The cross-sectional area and wrist-to-forearm ratio were associated with the pathophysiologic type of carpal tunnel syndrome, with larger nerve swellings seen in patients with axonal degeneration compared with those with demyelinating lesions. In addition to helping in the localization of the nerve lesion, sonography may indicate the type of nerve lesion.

Nitrous oxide (N 2 O) is utilized mainly for anesthetic purposes. However, these days the gas is abused in a form dubbed 'happy balloon' among the young generation for recreational purposes in nightclubs or bars. N 2 O gas interferes with cobalamin (Cbl) metabolisms, leading to axonal degeneration and a failure of my-Nitrous oxide (N 2 O) is known to induce cobalamin (vitamin B12, Cbl) deficiency, leading to myeloneuropathies. We describe two patients who present Cbl deficiency after N 2 O abuse for several months. They complained weakness of both lower limbs and gait disturbance. Their magnetic resonance imaging demonstrated high signal intensities on the dorsal columns of the spinal cord at C2-C5 on T2 weighted images, suggestive of subacute combined degeneration (SCD). Initial electrodiagnostic studies resulted in demyelinating and axonal motor dominant polyneuropathies (PNs). In these cases, Cbl deficiency due to N 2 O inhalation was suspected as the primary cause for SCD. Cbl deficiency, however, is mainly known to affect sensory nerves, and therefore difficult to account for the motor dominant PNs in our cases. Based on such fact, we suggested that N 2 O-induced motor dominant PN may occur independently from Cbl deficiency in SCD patients.

Complex regional pain syndrome (CRPS) type I in stroke patients is usually known to affect the hemiplegic upper limb. We report a case of CRPS presented in an ipsilesional arm of a 72-year-old female patient after an ischemic stroke at the left middle cerebral artery territory. Clinical signs such as painful range of motion and hyperalgesia of her left upper extremity, swollen left hand, and dystonic posture were suggestive of CRPS. A three-phase bone scintigraphy showed increased uptake in all phases in the ipsilesional arm. Diffusion tensor tractography showed significantly decreased fiber numbers of the corticospinal tract and the spinothalamic tract in both unaffected and affected hemispheres. Pain and range of motion of the left arm of the patient improved after oral steroids with a starting dose of 50 mg/day.

Carpal tunnel syndrome (CTS) is one of the most common entrapment neuropathies [1]. Selective fascicular involvement of median nerve or separate injury to the recurrent motor branch (RMB) of median nerve have been reported, but the incidence is rare with less than 1% [2]. Due to its rare incidence, physicians Carpal tunnel syndrome (CTS) being the most common entrapment neuropathy makes physicians to easily overlook CTS variants. Here we report two cases of atypical carpal tunnel syndromes which were correctly diagnosed with precise electrodiagnostic findings. One patient seemed moderate to severe degree of CTS at first, but careful electrodiagnostic analysis proved predominant involvement of fascicles of motor nerve and sensory fibers to the thumb, which are located in the radial side of the median nerve. Sonographic findings and MRI demonstrated a mass arising from the median nerve compressing the radial side of the nerve at the wrist. Another patient at a glimpse seemed as mild degree of CTS, but deliberate analysis of electrodiagnostic findings showed separate severe neuropathy of recurrent motor branch of the median nerve. Surgical findings proved these findings and the patient received appropriate surgical treatment, leading to complete resolution of symptoms. Precise analysis of electrodiagnostic findings helped physicians to correctly diagnose these atypical CTS and lead to proper management.

Study design Retrospective cross-sectional study Objectives To identify the prevalence and risk factors for low bone mass (LBM) in young adults with spinal cord injury (SCI). Setting National Rehabilitation Center in Seoul, Korea Methods This study targeted patients with SCI aged 20–49 years hospitalized from January 2010 to October 2021. Bone mineral density was assessed using dual-energy X-ray absorptiometry of the lumbar spine, femoral neck, and total hip. Results Osteopenia was diagnosed in 451 patients (58.2%), and osteoporosis was diagnosed in 156 (20.1%) of 775 patients. Among 181 patients with time from injury within 3 months, 105 (58%) and 20 (11%) were diagnosed with osteopenia and osteoporosis, respectively. Additionally, the percentage of LBM increased significantly as the time from injury increased. On multivariate analysis, the risk factors for LBM in patients with acute SCI within 12 months of onset were age (odds ratio [OR]=1.04; 95% confidence interval (CI), 1.01 to 1.07; p=0.005), female sex (OR=2.49; 95% CI, 1.34 to 4.46; p=0.002), and body mass index (OR=0.86; 95% CI, 0.81 to 0.92; p<0.001). Furthermore, alcohol or smoking history, etiology of injury, neurological level of injury, completeness of injury, and the Korean version of the spinal cord independence measure-III score were not significantly correlated with LBM. Conclusions The prevalence of osteopenia and osteoporosis is high in young adults with SCI. In addition, the diagnosis rate is high in the test performed at the initial stages after injury. Therefore, early bone health monitoring should be performed in young adults with SCI.