Changes of pituitary gland volume in Kennedy disease.

BACKGROUND AND PURPOSE: Kennedy disease is a rare X-linked neurodegenerative disorder caused by a CAG repeat expansion in the first exon of the androgen-receptor gene. Apart from neurologic signs, this mutation can cause a partial androgen insensitivity syndrome with typical alterations of gonadotropic hormones produced by the pituitary gland. The aim of the present study was therefore to evaluate the impact of Kennedy disease on pituitary gland volume under the hypothesis that endocrinologic changes caused by partial androgen insensitivity may lead to morphologic changes (ie, hypertrophy) of the pituitary gland. MATERIALS AND METHODS: Pituitary gland volume was measured in sagittal sections of 3D T1-weighted 3T-MR imaging data of 8 patients with genetically proven Kennedy disease and compared with 16 healthy age-matched control subjects by use of Multitracer by a blinded, experienced radiologist. The results were analyzed by a univariant ANOVA with total brain volume as a covariant. Furthermore, correlation and linear regression analyses were performed for pituitary volume, patient age, disease duration, and CAG repeat expansion length. Intraobserver reliability was evaluated by means of the Pearson correlation coefficient. RESULTS: Pituitary volume was significantly larger in patients with Kennedy disease (636 [±90] mm(3)) than in healthy control subjects (534 [±91] mm(3)) (P = .041). There was no significant difference in total brain volume (P = .379). Control subjects showed a significant decrease in volume with age (r = -0.712, P = .002), whereas there was a trend to increasing gland volume in patients with Kennedy disease (r = 0.443, P = .272). Gland volume correlated with CAG repeat expansion length in patients (r = 0.630, P = .047). The correlation coefficient for intraobserver reliability was 0.94 (P < .001). CONCLUSIONS: Patients with Kennedy disease showed a significantly higher pituitary volume that correlated with the CAG repeat expansion length. This could reflect hypertrophy as the result of elevated gonadotropic hormone secretion caused by the androgen receptor mutation with partial androgen insensitivity.

Structural changes of central white matter tracts in Kennedy's disease - a diffusion tensor imaging and voxel-based morphometry study.

OBJECTIVES: Spinobulbar muscular atrophy [Kennedy's disease (KD)] is a rare X-linked neurodegenerative disorder of mainly spinal and bulbar motoneurons. Recent studies suggest a multisystem character of this disease. The aim of this study was to identify and characterize structural changes of gray (GM) and white matter (WM) in the central nervous system. MATERIAL AND METHODS: Whole-brain-based voxel-based morphometry (VBM) and diffusion tensor imaging (DTI) analyses were applied to MRI data of eight genetically proven patients with KD and compared with 16 healthy age-matched controls. RESULTS: Diffusion tensor imaging analysis showed not only decreased fractional anisotropy (FA) values in the brainstem, but also widespread changes in central WM tracts, whereas VBM analysis of the WM showed alterations primarily in the brainstem and cerebellum. There were no changes in GM volume. The FA value decrease in the brainstem correlated with the disease duration. CONCLUSION: Diffusion tensor imaging analysis revealed subtle changes of central WM tract integrity, while GM and WM volume remained unaffected. In our patient sample, KD had more extended effects than previously reported. These changes could either be attributed primarily to neurodegeneration or reflect secondary plastic changes due to atrophy of lower motor neurons and reorganization of cortical structures.

Assessment of aspiration risk in acute ischaemic stroke--evaluation of the simple swallowing provocation test.

BACKGROUND: Aspiration is a common complication in acute stroke patients and is strongly associated with a poor outcome. Due to an insufficient sensitivity and specificity of clinical bedside tests, further refinements are needed to improve the accuracy of clinical aspiration screening in acute stroke. OBJECTIVE: To assess the ability of the simple 2-step swallowing provocation test (SPT) to detect aspiration risk in acute stroke patients. METHODS: 100 consecutive patients with first-ever stroke were examined by SPT and fiberoptic endoscopic evaluation of swallowing (FEES) within 72 hours of stroke onset. Using FEES as an objective instrumental technique to evaluate dysphagia, statistical measures representing the ability of SPT to detect aspiration risk were calculated. RESULTS: The incidence of endoscopically proven aspiration risk was 81%. The 1st-step SPT had a sensitivity of 74.1% and a specificity of 100%. Although the 2nd-step SPT showed the same 100% specificity, sensitivity was significantly lower. False-negative results of SPT appeared predominantly in subjects exhibiting leakage of liquids to pyriform sinus without a pronounced delay in swallow onset. CONCLUSIONS: In acute stroke patients with an impairment of the pharyngeal phase of swallowing, 1st-step SPT reliably detects aspiration risk. In patients with a sole or predominant impairment of the oral phase of swallowing and a relatively intact pharyngeal phase, SPT fails to detect aspiration risk sufficiently. In the latter group, FEES or additional clinical features more specifically indicating oral-phase pathology should be considered to accurately judge the patient's aspiration risk.

No indication of brain reorganization after unilateral ischemic lesions of the auditory cortex.

We used magnetoencephalography to study contralesional auditory reorganization in three men with chronic unilateral ischemic lesions of the auditory cortex. Although no response was found over the lesioned hemisphere, processing in the unaffected hemisphere was indistinguishable vs healthy controls. In contrast to sensorimotor and language systems, the auditory system seems to lack contralateral reorganization, presumably because patients are typically not aware of hearing deficits and thus do not perform training.