Critical Illness Polyneuromyopathy Presenting as Bulbar Palsy: A Case Report

Abstract

INTRODUCTION: Critical illness polyneuromyopathy is a clinical entity affecting critically ill patients. It affects the distal extremities and is characterized by generalized muscle atrophy causing considerable morbidity. Cases presenting with bulbar palsy are rare. A thorough clinical history and nerve conduction studies are vital in the diagnosis and rule out other neuromyopathies. CASE PRESENTATION: This is a case of a 58 year old female admitted due to four-day history of progressive dysphagia and dyspnea. She was hypertensive maintained on antihypertensives, blood thinners and statins. She had gouty arthritis with nephropathy and osteoarthritis given analgesics and steroids. On admission, she was stable. Baseline chest radiograph was clear. She underwent videofluoroscopic barium esophagram showing sluggish passage of contrast from the distal esophagus to the stomach, with to and fro movement of the contrast material within the distal esophagus, suggestive of motility dysfunction. On the seventh hospital day, she was referred to neurology service due to dysarthria, weak neck muscles (sternocleidomastoids and platysma) and upper extremities with flaccid paralysis. No sensory deficits were elicited. Patient was scheduled for electromyography -nerve conduction velocity and repetitive nerve stimulation studies which showed severe motor and sensory denervation of the limbs tested. Findings were compatible with critical illness polyneuropathy. Creatinine kinase total, and creatine kinase muscle isoenzyme were elevated. On the ninth hospital day, patient was intubated and placed at the ICU for septic shock from pneumonia. Inotropics and aggressive antibiotic therapy were given. Patient improved.She was referred to rehabilitation medicine.She was slowly weaned from the ventilator and extubated on the 22nd HD. She was discharged on the 34th HD with good phonation and articulation, tolerated regular diet and with improved muscle strength. DISCUSSION: Critical illness polyneuropathy (CIP), first described by Bolton and colleagues in 1986 affects motor and sensory axons. This can cause severe limb weakness and prolonged weaning from the ventilator. 1 Critical illness myopathy results from sepsis-related multiorgan failure, where widespread muscle weakness results from the endogenous myotoxic humoral factors produced during the innate immune response to sepsis. 2 Approximately 25% to 45% of patients admitted to the ICU develop Critical illness polyneuropathy, myopathy or polyneuromyopathy.In this patient CIP was confirmed by EMG-NCV and myopathy by elevated creatine kinase-muscle result. She presented with bulbar palsy, which is rare in critical illness polyneuromyopathy. Risk factors identified were sepsis which disturbs the microcirculation allowing the release of inflammatory mediators and passage of toxic substances and use of statins which inhibit cholesterol synthesis, decreasing concentrations of intermediates such as ubiquinone, resulting to intracellular lipid and sterol accumulation in muscle tissue. It also results in the reduction in mitochondrial number in myocytes leading to muscle weakness. 5 Other risk factors were use of steroids, female gender 6, renal failure, parenteral nutrition 7, and vasopressor use 9. Hyperglycemia is an independent risk factor thought to impair the microcirculation in the peripheral nerves. The proposed mechanism is multifactorial. The cytokines secreted in sepsis have histamine-like properties that increase microvascular permeability, resulting to endoneural edema and induce hypoxemia and energy depletion by increasing intercapillary distance. CONCLUSIONS: Critical illness polyneuromyopathy is a crucial condition which warrants close attention to decrease morbidity and mortality in critically-ill patients.