A case of X-linked Charcot-Marie-tooth disease type 1 manifesting as recurrent alternating hemiplegia with transient cerebral white matter lesions

X-linked Charcot Marie Tooth disease type 1 (CMTX1) is a clinically heterogenous X-linked hereditary neuropathy caused by mutation of the gene encoding gap junction beta 1 protein (GJB1). Typical clinical manifestations of CMTX1 are progressive weakness or sensory disturbance due to peripheral neuropathy. However, there have been some CMTX1 cases with accompanying central nervous system (CNS) manifestations. We report the case of a genetically confirmed CMTX1 patient who presented recurrent transient CNS symptoms without any symptom or sign of peripheral nervous system involvement.

Spectrum of nitrous oxide intoxication related neurological disorders in Korea: a case series and literature review

Background: Nitrous oxide (N2O) is used in surgery and dentistry for its anesthetic and analgesic effects. However, neurological and psychiatric manifestations of N2O abuse have been increasingly reported among Korean adults. The aim of this study was to demonstrate laboratory findings of N2O abuse in Korean patients.Methods: Patients diagnosed with N2O-induced neuropathy or myelopathy from August 2018 to December 2019 were enrolled. Their clinical presentations and laboratory and imaging findings were analyzed.Results: Sensory changes and limb weakness were present in nine of the enrolled patients. The laboratory findings revealed that seven patients had high homocysteine levels and five had high methylmalonic acid levels in their blood. Nerve conductions studies indicated that axonal neuropathy was present in four cases and longer F-wave and Hoffman’s-reflex latencies were present in two cases. Signal changes in cervical spine imaging occurred in five patients, while two had normal results.Conclusions: Chronic N2O abuse can cause neurological damage or psychiatric problems. Because N2O is illegal for recreational use in Korea, patients tend to hide their history of use. Even though the spinal imaging results were normal, clinicians should consider the possibility of N2O use, and further electrophysiological tests should be applied for precise evaluations.

Usefulness of infrared thermography in diagnosing and evaluating severity of carpal tunnel syndrome

Background: Pain and autonomic dysfunction are prominent symptoms in some patients with carpal tunnel syndrome (CTS). Infrared thermography (IRT) has been used to evaluate CTS by measuring the cutaneous temperature and sympathetic vasomotor function.Methods: This study enrolled the 66 hands of 33 subjects, some of which had clinical CTS and the others were healthy. The enrolled patients completed the Boston Carpal Tunnel Questionnaire (BCTQ) and Historical-Objective scale, and underwent nerve conduction studies (NCSs) and IRT. Skin temperature was measured at the fingertips and the thenar and hypothenar regions in each hand. We analyzed (1) the correlations between self-reported severity, physician-assessed severity, and test results, and (2) the sensitivity and specificity of IRT in diagnosing CTS.Results: No significant correlation was observed between the results of the BCTQ, NCS, and IRT. IRT had a low sensitivity and high specificity in diagnosing CTS.Conclusions: IRT cannot replace NCS in diagnosing CTS, nor did it provide an advantage in combination with NCS. However, lower temperatures at the median nerve in some hands with moderate-to-severe CTS suggested the involvement of sympathetic nerve fiber function. Follow-up studies with a larger-scale and complementary design are required to elucidate the relationships.

Autonomic dysfunction in postoperative primitive neuroectodermal tumor of heart

We present a patient with a primitive neuroectodermal tumor arising from the right atrium who experienced multiple syncope episodes daily, which had first appeared 1 month after surgery. The symptoms continued to worsen over the course of chemotherapy, and the autonomic function test (AFT) was performed after the 14th chemotherapy cycle. The AFT revealed orthostatic hypotension and reduced baroreflex-dependent sympathetic reactivity. Physical counterpressure techniques were applied with a visual biofeedback intervention, and were found to be effective in reducing the syncope episodes.

Autonomic instability in severe tetanus: a case report

Tetanus is an infectious disease of the nervous system caused by Clostridium tetani, and is characterized by tonic muscle contractions, painful spasms, and autonomic dysfunction. Severe autonomic dysfunction associated with tetanus can be life-threatening. We present a 62-year-old female who experienced lockjaw after an ankle fracture. The patient was diagnosed with tetanus and received tetanus immunoglobulin and a vaccination. The patient subsequently experienced labile hypertension. This case highlights the challenge and importance of managing cardiovascular instability.

New approach of using cortico-cortical evoked potential for functional brain evaluation

Cortico-cortical evoked potential (CCEP) mapping is a rapidly developing method for visualizing the brain network and estimating cortical excitability. The CCEP comprises the early N1 component the occurs at 10-30 ms poststimulation, indicating anatomic connectivity, and the late N2 component that appears at < 200 ms poststimulation, suggesting long-lasting effective connectivity. A later component at 200-1,000 ms poststimulation can also appear as a delayed response in some studied areas. Such delayed responses occur in areas with changed excitability, such as an epileptogenic zone. CCEP mapping has been used to examine the brain connections causally in functional systems such as the language, auditory, and visual systems as well as in anatomic regions including the frontoparietal neocortices and hippocampal limbic areas. Task-based CCEPs can be used to measure behavior. In addition to evaluations of the brain connectome, single-pulse electrical stimulation (SPES) can reflect cortical excitability, and so it could be used to predict a seizure onset zone. CCEP brain mapping and SPES investigations could be applied both extraoperatively and intraoperatively. These underused electrophysiologic tools in basic and clinical neuroscience might be powerful methods for providing insight into measures of brain connectivity and dynamics. Analyses of CCEPs might enable us to identify causal relationships between brain areas during cortical processing, and to develop a new paradigm of effective therapeutic neuromodulation in the future.

Refractory Bell’s palsy responding to late treatment with high-dose intravenous steroids

Bell’s palsy is an acute peripheral facial paralysis with no detectable cause. Although the prognosis of Bell’s palsy is generally good, some patients experience poor recoveries and there is no established treatment for those that do not recover even after receiving the conventional treatment. Here we present two cases of refractory Bell’s palsy with facial nerve enhancement in magnetic resonance imaging who showed symptomatic improvement after the late administration of high-dose intravenous methylprednisolone.

A case of motor and sensory polyneuropathy induced by primary hyperparathyroidism

Primary hyperparathyroidism (PHP) is a disease in which excessive amounts of parathyroid hormone (PTH) are secreted and calcium levels in the blood increase. Hypercalcemia caused by PHP has a major influence on the peripheral nervous system and produces symptoms such as muscle cramps, paresthesia, and proximal muscle weakness. Here we report a rare case of sensory-dominant polyneuropathy caused by PHP, which improved after surgery.

Carotid duplex ultrasound: interpretations and clinical applications

Carotid duplex ultrasound is commonly used to diagnose various carotid artery diseases due to it being noninvasive and easy to perform. Carotid atherosclerosis is a major indicator for the need to perform carotid duplex ultrasound, which can determine the degree of stenosis, plaque characteristics, and intima-media thickness. It can also be used to screen and follow-up after carotid revascularization. Here we discuss the standard techniques, interpretations, and clinical indicators for carotid duplex ultrasounds.

Introduction of brain computer interface to neurologists

A brain-computer interface (BCI) is a technology that acquires and analyzes electrical signals from the brain to control external devices. BCI technologies can generally be used to control a computer cursor, limb orthosis, or word processing. This technology can also be used as a neurological rehabilitation tool for people with poor motor control. We reviewed historical attempts and methods toward predicting arm movements using brain waves. In addition, representative studies of minimally invasive and noninvasive BCI were summarized.