Changes in postural stability after cerebrospinal fluid tap test in patients with idiopathic normal pressure hydrocephalus.

Introduction: In patients with idiopathic normal pressure hydrocephalus (iNPH), the characteristics of balance disturbance are not as well understood as those related to gait. This study examined changes in postural stability in quiet standing after the cerebrospinal fluid tap test (CSFTT) in these patients. Furthermore, the study explored the relationship between the amount of spontaneous body sway and both gait and executive function. Materials and methods: All patients diagnosed with iNPH underwent CSFTT. We evaluated their center of pressure (COP) measurements on a force plate during quiet standing, both pre- and post-CSFTT. Following the COP measurements, we calculated COP parameters using time and frequency domain analysis and assessed changes in these parameters after CSFTT. At pre-CSFTT, we assessed the Timed Up and Go (TUG) and the Frontal Assessment Battery (FAB). We investigated the relationship between COP parameters and the TUG and FAB scores at pre-CSFTT. Results: A total of 72 patients with iNPH were initially enrolled, and 56 patients who responded positively to CSFTT were finally included. Post-CSFTT, significant improvements were observed in COP parameters through time domain analysis. These included the velocity of COP (vCOP), root-mean-square of COP (rmsCOP), turn index, torque, and base of support (BOS), compared to the pre-CSFTT values (p < 0.05). In the frequency domain analysis of COP parameters post-CSFTT, there was a decrease in both the peak and average of power spectral density (PSD) values in both the anteroposterior (AP) and mediolateral (ML) directions below 0.5 Hz (p < 0.05). In addition, the TUG scores showed a positive correlation with vCOP, rmsCOP, turn index, torque, BOS, and both the peak and average PSD values in the AP and ML directions below 0.5 Hz (p < 0.05). The FAB scores demonstrated a negative correlation with vCOP, rmsCOP, turns index, BOS, and both peak and average PSD values in the AP direction below 0.5 Hz (p < 0.05). Conclusion: In patients with iNPH who responded to CSFTT, there was an improvement in spontaneous body sway during quiet standing after CSFTT. Increased spontaneous sway is associated with impaired gait and frontal lobe function. This may be linked to impaired cortico-cortical and cortico-subcortical circuits in patients with iNPH.

Combining Unilateral Biportal Endoscopic Surgery with Lumboperitoneal Shunt Surgery for Patients with Coexisting Normal-Pressure Hydrocephalus and Lumbar Spinal Stenosis: A Technical Note.

BACKGROUND: Normal-pressure hydrocephalus (NPH) is a condition characterized by an abnormal cerebrospinal fluid (CSF) homeostasis in the brain, resulting in cognitive decline, gait disturbances, and urinary incontinence. Globally, the frequency of NPH becomes has become a major clinical concern with an increase in the elderly population. A lumboperitoneal (LP) shunt surgery is one therapeutic intervention, which diverts CSF from the brain to the peritoneal cavity to mitigate NPH symptoms. However, LP shunt surgery can be precluded by lumbar spine degeneration. CASE DESCRIPTION: In cases of comorbidity involving NPH and lumbar spine degeneration, the combination of unilateral biportal endoscopic (UBE) surgery, which is a minimally invasive spinal procedure, and LP shunt surgery is a new alternative. Both spinal degeneration and NPH are concurrently addressed in this approach. A 70-year-old patient with NPH and severe lumbar stenosis successfully underwent the aforementioned combined surgery, with remarkable improvement in symptoms. CONCLUSIONS: While the result is promising, the efficacy of this method warrants validation by conducting larger studies. Nonetheless, combining UBE and LP shunt surgeries could redefine treatment for elderly patients with NPH and spinal stenosis.

Border Zone Maybe Correlated with Radiation Necrosis After Radiosurgery in Metastatic Brain Tumor.

BACKGROUND: Radiation necrosis (RN) after stereotactic radiosurgery (SRS) in brain metastases has been extensively evaluated, and RN is correlated with various risk factors. However, no study comprehensively analyzed the correlation between RN and the border zones of the brain that are vulnerable to ischemia. We hypothesized that patients with tumors in the border zone are at high risk of RN. Hence, the current study aimed to assess the correlation between border zone lesions and RN, with consideration of other predetermined factors. METHODS: This retrospective study included 117 patients with 290 lesions who underwent Gamma Knife SRS. Radiological and clinical analyses were performed to identify factors possibly correlated with RN. Notably, the lesion location was classified into 2 groups (border zone and nonborder zone) based on the blood supply. RESULTS: In total, 22 (18.8%) patients with 22 (7.5%) lesions developed RN. Univariate analysis revealed a significant correlation between RN and external border zone lesions, second course of SRS administered at the same site of the previous SRS, prescribed dose, and tumor volume. Multivariate analysis showed that border zone lesions, second course of SRS at the same site of the previous SRS, and tumor volume were significantly correlated with RN. CONCLUSIONS: Patients with tumors in the border zone are at high risk of RN. The potential risks of RN can be attributed hypothetically to hypoperfusion. Hence, the association between RN and border zone lesions seems reasonable.