Intraexaminer Variability of Nerve Conduction Study in Healthy Person

BACKGROUND: Nerve conduction study (NCS) is an objective and quantitative test in evaluating peripheral nerve disorders. Several physiological and technical factors are well known to influence the results of NCS, which can be controlled and regulated by standardization of environment and through the process to make range of normality. However, most electromyographers do not pay much attentions about inter- and intra-examiner variabilities, and there are only a few and incomplete reports on these topics. We examined the intra-examiner variability of NCS on the basis of periods of practice. METHODS: Twenty-eight electromyographers were divided into two groups: residents and neurologist-technicians. All, having variable NCS training periods, have performed NCS on one of other 27 electromyographers ten times within two weeks where each study was made once a day. RESULTS: Coefficient of variation and external quotient increased according to the following order - nerve conduction velocities (NCV), terminal latencies (TL), and amplitudes of compound action potentials (AMP). There were significant differences between the two groups in NCV and TL, but no statistical difference in AMP. CONCLUSIONS: Our results suggest that errors from intra-examiner variability should be considered when interpreting NCS and that those electromyographers who have enough training should perform NCS.

Asymptomatic electrophysiologic carpal tunnel syndrome in diabetics: entrapment or polyneuropathy

Electrophysiologic carpal tunnel syndrome (CTS) is common and is frequently asymptomatic in diabetics. In order to evaluate the clinical significance of asymptomatic electrophysiologic CTS, the nerve conduction studies (NCS) of 48 diabetics with asymptomatic electrophysiologic CTS were compared with those of 56 age and gender-matched controls, as well as 50 patients with symptomatic CTS without diabetes. Nerve conduction velocities of the ulnar, peroneal, and posterior tibial nerves were significantly slower in diabetics with asymptomatic electrophysiologic CTS than in normal controls. Compared to symptomatic non-diabetic CTS, there was also significant slowing of the median and ulnar nerve conduction velocities in asymptomatic diabetic CTS. However, in diabetics with asymptomatic CTS, abnormalities of the distal segment of the median NCS were more prominent compared with those of all the other tested nerves. These findings suggested that asymptomatic electrophysiologic CTS in diabetics is a manifestation of increased vulnerability to the entrapment of the peripheral nerve.

A Case of Primary Lymphoma Presenting as Cauda Equina Syndrome

Primary CNS lymphoma (PCNSL) which is localized in the cauda equina of the spinal cord is very rare. A 75-year-old man had pain in both legs and gait disturbance for the last 45 days. Painful paresthesia and weakness in both legs worsened during a one month period and he was unable to stand up by himself. In a physical examination, lym-phadenopathy nor organomegaly was found. A neurological examination revealed a dominantly proximal muscle weak-ness of the lower extremities. All modalities of sensation were decreased in both legs and a Romberg test was found positive. A CSF cytology demonstrated a large B-cell lymphoma. Following an extensive evaluation of the patient, the lymphoma was found to be limited in the cauda equina. The patient was treated with systemic dexamethasone. After the treatment, his symptoms were improved and a follow up lumbar spine MRI showed shrunken cauda equina lesions.

The usefulness of standardization of the nerve conduction study in the diagnosis and follow up of the demyelinating polyneuropathy

BACKGROUND: Nerve conduction study is an objective and quantitative diagnostic method for the diagnosis and follow-up study of polyneuropathy. Sometimes it is hard to interpret the nerve conduction study, because there are many segmental variables to test and uneven distribution of abnormalities in polyneuropathy. And there can be some interpersonal differences in the interpreting the results. It is obvious that one objective and quantitative value that represents the many segmental variables is helpful for the clinical interpretation and follow?up of polyneuropathy. METHODS: We evaluated 242 normal subjects and 71 patients with demyelinating polyneuropathy to find out a standardized representative value, distinguishing patients from normal subjects. The standardized representative value was made by combination of the some standardized segmental variables which showed marked differences between two groups. We evaluated the clinical usefulness of this value by comparing the sequential changes of this value with the clinical course. RESULTS: Statistically significant differences were present in each segmental value of the nerve conduction study between the groups of patients and normal persons. The diagnostic sensitivity of the segmental value was in range of 25.7%-81.8% in case of 2SD criteria. The diagnostic sensitivity of each functional standardized value - average of the segmental standardized values of same nature - was in range of 54.1%-89.9% in case of 2SD criteria. Using 3SD criteria the sensitivity was reduced to 20.9%-81.1%, more in sensory and mixed nerve than motor nerve. By combination of these functional standardized values, the diagnostic sensitivity could increase up to 79.1%-93.2% on 3SD criteria. CONCLUSION: The best combination which represents the NCV study is the average of the motor nerve terminal latency, the motor nerve conduction velocity, and the ratio of conduction block with 93.2% sensitivity and 100% specificity. This representative value well reflects the clinical course of patient in follow-up studies.

Paraesthesia on hand and foot

No abstract available.

A Case of Paraganglioma Presenting as Stroke

Paraganglioma is a pheochromocytoma arising from chromaffin cells in peripheral ganglia and extremely rare. Although pheochromocytoma occurs only in approximately 0.1% of the hypertensive population, it has the significance since it is a curable disease. Pheochromocytoma shows variable symptoms of anxiety, headache, precordial and epigastric distress, blanching of the extremities, perioral pallor, shortness of breath, tachycardia, palpitation, nausea or vomiting, and dizziness besides persistent or paroxysmal hypertension. Few cases of cerebral infarct or hemorrhage have been reported also. There has been no report of lacunar infarct caused by paraganglioma in this country since it occurs rarely. Here we shall report a case of paraganglioma with ataxic hemiparesis.

Monitoring of Heparin Treatment in Acute Cerebral Infarction

Althought there are controversies regarding the appropriate dosage and the best monitoring method, heparin is the most widely used anticoagulant. Recent reports indicate that continuous infusion appears safer and is as effective as interrnittent intravenous infusion in. thromboembolic diseases. The therapeutic arnount has been determinated on the assumption of lowest of thrombosis and bleeding. However, several studies indicate that standardized doses of heparin can induce unpredictable anticoagulation in some patients. Recently, a new method for measuring the plamsma heparin concentratiOn using a chromogenic substrate is available. We designed this study to evaluate the accuracy of aPTT in the monitoring of heparin therapy and define the appropriate dosage and rnethods for infusion in patients with acute cerebral infarction. Among the patients with acute cerebral infarction and admitted to neurology department from June 1989 to December 1989. 13 patients were enrolled. They were divided into two groups according to the heparin dosage and using bolus infusion or not. Group 1 included 6 patients(4 men, 2 women) treated with 5,000 unit bolus IV followed by contionus infusion of 15.000 unit./day. Group 2 included 7 pa tients(5 men. 2 women) treated with contionus infusion of 10.000 unit/day. Their mean age were 55.2 and 60.1 years oId respectivelv. We measured the baseline plasma heparin level. aPTT, antithrombin-III and platelet and 1 24 48 96 and 120 hours after starting therapy. The mean of the aPTT and heparin concentration of 1, 24 hour after infusion of the group 1 increased markedly near to the 3 times of control value. But the all value of the group 2 remained constratly in therapeutic range during the study. The best method of heparin administration to maintain an effective therapeutic range is continous intravenous infusion. The results of this study indicate that treatment of acute cerebral infarction with continous intravenous infusion of 10000 unit/day of heparin is more effective and safer than bol.

Three Cases of Progressive Supranuclear Palsy

Progressive supranuclear palsy (PSP) is a kind of chronic neurodegenerative diseases, the main clinical characteristics of which are loss of voluntary control of vertical gaze, particularly downgaze, dysarthria. Diffuse body rigidity with dystonic extension of the peck, and dementia In its earlier stages, PSP can be misdiagnosed as Parkinson's disease because of lack of awareness of the disease and symptoms and signs may not be diagnostic until the disease is advanced. About 4% of all patients with parkinson's disease turn out eventually to have progressive supranuclear palsy. We report the three cases of PSP with MRI brain scan.

Early-Onset Parkinson's Disease

Between 1986 and 1990, nine patients with early-onset Parkinson's disease were examined in the Neurologic Clinic of Yongdong Severance Hospital, Yonsei University College of Medicine. The incidence of the disease was 3.9% of the total patients(228 cases) of Parkinson's disease. All except one were sporadic. There were 4 men and 5 women. Their ages of onset ranged from 27 to 39 years(mean, 33.9 years), but none with onset before 21 was seen in this study. The intervals between initial symptoms and establishing the diagnosis ranged from 1 to 9 years(mean, 4.4 years). The initial symptoms were tremor(55.6%). Gait disturbance(33.3%), and weakness. The most frequent clinical findings of early-onset Parkinson's disease displayed no significant differences from those of adult-onset Parkinson's disease. None had autonomic dysfunction, dementia, dystonic phenomenon,or marked diumal fluctuation. According to the modified Hoehn and Yahr's classification. 1 case were in stage I, 5 in stage II, 2 in stage m. and 1 in stage IV. All patients responded initially to levodopa(Sinemet). But 2 patiens showed early appearance of levodopa related abnormal involuntaly movements.

Three Cases of Opsoclonus

Opsoclonus introduced in 1913, by Orzechowski is a disorder of eye movements charactenzed by involuntary bursts of multidirectional saccades without an intersaccadic Interval and persistulg during sleep, is often accompained by myoclonic jerks of the face and body. It is a rare condition, the common causes of which are viral encephalitides and a paraneoplastic manifestation of an occult malignant neoplasm The sites of the responsible lesion, however, hez been a matter of controversy; cerebellum midbrain, thalamus, thalamus and midbrain, has been suggested, as well as a combination of several sites in the central nervous system We present three cases of opsoclonus with brief review of literatures. The first and second case, suspected vural infection, presented with prodromal symptoms(fever, headache, sore throat), ataxia and opsoclonus. Clinical manifestations improved with clonazepam therapy, Tbe thlrd case is 9 month old male presented with vomiting, inguinal hernia, opsoclonus and poor nutrition. The brain CT scan revealed tumor at pons and midbrain.