Comparative Outcomes of Respiratory Failure Associated with Common Neuromuscular Emergencies: Myasthenia Gravis versus Guillain-Barré Syndrome.

Background and objectives: Myasthenia gravis (MG) and Guillain-Barré Syndrome (GBS) are autoimmune neuromuscular disorders that may present as neuromuscular emergencies requiring mechanical ventilation and critical care. Comparative outcomes of these disease processes, once severe enough to require mechanical ventilation, are not known. In this study, we compared the patients requiring mechanical ventilation in terms of in-hospital complications, length of stay, disability, and mortality between these two disease entities at a national level. Materials and Methods: Mechanically ventilated patients with primary diagnosis of MG (n = 6684) and GBS (n = 5834) were identified through retrospective analysis of Nationwide Inpatient Sample (NIS) database for the years 2006 to 2014. Results: Even though mechanically ventilated MG patients were older (61.0 ± 19.1 versus 54.9 ± 20.1 years) and presented with more medical comorbidities, they had lower disease severity on admission, as well as lower in-hospital complications sepsis, pneumonia, and urinary tract infections as compared with GBS patients. In the multivariate analysis, after adjusting for confounders including treatment, GBS patients had significantly higher disability (odds ratio (OR) 15.6, 95% confidence interval (CI) 10.9-22.2) and a longer length of stay (OR 3.48, 95% CI 2.22-5.48). There was no significant difference in mortality between the groups (8.45% MG vs. 10.0% GBS, p = 0.16). Conclusion: Mechanically ventilated GBS patients have higher disease severity at admission along with more in-hospital complications, length of stay, and disability compared with MG patients. Potential explanations for these findings include delay in the diagnosis, poor response to immunotherapy particularly in patients with axonal GBS variant, or longer recovery time after nerve damage.

Are We Overlooking Stroke Chameleons? A Retrospective Study on the Delayed Recognition of Stroke Patients.

BACKGROUND AND PURPOSE: New effective recanalization therapies are currently available for acute ischemic stroke; yet a vast majority of stroke patients are left untreated. The lack of early recognition may be because often times, stroke patients present with atypical manifestations that resemble other conditions (which are referred to as "stroke chameleons"). We set to study the proportion of patients with delayed stroke recognition in a single center. METHODS: We performed a retrospective analysis of a prospectively collected data over a 9-year period. All adult patients discharged with the diagnosis of ischemic stroke or transient ischemic attack (TIA) were identified and traced for their diagnosis on admission. Those cases with a diagnosis other than ischemic stroke or TIA on admission were identified as possible stroke chameleons and categorized into different groups according to the occurrence of neurological or non-neurological manifestations at presentation. RESULTS: Of 2,303 cases with discharge diagnosis of ischemic stroke or TIA, 919 (39.9%) were found to be possible stroke chameleons. More than half of these patients (58.4%) presented with neurological manifestations including disorders of the somatic sensation (33%), alteration of consciousness (30%), and disorders of speech/language (11%). The remaining possible stroke chameleons had manifestations pertaining to other organ systems such as cardiopulmonary, gastrointestinal, systemic infection, trauma, and thromboembolic events elsewhere. CONCLUSIONS: In our cohort, a surprisingly large percentage of possible stroke chameleons was observed. It is important to confirm our findings, study the impact on clinical outcome, and develop strategies for early stroke patient recognition.

Black Tar Heroin Skin Popping as a Cause of Wound Botulism.

BACKGROUND: Botulism is a rare potentially fatal and treatable disorder caused by a bacteria-produced toxin that affects the presynaptic synaptic membrane resulting in a characteristic neuromuscular dysfunction. It is caused by either the ingestion of the toxin or the bacteria, inhalation, or wound infection. We present our observations with a descriptive case series of wound botulism secondary to black tar heroin (BTH) injection. METHODS: We report a retrospective single-center case series of 15 consecutive cases of wound botulism presenting to University Medical Center of El Paso. Medical records where reviewed to obtain demographic information, clinical presentation, treatment, and outcome. RESULTS: We identified fifteen patients with mean age of 47 years: twelve men, and three women. All had administered BTH through skin popping and had abscesses in the administration areas. By history, the most common symptoms were dysphagia (66%), proximal muscle weakness of upper and lower extremity (60%), neck flexor muscle weakness (33%), ophthalmoplegia (53%), bilateral ptosis (46%), dysarthria (53%), double vision (40%), blurred vision (33%), and dry mouth (20%). During the examination, the most common features noted were: proximal muscle weakness of upper and lower extremities (73%), ophthalmoplegia (53%), ptosis (46%). In patients with documented wound botulism, the pupils were reactive in 46%. All patients required mechanical ventilation and were treated with the trivalent antitoxin. Eleven patients (73.3%) were discharged home, two were transferred to a skill nursing facility, and two were transferred to long-term acute care facility. CONCLUSION: In our patients, BTH injection, involving the action of injecting under the skin acetylated morphine derivatives (mostly 6-monoacetylmorphine and 3-monoacetylmorphine), was associated with the development of botulism. The availability of BTH at the US-Mexican border is not surprising since it is frequently produced in Latin America. Its association with the development of botulism should be recognized early to allow a prompt diagnosis and treatment with the antitoxin. A clinical feature worth noting is the presence of normal pupillary light reflex in nearly half of patients. Therefore, the presence of a normal pupillary response does not exclude the presence of wound botulism.

Defective fast inactivation recovery of Nav 1.4 in congenital myasthenic syndrome.

OBJECTIVE: To describe the unique phenotype and genetic findings in a 57-year-old female with a rare form of congenital myasthenic syndrome (CMS) associated with longstanding muscle fatigability, and to investigate the underlying pathophysiology. METHODS: We used whole-cell voltage clamping to compare the biophysical parameters of wild-type and Arg1457His-mutant Nav 1.4. RESULTS: Clinical and neurophysiological evaluation revealed features consistent with CMS. Sequencing of candidate genes indicated no abnormalities. However, analysis of SCN4A, the gene encoding the skeletal muscle sodium channel Nav 1.4, revealed a homozygous mutation predicting an arginine-to-histidine substitution at position 1457 (Arg1457His), which maps to the channel's voltage sensor, specifically D4/S4. Whole-cell patch clamp studies revealed that the mutant required longer hyperpolarization to recover from fast inactivation, which produced a profound use-dependent current attenuation not seen in the wild type. The mutant channel also had a marked hyperpolarizing shift in its voltage dependence of inactivation as well as slowed inactivation kinetics. INTERPRETATION: We conclude that Arg1457His compromises muscle fiber excitability. The mutant fast-inactivates with significantly less depolarization, and it recovers only after extended hyperpolarization. The resulting enhancement in its use dependence reduces channel availability, which explains the patient's muscle fatigability. Arg1457His offers molecular insight into a rare form of CMS precipitated by sodium channel inactivation defects. Given this channel's involvement in other muscle disorders such as paramyotonia congenita and hyperkalemic periodic paralysis, our study exemplifies how variations within the same gene can give rise to multiple distinct dysfunctions and phenotypes, revealing residues important in basic channel function.

Spinal muscular atrophy: diagnosis and management in a new therapeutic era.

Spinal muscular atrophy (SMA) describes a group of disorders associated with spinal motor neuron loss. In this review we provide an update regarding the most common form of SMA, proximal or 5q-SMA, and discuss the contemporary approach to diagnosis and treatment. Electromyography and muscle biopsy features of denervation were once the basis for diagnosis, but molecular testing for homozygous deletion or mutation of the SMN1 gene allows efficient and specific diagnosis. In combination with loss of SMN1, patients retain variable numbers of copies of a second similar gene, SMN2, which produces reduced levels of the survival motor neuron (SMN) protein that are insufficient for normal motor neuron function. Despite the fact that understanding of how ubiquitous reduction of SMN protein leads to motor neuron loss remains incomplete, several promising therapeutics are now being tested in early-phase clinical trials.

Dysphagia as the Presenting Symptom for Inclusion Body Myositis.

Dysphagia can be one of the manifestations of inflammatory myopathies (IMs). In some patients, it can be one of the presenting symptoms or the only symptom. We present a patient with dysphagia and progressive muscle weakness who was eventually diagnosed with inclusion body myositis (IBM). Treatment with oral steroid provided no major improvement in symptoms and thus was eventually stopped. Dysphagia in IMs is associated with complications and poor prognosis. A multidisciplinary approach is needed in its diagnosis and management as this report exemplifies.

Racial/ethnic disparities in hospital utilization in intracerebral hemorrhage.

BACKGROUND AND PURPOSE: There is evidence that racial and ethnic differences among intracerebral hemorrhage (ICH) patients exist. We sought to establish the occurrence of disparities in hospital utilization in the United States. METHODS: We identified ICH patients from United States Nationwide Inpatient Sample database for years 2006-2014 using codes (DX1 = 431, 432.0) from the International Classification of Diseases, 9th edition. We compared five race/ethnic categories: White, Black, Hispanic, Asian or Pacific Islander, and Others ( Native American and other) with regard to demographics, comorbidities, disease severity, in-hospital complications, in-hospital procedures, length of stay (LOS), total hospital charges, in-hospital mortality, palliative care, (PC) and do not resuscitate (DNR). We categorized procedures as lifesaving (i.e. ventriculostomy, craniotomy, craniectomy, and ventriculoperitoneal (VP) shunt), life sustaining (i.e. mechanical ventilation, tracheostomy, transfusions, and gastrostomy). White race/ethnicity was set as the reference group. RESULTS: Out of 710,293 hospitalized patients with ICH 470,539 (66.2%), 114,821 (16.2%), 66,451 (9.3%), 30,297 (4.3%) and 28,185 (3.9%) were White, Black, Hispanic, Asian or Pacific Islander, and Others, respectively. Minorities (Black, Hispanic, Asian or Pacific Islander, and Others) had a higher rate of in-hospital complications, in-hospital procedures, mean LOS, and hospital charges compared to Whites. In contrast, Whites had a higher rate of in-hospital mortality, PC, and DNR. In multivariable analysis, all minorities had higher rate of MV, tracheostomy, transfusions, and gastrostomy compared to Whites, while Hispanics had higher rate of craniectomy and VP shunt; and Asian or Pacific Islander and Others had higher rate of craniectomy. Whites had a higher rate of in-hospital mortality, palliative care, and DNR compared to minorities. In mediation analysis, in-hospital mortality for whites remained high after adjusting with PC and DNR. CONCLUSION: Minorities had greater utilization of lifesaving and life sustaining procedures, and longer LOS. Whites had greater utilization of palliative care, hospice, and higher in-hospital mortality. These results may reflect differences in culture or access to care and deserve further study.

Is black tar heroin use associated with wound botulism? A report of two Hispanic patients.

Wound botulism is a potentially lethal condition that can cause paralysis. Its association with black tar heroin is a well-established fact. It is essential to alert clinicians in recognizing the patients with history of injection drug abuse presenting with clinical features of botulism early on admission for prompt diagnosis and treatment.

Case Report: 84 year-old woman with alien hand syndrome.

Background: Alien hand syndrome [AHS] is a rare and ill-defined neurological disorder. It produces complex, goal-directed motion of one hand that is involuntarily instigated. This syndrome characteristically arises after brain trauma, brain surgery, stroke or encephalitis. We describe a case of AHS in a patient who had a previous episode of subarachnoid hemorrhage affecting the left frontal lobe and corpus callosum. Case presentation: An 84-year-old woman presented to the emergency department complaining of headaches and several episodes of her left arm moving as if it was groping around trying to grab at her own body. A computed tomography scan of the head demonstrated an acute left superior frontal hemorrhage with compression of the corpus callosum. Transcranial Doppler report showed no significant abnormality in the insonated vessels. After being stabilized for the acute bleed, she was treated with clonazepam 0.5 mgat night for the uncontrolled hand movements. Her movements resolved by her next month follow up. The diagnosis of AHS was made based on her clinical presentation, characterization of the movement and localization correlating with findings in neuroimaging. Conclusion: We document a rare neurologic disorder seen in patients presenting with a history of previous strokes and a typical description of involuntary and unintentional, uncontrolled unilateral arm movements with repetitive grasping. The present case has a combination of frontal and callosal lesions.  These findings appear to support a potential destruction leading to the rare syndrome.