[P2-173] Morphometric analysis of upper brainstem on MRI in Rett syndrome
Introduction: Rett syndrome (RTT) is characterized with hand-wringing movements, autistic behavior, intellectual disability and sleep pattern disturbance. Since the development of brainstem monoaminergic neuron system in early childhood may be a key factor in the pathology of RTT, we performed morphometric analysis in brain MRI, in early childhood.
Methodology: We analyzed 11 sagittal images on brain MRI obtained from 9 patients with RTT, who visited our clinic and 48 age-matched controls. We divided the upper brainstem into the following four regions, a. tegmentum mesencephalic, b. tectum mesencephalic, c. basis pontis and d. tegmentum pontis. We measured the area of each region and calculated the ratio of each region against the entire area of upper brainstem. Statistical analysis was done by Mann-Whitney test.
Results: Mean age in controls and patients with RTT were 31.0±16.0 months and 30.6±15.9 months, respectively. The area of each region and the ratio of each region against the entire upper brainstem were a. 0.862±0.141cm2 and 21.00±1.39%, b. 0.288±0.058 cm2 and 7.00±0.86%, c. 1.941±0.247 cm2 and 45.23±3.02% and d. 1.014±0.155 cm2 and 24.49±2.58%, respectively. The ratios of a. and c. were narrowed in the RTT group when we compared with those in the control group (p<0.01).
Conclusion: The pedunculopontine nucleus (PPN) exists in the midbrain. Some researchers have speculated the possible involvement of lesions in the PPN in the pathophysiology of RTT. It is likely that the narrowing of the mesencephalic tegmentum on MRI in the patients with RTT may reflect the morphological changes in the PPN.
Methodology: We analyzed 11 sagittal images on brain MRI obtained from 9 patients with RTT, who visited our clinic and 48 age-matched controls. We divided the upper brainstem into the following four regions, a. tegmentum mesencephalic, b. tectum mesencephalic, c. basis pontis and d. tegmentum pontis. We measured the area of each region and calculated the ratio of each region against the entire area of upper brainstem. Statistical analysis was done by Mann-Whitney test.
Results: Mean age in controls and patients with RTT were 31.0±16.0 months and 30.6±15.9 months, respectively. The area of each region and the ratio of each region against the entire upper brainstem were a. 0.862±0.141cm2 and 21.00±1.39%, b. 0.288±0.058 cm2 and 7.00±0.86%, c. 1.941±0.247 cm2 and 45.23±3.02% and d. 1.014±0.155 cm2 and 24.49±2.58%, respectively. The ratios of a. and c. were narrowed in the RTT group when we compared with those in the control group (p<0.01).
Conclusion: The pedunculopontine nucleus (PPN) exists in the midbrain. Some researchers have speculated the possible involvement of lesions in the PPN in the pathophysiology of RTT. It is likely that the narrowing of the mesencephalic tegmentum on MRI in the patients with RTT may reflect the morphological changes in the PPN.