• Annals of Clinical Neurophysiology
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• v.2 no.2
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• pp.81-88
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• 2000

Background : Guillain-$Barr{\acute{e}}$ syndrome(GBS) is characterized clinically by acute flaccid paralysis, areflexia, and albumino-cytologic dissociation. Based on electrophysiology and pathology, GBS can be divided into either predominantly demyelinating or predominantly axonal patterns. Objectives : The clinical and laboratory status of probable acute axonal GBS occurring at a mental hospital was evaluated. Methods : Eight schizophrenia patients with probable acute axonal GBS were analyzed. Results : The mean age of the patients was 38 years old. Most of the patients were men. All patients showed an acute ascending paraparesis and/or quadriparesis with areflexia, and all have a history of schizophrenia for 3~20 years. The diseases occurred predominantly in the summer and electrodiagnostic studies revealed axonal patterns. The patients were treated by supportive care, except one patient with intravenous immunoglobulin. The prognosis was improved in 3 ; no change in 4 and 1 became aggravated. One patient with acute motor-sensory axonal neuropathy had a recurrence after 10 months of the first attack. Conclusions : Axonal GBS has been considered uncommon clinically or electrophysiologically, but 8 probable acute axonal GBSs occurring at a mental hospital have been diagnosed in 3.5 years.

• Annals of Clinical Neurophysiology
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• v.1 no.2
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• pp.160-167
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• 1999

Although somatosensory evoked potentials(SSEPs) have been utilized as the useful diagnostic tools in evaluating the wide variety of pathological conditions, such as focal lesions affecting the somatosensory pathways, demyelinating diseases, and detecting the clinically occult abnormality, their neural generators is still considerably uncertain. To appreciate the basis for uncertainties about the origins of SSEPs, consider criteria that must be met to establish a causal relationship between activity in a neural structure and a spine/ scalp-recorded potential. Electrode locations and channel derivations for SSEPs recordings are based on two principles:(1) the waveforms are best recorded from electrode sites on the body surface closest to the presumed generator sources along the somatosensory pathways, and(2) studies of the potential-field distribution of each waveform of interest dictate the best techniques to be used. In this article, authors will describe followings focused on ;(1) the concepts of near field potentials(NFPs) and far field potentials(FFPs) - the voltage of NFPs is highly dependent upon recording electrode position, FFPs are unlike NFPs in that they are widely distributed, their latencies and amplitudes are independent of recording electrode.(2) appropriate montage settings to detect the significant potentials in the median nerve and posterior tibial nerve SSEPs(3) neural generators of various potentials(P9, N13, P14, N18, N20, P37) and their clinical significance in interpretating the results of SSEPs. Especially, Characteristics of N18(longduration, small superimposed inflection) suggested that N18 is a complex wave with multiple generators including brainstem structures and thalamic nuclei. And N18 might be used as the parameter of braindeath. Precise understanding on these facts provide an adequate basis utilizing SSEPs for numerous clinical purposes.

• Journal of Korean Neurosurgical Society
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• v.41 no.6
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• pp.359-366
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• 2007

Trigeminal neuralgia is a condition associated with severe episodic lancinating facial pain subject to remissions and relapses. Trigeminal neuralgia is often associated with blood vessel cross compression of the root entry zone or more rarely with demyelinating diseases and occasionally with direct compression by neoplasms of the posterior fossa. If initial medical management fails to control pain or is associated with unacceptable side effects, a variety of surgical procedures offer the hope for long-lasting pain relief or even cure. For patients who are healthy without significant medical co-morbidities, direct microsurgical vascular decompression [MVD] offers treatment that is often definitive. Other surgical options are effective for elderly patients not suitable for MVD. Percutaneous retrogasserian glycerol rhizotomy is a minimally invasive technique that is based on anatomic definition of the trigeminal cistern followed by injection of anhydrous glycerol to produce a weak neurolytic effect on the post-ganglionic fibers. Other percutaneous management strategies include radiofrequency rhizotomy and balloon compression. More recently, stereotactic radiosurgery has been used as a truly minimally invasive strategy. It also is anatomically based using high resolution MRI to define the retrogasserian target. Radiosurgery provides effective symptomatic relief in the vast majority of patients, especially those who have never had prior surgical procedures. For younger patients, we recommend microvascular decompression. For patients with severe exacerbations of their pain and who need rapid response to treatment, we suggest glycerol rhizotomy. For other patients, gamma knife radiosurgery represents an effective management strategy with excellent preservation of existing facial sensation.

• Annals of Clinical Neurophysiology
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• v.25 no.2
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• pp.84-92
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• 2023

Background: Clinical spectrum of immunoglobulin M (IgM) monoclonal gammopathy varies from IgM monoclonal gammopathy of unknown significance (IgM-MGUS) to hematological malignancies. We evaluated the clinical features, electrophysiological characteristics, and prognosis of patients with peripheral neuropathy associated with IgM monoclonal gammopathy (PN-IgM MG). Methods: We retrospectively evaluated 25 patients with PN-IgM MG. Peripheral neuropathy was classified as axonal, demyelinating, or undetermined, based on electrophysiological studies. We classified the enrolled patients into the IgM-MGUS and malignancy groups, and compared the clinical and electrophysiological features between the groups. Results: Fifteen patients had IgM-MGUS and 10 had hematologic malignancies (Waldenström's macroglobulinemia: two and B-cell non-Hodgkin's lymphoma: eight). In the electrophysiological evaluation, the nerve conduction study (NCS) criteria for demyelination were met in 86.7% of the IgM-MGUS group and 10.0% of the malignancy group. In particular, the distal latencies of the motor NCS in the IgM-MGUS group were significantly prolonged compared to those in the malignancy group (median, 9.1 ± 5.1 [IgM-MGUS], 4.2 ± 1.3 [malignancy], p = 0.003; ulnar, 5.4 ± 1.9 [IgM-MGUS], 2.9 ± 0.9 [malignancy], p = 0.001; fibular, 9.3 ± 5.1 [IgM-MGUS], 3.8 ± 0.3 [malignancy], p = 0.01; P-posterior tibial, 8.3 ± 5.4 [IgM-MGUS], 4.4 ± 1.0 [malignancy], p = 0.04). Overall treatment responses were significantly worse in the malignancy group than in the IgM-MGUS group (p = 0.004), and the modified Rankin Scale score at the last visit was higher in the malignancy group than in the IgM-MGUS group (2.0 ± 1.1 [IgM-MGUS], 4.2 ± 1.7 [malignancy], p = 0.001), although there was no significant difference at the initial assessment. Conclusions: The risk of hematological malignancy should be carefully assessed in patients with PN-IgM MG without electrophysiological demyelination features.

• Journal of the Korean Society of Radiology
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• v.81 no.1
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• pp.243-247
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• 2020

We report a rare case of hyperglycemia-related osmotic demyelination syndrome (ODS) with focus on the imaging findings. A 61-year-old man with diabetes was admitted for general weakness and severe thirst. A few days later, he complained of dysarthria, dysphasia, and dysmetria. Laboratory examinations showed significant hyperglycemia, but normal electrolyte levels. Brain MRI revealed T2-signal abnormalities that were symmetrical, non-space occupying, and located in the central pons with a peripheral sparing pattern, which were suggestive of ODS. In addition, subsequent MRI revealed progression of signal hyperintensity; however, the patient's symptoms improved.