Showing papers by "Hyun Goo Kang published in 2022"

Anti-NMDAR encephalitis with bilateral basal ganglia MRI lesions at a distance of time: a case report

Abstract: Approximately half (55%) of anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is known to show abnormal brain images, including high signal intensity in T2 or fluid attenuated inversion recovery (FLAIR) images. In a minority of anti-NMDAR encephalitis cases, high signal intensity on diffusion-weighted imaging (DWI) has been reported, a finding that is highly suggestive of a stroke.We present the case of a 66-year-old man who experienced two separate focal seizure events, which involved first the right and then the left upper extremity in a short period of time. The patient showed focal clonic seizures involving right arm and hand, which sometimes evolved to bilateral tonic-clonic seizures on his first admission. Brain magnetic resonance imaging (MRI) showed high signal intensity on DWI and low signal intensity on the apparent diffusion coefficient (ADC) map of the left caudate nucleus and putamen. The patient was discharged symptom-free with anti-epileptic drugs for 2 weeks. The second admission occurred 4 days after the discharge. He exhibited a new symptom of focal clonic seizures involving left arm and hand while showing a brain lesion on the opposite side which is hyperintense on DWI image and hypointense on ADC map. The patient was eventually diagnosed with anti-NMDAR encephalitis according to the cerebrospinal fluid (CSF) antibody test.This is the case of anti-NMDAR encephalitis patient whose DWI/ADC images revealed sequential involvement on the left and right basal ganglia with a short time interval. When stroke-like brain lesions on DWI are found in a patient with a focal seizure, a CSF study could help rule out autoimmune encephalitis. We also suggest that DWI/ADC map images may be useful for the early detection of anti-NMDAR encephalitis.

Revised Electroencephalography Terminology and Clinical Consideration

Abstract: Electroencephalography (EEG) has been used for decades to evaluate and assess brain function. It is a useful method to diagnose brain disorders. However, confirmed interpretation of EEG is quite challenging because there is no standardized method for EEG reading and this may lead to interrater variability even among expert electroencephalographers. In this background, uniformly accepted nomenclature for EEG pattern were required to improve interrater agreement and to support communication for EEG research. American Clinical Neurophysiology Society (ACNS) established the standardized critical care EEG terminology since 2012 and has recently published the revised 2021 version of EEG terminology. This review covers new concepts of 2021 ACNS EEG terminology and clinical considerations of various EEG patterns.

Chronic Headache Attributed to Vertebrobasilar Insufficiency

Abstract: Vertebrobasilar insufficiency, a condition characterized by poor blood flow to the posterior portion of the brain, can cause headaches. However, the exact underlying mechanism is not yet fully understood. The patient enrolled in our study reported experiencing intermittent headaches radiating from the left shoulder, similar to chronic tension-type headaches. His aggravated headache and severe left vertebral artery stenosis were detected by brain computed tomography angiography. Stent insertion successfully expanded the patient’s narrowed left vertebral artery orifice. Subsequently, the patient’s headaches improved without recurrence during the one-year follow-up period. In summary, chronic headaches attributed to vertebrobasilar insufficiency in this study, improved after stent insertion to reverse severe left vertebral artery stenosis.

Delayed-onset subdural hematoma after mild head injury with negative initial brain imaging.

Abstract: Mild head injuries are commonly encountered in the neurosurgical field and emergency room (ER). The usual step is to discharge if the mental status of the patient is good and the initial brain computed tomography (CT) findings are normal. Here, we report a rare case of an 82-year-old male patient who developed delayed-onset bilateral subdural hematoma five weeks after a mild head injury. He was not on anticoagulant or antiplatelet therapy. The initial CT scan on the day of injury and magnetic resonance (MR) imaging performed seven days after the injury did not reveal any intracranial pathology or skull fracture. However, he presented with severe headaches and an unsteady ataxic gait five weeks later. Brain CT revealed bilateral subdural hematoma compressing the lateral ventricles with a midline shift to the right side. The possible pathophysiological mechanisms underlying this uncommon entity are discussed with a review of the relevant literature.

Reflex of the Gracilis in Brain Death

Abstract: In patients with brain death, reflex movements originating from spinal reflexes are observed intermittently. Generally, they can occur under hypoxic stimuli such as when the ventilator is removed, under physical stimuli such as bending the neck, or under hypotension. Finger- and toe-jerk responses are commonly observed reflex movements that can occur in patients with brain death. In addition, the Lazarus sign, known as the most dramatic reflex movement, appears mainly in the upper extremities (e.g., the hands and arms) and in the distal lower extremities (e.g., the soles and toes). This case showed a reflex movement that was triggered by the contraction of the gracilis, a proximal muscle in the lower extremities, with only a gentle stimulus on the sole.

Hemorrhagic Transformation after Intravenous Tissue Plasminogen Activator Administration in Acute Distal Middle Cerebral Artery Occlusion

Abstract: Atrial fibrillation and cerebral embolism are known to increase the risk of hemorrhagic transformation (HT). In addition, a sufficient number of collateral vessels in acute ischemic stroke can maintain the ischemic penumbra and prevent progression to the ischemic core, while an insufficient number of collateral vessels increase the HT risk after therapeutic recanalization. In this case, when the middle cerebral artery is recanalized, reperfusion injury may occur in the basal ganglia due to insufficient collateral vessels.

Rapid Regression of Carotid Artery Stenosis Shortly after Intensive Medical Therapy

Abstract: Carotid artery stenosis (CAS) is mainly caused by atherosclerosis. Intensive medical therapy is effective in preventing stroke in CAS. To date, there has been no published report of rapid regression of CAS. A woman with untreated hyperlipidemia visited our emergency room with left hemiparesis. She exhibited facial palsy, left hemiparesis, and dysarthria immediately after the visit. Brain magnetic resonance (MR) diffusion-weighted imaging confirmed acute infarction in the right middle cerebral artery (MCA) territory due to severe stenosis of the right internal carotid artery (ICA), which was revealed by MR angiography and carotid duplex ultrasonography. The patient started intensive statin therapy and dual antiplatelet agent therapy. Carotid artery stenting was not performed until hospitalization day 16 due to pleural effusion. On day 16, digital subtraction angiography was performed, and spontaneous regression of severe stenosis was observed. Only mild stenosis with ulcerative plaque was evident. The rapid CAS regression in this case may be caused by M2 macrophage polarization as a result of intensive statin therapy. This rapid regression may also result from reduced foam cell formation by statin and aspirin and thereby increased endogenous thrombolysis. Our patient demonstrated the efficacy of short-term intensive statin and aspirin therapy on atherosclerosis with untreated hyperlipidemia.

Incidental accumulation of Technetium-99m pertechnetate in subacute cerebral infarction: A case report

Abstract: BACKGROUND When interpreting nuclear medicine images, unexpected findings are sometimes encountered. Recognizing these findings and determining the mechanism of their occurrence could have a significant impact on early diagnosis of critical diseases and the appropriate management of patients. CASE SUMMARY A 59-year-old man was admitted to the emergency room due to left hemiparesis, left hemifacial palsy, and mild dysarthria. After 2 wk of hospitalization, the patient complained of dry eyes and mouth. Thus, salivary scintigraphy was performed to evaluate the functional status of his salivary glands. Incidental accumulation in the right frontoparietal area was found on salivary scintigraphy. Fluid-attenuated inversion recovery phase magnetic resonance (FLAIR phase MR) image showed diffuse high signal intensity in the same area. Anterior and posterior horns of the right lateral ventricle were obliterated and the midline was slightly shifted to the left side due to right frontoparietal swelling. On salivary scintigraphy, Tc-99m pertechnetate was incidentally accumulated in a subacute cerebral infarction lesion. Two years after the diagnosis of acute infarction, the second series of salivary scintigraphy showed no abnormal activity in the brain. FLAIR phase MR image also demonstrated markedly decreased high signal intensity in the previous infarction lesion without evidence of swelling indicating chronic cerebral infarction. CONCLUSION This case highlights that Tc-99m pertechnetate could accumulate in a subacute cerebral infarction lesion. The mechanism of an unexpected uptake of Tc-99m pertechnetate in unusual sites should be evaluated and kept in mind for better interpretation.

Basilar Artery Dissection in Myotonic Dystrophy Type 1

Abstract: Dear Editor, Myotonic dystrophy type 1 (DM1) is caused by a genetic malfunction involving the overexpression of the CTG sequence in DMPK. This affects the skeletal, cardiac, and smooth muscles, presenting with abnormalities in several body areas. In particular, cardiac fibrosis caused by invasion into cardiac muscle is associated with a high incidence of atrial fibrillation in patients with DM1.1 Atrial fibrillation has been reported as a major causal factor of stroke in DM1.2 Although previous studies have shown that DM1 is associated with an abnormality of the vascular smooth muscle,3 there has been no report of DM1 being related to a compromise of the macrovascular system, which includes arterial dissection. Dissection of the basilar artery (BA) is a very rare disease with an annual incidence of 1/400,000. We report the case of a patient with DM1 who was diagnosed with an acute cerebral infarction due to BA dissection without trauma. Artery dissection could be another etiology of ischemic stroke in patients with myotonic dystrophy. A 58-year-old female visited our clinic due to a gait disturbance, which had worsened 7 days before her visit. She was diagnosed with myotonic dystrophy in her 20s. Her older sister had also been diagnosed with DM1 in her 20s. A neurological examination revealed sensory deficits following light touches in the left facial region and the upper and lower extremities. Moreover, a cerebellar function test revealed left-limb dysmetria and a left-sided falling tendency during gait (National Institutes of Health Stroke Scale score of 5 and modified Rankin Scale score of 3). Percussion myotonia was observed in the abductor pollicis brevis. The findings of routine laboratory tests including of thyroid function were normal. PCRSouthern analysis with a biotin-(CTG) 10 probe revealed that DMPK (CTG) was amplified with over 550 repeats. The characteristic myotonic discharge was observed in the overall muscles. Electrocardiography revealed atrial fibrillation, but no conduction defect or tachycardia was present. Acute infarction of the right pons was confirmed in brain diffusion-weighted magnetic resonance angiography (MRA) (Fig. 1A). Dissection was suspected in the middle portion of the BA (Fig. 1B, C). Transfemoral cerebral angiography was performed to confirm dissection, which revealed flame-like tapering with long-segment stenosis at the same site (Fig. 1D). She was administered 5 mg of apixaban twice daily and 40 mg of atorvastatin once daily, and was discharged after her limb ataxia and gait disturbance improved. DM1 continuously weakens and depletes the muscles in the face, neck, and extremities, and it is characterized by myotonia when the invaded muscle is percussed.4 The severity of DM1 may vary in an individual patient. The adult-onset type is the most common, and its symptoms become distinct from the age of 40 years. DM1 is caused by mutations in DMPK located on chromosome 19q13.3. DM1 presents with abnormalities in several areas of the body, including the musculoskeletal, nervous, circulatory, and endocrine systems, and the gastrointestinal (GI) tract. DM1 presents with mainly musculoskeletal clinical symptoms. However, it also often presents with symptoms associated with the smooth muscle, including vomiting, constipation, diarrhea, and dysphagia resulting from the invasion of the smooth muscle of the GI tract, which can inChan-Hyuk Lee* Seung-Ho Jeon* Byoung-Soo Shin Hyun Goo Kang

Recurrent Cerebral Artery Dissection Associated with Seronegative Antiphospholipid Antibody Syndrome

Abstract: Stroke in young patients requires thorough evaluation as they often lack risk factors. Antiphospholipid syndrome can cause arterial thrombosis and pregnancy loss; hence, differential diagnoses should include seronegative antiphospholipid syndrome. We report a case of recurrent ischemic stroke caused by recurrent dissection in a patient with a history of pregnancy loss. A 33-year-old woman was admitted with global aphasia and right hemiparesis. During intra-arterial thrombectomy, a left middle cerebral artery dissection was detected. After 5.5 years, she was re-admitted for dysarthria, left facial palsy, subtle left hemiparesis, and right middle cerebral artery dissection. She tested negative for autoimmune diseases and vasculitis. However, underlying pathologic conditions could not be excluded because of the unique disease course. Finally, she was diagnosed with seronegative antiphospholipid syndrome. The concept of seronegative antiphospholipid syndrome has been proposed for patients with clinical features suggestive of antiphospholipid syndrome but with negative titers. However, this syndrome can only be diagnosed by exclusion. Furthermore, arterial dissection should be considered to be its main pathology. Antiphospholipid syndrome itself can be a risk factor for arterial dissection because it weakens the vessel walls. Therefore, diagnosis is important to prevent future complications in young patients with recurrent cerebral artery dissection, especially those associated with pregnancy-related morbidities.

Occlusion type and posterior communicating artery patency may predict favorable outcome after endovascular thrombectomy in selective basilar top occlusion

Abstract: Introduction The top of the basilar artery is a five-branched junction, consisting of two superior cerebellar arteries (SCAs), two posterior cerebellar arteries (PCAs), and the basilar artery itself. This study aimed to investigate prognostic factors in patients with selective acute basilar top occlusion managed with mechanical thrombectomy, focusing on occlusion type and posterior communicating artery (PCoA) patency. Methods Eligible patients who underwent endovascular treatment (EVT) for acute basilar top occlusion were reviewed. Patterns of basilar top occlusion were categorized as types I–III according to whether the SCA and PCA were visible on angiography. The PCoA was categorized as hypoplastic or non-visible (type I), normal patency but non-visible PCA through PCoA flow (type II), and fetal type (type III). Results Good outcomes were observed in 50% (21/42) and mortality in 11.9% (5/42) of the cases at 90 days. Patients with good outcomes showed lower baseline National Institutes of Health Stroke Scale (NIHSS) score (P = 0.001) and a higher proportion of type III basilar top occlusion (P = 0.004) and type III PCoA (P = 0.001). Multivariable logistic analysis showed that baseline NIHSS score [odds ratio (OR), 0.84; 95% confidence interval (CI), 0.73–0.97; P = 0.017) and type III PCoA (OR, 21.54, 95% CI, 1.33–347.97; P = 0.031) were independent predictors of good functional outcomes. Conclusion A low initial NIHSS score and good PCoA patency were independent predictors of favorable clinical outcomes after EVT in patients with acute basilar top occlusion. Furthermore, the favorable outcome group showed a high proportion of type III basilar top occlusions.