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Type 2 diabetes mellitus patients are immunocompromised, particularly under poorly controlled conditions, and thereby they could develop rare inflammatory diseases, such as spontaneous discitis, pyogenic psoas abscess, spinal epidural abscess and bacterial meningitis. Herein we report a pyogenic psoas abscess on the dorsal side, and bacterial meningitis and spinal epidural abscess on the ventral side, both of which were induced by spontaneous discitis in a patient with poorly controlled type 2 diabetes mellitus. This case was very rare and interesting, because we successfully treated various infections with antibiotics over a long period of time, complicated by hyperglycemic crises, although the patient suffered severe bone destruction and required rehabilitation for a long time.

Posterior antebrachial cutaneous (PABC) nerve conduction studies could be useful for distinguishing PABC neuropathy from C7 radiculopathy. In the conventional method using an antidromic method, the sensory nerve action potential (SNAP) is sometimes followed by a large volume-conducted motor potential. In this report we describe a reliable nerve conduction study using an orthodromic method for recording SNAPs of the PABC nerve.Thirty-six healthy volunteers participated in this study. PABC SNAPs were recorded by placing a surface-active electrode 2 cm anterior to the lateral epicondyle. The PABC nerve was stimulated 10 cm distal to the active recording electrode along a line from the recording point to the mid-dorsum of the wrist, midway between the radial and ulnar styloid processes. We also performed PABC nerve conduction studies using an antidromic method and compared the findings.PABC SNAPs were recorded bilaterally from all subjects. The mean peak-to-peak amplitude for SNAPs was 13.4 ± 4.8 μV. Mean maximum conduction velocity was 62.7 ± 3.9 m/s and mean negative peak conduction velocity was 51.2 ± 2.6 m/s. The mean side-to-side difference in amplitude was 22.1 ± 16.0%. The mean amplitude of SNAPs obtained by our method was 48.9% higher than that of SNAPs obtained by the conventional method (13.4 vs 9.0 μV; P .001). In contrast to the conventional method, our method enabled SNAPs to be recorded without a volume-conducted motor potential.The higher mean amplitude of SNAPs with our method enables them to be obtained easily.

An 87-year-old woman was admitted to our hospital because of speech disturbance and right facio-pharyngo-glosso-masticatory diplegia. She had bronchial asthma, was previously diagnosed with cerebral infarction, had experienced two events of convulsive status epilepticus, and was undergoing treatment with theophylline, levetiracetam, and clopidogrel. Head diffusion-weighted magnetic resonance imaging revealed a high-signal area in the left crus posterior capsula interna. For this, we administered cilostazol along with her regular medicines. On day 14, she had tonic-clonic convulsions, extending from the right upper and lower limbs to the whole body. Subsequently, cilostazol was discontinued, and the dose of levetiracetam was increased. However, she developed severe tonic-clonic seizures with right sensory aphasia and right hemiplegia, for which an increased dose of lacosamide was added. When theophylline was discontinued 5 days after the onset of convulsions, the blood concentration of theophylline was 9.7μg/mL. After theophylline was discontinued, tonic-clonic convulsions improved. The disturbance of consciousness and right hemiparesis were improved after one week, while the disturbance of sensory aphasia was improved after one month. We suspect that cerebral infarction may have aggravated the central nervous system damage caused by theophylline, thereby resulting in aminophylline-related non-convulsive status epilepticus. (Received 20 July 2020; Accepted 27 October 2020; Published 1 March 2021).

Introduction In this study we evaluated anatomic variations of the superficial branch of the radial nerve (SBRN) and the dorsal branch of the ulnar nerve (DBUN) electrophysiologically. Methods Antidromic nerve conduction studies (NCS) of the SBRN and DBUN were performed on healthy individuals. To identify individual responses from the distal branches of the SBRN and DBUN, sensory nerve action potentials of each finger (lateral side/medial side) were recorded. Results NCS were performed in 50 hands of 27 healthy control subjects. The thumb and the index finger were supplied by the SBRN in all cases. The lateral and medial sides of the third finger were supplied by the SBRN in 94.0% and 74.0% of the cases, but the lateral and medial sides of the fourth finger were supplied by the SBRN in only 10.0% and 2.0% of cases. The fifth finger and the medial side of the fourth finger were always supplied by the DBUN. The lateral side of the fourth finger was supplied by the DBUN in 98.0% of cases, but the lateral and medial sides of the third finger were supplied by the DBUN in 40.0% and 70.0% of cases. Dual innervation by the SBRN and DBUN was found in 34.0% and 46.0% of the lateral and medial sides of the third finger, but in only 8.0% and 2.0% of the lateral and medial sides of the fourth finger. Discussion There are considerable anatomic variations of the SBRN and DBUN in healthy individuals.

Objective To achieve an accurate quantification in diabetic polyneuropathy (DPN), we developed a new electrophysiological index that we called the DPN index. The relationship between the DPN index and the neurological findings in diabetic patients was assessed. Methods The DPN index was calculated by the mean value of percentages of four parameters (tibial compound muscle action potential amplitude / F wave minimum latency, sural sensory nerve action potential amplitude / sensory nerve conduction velocity) against the mean normal values. Twenty healthy subjects were recruited as a control group. Patients A total of 348 diabetic patients who were hospitalized in our hospital during the period from December 2016 to August 2019 were retrospectively studied. The correlations between the DPN index and five neurological findings (subjective sensory symptoms, diminished or absent Achilles tendon reflex, impaired tactile and vibration sense, low coefficient of variation of R-R interval) were evaluated. Results The DPN index in healthy subjects was 129.3±32.7%. The DPN index in diabetic patients with one or more neurological findings was significantly lower than that in diabetic patients without any neurological findings (p

Highlights • The active recording electrode site influences the CMAP waveform of the trapezius muscle (TM). • CMAP becomes high by placement of the active recording electrode 2 cm behind the belly of the TM. • Volume conduction from the supraspinatus muscle affects the CMAP waveform of the TM., Objective We investigated how the active electrode placement site influences compound muscle action potential (CMAP) configuration of the upper trapezius muscle (TM). Methods A nerve conduction study of the accessory nerve was performed, and the CMAPs obtained with two different placement sites, i.e., placement of the active recording electrode on the belly of the upper TM (CMAP-A) and placement of the electrode 2 cm behind the belly (CMAP-B), were compared. CMAPs were also obtained with the active recording electrode placed in the supraspinous fossa (CMAP-C). Results All CMAPs were recorded from 21 healthy volunteers. The mean peak-to-peak amplitude of CMAP-B was 3.4 mV higher than that of CMAP-A (11.0 ± 4.0 mV vs. 14.4 ± 4.9 mV; P

Objective To obtain higher amplitude of dorsal sural sensory nerve action potentials (SNAPs), we used a new method for dorsal sural nerve conduction study with surface strip electrodes (SSEs). Methods Dorsal sural SNAPs were recorded orthodromically. The recording electrodes were placed behind the lateral malleolus. SSEs were attached to the laterodorsal aspect of the foot for stimulation of the dorsal sural nerve (DSN). We also used a conventional method with a standard bipolar stimulator and compared the findings. Results Dorsal sural SNAPs were recordable bilaterally from 49 healthy volunteers. Mean peak-to-peak amplitude for SNAPs was 12.9 ± 6.3 μV, and mean nerve conduction velocity was 44.8 ± 5.5 m/s. The mean amplitude of SNAPs obtained by our method was 118.6% higher than that of SNAPs obtained by the conventional method (12.9 μV vs. 5.9 μV; P Conclusions The highest amplitude of dorsal sural SNAPs was constantly obtained by SSEs since SNAPs arising from whole digital branches of the DSN could be elicited by placement of SSEs. Significance When the DSN supplies more cutaneous branches to the lateral half of the foot, SSEs gives higher amplitude of dorsal sural SNAPs than that of the standard innervation type.

Background There are few reports of anti-myelin oligodendrocyte glycoprotein (MOG) antibody-positive, unilaterally dominant cerebral cortical encephalitis onset with epilepsy. We present such a case in a young female patient with myelitis. Case presentation A 19-year-old female developed generalized tonic seizures lasting several minutes. She had a low-grade fever and headache without other clinical neurological abnormalities while at our hospital. Cerebrospinal fluid (CSF) showed mononuclear pleocytosis. Other laboratory tests indicated no apparent abnormalities. Unilateral meningeal hyperintensity was seen on T2 fluid-attenuated inversion recovery MRI with associated cortical swelling and gadolinium enhancement of the cortical layer. One thousand mg/day of levetiracetam and a 3-day course of intravenous methylprednisolone at 1000 mg/day were administered. Dysuria appeared on the twentieth day of illness, and spinal MRI revealed a longitudinally extensive cord lesion from C5 to L1 consistent with myelitis. Two cycles of a 3-day course of intravenous methylprednisolone at 1000 mg/day were administered, and all symptoms disappeared. We found the patient to be anti-MOG antibody-positive using serum and CSF (titer: serum 1:256; CSF 1:128). Conclusion Our report illustrates a unique case of anti-MOG presenting as new onset epilepsy secondary to unilaterally dominant meningoencephalitis preceding the onset of longitudinally extensive transverse myelitis.

Introduction We evaluated anatomic variations of distal branches of the superficial fibular sensory nerve electrophysiologically. Methods Orthodromic nerve conduction studies (NCS) of the first and third branches (M-I, M-III) of the medial dorsal cutaneous nerve and the fourth and fifth branches (I-IV, I-V) of the intermediate dorsal cutaneous nerve (IDCN) were performed. To find anomalous innervations from the dorsal sural nerve (DSN) in the IDCN territory, NCS of the fourth and fifth branches (S-IV, S-V) of the DSN were also performed. Results All sensory nerve action potentials (SNAPs) of M-I and M-III could be obtained bilaterally from 31 healthy Japanese volunteers. SNAPs of I-IV and I-V were recordable in 85.5% and 43.5% of feet, respectively. Anomalous innervations from the DSN were confirmed in 71.0% of S-IV and 93.5% of S-V. Conclusion These results suggest that anatomical variations in the IDCN territory are very frequent in Japanese subjects. Muscle Nerve 55: 74-76, 2017.

Aim The underlying etiology of dropped head syndrome (DHS) in Parkinson's disease (PD) patients seems to be heterogeneous, that is neck dystonia, a drug-induced etiology or focal myopathy of the neck extensor muscles. Focal myopathy might be primary myositis or a stretched muscle injury. In Japan, several reports have argued that neck dystonia is the cause of DHS. There have been no reports to date that documented a focal myopathy of the neck extensor muscles. The aim of the present study was to investigate myopathic changes in the neck extensor muscles of PD patients with DHS by needle electromyography (EMG), and to evaluate the effect of steroid therapy. Methods We carried out needle EMG on 15 consecutive PD patients with DHS who visited our hospital between July 2009 and November 2011. The effects of prednisolone for the treatment of DHS were evaluated clinically and electrophysiologically. Results Needle EMG of the neck extensor muscles in 15 PD patients with DHS revealed fibrillation potentials, positive sharp waves and small amplitude, short duration motor unit potentials in 14 patients. EMG findings were indicative of focal myopathy in five patients, and were compatible with focal myopathy in nine patients. DHS improved in eight out of 11 patients given prednisolone 20 mg/day. Follow-up needle EMG after steroid therapy in four patients showed improvements in the myopathic changes. Conclusion We report that focal myopathy of the neck extensor muscles is common in Japanese PD patients with DHS. Our findings suggest that steroid therapy might improve DHS in some PD patients.

Introduction: The compound muscle action potential (CMAP) following ulnar nerve stimulation receives a considerable contribution from far-field potentials (FFPs), although their origin is not entirely clear. We investigated this issue using voluntary contractions. Methods: In 7 control subjects, we placed multiple recording electrodes over the motor points of ulnar-innervated muscles. We asked the subjects to perform a weak movement corresponding to the action of each muscle, and identified the single motor unit potentials (MUPs) from that muscle. We summed the MUPs from each individual muscle and reconstructed the CMAPs. Results: The reconstructed CMAPs coincided well with the actual ones. The N1, P1, and early N2 components of the FFPs were generated primarily by palmar, but also by dorsal, interosseous muscles. The abductor digiti minimi muscle usually generated positive–negative biphasic FFPs, and the negative FFP generated the late N2 component. Conclusions: These results should prompt a revision of the theory of FFP generation. Muscle Nerve, 2011

Neck dystonia is the most common cause of dropped head sign in parkinsonism. Isolated neck extensor myopathy, which is a rare condition, can also cause dropped head sign in parkinsonism, but no improvement has been achieved with immunosuppressive therapy. We report three cases of treatable neck extensor myopathy causing dropped head sign in patients with Parkinson's disease. Needle electromyography and magnetic resonance imaging suggested a restrictive active myopathy affecting neck extensor muscles. All cases responded dramatically to steroid therapy. Routine needle electromyography should be performed to explore treatable myopathy in Parkinson's disease.

Introduction: In this report we describe a reliable method for recording sensory nerve action potentials (SNAPs) of the supraclavicular nerve. Methods: Supraclavicular SNAPs were recorded by placing a surface active electrode at the pos- terior border of the sternocleidomastoid muscle at a distance of 6 cm from the sternoclavicular joint. The nerve was stimulated at the lower border of the clavicle 4.5 cm lateral to the sterno- clavicular joint. Results: Supraclavicular SNAPs were recorded bilaterally from 20 healthy volunteers. Mean onset latency was 1.0 60.2 ms, and mean peak latency was 1.4 60.3 ms. Mean baseline-to-peak amplitude for the SNAPs was 6.1 62.2 mV, and mean maximum conduction velocity was 59.8 66.2 m/s. The mean percentage of side-to-side difference in amplitude was 12.9 611.0%. Conclusion: Supraclavicular SNAPs could be obtained in all normal subjects. Assessment of supraclavic- ular nerve conduction is very useful in the diagnosis of supra- clavicular neuropathy Muscle Nerve 000:000-000, 2014

大阪層群最下部層の朝代テフラ層は，淡路島や古琵琶湖層群，氷見層群，飯能礫層などに挟在するテフラ層と広く対比されている．一方，新潟地域中央油帯の西山層のTzwテフラ層は，西山油帯，佐渡島，それに北蒲原地域からも見出されている．今回，この両テフラ層の対比を検討した．両テフラ層は広域テフラ層である土生滝I—MT2—Arg-2テフラ層よりも上位にあり，古地磁気層序におけるガウス・マツヤマ境界よりも下位にある．また，記載岩石学的特徴も類似する．火山ガラスの化学組成は，中央日本に分布するテフラとしてはともにTiO2やMgOがやや高い値を示し，ほかの酸化物含有量についても酷似する．以上のことから，両テフラ層は対比される．その年代については，北蒲原地域の古地磁気層序や微化石年代層序との関係などから，2.6 Maないしそれよりやや古い年代が想定される．今後，この朝代-Tzwテフラ層はガウスクロノゾーン最上部を示す広域テフラ層として，その活用が期待される．

Nerve conduction studies (NCSs) are essential to the work up of peripheral neuropathy. NCSs are useful in vasculitic neuropathy because they can serve as a guide in the nerve biopsy, as well as detect asymptomatic vasculitic neuropathy. NCSs characteristically show axonal loss of motor and sensory fibers with asymmetric or non-length-dependent patterns. Occasionally, conduction block (CB) or pseudo CB are observed. Pseudo CB is appears in the acute phase before Wallerian degeneration has developed distal to the infarcted nerve, and then disappears within two weeks.

We evaluated two patients who were considered as having complicated form of familial spastic paraplegia (FSP). Patient 1 was a 37-year-old male, having slowly progressive walking difficulty. Examination revealed dementia, nystagmus, slurred speech, spastic paraparesis and increased reflexes. His sensation was normal. Patient 2 was a 35-year-old male. Examination revealed dementia, dysarthria, spastic paraparesis, increased reflexes and slightly decreased vibration sense in the ankle. We examined the median and tibial short-latency somatosensory-evoked potentials (SEPs). In patient 1, N9o-P13/14o and P13/14o-N20o intervals were prolonged in the median SEPs. ‘N9o’ means N9 onset. N21–N30 and N30–P38 intervals were prolonged in tibial SEPs. In patient 2, P13/14o latency was normal, but N20 was lost in the median SEPs. N30 latency was normal, but P38 was lost in the tibial SEPs. The present results indicate defective transmission in the somatosensory pathway, especially in its intracranial portion, in patients with complicated form of FSP. This contrasts with findings in patients with pure form of FSP, who usually show defective transmission only in the thoracic spinal portion. SEPs showed abnormal findings, even in a patient without sensory disturbances. SEPs are useful for localizing the lesion sites and for differential diagnosis between the pure and complicated forms of FSP.

Objective In rats the available techniques for evaluation of sensory nerve conduction are limited. We report a new method of sensory nerve conduction of the plantar nerve using needle electrodes as the recording electrodes behind the medial malleolus and ring electrodes as the stimulating electrodes around the three middle toes. Methods We performed this sensory nerve conduction test in 25 rats during their growth over a 6 weeks' period and compared this method with the motor nerve conduction and H-reflex sensory nerve conduction of the tibial nerve in 10 rats, and with the motor and mixed nerve conductions of the tail nerve in 15 rats. Results There was a highly or moderately significant correlation between the body weight and sensory nerve conduction velocity (NCV) of the plantar nerve, mixed NCV and motor NCV of the tail nerve, indicating a growth-related increase in the NCV. The growth-related increase in the NCV was not observed in the motor and H-reflex sensory nerve conductions of the tibial nerves. Conclusions This test is simple and reliable and can be used for the sensory nerve conduction test in rats.

A new method to evaluate whole plantar nerve conduction with disposable strip electrodes (DSEs) is described.Whole plantar compound nerve action potentials (CNAPs) were recorded at the ankle. DSEs were attached to the sole for simultaneous stimulation of medial and lateral plantar nerves. We also conducted medial plantar nerve conduction studies using an established method and compared the findings.Whole plantar CNAPs were recorded bilaterally from 32 healthy volunteers. Mean baseline to peak amplitude for CNAPs was 26.9 ± 11.8 μV, and mean maximum conduction velocity was 65.8 ± 8.3 m/s. The mean amplitude of CNAPs obtained by our method was 58.2% higher than that of CNAPs obtained by the Saeed method (26.9 μV vs. 17.0 μV; P 0.0001).The higher mean amplitude of whole plantar CNAPs obtained by our method suggests that it enables CNAPs to be obtained easily, even in elderly people.

In this report we describe a reliable method for recording sensory nerve action potentials (SNAPs) of the supraclavicular nerve.Supraclavicular SNAPs were recorded by placing a surface active electrode at the posterior border of the sternocleidomastoid muscle at a distance of 6 cm from the sternoclavicular joint. The nerve was stimulated at the lower border of the clavicle 4.5 cm lateral to the sternoclavicular joint.Supraclavicular SNAPs were recorded bilaterally from 20 healthy volunteers. Mean onset latency was 1.0 ± 0.2 ms, and mean peak latency was 1.4 ± 0.3 ms. Mean baseline-to-peak amplitude for the SNAPs was 6.1 ± 2.2 µV, and mean maximum conduction velocity was 59.8 ± 6.2 m/s. The mean percentage of side-to-side difference in amplitude was 12.9 ± 11.0%.Supraclavicular SNAPs could be obtained in all normal subjects. Assessment of supraclavicular nerve conduction is very useful in the diagnosis of supraclavicular neuropathy.

A 77-year-old man was admitted because of muscle weakness in both upper and lower extremities. Diabetes mellitus was diagnosed in 1988 and he had been treated by oral hypoglycemic agents. He had a common cold at the end of January, 1997. Muscle weakness appeared in the upper extremities, followed by the lower extremities at the end of February. No sensory disturbance or dysuria was recognized. Nerve conduction study revealed distally dominant demyelinating polyneuropathy. Guillain-Barré's syndrome was diagnosed and he recovered completely following immunological absorption therapy (IAT). However, he had quadriplegia again at the end of April. He was treated by IAT combined with corticosteroid and has shown no relapse. In June, 1997, gastric cancer was detected by upper gastrointestinal fiberscopy and subtotal gastrectomy was performed. Judging from this clinical course, this case seems to be chronic inflammatory demyelinating polyneuropathy (CIDP) with acute onset. Many kinds of causes often contribute to the pathogenesis of neuropathy in the elderly. So in cases of progression or worsening, we should consider such possibilities and it is necessary not to exclude treatable causes of neuropathy.

The purpose of this study was to assess the relationship between mental fatigue and event-related potentials (ERPs). Six healthy men (mean age: 22 years old) performed a simple calculation for 6 h. Auditory ERPs were recorded before and after the calculating task. The scores of subjective fatigue symptoms were significantly increased, and P300 latency of auditory ERPs was significantly prolonged by the calculating task (P

A 54-year-old man presented with tremor and unusual behavior. He was admitted two months later because of dementia and myoclonus. Periodic synchronous discharges were observed on the electroencephalogram. Based on these findings, we diagnosed the case as Creutzfeldt-Jakob disease. About two weeks after admission, decubitus, bowel dysfunction and hypohidrosis occurred. We observed various autonomic nervous system dysfunctions such as abnormal pupillary response to autonomic drugs, reduced coefficient of variation of R-R interval, and abnormal diurnal blood pressure variation.

We report a case of fulminant brachial plexopathy with radicular involvement. A 25-year-old man developed acute total monoplegia in the left upper limb. Needle electromyography showed extensive acute denervation in the C5-T1 spinal segments, and peripheral sensory nerve conduction was normal, mimicking a pre-ganglionic lesion. However, left median somatosensory evoked potentials revealed abnormal Erb's point potential, suggesting a brachial plexus lesion. Corticosteroid treatment resulted in good recovery. These findings suggest that the primary pathophysiology was conduction block and this can explain the good clinical recovery in this patient.

To determine the conversion factor (CF) of the sural nerve the correlation between the maximum nerve conduction velocity (NCV) and the diameter of the largest fibers was studied in 30 patients suspected of having neuropathy. Sensory nerve action potentials were obtained by on-nerve needle nerve conduction study using needle electrodes placed on the exposed sural nerve during biopsy. The CF was 4.3 (n = 2) in normal sural nerves and close to the normal value (3.85, n = 4) in axonal neuropathy. The CF in demyelinating neuropathy was smaller than the normal value (2.77, n = 24), indicating disproportionately slower conduction than expected from the diameter of nerve fibers. The CF was helpful in differentiating between demyelinating and axonal neuropathies. We propose that a 36% decrease from the mean value of NCV is a reasonable criterion for demyelination of the nerve.

We describe a 52-year-old man with a history of increasing fatigability and gait disturbances that were first attributed to hypothyroidism. On examination, he had bilateral pseudo-internuclear ophthalmoplegia with weakness of adduction and abducting nystagmus. Convergence was also impaired and he showed proximal weakness of the limb. Intravenous edrophonium almost completely abolished the nystagmus and adducting muscle weakness, and improved the strength of proximal muscles groups. The clinical response to the administration of edrophonium, the presence of AChR binding antibodes and the repetitive nerve stimulation test findings indicated that the patient had pseudo-internuclear ophthalmoplegia as a manifestation of generalized myasthenia gravis. Whereas hypothyroidism was effectively controlled with levothyroxine, his subsequent response to thymectomy, prednisolone and cholinesterase inhibitors confirmed the diagnosis of generalized myasthenia gravis.

Undifferentiated carcinomas of the colon are rare, especially macroscopic expansive polypoid type. Only few cases have been reported so far. Recently, we experienced such a rare case. A 71-year-old male patient came in the hospital because of some symptoms suggestive of intestinal obstruction. General diagnostic work-up, including colon biopsy, revealed a primary undifferentiated carcinoma of the sigmoid colon and radical operation was performed. Undifferentiated carcinomas of the colon and rectum would demand general diagnostic work-up in the differentiation from others such as carcinoid, malignant lymphoma, malignant melanoma, and metastasis of pulmonary carcinoma. In addition appropriate selection of antitumor drugs in terms of histological findings would be important in the adjuvant chemotherapy.

Background and Purpose: We report decremental responses to repetitive nerve stimulation (RNS) in 11 patients diagnosed with X-linked spinobulbar muscular atrophy (X-SBMA). Methods: The compound muscle action potential (CMAP) of the right abductor digiti minimi (ADM) and trapezius (TZ) in response to a 3-Hz stimulation of the ulnar nerve at the wrist and accessory nerve at the neck were recorded by surface electrodes. Results: A decremental response to RNS was observed in 90.9% of the TZ muscle and 27.2% in the ADM muscle of patients with X-SBMA. Conclusion: These electrophysiological features of X-SBMA are considered to be useful for diagnosis of X-SBMA. Furthermore, the waning phenomena that mostly appeared in the TZ muscle and increment of CMAP in RNS after the exercise also suggest a unique manifestation in X-SBMA.

A 27-year-old woman presented with acute paresis after taking an oral polio vaccine (OPV). Deep tendon reflexes were preserved, needle electromyography showed no neurogenic changes, and there were no lesions on spine magnetic resonance imaging (MRI), suggesting that motor neurons of the spinal cord were not affected. Brain MRI showed abnormal lesions in the tegmentum of the upper pons, left cerebral peduncles, truncus of the corpus callosum, and right parietal lobe. Cerebrospinal fluid revealed mild pleocytosis. The most probable diagnosis was acute disseminated encephalomyelitis associated with OPV.

OBJECTIVE: The nerve conduction findings in interdigital neuropathy of the foot (IDN; Morton's neuroma) have rarely been reported. We analyzed the nerve conduction data in 23 patients with suspected IDN studied between 1982 and 2002. METHOD: Diagnosis of IDN was made on the basis of clinical features. All patients underwent routine nerve conduction studies and a near-nerve needle sensory nerve conduction study of the interdigital nerves by Oh's method in the symptomatic foot. RESULTS:Of the 23 patients, the diagnosis of definite IDN was made in 13 cases and of possible NDN in the others cases. Nineteen were females. Twenty two patients had only one nerve affected. One patient had two nerves affected. The III-IV interdigital nerve was affected in 17 cases and the II-III interdigital nerve in 7 cases. The near-nerve needle nerve conduction showed abnormality in the affected interdigital nerves in all definite IDN cases and confirmed the diagnosis of IDN in 10 cases by the abnormal dip phenomenon (a selective decrease of 50% or more in the sensory CNAP amplitude of the affected nerve compared with that of the preceding interdigital nerve). In 11 possible IDN cases, IDN was identified by the abnormal dip phenomenon. CONCLUSION: The near-nerve needle sensory nerve conduction of the interdigital nerves is a highly sensitive diagnostic test, and abnormal dip phenomenon is the most characteristic electrophysiological marker for the diagnosis of IDN.

A 61-year-old female, having intractable hiccups, nausea, and syncope. Her systolic blood presure decreased by 30 mmHg on sitting position from supine position. Sinus arrest lasting more than three seconds were detected 52 times per day by 24 hour Holter electrocardiography. Brain MRI disclosed a small hyperintense lesion in the medullary tegmentum on T2-weighted images. She was diagnosed as having a relapse of multiple screlosis and her symptoms were improved by administration of high dose methylprednisolone (1,000 mg per day x 3 days) intravenously. In a patients, a stimulative lesion in the medullary tegmentum was suspected where the reflex centers of hiccups, nausea and blood pressure to exist. We are able to confirm a small hyperintense lesion in such a particular region by brain MRI. In case of syncope accompanied with intractable hiccups and nausea, we should consider a stimulative lesion in the medullary tegmentum. Moreover, sinus arrest other than orthostatic hypotension may be involved in the pathophysiology of syncope in correlation with the medullary tegmentum lesion.

The authors performed nerve conduction studies in nine PARK2 and eight idiopathic Parkinson disease patients and found a significant reduction of sural sensory nerve action potential (SNAP) amplitude in eight PARK2 patients who mostly remained asymptomatic. These data suggest that sensory axonal neuropathy may be a common clinical feature of PARK2 and a reduced amplitude of sural SNAP could be a diagnostic indicator of PARK2.

Various parameters of the repetitive nerve stimulation (RNS) test of the abductor digiti quinti muscle were analyzed statistically in 34 patients with Lambert-Eaton myasthenic syndrome (LEMS). The sensitivity and specificity of the increments after exercise and after 50-HZ stimulation for the diagnosis of LEMS were compared with reference values in 40 normal subjects and data from 538 tests in patients with myasthenia gravis (MG). When we used a 100% increment (the "gold standard") as the normal limit for the postexercise facilitation (PEF) or the high-rate stimulation (HRS) test, the diagnosis of LEMS was confirmed in 29 (85%) cases. When a 60% increment was used as the normal limit, the diagnosis of LEMS was made in 97% of cases. In MG, a 60% increment was observed in only 4 of 538 cases by HRS and in none by the exercise test. Thus, the use of a 60% increment showed a sensitivity of 97% for the diagnosis of LEMS and a specificity of 99% in excluding MG. A 60% increment in either the PEF or HRS test for the diagnosis of LEMS is a desirable alternative to the 100% increment previously considered to be the gold standard for this diagnosis.

Objective: To report the clinical, electrophysiologic, and histologic characteristics of subacute inflammatory demyelinating polyneuropathy (SIDP) and to present the diagnostic criteria of this disease. Methods: For a diagnosis of “definite SIDP,” there were four mandatory criteria: 1) progressive motor and/or sensory dysfunction consistent with neuropathy in more than one limb with time to nadir between 4 and 8 weeks, 2) electrophysiologic evidence of demyelination in at least two nerves, 3) no other etiology of neuropathy, and 4) no relapse on adequate follow-up. Supportive criteria included high spinal fluid protein level (>55 mg/dL) and inflammatory cells in the nerve biopsy. A diagnosis of “probable SIDP” required progression of demyelinating neuropathy over a 4- to 8-week period. Results: Sixteen definite SIDP patients were identified among 29 probable SIDP patients. An antecedent infection was found in 38% of cases. The two most common neuropathy types were a symmetric motor–sensory neuropathy and a pure motor neuropathy. Cranial nerve deficits and respiratory failure were rare. Spinal fluid protein was high in 93% of cases. Demyelination was documented by the motor nerve conduction in 88% of cases and by the near-nerve needle sensory nerve conduction in two cases. Almost all patients were treated with prednisone and some with additional immunotherapies. Complete recovery was achieved in 69% of cases and partial recovery in others. Definite SIDP had all the characteristics of CIDP with three exceptions: a higher rate of antecedent infection, no relapse rate, and a high rate of recovery to normal. Conclusion: Subacute inflammatory demyelinating polyneuropathy is a definite entity bridging the gap between Guillain–Barre syndrome and chronic inflammatory demyelinating polyneuropathy.

Motor involvement by varicella zoster virus (VZV) in the extremities is relatively rare and may be due to the extension of inflammation to the anterior horn or anterior motor roots.1 In this study we observed conduction block of the peripheral nerves and lesions in the right upper extremity on MRI in a patient with VZV infection. A 64-year-old woman noticed swelling of her right index finger followed by dysesthesia, reddening of the skin, and vesicle in the area from the right shoulder to the palm. She was diagnosed with herpes zoster and treated with acyclovir IV. She had been treated for chronic myelocytic leukemia (CML, chronic stage) since 1992. Four weeks later she noticed weakness of her right upper extremity that progressed slowly. She was admitted to our hospital 2 months later. Physical examination revealed pigmentation of skin in the right C6 and C7 dermatomes. Cranial nerves were intact. Manual muscle testing revealed weakness in the right upper extremity, which did not correspond to individual myotomes: deltoid (4/5), biceps (4/5), brachioradialis (4/5), triceps (3/5), extensor …

A 75-year-old man had noticed muscle atrophy and weakness of his right hand and forearm at the age of 25. The symptoms slowly progressed and then stopped. Right hand tremor appeared at about age 40. There was no symptom in his left upper extremity, and his gait was normal. He now shows severe muscle atrophy in his right hand and forearm. There was distally dominant weakness of the right upper extremity and his hand grip was 0 kg on the right and 25 kg on the left. On admission there was no weakness in the bilateral lower extremities. He had postural tremor in both hands and fingers. The tendon reflexes were hypoactive in the upper extremities and normal in the lower extremities. Abnormalities in the superficial sensation were unremarkable, whereas vibration sensation in both the upper and lower extremities was mildly disturbed. Electromyography revealed chronic denervation, especially in the right upper extremity. The sensory nerve conduction study results and somatosensory evoked potentials in the upper extremities were normal. Cervical MRI demonstrated spondylotic changes, canal stenosis from the C5 to C7 levels, and compression of the spinal cord. His hand tremor was dominant on the right with a peak frequency of about 7 Hz. Tremor frequency and power were decreased by mechanical load. Hirayama's disease (juvenile muscular atrophy of unilateral upper extremity) was the most probable diagnosis, although aging might have produced various additional abnormalities. The tremor seen in this patient showed characteristics of enhanced physiological tremor.

Background: We investigated the effect of age on nerve conduction parameters with special reference to the compound muscle action potential (CMAP) duration and duration ratio. Method: We examined 295 subjects (aged 15–85 years old) with no previous history or present signs of peripheral neuropathy. The subjects were divided into 3 groups: young (15–34 years old); intermediate (35–64 years old), and old (65–85 years old). Results: CMAP amplitude was lower in the old group than in the young group; however, the CMAP ratio (proximal CMAP/distal CMAP) did not change with age. The CMAP duration and duration ratio did not differ among the 3 groups. The CMAP area was smaller in the old group, but the area ratio was almost constant among the 3 groups. Conclusion: We suggest that age-related changes in CMAP amplitude, duration or area may occur uniformly, at least in the forearm and the calf segment, in routine nerve conduction studies. The present findings also provide useful and reliable information, regardless of age, in diagnosing peripheral neuropathy.