Assessment of Pain During Nerve Conduction Studies in Patients With Carpal Tunnel Syndrome.

Purpose: Patients with suspected carpal tunnel syndrome (CTS) often undergo nerve conduction studies (NCSs). Although patients sometimes complain of NCS-related discomfort, including severe pain, pain evaluations during such NCSs are lacking. We aimed to measure the pain experienced by patients with CTS during NCSs. Methods: This prospective study included 30 patients with CTS who underwent NCSs between April 2018 and March 2019. Pain because of electrical stimulation during NCSs was evaluated using a visual analog scale, and we statistically analyzed pain-related factors such as age, sex, complications, severity grading scale, the intensity of maximum stimulation, and examination time. Results: The mean visual analog scale score for NCSs was 5.2, and the visual analog scale score increased as the intensity of maximum stimulation and examination time increased. Conclusions: We measured the pain because of electrical stimulation experienced by patients with CTS during NCSs. Our findings indicate that medical staff must be mindful of the potential pain experienced by patients during NCSs and educate patients regarding the necessity of the examination and its procedures. Type of study/level of evidence: Diagnostic Ⅳ.

Assessment of thoracic spinal cord electrophysiological activity through magnetoneurography.

OBJECTIVE: Noninvasive and detailed visualization of electrophysiological activity in the thoracic spinal cord through magnetoneurography. METHODS: In five healthy volunteers, magnetic fields around current flowing in the thoracic spinal cord after alternating unilateral and synchronized bilateral sciatic nerve stimulation were measured using a magnetoneurograph system with superconductive quantum interference device biomagnetometers. The current distribution was obtained from the magnetic data by spatial filtering and visualized by superimposing it on the X-ray image. Conduction velocity was calculated using the peak latency of the current waveforms. RESULTS: A sufficiently high magnetic signal intensity and signal-to-noise ratio were obtained in all participants after synchronized bilateral sciatic nerve stimulation. Leading and trailing components along the spinal canal and inward components flowing into the depolarization site ascended to the upper thoracic spine. Conduction velocity of the inward current in the whole thoracic spine was 42.4 m/s. CONCLUSIONS: Visualization of electrophysiological activity in the thoracic spinal cord was achieved through magnetoneurography and a new method for synchronized bilateral sciatic nerve stimulation. Magnetoneurography is expected to be a useful modality in functional assessment of thoracic myelopathy. SIGNIFICANCE: This is the first report to use magnetoneurography to noninvasively visualize electrophysiological activity in the thoracic spinal cord in detail.

Assessment of grip-motion characteristics in carpal tunnel syndrome patients using a novel finger grip dynamometer system.

BACKGROUND: Grip strength measurement is widely used in daily medical practice, and it has been reported that the grip strength decreases in patients with carpal tunnel syndrome (CTS). However, conventional grip dynamometers evaluate only the maximum power of total grip strength and cannot measure the time course of grip motion. In this report, we aimed to determine the grip characteristics of CTS patients by measuring the time course of each finger's grip motion and to analyze the relationship between finger grip strength and subjective symptoms using this new grip system. METHODS: The grip strength of each finger was measured using the new grip system that has four pressure sensors on the grip parts of each finger of the Smedley grip dynamometer. We analyzed the time course of grip motion and relationship between finger grip strength and subjective symptoms in 104 volunteer and 51 CTS hands. The Japanese Society for Surgery of the Hand version of the Carpal Tunnel Syndrome Instrument (CTSI-JSSH) and the Disability of Arm, Shoulder, and Hand questionnaire (DASH) were used as subjective evaluation scores. RESULTS: In the CTS group, the grip time with the index, middle, and ring fingers was longer, and the time at which strength was lost after reaching the maximum was earlier. Patients with severe subjective symptoms tended to not use the index and middle fingers during grip motion. CONCLUSIONS: This new system that measures each finger's grip strength at one time and record the time course of grip motion could quantify a patient's symptoms easily and objectively, which may contribute to the evaluation of hand function.

[Efficacy of halo-vest fixation in the assessment and prediction of the effectiveness of permanent fixation in a patient with basilar invagination with ambiguous vertebral instability].

Basilar invagination is a developmental anomaly of the craniovertebral junction in which the odontoid abnormally prolapses into the foramen magnum. It is also associated with Chiari malformation, syringomyelia, and hydrocephalus. Patients require surgical treatment to prevent progression of neurological symptoms, but assessment of anterior or posterior decompression can be difficult owing to bone instability and ambiguous compression of neural structures. Here, we describe a case of basilar invagination in a young adult. He presented with neurological symptoms, including syringomyelia, 3 months after a traffic trauma that might have led to instability of the bony structures. Since it was unclear whether the instability of the bony structures contributed to the clinical deterioration, the patient was first treated using halo-vest fixation. Significant improvements were observed in both neurological symptoms and magnetic resonance images. These results justified the invasive fixation and the patient was treated further with an occipito-cervical fusion ; good results were achieved in this case. Owing to the invasiveness of the procedure, occipito-cervical fixation should only be adopted following strict indication criteria. Halo-vest fixation was effective in treating the instability of the bony structures and as a trial treatment for permanent fixation.

Assessment of choline uptake for the synthesis and release of acetylcholine in brain slices by a dynamic autoradiographic technique using [11C]choline.

The uptake of choline for the synthesis and release of acetylcholine was investigated in brain slices by dynamic positron autoradiography using [11C]choline. Brain slices (330 microm) were incubated with [11C]choline in oxygenated Krebs-Ringer medium at 34 degrees C and serial two-dimensional time-resolved images of the uptake and release of radioactivity were recorded on Storage Phosphor screens. [11C]choline uptake increased with the period of incubation and was 1.9 times higher in the striatum than cerebral cortex. The uptake in the striatum was significantly diminished by hemicholinium-3 (HC-3), an inhibitor of high-affinity choline uptake. Pretreatment of brain slices with 50 mM K(+) for 20 min enhanced the uptake in striatum. The uptake of [11C]choline in brain slices was saturable using nonlabeled choline. Two uptake systems, a high-affinity and a low-affinity system, were confirmed to exist by kinetic analysis using Lineweaver-Burk plots. The 11C radioactivity that had accumulated in the striatum disappeared on treatment with veratridine, a depolarization agent, in the presence of HC-3. This pattern of disappearance was consistent with that of the appearance of unlabeled and labeled acetylcholine in the medium. These results indicate that this method is useful for obtaining information regarding the uptake of choline for the synthesis and release of acetylcholine in live brain tissues.