Neurologic Manifestations of Glioblastoma Multiforme Clinical Presentation

Updated: Oct 09, 2020
  • Author: ABM Salah Uddin, MD; Chief Editor: Stephen A Berman, MD, PhD, MBA  more...
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Glioblastoma multiforme (GBM), like other brain tumors, produces symptoms by a combination of focal neurologic deficits from compression and infiltration of the surrounding brain, vascular compromise, and raised intracranial pressure. Presenting features include the following:

  • Headaches (30-50%): Headaches are nonspecific and indistinguishable from tension headache. As the tumor enlarges, it may have features of increased intracranial pressure.

  • Seizures (30-60%): Depending on the tumor location, seizures may be simple partial, complex partial, or generalized.

  • Focal neurologic deficits (40-60%): As some patients with GBM survive longer, an increasing number of patients experience cognitive problems, neurologic deficits resulting from radiation necrosis, communicating hydrocephalus, and occasionally cranial neuropathies and polyradiculopathies from leptomeningeal spread.

  • Mental status changes (20-40%): With the advent of MRI, GBMs are increasingly diagnosed at an earlier stage and with subtle personality changes.



Physical findings depend on the location, size, and rate of growth of the tumor, as with any other CNS tumor. Tumors in less critical areas (eg, anterior frontal or temporal lobe) may present with subtle personality changes and memory problems. Similarly, motor weakness and sensory hemineglect are the hallmarks of tumors arising in the frontal or parietal lobes and thalamic regions. Sensory neglect is more prominent in right hemispheric lesions. Note the following:

  • Seizures are a common presentation of small tumors in the frontoparietal regions (simple motor or sensory partial seizure) and temporal lobe (simple or complex partial seizure).

  • Occipital lobe tumors may present with visual field defects. Although these tumors are less frequent than tumors originating at other sites, patients generally are unaware of the slow onset of a cortically based hemianopsia.

  • Brainstem GBMs are rare in adults. However, they may present with bilateral crossed neurological deficits (eg, weakness on one side with contralateral cranial nerve palsy). Alternatively, they may present with rapidly progressive headache or altered consciousness.



The etiology of GBM is unknown. However, at least 2 genetic pathways have been delineated in its development: de novo (primary) glioblastomas and secondary glioblastomas. De novo glioblastomas are most common. De novo GBM develops in older patients and demonstrates a high rate of epidermal growth factor receptor (EGFR) overexpression, phosphatase and tensin homologue deleted on chromosome 10 (PTEN) mutations, and p16INK4A deletions. In contrast, secondary GBM develops in younger patients and develops from a malignant transformation of a previously diagnosed low-grade tumor. TP53 and retinoblastoma gene (RB) mutations are more common in the development of secondary glioblastomas.

Several genetic disorders are associated with increased incidence of gliomas (eg, tuberous sclerosis, neurofibromatosis type 1 and type 2, Turcot syndrome, Li-Fraumeni syndrome). An association exists between ionizing radiation and astrocytomas. Children who receive low-dose intracranial radiation have a 2.6-fold increase in prevalence of astrocytomas, and prophylactic whole-brain radiation therapy in patients with acute lymphocytic leukemia increased the incidence of astrocytomas 22-fold.

Other suspected risk factors, such as electromagnetic radiation and cellular telephone use, are yet to be substantiated by large epidemiologic studies. However, researchers reviewed 16 published studies that looked at cell phone use and the risk of brain cancers and concluded that using cell phones for more than 10 years gives a consistent pattern of increased risk of at least 2 types of brain cancer such as acoustic neuroma and gliomas. The risk is significantly higher for the ipsilateral exposure (tumor on the same side of the brain as cell phone exposure). [14]