Neural storming, also known as neurostorming or paroxysmal sympathetic hyperactivity (PSH), is a complex neurological phenomenon. It primarily affects individuals who have experienced severe traumatic brain injuries (TBI). This condition involves an overactive sympathetic nervous system, which is responsible for the body’s “fight-or-flight” response, leading to a range of involuntary symptoms.
The Body’s “Fight or Flight” System Gone Awry
The sympathetic nervous system (SNS) is a component of the autonomic nervous system, which controls involuntary bodily functions. Normally, the SNS prepares the body for perceived threats by initiating the “fight-or-flight” response, increasing heart rate, blood pressure, and alertness. After the threat passes, the parasympathetic nervous system (PNS) restores the body to a calm state by lowering these functions.
In individuals with severe traumatic brain injury, the delicate balance between the sympathetic and parasympathetic nervous systems can be disrupted. Damage to brain regions, particularly those influencing the hypothalamus, can lead to the brain being unable to accurately determine if a threat is present. This dysregulation causes the sympathetic nervous system to go into overdrive, resulting in a continuous release of stress hormones like adrenaline. This prolonged state of heightened alert places immense stress on the body and can occur spontaneously or be triggered by various stimuli, such as changes in medication, body repositioning, or environmental noise.
Key Indicators of Neural Storming
Neural storming manifests through a cluster of physical symptoms that reflect the overactivity of the sympathetic nervous system. One common sign is an elevated heart rate, tachycardia, which can exceed 130 beats per minute.
Patients may also experience a high fever, known as hyperthermia, as the body’s temperature regulation becomes dysregulated. Increased blood pressure, or hypertension, is another symptom, often fluctuating dramatically during episodes. Excessive sweating, or diaphoresis, is observed, sometimes profusely.
Breathing can become rapid, known as tachypnea, and pupils may dilate. Muscle rigidity and involuntary posturing, such as dystonia, are also characteristic, including extensor or decerebrate posturing. Patients may also exhibit general restlessness or agitation. These symptoms appear within days of a severe brain injury and can last from minutes to hours, sometimes occurring multiple times daily.
Approaches to Diagnosis and Management
Diagnosing neural storming primarily relies on clinical observation of symptoms in patients who have sustained a traumatic brain injury, after ruling out other potential causes. Distinguishing neural storming from conditions like seizures, infections, or medication withdrawal can be challenging due to overlapping symptoms.
Treatment strategies for neural storming involve a multimodal approach to control the overactive sympathetic nervous system and provide supportive care. Pharmacological interventions are used, including beta-blockers like propranolol or labetalol to manage tachycardia and hypertension.
Sedatives such as benzodiazepines (e.g., diazepam, midazolam) or propofol can reduce agitation and sympathetic outflow. Other medications may include gabapentin or baclofen for muscle spasticity, and opioids like morphine or fentanyl for severe episodes or pain management. Clonidine, an alpha-2 agonist, can also be used to directly reduce sympathetic activity.
Supportive care is important. This includes maintaining proper hydration, providing nutritional support to counter increased metabolism, and implementing physical therapy to address muscle rigidity.
Navigating the Recovery Journey
Prolonged or severe neural storming can lead to several complications. The sustained hypermetabolic state, where the body’s energy needs can increase by 100-200%, results in significant weight loss and muscle atrophy.
Excessive sweating and increased metabolism also raise the risk of dehydration. The continuous stress on the body contributes to pressure sores, increased risk of infections, and potential damage to cardiac and skeletal muscle fibers.
Outcomes for individuals affected by neural storming vary widely, depending on the severity of the initial brain injury and the effectiveness and timeliness of symptom management. While neural storming itself does not directly cause death, complications can be life-threatening if left untreated. Ongoing rehabilitative care is important for these patients. Gradual weaning off medications as the patient recovers is important, as sudden discontinuation can trigger episodes.