Tag: creatine kinase

Sonographic Diaphragm Abnormalities are an Unexpectedly Frequent Feature of Long COVID Outpatients with Unexplained Dyspnea and Fatigue

Abstract:

Purpose: The primary aim of this study is to define the sonographic diaphragm phenotype of Long COVID rehabilitation outpatients with non-specific dyspnea and fatigue. We analyzed patients referred from a pulmonary post-COVID clinic that were lacking a specific cardiopulmonary diagnosis for their symptoms. Additionally, we report the functional outcomes of subset of patients who completed an outpatient cardiopulmonary physical therapy program.

Methods: This was a retrospective cohort study (n = 58) of consecutive patients referred for neuromuscular ultrasound assessment of diaphragm muscle using B-mode technique. Patients were recruited from a single academic hospital between February 25, 2021 and November 22, 2022.

Results: Sonographic abnormalities were identified in 57% (33/58) of patients, and in the vast majority of cases (33/33) was defined by a low diaphragm muscle thickness. Thinner diaphragm muscles are correlated with lower serum creatinine and creatine kinase values, but there was no association with markers of systemic inflammation. Thirty three patients participated in outpatient cardiopulmonary physical therapy that included respiratory muscle training, and 75.8% (25/33) had documented improvement.

Conclusion: In the outpatient rehabilitation setting, patients with Long COVID display low diaphragm muscle thickness, but intact muscle contractility, with surprising frequency on neuromuscular ultrasound. We speculate this represents a form of disuse atrophy. Also, these patients appear to have a favorable response to cardiopulmonary physical therapy that includes respiratory muscle training.

Source: Prabhav P. Deo, Joseph I. Bailey, Alexandra S. Jensen, Ellen Farr, Meghan Fahey, Matthew Isherwood, Keerthana Chakka, Lisa F. Wolfe, Ishan Roy, Marc A. Sala, Colin K. Franz. Sonographic Diaphragm Abnormalities are an Unexpectedly Frequent Feature of Long COVID Outpatients with Unexplained Dyspnea and Fatigue. medRxiv 2022.06.29.22277054; doi: https://doi.org/10.1101/2022.06.29.22277054 (Full text)

Use of dynamic tests of muscle function and histomorphometry of quadriceps muscle biopsies in the investigation of patients with chronic alcohol misuse and chronic fatigue syndrome

Abstract:

Ischaemic lactate/ammonia tests, serum carnosinase and creatine kinase assays and percutaneous needle muscle biopsies were performed on 10 patients with chronic fatigue syndrome (CFS), and 10 with chronic alcohol misuse complaining of muscular symptoms.

Basal serum lactate levels were significantly elevated in the alcohol misusers compared to the CFS patients, but all were within the reference range. Lactate profiles after ischaemic forearm exercise did not differ significantly for the two patient groups.

In one patient previously diagnosed as having CFS, myoadenylate deaminase deficiency was identified on the basis of a flat ammonia response to ischaemia and absent muscle adenosine monophosphate deaminase activity. In addition, two further patients in the CFS group were subsequently shown to have other disorders: one had polymyositis and one had myopathy with mild type II fibre atrophy of unknown cause.

Histomorphometric examination of muscle needle biopsy in the alcohol misusers showed features of chronic alcohol-induced skeletal myopathy in six patients and polymyositis in one patient. Type II fibre atrophy factors were significantly elevated in the alcohol group but were within the reference range in CFS patients.

Dynamic tests of muscle function and muscle histology are valuable tools in excluding alternative pathology in CFS, whereas muscle histomorphometry is of the greatest value in the diagnosis of chronic alcoholic myopathy.

 

Source: Wassif WS, Sherman D, Salisbury JR, Peters TJ. Use of dynamic tests of muscle function and histomorphometry of quadriceps muscle biopsies in the investigation of patients with chronic alcohol misuse and chronic fatigue syndrome. Ann Clin Biochem. 1994 Sep;31 ( Pt 5):462-8. http://www.ncbi.nlm.nih.gov/pubmed/7832572

 

Biochemical and muscle studies in patients with acute onset post-viral fatigue syndrome

Abstract:

AIMS: To investigate in detail various biochemical and pathophysiological indices of muscle pathology in acute onset post-viral fatigue syndrome (PVFS).

METHODS: Twenty three patients with PVFS (of mean duration 4.6 years) were subjected to needle biopsy for histomorphometry and total RNA contents. Plasma analysis included serology and creatine kinase activities. Indices of whole body mass were also measured–namely, whole body potassium content and plasma carnosinase activities.

RESULTS: About 80% of the patients had serology indicative of persistent enteroviral infection as determined by VP1 antigen assay. Only about 10% of that same group of patients had serological indications of current enterovirus infection by IgM assay; a separate subset of 10% showed antibody changes suggestive of reactivation of Epstein-Barr virus. Quantitative morphometric analysis of skeletal muscle fibres indicated that the quadriceps muscle was normal or displayed only minor abnormalities in 22 patients. The Quetelet’s Index (body mass index) and whole-body potassium values (index of lean body mass) were not affected in PVFS. The mean plasma carnosinase and creatinine kinase activities were also generally normal in these patients. The mean muscle RNA composition–mg RNA/mg DNA: was significantly reduced in acute onset PVFS by about 15%. The protein:DNA ratio was not significantly affected.

CONCLUSIONS: Patients with acute onset PVFS, therefore, lose muscle protein synthetic potential, but not muscle bulk. Histopathology is consistent with these observations. These perturbations may contribute to the apparent feature of perceived muscle weakness associated with the persistent viral infection in the muscle themselves.

 

Source: Preedy VR, Smith DG, Salisbury JR, Peters TJ. Biochemical and muscle studies in patients with acute onset post-viral fatigue syndrome. J Clin Pathol. 1993 Aug;46(8):722-6. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC501456/

 

Chronic fatigue: electromyographic and neuropathological evaluation

Abstract:

Single fibre electromyography of extensor digitorum communis muscle (EDC) was performed on 35 patients with chronic fatigue, the majority of whom also had creatine kinase estimation and biopsy of EDC.

The subjects were categorised as having an acute-onset post-viral fatigue syndrome, a non-specific chronic fatigue or possible muscle disease in view of pronounced myalgia.

Of 11 subjects who had myalgia as a significant symptom, abnormalities in fibre density were found in 6, and 5 of these had some non-specific abnormalities on muscle biopsy, with creatine kinase levels being normal in all cases. Fibre density estimation may be a useful way of identifying a subgroup of chronic fatigue sufferers with a possible primary muscle disorder.

 

Source: Connolly S, Smith DG, Doyle D, Fowler CJ. Chronic fatigue: electromyographic and neuropathological evaluation. J Neurol. 1993 Jul;240(7):435-8. http://www.ncbi.nlm.nih.gov/pubmed/8410086