From the Guidelines
Scalloping of the skull vault is not a typical finding in intracranial hypotension, and its presence should prompt a thorough evaluation for other conditions that may cause increased intracranial pressure. When considering the provided evidence, it's essential to note that intracranial hypotension is characterized by symptoms such as postural headaches, nausea, vomiting, neck pain, tinnitus, changes in hearing, and photophobia, as discussed in the study by 1. The pathophysiologic mechanism of headache symptoms and various neurological deficits in patients with intracranial hypotension is not well understood but likely multifactorial and may be attributed to compensatory venodilitation, blood volume expansion, and dural sinus stretching as the body attempts to maintain a stable intracranial volume in response to decreased CSF volume. Some key points to consider in the evaluation of intracranial hypotension include:
- The clinical syndrome of intracranial hypotension refers to the symptoms caused by cerebrospinal fluid (CSF) hypovolemia and is primarily characterized by postural headaches, as noted in the study by 1.
- The 3 main causes of intracranial hypotension are CSF leakage through a dural defect, leaking meningeal diverticulum, and CSF-venous fistula, as outlined in the study by 1.
- Imaging plays a critical role in the diagnostic evaluation of intracranial hypotension, with goals of confirming the diagnosis and localizing the source of leak for targeted therapy, as discussed in the study by 1. However, scalloping of the skull vault is more commonly associated with conditions that cause chronically increased intracranial pressure, such as hydrocephalus, intracranial tumors, idiopathic intracranial hypertension, and Chiari malformations. Given the potential for serious neurological complications, prompt neurological evaluation is necessary to determine the underlying cause of scalloping of the skull vault, and management should be tailored to the specific condition identified, as would be the approach in real-life clinical practice, considering the information provided by 1.
From the Research
Scalloping of the Skull Vault
- Scalloping of the skull vault refers to the erosion or thinning of the inner table of the skull, which can be caused by various lesions or conditions.
- According to 2, some benign entities in the skull vault region may mimic malignancy if analyzed using classical bone-tumor criteria, and proper patient management requires being familiar with these presentations.
- The imaging features of skull vault lesions can be categorized into four groups: pseudolesions, lytic, sclerotic, and transdiploic lesions 2.
- Scalloping of the skull vault can be associated with various conditions, including:
- Arachnoid granulations and meningo-/encephaloceles, which are pseudolesions that can cause scalloping of the inner table of the skull 2.
- Lytic lesions, such as fibrous dysplasia, epidermal inclusion and dermoid cysts, eosinophilic granuloma, hemangioma, aneurysmal bone cyst, giant cell tumor, metastasis, and myeloma, which can cause erosion or thinning of the skull vault 2.
- Sclerotic lesions, such as osteomas, osteosarcoma, and metastasis, which can cause thickening of the skull vault but may also be associated with scalloping in some cases 2.
- Imaging techniques, such as radiographs, CT, and MRI, can be used to evaluate skull vault lesions and identify scalloping 3, 4, 5.
- In some cases, scalloping of the skull vault can be associated with generalized thickening of the skull, as seen in conditions such as chronic severe anemia, Paget disease, and phenytoin therapy 6.