Diaphragmatic Paralysis

Case Presentation

A middle aged businessman from Colombo, Sri Lanka was admitted with a four day history of high fever, retro-orbital pain, athralgia and myalgia. He had no cough on admission and did not complain of breathlessness. He denied any bleeding manifestations including passing black stools. He also denied any recent travel to Malaria endemic regions in the country but had recently traveled to China on a business visit. He had no previous co-morbidities of significance. His physical examination was unremarkable on admission apart from a body temperature of 38.4°Celsius. His full blood count revealed a total white blood cell count of 5000/mm³ with normal differentials, hemoglobin 17.4 g/dl with evidence of hemoconcentration (PCV 52%) and thrombocytopenia with a platelet count of 60,000/mm³. The platelet count dropped to a low of 20,000/mm³ before recovery but the patient did not develop any significant bleeding manifestations. Chest X-ray on admission was normal (Figure 1).

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Figure 1.

Chest X-Ray on admission.

Dengue fever was confirmed with a positive dengue polymerase chain reaction (PCR) result and positive Dengue IgM antibodies. He was managed with intravenous fluids according to national guidelines^[2] and was discharged from hospital following a 48 h afebrile period, good appetite and adequate platelet rise. Two days prior to discharge he developed a persistent dry cough, without fever. A repeat chest x-ray was performed but did not reveal any abnormalities and he was treated for acute bronchitis with bronchodilators and cough suppressants.

One month after discharge the patient was seen again, with complaints of a dry cough and breathlessness made worse with exertion (New York Heart Association Class III). The cough, which was present on initial discharge, had persisted but infrequently only to be continuous three days prior to the second admission. Orthopnoea was present but he did not complain of paroxysmal nocturnal dyspnoea. He had no wheezing, chest pain or palpitations. Physical examination at this point revealed normal vital parameters with decreased breath sounds in the right lung base with a stony dull percussion note. A chest x-ray was performed subsequently and showed an elevated right hemi-diaphragm (Figure 2).

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Figure 2.

Chest X-Ray one month after initial discharge.

Ultrasound scan chest did not reveal any pleural effusion but noted reduced diaphragmatic movements with respiration on the affected side. Contrast enhanced computed tomography (CECT) of the thorax did not reveal any lung parenchymal or mediastinal abnormalities. His lung function test revealed a sitting forced vital capacity of 2.11 L and supine 1.4 L (difference of 34%). He subsequently underwent nerve conduction studies of the phrenic nerves which revealed a decreased conduction amplitude on the right side suggestive of a demyelinating neuropathy, but was not suggestive of Guillain-Barre syndrome. There was no evidence of a neuromuscular junction disorder as suggested by normal electromyography. He was managed expectantly and spontaneously recovered within a few days of hospitalization and was discharged home. Repeat chest x-ray two weeks following discharge revealed that the hemidiaphragm was returning to normal position (Figure 3).