Higher prevalence of idiopathic normal pressure hydrocephalus-like MRI features in progressive supranuclear palsy: An imaging reminder of atypical parkinsonism.

OBJECTIVES: The classic triad of idiopathic normal pressure hydrocephalus (NPH) encompass gait disturbance, cognitive impairment, and urinary incontinence. These symptoms overlap with parkinsonism but with distinct treatment. Lacking applicable differentiation also hampers the prediction to therapeutic response. Here, we try to clarify this issue among different Parkinsonian syndromes and propose some innovative thinking while approaching a patient with parkinsonism and hydrocephalus concomitantly. METHODS: Twenty-four patients with clinical probable multiple system atrophy (MSA), 34 with probable progressive supranuclear palsy (PSP), and 58 with sex- and age-matched Parkinson's disease (PD) were enrolled. Evans' index (EI), callosal angle (CA), antero-posterior (AP) diameter of the midbrain, length of the midbrain tegmentum diameter (MBTegm ), and disproportionately enlarged subarachnoid space hydrocephalus (DESH) were evaluated using the conventional MRI. Logistic regression was applied to identify the independent variables in hydrocephalus. RESULTS: Patients with PSP had higher mean EI than those with MSA and PD. Around 38.2% of patients with PSP had accompanied hydrocephalus (EI > 0.3). Parkinsonism subtypes (PD, MSA, or PSP), AP diameter of the midbrain, and MBTegm were significantly different among patients with and without hydrocephalus. After regression analysis, parkinsonism subtype stood out to be the most key risk factor of hydrocephalus. The comparison between patients with PSP with and without hydrocephalus did not disclose specific clinical characteristics or risk factors. CONCLUSIONS: This study demonstrates that the presence of NPH-like MRI features is much higher in PSP patients, and this tendency is decided upon the determination of parkinsonism subtype. Sharing pathophysiological characteristics in these two diseases is implied. More diagnostic tools are needed to better differentiate the two diseases and decide the treatment. To closely observe hydrocephalic parkinsonism patients and well inform the possible limited shunting benefits if PSP core features appear, will be more pivotal and practical at present clinical practice.

Anti-neuroinflammation ameliorates systemic inflammation-induced mitochondrial DNA impairment in the nucleus of the solitary tract and cardiovascular reflex dysfunction.

BACKGROUND: Decreased heart rate variability (HRV) leads to cardiovascular diseases and increased mortality in clinical studies. However, the underlying mechanisms are still inconclusive. Systemic inflammation-induced neuroinflammation is known to impair the autonomic center of cardiovascular regulation. The dynamic stability of blood pressure and heart rate (HR) is regulated by modulation of the reciprocal responses of sympathetic and parasympathetic tone by the baroreflex, which is controlled by the nucleus of the solitary tract (NTS). METHODS: Systemic inflammation was induced by E. coli lipopolysaccharide (LPS, 1.2 mg/kg/day, 7 days) peritoneal infusion via an osmotic minipump in normotensive Sprague-Dawley rats. Systolic blood pressure (SBP) and HR were measured by femoral artery cannulation and recorded on a polygraph under anesthesia. The low-frequency (LF; 0.25-0.8 Hz) and high-frequency (HF; 0.8-2.4 Hz) components of SBP were adopted as the indices for sympathetic vasomotor tone and parasympathetic vasomotor tone, while the baroreflex effectiveness index (BEI) was adopted from the analysis of SBP and pulse interval (PI). The plasma levels of proinflammatory cytokines and mitochondrial DNA (mtDNA) oxidative damage were analyzed by ELISA. Protein expression was evaluated by Western blot. The distribution of oxidative mtDNA was probed by immunofluorescence. Pharmacological agents were delivered via infusion into the cisterna magna with an osmotic minipump. RESULTS: The suppression of baroreflex sensitivity was concurrent with increased SBP and decreased HR. Neuroinflammatory factors, including TNF-α, CD11b, and Iba-1, were detected in the NTS of the LPS group. Moreover, indices of mtDNA damage, including 8-OHdG and γ-H2AX, were significantly increased in neuronal mitochondria. Pentoxifylline or minocycline intracisternal (IC) infusion effectively prevented mtDNA damage, suggesting that cytokine and microglial activation contributed to mtDNA damage. Synchronically, baroreflex sensitivity was effectively protected, and the elevated blood pressure was significantly relieved. In addition, the mtDNA repair mechanism was significantly enhanced by pentoxifylline or minocycline. CONCLUSION: These results suggest that neuronal mtDNA damage in the NTS induced by neuroinflammation could be the core factor in deteriorating baroreflex desensitization and subsequent cardiovascular dysfunction. Therefore, the enhancement of base excision repair (BER) signaling in mitochondria could be a potential therapeutic strategy for cardiovascular reflex dysregulation.

Pioglitazone reversed the fructose-programmed astrocytic glycolysis and oxidative phosphorylation of female rat offspring.

Excessive maternal high-fructose diet (HFD) during pregnancy and lactation has been reported to cause metabolic disorders in the offspring. Whether the infant's brain metabolism is disturbed by maternal HFD is largely unknown. Brain energy metabolism is elevated dramatically during fetal and postnatal development, whereby maternal nutrition is a key factor that determines cellular metabolism. Astrocytes, a nonneuronal cell type in the brain, are considered to support the high-energy demands of neurons by supplying lactate. In this study, the effects of maternal HFD on astrocytic glucose metabolism were investigated using hippocampal primary cultures of female infants. We found that glycolytic capacity and mitochondrial respiration and electron transport chain were suppressed by maternal HFD. Mitochondrial DNA copy number and mitochondrial transcription factor A expression were suppressed by maternal HFD. Western blots and immunofluorescent images further indicated that the glucose transporter 1 was downregulated whereas the insulin receptor-α, phospho-insulin receptor substrate-1 (Y612) and the p85 subunit of phosphatidylinositide 3-kinase were upregulated in the HFD group. Pioglitazone, which is known to increase astrocytic glucose metabolism, effectively reversed the suppressed glycolysis, and lactate release was restored. Moreover, pioglitazone also normalized oxidative phosphorylation with an increase of cytosolic ATP. Together, these results suggest that maternal HFD impairs astrocytic energy metabolic pathways that were reversed by pioglitazone.