Diaphragmatic Flutter: A Rare Cause of Intermittent Upper Abdominal Fluttering
The most likely diagnosis is diaphragmatic flutter (van Leeuwenhoek's disease), a rare disorder characterized by rapid rhythmic involuntary contractions of the diaphragm that manifest as visible abdominal wall movements alternating between sides. 1, 2
Clinical Presentation and Diagnosis
The hallmark features of diaphragmatic flutter include:
- Involuntary rhythmic movements in the chest and upper abdomen that are visible and palpable 1, 2
- Intermittent nature with episodes that can be triggered by specific activities or occur spontaneously 3, 4
- Alternating or predominantly unilateral abdominal wall movements, though bilateral involvement is common 1
- Associated symptoms may include dyspnea, thoracoabdominal pain, and respiratory discomfort 2, 3, 5
The diagnosis is confirmed by diaphragmatic fluoroscopy showing high-frequency flutter and electromyography (EMG) demonstrating repetitive discharges at 0.5-15 Hz superimposed on normal respiratory activity. 1, 2, 5
Diagnostic Workup
Essential Studies
- Diaphragmatic fluoroscopy is the gold standard imaging test to visualize the rapid involuntary diaphragmatic contractions 1
- EMG of respiratory muscles (diaphragm, scalene, and parasternal intercostal muscles) reveals characteristic repetitive discharges at frequencies of 0.5-15 Hz 2, 5
- Spirographic tracings show high-frequency oscillations superimposed on normal tidal respiratory movements 5
Neuroimaging Considerations
- Brain MRI should be obtained to exclude secondary causes, particularly stroke or posterior fossa lesions, as diaphragmatic flutter can occur after cerebrovascular events 1
- The origin of abnormal discharges may be in the central nervous system, and psychosomatic factors can participate in disease development 2
Important Clinical Caveats
Do not confuse this with functional dyspepsia or gastroesophageal reflux disease, which present with pain or discomfort but not visible rhythmic movements 6. The visible fluttering movements are pathognomonic for diaphragmatic flutter and distinguish it from other causes of upper abdominal symptoms.
This is not a biliary or hepatic disorder requiring ultrasound or MRCP as first-line imaging 7, 8, 9. While these modalities are appropriate for colicky RUQ pain with elevated liver enzymes, they will not diagnose diaphragmatic flutter.
Treatment Approach
First-Line Medical Therapy
Carbamazepine 200-400 mg three times daily is the most effective medical treatment, leading to disappearance or great improvement of flutter and clinical symptoms. 5 This anticonvulsant medication suppresses the abnormal neural discharges responsible for the involuntary diaphragmatic contractions.
Alternative and Refractory Cases
- Noninvasive ventilatory support (NVS) using mouthpiece or nasal ventilation can instantaneously halt flutter by resting the diaphragm 3
- Phrenic nerve crush may be considered for highly symptomatic patients refractory to medical therapy, though success is variable 1, 3
- Diaphragm pacer stimulation has been attempted but shown limited effectiveness 3
Differential Considerations
While diaphragmatic flutter is the primary diagnosis to consider, also evaluate for:
- Abdominal wall muscle spasms which can cause similar cramping but typically lack the high-frequency rhythmic quality 4
- Hiccups or belching which may coexist with high-frequency diaphragmatic flutter 5
- Secondary causes including stroke, particularly involving the cerebellum or occipitotemporal regions 1
The key distinguishing feature is the visible, rapid, rhythmic abdominal wall movement that can alternate between sides—a finding unique to diaphragmatic flutter and not seen in other abdominal disorders.