Brainstem Stroke: Head Ct Scan Detection

Brainstem strokes are life-threatening and require immediate medical attention. Brainstem strokes are often difficult to diagnose because they do not always show up on CT scans. CT scans are often one of the first tests performed in a stroke evaluation, and they can help determine if abnormalities in the brain are caused by insufficient blood flow (ischemic stroke) or a ruptured blood vessel (hemorrhage). However, CT scans may not always detect a stroke, especially if it has occurred in areas that the scan does not image well, such as the brainstem.

Other imaging tests, such as magnetic resonance imaging (MRI), can also be used to identify the cause and location of the stroke and assess blood flow in the brain. These tests are crucial for prompt diagnosis and treatment, which are essential for limiting brain stem damage and improving the chances of recovery.

Brainstem stroke symptoms

A brainstem stroke occurs when there is damage to the brainstem, which is located at the base of the brain and connects the brain to the spinal cord. The brainstem controls many of the body's basic functions, including breathing, heart rate, blood pressure, consciousness, and motor control. Brainstem strokes can be particularly damaging and even deadly.

The two main types of brainstem stroke are ischemic and hemorrhagic. An ischemic stroke occurs when there is a blockage in the blood vessels supplying the brain, often due to a blood clot. A hemorrhagic stroke is caused by a burst blood vessel, which leads to bleeding in or around the brainstem.

Recognizing the symptoms of a brainstem stroke is crucial, as timely treatment improves the chances of recovery. Common symptoms include:

• Vertigo and dizziness
• Severe imbalance
• Double vision
• Slurred speech
• Decreased consciousness
• Locked-in syndrome, where survivors can only move their eyes
• Hearing and vision problems
• Problems with balance and coordination
• Difficulty swallowing or speaking
• Weakness on one side of the body
• Sudden severe headache
• Confusion
• Changes in alertness
• Difficulty breathing

It is important to note that brainstem strokes can be hard to diagnose as they may present with complex symptoms. A physical examination, neurological tests, brain imaging (CT scans, MRIs), and blood tests may be used to diagnose a brainstem stroke and determine its type and severity.

Brainstem stroke diagnosis

Brainstem strokes can be challenging to diagnose due to their complex symptoms and they are often identified through a combination of clinical assessment, laboratory studies, and imaging techniques. Here is an overview of the diagnostic process for brainstem strokes:

Clinical Assessment:

• A neurological exam is crucial for evaluating the patient's neurological status, including levels of consciousness, cranial nerve functions, motor and sensory functions, cerebellar signs, coordination, and gait.
• Assessment of vital signs, such as oxygen saturation, blood pressure, pulse rate, and respiratory rate, is essential.
• Obtaining a detailed medical history, including current medications, comorbidities, and risk factors, is vital for accurate diagnosis.

Laboratory Studies:

• Blood workup, including complete blood count, coagulation profile, renal function, lipid panel, and thyroid function tests, helps identify underlying causes and risk factors.
• Cardiovascular workup, such as electrocardiogram (ECG) or Holter monitor, echocardiogram, and cardiac enzyme tests, is performed to assess heart function and identify potential sources of emboli.

Imaging Studies:

• Computed Tomography (CT) scan: CT scans are often the first test performed in stroke evaluation. They can detect areas of abnormality in the brain, including bleeding or insufficient blood flow. CT angiography can evaluate blood flow in major arteries, while CT perfusion assesses blood flow at the capillary level.
• Magnetic Resonance Imaging (MRI): MRI scans provide detailed images of the brain and can detect infarction of brain tissue. They are particularly useful in evaluating the brainstem, which CT scans may not always image well.

Additional Tests:

• Sleep study or polysomnography: This test is considered if stroke etiology remains unclear, as sleep disorders can be a potential cause.
• Multi-phase CT angiography: This test evaluates the state of vertebral and carotid arteries and helps in endovascular management planning.

Types of Brainstem Strokes:

Brainstem strokes can be classified into two main types:

• Ischemic Brainstem Stroke: This is the most common type, caused by a blockage in a blood vessel supplying the brainstem, leading to insufficient blood flow.
• Hemorrhagic Brainstem Stroke: This type involves bleeding in or around the brainstem, often due to a ruptured blood vessel.

Treatment Options:

The treatment for brainstem strokes depends on the type and severity of the stroke and the patient's overall health. Time is critical in managing brainstem strokes to improve recovery:

• Emergency Treatment: In the first few hours to days, thrombolytic medications to dissolve clots, thrombectomy to remove clots, medications to minimize bleeding, and surgeries to repair ruptured blood vessels or relieve brain swelling may be employed.
• Ongoing Treatment: Long-term antiplatelet medications, such as Aspirin or Clopidogrel, and statins to lower cholesterol are often prescribed to prevent another stroke.
• Surgical Interventions: Surgical procedures are more common in hemorrhagic brainstem strokes and may include surgical clipping or coiling of aneurysms and surgeries to relieve pressure on the brain due to swelling.

Brainstem stroke treatment

A brain stem stroke is a blockage that obstructs the flow of blood to the brain stem, which is the base of the brain that connects to the spinal cord. The faster blood flow can be restored after a brain stem stroke, the better the chances for recovery.

Treatment Options for Brain Stem Stroke

There are several treatment options available for brain stem strokes. The treatment will depend on the type and severity of the stroke, as well as the patient's overall health. Treatment should begin as soon as possible to improve the chances of recovery. Here are some common treatment options:

• Thrombolytic medications: These are clot-busting drugs used when a blood vessel is blocked. They should be administered within a few hours of the onset of symptoms.
• Thrombectomy: A procedure to remove a blood clot from a blocked vessel.
• Medications to minimise bleeding: These are used if there is bleeding in the brain stem.
• Surgeries to repair ruptured or abnormal blood vessels: In some cases, surgery may be required to repair damaged blood vessels.
• Surgical interventions: These are more common in hemorrhagic cases and may include procedures such as surgical clipping or coiling of aneurysms.
• Breathing assistance: After a brain stem stroke, the patient may need help with breathing. This could involve inserting a tube down the windpipe or using a mask to deliver air through the nostrils.
• Physical and occupational therapy: Physical therapy focuses on improving motor skills, strength, and balance, while occupational therapy helps patients with everyday activities such as eating, dressing, and bathing.
• Speech and swallowing therapy: Many brain stem stroke survivors experience difficulties with speech and swallowing. Speech therapists work to improve communication and address swallowing difficulties.

Conservative Therapy

In some cases, brain stem strokes may be treated conservatively, especially for patients with smaller hematomas, a higher Glasgow Coma Scale (GCS) score, younger age, and no extra-pontine extension. Antiplatelet therapy using acetylsalicylic acid or dual therapy with clopidogrel may be administered within 24 to 48 hours after the onset of symptoms to improve patient outcomes.

Imaging Techniques for Brain Stem Stroke

Computed tomography (CT) scans and magnetic resonance imaging (MRI) scans are commonly used to evaluate brain stem strokes. CT scans are often one of the first tests performed as they can show areas of abnormalities in the brain and help determine the cause, such as insufficient blood flow or a ruptured blood vessel. However, CT scans may not always detect a stroke, especially in the cerebellum or brainstem, or if the stroke has occurred recently. In such cases, an MRI may be recommended as it can provide a more detailed image.

Brainstem stroke prevention

Brainstem strokes are life-threatening and can be difficult to diagnose. They are caused by a disruption to the blood supply to the brainstem, which controls vital functions such as breathing, heartbeat, blood pressure, speech, swallowing, hearing, and eye movements. The faster the blood flow is restored, the better the chances for recovery.

• Manage long-term health problems: Keep conditions such as high blood pressure and diabetes under control.
• Maintain a healthy weight: Eat a healthy diet and exercise regularly to stay within a healthy weight range.
• Eat a balanced diet: Consume a diet low in fat and cholesterol and rich in whole grains, fruits, and vegetables.
• Avoid smoking and vaping: Smoking and vaping can increase the risk of stroke, so it's best to quit or avoid these habits.
• Limit alcohol and drug use: Alcohol and drug use can negatively impact health and increase the risk of stroke.
• Follow doctor's recommendations: If you have a condition that increases the risk of stroke, such as hypertension or diabetes, follow your doctor's advice for managing it.

By following these guidelines and maintaining a healthy lifestyle, you can reduce your risk of experiencing a brainstem stroke.

Brainstem stroke syndromes

The clinical presentation of brainstem stroke syndromes varies depending on the affected area, but generally, there is ipsilateral cranial nerve palsy and contralateral hemiplegia/hemiparesis and/or hemisensory loss. The rule of four of the brainstem is a simple clinical tool to aid in localising signs and symptoms to specific areas of the brainstem.

Numerous brainstem stroke syndromes have been described, but many are rare and primarily of historical interest. The most common brainstem stroke syndrome is the lateral medullary syndrome (Wallenberg syndrome), caused by occlusion of the posterior inferior cerebellar artery (PICA) or its perforators from the vertebral artery. This syndrome presents with vertigo, nystagmus, nausea, dysphagia, dysarthria, and a range of sensory disturbances.

Other relatively common brainstem stroke syndromes include:

• Babinski-Nageotte syndrome: caused by a small lesion in the lateral medulla oblongata, combining features of medial and lateral medullary syndromes.
• Medial inferior pontine syndrome (Millard-Gubler syndrome): resulting from a lesion in the ventromedial caudal pons, presenting with diplopia, ataxia, hemiparesis, facial weakness, and gaze palsy.
• Lateral inferior pontine syndrome: due to lesions of the laterocaudal perforators of the anterior inferior cerebellar artery (AICA), leading to gaze paresis, facial paresis, impaired tactile and thermal sensation in the face, hemiataxia, and other symptoms.
• Medial superior pontine syndrome: caused by occlusion of paramedian and short circumferential branches of the basilar artery, presenting with paresis of masticatory muscles, sensory disturbances over the face, hemiataxia, and hemiparesis.
• Lateral superior pontine syndrome: resulting from occlusion of circumferential branches of the basilar artery and superior cerebellar artery, leading to hemiataxia, intention tremor, and hypesthesia in the face.

Frequently asked questions