What is Man in a Barrel Syndrome?
Man in a barrel syndrome (MIBS) is a condition affecting the nervous system. It results in weakness in both arms while allowing normal strength in the face, neck, and legs. Imagine someone stuck in a barrel with only their head and lower body sticking out and that’s what it looks like for a person with MIBS – their arms are affected but they can move normally in other ways.
MIBS can come from different types of damage to parts of the brain that control arm movement. It’s also seen after injuries to the brain stem, the upper part of your spine, the network of nerves in your shoulder (brachial plexus), or nerves in other areas.
A common cause of MIBS is systemic hypotension that leads to specific types of strokes called watershed strokes. These types of strokes occur in the “border zones” between the areas of the brain supplied by different arteries. When your blood pressure is so low that it can’t supply enough blood to these small arteries at the brain’s border zones, the cells in these areas don’t get the oxygen-rich blood they need and they die. Conditions like cardiac arrest, where blood flow to the brain is impaired, can also cause MIBS.
What Causes Man in a Barrel Syndrome?
‘Man in a Barrel Syndrome’ can occur when both sides of the brain do not get enough blood. This often happens when there is low blood pressure throughout the body like during a cardiac arrest.
The internal carotid artery is a major blood vessel that delivers blood to the front two-thirds of our brain through two other arteries, the anterior cerebral artery (ACA) and the middle cerebral artery (MCA). These arteries reach out to different parts of the brain, including the nerves that control arm movements. If there isn’t enough blood reaching both sides of the brain, the farthest reaching parts of these arteries, known as watershed zones, will not get enough oxygen-rich blood. This causes the cells in these regions to die. Because of the layout of the brain, any damage to these regions can cause weakness in both arms.
It’s important to note that any injury that affects both the nerves responsible for arm movement can cause similar symptoms of weakness in both arms. This includes bleeding, inflammation, traumatic injury, or disease like tumors and cancer that have spread to other parts of the body.
Acute shortage of blood supply in the part of the brain or neck that contains the fibers responsible for arm movements can cause ‘Man in a Barrel Syndrome’ too. Similarly, injury or conditions that compress these fibers in the neck, yet leaving those for leg movements untouched, can produce the same effect. Conditions affecting peripheral nerves (nerves outside the brain and spinal cord) that control arm movements or where these nerves meet the muscles can also cause this syndrome.
Risk Factors and Frequency for Man in a Barrel Syndrome
Man in a Barrel Syndrome, or MIBS, is a rare condition and we don’t know exactly how often it occurs. It affects both men and women. The most frequent cause of MIBS is a type of stroke, more specifically a “watershed stroke,” which happens due to reduced blood flow to the brain. Despite this, watershed strokes account for just 10% of all strokes caused by blood flow issues.
Signs and Symptoms of Man in a Barrel Syndrome
Diagnosing ‘Man In a Barrel Syndrome’ (MIBS) begins with a detailed personal background and a neurological test. Particular focus is on if weakness is observed in both arms while facial, cervical, and leg strength remains unaffected.
The neurological exam of a MIBS patient typically shows weakness in both arms and maintains normal strength in the neck and lower body parts. Depending on where the neurological damage is located, the patient’s mental state could range from normal to severely impaired.
- Patients with brain or neck spine injury causing MIBS often have quick reflexes.
- However, if MIBS is caused by problems with the peripheral nervous system such as multiple motor neuropathy, myasthenia gravis, or bilateral brachial plexus injuries, the reflexes are usually slow or not present.
After diagnosing MIBS from the neurological exam, the next step is to identify the injury causing it. History can hint the location of the injury.
- For example, if MIBS follows a cardiac arrest where the heart stopped for an extended period, it suggests that there may have been bilateral watershed strokes.
- If the person had a recent neck injury, it may indicate a cervical spine lesion, or if an injury involved both upper arms, it can suggest bilateral brachial plexus injury.
- Recent surgery involving arm traction could suggest a problem with both brachial plexus.
Testing for Man in a Barrel Syndrome
If your doctor suspects you have a condition called MIBS, which leads to weakness in both upper arms simultaneously, they will perform a series of tests. These tests aim to identify the exact spot causing the issue.
The primary tests include brain imaging, using techniques such as magnetic resonance imaging (MRI) or computed tomography (CT). These can reveal any areas in the brain that have suffered damage due to a lack of oxygen (ischemic), bleeding (hemorrhagic), cancer spread to the brain (metastatic), or inflammation. An MRI or CT of your neck (cervical spine) can also help locate any issues potentially causing pressure on your spinal cord.
If these tests can’t find the cause of your MIBS, your doctor may examine your brachial plexus next. The brachial plexus is a network of nerves running from your spine to your shoulder and arm. An MRI can detect damage to these nerves, and a test called electromyography (EMG) can pinpoint the exact location of the nerve root, brachial plexus, or peripheral nerve that’s not functioning correctly.
A common cause of MIBS is a ‘watershed stroke’ – named so because it affects the vulnerable ‘watershed’ areas of the brain located between the major arteries. If you have had this type of stroke, your physician will perform an examination of your arteries in your neck and head to look for narrow spots. If they find any significant narrowings in your internal carotid arteries – two major blood vessels in your neck that supply your brain with blood – procedures like a carotid endarterectomy or stent placement may help. These procedures can widen the narrow arteries and reduce the risk of another stroke.
Treatment Options for Man in a Barrel Syndrome
Treatment for ‘man in a barrel syndrome’, a condition causing weakness in the arms and shoulders, can vary greatly depending on the source and type of nerve injury.
For individuals who have suffered a certain kind of stroke, known as a watershed stroke, treatment usually involves several steps. Firstly, their blood pressure needs to stay within a healthy range to prevent the stroke from getting worse. They will also need to be screened for any narrowing of the arteries, which may have led to a lack of blood flow to the brain causing the stroke. Medication to stop blood clots (antithrombotic medication) may be started, and if there are any identified causes of low blood pressure, these should be corrected.
For those with ‘man in a barrel syndrome’, caused by pressure on the neck part of the spine, immediate surgery to reduce this pressure could be considered. If the condition is due to inflammation in the cervical spine, steroids might be used to help reduce this inflammation.
In all cases, physical therapy and occupational therapy play essential roles in improving the functioning of the arms and hands. This supportive treatment is crucial in helping individuals regain as much independence as possible, and to improve their overall quality of life.
What else can Man in a Barrel Syndrome be?
When doctors are trying to diagnose man in a barrel syndrome, there are a few different conditions that may seem similar but are actually different. They will consider the following:
- Issues with the nerve pathways in both arms, which could be due to a variety of issues like stroke, injury, inflammation or cancer spreading
- Problems with the neck spine, for example from external pressure, insufficient blood supply, inflammation or infection
- Damage to the nerve networks in both shoulders, possibly due to physical injuries or inflammation
- Problems with the peripheral nerves, which could be due to damage by toxins or metabolism issues, inflammation, or autoimmune conditions like multifocal motor neuropathy or myasthenia gravis
What to expect with Man in a Barrel Syndrome
The outlook for ‘man in a barrel syndrome’ is determined by the type and position of the damage in the body. The syndrome is associated with a varying recovery rate for individuals who’ve had bilateral watershed strokes – a condition arising from an insufficient supply of oxygen to the brain – depending on the extent of the damage caused due to lack of oxygen.
In cases where individuals with ‘man in a barrel syndrome’ are unconscious due to extensive watershed strokes, survival rates fall below 10%. On the other hand, those suffering from bilateral intracerebral hemorrhage – a condition involving bleeding within the brain – generally face a challenging outlook, but this can also depend on the extent of damage to brain tissues.
Recovery from ‘man in a barrel syndrome’ caused by compression of the cervical spine – the region of your spine located in the neck – is influenced by how swiftly this compression is detected and treated surgically. For those where the syndrome results from myasthenia gravis – a chronic autoimmune neuromuscular disease that weakens the skeletal muscles – the syndrome can be fully reversible with treatment for myasthenia gravis.
Possible Complications When Diagnosed with Man in a Barrel Syndrome
After damaging both sides of the brain, one might experience problems with memory, sensation, language skills, strength, and tightness in the muscles. The complications of an injury to the neck portion of the spinal cord might involve weakness, sensory loss, muscle stiffness, and problems with bowel and bladder control. If both brachial plexus nerves, which supply the upper arms, are injured, it may result in both movement and feeling loss in both upper limbs.
Possible Complications:
- Problems with memory
- Sensation loss
- Language skill difficulty
- Weakening of strength
- Tightness in muscles
- Weakness from neck injury
- Bowel and bladder control issues
- Movement and feeling loss in both upper limbs
Preventing Man in a Barrel Syndrome
If you have MIBS (Multiple Intracranial Bifurcation Syndromes), it’s important to understand the cause of your condition. It could be due to various factors, such as a stroke, tumor, spreading cancer (metastasis), an auto-immune reaction (where your body’s immune system attacks health cells) or inflammation (swelling and redness). Understanding the root cause of your MIBS is crucial as it will determine the type of treatment you’ll receive.
