Pituitary morphovolumetric changes in Alström syndrome.

PURPOSE: Alström syndrome (AS) is a rare monogenic ciliopathy characterized by cone-code dystrophy, leading to early blindness, and obesity. Early endocrinological dysfunctions, especially growth hormone deficiency and hypogonadism, are detected in about half of AS patients. This MRI study investigates the presence of pituitary gland abnormalities in a large cohort of AS patients. METHODS: Pituitary morphological changes (gland flattening with partial or total empty sella) were evaluated on midsagittal high-resolution T1-weighted images of 32 AS patients (mean-age 23.2±9.4 years; range: 6-45, 15 females) and 21 unrelated healthy subjects (mean age 23.2±11.2 years; range: 6-43; 10 females). RESULTS: Among AS patients, 11/32 (34%) had total empty sella and 6/32 (19%) partial empty sella, while 3/21 (14%) of controls had partial empty sella and none presented with total empty sella (P<0.005). AS patients harboring a total or partial empty sella did not differ from those with normal pituitary gland for gender (P=0.98), BMI (P=0.10) or visual impairment (P=0.21), while the presence of empty sella was associated with an older age (P=0.007) being especially frequent above the age of 30. CONCLUSIONS: Total or partial empty sella appears commonly during the course of AS. Pituitary gland flattening might represent the morphological underpinning of subtle endocrinologic dysfunctions and raises the need to further investigate the pituitary function in this rare ciliopathy.

Morphometric correlates of dysarthric deficit in amyotrophic lateral sclerosis.

Our objective was to investigate the volumetric correlates of speech in amyotrophic lateral sclerosis (ALS). Twenty-three ALS patients had a structural 3D MRI scan, neuropsychological, linguistic and speech assessments. Twenty-three healthy adults of comparable age, education, white-matter hyperintensity load and intracranial volumes were also recruited. Between-group differences in grey matter and white matter (WM) were examined to characterize ALS patients accurately. The association between residual speech and volumetric maps was studied in these patients. Results demonstrated that ALS patients showed a pattern of WM reduction, which was located in peri-cortical motor/premotor fibres bilaterally, and in a large volume extending from the pons/midbrain to the cerebellum. A speech composite score was computed, and this was positively associated with premotor/supplementary-motor WM bilaterally, and right cerebellar WM. Since premotor associations were found in volumes where ALS patients showed WM reduction, this region is believed to be directly involved in speech execution in this group. Since cerebellar associations were instead found in volumes free from shrinkage, this region is interpreted as playing a modulatory role, compensating for the impact of ALS pathology.