Background: Depression and anxiety are prevalent and can cause suffering in patients with Parkinson’s disease (PD). The Korean version of the Hospital Anxiety and Depression Scale (K-HADS) has been widely used to assess depression and anxiety symptoms in Korean patient with PD. The present study aimed to assess the reliability and validity of the K-HADS using Rasch measurement analysis.Methods: A total of 106 PD patients (54 males, 52 females) who met the diagnostic criteria of the United Kingdom Brain Bank were recruited. Unidimensionality, the Rasch model fit, response category functioning, patient-item distribution, and the separation reliability of the K-HADS depression (K-HADS-D) and anxiety (K-HADS-A) subscales were statistically evaluated.Results: The mean K-HADS-D and K-HADS-A scores were 8.08±4.69 (mean±standard deviation) and 5.44±4.18, respectively. Cronbach’s α coefficients of the K-HADS-D and K-HADS-A were 0.82 and 0.83. The Rasch analysis revealed that the K-HADS-D and K-HADS-A showed unidimensionality and no disordered functioning was observed in the 4-point polytomous scale. However, both K-HADS-D and K-HADS-A exhibited suboptimal separation reliability, while the K-HADS-A showed inadequate scale targeting with floor effect.Conclusions: The present study comprises the first validation of the K-HADS using the Rasch measurement model, suggesting that the K-HADS-D and K-HADS-A are clinimetrically acceptable and reliable scales for use in Korean patients with PD. However, the moderate person separation indices implicate the relatively low discriminatory ability of the K-HADS in our study patients.

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We developed a compact Ti:sapphire laser amplifier system in our laboratory, generating intense laser pulses with a peak power of >1 TW (terawatt), a pulse duration of 34 fs (femtosecond), a central wavelength of 800 nm, and a repetition rate of 10 Hz. The laser amplifier system consists of a mode-locked Ti:sapphire oscillator, a regenerative amplifier, and a single-side-pumped 4-pass amplifier. The chirped-pulse amplification (CPA)-based laser amplifier was found to provide an energy of 49.6 mJ after compression by gratings in air, where the pumping fluence of 1.88 J/cm2 was used. The amplified spontaneous emission (ASE) level was measured to be lower than 10−7, and ps-prepulses were in 10−4 or lower level. The developed laser amplifier system was used for the generation of intense THz (terahertz) waves by focusing the original (800 nm) and second harmonic (400 nm) laser pulses in air. The THz pulse energy was shown to be saturated in the high laser energy regime, and this phenomenon was confirmed by fully electromagnetic, relativistic, and self-consistent particle-in-cell (PIC) simulations.

We report a unique case of vertebrobasilar transient ischemic attacks manifesting as isolated, recurrent, orthostatic dizziness with posterior inferior cerebellar artery (PICA) stenosis. A 57-year-old male patient without past medical history, presented with brief orthostatic dizziness for 2 weeks. There was no associated nausea, vomiting, diplopia, or weakness. On neuro-otologic examination, the patient did not show spontaneous, positional, or gaze-evoked nystagmus. Vestibular function tests such as caloric test, head impulse test, video-oculography, and tilt table test were normal. Brain diffusion-weighted images showed multiple small high signal intensities in the bilateral cerebellar hemispheres. Brain magnetic resonance angiography revealed hypoplasia of the right vertebral artery without focal intracranial focal stenosis. Four-vessel cerebral angiogram showed severe stenosis at the right PICA artery. Our patient’s clinical scenario appears unique hemodynamic spells without symptoms or signs of posterior circulation ischemia. Physicians should also consider cerebrovascular ischemic when the patient suffers repeated orthostatic dizziness that is not explained clinically.