We report the case of somatosensory evoked potential loss during a transforaminal interbody fusion during exposure following a transient rise in blood pressure. The topography of signal loss and elimination of technical causes led to the inference of left sided stroke which was confirmed as a left thalamocapsular hemorrhagic infarct on postoperative magnetic resonance imaging. Use of intraoperative neuromonitoring in this lumbar fixation surgery helped to identify it intraoperatively and prevented undue alternative surgical decision making.

The pathogenesis of many strokes originates in the vessel wall. Despite this, most traditional imaging focuses on the vascular lumen. Vessel-wall magnetic resonance imaging (VWMRI) is useful for establishing the etiology of intracranial stenosis. It also provides information regarding atherosclerotic plaque composition and thus plaque vulnerability, which is an indication of its potential to cause a stroke. In this review we focus on the characteristics of VWMRI findings in various arteriopathies related to intracranial artery stenosis, and discuss the clinical implications of these findings.

Citations

• Intracranial Atherosclerotic Stenosis
  Jeong Yoon Song, Sun U. Kwon
  Cerebrovascular Diseases Extra.2025; 15(1): 62.     CrossRef
• The Role of High-Resolution Magnetic Resonance Imaging in Cerebrovascular Disease: A Narrative Review
  Xiaohui Li, Chengfang Liu, Lin Zhu, Meng Wang, Yukai Liu, Shuo Li, Qiwen Deng, Junshan Zhou
  Brain Sciences.2023; 13(4): 677.     CrossRef
• Acute Stroke Caused by Large Vessel Vasculitis in a Patient with Systemic Lupus Erythematosus
  Min A Lee, Byoung Wook Hwang, Dong Kun Lee, Chang Ju Lee, Ju Hye Kim, Seong Hwan Ahn
  Journal of Neurosonology and Neuroimaging.2022; 14(1): 51.     CrossRef
• Vessel Wall Magnetic Resonance Imaging in Cerebrovascular Diseases
  Federico Mazzacane, Valentina Mazzoleni, Elisa Scola, Sara Mancini, Ivano Lombardo, Giorgio Busto, Elisa Rognone, Anna Pichiecchio, Alessandro Padovani, Andrea Morotti, Enrico Fainardi
  Diagnostics.2022; 12(2): 258.     CrossRef

Transient global amnesia is a syndrome of temporary loss of short-term memory and is not accompanied by any other neurological deficit. Diffusion-weighted imaging is useful to improve the diagnostic accuracy of transient global amnesia. We report a 68-year-old woman with multiple lesions on diffusion-weighted imaging in the right corpus callosum and left hippocampus. To the best of our knowledge, this is the first case of a diffusion-weighted imaging lesion in the body portion of the corpus callosum.

Background: Moyamoya disease is characterized by a progressive stenosis or occlusion of the intracranial internal carotid artery and/or the proximal portion of the anterior cerebral artery and middle cerebral artery. Whether the onset time was childhood or adulthood, the bony carotid canal diameter might be different, but reflects the size of internal carotid artery passing through the bony carotid canal. In this study, we aimed to identify the relationship between bony carotid canal diameter and clinical manifestation. Methods: 146 consecutive patients diagnosed with moyamoya disease by brain imaging studies were included. We measured the diameter of a transverse portion of bony carotid canal on bone window of a brain computed tomography(CT) image. Patients were divided into two groups, ischemic or hemorrhagic stroke according to clinical manifestation. As a result, 115 patients were included. The Suzuki stage was used as criteria for disease progression. Results: Bony carotid canal diameter was 3.6 ± 0.5 (right) and 3.6 ± 0.4 (left) in the hemorrhagic stroke group, and 3.7 ± 0.4 (right) and 3.6 ± 0.4 (left) in the ischemic stroke group. The bony carotid canal diameter of the moyamoya vessels (3.6 mm) was smaller than the diameter of non-moyamoya vessels (3.8 mm), significantly (p = 0.042). However, there was no difference in the collateral patterns and clinical manifestation in a comparison of both groups. Conclusions: In our study, there was no significant difference of clinical manifestations and collateral patterns depend on the bony carotid canal diameter in patients with moyamoya disease. These findings suggest that the clinical presentations of moyamoya disease are not related to the onset time of the disease.

Background
Neuromodulation therapy has been used to an adjunctive treatment promoting motor recovery in stroke patients. The objective of the study was to determine the effect of repetitive transcranial magnetic stimulation (rTMS) on neurobehavioral recovery and evoked potentials in rats with middle cerebral artery occlusion. Methods: Seventy Sprague-Daley rats were induced permanent middle cerebral artery occlusion (MCAO) stroke model and successful stroke rats (n=56) assigned to the rTMS (n=28) and sham (n=28) group. The 10 Hz, high frequency rTMS gave on ipsilesional forepaw motor cortex during 2 weeks in rTMS group. The somatosensory evoked potential (SSEP) and motor evoked potential (MEP) were used to evaluate the electrophysiological changes. Behavioral function of the stroke rat was evaluated by the Rota rod and Garcia test. Results: Forty rats (NrTMS=20; Nsham=20) completed all experimental course. The rTMS group showed better performance than sham group in Rota rod test and Garcia test at day 11 (p<0.05) but not day 18 (p>0.05). The amplitude of MEP and SSEP in rTMS group was larger than sham group at day 18 (p<0.05). Conclusions: These data confirm that the high frequency rTMS on ipsilesional cerebral motor cortex can help the early recovery of motor performance in permanent middle cerebral artery stroke model and it may simultaneously associate with changes in neurophysiological activity in brain.

Citations

• A C-shaped miniaturized coil for transcranial magnetic stimulation in rodents
  Wenxuan Jiang, Robert Isenhart, Charles Y Liu, Dong Song
  Journal of Neural Engineering.2023; 20(2): 026022.     CrossRef
• Effects of high‐frequency repetitive transcranial magnetic stimulation (rTMS) on spontaneously hypertensive rats, an animal model of attention‐deficit/hyperactivity disorder
  Jungyun Kim, Heamen Park, Seong‐lan Yu, Sungju Jee, Keun‐Ah Cheon, Dong Ho Song, Seung Jun Kim, Woo‐Young Im, Jaeku Kang
  International Journal of Developmental Neuroscienc.2016; 53(1): 83.     CrossRef

A 77-year-old man developed acute vertigo and unsteady gait. Neurological examination revealed spontaneous left-beating nystagmus in the primary position. He fell to the left when walking without support. Magnetic resonance imaging showed an acute infarction involving the right parieto-temporal lobe. Although the vertigo and unsteady gait are most often associated with vestibular disorders involving the infratentorial structures, those may occur in cerebral infarction of the parieto-temporal lobe.

Background
It is generally accepted that upper motor neuron (UMN) lesion can alter lower motor neuron (LMN) functionby the plasticity of neural circuit. However there have been only few researches regarding the axonal excitability of LMNafter UMN injury especially during the acute stage. The aim of this study was to investigate the nerve excitability propertiesof the LMNs following an acute to subacute supratentorial corticospinal tract lesion. Methods: An automated nerve excitabilitytest (NET) using the threshold tracking technique was utilized to measure multiple excitability indices in median motoraxons of 15 stroke patients and 20 controls. Testing of both paretic and non-paretic side was repeated twice, during theacute stage and subacute stage. The protocols calculated the strength-duration time constant from the duration?릀harge curve,parameters of threshold electrotonus (TE), the current-threshold relationship from sequential sub-threshold current, and therecovery cycle from sequential supra-threshold stimulation. Results: On the paretic side, compared with the control group,significant decline of superexcitablity and increase in the relative refractory period were observed during the subacute stageof stroke. Additionally, despite the absence of statistical significance, a mildly collapsing in (

Transcranial Doppler(TCD) is an important diagnostic tool for evaluating the patients with stroke. It has some advantages and unique role when compared with other neuroimaging modalities. Recent development f transcranial color-coded Doppler(TCD) improves the limitation and pitfalls of TCD. The current indications of TCD are as follows: 1. Screening and evaluation of the intracranial major vessels 2. early detection and follow-up of vasospasm due to SAH 3. emboli detection (high-imtensity transient signals, HITs) 4. dignosis and follow-up of subclavian steal 5. evaluation of intracranial collaterals when the extracranial ICA has severe stenosis or occlusion 6. evaluation of cerebral perfusion pressure (intracranial pressure) 7. evaluation of arteriovenous malformation 8. diagnosis and follow-up of arterial dissenction 9. diagnosis and follow-up of venous sinus thrombosis (experimental)

Background
and Objectives: The Motor evoked potentials (MEP) study may be useful in the evaluation of the degree of impairment in the motor nervous system and in the determination of the prognosis. The purpose of this study is to evaluate the status of central nervous system in acute and subacute state of cerebral ischemia by comparing the changes of MEP I the initial and follow-up study. Methods: Twenty patients with hemiparesis caused by ischemic stroke were recruited for this study. We tested MEP within 7 days and follow-up after 14 days after symptoms onset. The cerebral motor cortex area, cervical area for upper extremity and lumbar area for lower extremity were stimulated by transmagnetic stimulator. The central motor conduction time(CMCT) was measured with the difference in MEP caused by stimulating the vertical area and spinal area. The CMCT of hemiparetic patients were classified into three group-normal, delayed, and no evoked MEP groups. Results : The CMCT in hemiparetic side of acute ischemic stroke patients were significantly delayed (P < 0.05) compared with the control group. The CMCT of hemiparetic side in the follow-up study showed no significantly difference in comparison to the control group. The prognosis of motor improvement was better I the groups of delayed MEP than the groups of no evoked MEP. Conclusion : The CMCT of hemiparetic and contralateral sides were delayed in acute ischemic stroke, compared with control group and were returned to normal boundaries in subacute state, But in the most cases with no MEP response in the initial study, also showed no MEP response in the follow-up study. The recovery occurred in the subacute state in cases with mild hemiparesis, whereas recovery did not occur in the subacute stage in case with severe hemiparesis.

Background
: Tremor is uncommon manifestation of stroke. Therefore a few cases have been reported until now. There is still uncertainly about the characteristics of post-stroke tremor. Furthermore the pathogenesis and responsible structures of post-stroke tremor are not precisely known. We have recently experienced 34 cases of post-stroke tremor for the past 6 years. We analysed the clinical features and electrophysiologic findings of post-stroke tremor to evaluate the general characteristics and to analogize the possible pathogenetic mechanisms of post-stroke tremot. Methods : The clinical characteristics of post-stroke tremor were summarized in according to the onset time, involved body parts, types, tremor frequencies, neuroradiologic findings, and associated symptoms. The tremor frequencies were recorded by using a gyroscope. The spectral analysis of tremor frequencies were done automatically with Motus I software. Results : Tremor onset were remarkably varied. Some patients showed a tremor appearing at the onset of a stroke and other patients showed delayed-onset tremor 10 years after a stroke. Tremor frequencies were also much varied. The range of hand tremor frequencies were from 1.5 to 12Hz. Lesions were found in 31 cases (infarction 27, hemorrhage 4) on neuroimaging. In the cases of cerebral infarctions, 7 cases showed multiple small vessel disease and 20 cases showed cerebral vessel lesions. The most commonly involved cerebral vessel lesion was the middle cerebral artery territory. Several different clinical patterns of post-stroke tremor were identified. Conclusions : There are some evidences fro the data summarized here to suggest that several pathogenetic mechanisms including central oscillators could be involved for the development of tremors and that tremor generating neural circuits.

It has been said that variable anatomical structures and neural circuits are related to the generation of tremor. There are cerebral cortex, thalamus, basal ganglia, inferior olivary nucleus, midbrain tegmentum, stretch reflex, and musculoskeletal structures. The stretch reflex is related with the physiologic tremor and various peripherally originated tremors. We experienced a case with the post-stroke resting tremor which was induced and aggravated by mechanical stretching stimulation. In the present case, stretch reflex has a major role in the generation and exacerbation of tremor. It is presummed that the development of tremor is attributed to the increased rhythmicity of ventral intermedius nucleus of thalamus. The enhancement of thalamic rhythmicity may be due to the increasement of long latency reflex by post-stroke rigidity. This case suggests that stretch reflex may have a major role in the pathophysiologic mechanism of a certain centrally originated tremor.

Stroke remains a leading cause of death and disability. New rehabilitation therapies and approaches hold the promise of reducing the disability caused by stroke. Following stroke, the pattern of deficits and recovery, associated medical problems, and psychosocial factors vary among individuals, and it becomes critical to individualize rehabilitation program. Awareness of the pathophysiology and recovery patterns following stroke and attention to detail in medical and rehabilitative management enhance current functional outcome. The issues of when rehabilitation should begin, and what role rehabilitation should play acutely after stroke are changing rapidly. Based on studies demonstrating superior outcomes in programs that combine acute and rehabilitative care beginning immediately after stroke, many hospitals are developing practice protocols that require rehabilitation consultation and screening within 24 hours after stroke onset.

Dyskinesia con occur as a neurological abnormality due to stroke, and its incidence in stroke patients is reported be about 1%. It is possible to classify dyskinesia into one of the morphologic types already classified clinically. However, a specific type of dyskinesia can occur, one which does not fall into the existing morphologic types. We experienced sych a case of specific type dyskinesia, which couldn't be classified into the existing classification system. A 50-year-old man visited our hospital due to rhythmic dyskinesia of the right hand, which appeared during the resting state, and had developed one month after left subcortical infarction. Flexion and extension movements of the fingers at 3Hz appeared due to the impulse to move, however, this abnormal movement could be easily suppressed under the patients will. We suggested that the abnormal movement was similar to akathisia from the fact that if occurred due to the internal desire to move and that the patient could suppress dyskinesia. However, the rhythmic tendency and lack of medication history of antipsychotics suggested that the movement was not the typical form of akathisia. The present case may represent a new clinical type of movement disorder developed after stroke. Considering the clinical pattern of the present case and following a review of the literature, we believe that it can be labeled, post-stroke rhythmic akathisia.

The MELAS (Mitochondrial Encephalomyopathy with Lactic Acidosis, and Stroke-like episodes) syndrome is one of the inherited mitochondrial disorder. We have experienced a 16-year-old girl with headaches and left hemianopsia. Diagnosis of MELAS syndrome with multiple brain parenchymal lesions was confirmed by gene study. The stroke-like lesion of MELAS syndrome showed significant improvement in radiological follow up study. Therefore, MRI findingsin MELAS could be interpreted as metabolic cellular dysfunction rather than ischemic vasculopathy

Background
: Changes in firing pattern and in the recruitment order of single motor unit(MU) have been claimed tobe characteristic of central motor lesions, and a reduced firing rate was found in upper motor neuron lesions. But thesefindings have been rarely studied before in Korea, so we studied initial MU recruitment pattern in stroke patients withhemiparesis.Methods : We studied six patients(3 men and 3 women) whose mean age was 60.6