Before Blaming Myosarcoidosis for Respiratory Insufficiency, Cerebral Involvement and Other Causes Should Be Ruled Out

Abstract

To the Editor We read with interest the article by Aritake et al. on a 66-year-old woman with sarcoidosis who was admitted due to confusion and dyspnea with hypercapnia secondary to myosarcoidosis (nodular plus myopathic type) (1).The patient received prednisolone and had an incomplete recovery until discharge on hospital day 35 (1).Several points should be considered in this regard.First, cerebral imaging was not performed at the age of 66 years (1).Although the patient had hypercapnia, other causes of confusion, especially cerebral involvement in sarcoidosis, should be ruled out in such cases (2).Normal cerebral computed tomography (CCT) at the age of 65 years does not exclude the possibility that the patient had developed cerebral involvement in sarcoidosis one year later, namely at the age of 66 years.Furthermore, CCT is generally unsuitable for documenting cerebral involvement in sarcoidosis.Cerebral magnetic resonance imaging (MRI) is critical for ruling out the possibility of cerebral sarcoidosis due to respiratory insufficiency.Neurosarcoidosis occurs in 5-25% of all systemic sarcoidosis cases (3).The most common manifestation of neurosarcoidosis in the central nervous system (CNS) is leptomeningeal thickening, particularly at the base of the brain (3).To exclude neurosarcoidosis, it would be useful to examine the cerebrospinal fluid (CSF).The second point is that positron emission tomography (PET) at the age of 65 years does not convincingly show involvement of the intercostal muscles and erector spinae in sarcoidosis (1).Did the diaphragm function normally?To assess muscle involvement, it would have been useful to perform needle electromyography, muscle MRI with contrast to rule out myositis, or even muscle biopsy.The third point relates to the discrepancy between the statement that the patient was admitted due to confusion and dyspnea, and the description of the clinical examination was identified as "normal breathing."(1) This discrepancy needs to be clarified.Since the patient had hypercapnia, it is unlikely that she had normal breathing on admission.