Sural-sparing pattern: A study against electrodiagnostic subtypes of Guillain-Barre syndrome.

Objective: To study sural-sparing pattern in Guillain-Barre syndrome (GBS) and compare it among GBS's electrodiagnostic subtypes, classified by two recent criteria. Methods: This study retrospectively reviewed clinical data and electrodiagnostic studies (EDXs) of 88 GBS patients diagnosed in a tertiary care hospital (2010-2019). Results: Overall, 79/88 (89.8%) and 36/45 (80%) patients had bilateral sensory nerve conduction studies (NCS) in the first EDX and follow-up EDX, respectively. Sural-sparing occurred in all subtypes (50% overall occurrence rate), most commonly in demyelination. There was no statistically significant difference in sural-sparing occurrence rates between demyelinating and axonal GBS; however, sural-sparing in axonal GBS tended to show a lower number of abnormal upper-limb sensory nerve action potentials (SNAPs) than demyelinating GBS. Shifting between sural-sparing and no sural-sparing occurred in approximately-one-fourth of patients receiving serial studies. Follow-up EDX additionally discovered 20% of all sural-sparing. Unilateral EDX could have omitted up to 30% of sural-sparing. Conclusions: Sural-sparing is less obviously manifested in axonal than demyelinating GBS, with respect to the number of affected upper-limb SNAPs. Extended sensory NCS is worth in detecting sural-sparing as a supportive electrodiagnostic GBS feature. Significance: This report showed one different character of sural-sparing (number of affected upper-limb SNAPs) between demyelinating and axonal GBS.

Ala97Ser transthyretin amyloidosis-associated polyneuropathy, clinical and neurophysiological profiles in a Thai cohort.

BACKGROUND: Ala97Ser transthyretin amyloidosis-associated polyneuropathy (ATTRA97S-PN) is a rare form of inherited polyneuropathy, usually manifesting with late-onset (> 50) progressive polyneuropathy. This mutation is mostly prevalent in Taiwanese and Han-Chinese individuals. The aim of this study was to describe the clinical and comprehensive neurophysiological profiles of ATTRA97S-PN in Thai patients. METHODS: The clinical profiles and serial neurophysiologic studies (nerve conduction study (NCS), quantitative sensory test (QST), and comprehensive autonomic function test (AFT)) of symptomatic ATTRA97S-PN patients who had been followed-up at King Chulalongkorn Memorial Hospital during 2010-2020 were retrospectively reviewed. RESULTS: Nine symptomatic patients (55.6 % were male) from four unrelated families were included. All were Thais of mixed Thai Chinese descent. The mean age of onset was 48.3 (32-60) years. The mean age at diagnosis was 54.8 (33-66) years. Three patients developed early-onset (< 40y) polyneuropathy. The mean Neuropathy Impairment Score was 41.33 (10-92) at diagnosis. Sensory (9/9) and autonomic (9/9) neuropathies were more frequent than motor neuropathy (5/9), which appeared in the late stage of disease. Hypoesthesia in the feet, and gastrointestinal autonomic symptoms were frequently reported as the initial symptoms. The course of neuropathy progressed over years to decades. The worsening of neuropathy tended to progress faster once motor nerves were affected in both clinical and neurophysiological aspects. Concurrent cardiac amyloidosis was found in 6/9 patients. NCS showed length-dependent sensorimotor axonal polyneuropathy in 5/9 patients, and median neuropathy at the wrist (mostly bilateral) in 7/9 patients. QST showed abnormalities in the vibratory detection threshold, the cold detection threshold and the heat pain sensation in 8/9, 8/9 and 7/7 tested patients, respectively. AFT results were abnormal in all. The mean composite autonomic severity score was 5 (3-9). CONCLUSIONS: This clinical study is the first of ATTRA97S-PN in Thai patients. The mixed polyneuropathy-cardiopathy phenotype was the most common manifestation. In this cohort, the age of onset was lower, and the course of neuropathy was relatively longer, than that in previous studies. Some patients may develop early-onset polyneuropathy. This mutation has not yet been documented in any population other than Han Chinese-related populations, probably suggesting a founder effect. Further studies are warranted.

Founder effect of the TTTCA repeat insertions in SAMD12 causing BAFME1.

Benign adult familial myoclonic epilepsy type 1 (BAFME1) in several Japanese and Chinese families has recently been found to be caused by pentanucleotide repeat expansions in SAMD12. We identified a Thai family with six members affected with BAFME. Microsatellite studies suggested a linkage to the BAFME1 region on chromosome 8q24. Subsequently, long-read whole-genome sequencing showed the (TTTTA)446(TTTCA)149 in intron 4 of SAMD12 in an affected member. Repeat-primed PCR and long-range PCR revealed that the pentanucleotide repeat expansions segregated with the disease status. Our Thai family is the first non-Japanese and non-Chinese family with BAFME1. SNP array showed that the aberrant repeats had the same haplotype as those previously determined in Japanese and Chinese patients suggesting a common ancestry. The variant is estimated to arise ~12,000 years ago.

Mid-palm recording technique, a new electrodiagnostic approach in Martin-Gruber anastomosis.

INTRODUCTION: Median and ulnar motor nerve conduction study recording from median-innervated 2nd lumbrical and ulnar-innervated 1st palmar and 2nd dorsal interossei is designated in electrodiagnostic evaluation of carpal tunnel syndrome. In this technique, both responses are recorded by the same surface recording electrode placing over their shared motor point in mid-palm. To the best of our knowledge, this technique has never been utilized in demonstration of Martin-Gruber anastomosis. CASE REPORTS: By applying this technique to the conventional CMAP comparison method, the authors accordingly demonstrated Martin-Gruber anastomosis in four cases. Three presented with focal mononeuropathies of the upper limbs, including a severe carpal tunnel syndrome, a mild to moderate carpal tunnel syndrome, and an ulnar neuropathy. One was a normal individual. SIGNIFICANCE: This report described a new electrophysiological pattern of MGA. Adding the mid-palm recording to conventional CMAP comparison method provides a broader view in terms of innervation of MGA. This technique is not complicated and can be added to the electrophysiological investigation for complete studying of the innervated muscles in MGA.

Needle EMG, a Jigsaw to Disclose Lipid Storage Myopathy Due to Multiple Acyl-CoA Dehydrogenase Deficiency.

Multiple acyl-CoA dehydrogenase deficiency is a rare autosomal recessive inborn error of metabolism. The late-onset multiple acyl-CoA dehydrogenase deficiency is frequently caused by mutations in ETFDH gene. Because of its clinical heterogeneity, diagnosis and treatment of late-onset multiple acyl-CoA dehydrogenase deficiency are often delayed. The authors described a previously healthy 40-yr-old Thai woman presenting with subacute severe weakness of bulbar-limb muscles and elevated serum creatine kinase. The authors emphasized the importance of needle EMG and prompt muscle histopathological evaluation, which rapidly led to the diagnosis and riboflavin therapy, resulting in a dramatic and rapid improvement before genetic study disclosed mutation in ETFDH gene.

Isolated intermittent neurogenic priapism: an unusual presentation in degenerative lumbar spinal stenosis.

Priapism is a relatively uncommon clinical presentation. The well-recognised causes are sickle cell anaemia and the use of medications, such as vasoactive erectile agents. Infrequently, it could be the result of lumbar spinal stenosis. The authors reported an elderly man with 1-year history of isolated intermittent priapism aggravated by walking. MRI showed lumbosacral spondylosis with severe stenosis at the level of L4-L5. Total laminectomy of L4 and L5 was done, resulting in a rapid and complete resolution of symptom without recurrence during the follow-up time of 10 years.

Fulminant respiratory muscle paralysis, an expanding clinical spectrum of mitochondrial A3243G tRNALeu mutation.

Mitochondrial disease is a group of rare disorders, caused by mitochondrial dysfunction. They are usually the result of mutations of either mitochondrial DNA or nuclear DNA. A3243G transition in the tRNALeu is one the most frequent mutations of the mitochondrial DNA. Phenotypic expression of this mutation varies. The most well-recognized phenotype is Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome. Isolated myopathy with respiratory muscle weakness in this mutation has been rarely documented. The authors reported a 20-year-old Asian female presenting with a fulminant hypoventilatory respiratory failure with mild weakness of the limbs. Electrophysiologic study showed evidences of myopathy. Restrictive physiology of the lungs was demonstrated by pulmonary function test. Subsarcolemmal accumulation of mitochondria was demonstrated by Gomori trichrome and succinate dehydrogenase stains. Genetic study revealed the A3243G mutation in mitochondrial DNA in peripheral blood Isolated mitochondrial myopathy severely affecting respiratory muscles may be considered as an uncommon clinical spectrum of A3243G mitochondrial disease.

A newly identified locus for benign adult familial myoclonic epilepsy on chromosome 3q26.32-3q28.

Benign Adult Familial Myoclonic Epilepsy (BAFME) is an autosomal dominant disorder characterized by adult-onset cortical tremor or action myoclonus predominantly in the upper limbs, and generalized seizures. We investigated a Thai BAFME family. Clinical and electrophysiological studies revealed that 13 were affected with BAFME. There were a total of 24 individuals studied. Genetic analysis by genome-wide linkage study (GWLS) was performed using 400 microsatellite markers and excluded linkage of the previous BAFME loci, 8q23.3-q24.1, and 2p11.1-q12.2. GWLS showed that the disease-associated region in our Thai family was linked to a newly identified locus on chromosome 3q26.32-3q28. This locus represents the fourth chromosomal region for BAFME.

Clinical manifestations of acetylcholine receptor antibody positive and negative myasthenia gravis.

BACKGROUND: Acquired myasthenia gravis (MG) is the most common neuromuscular junction disorder. Acetylcholine receptor (AChR) antibody is found in the majority of MG. OBJECTIVE: Describe and compare the clinical manifestations of MG patients with and without the presence of serum AChR antibody. MATERIAL AND METHOD: Between 2009 and 2010, 90 cases with MG, treated at the adult neurology service of King Chulalongkorn Memorial Hospital were consecutively recruited. Serum AChR antibody was measured by enzyme linked immunosorbent assay. Result of 0.45 nmole per liter or over is considered positive. Patients were divided into two groups based on serological status. Demographic data and clinical parameters were recorded and compared. RESULTS: Mean age was 47.5 +/- 15.6 years. Sixty-eight (75.5%) were female. Twenty-two (24.4%) had ocular MG and sixty-eight (75.6%) had generalized MG. Mean age of onset was 40.9 +/- 15.2 years. Sixty-seven (74.4%) were AChR antibody positive and twenty-three (25.6%) were AChR antibody negative. Limb/ocular-limb weakness was more commonly found in AChR antibody positive (p = 0.12) while pure ocular weakness was significantly found in AChR antibody negative (p = 0.006*). Myasthenic crisis (MC) tended to develop in AChR antibody positive (p = 0.06). Numbers of patients with moderate to severe weakness were significantly higher in AChR antibody positive (p = 0.04*). Thymic pathology was found in 72.3% of thymectomized AChR antibody positive patients. None of thymectomized seronegative patients had abnormal thymus. Good response to acetylcholine esterase inhibitors was more frequent in AChR antibody positive patients (p = 0.009*). Immunotherapy and thymectomy (p = 0.001*) were more frequently provided in AChR antibody positive patients. CONCLUSION: AChR antibody positive MG manifested more severe, generalized weakness with frequent MC. Abnormal thymic histopathology was more frequently found in AChR antibody positive MG. Response to ACEI was better in AChR antibody positive group. However overall outcomes of both groups were favorable without any difference.

Statin-associated myasthenic weakness.

BACKGROUND: Statin-associated myasthenic weakness is uncommonly recognized. Since 2002, there have been 14 cases described in literatures. However, the underlying mechanism is still unknown. CASE REPORT: In 2007, a 50-year-old woman with generalized, limb predominated, myasthenia gravis (MG), whose MG status has been "minimal manifestation" for several years, developed moderately severe fluctuating bulbar weakness a few weeks after starting simvastatin 20 mg/day. Simvastatin was discontinued and dosage of cholinesterase inhibitor was temporarily increased. The symptoms resolved and she was back to her previous status in one month. In 2008, two weeks after re-challenge with simvastatin 10 mg/day, bulbar weakness re-occurred Antibody to acetylcholine receptors was measured 4.25 nmole/L. Serum creatine phosphokinase was normal. Electrophysiologic tests showed evidences of postsynaptic neuromuscular junction disorder without evidence of myopathy. The symptoms were again resolved after discontinuation of statin and temporarily increased dosage of cholinesterase inhibitor. She was back to previous status in two months. Hypercholesterolemia was then controlled with ezetimibe without any worsening in MG status. CONCLUSION: Because of the wide use of statins in clinical practice, physicians should be aware of this potential adverse effect. The incidence ofstatin-associated myasthenic weakness should be clearly investigated Challenge with other brands of statin or with reduced dosage is not beneficial in these patients. Non-pharmacological treatment and non-statin medication may be considered

Bilateral subdural hematomas and hearing disturbances caused by spontaneous intracranial hypotension.

Spontaneous Intracranial Hypotension (SIH) is an uncommon headache syndrome. Patients classically present with orthostatic headache, tinnitus, and diplopia. The authors reported a 43 year-old man who presented with orthostatic headache, tinnitus, and hearing impairment for 3 months. Physical examination was unremarkable except for auditory impairment. The audiogram revealed minimal low-frequency neurosensori hearing loss suggesting a cochlear lesion. Computed tomography of the brain revealed bilateral thin chronic subdural hematomas. He underwent burr-hole surgery. Headache and auditory symptoms persisted and reevaluation of this syndrome was performed MRI of the brain showed diffuse smooth enhanced dura mater low lying position of midbrain, pons, medullar and cerebellar tonsil, as well as enlarged pituitary gland compatible with low CSF pressure syndrome. MRI of the whole spine could not demonstrate the site of CSF leakage. The patient was much improved after conservative treatments with hydration and bed rest. One year after treatment, he had no headache and only mild tinnitus was reported.

Safety profile of multilevel chemical denervation procedures using phenol or botulinum toxin or both in a pediatric population.

OBJECTIVE: To investigate the safety of single and repeated multilevel injections of botulinum toxin (BoNT) alone or a combination of phenol and BoNT performed under general anesthesia in children with chronic muscle spasticity. DESIGN: Retrospective cohort study. Data from 336 children who received a total of 764 treatments were analyzed. Mean age was 7.4 yrs, and 90% had diagnoses of cerebral palsy. RESULTS: The overall complication rate was 6.8%, similar to rates reported in comparable studies of BoNT alone and combined BoNT and phenol. Of the total number of injection sessions with complications, 1.2% were anesthesia related and 6.3% were injection related; none resulted in any deaths or long-term morbidity. Injection-related complications were most frequently local symptoms of short duration. These were comparable with those reported previously, except that in this series there was a rare occurrence of dysesthesias (0.4%) with phenol injections. Complications occurred more frequently in patients injected with a combination of phenol and BoNT vs. BoNT alone, but no single causal factor can be implicated. No increase in complications with repeat injections was observed, and there was no correlation of complication rates with dosage of either agent. CONCLUSIONS: Although these procedures are not without adverse effects, this series suggests that the potential benefits outweigh the risks.

Marchiafava-Bignami disease: a case report.

Marchiafava-Bignami Disease (MBD) is a rare, severe and usually fatal neurological disorder associated with chronic alcoholism. Previously, the definite diagnosis was confirmed at the autopsy. After the era of modern imaging technology, diagnosis was based on clinical profiles, history of alcoholism and specific location of pathology in corpus the callosum demonstrated by MRI. The authors reported a case of MBD in a 41 year-old alcoholic Thai male who presented with acute confusion and ataxia. MRI of the brain demonstrated demyelination, edema and necrosis of the corpus callosum with extensive symmetrical subcortical white matter lesions. He had a dramatic recovery after treatment with intravenous thiamine. Follow-up MRI revealed atrophic and cystic changes of the corpus callosum and almost complete resolution of the subcortical lesions. Recently, 15 cases of MBD with specific corpus callosal lesion, demonstrated by MRI, were published in the English literature. All had a favorable outcome after treatment with thiamine. Only one case had extensive extracallosal lesions and this case also had a good recovery after treatment. Now, MBD is not a fatal disease and early diagnosis and treatment are crucial.