Neurological Respiratory Failure

West Nile Disease Symptoms and Comorbidities: A Systematic Review and Analysis of Cases

West Nile virus (WNV) is a mosquito-borne flavivirus that has emerged as a major cause of viral encephalitis and meningitis, rarely leading to death. Several risk factors have been discussed in the past concerning the severity of the disease, while few reports have focused on precipitating conditions that determine of WNV-related death. Studies on cohorts of patients suffering of West Nile disease (WND) usually encompass low numbers of deceased patients as a result of the rarity of the event. In this systematic review and critical analysis of 428 published case studies and case series, we sought to evaluate and highlight critical parameters of WND-related death. We summarized the symptoms, comorbidities, and treatment strategies related to WND in all published cases of patients that included clinical features. Symptoms such as altered mental status and renal problems presented increased incidence among deceased patients, while these patients presented increased cerebrospinal fluid (CSF) glucose. Our analysis also highlights underestimated comorbidities such as pulmonary disease to act as precipitating conditions in WND, as they were significantly increased amongst deceased patients. CSF glucose and the role of pulmonary diseases need to be revaluated either retrospectively or prospectively in WND patient cohorts, as they may be linked to increased mortality risk.

Diaphragm impairment in patients admitted for severe COVID-19

Among patients affected by the virus COVID-19, physicians have observed ventilation disorders. It is relevant to assess neurological involvement, including the role of diaphragmatic function. Its possible impairment could be related to the systemic inflammatory response and disease progression that both typify COVID-19 infection. We distinguished two groups (severe group (SG) and mild group (MG)) according to the severity of respiratory symptomatology. We performed neurophysiological and sonography studies to evaluate the diaphragmatic function. Regarding the sonography variables, we identified statistically significant differences in the right mean diaphragmatic thickness along with the expiration, showing 1.56 mm (SEM: 0.11) in the SG vs 1.92 mm (SEM: 0.19) in the MG (p = 0.042). The contractibility of both hemidiaphragms was 15% lower in the severe group, though this difference is not statistically significant. In our examination of the neurophysiological variables, in the amplitude responses, we observed a greater difference between responses from both phrenic nerves as follows: the raw differences in amplitude were 0.40 μV (SEM: 0.14) in the SG vs 0.35 μV (SEM: 0.19) in the MG and the percentage difference was 25.92% (SEM: 7.22) in the SG vs 16.28% (SEM: 4.38%) in the MG. Although diaphragmatic dysfunction is difficult to detect, our combined functional and morphological approach with phrenic electroneurograms and chest ultrasounds could improve diagnostic sensitivity. We suggest that diaphragmatic dysfunction could play a relevant role in respiratory disturbance in hospitalised patients with severe COVID-19.

Unilateral Diaphragm Paralysis Associated With Neurosyphilis: A Case Report

Diaphragm dysfunction can originate from various etiologies, and bilaterality of the dysfunction depends on the cause. Symptoms of diaphragm dysfunction vary depending on the degree of phrenic nerve denervation, spinal cord lesion, and involvement of the diaphragm. Several infectious diaphragmatic dysfunctions have been reported, including the human immunodeficiency virus, poliovirus, West Nile virus, and dengue virus. Here, we report a case of unilateral diaphragm paralysis in a 34-year-old man with neurosyphilis.

Diaphragmatic paralysis: Evaluation in infants with congenital Zika syndrome

BACKGROUND

Paralysis of the diaphragm in newborn infants can lead to recurrent infections and life-threatening respiratory insufficiency. The clinical diagnosis of unilateral diaphragmatic paralysis has been reported in infants with laboratory evidence of congenital Zika virus infection and/or the congenital Zika syndrome (CZS) phenotype but no evaluation of phrenic nerve function has been described. All reported infants have had accompanying arthrogryposis. High infant mortality is reported.

METHODS

The causal mechanism of congenital diaphragmatic paralysis was evaluated in three infants with arthrogryposis as a manifestation of CZS (two of the three infants had laboratory evidence of ZIKV infection shortly after birth; the remaining infant had negative serology for ZIKV when first tested at 7 months of age). Electromyography and phrenic nerve compound muscle action potential (CMAP) were performed in all infants with diaphragmatic paralysis demonstrated on imaging studies.

RESULTS

All infants had evidence of moderate chronic involvement of peripheral motor neurons. Phrenic nerve CMAP was reduced on the side of the diaphragmatic paralysis in two infants and reduced bilaterally in the remaining infant who had primarily anterior involvement of the diaphragm. All three infants had multiple medical complications and one infant died at 18 months of age.

CONCLUSION

Evaluation of three infants with CZS and diaphragmatic paralysis demonstrated phrenic nerve dysfunction. In these and other affected infants, arthrogryposis appears to be a constant co-occurring condition and health problems are significant; both conditions are likely due to involvement of the peripheral nervous system in some infants with CZS.

Diaphragmatic Palsy

The diaphragm is the primary muscle of respiration, and its weakness can lead to respiratory failure. Diaphragmatic palsy can be caused by various causes. Injury to the phrenic nerve during thoracic surgeries is the most common cause for diaphragmatic palsy. Depending on the cause, the symptoms of diaphragmatic palsies vary from completely asymptomatic to disabling dyspnea requiring mechanical ventilation. On pulmonary function tests, there will be a decrease in the maximum respiratory muscle power. Spirometry shows reduced lung functions and a significant drop of lung function in supine position is typical of diaphragmatic palsy. Diaphragmatic movements with respiration can be directly visualized by fluoroscopic examination. Currently, this test is being replaced by bedside thoracic ultrasound examination, looking at the diaphragmic excursion with deep breathing or sniffing. This test is found to be equally efficient, and without risks of ionizing radiation of fluoroscope. Treatment of diaphragmatic palsy depends on the cause. Surgical approach of repair of diaphragm or nonsurgical approach of noninvasive ventilation has been tried with good success. Overall prognosis of diaphragmatic palsy is good, except when it is related to neuromuscular degeneration conditions.