Rectus abdominis rhabdomyolysis after sit ups: unexpected detection by bone scan

Abdominal Crunch Syndrome Creates a -Diagnostic Challenge in Treating a Pilot with Acute Upper -Abdominal Pain

BACKGROUND: A diagnosis in acute abdomen may remain elusive especially when the cause is rare. We report this interesting case of a fighter pilot presenting with acute abdominal pain. The case posed significant challenges in reaching the correct diagnosis of abdominal crunch syndrome. The syndrome is rare with only seven reports in the literature so far. To the best of our knowledge, this is the first ever report of this condition in an aircrew.CASE REPORT: A 37-yr-old pilot presented with severe upper abdominal pain and sweating. During examination, he developed bradycardia and was admitted with a presumptive diagnosis of acute coronary syndrome. Investigations revealed no myocardial ischemia on ECG, transaminitis, raised CPK, CKMB, and LDH. A CECT scan of chest and abdomen was normal. A GI surgery consult was sought where we connected the transaminitis and raised CPK and considered the possibility of rhabdomyolysis. On specific inquiry, the aviator gave history of unaccustomed exercise with a vigorous session of abdominal crunches a day prior. Thus, a diagnosis of abdominal crunch syndrome was concluded.DISCUSSION: The aviator did not associate his vigorous exercise with the occurrence of pain and, therefore, did not mention it. It would have avoided unnecessary investigations and delay in treatment. From the aeromedical safety aspect, had the aviator flown on the day he developed pain, there was a possibility of developing severe pain exacerbated by the G force and G suit and sudden in-flight incapacitation. From the perspective of the aircrew, it is advisable that they avoid sudden, unaccustomed exercise.Kumar A, Kaistha S. Abdominal crunch syndrome creates a diagnostic challenge in treating a pilot with acute upper abdominal pain. Aerosp Med Hum Perform. 2023; 94(2):86-89.

Perspectives on Exertional Rhabdomyolysis

Exertional (exercise-induced) rhabdomyolysis is a potentially life threatening condition that has been the subject of research, intense discussion, and media attention. The causes of rhabdomyolysis are numerous and can include direct muscle injury, unaccustomed exercise, ischemia, extreme temperatures, electrolyte abnormalities, endocrinologic conditions, genetic disorders, autoimmune disorders, infections, drugs, toxins, and venoms. The objective of this article is to review the literature on exertional rhabdomyolysis, identify precipitating factors, and examine the role of the dietary supplement creatine monohydrate. PubMed and SPORTDiscus databases were searched using the terms rhabdomyolysis, muscle damage, creatine, creatine supplementation, creatine monohydrate, and phosphocreatine. Additionally, the references of papers identified through this search were examined for relevant studies. A meta-analysis was not performed. Although the prevalence of rhabdomyolysis is low, instances still occur where exercise is improperly prescribed or used as punishment, or incomplete medical history is taken, and exertional rhabdomyolysis occurs. Creatine monohydrate does not appear to be a precipitating factor for exertional rhabdomyolysis. Healthcare professionals should be able to recognize the basic signs of exertional rhabdomyolysis so prompt treatment can be administered. For the risk of rhabdomyolysis to remain low, exercise testing and prescription must be properly conducted based on professional standards.

Increased Prevalence of the IL-6-174C Genetic Polymorphism in Long Distance Swimmers

The IL-6 -174G/C single nucleotide polymorphism (SNP) functionally affects IL-6 activity, with the G-allele associated with increased IL-6 levels. The C-allele was found to be associated with exercise-induced skeletal muscle damage. The aim of the present study was to examine the association between the IL-6 -174G/C polymorphism and athletic performance among elite swimmers and runners. The study sample included 180 track and field athletes and 80 swimmers. Track and field athletes were assigned to three sub-groups: long-distance runners, middle-distance runners and short-distance runners. Swimmers were assigned to two subgroups: long-distance swimmers and short-distance swimmers. The control group consisted of 123 non-athletic healthy individuals. Genomic DNA was extracted from peripheral blood following a standard protocol. Genotyping was performed using polymerase chain reaction (PCR). The CC genotype and C-allele frequency were significantly higher in the long-distance swimmers (18 and 43%, respectively) compared to the long-distance runners (3 and 14%, respectively, p < 0.001); middle-distance runners (4 and 22%, respectively, p < 0.001); and controls (5 and 19%, respectively, p < 0.001). In addition, the CC genotype and C-allele frequency were significantly higher (p < 0.001) in long-distance swimmers compared to short-distance swimmers (18 versus 5% and 43 versus 29% for the CC genotype and C-allele frequency, respectively). The higher frequency of the C-allele and CC genotype among long-distance swimmers suggests that the rarity of exercise-associated rhabdomyolysis among swimmers is probably related to other sports-specific or water-related protective mechanisms. It is possible that swimming selection in talented endurance athletes who are C-allele carriers represents an example of genetically-dependent sports selection.

Extraosseous Findings on Bone Scintigraphy Using Fusion SPECT/CT and Correlative Imaging

OBJECTIVE

Extraosseous radioactivity outside of the expected biodistribution is often encountered on (99m)Tc-methylene diphosphate (MDP) bone scintigraphy, and proper interpretation requires an understanding of the mechanisms underlying this uptake and knowledge of the possible causes, depending on the site or structure involved.

CONCLUSION

We present examples of extraosseous radiotracer uptake seen on (99m)Tc-MDP bone scans in which either SPECT with integrated CT or correlative imaging improved the study's interpretation.

Rhabdomyolysis: a review, with emphasis on the pediatric population

Rhabdomyolysis is a common clinical syndrome and accounts for 7% of all cases of acute kidney injury (AKI) in the USA. It can result from a wide variety of disorders, such as trauma, exercise, medications and infection, but in the pediatric population, infection and inherited disorders are the most common causes of rhabdomyolysis. Approximately half of patients with rhabdomyolysis present with the triad of myalgias, weakness and dark urine. The clinical suspicion, especially in the setting of trauma or drugs, is supported by elevated creatinine kinase levels and confirmed by the measurement of myoglobin levels in serum or urine. Muscle biopsy and genetic testing should be performed if rhabdomyolysis is recurrent or metabolic myopathy is suspected. Early recognition is important to prevent AKI through the use of aggressive hydration. Prevention is important in patients with inherited forms, but novel therapies may be developed with the better understanding of the pathophysiology and genetics of rhabdomyolysis.

The "bat sign" of pectoral rhabdomyolysis

A 22-year-old man with foot pain was referred for evaluation of sesamoiditis. A Tc-99m methylene-diphosphonate bone scan was performed which revealed increased radiopharmaceutical uptake in the big toes, but also showed curious abnormal thoracic activity. Normal activity at sternoclavicular joints and sternum mimics ears, head and body of a bat, and the pectorals mimic the wings. The patient mentioned that he had started lifting weights a few days earlier. Clinical and echographic evaluations were diagnostic of pectoral inflammation suggesting rhabdomyolysis.

What is the value of Tc-99m hydroxymethylene diphosphonate scintigraphy for the etiological diagnosis of mild rhabdomyolysis?

AIMS

We tested whether bone scintigraphy could help in the etiological diagnosis in patients with mild rhabdomyolysis, because different patterns of soft tissue radiotracer uptake have been found on bone scintigraphy in patients presenting with severe rhabdomyolysis, with a localized asymmetric pattern in traumatic lesions and a more diffuse and symmetric pattern in nontraumatic lesions. However, the performance of bone scintigraphy in mild rhabdomyolysis is unknown. The etiological diagnosis of rhabdomyolysis can be difficult, particularly in alcohol abusers who deny a recent alcoholic binge.

MATERIAL AND METHODS

Bone scintigraphy was performed in 16 patients presenting with acute renal failure secondary to mild rhabdomyolysis (creatinine kinase levels < or =36,000 IU), with obvious causes in 10 cases and with uncertain etiologies in the remaining 6 patients.

RESULTS

In 5 cases with evident traumatic rhabdomyolysis, and in 4 patients with uncertain etiologies, bone scintigraphy showed localized asymmetric soft tissue radiopharmaceutical uptake compatible with traumatic lesions. None of the 5 patients with nontraumatic rhabdomyolysis had significant soft tissue radiopharmaceutical uptake. In 1 patient with traumatic rhabdomyolysis, bone scintigraphy performed only 11 days after the initial insult was negative. One patient with an uncertain etiology also had a negative scintigraphy.

CONCLUSIONS

Bone scintigraphy, when performed early in the course of the disease, may contribute to the etiological diagnosis of rhabdomyolysis if it shows asymmetric localized soft tissue radiopharmaceutical uptake compatible with traumatic lesions. However, bone scintigraphy is often negative in mild nontraumatic lesions.

Rhabdomyolysis induced by psychotropic drugs

A 41-year-old man experienced continuous convulsions, unconsciousness, and a high temperature. His laboratory findings revealed an increase in serum creatine phosphokinase, serum myoglobulin, and urinary myoglobulin levels. He had taken many psychotropic drugs as treatment for schizophrenia and was very dehydrated. Because a diagnosis of rhabdomyolysis was suspected, Tc-99m HMDP bone scintigraphy was performed. It showed diffusely increased soft tissue uptake in his shoulder girdles, vertebral area, psoas iliac muscles, and gluteofemoral muscles, leading to a diagnosis of rhabdomyolysis. Bone scintigraphy is useful in making an early diagnosis and evaluating the location and degree of muscle injury in rhabdomyolysis.

Exertional rhabdomyolysis: early recognition is key

Exertional rhabdomyolysis is an uncommon diagnosis, but because its complications can be severe, clinicians need a thorough understanding of this syndrome. When skeletal muscle cell membranes are damaged, their intracellular contents enter the bloodstream and can cause potentially serious sequelae, even death. Intense exercise, some viral infections, and certain genetic disorders increase the risk. Serum creatine kinase levels are the diagnostic gold standard. The treatment of rhabdomyolysis consists of early detection, therapy for the underlying cause, measures to prevent renal failure, and correction of metabolic complications.

Myoglobinuria

Myoglobinuria refers to an abnormal pathologic state in which an excessive amount of myoglobin is found in the urine, imparting a cola-like hue, usually in association with myonecrosis and a clinical picture of weakness, myalgias, and edema. Myoglobinuria is produced by multiple causes: any condition that accelerates the use or interferes with the availability of oxygen or energy substrates to muscle cells can result in myoglobinuria, as can events that produce direct muscle injury, either mechanical or chemical. Acute renal failure is the most serious complication, which can be prevented by prompt, aggressive treatment. In patients surviving acute attacks, recovery of muscle and renal function is usually complete.