Differentiating comorbidities and predicting prognosis in idiopathic normal pressure hydrocephalus using cerebrospinal fluid biomarkers: a review

Idiopathic normal pressure hydrocephalus (iNPH) is a condition resulting from impaired cerebrospinal fluid (CSF) absorption and excretion characterized by a triad of symptoms comprising dementia, gait disturbance (impaired trunk balance), and urinary incontinence. CSF biomarkers not only assist in diagnosis but are also important for analyzing the pathology and understanding appropriate treatment indications. As the neuropathological findings characteristic of iNPH have yet to be defined, there remains no method to diagnose iNPH with 100% sensitivity and specificity. Neurotoxic proteins are assumed to be involved in the neurological symptoms of iNPH, particularly the appearance of cognitive impairment. The symptoms of iNPH can be reversed by improving CSF turnover through shunting. However, early diagnosis is essential as once neurodegeneration has progressed, pathological changes become irreversible and symptom improvement is minimal, even after shunting. Combining a variety of diagnostic methods may lead to a more definitive diagnosis and accurate prediction of the prognosis following shunt treatment. Identifying comorbidities in iNPH using CSF biomarkers does not contraindicate shunting-based intervention, but does limit the improvement in symptoms it yields, and provides vital information for predicting post-treatment prognosi

Effects of Dopamine Receptor Blockade on Cerebral Blood Flow Response to Somatosensory Stimulation in the Unanesthetized Rat

ABSTRACT Local cerebral blood flow (CBF) was determined in 30 cerebral structures, including four structures of the whisker-to-barrel cortex sensory pathway, by the quantitative autoradiographic [ 14 C]iodoantipyrine method during unilateral vibrissal stimulation in rats administered 0.1 or 1.0 mg/kg haloperidol or its control vehicle intravenously. The low dose of haloperidol had no significant effects on resting CBF or its enhancement by vibrissal stimulation. By standard t tests, the high dose statistically significantly lowered baseline CBF in frontal and visual cortex, hippocampus, dentate gyrus, inferior olive, cerebellar cortex, and the ventral posteromedial (VPM) thalamic nucleus on the unstimulated side, and raised baseline CBF in the lateral habenula; however, these changes lost statistical significance after Bonferroni correction for multiple comparisons. Neither dose had any effects on the increases in CBF evoked by vibrissal stimulation in the principal sensory trigeminal nucleus and barrel cortex, but the higher dose statistically significantly enhanced the percent increases in CBF due to the sensory stimulation in the spinal trigeminal nucleus and VPM thalamic nucleus. These results do not support a role for direct dopaminergic vasoactive mechanisms in the increases in CBF associated with neuronal functional activation

Lumboperitoneal shunt using fluoroscopy and a peel-away sheath

Background: After placement of the spinal catheter into the spinal canal during lumboperitoneal shunt (LPS) placement, the spinal catheter needs to be connected to the programmable valve. Although surgeons always try to secure the spinal catheter position during procedures, it may be accidentally pulled and displaced. This article aimed to introduce a “one-piece method” of LPS using fluoroscopy and peel-away sheath without connecting the spinal catheter to the programmable valve. Methods: An abdominal shunt catheter, valve, and spinal shunt catheter were connected and tunneled to the back for insertion into the lumbar spinal subarachnoid space. The spinal catheter was cut to a length of 15 cm. Lumbar puncture was performed using a 14-gauge Tuohy needle inserted at the L2-3 intervertebral space using an image-guided paramedian technique, and a 0.035-inch guidewire was passed gently through the Tuohy needle under fluoroscopic guidance. The Tuohy needle was withdrawn, and a 5-Fr peel-away sheath was advanced over the wire. The dilator and guide wire were removed, the distal end of the 5-Fr peel-away sheath was checked to ensure that the cerebrospinal fluid flowed out, and the spinal shunt catheter was passed down the sheath. After confirming under fluoroscopic guidance that the catheter was properly positioned, the peel-away sheath was removed. Results: LPS was performed using this method in seven patients without complications. Conclusion: This simple “one-piece method” using fluoroscopy and peel-away sheath is safe and effective for positioning the spinal catheter

Unilateral C1 Posterior Arch Screw-C2 Laminar Screw Posterior Fixation for Vertebral Artery Preservation in Bow Hunter’s Syndrome

Pedicle or lateral mass screws, which are usually used to fix atlantoaxial instability, increase the risk of vertebral artery (VA) injury in patients with bone or arterial anomalies or osteoporotic bone. Here, we report the use of a unilateral C1 posterior arch screw-C2 laminar screw posterior fixation with a contralateral C1 lateral mass screw for VA preservation in a patient with bow hunter’s syndrome (BHS). A 65-year-old male presented with recurrent loss of consciousness in the right rotational and backward-bending head positions for 1 year. Cerebral angiography in the same head position showed that the left VA was disrupted at C1/2 and the right VA was hypoplastic. The patient was diagnosed with BHS. C1-2 posterior fixation and iliac bone grafting were performed. The left VA was on the dominant side, and the VA was in a high position; thus, a C1 posterior arch screw was selected for the left side, a C1 lateral mass screw was selected for the right side, and a C2 laminar screw with O-arm navigation and a C-arm was used to prevent arterial injury. Intraoperative findings revealed no VA injury, and postoperative computed tomography showed the screw at the planned site. In a patient with BHS, posterior fixation with a unilateral C1 posterior arch screw-C2 laminar screw prevented VA injury because the screw could be inserted while avoiding the VA