Jin Kubo

Brainstem function in rapid eye movement sleep behavior disorder: The evaluation of brainstem function by proton MR spectroscopy (1H‐MRS)

Brainstem function was evaluated by proton magnetic resonance (MR) spectroscopy ( 1 H‐MRS) in a 69‐year‐old man with idiopathic rapid eye movement (REM) sleep behavior disorder. An analysis of spectral peak area ratios revealed an increase in the choline/creatine ratio. This change suggests that brainstem neurons have functional impairment at the cell membrane level. Further, our results suggest that 1H‐MRS may provide for non‐invasive, metabolic evaluation of brainstem neuronal function in REM sleep behavior disorder and find application in the differentiation of secondary REM sleep behavior disorders with neurodegenerative disorders from idiopathic disorders.

Amyotrophic lateral sclerosis associated with insomnia and the aggravation of sleep‐disordered breathing

A case of amyotrophic lateral sclerosis (ALS) diagnosed by sleep‐disordered breathing is described. The patient’s chief complaints were insomnia and nocturnal dyspnea after taking a hypnotic drug. On examination, he showed restrictive ventilatory impairment, alveolar hypoventilation and hypoxia. Polysomnographic examination revealed marked hypoxia during REM sleep periods, decreased duration of REM sleep periods, and increased sleep disruption. Amyotrophic lateral sclerosis was diagnosed by the neurological finding of paraspinal muscle weakness and neurogenic changes revealed by needle electromyography and muscle biopsy. The daytime and nocturnal respiratory insufficiency improved after nasal bilevel positive airway pressure therapy. Amyotrophic lateral sclerosis should be suspected as a cause of insomnia and nocturnal dyspnea.

A comparison of middle latency auditory-evoked response in obstructive sleep apnea syndrome before and after treatment.

The ascending reticular activating system seems to be affected by nocturnal hypoxia in obstructive sleep apnea syndrome (OSAS) patients so that their vigilance level is decreased. To evaluate the change in vigilance level in OSAS patients, polysomnography, the Epworth Sleepiness Scale and middle latency auditory‐evoked responses (MLR) were measured before and after treatment in seven men with OSAS (mean age 45.4 ± 12.9 years, mean body mass index 33.3 ± 7.6 kg/m2). After treatment there was significant improvement of nocturnal hypoxia in OSAS. Peak amplitude of P1 in MLR increased after treatment. There was also improvement of the electrical field distribution of MLR on the scalp. The results suggest that the decreased vigilance level in OSAS patients is reversible with treatment.

Abnormal information processing in dementia of Alzheimer type. A study using the event-related potential's field.

Abstract Electrical field changes of event-related potentials (ERPs) were investigated in 26 patients with dementia of Alzheimers type (DAT) and 12 age-matched normal subjects. The patients were assessed with the Clinical Dementia Rating and Mini-Mental State. Each patient selected had only mild to moderate mental disability. Auditory oddball stimulation was presented at 1.5 s intervals and 1000 Hz for the nontarget and 2000 Hz for the target tones, both at 85 dB. The target tones were 20% of all the tones. The reference-independent data (latency, global field power: GFP, dissimilarity index: DISS and location of centroids) were obtained and analyzed for each ERP component. The momentary electric strength or ‘hilliness’ of the ERPs landscape was indicated by GFP. The patients showed prolonged latencies and decreased P300 GFP amplitudes and of N100 GFP. These findings suggest that the abnormal electrical field of ERP may reflect abnormal information processing following the attentional process for target stimuli in DAT patients.

Parasomnia as an occasion for the diagnosis of Parkinson's disease

We report a case of Parkinson’s disease (PD) diagnosed by REM sleep behavior disorder (RBD). The patient was a 68‐year‐old man. On admission, rigidity in the left upper and lower extremities, bradykinesia, and gait disturbance were noted. In addition, polysomnography revealed REM sleep without atonia (RWA), and a diagnosis of untreated PD associated with RBD was made. Polysomnographic data showed that REM density decreased and RWA tended to increase after administration of a combination of L‐DOPA and DCI (L‐DOPA/DCI). Thus, we considered that the pathophysiological mechanism of RBD in this case was based not only on the dysfunction of the brainstem mechanism of RWA, but also on the impairment of dopaminergic neuron.

Severe aquaporin 4-IgG-positive neuromyelitis optica with disseminated herpes zoster in a pregnant woman successfully treated with intravenous immunoglobulin:

A 26-year-old, 17-week pregnant woman developed aquaporin-4-IgG-positive severe longitudinally extensive transverse myelitis during the course of disseminated herpes zoster and became quadriparetic. She was unresponsive to high-dose intravenous methylprednisolone but became able to walk without assistance after intravenous immunoglobulin. One and a half months later, left optic neuritis developed but her vision improved with intravenous immunoglobulin. The only sequela was left T5 girdle sensation, and she delivered a healthy baby. Intravenous immunoglobulin may be a rescue therapy in aquaporin-4-IgG-positive neuromyelitis optica attacks in pregnant women, especially those with severe infections.

The efficacy of fluvoxamine for poststroke depression—an evaluation using event-related potentials topography

Abstract Poststroke depression (PSD) is known as depression after a stroke, while the depression due to silent cerebral infarction (SCI) is called MRI, defined as vascular depression (VaD). On the other hand, selective serotonin re-uptake inhibitor (SSRI) may be well tolerated and effective for the treatment of PSD and VaD. However, there is no pathophysiological study of SSRI for PSD and VaD. Event-related potentials (ERPs), especially P3 (P300), is considered an electrophysiological parameter of the cognitive processes of attention, memorization and discrimination of stimuli. To pathophysiologically determine the efficacy of fluvoxamine in a PSD patient, we submitted ERPs and made evaluations. After the administration of fluvoxamine, P3 latency decreased and its amplitude increased in the oddball and continuous performance task paradigm. In addition, the amplitude of novel P3 increased in the novel paradigm. These ERP data suggest that the improvement of the depressive state by fluvoxamine administration in this patient is based on the amelioration of the cognitive function, especially with the failure of working memory due to the frontal lobe dysfunction. Our study clarified that the cognitive dysfunction, such as mental set and working memory disturbance, existed for the part in PSD patients and its dysfunction improved with the administration of fluvoxamine.