Final common pathway for tinnitus: theoretical and clinical implications of neuroanatomical substrates.

A final common pathway (FCP) for tinnitus has been hypothesized since 1989 for all clinical types of tinnitus, particularly subjective idiopathic tinnitus (SIT) of the severe disabling type. This was intended to explain the transformation-transition of the sensation of an aberrant auditory sensation-tinnitus (i.e.

Fluid dynamics vascular theory of brain and inner-ear function in traumatic brain injury: a translational hypothesis for diagnosis and treatment.

It is hypothesized that in all traumatic brain injury (TBI) patients with a clinical history of closed or penetrating head injury, the initial head trauma is associated with a vibratory sensation and noise exposure, with resultant alteration in vascular supply to the structures and contents of the fluid compartments of brain and ear (i.e., the fluid dynamics vascular theory of brain-inner-ear function [FDVTBE]).

Central nervous system neurodegeneration and tinnitus: a clinical experience. Part II: translational neurovascular theory of neurodegenerative CNS disease and tinnitus.

The translation of a neurovascular hypothesis for Alzheimer's disease to subjective idiopathic tinnitus (SIT) is presented as a challenge to the predominantly sensorineural view of SIT and its clinical application for tinnitus treatment. The concept of neurovascular dysfunction and neurodegeneration (ND) in SIT patients has been proposed and reported as an etiology in a particular subset of tinnitus patients with a diagnosis of medical-audiological tinnitus, through a medical-audiological tinnitus patient protocol, to be a predominantly central-type, severe, disabling SIT (n = 54 of 96). A medical-audiological ND tinnitus profile was the basis for selection of 18 SIT patients (n = 18 of 54) for nuclear medicine brain imaging (i.

Central nervous system neurodegeneration and tinnitus: a clinical experience. Part I: Diagnosis.

In an evolving clinical experience since 1979, the medical significance of the symptom of tinnitus has been identified as a "soft" sign of neurodegeneration (ND) in the central nervous system (CNS) in a particular subset of tinnitus patients diagnosed with a predominantly central-type, severe, disabling, subjective idiopathic tinnitus. To highlight this experience, a retrospective review and analysis of consecutive tinnitus patients (N = 96) was conducted. Ninety-six tinnitus patients (ages 22-90 years) were seen in neurotological consultation from November 1, 2005, to June 30, 2007, all of whom had subjective idiopathic tinnitus of the severe disabling type (SIT).

Congenital atresia of the external ear and tinnitus: a new syndrome.

Congenital atresia of the external ears and severe tinnitus has been reported by two patients to be contralateral to the atretic ear. The use of the nuclear medicine imaging technique of single-photon emission computed tomography (SPECT) of brain has demonstrated hypoperfusion in brain areas supplied by the middle cerebral artery on the side of the atretic ear. Ultrahigh-frequency audiometry (UHFA) has revealed a bilateral loss of hearing greater than expected for the age of affected patients.

Ultra-high-frequency acoustic stimulation and tinnitus control: a positron emission tomography study.

Ultra-high-frequency (UHF) external acoustic stimulation with the UltraQuiet device (UQ) has been reported to provide significant relief of severe disabling-type tinnitus. The nuclear medicine imaging technique of positron emission tomography (PET) was selected as a monitoring system to compare objectively metabolic alterations in brain function before and after UHF/UQ and to correlate the PET data with the subjective behavioral response of patients reporting tinnitus relief. PET of brain was completed on 6 patients randomly selected from a cohort of 15 patients included in a protocol to establish long-term tinnitus relief with UHF/UQ.

Benzodiazepine receptor distribution in severe intractable tinnitus.

Tinnitus affects nearly 50 million people in the United States, with a minority demonstrating marked functional impairment. Alterations of gamma aminobutyric acid (GABA) neuronal function and benzodiazepine receptor (BZR) function in particular have been implicated in the pathophysiology of severe, chronic tinnitus. The purpose of our study was to evaluate the distribution of BZR in the brain using 123I-iomazenil single-photon emission computed tomography (SPECT) imaging in patients with severe, intractable central tinnitus.

GABAA-benzodiazepine-chloride receptor-targeted therapy for tinnitus control: preliminary report.

Our goal was to attempt to establish neuropharmacological tinnitus control (i.e., relief) with medication directed to restoration of a deficiency in the gamma-aminobutyric acid-benzodiazepine-chloride receptor in tinnitus patients with a diagnosis of a predominantly central type tinnitus.

Benzodiazepine receptor deficiency and tinnitus.

As regards the symptom of a predominantly central tinnitus of the severe, disabling type, it has been hypothesized that a deficiency in the benzodiazepine receptor exists in the medial temporal lobe system of brain and is directly related to affect impairments including anxiety, stress, depression, and fear. This hypothesis has been investigated with single-photon emission computed tomography using the benzodiazepine radioligand 123I Iomazenil. Visual analysis revealed preliminary results of diminished benzodiazepine-binding sites in the medial temporal cortex of all patients with severe tinnitus (N = 6), a finding that is consistent with the hypothesis implicating GABAergic mechanisms in the pathophysiology of the disorder.

Descending auditory system/cerebellum/tinnitus.

The cerebellum and the descending auditory system (DAS) are considered clinically significant for influencing the development of the clinical course of tinnitus of the severe disabling type. It is hypothesized that the SPECT of Brain perfusion asymmetries in cerebellum, demonstrated since 1993, reflect clinically the influence of an aberrant auditory stimulus i.e.

Tc-99m MAG3 evaluation of recipients with dual adult cadaveric renal allografts. Simultaneous transplantation of both kidneys from marginal donors.

Purpose: The application of Tc-99m mercaptoacetyl triglycine (MAG3) renal scintigraphy in patients who had simultaneous unilateral retroperitoneal transplant of both kidneys from marginal adult cadaveric donors is assessed.

Methods: Eighteen patients who had this unusual form of kidney transplant were monitored and evaluated by Tc-99m MAG3 renal scintigraphy. More than 60 of the radioisotopic studies, including immediate postoperative and subsequent follow-up examinations, were performed among these patients.

Scintigraphic demonstration of postural induced drainage stasis in an en bloc renal allograft.

Within 6 months after an en bloc transplantation of two kidneys from a cadaveric pediatric donor, the recipient was referred for further scintigraphic evaluation because of clinical suspicion of having a postural related function impairment of the grafted kidneys. Tc-99m MAG3 imaging, modified by varying the position of the patient during the procedure, resulted in detection of drainage stasis only with the patient standing. This drainage stasis had not been appreciated in the preceding routine examinations performed with the patient supine.

Sestamibi scan for preoperative localization in primary hyperparathyroidism.

Background: Various invasive and noninvasive localizing tests are available for the evaluation of primary hyperparathyroidism. The surgical success in primary intervention exceeds 90% without localization studies. However, localization tests are absolutely essential for re-exploration and in certain select circumstances, even in primary exploration.

Penile scintigraphy for priapism in sickle cell disease.

Unlabelled: Penile scintigraphy with [99mTc]pertechnetate/99mTc-RBCs was performed in patients with sickle cell disease patients who had priapism to assess the role of this imaging procedure in directing the clinical management of these patients.

Methods: Fifteen studies were performed in 13 patients who were treated according to a protocol not dependent on the imaging results. The scintigraphic findings of penile vascular perfusion (stagnant or nonstagnant patterns) were collated retrospectively with the form of treatment needed for relief of the condition.

SPECT Imaging of Brain and Tinnitus-Neurotologic/Neurologic Implications.

Single Photon Emission Computed Tomography (SPECT) of brain with technetium-99m hexamethyl propyleneamine oxine (Tc-HMPAO) is an imaging technique which has been introduced for the identification of abnormalities of regional cerebral blood flow (rCBF) in patients with a central type of subjective idiopathic tinnitus, which was characterized as severe and disabling. These patients demonstrate a negative clinical history, physical examination does not evidence central nervous system disease, and CT/MRI studies of brain were negative. Two typical cases are presented which demonstrate significant regional abnormalities in cerebral perfusion bilateral of temporal, frontal, parietal and hippocampal amygdala regions when compared with normative Tc-HMPAO SPECT of brain data.

Pitfalls and limitations of diuretic renography.

We report five pediatric cases that illustrate the methodologic pitfalls and limitations of diuretic renography in suspected ureteropelvic junction obstruction. False-positive studies may be related to such avoidable flaws in methodology as premature diuretic administration, inadequate diuretic dose, and bladder distension, or to recent pyeloplasty. False-negative results may occur despite optimum technique, necessitating a follow-up study for confirmation.

Alternating hemiplegia of childhood: studies of regional cerebral blood flow using 99mTc-hexamethylpropylene amine oxime single-photon emission computed tomography.

Alternating hemiplegia of childhood is a rare disorder of unknown cause associated with progressive neurological deterioration. We report the results of regional cerebral blood flow studies using 99mTc-hexamethylpropylene amine oxime single-photon emission computed tomography in 3 patients. These studies were performed during the hemiplegic attacks (n = 6) and during the symptom-free periods (n = 2).

Reversible increased technetium-99m-HMPAO cerebral cortical activity: a scintigraphic reflection of luxuriant hyperperfusion.

A hemiparetic and aphasic patient, 3 days after acute traumatic transection of the left internal carotid artery requiring life-saving total embolic occlusion, revealed ipsilateral increased peripheral hemispheric 99mTc-HMPAO activity. Ten days postocclusion, HMPAO peripheral cortical flow normalized as hemiparesis and aphasia significantly cleared. The initial lateralized HMPAO hyperactivity pattern may reflect reactive hyperemia, a sign previously identified by contrast angiography and often associated with a better prognosis in evolving CVA.