Periventricular White Matter Abnormalities on Diffusion Tensor Imaging of Postural Instability Gait Disorder Parkinsonism

BACKGROUND AND PURPOSE

Postural instability gait disorder is a motor subtype of Parkinson disease associated with predominant gait dysfunction. We investigated the periventricular white matter comprising longitudinal, thalamic, and callosal fibers using diffusion tensor MR Imaging and examined clinical correlates in a cohort of patients with Parkinson disease and postural instability gait disorder and healthy controls.

MATERIALS AND METHODS

All subjects underwent the Tinetti Gait and Balance Assessment and brain MR imaging. The DTI indices (fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity) from ROIs dropped over the superior and inferior longitudinal fasciculi, inferior fronto-occipital fasciculus, anterior thalamic radiation, anterior and posterior limbs of the internal capsule, and the genu and body of corpus callosum were evaluated.

RESULTS

Our findings showed that the superior longitudinal fasciculus, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, anterior thalamic radiation, genu of the corpus callosum, and body of the corpus callosum are more affected in postural instability gait disorder than in those with Parkinson disease or healthy controls, with more group differences among the longitudinal fibers. Only the callosal fibers differentiated the postural instability gait disorder and Parkinson disease groups. DTI measures in the superior longitudinal fasciculus, frontostriatal fibers (anterior thalamic radiation, anterior limb of the internal capsule), and genu of the corpus callosum fibers correlated with clinical gait severity.

CONCLUSIONS

Findings from this case-control cohort lend further evidence to the role of extranigral pathology and, specifically, the periventricular fibers in the pathophysiology of postural instability gait disorder.

Neurosurgical history: Comparing the management of penetrating head injury in 1969 with 2005

Penetrating head trauma may present challenging problems in the acute phase (removal of foreign bodies, control of haemorrhage, prevention of infection) and in the management of long-term sequelae (neurological deficit, cognitive impairment, seizures). Two unusual cases demonstrate the progress made in emergency medicine, radiology neurointensive care, and neurosurgical head injury management over 36 years.

In vitro biopsy of colorectal carcinomas

OBJECTIVE

To determine the best part of an ulcerated colorectal neoplasm from which to take a biopsy in order to prove that the lesion is invasive.

PATIENTS AND METHODS

In this experimental study, biopsies were obtained from 50 ulcerated colorectal tumours using colonoscopic biopsy forceps on the resected specimen after major colorectal resections. Four biopsy sites were chosen, the junction between the normal mucosa and the rolled edge, the top of the rolled edge, the junction between the rolled edge and the ulcer base, and the centre of the ulcer. A code was used so that the pathologist was not aware of the site of each biopsy.

RESULTS

Biopsies from the very edge of the lesion were positive for carcinoma in 16% of cases, from the top of the roll in 64%, from the inner aspect of the roll in 88% and from the centre of the ulcer in 90%.

CONCLUSION

Biopsies from ulcerated colorectal carcinomas are more likely to be positive if taken from the centre of the lesion, rather than the very edge.