Re-evaluation of Repetitive Nerve Stimulation Test in Myasthenia Gravis and Myasthenic Syndrome

BACKGROUND: The repetitive nerve stimulation (RNS) test is a useful tool in the evaluation of neuromuscular transmission disorders. In our laboratory, we frequently use Oh's method, which tests 5 kinds of muscles (flexor carpi ulnaris (FCU), abductor digiti quinti (ADQ), orbicularis oculi, nasalis and trapezius) with 3 kinds of low rate stimulation (LRS) and high rate stimulation (HRS). This method has the advantage of high sensitivity, but is time consuming and painful to patients. So, we tried to reestablish the stage of RNS to overcome this problem and to create a useful test. METHODS: We analyzed RNS data from 369 patients, retrospectively. The number of patients with myasthenia gravis (MG) was 357 and the number with myasthenic syndrome was 12. We compared the sensitivity of individual muscle as well as individual stimulation rate. And we analyzed the results of MG and myasthenic syndrome to verify the usefulness of HRS. RESULTS: The sensitivity of RNS (LRS) was 69.7% in MG (generalized symptom 86.4%, only ocular symptom 40.3%). The sensitivity was higher with 3 pps and 5 pps than with 2 pps, while the exclusion of 2 pps did not affect the sensitivity. We found only 3 cases (1.0%) with post-tetanic exhaustion (PTE) in MG patients with negative results on LRS. The distributions of resting CMAP and post-exercise CMAP were different between MG and myasthenic syndrome. In most cases of myasthenic syndrome, the resting CMAP of ADQ and FCU was below 4.0 mV and post-exercise CMAP of ADQ and FCU was above 50%. CONCLUSIONS: LRS may be done with only 3 and 5 pps, and HRS of the ulnar nerve was helpful only if there was a suspicion of myasthenic syndrome (resting CMAP50%, in ADQ & FCU) or a borderline decremental response in LRS.

Presentation Time to Hospital and Recognition of Stroke in Patients with Ischemic Stroke

BACKGROUND: Recent advances in stroke therapies require patients to be treated very early after the onset of symptoms. To reduce the delay in time upon stroke and arriving at the hospital, we assessed the time delay, stroke recognition, and awareness before and after a public education program designed to increase recognition and awareness. METHODS: Prospective standardized and structured interviews were performed in 155 patients with ischemic stroke who were admitted to the Severance hospital before and after the public education program. The educational program included local newspaper articles, distribution of pamphlets, and lectures to 119 emergency care teams. Time delay, variable factors, stroke recognition, and stroke awareness of patients were then assessed (75 pre-education and 80 post-education groups). RESULTS: 52% of the pre-education group and 52.5% of the post-education group arrived at the hospital within 24 hours. Those who arrived within 3 hours were only 21.3% and 15% respectively. A direct visit to the hospital and a cardioembolic infarction appeared to be associated with a shorter time delay. About half of the patients recognized their symptoms as a stroke before a diagnosis was made by a doctor. Most of them had known that a stroke should be treated urgently. However, the stroke recognition and awareness was not associated with an early arrival, which suggests that their knowledge was not solid. The efforts to inform the public using local newspaper articles and pamphlets geared towards the local residents for the limited time period was not effective in shortening arrival times. CONCLUSIONS: Many of the stroke patients did not arrive within the therapeutic time window. Our findings suggest that extensive and multi-directional campaigns should be performed to reduce the time delay. Our findings also suggest that educational aims should include the need for the rapid treatment of stroke and a therapeutic time window as well as stroke recognition.

Muscle fiber type disproportion with an autosomal dominant inheritance

Congenital muscle fiber type disproportion (CFTD) has been described as a form of congenital myopathy characterized by the smallness and marked predominance of type 1 fibers in a muscle biopsy. Clinical manifestations include hypotonia, nonprogressive muscle weakness, joint contractures, and skeletal deformities. However, it has also been noted that the same pathologic alterations appeared in clinically diverse conditions. Recently, we experienced a family, a mother and two children, in which a muscle biopsy showed the mother to have muscle fiber type disproportion. This case was unusual in that there was a significant progression of weakness, an absence of neonatal hypotonia, and other commonly associated musculo-skeletal deformities. In this report, we describe the clinicopathologic features of the family with a brief review about muscle fiber type disproportion.

Delayed-onset Movement Disorders after Carbon Monoxide Intoxication

BACKGROUND: Presently, it is well known that there are neurological and systemic complications after carbon monox-ide (CO) intoxication. Until recently, delayed-onset movement disorders after CO intoxication were rarely reported. We analyzed 32 patients with delayed onset movement disorders after CO intoxication. METHODS: We reviewed the medical records of 242 patients admitted to the Yonsei University Medical Center from January 1986 to December 1996 due to CO intoxication. Patients were analyzed with respect to movement disorders, onset, latency, and radiological findings. RESULTS: Among the 242 patients of CO intoxication, 32 (13.2%) patients had delayed-onset movement disorders. Of these, 23 (71.9%) had parkinsonism, 5 (15.6%) had dystonia, 3 (9.4%) had chorea, and 1 (3.1%) had myoclonus. The mean age of the patients was 46.66 +/-16.91 years. Among the 4 patients with CO intoxication occuring at age 17 or younger (Childhood group), 2 had parkinsonism and 2 had focal dystonia. The mean age of the Childhood group was 1 7 . 7 5 +/-6.99 years. Among the 28 patients with CO intoxication occuring at age 18 or older (Adult group), 21 (75%) had parkinsonism, 3(10.7%) dystonia, 3(10.7%) chorea, and 1(3.6%) myoclonus. Among the 3 patients with dystonia in the Adult group, 1 had focal dystonia and 2 had segmental dystonia. The mean age of the adult group was 50.79 +/-1 3 . 4 6 years. The mean latency between CO intoxication and the onset of movement disorders was 27.20 +/-27.94 weeks in the Childhood group and 9.60 +/-14.97 weeks in the Adult group. The mean latency between CO intoxication and the onset of movement disorders was 6.44 +/-6.76 weeks in parkinsonism, 41.76 +/-27.99 weeks in dystonia, 4.0 weeks in chorea, and 8.0 weeks in myoclonus. The mean latency in dystonia was longer than in the others. Among the 23 patients who underwent brain computed tomography, 12 (52.2%) had abnormal findings. Low density lesions were found in the globus pallidus (13.0%), cerebral white matter (13.0%), and both globus pallidus and cerebral white matter (17.4%). One (14.3%) patient showed cortical atrophy while another patient showed both cortical atrophy and low density in cerebral white matter. CONCLUSIONS: The development of a delayed-onset movement disorder after CO intoxication is not rare. In our research, the radiological findings of patients with delayed-onset movement disorders after CO intoxication were inconsistant. The findings revealed no correlations with the various types of delayed-onset movement disorders.

Clinical characteristics of meningitis in adults

The meningitis occur within a closed anatomic space, so they have many similar clinical features and characteristic CSF abnormalities. But the temporal profile of many meningitis is distinctive from aseptic meningitis with spontaneous remission to bacterial or tuberculous meningitis with fatal outcome without treatment. Therefore early accurate differential diagnosis is required. The development of diagnostic tools and treatment, and increase of immunodeficient state and resistant pathogens have changed the distribution of main pathogens of meningitis from the past. Therefore we analyzed 241 medical records with final diagnosis as 'infectious meningitis' to evaluate the distribution of pathogens in Korea and any differential points of clinical, laboratory, and radiologic, profile according to etiology. 1. The etiologic distributions were followings, Aseptic meningitis in 100 patient(41.5%), tuberculous meningitis in 58 patients(24.1%), bacterial meningitis in 48 patients(19.9%), and fungal in 16 patients(6.6%). 2. The intense seasonal occurrence was noted in aseptic meningitis with summer. 3. Fever and headache were noted in almost all patients Altered mental status were noted in 39.6% of bacterial meningitis, 53.41% of tuberculous meningitis but not in fungal and aseptic meningitis. Meningeal irritation signs were noted in less patients(25%) with fungal meningitis but in more with aseptic, bacterial or tuberculous meningitis m 52-66.7%. Most of all focal neurologic signs were present in bacterial or tuberculous meningitis. 4. Many immunocompromized patients had fungal meningitis, three of which showed normal CSF leukocyte counts And it pointed up the importance of intensive etiologic evaluation in immunodeficient patients with clinically suspected symptoms of meningitis. 5. CSF findings at admission were following. CSF leukocytes were mean 206-258/yL in aseptic, tuberculous or fungal meningitis. But in bacterial meningitis leukocyte counts were greater than 1,000/mL in mom than half of patients. The differential counts of leukocytes were monocyte predominant except in bacterial meningitis. The reductions of CSF sugar were noted in bacterial, tuberculous, or fungal meningitis. Characteristically all patients with extremely low CSF sugar(less than 10mg/dL) had bacterial meningitis. 6. The most frequent pathologic findings in neuroimaging study were hydrocephalus(20patients: 9.1%) and meningeal enhancement(19patient,: 8.6%). Small enhancing mass(8patients: 3.6%.) and focal infarction(8patients: 3.6%) were noted less frequently. These abnormal radiologic findings were noted in 2 patients(2.0%) with aseptic meningitis, 15 patients(38.7%) with bacterial meningitis, 29 patients(50.0%) with tuberculous meningitis and 5 patients(35.7%) with fungal meningitis.

Delayed-onset movement disorders after static brain lesions

We studied 55 patients with static brain lesions who developed delayed-onset movement disorders. Of these, 29(52.7%) had pakinsonism, 17(30.9%) dystonia, 6(10.9%) chorea, 2(3.6%) tremor, and I(I.8%) myoclonus. The precipitating insults included carbon mono-oxide, poisoning in 32(58.2%), 6(10.9%), encephalitis in 5(9.1%)head injury, stoke and hypoxia, in 6(10.9%) patients each. Among the four Patients with initial insult occurring at age 2years or younger(infant group), all had dystonia. Distribution of dystonia was focal in one(25%), segmental in two(50%), and unilateral in one patient(25%). The mean latency between the original injury and the onset of movement disorder was 378.03+277.13 weeks. Among the 11 patient initial insults occurring between ages 5 and 17(childhood group), 7 had dystonia, 3 parkinsonism, 1chorea. The distribution of dystonia was focal in one, segmental in five, and unilateral in one patient; the mean latency between the original injury and the onset of movement disorder was 91.3+,230.1 weeks. Among the 40patients with initial insults occurring at ages 23 or older (adult group), 26(65.0%) had parkinsonism, 6(15.0%) dystonia, 5(12.5%) chorea, 2(5.0%) tremor, 1(2.5%) myoclonus. The distribution of dystonia in patient was focal in two(33.0%), and segmental in four(67.7%) patients. The mean latency of movement disorder onset in the 40 patients, of the adult group was 17.25+43.67weeks. Brain injury at a young age was associated with a longer latency to onset of subsequent movement disorder. Among the 45 initial brain computed tomography, 28 (62.2%) had abnormal findings; 14(31.1%) low density lesion in the basal ganglia, 7(15.6%) low density lesions in the cerebral white matter, 2(4.4%) low density lesion in the cerebral white matter and basal ganglia, and 5(l1.1%) cortical atrophy. Seventeen (37.8%) had normal neuroimaging finding. Many, but not all, patients had lesionon on brain imaging, but there was no clear correlation between the sites of damage on imaging and the clinical manifestation.

Aseptic Meningitis Associated with OKT3 Therapy

Aseptic meningitis may rarely occur with the use of OKT3 murin monoclonal antibody, which is an immunosuppressive agent for the prevention and treatment of acute rejection in solid transplantation. We present a patient with aseptic meningitis, developed during OKT3 therapy, who shows characteristic clinical features and CSF findings consistent with OKT3 associated aseptic meningitis.