Genetic, electrophysiological, and pathological studies on patients with SCN9A-related pain disorders.

BACKGROUND AND AIMS: Voltage-gated sodium channel Nav1.7, encoded by the SCN9A gene, has been linked to diverse painful peripheral neuropathies, represented by the inherited erythromelalgia (EM) and paroxysmal extreme pain disorder (PEPD). The aim of this study was to determine the genetic etiology of patients experiencing neuropathic pain, and shed light on the underlying pathogenesis. METHODS: We enrolled eight patients presenting with early-onset painful peripheral neuropathies, consisting of six cases exhibiting EM/EM-like disorders and two cases clinically diagnosed with PEPD. We conducted a gene-panel sequencing targeting 18 genes associated with hereditary sensory and/or autonomic neuropathy. We introduced novel SCN9A mutation (F1624S) into a GFP-2A-Nav1.7rNS plasmid, and the constructs were then transiently transfected into HEK293 cells. We characterized both wild-type and F1624S Nav1.7 channels using an automated high-throughput patch-clamp system. RESULTS: From two patients displaying EM-like/EM phenotypes, we identified two SCN9A mutations, I136V and P1308L. Among two patients diagnosed with PEPD, we found two additional mutations in SCN9A, F1624S (novel) and A1632E. Patch-clamp analysis of Nav1.7-F1624S revealed depolarizing shifts in both steady-state fast inactivation (17.4 mV, p < .001) and slow inactivation (5.5 mV, p < .001), but no effect on channel activation was observed. INTERPRETATION: Clinical features observed in our patients broaden the phenotypic spectrum of SCN9A-related pain disorders, and the electrophysiological analysis enriches the understanding of genotype-phenotype association caused by Nav1.7 gain-of-function mutations.

Ultrasonographic data of cervical nerve roots diameter in 100 healthy adults.

Clinically significant evaluation of the diameters of nerve roots by ultrasonography requires the establishment of a normal reference range. Although there are multiple reports of nerve root diameters in normal subjects, none of them describe how to normalize and compare data derived from different facilities that may differ in their methodology, equipment, techniques, and recording sites during data acquisition. The aim of the present investigation was to establish a dataset of normal values using 100 healthy subjects, and to identify the factors that affect the normal ranges of cervical nerve root diameters with regard to age, sex, laterality, and root segments. Compared to previous reports, smaller standard deviations (0.07-0.21) were obtained, and the coefficient of variation ranged from 0.02 to 0.08, which facilitated the precise evaluation of cervical nerve roots. Age had a significant effect on the sixth cervical nerve root (C6) in male participants, and sex had a significant effect at C6 in participants in their 60s. To establish the normal values suitable for use across different facilities, acquired using different equipment, further development of various aspects, including the sophisticated recording techniques and data-sharing capabilities, is essential.

The natural history of hereditary motor and sensory neuropathy with proximal dominant involvement (HMSN-P) in 97 Japanese patients.

Hereditary motor and sensory neuropathy with proximal dominant involvement (HMSN-P) is a motor and sensory neuronopathy with autosomal dominant inheritance, adult onset, slowly progressive course, and is associated with TRK-fused gene (TFG) mutation. At advanced stages, respiratory failure and dysphagia becomes life-threatoning, and patients typically die by their 70s. Although there is currently no evidence for effective treatment, a therapy may be found by elucidation of the function of TFG. Recently its pathomechanism has been proposed to be associated with abnormalities in protein transfer from the endoplasmic reticulum. Such pathomechanisms might involve a similar process in amyotrophic lateral sclerosis; thus, its pathomechanisms and treatment strategy might make it a good model for neurodegenerative disorders. It is of great value to clarify the natural history of HMSN-P, in oder to judge the treatment effect. By evaluating 97 patients (79 out of 97 were examined and all confirmed with p.Pro 285 Leu mutation) in this study, it was confirmed that this disease follows a uniform course in the earlier stages, and there are individual differences in the onset between 20 and 30 years. Such uniformity might be due to the proposed single gene abnormality. At advanced stages, there are larger individual differences in the progression, but the reasons for these are unknown. Longer survival might be achieved with a better care for respiratory failure and dysphagia if such cares were undertaken at appropriate times.

The Sequential Ultrasonographic, Electrophysiological and MRI Findings in a Patient with the Pharyngeal-cervical-brachial Variant of Guillain-Barré Syndrome from the Acute Phase to the Chronic Phase.

Acute progressive weakness in bulbar, neck and limbs is included in several differential diagnoses, including the pharyngeal-cervical-brachial (PCB) variant of Guillain-Barré syndrome (GBS). Patients with the PCB variant of GBS are reported to have localized diagnostic cervical spinal nerve abnormalities that can be examined by nerve ultrasonography (NUS) and magnetic resonance neurography (MRN). We herein report the case of a 77-year-old man with the PCB variant of GBS. Although the nerve conduction study (NCS) findings were indirect indicators for an early diagnosis, the combination of NCS and NUS was a useful complementary measure that facilitated an early diagnosis. MRN did not show any apparent diagnostic abnormalities. After early treatment, the patient was discharged and returned home.

[Complimentary use of needle electromyography and ultrasonography of tongue is effective for early detection of abnormality in 20 patients with amyotrophic lateral sclerosis].

A group of 20 consecutive patients with amyotrophic lateral sclerosis (ALS) were evaluated using electromyography (EMG) and ultrasonography (US) of the tongue. Their records were reviewed retrospectively for the rates at which abnormalities were detected by these two modalities as well as their clinical features. Visual inspection detected abnormalities in 9 of 20 patients, EMG in 12, and US in 6. However, EMG detected active denervation earlier than did US in 7 of the 12 EMG-diagnosed patients, and US detected fasciculation earlier than did EMG in 1 of the 6 US-diagnosed patients. Thus, we cannot replace EMG completely with US. Indeed, we currently use both methods complementarily at our hospital.

[Clinical manifestations of 5 patients with idiopathic paroxysmal kinesigenic choreoathetosis].

Paroxysmal kinesigenic choreoathetosis (PKC) is a rare disorder characterized by recurrent and brief attacks of choreoathetoid and/or dystonic movements in trunk and limbs triggered by initiation of voluntary movement. Of 5 patients with idiopathic PKC in our hospital, four were men and one was with family history. Age of onset ranged from 8 to 15 years old. They were consistent with previous reports in the characteristics of involuntary movements, normal neurological findings, normal laboratory data, no abnormal findings of standard imaging studies, and good restraining effects on attacks with carbamazepine. Individual body parts where attacks often involved were different among 5 patients. Although previous reports which said the prognosis and outcome of PKC were good, neuropsychological examinations in our study revealed that 2 patients out of 5 had certain cortical dysfunction, one patient was with progressive deterioration, and the other was with underlying mild abnormalities. Detailed and serial neuropsychological examinations might be necessary for some PKC patients.

Persistent hiccups and vomiting with multiple cranial nerve palsy in a case of zoster sine herpete.

A 76-year-old man came to our hospital complaining of hiccups and vomiting lasting for five days. A neurological examination showed dysfunction of cranial nerves V, VII, VIII, IX and X on the left side. Cerebrospinal fluid polymerase chain reaction for varicella zoster virus-DNA was positive. The patient responded well to treatment with intravenous acyclovir and steroids. To the best of our knowledge, this is the first case report of zoster sine herpete presenting with persistent hiccups and vomiting. It is important to keep in mind that herpes zoster can present with symptoms that closely resemble those of intractable hiccups and nausea of neuromyelitis optica. Early detection of the virus is critical for making appropriate treatment decisions.

[Medical cooperation using IT networks--From the medical care experience of a patient with terminal amyotrophic lateral sclerosis (ALS)].

We have created an IT network with a chat feature and have provided at-home medical care to one ALS patient through hospital-home cooperation. The IT network was operated by staff involved in hospital and at-home medical care, who recorded the details of the medical care they provided in the chat server installed at the University of Fukui Hospital via cellular phones or personal computers. During the 51-day operating period of the network, information was entered 118 times; all staff could browse this information. Hospital staff supported home medical care staff by sending replies to the questions of home staff. This experience suggested that the use of the IT network could increase the level of contribution by neurology specialists in home medical care.