Case report: Unilateral transnasal endoscopic marsupialization of nasopalatine duct cyst.

Nasopalatine duct cyst (NPDC) is the most common type of non-odontogenic cysts of the jaw. It has been treated with complete surgical resection using a sublabial or palatine approach. However, complete removal of the cyst can be accompanied by postoperative complications including oronasal fistula. Recently, endoscopic marsupialization for the disease has been advocated, but there are still few reports regarding the surgery. Herein, we report a case of NPDC that was treated with unilateral transnasal endoscopic marsupialization. A 43-year-old man with no relevant previous medical history was referred to our hospital for the treatment of lesion occupying the right nasal cavity. A computerized tomography scan of the sinus revealed an egg-shaped lesion with a well-defined border centered on the lower half of the nasal cavity and hard palate. Based on the site of the lesion, it was considered to be NPDC. Transnasal endoscopic marsupialization was performed to diagnose and improve nasal obstruction. Histopathological examination revealed stratified squamous epithelium without atypia, which was consistent with NPDC. Although the patient noticed paresthesia of the right upper incisor area, symptoms improved 3 months after surgery. Written informed consent was obtained from the patient for the publication of any potentially identifiable images or data included in this article. Transnasal endoscopic marsupialization for NPDC is minimally invasive and useful; however, it is necessary to build evidence for an appropriate excision range based on the position and size of the lesion.

Anti-TIF1-γ antibody and cancer-associated myositis: A clinicohistopathologic study.

OBJECTIVE: We aimed to analyze the clinical and histopathologic features of cancer-associated myositis (CAM) in relation to anti-transcriptional intermediary factor 1 γ antibody (anti-TIF1-γ-Ab), a marker of cancer association. METHODS: We retrospectively studied 349 patients with idiopathic inflammatory myopathies (IIMs), including 284 patients with pretreatment biopsy samples available. For the classification of IIMs, the European Neuromuscular Center criteria were applied. Patients with CAM with (anti-TIF1-γ-Ab[+] CAM) and without anti-TIF1-γ-Ab (anti-TIF1-γ-Ab[-] CAM) were compared with patients with IIM without cancers within and beyond 3 years of myositis diagnosis. RESULTS: Cancer was detected in 75 patients, of whom 36 (48%) were positive for anti-TIF1-γ-Ab. In anti-TIF1-γ-Ab(+) patients with CAM, cancers were detected within 1 year of myositis diagnosis in 35 (97%) and before 1 year of myositis diagnosis in 1. All the anti-TIF1-γ-Ab(+) patients with CAM satisfied the dermatomyositis (DM) criteria, including 2 possible DM sine dermatitis cases, and were characterized histologically by the presence of perifascicular atrophy, vacuolated fibers (VFs), and dense C5b-9 deposits on capillaries (dC5b-9). In contrast, 39 anti-TIF1-γ-Ab(-) patients with CAM were classified into various subgroups, and characterized by a higher frequency of necrotizing autoimmune myopathy (NAM). Notably, all 7 patients with CAM classified into the NAM subgroup were anti-TIF1-γ-Ab(-) and exhibited no dC5b-9 or VFs. CONCLUSIONS: CAM includes clinicohistopathologically heterogeneous disease entities. Among CAM entities, anti-TIF1-γ-Ab(+) CAM has characteristically shown a close temporal association with cancer detection and the histopathologic findings of dC5b-9 and VFs, and CAM with NAM is a subset of anti-TIF1-γ-Ab(-) CAM.

Can palm stimulation differentiate diabetic polyneuropathy from carpal tunnel syndrome?

PURPOSE: Diabetic patients without symptoms of carpal tunnel syndrome (CTS) may frequently show a prolongation of their median distal latency. Previous authors have reported that diabetic polyneuropathy (DPN) and CTS were differentiated by evaluating the sensory conduction velocity (SCV) distal to the palm. This study aimed to clarify this issue. METHODS: The subjects consisted of 30 DPN patients without clinical CTS and 50 CTS patients without diabetes mellitus. An antidromic sensory conduction study stimulating the median nerve at the wrist and palm was performed. The SCV distal to the palm (SCVpf) and across the carpal tunnel (SCVwp) and the sensory nerve action potential amplitude following palmar stimulation (AMP-p) were evaluated. RESULTS: The SCVwp was significantly lower than the SCVpf in DPN patients, implying the frequent presence of subclinical lesion at the carpal tunnel. The SCVpf was similar for both groups. The AMP-p was disproportionately low in relation to SCVwp in DPN patients, as compared with CTS patients. CONCLUSIONS: The polyneuropathic feature of DPN is primarily expressed as axonal loss. The diabetic axonal loss index has been introduced, which enabled to determine the co-presence, isolated presence, or absence of DPN/CTS in the electrophysiological sense.

Stimulus duration and pain in nerve conduction studies.

INTRODUCTION: It is generally believed that a shorter stimulus duration is less painful in nerve conduction studies (NCS). We investigated whether a shorter duration stimulus is actually less painful when the same physiological effect, such as supramaximal stimulation, is achieved in motor NCS. METHODS: The tibial nerve was stimulated at the ankle in 14 control subjects and the median nerve at the wrist in 20 subjects. Two stimulations of different durations were given blindly, and each subject was asked to report which was more painful. RESULTS: A 0.2-ms-duration stimulus was significantly less painful than those with longer or shorter durations for the tibial nerve. For the median nerve, the 0.05- and 0.2-ms durations were equally less painful than a 1-ms-duration stimulus. CONCLUSIONS: As a common duration for motor NCS, 0.2 ms seems appropriate, because the tibial nerve stimulation was more painful than the median nerve stimulation.

Decremental responses to repetitive nerve stimulation (RNS) in motor neuron disease.

OBJECTIVE: To clarify the features of decremental responses following repetitive nerve stimulation in patients with motor neuron diseases (MNDs), in comparison with myasthenia gravis (MG). METHODS: The subjects consisted of 48 MND, 39 generalized MG and 19 ocular MG patients. Six muscles, both proximal and distal muscles, were tested. RESULTS: Significant decrements (>5%) in at least one muscle were observed in 83% of the MND patients, and 74% and 47% of the generalized MG and ocular MG patients, respectively. Decrements were more frequently observed in the proximal muscles both in MND and MG patients (deltoid 76% and 62%, and trapezius 71% and 51% for MND and generalized MG, respectively), suggesting lower safety factors in neuromuscular transmission in those muscles. Decrements in the nasalis were rare in MND (8%) in comparison with generalized MG (54%). CONCLUSIONS: Decremental responses were frequently observed in MND patients. There were small differences between MND and MG regarding the distribution and other features of decrements, such as the degree of the U-shape or the responses to different stimulus frequencies and to brief exercise. SIGNIFICANCE: These results imply that the underlying mechanism regulating the decrements is common to MND and MG.

[Clinical features of predominantly sensory stroke due to brainstem infarction].

We report 13 patients presenting with predominantly sensory strokes due to brainstem infarction, without any other brainstem symptoms such as hemiparesis, dysarthria or vertigo. All of them had lacunar infarctions localized at the medial lemniscus and/or spinothalamic tract, at the pontine (12 patients) or midbrain (1 patient) tegmentum. The presenting symptom was dysesthesia with a variety of distributions for all cases, and a thalamic-pain-like unpleasant dysesthesia persisted in 4 patients. The lesion on brain MRI was usually very small, and was sometimes overlooked by radiological evaluation, which led to a long delay in the correct diagnosis of a stroke in two cases. Median nerve somatosensory evoked potentials showed a depressed N20 amplitude or a loss of the P15 potential unilaterally with preserved P13/14 potential in 7 out of 10 cases examined, and was useful in localizing the lesion intracranially. During the 4-year study period, 10 patients with brainstem infarctions were admitted to our department as acute sensory stroke cases (2.1% of all acute strokes), whereas 11 patients with thalamic infarctions (2.3%) were admitted due to similar symptoms. Cases with brainstem infarctions had sensory symptoms localized below the neck more frequently (5/10) than cases with thalamic infarctions (1/11), thus would be more likely to be confused with cervical or peripheral nerve disorders. The relative frequency of brainstem infarction as compared to thalamic infarction was higher than that in previous reports, implying that some cases with brainstem infarction might have been overlooked due to difficulty in obtaining the correct diagnosis. One should always keep this syndrome in mind when assessing patients with acute-onset sensory symptoms.