Central nervous system involvement in patients with critical illness polyneuropathy

Weaning difficulty after severe pneumonia in adult-onset mitochondrial myopathy with A3243G mutation in the mitochondrial tRNA gene: A case report

Background

Mitochondrial myopathy is a group of diseases caused by abnormal mitochondrial structure or function. The mitochondrial myopathy impacts muscles of the whole body and exhibits variable symptoms. Respiratory muscle deficits deteriorate pulmonary function in patients with severe pneumonia.

Case presentation

We report the case of a male patient with severe pneumonia-induced respiratory failure. He was abnormally dependent invasive ventilator-assisted ventilation after his condition had improved. Then we found abnormal ventilator waveform and a decline in muscle strength of him. Mitochondrial myopathy was ultimately confirmed by muscle pathological biopsy and body fluid genetic testing. Vitamin B complex, coenzyme Q10, Neprinol AFD, l-arginine, and MITO-TONIC were used to improve mitochondrial function and muscle metabolism. After treatment, discomfort associated with chest tightness, fatigue, cough, and sputum disappeared, and the patient was discharged.

Conclusion

This case presented an uncommon cause of difficult weaning and extubation-acute onset of mitochondrial myopathy. Muscle biopsy and genetic testing of body fluid are essential for diagnosing mitochondrial myopathy. The A3243G mutation in the MT-TL1 gene of mitochondrial DNA contributes to pathogenesis of this case.

Intensive Care Unit-Acquired Weakness: Neuropathology

There is extensive evidence in the literature that both peripheral nerve fibers and muscle fibers are affected in the course of intensive care unit-acquired weakness. Peripheral nerve lesion is characterized by axonal degeneration, without inflammatory changes. Muscle fiber involvement is characterized by muscle fiber atrophy and loss of thick filaments, predominantly involving type 2 fibers, but myonecrosis ("acute necrotizing myopathy of intensive care") has also been reported. Steroids can precipitate thick myofilament damage, probably to some extent also triggered by immobilization and neuromuscular junction blockade. Sepsis and a systemic inflammatory response cause muscle fiber injury because of the release of cytokines and chemokines that modulate enzymatic reactions related to proteolysis. Regarding axonal injury, hyperglycemia, hypoalbuminemia, inflammatory response, and hypoperfusion are accepted risk factors. Nerve and muscle biopsy are the best methods for detection of structural abnormalities, but these are invasive investigations; although not suitable for repeated studies, in selected cases, biopsies may have a role in diagnosis.

Fulminant Guillain-Barré Syndrome and Spontaneous Intraventricular Hemorrhage: A Case Report and Literature Review

Guillain–Barré syndrome (GBS) is an acute, immune-mediated inflammatory peripheral polyneuropathy that is characterized by flaccid paralysis. A few cases have reported that GBS can be caused by head trauma or neurosurgery, but it has never been associated with intraventricular hemorrhage. Here, we report an uncommon case of fulminant GBS that occurred after spontaneous intraventricular hemorrhage. A 73-year-old woman was admitted to the hospital after sudden unconsciousness and vomiting. A head computed tomography (CT) scan following the incident showed a newly developed intraventricular hemorrhage, which led to an immediate ventriculostomy. After 5 days, the endotracheal tube was removed. Two days later, the external ventricular drainage tube was also removed. At this time, the patient was alert and the neurological examination was normal. However, the patient suddenly presented with acute respiratory failure and bilateral limb weakness 3 days later. An analysis of the patient’s cerebrospinal fluid (CSF) revealed that albuminocytologic dissociation was present. The patient was treated with intravenous immunoglobulin (0.4 g/kg/day) for 5 days. Despite timely medical intervention in the hospital, the patient passed away 2 months later. After a cerebral hemorrhagic injury, limb and respiratory muscle weakness can occur on occasion in the ICU. In this context, the potential involvement of GBS should not be ignored. Importantly, the pathogenic mechanism of GBS has been discussed for over a century, and it still remains a mystery. We speculate that the TLR4/NF-κB signaling pathway may be involved in the pathogenesis of GBS following intraventricular hemorrhage. The prognosis of most patients with GBS is usually good, but cerebral hemorrhage and mechanical ventilation may serve as risk factors that exacerbate the condition. This case is reported to remind clinicians to consider the possibility of GBS when patients present limb and respiratory muscle weakness after intraventricular hemorrhage, and to provide a starting point to discuss potential mechanisms of GBS after intraventricular hemorrhage.