Association between cervical curvature and cervical sympathetic symptoms
From: Zhongguo Yi Xue Ke Xue Yuan Xue Bao. 2009 Jun;31(3):381-2
To investigate the association between cervical curvature and cervical sympathetic symptoms, the clinical data of 318 patients with cervical spondylosis who underwent surgical treatment in our department between July 2003 and December 2007 were retrospectively analyzed. All patients were divided into group without sympathetic symptoms (n = 284) and group with sympathetic symptoms (n = 34). The curvatures of both groups on cervical lateral radiographs were measured using Borden method and statistical analysis was performed.
The incidence of abnormal cervical curvature in group with cervical sympathetic symptoms were 67.6% (23/34), which was significantly higher than that in group without cervical sympathetic symptoms (50.7%, 144/284). Cervical curvature abnormality may be an independent factor that affects the cervical sympathetic symptoms.
In Zhonghua Wai Ke Za Zhi. 2008 Sep 15;46(18):1424-7, Treatment and mechanism of cervical spondylosis with sympathetic symptoms concluded: The sympathetic nerve fibers distributed in the cervical posterior longitudinal ligament maybe another one significant factor causing sympathetic symptom of cervical spondylosis.
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Association of tinnitus and electromagnetic hypersensitivity: hints for a shared pathophysiology?
From: PLoS ONE. 2009;4(3):e5026. Epub 2009 Mar 27
Tinnitus is a frequent condition with high morbidity and impairment in quality of life. The pathophysiology is still incompletely understood. Electromagnetic fields are discussed to be involved in the multi-factorial pathogenesis of tinnitus, but data proofing this relationship are very limited. Potential health hazards of electromagnetic fields have been under discussion for long. Especially, individuals claiming themselves to be electromagnetic hypersensitive suffer from a variety of unspecific symptoms, which they attribute to electromagnetic fields exposure. The aim of the study was to elucidate the relationship between electromagnetic field exposure, electromagnetic hypersensitivity and tinnitus using a case-control design.
Tinnitus, the perception of sound in the absence of an external sound, is a frequent disorder of auditory perception, which is very difficult to treat. Tinnitus as a phantom perception of a meaningless sound has to be differentiated from auditory hallucinations which mainly occur in the context of psychiatric diseases and are characterized by e.g. the perception of voices. About 10–20% of the adult population experiences some degree of tinnitus. Many learn to ignore the sounds and experience no major effects, but for about 1 in 100 adults, the noise interferes significantly with daily life. In those patients, tinnitus is frequently associated with neuropsychiatric co-morbidity such as depression, anxiety or sleep disorders, which underlines the clinical and socio-economic importance.
Even if the pathophysiology of tinnitus remains incompletely understood, there is growing evidence that dysfunctional neuroplastic processes in the brain are involved. In particular, it is assumed that tinnitus might be the correlate of maladaptive neuroplastic changes due to distorted sensory input. Accordingly functional imaging studies demonstrated neuroplastic alterations in the central auditory system. However tinnitus related alterations of neural functioning are not limited to the central auditory system, but also encompass non-auditory regions such as frontal and limbic areas.
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Abnormal resting-state cortical coupling in chronic tinnitus
From: BMC Neurosci. 2009 Feb 19;10(1):11. [Epub ahead of print]
Patients that suffer from chronic tinnitus complain of an ongoing perception of a phantom sound in the absence of any physical source for it. About 5-15 % of the population in western societies experience a phantom tinnitus sound and 1-3% of the population suffer from severe tinnitus that affects their daily life and is accompanied in 50 % of the cases by depression, in 40 % of the cases by insomnia and about 20% of the patients complain of an important decrease in their quality of life. Unfortunately, the underlying mechanisms responsible for the tinnitus perception is currently not known. Tinnitus therapies typically concentrate on coping with the tinnitus but there is no therapy that reliably reduces the perception of tinnitus.
Tinnitus is often accompanied by damage to the peripheral hearing system and a series of plastic changes in the central auditory system are observed in parallel to that. It is thought that a deafferentation of the hearing system triggers a series of reorganization processes at all levels of the auditory system. Indeed, abnormal neuronal activity in tinnitus has been demonstrated for the auditory nerve fibers, the dorsal cochlear nucleus, the inferior colliculus, the primary and the secondary auditory cortex. Furthermore, it has been found that a dissection of the auditory nerve in tinnitus patients does not lead to relief in tinnitus and most of the patients still experience tinnitus after surgery. Thus, there is an agreement that the tinnitus phantom sound is generated in the central nervous system – most likely as a result of the reorganization that is going on in the auditory system after hearing loss.
However, there are also studies that demonstrated tinnitus-related cortical abnormalities outside the auditory system. Using methods as different as Positron Emission Tomography (PET), Voxel Based Morphometry (VBM) and Magnetoencephalography (MEG) differences in cortical activity have been shown for the frontal cortex, the parietal lobe, mesial posterior regions and the subcollosal region including the nucleus accumbens. As hypothesized earlier by Jastreboff it might be that tinnitus is generated within the auditory system while non-auditory regions are involved in encoding the conscious percept well as the emotional evaluation of it. This idea also fits with a recently established model of the global neuronal workspace by Deheane and colleagues. This group suggests the existence of workspace neurons that are located mainly in the parietal lobe, the frontal, the cingulate cortex and the sensory systems. In order to form a conscious percept of a stimulus, two conditions are required: First, neuronal activity of the sensory cortex of the respective modality. Second, an entry into the global neuronal workspace and thus long-range coupling between the widely distributed workspace neurons. According to this model, coupling within this frontoparietal-cingulate network is needed for conscious perception (i.e. awareness of the stimulus). Activity of the sensory areas without this coupling would remain preconscious.
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Whiplash injuries can be visible by functional magnetic resonance imaging
From: Pain Res Manag. 2006 Autumn;11(3):197-9
Whiplash trauma can result in injuries that are difficult to diagnose. Diagnosis is particularly difficult in injuries to the upper segments of the cervical spine (craniocervical joint complex). Studies indicate that neck injuries in that region may be responsible for the cervicoencephalic syndrome, as evidenced by headache, balance problems, vertigo, dizziness, eye problems, tinnitus, poor concentration, sensitivity to light and pronounced fatigue. Consequently, diagnosis of lesions in the craniocervical joint region is important.
Functional magnetic resonance imaging is a radiological technique that can visualize injuries of the ligaments and the joint capsules, and accompanying pathological movement patterns. Three severely injured patients that had been extensively examined without any findings of structural lesions were diagnosed by functional magnetic resonance imaging to have injuries in the craniocervical joint region. These injuries were confirmed at surgery, and after surgical stabilization the medical condition was highly improved. It is important to draw attention to the urgent need to diagnose lesions and dysfunction in the craniocervical joint complex and also improve diagnostic methods in whiplash injuires.
