Although the usefulness of awake surgery is recognized for brain tumor, there is no report on those for spinal cord tumor. The author retrospectively studied the feasibility and usefulness of awake surgery for spinal cord tumor performed at their hospital. Case 1) 65 y.o. woman with thoracic ependymoma. Cace 2) 66 y.o. woman with cauda-equina meningioma. Case 3) 33 y.o. man with cervico-thoracic subependymoma (in 2 operations). During these 4 operations, the neurological symptoms as pain, motor weakness, sensory disturbance, and decreased tolerable volume of bladder were recognized. In such cases, the surgeon paused manipulation, then tumor was totally removed in case 1 and 2, and partially removed in case 3 because of poor recovery. Adverse events were pain, and skin injuries of grade 2 and 3. As intraoperative neurophysiologic monitoring (IONM) for spinal cord tumor surgery, somatosensory evoked potentials and motor evoked potentials are commonly used. However, they have problems of time lag, or interference to surgical maneuver, which can be overcome by awake method. Actually, in our series, neurological deteriorations were detected promptly during surgical maneuver. Skin injury could be reduced with repetition. Awake surgery for spinal cord tumor was feasible and useful for intraoperative surgeon’s decision.

To investigate whether alpha-band event-related desynchronization (ERD) /event-related synchronization (ERS) is a physiological marker for attention deficit hyperactivity disorder (ADHD), alpha-band ERD/ERS during self-reflection (SR) and working memory (WM) tasks was analyzed. For the purpose of comparing the results with those in ADHD patients in future study, whether alpha-band ERD/ERS was significantly different between SR and WM tasks was examined in 12 healthy subjects in the present study. Electroencephalogram (EEGs) were recorded from 21 scalp electrodes while the subjects (12 men, mean age: 27.4±5.3 years) performed cognitive tasks. As stimulus, one of six Japanese adjectival verbs was presented in order of pseudo-random. In the WM task, subjects were instructed to a memorize warning stimulus (S1) and subsequently judge whether S1 was identical to target stimulus (S2) presented 2 s later. In the SR task, S1 and S2 stimuli were presented in the same order as in the WM task. However, subjects were instructed to judge whether S2 was matched their character, but ignore S1. A cue stimulus (S3) for motor response was presented 2 s after S2 in both the WM and SR tasks. Subjects were instructed to push a button when S2 was identical to S1 in the WM task or when S1 was matched with own character in the SR task. Event-related changes in alpha-band power were computed from the beginning to the end of each epoch that spanned—1000 to 6000 ms using a 250-ms time window—. Repeated analysis of variance was used for statistical evaluation of the data. The dependent factor was defined as ‘ERpow’, the independent factor was defined as ‘TASK’ (WM/SR task), and the repetition factor was defined as ‘PERIOD’ (−1–0 s, 0–1 s, 1–2 s, 2–3 s, 3–4 s, 4–5 s, and 5–6 s). The significance of the discrepancy in ERpow between the WM and SR conditions in each period was tested using Scheffe’s method for multiple comparisons. There was a discrepancy in alpha-band ERpow between the WM and SR conditions 1 s before S3. While ERpow in the WM condition showed ERD, ERpow in the SR condition showed ERS in occipito-parietal areas, particularly around the mid line. Significant interaction between ‘PERIOD’ and ‘TASK’ was observed, and the discrepancy in ERpow 1 s before S3 was statistically significant. The spatio temporal pattern of ERS in the SR condition suggested that this ERS is associated with activation of the default mode network (DMN) during self-reflection process. The fact that ERS was not observed at the same timing in the WM condition supports this interpretation. Although further research is needed, studying alpha-band ERD/ERS may be useful for understanding the physiological basis underlying the attention deficit in ADHD, which could be due to a disturbance in the suppression mechanism of the DMN during a cognitive task.

Forty-four healthy subjects were randomly and evenly allocated into four groups based on the allowed motor practice time: either 10, 30, 60, or 120 seconds. F-waves were recorded at rest (resting condition). Next, subjects were asked to practice pinch force generation at 50% maximum voluntary contraction (MVC), using rapid visual feedback for guidance (MP condition). The subjects were then asked to generate pinch force at 50% MVC without visual feedback (pinch task 1). The index of accuracy (absolute error at 50% MVC for pinch task 1) was recorded. Next, these subjects were asked to perform motor imagery, and F-waves were recorded (MI condition). Finally, these subjects repeated the non-guided pinch task again (pinch task 2). Increases in persistence and F-wave/M-wave amplitude ratios (F/M-amp) were calculated by subtraction of the resting values from those in the MI condition. Increases in absolute error at 50% MVC were calculated by the subtraction of values from pinch task 2 from pinch task 1. Increases in persistence, F/M-amp, and absolute error at 50% MVC were decreased in the 30 and 60 second motor practice groups when compared to the 10 and 120 second motor practice groups. In conclusion, improvements in accuracy that result from motor imagery are not due to excessively increased excitability of spinal anterior horn cells.

We investigated the usefulness of self-assessment checklist on knowledge and degree of proficiency in neurophysiological laboratory hands-on training of medical technologists. Eleven medical technologists, 2.2±1.9 (mean±SD) years of experience, who participated in the EEG hands-on training courses for three days were evaluated. In basic course 68 check items were set, and in advanced course 30 additional items (98 in total) were set. Each item was self-evaluated in three levels (A: fully skilled and able to implement/judge by oneself, B: fully learned but unconfident about implementing/judging by oneself, C: Not fully learned) before and after the hands-on training. Trainees also evaluated the satisfaction level of the training. Ratio of level A increased from 5.5±8.6% to 47.9±23.8% after the training. The degree of satisfaction of the training was 4.6±0.5 out of 5. By using checklists for neurophysiological hands-on training, trainees can confirm their knowledge and degree of mastery, and trainers can plan throughly. Training course for only three days is insufficient to be able to implement/judge the whole items by oneself.