Tan

Locomotion is the movement of an organism from one place to another, often by the action of appendages such as flagella, limbs, or wings. In some animals, such as fish, a lumbering locomotion results from a wavelike series of muscle contractions (The American Heritage® Science Dictionary, 2005). Walking is travelling by foot; gait is the manner of locomotion; running is the act of travelling on foot at a fast pace; crawling is a slow mode of hand-knee or hand-foot locomotion. Walking on all four extremities (quadrupedal locomotion, QL) is the trait of the quadruped animals. Non-primate mammals usually utilize lateral-sequence QL, in which the hind limb touchdowns are followed by the ipsilateral forelimb touchdowns (symmetric gait). On the contrary, the non-human primates usually utilize a diagonalsequence QL, in which the hind-limb moves with the contralateral forelimb in a diagonal couplet (asymmetric gait). Interestingly, only the animals exhibiting the diagonal-sequence QL with symmetrical gait evolved towards species with enlarged brains associated with highly complex neural circuits, till the emergence of human beings. The animals exhibiting lateralsequence QL did not show such a phylogenetic progress compared to those with diagonalsequence QL. Figure 1 shows the differences between lateral-(left) and diagonal-sequence (right) patterns of QL.

Collaboration


Dive into the Sibel Karaca's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Uner Tan

Çukurova University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Semih Giray

University of Gaziantep

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge