From the Guidelines
For the follow-up of encephalomalacia, whether acute or chronic, Brain MRI is the most useful initial imaging modality, particularly for evaluating subacute or chronic head trauma with unexplained cognitive or neurologic deficits. This recommendation is based on the most recent and highest quality study available, which emphasizes the sensitivity of MRI for subtle findings adjacent to the calvarium or skull base, such as focal encephalomalacia, and for small white matter lesions (microbleeds) as chronic sequelae of previous traumatic axonal injury or DAI 1.
When considering the follow-up for encephalomalacia, it's crucial to differentiate between acute and chronic forms due to their distinct management approaches and prognoses. Key points to consider include:
- The timeline of development: Acute encephalomalacia occurs immediately following a severe brain injury, while chronic encephalomalacia develops over weeks to months after the initial injury.
- Presentation and symptoms: Acute cases present with sudden neurological deficits, symptoms like headache, altered consciousness, seizures, or focal neurological signs, whereas chronic cases show more stable neurological deficits that may have partially improved from the acute phase.
- Imaging characteristics: Acute cases are characterized by edema, mass effect, and sometimes hemorrhage on CT or MRI, while chronic cases display well-defined hypodense areas with volume loss and no enhancement.
Given the importance of accurate diagnosis and the role of imaging in differentiating between acute and chronic encephalomalacia, the use of conventional MRI, including T1-weighted, T2-weighted, T2-weighted (gradient-echo), and diffusion-weighted imaging, is recommended. Additionally, susceptibility-weighted imaging, a high-resolution 3-D T2-weighted sequence, can increase sensitivity for paramagnetic blood products, such as microbleeds, which are indicative of chronic sequelae of previous traumatic axonal injury or DAI 1.
In terms of prognostication, conventional MRI may help predict long-term neurocognitive sequelae, with abnormalities on early subacute MRI being clinically relevant in improving the prediction of 3-month outcomes 1. Furthermore, the presence of frontal-temporal-parietal microbleeds on early MRI susceptibility-weighted imaging has been correlated with the presence or absence of depressive symptoms at 1 year after injury, highlighting the potential of MRI in predicting long-term outcomes 1.
Therefore, for both acute and chronic encephalomalacia, a comprehensive follow-up strategy should include regular Brain MRI assessments, tailored to the individual's clinical presentation and progression, to guide management decisions and predict potential long-term sequelae 1.
From the Research
Encephalomalacia: Acute vs Chronic
- Encephalomalacia is the softening or loss of brain tissue after cerebral infarction, cerebral ischemia, infection, craniocerebral trauma, or other injury 2.
- The term is usually used during gross pathologic inspection to describe blurred cortical margins and decreased consistency of brain tissue after infarction.
- Multicystic encephalomalacia refers to the formation of multiple cystic cavities of various sizes in the cerebral cortex of neonates and infants after injury, most notably perinatal hypoxic-ischemic events.
Acute Encephalomalacia
- Acute encephalomalacia can occur after a penetrating brain injury, such as during endoscopic sinus surgery 2.
- It can also occur after acute ischemic stroke, and the presence of encephalomalacia can impact the accuracy of automated Alberta Stroke Program Early CT Score (ASPECTS) 3.
- In patients with acute ischemic stroke, the presence of encephalomalacia or extensive white matter hyperintensities can result in a lower automated ASPECTS than radiologist-consensus ASPECTS 3.
Chronic Encephalomalacia
- Chronic encephalomalacia can be a cause of medically intractable partial epilepsy, and resection of the encephalomalacia can be an effective treatment 4.
- The presence of a focal fast frequency discharge at the beginning of seizures on scalp EEG can be predictive of seizure-free outcome after resection of encephalomalacia 4.
- Complete resection of the encephalomalacia should be attempted, as it may be a favorable predictive factor for seizure-free outcome 4.
Treatment and Management
- Levetiracetam is an antiepileptic drug that can be used to treat seizures associated with encephalomalacia 5, 6.
- It has a novel structure and unique mechanisms of action, and is associated with rapid and complete absorption, high oral bioavailability, and minimal metabolism 6.
- Levetiracetam is generally well-tolerated, but can be associated with behavioral adverse effects in some patients 6.