Leptomeningeal carcinomatosis mimicking Creutzfeldt-Jakob disease: clinical features, laboratory tests, MRI images, EEG findings in an autopsy-proven case

Spectrum of EEG Findings in Patients with Leptomeningeal Carcinomatosis and Seizures: Correlation with Neurodiagnostic Results and Outcome

Purpose: Leptomeningeal carcinomatosis (LC) is a devastating condition in patients with systemic malignancies or primary brain tumors. Although much is known about neuro-radiologic investigations, there is very little information about EEG findings in these patients. Whether EEG is correlated with cranial magnetic resonance imaging (MRI) results and survival has not been investigated. Methods: Medical records of 2340 adult patients with the diagnosis of brain tumor, either metastatic (Group 1) or primary (Group 2), between 2000-2021 were reviewed for the presence of LC and seizures. Demographic and clinical features, laboratory results and Karnofsky performance scores of included patients were noted. Available routine EEG recordings were re-evaluated. Any possible correlation between EEG findings-MRI and EEG findings-survival were investigated statistically. Results: Sixty-six patients with LC and seizures were identified. The most common malignancies were lung cancer and glioblastoma multiforme. Twenty-six EEG recordings of 17 patients in Group 1, and 13 EEGs of 9 patients in Group 2 were available for final analysis. The most common EEG characteristic was background slowing (73%). The most frequent findings were rhythmic periodic patterns or spike wave activity (27%). Sporadic epileptiform discharges (8%) or ictal recordings (4%) were very rare. None of the EEG features correlated with MRI results or survival. Conclusion: There are various EEG patterns in patients with LC and seizures. The most common findings are related to background activity, with rhythmic periodic patterns or spike wave activity being observed less commonly. EEG characteristics do not predict MRI findings or survival.

Band-Like Brainstem Lesion in a Patient With a History of Lung Adenocarcinoma

Leptomeningeal metastasis (LM) is a severe complication of primary malignancy that has spread to the leptomeninges and cerebrospinal fluid (CSF). Here, we report a patient whose magnetic resonance imaging (MRI) showed a unique brainstem lesion suspicious of LM. A 72-year-old man presented with dizziness, gait instability, and cognitive decline, primarily object naming. He had a history of lung adenocarcinoma with epidermal growth factor receptor (EGFR) mutation. Brain MRI revealed a band-like lesion surrounding the ventral brainstem with T2 weighted-image/fluid attenuation inversion recovery (FLAIR) imaging and diffusion-weighted imaging (DWI) hyperintensity without gadolinium enhancement. No malignant cells were detected in the CSF. He underwent ventriculoperitoneal shunt two months after the onset, and his gait improved, but his cognitive function declined further. Recent reports suggest similar brainstem lesions as a unique LM pattern, which occurs almost exclusively in patients with lung adenocarcinoma with EGFR mutation. Therefore, if MRI shows this brainstem finding, repeated and appropriate CSF cytology is needed to detect tumor cells. Furthermore, if a patient with lung adenocarcinoma shows a cognitive decline, cerebral LM and auto-antibodies that mainly target neuronal surface antigens should be considered.

Pathological Features of Brain Metastases

Metastases are the most common intracranial tumors in adults. Lung cancer, melanoma, renal cell carcinoma, and breast cancer are the most common primary tumors that metastasize to the brain. Improved detection of small metastases by MRI, and improved systemic therapy for primary tumors, resulted in increased incidence of brain metastasis. Advances in neuroanesthesia and neurosurgery have significantly improved the safety of surgical resection of brain metastases. Surgical approach and active management have become applicable for many patients. Subsequently, brain metastases diagnosis no longer equals palliative treatment. Moreover, the demand for diagnosing brain masses has increased with its associated challenges.

Triphasic waves in electroencephalogram as a possible early marker of carcinomatous meningitis: a case report

RATIONALE

Carcinomatous meningitis is a rare neurological complication. This condition is difficult to diagnose, and misdiagnosis is common because the clinical manifestations are variable. Cerebrospinal fluid (CSF) cytology is the gold standard for diagnosis. Repeated lumbar puncture is required because of the low positive rate. Our case showed triphasic waves (TWs) in an electroencephalogram (EEG) before cancer cells were detected in cytology. We report this case to demonstrate that TWs in EEG may be a prognostic marker in patients with carcinomatous meningitis.

PATIENT CONCERNS

A 76-year-old Chinese male displayed incremental headache, nausea, emesis, and intermittent fever for 2 months. A routine scalp EEG showed mild slow background activity. The CSF analysis demonstrated a slight increase in protein, and the white blood cell count was in the normal range. Cytology did not show any atypical cells. Viral meningitis was considered for the first time.

DIAGNOSIS

After admission, a long-term EEG was performed because of his fever and mild abnormalities in the routine EEG. The second EEG showed asymmetric TWs in the frontal brain regions. Lung adenocarcinoma was found after systemic investigation. Finally, the patient was diagnosed with carcinomatous meningitis based on repeated CSF cytology.

INTERVENTIONS

The patient received systemic chemotherapy in the Department of Oncology.

OUTCOMES

The patient was followed up monthly, and he was lost to follow-up in the sixth month after carcinomatous meningitis was diagnosed.

LESSONS

It is difficult to make a diagnosis in the early stage of carcinomatous meningitis because the clinical manifestations lack specificity. Repeated lumbar puncture is time consuming and is painful for the patients. In our case, TWs in EEG were detected before cancer cells were found in cytology. EEG should be performed when carcinomatous meningitis is under consideration.