Subcortical microstructural diffusion changes correlate with gait impairment in Parkinson's disease.

BACKGROUND: Gait impairments are common in Parkinson's Disease (PD) and are likely caused by degeneration in multiple brain circuits, including the basal ganglia, thalamus and mesencephalic locomotion centers (MLC). Diffusion tensor imaging (DTI) assesses fractional anisotropy (FA) and mean diffusivity (MD) that reflect the integrity of neuronal microstructure. We hypothesized that DTI changes in motor circuits correlate with gait changes in PD. OBJECTIVE: We aimed to identify microstructural changes of brain locomotion control centers in PD via DTI and their correlations with clinical and quantitative measures of gait. METHODS: Twenty-one PD patients reporting gait impairment and 15 controls were recruited. Quantitative gait and clinical tests were recorded in PD subjects' medication ON and OFF states. Region of Interest (ROI) analysis of the thalamus, basal ganglia and MLC was performed using ExploreDTI. Correlations between FA/MD with clinical gait parameters were examined. RESULTS: Microstructural changes were seen in the thalamus, caudate and MLC in the PD compared to the control group. Thalamic microstructural changes significantly correlated with gait parameters in the pace domain including the Timed Up and Go in the ON state. Caudate changes correlated with cadence and stride time in the OFF state. CONCLUSIONS: Our pilot study suggests that PD is associated with a characteristic regional pattern of microstructural degradation in the thalamus, caudate and MLC. The DTI changes may represent subcortical locomotion network failure. Overall, DTI ROI analyses might provide a useful tool for assessing PD for functional status and specific motor domains, such as gait, and potentially could serve as an imaging marker.

Imaging appearance of myelopathy secondary to nitrous oxide abuse: a case report and review of the literature.

Purpose The abuse of nitrous oxide (N2O) can induce Vitamin B12 deficiency that subsequently leads to central nervous demyelination, myelopathy and peripheral neuropathy. Although myelopathy has been reported in the past, the specific locations and prognosis of the disease are still unclear. MATERIALS AND METHODS: We report the case of a 22-year-old male who presented with quadriplegia that began after a 3-month history of inhalation of N2O. We summarized the clinical data of this entity and performed a comprehensive literature review of various presentations and MRI features of myelopathy secondary to N2O abuse. RESULTS: In combination with previous reports of 14 cases, we found that the onset of the disease was usually subacute, and the majority of patients (92.85%) were young men. There was no definite relationship between myelopathy and the amount or duration of N2O inhalation. The most common clinical manifestation was sensory ataxia, and the cervical spinal cord was the most frequently impaired area of the whole spinal cord. The spinal cord lesions had a high signal intensity on T2-weighted MRI and usually involved more than three spinal segments and impaired the posterior column more significantly. Most patients recovered well after vitamin B12 supplementation. CONCLUSIONS: Myelopathy secondary to N2O abuse is generally seen in young men. The clinical diagnosis mainly depends on a history of N2O inhalation and the characteristic imaging changes in the posterior cervical spinal cord. Early diagnosis and intervention are important for a satisfactory prognosis.

Two new C13-norisoprenoids from Solanum lyratum.

Two new C(13)-norisoprenoids, named lyratols E and F (1-2), were isolated from the whole plant of Solanum lyratum Thunb, and their structures were elucidated by extensive spectroscopic analyses. In vitro, two new compounds were found to show significant cytotoxicity against selected cancer cells including P-388 and HT-29.

Neurologic complications of bariatric surgery.

With the rapid rise in the number of bariatric surgeries performed for morbid obesity, several short- and long-term neurologic complications of this procedure have been identified. These complications affect various levels of the neuraxis, and most are likely secondary to deficiency of essential minerals and vitamins. We report on 3 patients who developed unusual and severe neurologic deficits after undergoing bariatric surgery, including Wernicke encephalopathy, acute and rapidly progressive polyneuropathy, myelopathy, and visual deficits. Two developed clinical features of Parkinsonism, a complication not previously reported in this patient population. None of our patients had attended a nutrition clinic postoperatively. All 3 had a rapid weight loss and intractable vomiting preceding the development of neurologic symptoms, and all were found to have significant vitamin deficiencies. Replacement of vitamins resulted in a slow and variable degree of neurologic recovery. Patients undergoing bariatric surgery should have close monitoring of their nutritional status postoperatively. Routine supplementation of vitamins and minerals may be a cost-effective strategy for preventing neurologic complications in these patients.

Optimization of antioxidant activity by response surface methodology in hydrolysates of jellyfish (Rhopilema esculentum) umbrella collagen.

To optimize the hydrolysis conditions to prepare hydrolysates of jellyfish umbrella collagen with the highest hydroxyl radical scavenging activity, collagen extracted from jellyfish umbrella was hydrolyzed with trypsin, and response surface methodology (RSM) was applied. The optimum conditions obtained from experiments were pH 7.75, temperature (T) 48.77 degrees C, and enzyme-to-substrate ratio ([E]/[S]) 3.50%. The analysis of variance in RSM showed that pH and [E]/[S] were important factors that significantly affected the process (P<0.05 and P<0.01, respectively). The hydrolysates of jellyfish umbrella collagen were fractionated by high performance liquid chromatography (HPLC), and three fractions (HF-1>3000 Da, 1000 Da